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Sample records for biosynthetic gene phld

  1. Heterologous expression of pikromycin biosynthetic gene cluster using Streptomyces artificial chromosome system.

    Science.gov (United States)

    Pyeon, Hye-Rim; Nah, Hee-Ju; Kang, Seung-Hoon; Choi, Si-Sun; Kim, Eung-Soo

    2017-05-31

    Heterologous expression of biosynthetic gene clusters of natural microbial products has become an essential strategy for titer improvement and pathway engineering of various potentially-valuable natural products. A Streptomyces artificial chromosomal conjugation vector, pSBAC, was previously successfully applied for precise cloning and tandem integration of a large polyketide tautomycetin (TMC) biosynthetic gene cluster (Nah et al. in Microb Cell Fact 14(1):1, 2015), implying that this strategy could be employed to develop a custom overexpression scheme of natural product pathway clusters present in actinomycetes. To validate the pSBAC system as a generally-applicable heterologous overexpression system for a large-sized polyketide biosynthetic gene cluster in Streptomyces, another model polyketide compound, the pikromycin biosynthetic gene cluster, was preciously cloned and heterologously expressed using the pSBAC system. A unique HindIII restriction site was precisely inserted at one of the border regions of the pikromycin biosynthetic gene cluster within the chromosome of Streptomyces venezuelae, followed by site-specific recombination of pSBAC into the flanking region of the pikromycin gene cluster. Unlike the previous cloning process, one HindIII site integration step was skipped through pSBAC modification. pPik001, a pSBAC containing the pikromycin biosynthetic gene cluster, was directly introduced into two heterologous hosts, Streptomyces lividans and Streptomyces coelicolor, resulting in the production of 10-deoxymethynolide, a major pikromycin derivative. When two entire pikromycin biosynthetic gene clusters were tandemly introduced into the S. lividans chromosome, overproduction of 10-deoxymethynolide and the presence of pikromycin, which was previously not detected, were both confirmed. Moreover, comparative qRT-PCR results confirmed that the transcription of pikromycin biosynthetic genes was significantly upregulated in S. lividans containing tandem

  2. Regulation of Flavonoid Biosynthetic Genes in Germinating Arabidopsis Seedlings.

    Science.gov (United States)

    Kubasek, WL; Shirley, BW; McKillop, A; Goodman, HM; Briggs, W; Ausubel, FM

    1992-01-01

    Many higher plants, including Arabidopsis, transiently display purple anthocyanin pigments just after seed germination. We observed that steady state levels of mRNAs encoded by four flavonoid biosynthetic genes, PAL1 (encoding phenylalanine ammonia-lyase 1), CHS (encoding chalcone synthase), CHI (encoding chalcone isomerase), and DFR (encoding dihydroflavonol reductase), were temporally regulated, peaking in 3-day-old seedlings grown in continuous white light. Except for the case of PAL1 mRNA, mRNA levels for these flavonoid genes were very low in seedlings grown in darkness. Light induction studies using seedlings grown in darkness showed that PAL1 mRNA began to accumulate before CHS and CHI mRNAs, which, in turn, began to accumulate before DFR mRNA. This order of induction is the same as the order of the biosynthetic steps in flavonoid biosynthesis. Our results suggest that the flavonoid biosynthetic pathway is coordinately regulated by a developmental timing mechanism during germination. Blue light and UVB light induction experiments using red light- and dark-grown seedlings showed that the flavonoid biosynthetic genes are induced most effectively by UVB light and that blue light induction is mediated by a specific blue light receptor. PMID:12297632

  3. Functional conservation of coenzyme Q biosynthetic genes among yeasts, plants, and humans.

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    Kazuhiro Hayashi

    Full Text Available Coenzyme Q (CoQ is an essential factor for aerobic growth and oxidative phosphorylation in the electron transport system. The biosynthetic pathway for CoQ has been proposed mainly from biochemical and genetic analyses of Escherichia coli and Saccharomyces cerevisiae; however, the biosynthetic pathway in higher eukaryotes has been explored in only a limited number of studies. We previously reported the roles of several genes involved in CoQ synthesis in the fission yeast Schizosaccharomyces pombe. Here, we expand these findings by identifying ten genes (dps1, dlp1, ppt1, and coq3-9 that are required for CoQ synthesis. CoQ10-deficient S. pombe coq deletion strains were generated and characterized. All mutant fission yeast strains were sensitive to oxidative stress, produced a large amount of sulfide, required an antioxidant to grow on minimal medium, and did not survive at the stationary phase. To compare the biosynthetic pathway of CoQ in fission yeast with that in higher eukaryotes, the ability of CoQ biosynthetic genes from humans and plants (Arabidopsis thaliana to functionally complement the S. pombe coq deletion strains was determined. With the exception of COQ9, expression of all other human and plant COQ genes recovered CoQ10 production by the fission yeast coq deletion strains, although the addition of a mitochondrial targeting sequence was required for human COQ3 and COQ7, as well as A. thaliana COQ6. In summary, this study describes the functional conservation of CoQ biosynthetic genes between yeasts, humans, and plants.

  4. Characterization of the biosynthetic gene cluster for cryptic phthoxazolin A in Streptomyces avermitilis.

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    Dian Anggraini Suroto

    Full Text Available Phthoxazolin A, an oxazole-containing polyketide, has a broad spectrum of anti-oomycete activity and herbicidal activity. We recently identified phthoxazolin A as a cryptic metabolite of Streptomyces avermitilis that produces the important anthelmintic agent avermectin. Even though genome data of S. avermitilis is publicly available, no plausible biosynthetic gene cluster for phthoxazolin A is apparent in the sequence data. Here, we identified and characterized the phthoxazolin A (ptx biosynthetic gene cluster through genome sequencing, comparative genomic analysis, and gene disruption. Sequence analysis uncovered that the putative ptx biosynthetic genes are laid on an extra genomic region that is not found in the public database, and 8 open reading frames in the extra genomic region could be assigned roles in the biosynthesis of the oxazole ring, triene polyketide and carbamoyl moieties. Disruption of the ptxA gene encoding a discrete acyltransferase resulted in a complete loss of phthoxazolin A production, confirming that the trans-AT type I PKS system is responsible for the phthoxazolin A biosynthesis. Based on the predicted functional domains in the ptx assembly line, we propose the biosynthetic pathway of phthoxazolin A.

  5. Minimum Information about a Biosynthetic Gene cluster : commentary

    NARCIS (Netherlands)

    Medema, Marnix H; Kottmann, Renzo; Yilmaz, Pelin; Cummings, Matthew; Biggins, John B; Blin, Kai; de Bruijn, Irene; Chooi, Yit Heng; Claesen, Jan; Coates, R Cameron; Cruz-Morales, Pablo; Duddela, Srikanth; Dusterhus, Stephanie; Edwards, Daniel J; Fewer, David P; Garg, Neha; Geiger, Christoph; Gomez-Escribano, Juan Pablo; Greule, Anja; Hadjithomas, Michalis; Haines, Anthony S; Helfrich, Eric J N; Hillwig, Matthew L; Ishida, Keishi; Jones, Adam C; Jones, Carla S; Jungmann, Katrin; Kegler, Carsten; Kim, Hyun Uk; Kotter, Peter; Krug, Daniel; Masschelein, Joleen; Melnik, Alexey V; Mantovani, Simone M; Monroe, Emily A; Moore, Marcus; Moss, Nathan; Nutzmann, Hans-Wilhelm; Pan, Guohui; Pati, Amrita; Petras, Daniel; Reen, F Jerry; Rosconi, Federico; Rui, Zhe; Tian, Zhenhua; Tobias, Nicholas J; Tsunematsu, Yuta; Wiemann, Philipp; Wyckoff, Elizabeth; Yan, Xiaohui; Yim, Grace; Yu, Fengan; Xie, Yunchang; Aigle, Bertrand; Apel, Alexander K; Balibar, Carl J; Balskus, Emily P; Barona-Gomez, Francisco; Bechthold, Andreas; Bode, Helge B; Borriss, Rainer; Brady, Sean F; Brakhage, Axel A; Caffrey, Patrick; Cheng, Yi-Qiang; Clardy, Jon; Cox, Russell J; De Mot, Rene; Donadio, Stefano; Donia, Mohamed S; van der Donk, Wilfred A; Dorrestein, Pieter C; Doyle, Sean; Driessen, Arnold J M; Ehling-Schulz, Monika; Entian, Karl-Dieter; Fischbach, Michael A; Gerwick, Lena; Gerwick, William H; Gross, Harald; Gust, Bertolt; Hertweck, Christian; Hofte, Monica; Jensen, Susan E; Ju, Jianhua; Katz, Leonard; Kaysser, Leonard; Klassen, Jonathan L; Keller, Nancy P; Kormanec, Jan; Kuipers, Oscar P; Kuzuyama, Tomohisa; Kyrpides, Nikos C; Kwon, Hyung-Jin; Lautru, Sylvie; Lavigne, Rob; Lee, Chia Y; Linquan, Bai; Liu, Xinyu; Liu, Wen; Luzhetskyy, Andriy; Mahmud, Taifo; Mast, Yvonne; Mendez, Carmen; Metsa-Ketela, Mikko; Micklefield, Jason; Mitchell, Douglas A; Moore, Bradley S; Moreira, Leonilde M; Muller, Rolf; Neilan, Brett A; Nett, Markus; Nielsen, Jens; O'Gara, Fergal; Oikawa, Hideaki; Osbourn, Anne; Osburne, Marcia S; Ostash, Bohdan; Payne, Shelley M; Pernodet, Jean-Luc; Petricek, Miroslav; Piel, Jorn; Ploux, Olivier; Raaijmakers, Jos M; Salas, Jose A; Schmitt, Esther K; Scott, Barry; Seipke, Ryan F; Shen, Ben; Sherman, David H; Sivonen, Kaarina; Smanski, Michael J; Sosio, Margherita; Stegmann, Evi; Sussmuth, Roderich D; Tahlan, Kapil; Thomas, Christopher M; Tang, Yi; Truman, Andrew W; Viaud, Muriel; Walton, Jonathan D; Walsh, Christopher T; Weber, Tilmann; van Wezel, Gilles P; Wilkinson, Barrie; Willey, Joanne M; Wohlleben, Wolfgang; Wright, Gerard D; Ziemert, Nadine; Zhang, Changsheng; Zotchev, Sergey B; Breitling, Rainer; Takano, Eriko; Glockner, Frank Oliver

    A wide variety of enzymatic pathways that produce specialized metabolites in bacteria, fungi and plants are known to be encoded in biosynthetic gene clusters. Information about these clusters, pathways and metabolites is currently dispersed throughout the literature, making it difficult to exploit.

  6. Expression profile of genes coding for carotenoid biosynthetic ...

    Indian Academy of Sciences (India)

    Expression profile of genes coding for carotenoid biosynthetic pathway during ripening and their association with accumulation of lycopene in tomato fruits. Shuchi Smita, Ravi Rajwanshi, Sangram Keshari Lenka, Amit Katiyar, Viswanathan Chinnusamy and. Kailash Chander Bansal. J. Genet. 92, 363–368. Table 1.

  7. Ancient horizontal gene transfer from bacteria enhances biosynthetic capabilities of fungi.

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    Imke Schmitt

    Full Text Available Polyketides are natural products with a wide range of biological functions and pharmaceutical applications. Discovery and utilization of polyketides can be facilitated by understanding the evolutionary processes that gave rise to the biosynthetic machinery and the natural product potential of extant organisms. Gene duplication and subfunctionalization, as well as horizontal gene transfer are proposed mechanisms in the evolution of biosynthetic gene clusters. To explain the amount of homology in some polyketide synthases in unrelated organisms such as bacteria and fungi, interkingdom horizontal gene transfer has been evoked as the most likely evolutionary scenario. However, the origin of the genes and the direction of the transfer remained elusive.We used comparative phylogenetics to infer the ancestor of a group of polyketide synthase genes involved in antibiotic and mycotoxin production. We aligned keto synthase domain sequences of all available fungal 6-methylsalicylic acid (6-MSA-type PKSs and their closest bacterial relatives. To assess the role of symbiotic fungi in the evolution of this gene we generated 24 6-MSA synthase sequence tags from lichen-forming fungi. Our results support an ancient horizontal gene transfer event from an actinobacterial source into ascomycete fungi, followed by gene duplication.Given that actinobacteria are unrivaled producers of biologically active compounds, such as antibiotics, it appears particularly promising to study biosynthetic genes of actinobacterial origin in fungi. The large number of 6-MSA-type PKS sequences found in lichen-forming fungi leads us hypothesize that the evolution of typical lichen compounds, such as orsellinic acid derivatives, was facilitated by the gain of this bacterial polyketide synthase.

  8. Diurnal and circadian expression profiles of glycerolipid biosynthetic genes in Arabidopsis.

    Science.gov (United States)

    Nakamura, Yuki; Andrés, Fernando; Kanehara, Kazue; Liu, Yu-chi; Coupland, George; Dörmann, Peter

    2014-01-01

    Glycerolipid composition in plant membranes oscillates in response to diurnal change. However, its functional significance remained unclear. A recent discovery that Arabidopsis florigen FT binds diurnally oscillating phosphatidylcholine molecules to promote flowering suggests that diurnal oscillation of glycerolipid composition is an important input in flowering time control. Taking advantage of public microarray data, we globally analyzed the expression pattern of glycerolipid biosynthetic genes in Arabidopsis under long-day, short-day, and continuous light conditions. The results revealed that 12 genes associated with glycerolipid metabolism showed significant oscillatory profiles. Interestingly, expression of most of these genes followed circadian profiles, suggesting that glycerolipid biosynthesis is partially under clock regulation. The oscillating expression profile of one representative gene, PECT1, was analyzed in detail. Expression of PECT1 showed a circadian pattern highly correlated with that of the clock-regulated gene GIGANTEA. Thus, our study suggests that a considerable number of glycerolipid biosynthetic genes are under circadian control.

  9. A genomics based discovery of secondary metabolite biosynthetic gene clusters in Aspergillus ustus.

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    Borui Pi

    Full Text Available Secondary metabolites (SMs produced by Aspergillus have been extensively studied for their crucial roles in human health, medicine and industrial production. However, the resulting information is almost exclusively derived from a few model organisms, including A. nidulans and A. fumigatus, but little is known about rare pathogens. In this study, we performed a genomics based discovery of SM biosynthetic gene clusters in Aspergillus ustus, a rare human pathogen. A total of 52 gene clusters were identified in the draft genome of A. ustus 3.3904, such as the sterigmatocystin biosynthesis pathway that was commonly found in Aspergillus species. In addition, several SM biosynthetic gene clusters were firstly identified in Aspergillus that were possibly acquired by horizontal gene transfer, including the vrt cluster that is responsible for viridicatumtoxin production. Comparative genomics revealed that A. ustus shared the largest number of SM biosynthetic gene clusters with A. nidulans, but much fewer with other Aspergilli like A. niger and A. oryzae. These findings would help to understand the diversity and evolution of SM biosynthesis pathways in genus Aspergillus, and we hope they will also promote the development of fungal identification methodology in clinic.

  10. A Genomics Based Discovery of Secondary Metabolite Biosynthetic Gene Clusters in Aspergillus ustus

    Science.gov (United States)

    Pi, Borui; Yu, Dongliang; Dai, Fangwei; Song, Xiaoming; Zhu, Congyi; Li, Hongye; Yu, Yunsong

    2015-01-01

    Secondary metabolites (SMs) produced by Aspergillus have been extensively studied for their crucial roles in human health, medicine and industrial production. However, the resulting information is almost exclusively derived from a few model organisms, including A. nidulans and A. fumigatus, but little is known about rare pathogens. In this study, we performed a genomics based discovery of SM biosynthetic gene clusters in Aspergillus ustus, a rare human pathogen. A total of 52 gene clusters were identified in the draft genome of A. ustus 3.3904, such as the sterigmatocystin biosynthesis pathway that was commonly found in Aspergillus species. In addition, several SM biosynthetic gene clusters were firstly identified in Aspergillus that were possibly acquired by horizontal gene transfer, including the vrt cluster that is responsible for viridicatumtoxin production. Comparative genomics revealed that A. ustus shared the largest number of SM biosynthetic gene clusters with A. nidulans, but much fewer with other Aspergilli like A. niger and A. oryzae. These findings would help to understand the diversity and evolution of SM biosynthesis pathways in genus Aspergillus, and we hope they will also promote the development of fungal identification methodology in clinic. PMID:25706180

  11. Expression of Xanthophyll Biosynthetic Genes during Light-Dependent Chloroplast Differentiation1

    Science.gov (United States)

    Woitsch, Sonja; Römer, Susanne

    2003-01-01

    In higher plants, etioplast to chloroplast differentiation is characterized by dramatic ultrastructural changes of the plastid and a concomitant increase in chlorophylls and carotenoids. Whereas the formation and function of carotenes and their oxygenated derivatives, the xanthophylls, have been well studied, little is known about the regulation of the genes involved in xanthophyll biosynthesis. Here, we analyze the expression of three xanthophyll biosynthetic genes (i.e. β-carotene hydroxylase [bhy], zeaxanthin epoxidase [zep], and violaxanthin de-epoxidase [vde]) during de-etiolation of seedlings of tobacco (Nicotiana tabacum L. cv Samsun) under different light conditions. White-light illumination caused an increase in the amount of all corresponding mRNAs. The expression profiles of bhy and zep not only resembled each other but were also similar to the pattern of a gene encoding a major light-harvesting protein of photosystem II. This finding indicates a coordinated synthesis during formation of the antenna complex. In contrast, the expression pattern of vde was clearly different. Furthermore, the gene expression of bhy was shown to be modulated after illumination with different white-light intensities. The expression of all xanthophyll biosynthetic genes under examination was up-regulated upon exposure to red, blue, and white light. Gene expression of bhy and vde but not of zep was more pronounced under red-light illumination, pointing at an involvement of the phytochrome system. Expression analysis in the presence of the photosynthetic electron transport inhibitors 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone indicated a redox control of transcription of two of the xanthophyll biosynthetic genes (bhy and zep). PMID:12857831

  12. Accumulation of Rutin and Betulinic Acid and Expression of Phenylpropanoid and Triterpenoid Biosynthetic Genes in Mulberry (Morus alba L.).

    Science.gov (United States)

    Zhao, Shicheng; Park, Chang Ha; Li, Xiaohua; Kim, Yeon Bok; Yang, Jingli; Sung, Gyoo Byung; Park, Nam Il; Kim, Soonok; Park, Sang Un

    2015-09-30

    Mulberry (Morus alba L.) is used in traditional Chinese medicine and is the sole food source of the silkworm. Here, 21 cDNAs encoding phenylpropanoid biosynthetic genes and 21 cDNAs encoding triterpene biosynthetic genes were isolated from mulberry. The expression levels of genes involved in these biosynthetic pathways and the accumulation of rutin, betulin, and betulinic acid, important secondary metabolites, were investigated in different plant organs. Most phenylpropanoid and triterpene biosynthetic genes were highly expressed in leaves and/or fruit, and most genes were downregulated during fruit ripening. The accumulation of rutin was more than fivefold higher in leaves than in other organs, and higher levels of betulin and betulinic acid were found in roots and leaves than in fruit. By comparing the contents of these compounds with gene expression levels, we speculate that MaUGT78D1 and MaLUS play important regulatory roles in the rutin and betulin biosynthetic pathways.

  13. Recent development of antiSMASH and other computational approaches to mine secondary metabolite biosynthetic gene clusters

    DEFF Research Database (Denmark)

    Blin, Kai; Kim, Hyun Uk; Medema, Marnix H.

    2017-01-01

    Many drugs are derived from small molecules produced by microorganisms and plants, so-called natural products. Natural products have diverse chemical structures, but the biosynthetic pathways producing those compounds are often organized as biosynthetic gene clusters (BGCs) and follow a highly...... conserved biosynthetic logic. This allows for the identification of core biosynthetic enzymes using genome mining strategies that are based on the sequence similarity of the involved enzymes/genes. However, mining for a variety of BGCs quickly approaches a complexity level where manual analyses...... are no longer possible and require the use of automated genome mining pipelines, such as the antiSMASH software. In this review, we discuss the principles underlying the predictions of antiSMASH and other tools and provide practical advice for their application. Furthermore, we discuss important caveats...

  14. Structural Diversification of Lyngbyatoxin A by Host-Dependent Heterologous Expression of the tleABC Biosynthetic Gene Cluster.

    Science.gov (United States)

    Zhang, Lihan; Hoshino, Shotaro; Awakawa, Takayoshi; Wakimoto, Toshiyuki; Abe, Ikuro

    2016-08-03

    Natural products have enormous structural diversity, yet little is known about how such diversity is achieved in nature. Here we report the structural diversification of a cyanotoxin-lyngbyatoxin A-and its biosynthetic intermediates by heterologous expression of the Streptomyces-derived tleABC biosynthetic gene cluster in three different Streptomyces hosts: S. lividans, S. albus, and S. avermitilis. Notably, the isolated lyngbyatoxin derivatives, including four new natural products, were biosynthesized by crosstalk between the heterologous tleABC gene cluster and the endogenous host enzymes. The simple strategy described here has expanded the structural diversity of lyngbyatoxin A and its biosynthetic intermediates, and provides opportunities for investigation of the currently underestimated hidden biosynthetic crosstalk. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Identification and analysis of the paulomycin biosynthetic gene cluster and titer improvement of the paulomycins in Streptomyces paulus NRRL 8115.

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    Jine Li

    Full Text Available The paulomycins are a group of glycosylated compounds featuring a unique paulic acid moiety. To locate their biosynthetic gene clusters, the genomes of two paulomycin producers, Streptomyces paulus NRRL 8115 and Streptomyces sp. YN86, were sequenced. The paulomycin biosynthetic gene clusters were defined by comparative analyses of the two genomes together with the genome of the third paulomycin producer Streptomyces albus J1074. Subsequently, the identity of the paulomycin biosynthetic gene cluster was confirmed by inactivation of two genes involved in biosynthesis of the paulomycose branched chain (pau11 and the ring A moiety (pau18 in Streptomyces paulus NRRL 8115. After determining the gene cluster boundaries, a convergent biosynthetic model was proposed for paulomycin based on the deduced functions of the pau genes. Finally, a paulomycin high-producing strain was constructed by expressing an activator-encoding gene (pau13 in S. paulus, setting the stage for future investigations.

  16. Homologous gene targeting of a carotenoids biosynthetic gene in Rhodosporidium toruloides by Agrobacterium-mediated transformation.

    Science.gov (United States)

    Sun, Wenyi; Yang, Xiaobing; Wang, Xueying; Lin, Xinping; Wang, Yanan; Zhang, Sufang; Luan, Yushi; Zhao, Zongbao K

    2017-07-01

    To target a carotenoid biosynthetic gene in the oleaginous yeast Rhodosporidium toruloides by using the Agrobacterium-mediated transformation (AMT) method. The RHTO_04602 locus of R. toruloides NP11, previously assigned to code the carotenoid biosynthetic gene CRTI, was amplified from genomic DNA and cloned into the binary plasmid pZPK-mcs, resulting in pZPK-CRT. A HYG-expression cassette was inserted into the CRTI sequence of pZPK-CRT by utilizing the restriction-free clone strategy. The resulted plasmid was used to transform R. toruloides cells according to the AMT method, leading to a few white transformants. Sequencing analysis of those transformants confirmed homologous recombination and insertional inactivation of CRTI. When the white variants were transformed with a CRTI-expression cassette, cells became red and produced carotenoids as did the wild-type strain NP11. Successful homologous targeting of the CrtI locus confirmed the function of RHTO_04602 in carotenoids biosynthesis in R. toruloides. It provided valuable information for metabolic engineering of this non-model yeast species.

  17. [Construction of Corynebacterium crenatum AS 1.542 δ argR and analysis of transcriptional levels of the related genes of arginine biosynthetic pathway].

    Science.gov (United States)

    Chen, Xuelan; Tang, Li; Jiao, Haitao; Xu, Feng; Xiong, Yonghua

    2013-01-04

    ArgR, coded by the argR gene from Corynebacterium crenatum AS 1.542, acts as a negative regulator in arginine biosynthetic pathway. However, the effect of argR on transcriptional levels of the related biosynthetic genes has not been reported. Here, we constructed a deletion mutant of argR gene: C. crenatum AS 1.542 Delta argR using marker-less knockout technology, and compared the changes of transcriptional levels of the arginine biosynthetic genes between the mutant strain and the wild-type strain. We used marker-less knockout technology to construct C. crenatum AS 1.542 Delta argR and analyzed the changes of the relate genes at the transcriptional level using real-time fluorescence quantitative PCR. C. crenatum AS 1.542 Delta argR was successfully obtained and the transcriptional level of arginine biosynthetic genes in this mutant increased significantly with an average of about 162.1 folds. The arginine biosynthetic genes in C. crenatum are clearly controlled by the negative regulator ArgR. However, the deletion of this regulator does not result in a clear change in arginine production in the bacteria.

  18. Evolution and Diversity of Biosynthetic Gene Clusters in Fusarium

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    Koen Hoogendoorn

    2018-06-01

    Full Text Available Plant pathogenic fungi in the Fusarium genus cause severe damage to crops, resulting in great financial losses and health hazards. Specialized metabolites synthesized by these fungi are known to play key roles in the infection process, and to provide survival advantages inside and outside the host. However, systematic studies of the evolution of specialized metabolite-coding potential across Fusarium have been scarce. Here, we apply a combination of bioinformatic approaches to identify biosynthetic gene clusters (BGCs across publicly available genomes from Fusarium, to group them into annotated families and to study gain/loss events of BGC families throughout the history of the genus. Comparison with MIBiG reference BGCs allowed assignment of 29 gene cluster families (GCFs to pathways responsible for the production of known compounds, while for 57 GCFs, the molecular products remain unknown. Comparative analysis of BGC repertoires using ancestral state reconstruction raised several new hypotheses on how BGCs contribute to Fusarium pathogenicity or host specificity, sometimes surprisingly so: for example, a gene cluster for the biosynthesis of hexadehydro-astechrome was identified in the genome of the biocontrol strain Fusarium oxysporum Fo47, while being absent in that of the tomato pathogen F. oxysporum f.sp. lycopersici. Several BGCs were also identified on supernumerary chromosomes; heterologous expression of genes for three terpene synthases encoded on the Fusarium poae supernumerary chromosome and subsequent GC/MS analysis showed that these genes are functional and encode enzymes that each are able to synthesize koraiol; this observed functional redundancy supports the hypothesis that localization of copies of BGCs on supernumerary chromosomes provides freedom for evolutionary innovations to occur, while the original function remains conserved. Altogether, this systematic overview of biosynthetic diversity in Fusarium paves the way for

  19. antiSMASH 3.0-a comprehensive resource for the genome mining of biosynthetic gene clusters.

    Science.gov (United States)

    Weber, Tilmann; Blin, Kai; Duddela, Srikanth; Krug, Daniel; Kim, Hyun Uk; Bruccoleri, Robert; Lee, Sang Yup; Fischbach, Michael A; Müller, Rolf; Wohlleben, Wolfgang; Breitling, Rainer; Takano, Eriko; Medema, Marnix H

    2015-07-01

    Microbial secondary metabolism constitutes a rich source of antibiotics, chemotherapeutics, insecticides and other high-value chemicals. Genome mining of gene clusters that encode the biosynthetic pathways for these metabolites has become a key methodology for novel compound discovery. In 2011, we introduced antiSMASH, a web server and stand-alone tool for the automatic genomic identification and analysis of biosynthetic gene clusters, available at http://antismash.secondarymetabolites.org. Here, we present version 3.0 of antiSMASH, which has undergone major improvements. A full integration of the recently published ClusterFinder algorithm now allows using this probabilistic algorithm to detect putative gene clusters of unknown types. Also, a new dereplication variant of the ClusterBlast module now identifies similarities of identified clusters to any of 1172 clusters with known end products. At the enzyme level, active sites of key biosynthetic enzymes are now pinpointed through a curated pattern-matching procedure and Enzyme Commission numbers are assigned to functionally classify all enzyme-coding genes. Additionally, chemical structure prediction has been improved by incorporating polyketide reduction states. Finally, in order for users to be able to organize and analyze multiple antiSMASH outputs in a private setting, a new XML output module allows offline editing of antiSMASH annotations within the Geneious software. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. Insights into secondary metabolism from a global analysis of prokaryotic biosynthetic gene clusters

    NARCIS (Netherlands)

    Cimermancic, P.; Medema, Marnix; Claesen, J.; Kurika, K.; Wieland Brown, L.C.; Mavrommatis, K.; Pati, A.; Godfrey, P.A.; Koehrsen, M.; Clardy, J.; Birren, B. W.; Takano, Eriko; Sali, A.; Linington, R.G.; Fischbach, M.A.

    2014-01-01

    Although biosynthetic gene clusters (BGCs) have been discovered for hundreds of bacterial metabolites, our knowledge of their diversity remains limited. Here, we used a novel algorithm to systematically identify BGCs in the extensive extant microbial sequencing data. Network analysis of the

  1. Diversity of Culturable Thermophilic Actinobacteria in Hot Springs in Tengchong, China and Studies of their Biosynthetic Gene Profiles.

    Science.gov (United States)

    Liu, Lan; Salam, Nimaichand; Jiao, Jian-Yu; Jiang, Hong-Chen; Zhou, En-Min; Yin, Yi-Rui; Ming, Hong; Li, Wen-Jun

    2016-07-01

    The class Actinobacteria has been a goldmine for the discovery of antibiotics and has attracted interest from both academics and industries. However, an absence of novel approaches during the last few decades has limited the discovery of new microbial natural products useful for industries. Scientists are now focusing on the ecological aspects of diverse environments including unexplored or underexplored habitats and extreme environments in the search for new metabolites. This paper reports on the diversity of culturable actinobacteria associated with hot springs located in Tengchong County, Yunnan Province, southwestern China. A total of 58 thermophilic actinobacterial strains were isolated from the samples collected from ten hot springs distributed over three geothermal fields (e.g., Hehua, Rehai, and Ruidian). Phylogenetic positions and their biosynthetic profiles were analyzed by sequencing 16S rRNA gene and three biosynthetic gene clusters (KS domain of PKS-I, KSα domain of PKS-II and A domain of NRPS). On the basis of 16S rRNA gene phylogenetic analysis, the 58 strains were affiliated with 12 actinobacterial genera: Actinomadura Micromonospora, Microbispora, Micrococcus, Nocardiopsis, Nonomuraea, Promicromonospora, Pseudonocardia, Streptomyces, Thermoactinospora, Thermocatellispora, and Verrucosispora, of which the two novel genera Thermoactinospora and Thermocatellisopora were recently described from among these strains. Considering the biosynthetic potential of these actinobacterial strains, 22 were positive for PCR amplification of at least one of the three biosynthetic gene clusters (PKS-I, PKS-II, and NRPS). These actinobacteria were further subjected to antimicrobial assay against five opportunistic human pathogens (Acinetobacter baumannii, Escherichia coli, Micrococcus luteus, Staphylococcus aureus and Streptococcus faecalis). All of the 22 strains that were positive for PCR amplification of at least one of the biosynthetic gene domains exhibited

  2. High GC Content Cas9-Mediated Genome-Editing and Biosynthetic Gene Cluster Activation in Saccharopolyspora erythraea.

    Science.gov (United States)

    Liu, Yong; Wei, Wen-Ping; Ye, Bang-Ce

    2018-05-18

    The overexpression of bacterial secondary metabolite biosynthetic enzymes is the basis for industrial overproducing strains. Genome editing tools can be used to further improve gene expression and yield. Saccharopolyspora erythraea produces erythromycin, which has extensive clinical applications. In this study, the CRISPR-Cas9 system was used to edit genes in the S. erythraea genome. A temperature-sensitive plasmid containing the PermE promoter, to drive Cas9 expression, and the Pj23119 and PkasO promoters, to drive sgRNAs, was designed. Erythromycin esterase, encoded by S. erythraea SACE_1765, inactivates erythromycin by hydrolyzing the macrolactone ring. Sequencing and qRT-PCR confirmed that reporter genes were successfully inserted into the SACE_1765 gene. Deletion of SACE_1765 in a high-producing strain resulted in a 12.7% increase in erythromycin levels. Subsequent PermE- egfp knock-in at the SACE_0712 locus resulted in an 80.3% increase in erythromycin production compared with that of wild type. Further investigation showed that PermE promoter knock-in activated the erythromycin biosynthetic gene clusters at the SACE_0712 locus. Additionally, deletion of indA (SACE_1229) using dual sgRNA targeting without markers increased the editing efficiency to 65%. In summary, we have successfully applied Cas9-based genome editing to a bacterial strain, S. erythraea, with a high GC content. This system has potential application for both genome-editing and biosynthetic gene cluster activation in Actinobacteria.

  3. New insights into the organization and regulation of trichothecene biosynthetic genes in Trichoderma

    Science.gov (United States)

    Collectively, species of the genus Trichoderma can produce numerous structurally diverse secondary metabolites (SM). This ability is conferred by the presence of SM biosynthetic gene clusters in their genomes. Species of Trichoderma in the Brevicompactum clade are able to produce trichothecenes, a f...

  4. antiSMASH 3.0—a comprehensive resource for the genome mining of biosynthetic gene clusters

    DEFF Research Database (Denmark)

    Weber, Tilmann; Blin, Kai; Duddela, Srikanth

    2015-01-01

    Microbial secondary metabolism constitutes a rich source of antibiotics, chemotherapeutics, insecticides and other high-value chemicals. Genome mining of gene clusters that encode the biosynthetic pathways for these metabolites has become a key methodology for novel compound discovery. In 2011, we...... introduced antiSMASH, a web server and stand-alone tool for the automatic genomic identification and analysis of biosynthetic gene clusters, available at http://antismash.secondarymetabolites.org. Here, we present version 3.0 of antiSMASH, which has undergone major improvements. A full integration...... of the recently published ClusterFinder algorithm now allows using this probabilistic algorithm to detect putative gene clusters of unknown types. Also, a new dereplication variant of the ClusterBlast module now identifies similarities of identified clusters to any of 1172 clusters with known end products...

  5. Heterologous stable expression of terpenoid biosynthetic genes using the moss Physcomitrella patens

    DEFF Research Database (Denmark)

    Bach, Søren Spanner; King, Brian Christopher; Zhan, Xin

    2014-01-01

    Heterologous and stable expression of genes encoding terpenoid biosynthetic enzymes in planta is an important tool for functional characterization and is an attractive alternative to expression in microbial hosts for biotechnological production. Despite improvements to the procedure, such as stre...

  6. Molecular characterization of tocopherol biosynthetic genes in sweetpotato that respond to stress and activate the tocopherol production in tobacco.

    Science.gov (United States)

    Ji, Chang Yoon; Kim, Yun-Hee; Kim, Ho Soo; Ke, Qingbo; Kim, Gun-Woo; Park, Sung-Chul; Lee, Haeng-Soon; Jeong, Jae Cheol; Kwak, Sang-Soo

    2016-09-01

    Tocopherol (vitamin E) is a chloroplast lipid that is presumed to be involved in the plant response to oxidative stress. In this study, we isolated and characterized five tocopherol biosynthetic genes from sweetpotato (Ipomoea batatas [L.] Lam) plants, including genes encoding 4-hydroxyphenylpyruvate dioxygenase (IbHPPD), homogentisate phytyltransferase (IbHPT), 2-methyl-6-phytylbenzoquinol methyltransferase (IbMPBQ MT), tocopherol cyclase (IbTC) and γ-tocopherol methyltransferase (IbTMT). Fluorescence microscope analysis indicated that four proteins localized into the chloroplast, whereas IbHPPD observed in the nuclear. Quantitative RT-PCR analysis revealed that the expression patterns of the five tocopherol biosynthetic genes varied in different plant tissues and under different stress conditions. All five genes were highly expressed in leaf tissues, whereas IbHPPD and IbHPT were highly expressed in the thick roots. The expression patterns of these five genes significantly differed in response to PEG, NaCl and H2O2-mediated oxidative stress. IbHPPD was strongly induced following PEG and H2O2 treatment and IbHPT was strongly induced following PEG treatment, whereas IbMPBQ MT and IbTC were highly expressed following NaCl treatment. Upon infection of the bacterial pathogen Pectobacterium chrysanthemi, the expression of IbHPPD increased sharply in sweetpotato leaves, whereas the expression of the other genes was reduced or unchanged. Additionally, transient expression of the five tocopherol biosynthetic genes in tobacco (Nicotiana bentamiana) leaves resulted in increased transcript levels of the transgenes expressions and tocopherol production. Therefore, our results suggested that the five tocopherol biosynthetic genes of sweetpotato play roles in the stress defense response as transcriptional regulators of the tocopherol production. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. Expression of Terpenoid Biosynthetic Genes and Accumulation of Chemical Constituents in Valeriana fauriei

    Directory of Open Access Journals (Sweden)

    Yun Ji Park

    2016-05-01

    Full Text Available Valeriana fauriei (V. fauriei, which emits a characteristic and unpleasant odor, is important in traditional medicine. In this study, the expression of terpenoid biosynthetic genes was investigated in different organs that were also screened for volatile compounds including valerenic acid and its derivatives. Specific expression patterns from different parts of V. fauriei were observed using quantitative real-time PCR (qRT-PCR. The highest transcript levels of biosynthetic genes involved in mevalonic acid (MVA and methylerythritol phosphate (MEP production were found in the stem. Although the amounts of volatile compounds were varied by organ, most of the volatile terpenoids were accumulated in the root. Gas chromatography mass spectrometry (GC-MS analysis identified 128 volatile compounds, which represented 65.33% to 95.66% of total volatiles. Certain compounds were only found in specific organs. For example, isovalerenic acid and valerenic acid and its derivatives were restricted to the root. Organs with high transcript levels did not necessarily have high levels of the corresponding chemical constituents. According to these results, we hypothesize that translocation may occur between different organs in V. fauriei.

  8. Multiplex PCR analysis of fumonisin biosynthetic genes in fumonisin-nonproducing Aspergillus niger and A. awamori strains

    Science.gov (United States)

    In order to determine the genetic basis for loss of fumonisin B¬2 (FB2) biosynthesis in FB2 non-producing A. niger strains, we developed multiplex PCR primer sets to amplify fragments of eight fumonisin biosynthetic pathway (fum) genes. Fragments of all eight fum genes were amplified in FB2-produci...

  9. Expression of phenazine biosynthetic genes during the arbuscular mycorrhizal symbiosis of Glomus intraradices

    Directory of Open Access Journals (Sweden)

    Dionicia Gloria León-Martínez

    2012-06-01

    Full Text Available To explore the molecular mechanisms that prevail during the establishment of the arbuscular mycorrhiza symbiosis involving the genus Glomus, we transcriptionally analysed spores of Glomus intraradices BE3 during early hyphal growth. Among 458 transcripts initially identified as being expressed at presymbiotic stages, 20% of sequences had homology to previously characterized eukaryotic genes, 30% were homologous to fungal coding sequences, and 9% showed homology to previously characterized bacterial genes. Among them, GintPbr1a encodes a homolog to Phenazine Biosynthesis Regulator (Pbr of Burkholderia cenocepacia, an pleiotropic regulatory protein that activates phenazine production through transcriptional activation of the protein D isochorismatase biosynthetic enzyme phzD (Ramos et al., 2010. Whereas GintPbr1a is expressed during the presymbiotic phase, the G. intraradices BE3 homolog of phzD (BGintphzD is transcriptionally active at the time of the establishment of the arbuscular mycorrhizal symbiosis. DNA from isolated bacterial cultures found in spores of G. intraradices BE3 confirmed that both BGintPbr1a and BGintphzD are present in the genome of its potential endosymbionts. Taken together, our results indicate that spores of G. intraradices BE3 express bacterial phenazine biosynthetic genes at the onset of the fungal-plant symbiotic interaction.

  10. The Cremeomycin Biosynthetic Gene Cluster Encodes a Pathway for Diazo Formation.

    Science.gov (United States)

    Waldman, Abraham J; Pechersky, Yakov; Wang, Peng; Wang, Jennifer X; Balskus, Emily P

    2015-10-12

    Diazo groups are found in a range of natural products that possess potent biological activities. Despite longstanding interest in these metabolites, diazo group biosynthesis is not well understood, in part because of difficulties in identifying specific genes linked to diazo formation. Here we describe the discovery of the gene cluster that produces the o-diazoquinone natural product cremeomycin and its heterologous expression in Streptomyces lividans. We used stable isotope feeding experiments and in vitro characterization of biosynthetic enzymes to decipher the order of events in this pathway and establish that diazo construction involves late-stage N-N bond formation. This work represents the first successful production of a diazo-containing metabolite in a heterologous host, experimentally linking a set of genes with diazo formation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. IMG-ABC: A Knowledge Base To Fuel Discovery of Biosynthetic Gene Clusters and Novel Secondary Metabolites.

    Science.gov (United States)

    Hadjithomas, Michalis; Chen, I-Min Amy; Chu, Ken; Ratner, Anna; Palaniappan, Krishna; Szeto, Ernest; Huang, Jinghua; Reddy, T B K; Cimermančič, Peter; Fischbach, Michael A; Ivanova, Natalia N; Markowitz, Victor M; Kyrpides, Nikos C; Pati, Amrita

    2015-07-14

    In the discovery of secondary metabolites, analysis of sequence data is a promising exploration path that remains largely underutilized due to the lack of computational platforms that enable such a systematic approach on a large scale. In this work, we present IMG-ABC (https://img.jgi.doe.gov/abc), an atlas of biosynthetic gene clusters within the Integrated Microbial Genomes (IMG) system, which is aimed at harnessing the power of "big" genomic data for discovering small molecules. IMG-ABC relies on IMG's comprehensive integrated structural and functional genomic data for the analysis of biosynthetic gene clusters (BCs) and associated secondary metabolites (SMs). SMs and BCs serve as the two main classes of objects in IMG-ABC, each with a rich collection of attributes. A unique feature of IMG-ABC is the incorporation of both experimentally validated and computationally predicted BCs in genomes as well as metagenomes, thus identifying BCs in uncultured populations and rare taxa. We demonstrate the strength of IMG-ABC's focused integrated analysis tools in enabling the exploration of microbial secondary metabolism on a global scale, through the discovery of phenazine-producing clusters for the first time in Alphaproteobacteria. IMG-ABC strives to fill the long-existent void of resources for computational exploration of the secondary metabolism universe; its underlying scalable framework enables traversal of uncovered phylogenetic and chemical structure space, serving as a doorway to a new era in the discovery of novel molecules. IMG-ABC is the largest publicly available database of predicted and experimental biosynthetic gene clusters and the secondary metabolites they produce. The system also includes powerful search and analysis tools that are integrated with IMG's extensive genomic/metagenomic data and analysis tool kits. As new research on biosynthetic gene clusters and secondary metabolites is published and more genomes are sequenced, IMG-ABC will continue to

  12. The Arabidopsis histone chaperone FACT is required for stress-induced expression of anthocyanin biosynthetic genes.

    Science.gov (United States)

    Pfab, Alexander; Breindl, Matthias; Grasser, Klaus D

    2018-03-01

    The histone chaperone FACT is involved in the expression of genes encoding anthocyanin biosynthetic enzymes also upon induction by moderate high-light and therefore contributes to the stress-induced plant pigmentation. The histone chaperone FACT consists of the SSRP1 and SPT16 proteins and associates with transcribing RNAPII (RNAPII) along the transcribed region of genes. FACT can promote transcriptional elongation by destabilising nucleosomes in the path of RNA polymerase II, thereby facilitating efficient transcription of chromatin templates. Transcript profiling of Arabidopsis plants depleted in SSRP1 or SPT16 demonstrates that only a small subset of genes is differentially expressed relative to wild type. The majority of these genes is either up- or down-regulated in both the ssrp1 and spt16 plants. Among the down-regulated genes, those encoding enzymes of the biosynthetic pathway of the plant secondary metabolites termed anthocyanins (but not regulators of the pathway) are overrepresented. Upon exposure to moderate high-light stress several of these genes are up-regulated to a lesser extent in ssrp1/spt16 compared to wild type plants, and accordingly the mutant plants accumulate lower amounts of anthocyanin pigments. Moreover, the expression of SSRP1 and SPT16 is induced under these conditions. Therefore, our findings indicate that FACT is a novel factor required for the accumulation of anthocyanins in response to light-induction.

  13. Draft genome sequence of Streptomyces coelicoflavus ZG0656 reveals the putative biosynthetic gene cluster of acarviostatin family α-amylase inhibitors.

    Science.gov (United States)

    Guo, X; Geng, P; Bai, F; Bai, G; Sun, T; Li, X; Shi, L; Zhong, Q

    2012-08-01

    The aims of this study are to obtain the draft genome sequence of Streptomyces coelicoflavus ZG0656, which produces novel acarviostatin family α-amylase inhibitors, and then to reveal the putative acarviostatin-related gene cluster and the biosynthetic pathway. The draft genome sequence of S. coelicoflavus ZG0656 was generated using a shotgun approach employing a combination of 454 and Solexa sequencing technologies. Genome analysis revealed a putative gene cluster for acarviostatin biosynthesis, termed sct-cluster. The cluster contains 13 acarviostatin synthetic genes, six transporter genes, four starch degrading or transglycosylation enzyme genes and two regulator genes. On the basis of bioinformatic analysis, we proposed a putative biosynthetic pathway of acarviostatins. The intracellular steps produce a structural core, acarviostatin I00-7-P, and the extracellular assemblies lead to diverse acarviostatin end products. The draft genome sequence of S. coelicoflavus ZG0656 revealed the putative biosynthetic gene cluster of acarviostatins and a putative pathway of acarviostatin production. To our knowledge, S. coelicoflavus ZG0656 is the first strain in this species for which a genome sequence has been reported. The analysis of sct-cluster provided important insights into the biosynthesis of acarviostatins. This work will be a platform for producing novel variants and yield improvement. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

  14. Identification of the chelocardin biosynthetic gene cluster from Amycolatopsis sulphurea: a platform for producing novel tetracycline antibiotics.

    Science.gov (United States)

    Lukežič, Tadeja; Lešnik, Urška; Podgoršek, Ajda; Horvat, Jaka; Polak, Tomaž; Šala, Martin; Jenko, Branko; Raspor, Peter; Herron, Paul R; Hunter, Iain S; Petković, Hrvoje

    2013-12-01

    Tetracyclines (TCs) are medically important antibiotics from the polyketide family of natural products. Chelocardin (CHD), produced by Amycolatopsis sulphurea, is a broad-spectrum tetracyclic antibiotic with potent bacteriolytic activity against a number of Gram-positive and Gram-negative multi-resistant pathogens. CHD has an unknown mode of action that is different from TCs. It has some structural features that define it as 'atypical' and, notably, is active against tetracycline-resistant pathogens. Identification and characterization of the chelocardin biosynthetic gene cluster from A. sulphurea revealed 18 putative open reading frames including a type II polyketide synthase. Compared to typical TCs, the chd cluster contains a number of features that relate to its classification as 'atypical': an additional gene for a putative two-component cyclase/aromatase that may be responsible for the different aromatization pattern, a gene for a putative aminotransferase for C-4 with the opposite stereochemistry to TCs and a gene for a putative C-9 methylase that is a unique feature of this biosynthetic cluster within the TCs. Collectively, these enzymes deliver a molecule with different aromatization of ring C that results in an unusual planar structure of the TC backbone. This is a likely contributor to its different mode of action. In addition CHD biosynthesis is primed with acetate, unlike the TCs, which are primed with malonamate, and offers a biosynthetic engineering platform that represents a unique opportunity for efficient generation of novel tetracyclic backbones using combinatorial biosynthesis.

  15. Genetic interrelations in the actinomycin biosynthetic gene clusters of Streptomyces antibioticus IMRU 3720 and Streptomyces chrysomallus ATCC11523, producers of actinomycin X and actinomycin C

    Directory of Open Access Journals (Sweden)

    Crnovčić I

    2017-04-01

    Full Text Available Ivana Crnovčić,1 Christian Rückert,2 Siamak Semsary,1 Manuel Lang,1 Jörn Kalinowski,2 Ullrich Keller1 1Institut für Chemie, Technische Universität Berlin, Berlin-Charlottenburg, 2Technology Platform Genomics, Center for Biotechnology, Bielefeld University, Bielefeld, Germany Abstract: Sequencing the actinomycin (acm biosynthetic gene cluster of Streptomyces antibioticus IMRU 3720, which produces actinomycin X (Acm X, revealed 20 genes organized into a highly similar framework as in the bi-armed acm C biosynthetic gene cluster of Streptomyces chrysomallus but without an attached additional extra arm of orthologues as in the latter. Curiously, the extra arm of the S. chrysomallus gene cluster turned out to perfectly match the single arm of the S. antibioticus gene cluster in the same order of orthologues including the the presence of two pseudogenes, scacmM and scacmN, encoding a cytochrome P450 and its ferredoxin, respectively. Orthologues of the latter genes were both missing in the principal arm of the S. chrysomallus acm C gene cluster. All orthologues of the extra arm showed a G +C-contents different from that of their counterparts in the principal arm. Moreover, the similarities of translation products from the extra arm were all higher to the corresponding translation products of orthologue genes from the S. antibioticus acm X gene cluster than to those encoded by the principal arm of their own gene cluster. This suggests that the duplicated structure of the S. chrysomallus acm C biosynthetic gene cluster evolved from previous fusion between two one-armed acm gene clusters each from a different genetic background. However, while scacmM and scacmN in the extra arm of the S. chrysomallus acm C gene cluster are mutated and therefore are non-functional, their orthologues saacmM and saacmN in the S. antibioticus acm C gene cluster show no defects seemingly encoding active enzymes with functions specific for Acm X biosynthesis. Both acm

  16. Characterization of the fumonisin B2 biosynthetic gene cluster in Aspergillus niger and A. awamori.

    Science.gov (United States)

    Aspergillus niger and A. awamori strains isolated from grapes cultivated in Mediterranean basin were examined for fumonisin B2 (FB2) production and presence/absence of sequences within the fumonisin biosynthetic gene (fum) cluster. Presence of 13 regions in the fum cluster was evaluated by PCR assay...

  17. Genome mining of the sordarin biosynthetic gene cluster from Sordaria araneosa Cain ATCC 36386: characterization of cycloaraneosene synthase and GDP-6-deoxyaltrose transferase.

    Science.gov (United States)

    Kudo, Fumitaka; Matsuura, Yasunori; Hayashi, Takaaki; Fukushima, Masayuki; Eguchi, Tadashi

    2016-07-01

    Sordarin is a glycoside antibiotic with a unique tetracyclic diterpene aglycone structure called sordaricin. To understand its intriguing biosynthetic pathway that may include a Diels-Alder-type [4+2]cycloaddition, genome mining of the gene cluster from the draft genome sequence of the producer strain, Sordaria araneosa Cain ATCC 36386, was carried out. A contiguous 67 kb gene cluster consisting of 20 open reading frames encoding a putative diterpene cyclase, a glycosyltransferase, a type I polyketide synthase, and six cytochrome P450 monooxygenases were identified. In vitro enzymatic analysis of the putative diterpene cyclase SdnA showed that it catalyzes the transformation of geranylgeranyl diphosphate to cycloaraneosene, a known biosynthetic intermediate of sordarin. Furthermore, a putative glycosyltransferase SdnJ was found to catalyze the glycosylation of sordaricin in the presence of GDP-6-deoxy-d-altrose to give 4'-O-demethylsordarin. These results suggest that the identified sdn gene cluster is responsible for the biosynthesis of sordarin. Based on the isolated potential biosynthetic intermediates and bioinformatics analysis, a plausible biosynthetic pathway for sordarin is proposed.

  18. Expression of carotenoid biosynthetic pathway genes and changes in carotenoids during ripening in tomato (Lycopersicon esculentum).

    Science.gov (United States)

    Namitha, Kanakapura Krishnamurthy; Archana, Surya Narayana; Negi, Pradeep Singh

    2011-04-01

    To study the expression pattern of carotenoid biosynthetic pathway genes, changes in their expression at different stages of maturity in tomato fruit (cv. Arka Ahuti) were investigated. The genes regulating carotenoid production were quantified by a dot blot method using a DIG (dioxigenin) labelling and detection kit. The results revealed that there was an increase in the levels of upstream genes of the carotenoid biosynthetic pathway such as 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), 4-hydroxy-3-methyl-but-2-enyl diphosphate reductase (Lyt B), phytoene synthase (PSY), phytoene desaturase (PDS) and ζ-carotene desaturase (ZDS) by 2-4 fold at the breaker stage as compared to leaf. The lycopene and β-carotene content was analyzed by HPLC at different stages of maturity. The lycopene (15.33 ± 0.24 mg per 100 g) and β-carotene (10.37 ± 0.46 mg per 100 g) content were found to be highest at 5 days post-breaker and 10 days post-breaker stage, respectively. The lycopene accumulation pattern also coincided with the color values at different stages of maturity. These studies may provide insight into devising gene-based strategies for enhancing carotenoid accumulation in tomato fruits.

  19. Bioengineering natural product biosynthetic pathways for therapeutic applications.

    Science.gov (United States)

    Wu, Ming-Cheng; Law, Brian; Wilkinson, Barrie; Micklefield, Jason

    2012-12-01

    With the advent of next-generation DNA sequencing technologies, the number of microbial genome sequences has increased dramatically, revealing a vast array of new biosynthetic gene clusters. Genomics data provide a tremendous opportunity to discover new natural products, and also to guide the bioengineering of new and existing natural product scaffolds for therapeutic applications. Notably, it is apparent that the vast majority of biosynthetic gene clusters are either silent or produce very low quantities of the corresponding natural products. It is imperative therefore to devise methods for activating unproductive biosynthetic pathways to provide the quantities of natural products needed for further development. Moreover, on the basis of our expanding mechanistic and structural knowledge of biosynthetic assembly-line enzymes, new strategies for re-programming biosynthetic pathways have emerged, resulting in focused libraries of modified products with potentially improved biological properties. In this review we will focus on the latest bioengineering approaches that have been utilised to optimise yields and increase the structural diversity of natural product scaffolds for future clinical applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. SCS3 and YFT2 link transcription of phospholipid biosynthetic genes to ER stress and the UPR.

    Directory of Open Access Journals (Sweden)

    Robyn D Moir

    2012-08-01

    Full Text Available The ability to store nutrients in lipid droplets (LDs is an ancient function that provides the primary source of metabolic energy during periods of nutrient insufficiency and between meals. The Fat storage-Inducing Transmembrane (FIT proteins are conserved ER-resident proteins that facilitate fat storage by partitioning energy-rich triglycerides into LDs. FIT2, the ancient ortholog of the FIT gene family first identified in mammals has two homologs in Saccharomyces cerevisiae (SCS3 and YFT2 and other fungi of the Saccharomycotina lineage. Despite the coevolution of these genes for more than 170 million years and their divergence from higher eukaryotes, SCS3, YFT2, and the human FIT2 gene retain some common functions: expression of the yeast genes in a human embryonic kidney cell line promotes LD formation, and expression of human FIT2 in yeast rescues the inositol auxotrophy and chemical and genetic phenotypes of strains lacking SCS3. To better understand the function of SCS3 and YFT2, we investigated the chemical sensitivities of strains deleted for either or both genes and identified synthetic genetic interactions against the viable yeast gene-deletion collection. We show that SCS3 and YFT2 have shared and unique functions that connect major biosynthetic processes critical for cell growth. These include lipid metabolism, vesicular trafficking, transcription of phospholipid biosynthetic genes, and protein synthesis. The genetic data indicate that optimal strain fitness requires a balance between phospholipid synthesis and protein synthesis and that deletion of SCS3 and YFT2 impacts a regulatory mechanism that coordinates these processes. Part of this mechanism involves a role for SCS3 in communicating changes in the ER (e.g. due to low inositol to Opi1-regulated transcription of phospholipid biosynthetic genes. We conclude that SCS3 and YFT2 are required for normal ER membrane biosynthesis in response to perturbations in lipid metabolism and ER

  1. Cloning of the staurosporine biosynthetic gene cluster from Streptomyces sp. TP-A0274 and its heterologous expression in Streptomyces lividans.

    Science.gov (United States)

    Onaka, Hiroyasu; Taniguchi, Shin-ichi; Igarashi, Yasuhiro; Furumai, Tamotsu

    2002-12-01

    Staurosporine is a representative member of indolocarbazole antibiotics. The entire staurosporine biosynthetic and regulatory gene cluster spanning 20-kb was cloned from Streptomyces sp. TP-A0274 and sequenced. The gene cluster consists of 14 ORFs and the amino acid sequence homology search revealed that it contains three genes, staO, staD, and staP, coding for the enzymes involved in the indolocarbazole aglycone biosynthesis, two genes, staG and staN, for the bond formation between the aglycone and deoxysugar, eight genes, staA, staB, staE, staJ, staI, staK, staMA, and staMB, for the deoxysugar biosynthesis and one gene, staR is a transcriptional regulator. Heterologous gene expression of a 38-kb fragment containing a complete set of the biosynthetic genes for staurosporine cloned into pTOYAMAcos confirmed its role in staurosporine biosynthesis. Moreover, the distribution of the gene for chromopyrrolic acid synthase, the key enzyme for the biosynthesis of indolocarbazole aglycone, in actinomycetes was investigated, and rebD homologs were shown to exist only in the strains producing indolocarbazole antibiotics.

  2. IMG-ABC: new features for bacterial secondary metabolism analysis and targeted biosynthetic gene cluster discovery in thousands of microbial genomes.

    Science.gov (United States)

    Hadjithomas, Michalis; Chen, I-Min A; Chu, Ken; Huang, Jinghua; Ratner, Anna; Palaniappan, Krishna; Andersen, Evan; Markowitz, Victor; Kyrpides, Nikos C; Ivanova, Natalia N

    2017-01-04

    Secondary metabolites produced by microbes have diverse biological functions, which makes them a great potential source of biotechnologically relevant compounds with antimicrobial, anti-cancer and other activities. The proteins needed to synthesize these natural products are often encoded by clusters of co-located genes called biosynthetic gene clusters (BCs). In order to advance the exploration of microbial secondary metabolism, we developed the largest publically available database of experimentally verified and predicted BCs, the Integrated Microbial Genomes Atlas of Biosynthetic gene Clusters (IMG-ABC) (https://img.jgi.doe.gov/abc/). Here, we describe an update of IMG-ABC, which includes ClusterScout, a tool for targeted identification of custom biosynthetic gene clusters across 40 000 isolate microbial genomes, and a new search capability to query more than 700 000 BCs from isolate genomes for clusters with similar Pfam composition. Additional features enable fast exploration and analysis of BCs through two new interactive visualization features, a BC function heatmap and a BC similarity network graph. These new tools and features add to the value of IMG-ABC's vast body of BC data, facilitating their in-depth analysis and accelerating secondary metabolite discovery. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. Flg22-Triggered Immunity Negatively Regulates Key BR Biosynthetic Genes.

    Science.gov (United States)

    Jiménez-Góngora, Tamara; Kim, Seong-Ki; Lozano-Durán, Rosa; Zipfel, Cyril

    2015-01-01

    In plants, activation of growth and activation of immunity are opposing processes that define a trade-off. In the past few years, the growth-promoting hormones brassinosteroids (BR) have emerged as negative regulators of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), promoting growth at the expense of defense. The crosstalk between BR and PTI signaling was described as negative and unidirectional, since activation of PTI does not affect several analyzed steps in the BR signaling pathway. In this work, we describe that activation of PTI by the bacterial PAMP flg22 results in the reduced expression of BR biosynthetic genes. This effect does not require BR perception or signaling, and occurs within 15 min of flg22 treatment. Since the described PTI-induced repression of gene expression may result in a reduction in BR biosynthesis, the crosstalk between PTI and BR could actually be negative and bidirectional, a possibility that should be taken into account when considering the interaction between these two pathways.

  4. IMG-ABC: An Atlas of Biosynthetic Gene Clusters to Fuel the Discovery of Novel Secondary Metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Chen, I-Min; Chu, Ken; Ratner, Anna; Palaniappan, Krishna; Huang, Jinghua; Reddy, T. B.K.; Cimermancic, Peter; Fischbach, Michael; Ivanova, Natalia; Markowitz, Victor; Kyrpides, Nikos; Pati, Amrita

    2014-10-28

    In the discovery of secondary metabolites (SMs), large-scale analysis of sequence data is a promising exploration path that remains largely underutilized due to the lack of relevant computational resources. We present IMG-ABC (https://img.jgi.doe.gov/abc/) -- An Atlas of Biosynthetic gene Clusters within the Integrated Microbial Genomes (IMG) system1. IMG-ABC is a rich repository of both validated and predicted biosynthetic clusters (BCs) in cultured isolates, single-cells and metagenomes linked with the SM chemicals they produce and enhanced with focused analysis tools within IMG. The underlying scalable framework enables traversal of phylogenetic dark matter and chemical structure space -- serving as a doorway to a new era in the discovery of novel molecules.

  5. Higher transcription levels in ascorbic acid biosynthetic and recycling genes were associated with higher ascorbic acid accumulation in blueberry.

    Science.gov (United States)

    Liu, Fenghong; Wang, Lei; Gu, Liang; Zhao, Wei; Su, Hongyan; Cheng, Xianhao

    2015-12-01

    In our preliminary study, the ripe fruits of two highbush blueberry (Vaccinium corymbosum L.) cultivars, cv 'Berkeley' and cv 'Bluecrop', were found to contain different levels of ascorbic acid. However, factors responsible for these differences are still unknown. In the present study, ascorbic acid content in fruits was compared with expression profiles of ascorbic acid biosynthetic and recycling genes between 'Bluecrop' and 'Berkeley' cultivars. The results indicated that the l-galactose pathway was the predominant route of ascorbic acid biosynthesis in blueberry fruits. Moreover, higher expression levels of the ascorbic acid biosynthetic genes GME, GGP, and GLDH, as well as the recycling genes MDHAR and DHAR, were associated with higher ascorbic acid content in 'Bluecrop' compared with 'Berkeley', which indicated that a higher efficiency ascorbic acid biosynthesis and regeneration was likely to be responsible for the higher ascorbic acid accumulation in 'Bluecrop'. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. ATAF1 transcription factor directly regulates abscisic acid biosynthetic gene NCED3 in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Jensen, Michael Krogh; Lindemose, Søren; De Masi, Federico

    2013-01-01

    ATAF1, an Arabidopsis thaliana NAC transcription factor, plays important roles in plant adaptation to environmental stress and development. To search for ATAF1 target genes, we used protein binding microarrays and chromatin-immunoprecipitation (ChIP). This identified T[A,C,G]CGT[A,G] and TT[A,C,G...... abscisic acid (ABA) phytohormone biosynthetic gene NCED3. ChIP-qPCR and expression analysis showed that ATAF1 binding to the NCED3 promoter correlated with increased NCED3 expression and ABA hormone levels. These results indicate that ATAF1 regulates ABA biosynthesis....

  7. Genetic interrelations in the actinomycin biosynthetic gene clusters of Streptomyces antibioticus IMRU 3720 and Streptomyces chrysomallus ATCC11523, producers of actinomycin X and actinomycin C

    Science.gov (United States)

    Crnovčić, Ivana; Rückert, Christian; Semsary, Siamak; Lang, Manuel; Kalinowski, Jörn; Keller, Ullrich

    2017-01-01

    Sequencing the actinomycin (acm) biosynthetic gene cluster of Streptomyces antibioticus IMRU 3720, which produces actinomycin X (Acm X), revealed 20 genes organized into a highly similar framework as in the bi-armed acm C biosynthetic gene cluster of Streptomyces chrysomallus but without an attached additional extra arm of orthologues as in the latter. Curiously, the extra arm of the S. chrysomallus gene cluster turned out to perfectly match the single arm of the S. antibioticus gene cluster in the same order of orthologues including the the presence of two pseudogenes, scacmM and scacmN, encoding a cytochrome P450 and its ferredoxin, respectively. Orthologues of the latter genes were both missing in the principal arm of the S. chrysomallus acm C gene cluster. All orthologues of the extra arm showed a G +C-contents different from that of their counterparts in the principal arm. Moreover, the similarities of translation products from the extra arm were all higher to the corresponding translation products of orthologue genes from the S. antibioticus acm X gene cluster than to those encoded by the principal arm of their own gene cluster. This suggests that the duplicated structure of the S. chrysomallus acm C biosynthetic gene cluster evolved from previous fusion between two one-armed acm gene clusters each from a different genetic background. However, while scacmM and scacmN in the extra arm of the S. chrysomallus acm C gene cluster are mutated and therefore are non-functional, their orthologues saacmM and saacmN in the S. antibioticus acm C gene cluster show no defects seemingly encoding active enzymes with functions specific for Acm X biosynthesis. Both acm biosynthetic gene clusters lack a kynurenine-3-monooxygenase gene necessary for biosynthesis of 3-hydroxy-4-methylanthranilic acid, the building block of the Acm chromophore, which suggests participation of a genome-encoded relevant monooxygenase during Acm biosynthesis in both S. chrysomallus and S

  8. Vanillin biosynthetic pathways in plants.

    Science.gov (United States)

    Kundu, Anish

    2017-06-01

    The present review compiles the up-to-date knowledge on vanillin biosynthesis in plant systems to focus principally on the enzymatic reactions of in planta vanillin biosynthetic pathway and to find out its impact and prospect in future research in this field. Vanillin, a very popular flavouring compound, is widely used throughout the world. The principal natural resource of vanillin is the cured vanilla pods. Due to the high demand of vanillin as a flavouring agent, it is necessary to explore its biosynthetic enzymes and genes, so that improvement in its commercial production can be achieved through metabolic engineering. In spite of significant advancement in elucidating vanillin biosynthetic pathway in the last two decades, no conclusive demonstration had been reported yet for plant system. Several biosynthetic enzymes have been worked upon but divergences in published reports, particularly in characterizing the crucial biochemical steps of vanillin biosynthesis, such as side-chain shortening, methylation, and glucoside formation and have created a space for discussion. Recently, published reviews on vanillin biosynthesis have focused mainly on the biotechnological approaches and bioconversion in microbial systems. This review, however, aims to compile in brief the overall vanillin biosynthetic route and present a comparative as well as comprehensive description of enzymes involved in the pathway in Vanilla planifolia and other plants. Special emphasis has been given on the key enzymatic biochemical reactions that have been investigated extensively. Finally, the present standpoint and future prospects have been highlighted.

  9. Treadmill exercise does not change gene expression of adrenal catecholamine biosynthetic enzymes in chronically stressed rats

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    LJUBICA GAVRILOVIC

    2013-09-01

    Full Text Available ABSTRACT Chronic isolation of adult animals represents a form of psychological stress that produces sympatho-adrenomedullar activation. Exercise training acts as an important modulator of sympatho-adrenomedullary system. This study aimed to investigate physical exercise-related changes in gene expression of catecholamine biosynthetic enzymes (tyrosine hydroxylase, dopamine-ß-hydroxylase and phenylethanolamine N-methyltransferase and cyclic adenosine monophosphate response element-binding (CREB in the adrenal medulla, concentrations of catecholamines and corticosterone (CORT in the plasma and the weight of adrenal glands of chronically psychosocially stressed adult rats exposed daily to 20 min treadmill running for 12 weeks. Also, we examined how additional acute immobilization stress changes the mentioned parameters. Treadmill running did not result in modulation of gene expression of catecholamine synthesizing enzymes and it decreased the level of CREB mRNA in the adrenal medulla of chronically psychosocially stressed adult rats. The potentially negative physiological adaptations after treadmill running were recorded as increased concentrations of catecholamines and decreased morning CORT concentration in the plasma, as well as the adrenal gland hypertrophy of chronically psychosocially stressed rats. The additional acute immobilization stress increases gene expression of catecholamine biosynthetic enzymes in the adrenal medulla, as well as catecholamines and CORT levels in the plasma. Treadmill exercise does not change the activity of sympatho-adrenomedullary system of chronically psychosocially stressed rats.

  10. Biosynthetic Pathways of Ergot Alkaloids

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    Nina Gerhards

    2014-12-01

    Full Text Available Ergot alkaloids are nitrogen-containing natural products belonging to indole alkaloids. The best known producers are fungi of the phylum Ascomycota, e.g., Claviceps, Epichloë, Penicillium and Aspergillus species. According to their structures, ergot alkaloids can be divided into three groups: clavines, lysergic acid amides and peptides (ergopeptines. All of them share the first biosynthetic steps, which lead to the formation of the tetracyclic ergoline ring system (except the simplest, tricyclic compound: chanoclavine. Different modifications on the ergoline ring by specific enzymes result in an abundance of bioactive natural products, which are used as pharmaceutical drugs or precursors thereof. From the 1950s through to recent years, most of the biosynthetic pathways have been elucidated. Gene clusters from several ergot alkaloid producers have been identified by genome mining and the functions of many of those genes have been demonstrated by knock-out experiments or biochemical investigations of the overproduced enzymes.

  11. Phenylpropanoids accumulation in eggplant fruit: characterization of biosynthetic genes and regulation by a MYB transcription factor

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    Teresa eDocimo

    2016-01-01

    Full Text Available Phenylpropanoids are major secondary metabolites in eggplant (Solanum melongena fruits. Chlorogenic acid (CGA accounts for 70 to 90% of total phenolics in flesh tissues, while anthocyanins are mainly present in the fruit skin. As a contribution to the understanding of the peculiar accumulation of these health-promoting metabolites in eggplant, we report on metabolite abundance, regulation of CGA and anthocyanin biosynthesis, and characterization of candidate CGA biosynthetic genes in S. melongena.Higher contents of CGA, Delphinidin 3-rutinoside and rutin were found in eggplant fruits compared to other tissues, associated to an elevated transcript abundance of structural genes such as PAL, HQT, DFR and ANS, suggesting that active in situ biosynthesis contributes to anthocyanin and CGA accumulation in fruit tissues. Putative orthologs of the two CGA biosynthetic genes PAL and HQT, as well as a variant of a MYB1 transcription factor showing identity with group 6 MYBs, were isolated from an Occidental S. melongena traditional variety and demonstrated to differ from published sequences from Asiatic varieties.In silico analysis of the isolated SmPAL1, SmHQT1, SmANS, and SmMyb1 promoters revealed the presence of several Myb regulatory elements for the biosynthetic genes and unique elements for the TF, suggesting its involvement in other physiological roles beside phenylpropanoid biosynthesis regulation.Transient overexpression in Nicotiana benthamiana leaves of SmMyb1 and of a C-terminal SmMyb1 truncated form (SmMyb1Δ9 resulted in anthocyanin accumulation only of SmMyb1 agro-infiltrated leaves. A yeast two-hybrid assay confirmed the interaction of both SmMyb1 and SmMyb1Δ9 with an anthocyanin-related potato bHLH1 TF. Interestingly, a doubled amount of CGA was detected in both SmMyb1 and SmMyb1Δ9 agro-infiltrated leaves, thus suggesting that the N-terminal region of SmMyb1 is sufficient to activate its synthesis. These data suggest that a deletion of

  12. Heterologous Expression of the Oxytetracycline Biosynthetic Pathway in Myxococcus xanthus▿

    Science.gov (United States)

    Stevens, D. Cole; Henry, Michael R.; Murphy, Kimberly A.; Boddy, Christopher N.

    2010-01-01

    New natural products for drug discovery may be accessed by heterologous expression of bacterial biosynthetic pathways in metagenomic DNA libraries. However, a “universal” host is needed for this experiment. Herein, we show that Myxococcus xanthus is a potential “universal” host for heterologous expression of polyketide biosynthetic gene clusters. PMID:20208031

  13. Differential hexosamine biosynthetic pathway gene expression with type 2 diabetes

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    Megan Coomer

    2014-01-01

    Full Text Available The hexosamine biosynthetic pathway (HBP culminates in the attachment of O-linked β-N-acetylglucosamine (O-GlcNAc onto serine/threonine residues of target proteins. The HBP is regulated by several modulators, i.e. O-linked β-N-acetylglucosaminyl transferase (OGT and β-N-acetylglucosaminidase (OGA catalyze the addition and removal of O-GlcNAc moieties, respectively; while flux is controlled by the rate-limiting enzyme glutamine:fructose-6-phosphate amidotransferase (GFPT, transcribed by two genes, GFPT1 and GFPT2. Since increased HBP flux is glucose-responsive and linked to insulin resistance/type 2 diabetes onset, we hypothesized that diabetic individuals exhibit differential expression of HBP regulatory genes. Volunteers (n = 60; n = 20 Mixed Ancestry, n = 40 Caucasian were recruited from Stellenbosch and Paarl (Western Cape, South Africa and classified as control, pre- or diabetic according to fasting plasma glucose and HbA1c levels, respectively. RNA was purified from leukocytes isolated from collected blood samples and OGT, OGA, GFPT1 and GFPT2 expressions determined by quantitative real-time PCR. The data reveal lower OGA expression in diabetic individuals (P < 0.01, while pre- and diabetic subjects displayed attenuated OGT expression vs. controls (P < 0.01 and P < 0.001, respectively. Moreover, GFPT2 expression decreased in pre- and diabetic Caucasians vs. controls (P < 0.05 and P < 0.01, respectively. We also found ethnic differences, i.e. Mixed Ancestry individuals exhibited a 2.4-fold increase in GFPT2 expression vs. Caucasians, despite diagnosis (P < 0.01. Gene expression of HBP regulators differs between diabetic and non-diabetic individuals, together with distinct ethnic-specific gene profiles. Thus differential HBP gene regulation may offer diagnostic utility and provide candidate susceptibility genes for different ethnic groupings.

  14. Development of a gene cloning system in a fast-growing and moderately thermophilic Streptomyces species and heterologous expression of Streptomyces antibiotic biosynthetic gene clusters

    Science.gov (United States)

    2011-01-01

    Background Streptomyces species are a major source of antibiotics. They usually grow slowly at their optimal temperature and fermentation of industrial strains in a large scale often takes a long time, consuming more energy and materials than some other bacterial industrial strains (e.g., E. coli and Bacillus). Most thermophilic Streptomyces species grow fast, but no gene cloning systems have been developed in such strains. Results We report here the isolation of 41 fast-growing (about twice the rate of S. coelicolor), moderately thermophilic (growing at both 30°C and 50°C) Streptomyces strains, detection of one linear and three circular plasmids in them, and sequencing of a 6996-bp plasmid, pTSC1, from one of them. pTSC1-derived pCWH1 could replicate in both thermophilic and mesophilic Streptomyces strains. On the other hand, several Streptomyces replicons function in thermophilic Streptomyces species. By examining ten well-sporulating strains, we found two promising cloning hosts, 2C and 4F. A gene cloning system was established by using the two strains. The actinorhodin and anthramycin biosynthetic gene clusters from mesophilic S. coelicolor A3(2) and thermophilic S. refuineus were heterologously expressed in one of the hosts. Conclusions We have developed a gene cloning and expression system in a fast-growing and moderately thermophilic Streptomyces species. Although just a few plasmids and one antibiotic biosynthetic gene cluster from mesophilic Streptomyces were successfully expressed in thermophilic Streptomyces species, we expect that by utilizing thermophilic Streptomyces-specific promoters, more genes and especially antibiotic genes clusters of mesophilic Streptomyces should be heterologously expressed. PMID:22032628

  15. An indigoidine biosynthetic gene cluster from Streptomyces chromofuscus ATCC 49982 contains an unusual IndB homologue.

    Science.gov (United States)

    Yu, Dayu; Xu, Fuchao; Valiente, Jonathan; Wang, Siyuan; Zhan, Jixun

    2013-01-01

    A putative indigoidine biosynthetic gene cluster was located in the genome of Streptomyces chromofuscus ATCC 49982. The silent 9.4-kb gene cluster consists of five open reading frames, named orf1, Sc-indC, Sc-indA, Sc-indB, and orf2, respectively. Sc-IndC was functionally characterized as an indigoidine synthase through heterologous expression of the enzyme in both Streptomyces coelicolor CH999 and Escherichia coli BAP1. The yield of indigoidine in E. coli BAP1 reached 2.78 g/l under the optimized conditions. The predicted protein product of Sc-indB is unusual and much larger than any other reported IndB-like protein. The N-terminal portion of this enzyme resembles IdgB and the C-terminal portion is a hypothetical protein. Sc-IndA and/or Sc-IndB were co-expressed with Sc-IndC in E. coli BAP1, which demonstrated the involvement of Sc-IndB, but not Sc-IndA, in the biosynthetic pathway of indigoidine. The yield of indigoidine was dramatically increased by 41.4 % (3.93 g/l) when Sc-IndB was co-expressed with Sc-IndC in E. coli BAP1. Indigoidine is more stable at low temperatures.

  16. Functional characterization of KanP, a methyltransferase from the kanamycin biosynthetic gene cluster of Streptomyces kanamyceticus.

    Science.gov (United States)

    Nepal, Keshav Kumar; Yoo, Jin Cheol; Sohng, Jae Kyung

    2010-09-20

    KanP, a putative methyltransferase, is located in the kanamycin biosynthetic gene cluster of Streptomyces kanamyceticus ATCC12853. Amino acid sequence analysis of KanP revealed the presence of S-adenosyl-L-methionine binding motifs, which are present in other O-methyltransferases. The kanP gene was expressed in Escherichia coli BL21 (DE3) to generate the E. coli KANP recombinant strain. The conversion of external quercetin to methylated quercetin in the culture extract of E. coli KANP proved the function of kanP as S-adenosyl-L-methionine-dependent methyltransferase. This is the first report concerning the identification of an O-methyltransferase gene from the kanamycin gene cluster. The resistant activity assay and RT-PCR analysis demonstrated the leeway for obtaining methylated kanamycin derivatives from the wild-type strain of kanamycin producer. 2009 Elsevier GmbH. All rights reserved.

  17. In planta functions of cytochrome P450 monooxygenase genes in the phytocassane biosynthetic gene cluster on rice chromosome 2.

    Science.gov (United States)

    Ye, Zhongfeng; Yamazaki, Kohei; Minoda, Hiromi; Miyamoto, Koji; Miyazaki, Sho; Kawaide, Hiroshi; Yajima, Arata; Nojiri, Hideaki; Yamane, Hisakazu; Okada, Kazunori

    2018-06-01

    In response to environmental stressors such as blast fungal infections, rice produces phytoalexins, an antimicrobial diterpenoid compound. Together with momilactones, phytocassanes are among the major diterpenoid phytoalexins. The biosynthetic genes of diterpenoid phytoalexin are organized on the chromosome in functional gene clusters, comprising diterpene cyclase, dehydrogenase, and cytochrome P450 monooxygenase genes. Their functions have been studied extensively using in vitro enzyme assay systems. Specifically, P450 genes (CYP71Z6, Z7; CYP76M5, M6, M7, M8) on rice chromosome 2 have multifunctional activities associated with ent-copalyl diphosphate-related diterpene hydrocarbons, but the in planta contribution of these genes to diterpenoid phytoalexin production remains unknown. Here, we characterized cyp71z7 T-DNA mutant and CYP76M7/M8 RNAi lines to find that potential phytoalexin intermediates accumulated in these P450-suppressed rice plants. The results suggested that in planta, CYP71Z7 is responsible for C2-hydroxylation of phytocassanes and that CYP76M7/M8 is involved in C11α-hydroxylation of 3-hydroxy-cassadiene. Based on these results, we proposed potential routes of phytocassane biosynthesis in planta.

  18. Expression of ethylene biosynthetic and receptor genes in rose floral tissues during ethylene-enhanced flower opening

    OpenAIRE

    Xue, Jingqi; Li, Yunhui; Tan, Hui; Yang, Feng; Ma, Nan; Gao, Junping

    2008-01-01

    Ethylene production, as well as the expression of ethylene biosynthetic (Rh-ACS1?4 and Rh-ACO1) and receptor (Rh-ETR1?5) genes, was determined in five different floral tissues (sepals, petals, stamens, gynoecia, and receptacles) of cut rose (Rosa hybrida cv. Samantha upon treatment with ethylene or the ethylene inhibitor 1-methylcyclopropene (1-MCP). Ethylene-enhanced ethylene production occurred only in gynoecia, petals, and receptacles, with gynoecia showing the greatest enhancement in the ...

  19. Natural Product Biosynthetic Diversity and Comparative Genomics of the Cyanobacteria.

    Science.gov (United States)

    Dittmann, Elke; Gugger, Muriel; Sivonen, Kaarina; Fewer, David P

    2015-10-01

    Cyanobacteria are an ancient lineage of slow-growing photosynthetic bacteria and a prolific source of natural products with intricate chemical structures and potent biological activities. The bulk of these natural products are known from just a handful of genera. Recent efforts have elucidated the mechanisms underpinning the biosynthesis of a diverse array of natural products from cyanobacteria. Many of the biosynthetic mechanisms are unique to cyanobacteria or rarely described from other organisms. Advances in genome sequence technology have precipitated a deluge of genome sequences for cyanobacteria. This makes it possible to link known natural products to biosynthetic gene clusters but also accelerates the discovery of new natural products through genome mining. These studies demonstrate that cyanobacteria encode a huge variety of cryptic gene clusters for the production of natural products, and the known chemical diversity is likely to be just a fraction of the true biosynthetic capabilities of this fascinating and ancient group of organisms. Copyright © 2015. Published by Elsevier Ltd.

  20. Genetic determination of the meso-diaminopimelate biosynthetic pathway of mycobacteria.

    Science.gov (United States)

    Cirillo, J D; Weisbrod, T R; Banerjee, A; Bloom, B R; Jacobs, W R

    1994-07-01

    The increasing incidence of multiple-drug-resistant mycobacterial infections indicates that the development of new methods for treatment of mycobacterial diseases should be a high priority. meso-Diaminopimelic acid (DAP), a key component of a highly immunogenic subunit of the mycobacterial peptidoglycan layer, has been implicated as a potential virulence factor. The mycobacterial DAP biosynthetic pathway could serve as a target for design of new antimycobacterial agents as well as the construction of in vivo selection systems. We have isolated the asd, dapA, dapB, dapD, and dapE genes involved in the DAP biosynthetic pathway of Mycobacterium bovis BCG. These genes were isolated by complementation of Escherichia coli mutations with an expression library of BCG DNA. Our analysis of these genes suggests that BCG may use more than one pathway for biosynthesis of DAP. The nucleotide sequence of the BCG dapB gene was determined. The activity of the product of this gene in Escherichia coli provided evidence that the gene may encode a novel bifunctional dihydrodipicolinate reductase and DAP dehydrogenase.

  1. Linking metabolic QTLs with network and cis-eQTLs controlling biosynthetic pathways.

    Directory of Open Access Journals (Sweden)

    Adam M Wentzell

    2007-09-01

    Full Text Available Phenotypic variation between individuals of a species is often under quantitative genetic control. Genomic analysis of gene expression polymorphisms between individuals is rapidly gaining popularity as a way to query the underlying mechanistic causes of variation between individuals. However, there is little direct evidence of a linkage between global gene expression polymorphisms and phenotypic consequences. In this report, we have mapped quantitative trait loci (QTLs-controlling glucosinolate content in a population of 403 Arabidopsis Bay x Sha recombinant inbred lines, 211 of which were previously used to identify expression QTLs controlling the transcript levels of biosynthetic genes. In a comparative study, we have directly tested two plant biosynthetic pathways for association between polymorphisms controlling biosynthetic gene transcripts and the resulting metabolites within the Arabidopsis Bay x Sha recombinant inbred line population. In this analysis, all loci controlling expression variation also affected the accumulation of the resulting metabolites. In addition, epistasis was detected more frequently for metabolic traits compared to transcript traits, even when both traits showed similar distributions. An analysis of candidate genes for QTL-controlling networks of transcripts and metabolites suggested that the controlling factors are a mix of enzymes and regulatory factors. This analysis showed that regulatory connections can feedback from metabolism to transcripts. Surprisingly, the most likely major regulator of both transcript level for nearly the entire pathway and aliphatic glucosinolate accumulation is variation in the last enzyme in the biosynthetic pathway, AOP2. This suggests that natural variation in transcripts may significantly impact phenotypic variation, but that natural variation in metabolites or their enzymatic loci can feed back to affect the transcripts.

  2. Enhancement of cordyceps polysaccharide production via biosynthetic pathway analysis in Hirsutella sinensis.

    Science.gov (United States)

    Lin, Shan; Liu, Zhi-Qiang; Baker, Peter James; Yi, Ming; Wu, Hui; Xu, Feng; Teng, Yi; Zheng, Yu-Guo

    2016-11-01

    The addition of various sulfates for enhanced cordyceps polysaccharide (CP) production in submerged cultivation of H. sinensis was investigated, and manganese sulfate was found the most effective. 2mM of manganese sulfate on 0day (d) was investigated as the optimal adding condition, and the CP production reached optimum with 5.33%, increasing by 93.3% compared with the control. Furthermore, the consumption of three main precursors of CP was studied over cultivation under two conditions. Intracellular mannose content decreased by 43.1% throughout 6days cultivation, which corresponded to CP accumulation rate sharply increased from 0 d to 6 d, and mannose was considered as the most preferred precursor for generating CP. Subsequently, mannose biosynthetic pathway was constructed and verified for the first time in H. sinensis, which constituted the important part of CP biosynthesis, and transcriptional levels of the biosynthetic genes were studied. Transcriptional level of gene cpsA was significantly up-regulated 5.35-fold and it was a key gene involved both in mannose and CP biosynthesis. This study demonstrated that manganese sulfate addition is an efficient and simple way to improve CP production. Transcriptional analysis based on biosynthetic pathway was helpful to find key genes and better understand CP biosynthesis. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Cloning, reassembling and integration of the entire nikkomycin biosynthetic gene cluster into Streptomyces ansochromogenes lead to an improved nikkomycin production

    Directory of Open Access Journals (Sweden)

    Yang Haihua

    2010-01-01

    Full Text Available Abstract Background Nikkomycins are a group of peptidyl nucleoside antibiotics produced by Streptomyces ansochromogenes. They are competitive inhibitors of chitin synthase and show potent fungicidal, insecticidal, and acaricidal activities. Nikkomycin X and Z are the main components produced by S. ansochromogenes. Generation of a high-producing strain is crucial to scale up nikkomycins production for further clinical trials. Results To increase the yields of nikkomycins, an additional copy of nikkomycin biosynthetic gene cluster (35 kb was introduced into nikkomycin producing strain, S. ansochromogenes 7100. The gene cluster was first reassembled into an integrative plasmid by Red/ET technology combining with classic cloning methods and then the resulting plasmid(pNIKwas introduced into S. ansochromogenes by conjugal transfer. Introduction of pNIK led to enhanced production of nikkomycins (880 mg L-1, 4 -fold nikkomycin X and 210 mg L-1, 1.8-fold nikkomycin Z in the resulting exconjugants comparing with the parent strain (220 mg L-1 nikkomycin X and 120 mg L-1 nikkomycin Z. The exconjugants are genetically stable in the absence of antibiotic resistance selection pressure. Conclusion A high nikkomycins producing strain (1100 mg L-1 nikkomycins was obtained by introduction of an extra nikkomycin biosynthetic gene cluster into the genome of S. ansochromogenes. The strategies presented here could be applicable to other bacteria to improve the yields of secondary metabolites.

  4. Detection of biosynthetic gene and phytohormone production by endophytic actinobacteria associated with Solanum lycopersicum and their plant-growth-promoting effect.

    Science.gov (United States)

    Passari, Ajit Kumar; Chandra, Preeti; Zothanpuia; Mishra, Vineet Kumar; Leo, Vincent Vineeth; Gupta, Vijai Kumar; Kumar, Brijesh; Singh, Bhim Pratap

    2016-10-01

    In the present study, fifteen endophytic actinobacterial isolates recovered from Solanum lycopersicum were studied for their antagonistic potential and plant-growth-promoting (PGP) traits. Among them, eight isolates showed significant antagonistic and PGP traits, identified by amplification of the 16S rRNA gene. Isolate number DBT204, identified as Streptomyces sp., showed multiple PGP traits tested in planta and improved a range of growth parameters in seedlings of chili (Capsicum annuum L.) and tomato (S. lycopersicum L.). Further, genes of indole acetic acid (iaaM) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase (acdS) were successively amplified from five strains. Six antibiotics (trimethoprim, fluconazole, chloramphenicol, nalidixic acid, rifampicin and streptomycin) and two phytohormones [indole acetic acid (IAA) and kinetin (KI)] were detected and quantified in Streptomyces sp. strain DBT204 using UPLC-ESI-MS/MS. The study indicates the potential of these PGP strains for production of phytohormones and shows the presence of biosynthetic genes responsible for production of secondary metabolites. It is the first report showing production of phytohormones (IAA and KI) by endophytic actinobacteria having PGP and biosynthetic potential. We propose Streptomyces sp. strain DBT204 for inoculums production and development of biofertilizers for enhancing growth of chili and tomato seedlings. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  5. Antibiotic discovery throughout the Small World Initiative: A molecular strategy to identify biosynthetic gene clusters involved in antagonistic activity.

    Science.gov (United States)

    Davis, Elizabeth; Sloan, Tyler; Aurelius, Krista; Barbour, Angela; Bodey, Elijah; Clark, Brigette; Dennis, Celeste; Drown, Rachel; Fleming, Megan; Humbert, Allison; Glasgo, Elizabeth; Kerns, Trent; Lingro, Kelly; McMillin, MacKenzie; Meyer, Aaron; Pope, Breanna; Stalevicz, April; Steffen, Brittney; Steindl, Austin; Williams, Carolyn; Wimberley, Carmen; Zenas, Robert; Butela, Kristen; Wildschutte, Hans

    2017-06-01

    The emergence of bacterial pathogens resistant to all known antibiotics is a global health crisis. Adding to this problem is that major pharmaceutical companies have shifted away from antibiotic discovery due to low profitability. As a result, the pipeline of new antibiotics is essentially dry and many bacteria now resist the effects of most commonly used drugs. To address this global health concern, citizen science through the Small World Initiative (SWI) was formed in 2012. As part of SWI, students isolate bacteria from their local environments, characterize the strains, and assay for antibiotic production. During the 2015 fall semester at Bowling Green State University, students isolated 77 soil-derived bacteria and genetically characterized strains using the 16S rRNA gene, identified strains exhibiting antagonistic activity, and performed an expanded SWI workflow using transposon mutagenesis to identify a biosynthetic gene cluster involved in toxigenic compound production. We identified one mutant with loss of antagonistic activity and through subsequent whole-genome sequencing and linker-mediated PCR identified a 24.9 kb biosynthetic gene locus likely involved in inhibitory activity in that mutant. Further assessment against human pathogens demonstrated the inhibition of Bacillus cereus, Listeria monocytogenes, and methicillin-resistant Staphylococcus aureus in the presence of this compound, thus supporting our molecular strategy as an effective research pipeline for SWI antibiotic discovery and genetic characterization. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  6. Identification of an unusual type II thioesterase in the dithiolopyrrolone antibiotics biosynthetic pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Ying; Bai, Silei; Liu, Jingjing; Yang, Liyuan [National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Han, Li; Huang, Xueshi [Institute of Microbial Pharmaceuticals, College of Life and Health Sciences, Northeastern University, Shenyang 110819 (China); He, Jing, E-mail: hejingjj@mail.hzau.edu.cn [National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China)

    2016-04-22

    Dithiolopyrrolone group antibiotics characterized by an electronically unique dithiolopyrrolone heterobicyclic core are known for their antibacterial, antifungal, insecticidal and antitumor activities. Recently the biosynthetic gene clusters for two dithiolopyrrolone compounds, holomycin and thiomarinol, have been identified respectively in different bacterial species. Here, we report a novel dithiolopyrrolone biosynthetic gene cluster (aut) isolated from Streptomyces thioluteus DSM 40027 which produces two pyrrothine derivatives, aureothricin and thiolutin. By comparison with other characterized dithiolopyrrolone clusters, eight genes in the aut cluster were verified to be responsible for the assembly of dithiolopyrrolone core. The aut cluster was further confirmed by heterologous expression and in-frame gene deletion experiments. Intriguingly, we found that the heterogenetic thioesterase HlmK derived from the holomycin (hlm) gene cluster in Streptomyces clavuligerus significantly improved heterologous biosynthesis of dithiolopyrrolones in Streptomyces albus through coexpression with the aut cluster. In the previous studies, HlmK was considered invalid because it has a Ser to Gly point mutation within the canonical Ser-His-Asp catalytic triad of thioesterases. However, gene inactivation and complementation experiments in our study unequivocally demonstrated that HlmK is an active distinctive type II thioesterase that plays a beneficial role in dithiolopyrrolone biosynthesis. - Highlights: • Cloning of the aureothricin biosynthetic gene cluster from Streptomyces thioluteus DSM 40027. • Identification of the aureothricin gene cluster by heterologous expression and in-frame gene deletion. • The heterogenetic thioesterase HlmK significantly improved dithiolopyrrolones production of the aureothricin gene cluster. • Identification of HlmK as an unusual type II thioesterase.

  7. Identification of an unusual type II thioesterase in the dithiolopyrrolone antibiotics biosynthetic pathway

    International Nuclear Information System (INIS)

    Zhai, Ying; Bai, Silei; Liu, Jingjing; Yang, Liyuan; Han, Li; Huang, Xueshi; He, Jing

    2016-01-01

    Dithiolopyrrolone group antibiotics characterized by an electronically unique dithiolopyrrolone heterobicyclic core are known for their antibacterial, antifungal, insecticidal and antitumor activities. Recently the biosynthetic gene clusters for two dithiolopyrrolone compounds, holomycin and thiomarinol, have been identified respectively in different bacterial species. Here, we report a novel dithiolopyrrolone biosynthetic gene cluster (aut) isolated from Streptomyces thioluteus DSM 40027 which produces two pyrrothine derivatives, aureothricin and thiolutin. By comparison with other characterized dithiolopyrrolone clusters, eight genes in the aut cluster were verified to be responsible for the assembly of dithiolopyrrolone core. The aut cluster was further confirmed by heterologous expression and in-frame gene deletion experiments. Intriguingly, we found that the heterogenetic thioesterase HlmK derived from the holomycin (hlm) gene cluster in Streptomyces clavuligerus significantly improved heterologous biosynthesis of dithiolopyrrolones in Streptomyces albus through coexpression with the aut cluster. In the previous studies, HlmK was considered invalid because it has a Ser to Gly point mutation within the canonical Ser-His-Asp catalytic triad of thioesterases. However, gene inactivation and complementation experiments in our study unequivocally demonstrated that HlmK is an active distinctive type II thioesterase that plays a beneficial role in dithiolopyrrolone biosynthesis. - Highlights: • Cloning of the aureothricin biosynthetic gene cluster from Streptomyces thioluteus DSM 40027. • Identification of the aureothricin gene cluster by heterologous expression and in-frame gene deletion. • The heterogenetic thioesterase HlmK significantly improved dithiolopyrrolones production of the aureothricin gene cluster. • Identification of HlmK as an unusual type II thioesterase.

  8. VIGS approach reveals the modulation of anthocyanin biosynthetic genes by CaMYB in Chili pepper leaves

    Directory of Open Access Journals (Sweden)

    zhen ezhang

    2015-07-01

    Full Text Available The purple coloration of pepper leaves arises from the accumulation of anthocyanin. Three regulatory and 12 structural genes have been characterized for their involvement in the anthocyanin biosynthesis. Examination of the abundance of these genes in leaves showed that the majority of them differed between anthocyanin pigmented line Z1 and non-pigmented line A3. Silencing of the R2R3-MYB transcription factor CaMYB in pepper leaves of Z1 resulted in the loss of anthocyanin accumulation. Moreover, the expression of multiple genes was altered in the silenced leaves. The expression of MYC was significantly lower in CaMYB-silenced leaves, whereas WD40 showed the opposite pattern. Most structural genes including CHS, CHI, F3H, F3’5’H, DFR, ANS, UFGT, ANP and GST were repressed in CaMYB-silenced foliage with the exception of PAL, C4H and 4CL. These results indicated that MYB plays an important role in the regulation of anthocyanin biosynthetic related genes. Besides CaMYB silenced leaves rendered more sporulation of Phytophthora capsici Leonian indicating that CaMYB might be involved in the defense response to pathogens.

  9. Evolutionary systems biology of amino acid biosynthetic cost in yeast.

    Directory of Open Access Journals (Sweden)

    Michael D Barton

    2010-08-01

    Full Text Available Every protein has a biosynthetic cost to the cell based on the synthesis of its constituent amino acids. In order to optimise growth and reproduction, natural selection is expected, where possible, to favour the use of proteins whose constituents are cheaper to produce, as reduced biosynthetic cost may confer a fitness advantage to the organism. Quantifying the cost of amino acid biosynthesis presents challenges, since energetic requirements may change across different cellular and environmental conditions. We developed a systems biology approach to estimate the cost of amino acid synthesis based on genome-scale metabolic models and investigated the effects of the cost of amino acid synthesis on Saccharomyces cerevisiae gene expression and protein evolution. First, we used our two new and six previously reported measures of amino acid cost in conjunction with codon usage bias, tRNA gene number and atomic composition to identify which of these factors best predict transcript and protein levels. Second, we compared amino acid cost with rates of amino acid substitution across four species in the genus Saccharomyces. Regardless of which cost measure is used, amino acid biosynthetic cost is weakly associated with transcript and protein levels. In contrast, we find that biosynthetic cost and amino acid substitution rates show a negative correlation, but for only a subset of cost measures. In the economy of the yeast cell, we find that the cost of amino acid synthesis plays a limited role in shaping transcript and protein expression levels compared to that of translational optimisation. Biosynthetic cost does, however, appear to affect rates of amino acid evolution in Saccharomyces, suggesting that expensive amino acids may only be used when they have specific structural or functional roles in protein sequences. However, as there appears to be no single currency to compute the cost of amino acid synthesis across all cellular and environmental

  10. Biosynthetic Pathway and Metabolic Engineering of Plant Dihydrochalcones.

    Science.gov (United States)

    Ibdah, Mwafaq; Martens, Stefan; Gang, David R

    2018-03-14

    Dihydrochalcones are plant natural products containing the phenylpropanoid backbone and derived from the plant-specific phenylpropanoid pathway. Dihydrochalcone compounds are important in plant growth and response to stresses and, thus, can have large impacts on agricultural activity. In recent years, these compounds have also received increased attention from the biomedical community for their potential as anticancer treatments and other benefits for human health. However, they are typically produced at relatively low levels in plants. Therefore, an attractive alternative is to express the plant biosynthetic pathway genes in microbial hosts and to engineer the metabolic pathway/host to improve the production of these metabolites. In the present review, we discuss in detail the functions of genes and enzymes involved in the biosynthetic pathway of the dihydrochalcones and the recent strategies and achievements used in the reconstruction of multi-enzyme pathways in microorganisms in efforts to be able to attain higher amounts of desired dihydrochalcones.

  11. Variation in the fumonisin biosynthetic gene cluster in fumonisin-producing and nonproducing black aspergilli.

    Science.gov (United States)

    Susca, Antonia; Proctor, Robert H; Butchko, Robert A E; Haidukowski, Miriam; Stea, Gaetano; Logrieco, Antonio; Moretti, Antonio

    2014-12-01

    The ability to produce fumonisin mycotoxins varies among members of the black aspergilli. Previously, analyses of selected genes in the fumonisin biosynthetic gene (fum) cluster in black aspergilli from California grapes indicated that fumonisin-nonproducing isolates of Aspergillus welwitschiae lack six fum genes, but nonproducing isolates of Aspergillus niger do not. In the current study, analyses of black aspergilli from grapes from the Mediterranean Basin indicate that the genomic context of the fum cluster is the same in isolates of A. niger and A. welwitschiae regardless of fumonisin-production ability and that full-length clusters occur in producing isolates of both species and nonproducing isolates of A. niger. In contrast, the cluster has undergone an eight-gene deletion in fumonisin-nonproducing isolates of A. welwitschiae. Phylogenetic analyses suggest each species consists of a mixed population of fumonisin-producing and nonproducing individuals, and that existence of both production phenotypes may provide a selective advantage to these species. Differences in gene content of fum cluster homologues and phylogenetic relationships of fum genes suggest that the mutation(s) responsible for the nonproduction phenotype differs, and therefore arose independently, in the two species. Partial fum cluster homologues were also identified in genome sequences of four other black Aspergillus species. Gene content of these partial clusters and phylogenetic relationships of fum sequences indicate that non-random partial deletion of the cluster has occurred multiple times among the species. This in turn suggests that an intact cluster and fumonisin production were once more widespread among black aspergilli. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Description of a Riboflavin Biosynthetic Gene Variant Prevalent in the Phylum Proteobacteria

    Science.gov (United States)

    Brutinel, Evan D.; Dean, Antony M.

    2013-01-01

    Riboflavin (vitamin B2) is the precursor of flavin mononucleotide and flavin adenine dinucleotide, which are cofactors essential for a host of intracellular redox reactions. Microorganisms synthesize flavins de novo to fulfill nutritional requirements, but it is becoming increasingly clear that flavins play a wider role in cellular physiology than was previously appreciated. Flavins mediate diverse processes beyond the cytoplasmic membrane, including iron acquisition, extracellular respiration, and interspecies interactions. While investigating the regulation of flavin electron shuttle biosynthesis in the Gram-negative gammaproteobacterium Shewanella oneidensis, we discovered that a riboflavin biosynthetic gene (ribBA) annotated as encoding a bifunctional 3,4-dihydroxy-2-butanone 4-phosphate (DHBP) synthase/GTP cyclohydrolase II does not possess both functions. The novel gene, renamed ribBX here, encodes an amino-terminal DHBP synthase domain. The carboxy-terminal end of RibBX not only lacks GTP cyclohydrolase II activity but also has evolved a different function altogether in S. oneidensis, regulating the activity of the DHBP synthase domain. Phylogenetic analysis revealed that the misannotation of ribBX as ribBA is rampant throughout the phylum Proteobacteria (40% of 2,173 annotated ribBA genes) and that ribBX emerged early in the evolution of this group of microorganisms. We examined the functionality of representative ribBX genes from Beta-, Gamma-, and Epsilonproteobacteria and found that, consistent with sequence-based predictions, the encoded GTP cyclohydrolase II domains lack catalytic activity. The persistence of ribBX in the genomes of so many phylogenetically divergent bacterial species lends weight to the argument that ribBX has evolved a function which lends a selective advantage to the host. PMID:24097946

  13. Glutamic acid promotes monacolin K production and monacolin K biosynthetic gene cluster expression in Monascus.

    Science.gov (United States)

    Zhang, Chan; Liang, Jian; Yang, Le; Chai, Shiyuan; Zhang, Chenxi; Sun, Baoguo; Wang, Chengtao

    2017-12-01

    This study investigated the effects of glutamic acid on production of monacolin K and expression of the monacolin K biosynthetic gene cluster. When Monascus M1 was grown in glutamic medium instead of in the original medium, monacolin K production increased from 48.4 to 215.4 mg l -1 , monacolin K production increased by 3.5 times. Glutamic acid enhanced monacolin K production by upregulating the expression of mokB-mokI; on day 8, the expression level of mokA tended to decrease by Reverse Transcription-polymerase Chain Reaction. Our findings demonstrated that mokA was not a key gene responsible for the quantity of monacolin K production in the presence of glutamic acid. Observation of Monascus mycelium morphology using Scanning Electron Microscope showed glutamic acid significantly increased the content of Monascus mycelium, altered the permeability of Monascus mycelium, enhanced secretion of monacolin K from the cell, and reduced the monacolin K content in Monascus mycelium, thereby enhancing monacolin K production.

  14. Output ordering and prioritisation system (OOPS): ranking biosynthetic gene clusters to enhance bioactive metabolite discovery.

    Science.gov (United States)

    Peña, Alejandro; Del Carratore, Francesco; Cummings, Matthew; Takano, Eriko; Breitling, Rainer

    2017-12-18

    The rapid increase of publicly available microbial genome sequences has highlighted the presence of hundreds of thousands of biosynthetic gene clusters (BGCs) encoding valuable secondary metabolites. The experimental characterization of new BGCs is extremely laborious and struggles to keep pace with the in silico identification of potential BGCs. Therefore, the prioritisation of promising candidates among computationally predicted BGCs represents a pressing need. Here, we propose an output ordering and prioritisation system (OOPS) which helps sorting identified BGCs by a wide variety of custom-weighted biological and biochemical criteria in a flexible and user-friendly interface. OOPS facilitates a judicious prioritisation of BGCs using G+C content, coding sequence length, gene number, cluster self-similarity and codon bias parameters, as well as enabling the user to rank BGCs based upon BGC type, novelty, and taxonomic distribution. Effective prioritisation of BGCs will help to reduce experimental attrition rates and improve the breadth of bioactive metabolites characterized.

  15. Modulation of flavonoid biosynthetic pathway genes and anthocyanins due to virus infection in grapevine (Vitis vinifera L. leaves

    Directory of Open Access Journals (Sweden)

    Gutha Linga R

    2010-08-01

    Full Text Available Abstract Background Symptoms of grapevine leafroll disease (GLRD in red-fruited wine grape (Vitis vinifera L. cultivars consist of green veins and red and reddish-purple discoloration of inter-veinal areas of leaves. The reddish-purple color of symptomatic leaves may be due to the accumulation of anthocyanins and could reflect an up-regulation of genes involved in their biosynthesis. Results We examined six putative constitutively expressed genes, Ubiquitin, Actin, GAPDH, EF1-a, SAND and NAD5, for their potential as references for normalization of gene expression in reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR. Using the geNorm program, a combination of two genes (Actin and NAD5 was identified as the stable set of reference genes for normalization of gene expression data obtained from grapevine leaves. By using gene-specific RT-qPCR in combination with a reliable normalization factor, we compared relative expression of the flavonoid biosynthetic pathway genes between leaves infected with Grapevine leafroll-associated virus 3 (GLRaV-3 and exhibiting GLRD symptoms and virus-free green leaves obtained from a red-fruited wine grape cultivar (cv. Merlot. The expression levels of these different genes ranged from two- to fifty-fold increase in virus-infected leaves. Among them, CHS3, F3'5'H, F3H1, LDOX, LAR1 and MybA1 showed greater than 10-fold increase suggesting that they were expressed at significantly higher levels in virus-infected symptomatic leaves. HPLC profiling of anthocyanins extracted from leaves indicated the presence of cyanidin-3-glucoside and malvidin-3-glucoside only in virus-infected symptomatic leaves. The results also showed 24% higher levels of flavonols in virus-infected symptomatic leaves than in virus-free green leaves, with quercetin followed by myricetin being the predominant compounds. Proanthocyanidins, estimated as total tannins by protein precipitation method, were 36% higher in virus

  16. Identification and characterization of lbpA, an indigoidine biosynthetic gene in the γ-butyrolactone signaling system of Streptomyces lavendulae FRI-5.

    Science.gov (United States)

    Pait, Ivy Grace Umadhay; Kitani, Shigeru; Kurniawan, Yohanes Novi; Asa, Maeda; Iwai, Takashi; Ikeda, Haruo; Nihira, Takuya

    2017-10-01

    Streptomyces lavendulae FRI-5 produces the blue pigment indigoidine and other secondary metabolites (d-cycloserine and nucleoside antibiotics). The production of these useful compounds is controlled by a signaling cascade mediated by the γ-butyrolactone autoregulator IM-2. Previously we revealed that the far regulatory island includes the IM-2 receptor, the IM-2 biosynthetic enzyme, and several transcriptional regulators, and that it contributes to the regulation of indigoidine production in response to the signaling molecule. Here, we found that the vicinity of the far regulatory island includes the putative gene cluster for the biosynthesis of indigoidine and unidentified compounds, and demonstrated that the expression of the gene cluster is under the control of the IM-2 regulatory system. Heterologous expression of lbpA, encoding a plausible nonribosomal peptide synthetase, in the versatile model host Streptomyces avermitilis SUKA22 led to indigoidine production, which was enhanced dramatically by feeding of the indigoidine precursor l-glutamine. These results confirmed that LbpA is an indigoidine biosynthetic enzyme in the IM-2 signaling cascade. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. In silico analysis and expression profiling of miRNAs targeting genes of steviol glycosides biosynthetic pathway and their relationship with steviol glycosides content in different tissues of Stevia rebaudiana.

    Science.gov (United States)

    Saifi, Monica; Nasrullah, Nazima; Ahmad, Malik Mobeen; Ali, Athar; Khan, Jawaid A; Abdin, M Z

    2015-09-01

    miRNAs are emerging as potential regulators of the gene expression. Their proven promising role in regulating biosynthetic pathways related gene networks may hold the key to understand the genetic regulation of these pathways which may assist in selection and manipulation to get high performing plant genotypes with better secondary metabolites yields and increased biomass. miRNAs associated with genes of steviol glycosides biosynthetic pathway, however, have not been identified so far. In this study miRNAs targeting genes of steviol glycosides biosynthetic pathway were identified for the first time whose precursors were potentially generated from ESTs and nucleotide sequences of Stevia rebaudiana. Thereafter, stem-loop coupled real time PCR based expressions of these miRNAs in different tissues of Stevia rebaudiana were investigated and their relationship pattern was analysed with the expression levels of their target mRNAs as well as steviol glycoside contents. All the miRNAs investigated showed differential expressions in all the three tissues studied, viz. leaves, flowers and stems. Out of the eleven miRNAs validated, the expression levels of nine miRNAs (miR319a, miR319b, miR319c, miR319d, miR319e, miR319f, miR319h, miRstv_7, miRstv_9) were found to be inversely related, while expression levels of the two, i.e. miR319g and miRstv_11 on the contrary, showed direct relation with the expression levels of their target mRNAs and steviol glycoside contents in the leaves, flowers and stems. This study provides a platform for better understanding of the steviol glycosides biosynthetic pathway and these miRNAs can further be employed to manipulate the biosynthesis of these metabolites to enhance their contents and yield in S. rebaudiana. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  18. Distribution and Biocontrol Potential of phlD(+) Pseudomonads in Corn and Soybean Fields.

    Science.gov (United States)

    McSpadden Gardener, Brian B; Gutierrez, Laura J; Joshi, Raghavendra; Edema, Richard; Lutton, Elizabeth

    2005-06-01

    ABSTRACT The abundance and diversity of phlD(+) Pseudomonas spp. colonizing the rhizospheres of young, field-grown corn and soybean plants were assayed over a 3-year period. Populations of these bacteria were detected on the large majority of plants sampled in the state of Ohio, but colonization was greater on corn. Although significant variation in the incidence of rhizosphere colonization was observed from site to site and year to year on both crops, the magnitude of the variation was greatest for soybean. The D genotype was detected on plants collected from all 15 counties examined, and it represented the most abundant subpopulation on both crops. Additionally, six other genotypes (A, C, F, I, R, and S) were found to predominate in the rhizosphere of some plants. The most frequently observed of these were the A genotype and a newly discovered S genotype, both of which were found on corn and soybean roots obtained from multiple locations. Multiple isolates of the most abundant genotypes were recovered and characterized. The S genotype was found to be phylogenetically and phenotypically similar to the D genotype. In addition, the novel R genotype was found to be most similar to the A genotype. All of the isolates displayed significant capacities to inhibit the growth of an oomycete pathogen in vitro, but such phenotypes were highly dependent on media used. When tested against multiple oomycete pathogens isolated from soybean, the A genotype was significantly more inhibitory than the D genotype when incubated on 1/10x tryptic soy agar and 1/5x corn meal agar. Seed inoculation with different isolates of the A, D, and S genotypes indicated that significant root colonization, generally in excess of log 5 cells per gram of root, could be attained on both crops. Field trials of the A genotype isolate Wayne1R indicated the capacity of inoculant populations to supplement the activities of native populations so as to increase soybean stands and yields. The relevance of

  19. Distribution of secondary metabolite biosynthetic gene clusters in 343 Fusarium genomes

    Science.gov (United States)

    Fusarium consists of over 200 phylogenetically distinct species, many of which cause important crop diseases and/or produce mycotoxins and other secondary metabolites (SMs). Some fusaria also cause opportunistic infections in humans and other animals. To investigate the distribution of biosynthetic ...

  20. A gene expression analysis of cell wall biosynthetic genes in Malus × domestica infected by ‘Candidatus Phytoplasma mali’

    Science.gov (United States)

    Guerriero, Gea; Giorno, Filomena; Ciccotti, Anna Maria; Schmidt, Silvia; Baric, Sanja

    2016-01-01

    Apple proliferation (AP) represents a serious threat to several fruit-growing areas and is responsible for great economic losses. Several studies have highlighted the key role played by the cell wall in response to pathogen attack. The existence of a cell wall integrity signaling pathway which senses perturbations in the cell wall architecture upon abiotic/biotic stresses and activates specific defence responses has been widely demonstrated in plants. More recently a role played by cell wall-related genes has also been reported in plants infected by phytoplasmas. With the aim of shedding light on the cell wall response to AP disease in the economically relevant fruit-tree Malus × domestica Borkh., we investigated the expression of the cellulose (CesA) and callose synthase (CalS) genes in different organs (i.e., leaves, roots and branch phloem) of healthy and infected symptomatic outdoor-grown trees, sampled over the course of two time points (i.e., spring and autumn 2011), as well as in in vitro micropropagated control and infected plantlets. A strong up-regulation in the expression of cell wall biosynthetic genes was recorded in roots from infected trees. Secondary cell wall CesAs showed up-regulation in the phloem tissue from branches of infected plants, while either a down-regulation of some genes or no major changes were observed in the leaves. Micropropagated plantlets also showed an increase in cell wall-related genes and constitute a useful system for a general assessment of gene expression analysis upon phytoplasma infection. Finally, we also report the presence of several ‘knot’-like structures along the roots of infected apple trees and discuss the occurrence of this interesting phenotype in relation to the gene expression results and the modalities of phytoplasma diffusion. PMID:23086810

  1. Secondary metabolism in Fusarium fujikuroi: strategies to unravel the function of biosynthetic pathways.

    Science.gov (United States)

    Janevska, Slavica; Tudzynski, Bettina

    2018-01-01

    The fungus Fusarium fujikuroi causes bakanae disease of rice due to its ability to produce the plant hormones, the gibberellins. The fungus is also known for producing harmful mycotoxins (e.g., fusaric acid and fusarins) and pigments (e.g., bikaverin and fusarubins). However, for a long time, most of these well-known products could not be linked to biosynthetic gene clusters. Recent genome sequencing has revealed altogether 47 putative gene clusters. Most of them were orphan clusters for which the encoded natural product(s) were unknown. In this review, we describe the current status of our research on identification and functional characterizations of novel secondary metabolite gene clusters. We present several examples where linking known metabolites to the respective biosynthetic genes has been achieved and describe recent strategies and methods to access new natural products, e.g., by genetic manipulation of pathway-specific or global transcritption factors. In addition, we demonstrate that deletion and over-expression of histone-modifying genes is a powerful tool to activate silent gene clusters and to discover their products.

  2. Saponin determination, expression analysis and functional characterization of saponin biosynthetic genes in Chenopodium quinoa leaves.

    Science.gov (United States)

    Fiallos-Jurado, Jennifer; Pollier, Jacob; Moses, Tessa; Arendt, Philipp; Barriga-Medina, Noelia; Morillo, Eduardo; Arahana, Venancio; de Lourdes Torres, Maria; Goossens, Alain; Leon-Reyes, Antonio

    2016-09-01

    Quinoa (Chenopodium quinoa Willd.) is a highly nutritious pseudocereal with an outstanding protein, vitamin, mineral and nutraceutical content. The leaves, flowers and seed coat of quinoa contain triterpenoid saponins, which impart bitterness to the grain and make them unpalatable without postharvest removal of the saponins. In this study, we quantified saponin content in quinoa leaves from Ecuadorian sweet and bitter genotypes and assessed the expression of saponin biosynthetic genes in leaf samples elicited with methyl jasmonate. We found saponin accumulation in leaves after MeJA treatment in both ecotypes tested. As no reference genes were available to perform qPCR in quinoa, we mined publicly available RNA-Seq data for orthologs of 22 genes known to be stably expressed in Arabidopsis thaliana using geNorm, NormFinder and BestKeeper algorithms. The quinoa ortholog of At2g28390 (Monensin Sensitivity 1, MON1) was stably expressed and chosen as a suitable reference gene for qPCR analysis. Candidate saponin biosynthesis genes were screened in the quinoa RNA-Seq data and subsequent functional characterization in yeast led to the identification of CqbAS1, CqCYP716A78 and CqCYP716A79. These genes were found to be induced by MeJA, suggesting this phytohormone might also modulate saponin biosynthesis in quinoa leaves. Knowledge of the saponin biosynthesis and its regulation in quinoa may aid the further development of sweet cultivars that do not require postharvest processing. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Elucidation and in planta reconstitution of the parthenolide biosynthetic pathway

    DEFF Research Database (Denmark)

    Liu, Qing; Manzano, David; Tanić, Nikola

    2014-01-01

    Parthenolide, the main bioactive compound of the medicinal plant feverfew (Tanacetum parthenium), is a promising anti-cancer drug. However, the biosynthetic pathway of parthenolide has not been elucidated yet. Here we report on the isolation and characterization of all the genes from feverfew tha...

  4. Novel Phl-producing genotypes of finger millet rhizosphere associated pseudomonads and assessment of their functional and genetic diversity.

    Science.gov (United States)

    Sekar, Jegan; Prabavathy, Vaiyapuri Ramalingam

    2014-07-01

    Genetic diversity of phlD gene, an essential gene in the biosynthesis of 2,4-diacetylphloroglucinol, was studied by restriction fragment length polymorphism (RFLP) in 20 Phl-producing pseudomonads isolated from finger millet rhizosphere. RFLP analysis of phlD gene displayed three patterns with HaeIII and TaqI enzymes. phlD gene sequence closely correlated with RFLP results and revealed the existence of three new genotypes G, H and I. Further, the phylogenetic and concatenated sequence analysis of the 16S rRNA, rpoB, gyrB, rpoD genes supported the hypothesis that these genotypes G, H and I were different from reported genotypes A-F. In all phylogenetic studies, the genotype G formed a distant clade from the groups of Pseudomonas putida and P. aeruginosa (sensu strictu), but the groups H and I were closely related to P. aeruginosa/P. stutzeri group. The Phl-producing pseudomonads exhibited antagonistic activity against Pyricularia grisea (TN508), Gaeumannomyces graminis (DSM1463), Fusarium oxysporum (DSM62297), Xanthomonas campestris (DSM3586) and Erwinia persicina (HMGU155). In addition, these strains exhibited various plant growth-promoting traits. In conclusion, this study displays the existence of novel Phl-producing pseudomonads genotypes G, H and I from finger millet rhizosphere, which formed taxonomically outward phylogenetic lineage from the groups of P. putida and P. aeruginosa (sensu strictu). © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  5. Sequencing, physical organization and kinetic expression of the patulin biosynthetic gene cluster from Penicillium expansum

    International Nuclear Information System (INIS)

    Tannous, J.; El Khoury, R.; El Khoury, A.; Lteif, R.; Snini, S.; Lippi, Y.; Oswald, I.; Olivier, P.; Atoui, A.

    2014-01-01

    Patulin is a polyketide-derived mycotoxin produced by numerous filamentous fungi. Among them, Penicillium expansum is by far the most problematic species. This fungus is a destructive phytopathogen capable of growing on fruit, provoking the blue mold decay of apples and producing significant amounts of patulin. The biosynthetic pathway of this mycotoxin is chemically well-characterized, but its genetic bases remain largely unknown with only few characterized genes in less economic relevant species. The present study consisted of the identification and positional organization of the patulin gene cluster in P. expansum strain NRRL 35695. Several amplification reactions were performed with degenerative primers that were designed based on sequences from the orthologous genes available in other species. An improved genome Walking approach was used in order to sequence the remaining adjacent genes of the cluster. RACE-PCR was also carried out from mRNAs to determine the start and stop codons of the coding sequences. The patulin gene cluster in P. expansum consists of 15 genes in the following order: patH, patG, patF, patE, patD, patC, patB, patA, patM, patN, patO, patL, patI, patJ, and patK. These genes share 60–70% of identity with orthologous genes grouped differently, within a putative patulin cluster described in a non-producing strain of Aspergillus clavatus. The kinetics of patulin cluster genes expression was studied under patulin-permissive conditions (natural apple-based medium) and patulin-restrictive conditions (Eagle's minimal essential medium), and demonstrated a significant association between gene expression and patulin production. In conclusion, the sequence of the patulin cluster in P. expansum constitutes a key step for a better understanding of themechanisms leading to patulin production in this fungus. It will allow the role of each gene to be elucidated, and help to define strategies to reduce patulin production in apple-based products

  6. Enrichment of provitamin A content in wheat (Triticum aestivum L.) by introduction of the bacterial carotenoid biosynthetic genes CrtB and CrtI.

    Science.gov (United States)

    Wang, Cheng; Zeng, Jian; Li, Yin; Hu, Wei; Chen, Ling; Miao, Yingjie; Deng, Pengyi; Yuan, Cuihong; Ma, Cheng; Chen, Xi; Zang, Mingli; Wang, Qiong; Li, Kexiu; Chang, Junli; Wang, Yuesheng; Yang, Guangxiao; He, Guangyuan

    2014-06-01

    Carotenoid content is a primary determinant of wheat nutritional value and affects its end-use quality. Wheat grains contain very low carotenoid levels and trace amounts of provitamin A content. In order to enrich the carotenoid content in wheat grains, the bacterial phytoene synthase gene (CrtB) and carotene desaturase gene (CrtI) were transformed into the common wheat cultivar Bobwhite. Expression of CrtB or CrtI alone slightly increased the carotenoid content in the grains of transgenic wheat, while co-expression of both genes resulted in a darker red/yellow grain phenotype, accompanied by a total carotenoid content increase of approximately 8-fold achieving 4.76 μg g(-1) of seed dry weight, a β-carotene increase of 65-fold to 3.21 μg g(-1) of seed dry weight, and a provitamin A content (sum of α-carotene, β-carotene, and β-cryptoxanthin) increase of 76-fold to 3.82 μg g(-1) of seed dry weight. The high provitamin A content in the transgenic wheat was stably inherited over four generations. Quantitative PCR analysis revealed that enhancement of provitamin A content in transgenic wheat was also a result of the highly coordinated regulation of endogenous carotenoid biosynthetic genes, suggesting a metabolic feedback regulation in the wheat carotenoid biosynthetic pathway. These transgenic wheat lines are not only valuable for breeding wheat varieties with nutritional benefits for human health but also for understanding the mechanism regulating carotenoid biosynthesis in wheat endosperm. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  7. Accumulation of Kaempferitrin and Expression of Phenyl-Propanoid Biosynthetic Genes in Kenaf (Hibiscus cannabinus

    Directory of Open Access Journals (Sweden)

    Shicheng Zhao

    2014-10-01

    Full Text Available Kenaf (Hibiscus cannabinus is cultivated worldwide for its fiber; however, the medicinal properties of this plant are currently attracting increasing attention. In this study, we investigated the expression levels of genes involved in the biosynthesis of kaempferitrin, a compound with many biological functions, in different kenaf organs. We found that phenylalanine ammonia lyase (HcPAL was more highly expressed in stems than in other organs. Expression levels of cinnamate 4-hydroxylase (HcC4H and 4-coumarate-CoA ligase (Hc4CL were highest in mature leaves, followed by stems and young leaves, and lowest in roots and mature flowers. The expression of chalcone synthase (HcCHS, chalcone isomerase (HcCHI, and flavone 3-hydroxylase (HcF3H was highest in young flowers, whereas that of flavone synthase (HcFLS was highest in leaves. An analysis of kaempferitrin accumulation in the different organs of kenaf revealed that the accumulation of this compound was considerably higher (>10-fold in leaves than in other organs. On the basis of a comparison of kaempferitrin contents with the expression levels of different genes in different organs, we speculate that HcFLS plays an important regulatory role in the kaempferitrin biosynthetic pathway in kenaf.

  8. Accumulation of kaempferitrin and expression of phenyl-propanoid biosynthetic genes in kenaf (Hibiscus cannabinus).

    Science.gov (United States)

    Zhao, Shicheng; Li, Xiaohua; Cho, Dong Ha; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Park, Sang Un

    2014-10-23

    Kenaf (Hibiscus cannabinus) is cultivated worldwide for its fiber; however, the medicinal properties of this plant are currently attracting increasing attention. In this study, we investigated the expression levels of genes involved in the biosynthesis of kaempferitrin, a compound with many biological functions, in different kenaf organs. We found that phenylalanine ammonia lyase (HcPAL) was more highly expressed in stems than in other organs. Expression levels of cinnamate 4-hydroxylase (HcC4H) and 4-coumarate-CoA ligase (Hc4CL) were highest in mature leaves, followed by stems and young leaves, and lowest in roots and mature flowers. The expression of chalcone synthase (HcCHS), chalcone isomerase (HcCHI), and flavone 3-hydroxylase (HcF3H) was highest in young flowers, whereas that of flavone synthase (HcFLS) was highest in leaves. An analysis of kaempferitrin accumulation in the different organs of kenaf revealed that the accumulation of this compound was considerably higher (>10-fold) in leaves than in other organs. On the basis of a comparison of kaempferitrin contents with the expression levels of different genes in different organs, we speculate that HcFLS plays an important regulatory role in the kaempferitrin biosynthetic pathway in kenaf.

  9. Cell wall composition and lignin biosynthetic gene expression along a developmental gradient in an Australian sugarcane cultivar

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    William P. Bewg

    2017-12-01

    Full Text Available Sugarcane bagasse is an abundant source of lignocellulosic material for bioethanol production. Utilisation of bagasse for biofuel production would be environmentally and economically beneficial, but the recalcitrance of lignin continues to provide a challenge. Further understanding of lignin production in specific cultivars will provide a basis for modification of genomes for the production of phenotypes with improved processing characteristics. Here we evaluated the expression profile of lignin biosynthetic genes and the cell wall composition along a developmental gradient in KQ228 sugarcane. The expression levels of nine lignin biosynthesis genes were quantified in five stem sections of increasing maturity and in root tissue. Two distinct expression patterns were seen. The first saw highest gene expression in the youngest tissue, with expression decreasing as tissue matured. The second pattern saw little to no change in transcription levels across the developmental gradient. Cell wall compositional analysis of the stem sections showed total lignin content to be significantly higher in more mature tissue than in the youngest section assessed. There were no changes in structural carbohydrates across developmental sections. These gene expression and cell wall compositional patterns can be used, along with other work in grasses, to inform biotechnological approaches to crop improvement for lignocellulosic biofuel production.

  10. Endophytic actinobacteria: Diversity, secondary metabolism and mechanisms to unsilence biosynthetic gene clusters.

    Science.gov (United States)

    Dinesh, Raghavan; Srinivasan, Veeraraghavan; T E, Sheeja; Anandaraj, Muthuswamy; Srambikkal, Hamza

    2017-09-01

    Endophytic actinobacteria, which reside in the inner tissues of host plants, are gaining serious attention due to their capacity to produce a plethora of secondary metabolites (e.g. antibiotics) possessing a wide variety of biological activity with diverse functions. This review encompasses the recent reports on endophytic actinobacterial species diversity, in planta habitats and mechanisms underlying their mode of entry into plants. Besides, their metabolic potential, novel bioactive compounds they produce and mechanisms to unravel their hidden metabolic repertoire by activation of cryptic or silent biosynthetic gene clusters (BGCs) for eliciting novel secondary metabolite production are discussed. The study also reviews the classical conservative techniques (chemical/biological/physical elicitation, co-culturing) as well as modern microbiology tools (e.g. next generation sequencing) that are being gainfully employed to uncover the vast hidden scaffolds for novel secondary metabolites produced by these endophytes, which would subsequently herald a revolution in drug engineering. The potential role of these endophytes in the agro-environment as promising biological candidates for inhibition of phytopathogens and the way forward to thoroughly exploit this unique microbial community by inducing expression of cryptic BGCs for encoding unseen products with novel therapeutic properties are also discussed.

  11. Enhancement of Nucleoside Production in Hirsutella sinensis Based on Biosynthetic Pathway Analysis

    Science.gov (United States)

    Liu, Zhi-Qiang; Zhang, Bo; Lin, Shan; Baker, Peter James; Chen, Mao-Sheng; Xue, Ya-Ping; Wu, Hui; Xu, Feng; Yuan, Shui-Jin; Teng, Yi; Wu, Ling-Fang

    2017-01-01

    To enhance nucleoside production in Hirsutella sinensis, the biosynthetic pathways of purine and pyrimidine nucleosides were constructed and verified. The differential expression analysis showed that purine nucleoside phosphorylase, inosine monophosphate dehydrogenase, and guanosine monophosphate synthase genes involved in purine nucleotide biosynthesis were significantly upregulated 16.56-fold, 8-fold, and 5.43-fold, respectively. Moreover, dihydroorotate dehydrogenase, uridine nucleosidase, uridine/cytidine monophosphate kinase, and inosine triphosphate pyrophosphatase genes participating in pyrimidine nucleoside biosynthesis were upregulated 4.53-fold, 10.63-fold, 4.26-fold, and 5.98-fold, respectively. To enhance the nucleoside production, precursors for synthesis of nucleosides were added based on the analysis of biosynthetic pathways. Uridine and cytidine contents, respectively, reached 5.04 mg/g and 3.54 mg/g when adding 2 mg/mL of ribose, resulting in an increase of 28.6% and 296% compared with the control, respectively. Meanwhile, uridine and cytidine contents, respectively, reached 10.83 mg/g 2.12 mg/g when adding 0.3 mg/mL of uracil, leading to an increase of 176.3% and 137.1%, respectively. This report indicated that fermentation regulation was an effective way to enhance the nucleoside production in H. sinensis based on biosynthetic pathway analysis. PMID:29333435

  12. Global analysis of biosynthetic gene clusters reveals vast potential of secondary metabolite production in Penicillium species

    DEFF Research Database (Denmark)

    Nielsen, Jens Christian; Grijseels, Sietske; Prigent, Sylvain

    2017-01-01

    Filamentous fungi produce a wide range of bioactive compounds with important pharmaceutical applications, such as antibiotic penicillins and cholesterol-lowering statins. However, less attention has been paid to fungal secondary metabolites compared to those from bacteria. In this study, we...... sequenced the genomes of 9 Penicillium species and, together with 15 published genomes, we investigated the secondary metabolism of Penicillium and identified an immense, unexploited potential for producing secondary metabolites by this genus. A total of 1,317 putative biosynthetic gene clusters (BGCs) were......-referenced the predicted pathways with published data on the production of secondary metabolites and experimentally validated the production of antibiotic yanuthones in Penicillia and identified a previously undescribed compound from the yanuthone pathway. This study is the first genus-wide analysis of the genomic...

  13. Seasonal alteration in amounts of lignans and their glucosides and gene expression of the relevant biosynthetic enzymes in the Forsythia suspense leaf.

    Science.gov (United States)

    Morimoto, Kinuyo; Satake, Honoo

    2013-01-01

    Lignans of Forsythia spp. are essential components of various Chinese medicines and health diets. However, the seasonal alteration in lignan amounts and the gene expression profile of lignan-biosynthetic enzymes has yet to be investigated. In this study, we have assessed seasonal alteration in amounts of major lignans, such as pinoresinol, matairesinol, and arctigenin, and examined the gene expression profile of pinoresinol/lariciresinol reductase (PLR), pinoresinol-glucosylating enzyme (UGT71A18), and secoisolariciresinol dehydrogenase (SIRD) in the leaf of Forsythia suspense from April to November. All of the lignans in the leaf continuously increased from April to June, reached the maximal level in June, and then decreased. Ninety percent of pinoresinol and matairesinol was converted into glucosides, while approximately 50% of arctigenin was aglycone. PLR was stably expressed from April to August, whereas the PLR expression was not detected from September to November. In contrast, the UGT71A18 expression was found from August to November, but not from April to July. The SIRD expression was prominent from April to May, not detected in June to July, and then increased again from September to November. These expression profiles of the lignan-synthetic enzymes are largely compatible with the alteration in lignan contents. Furthermore, such seasonal lignan profiles are in good agreement with the fact that the Forsythia leaves for Chinese medicinal tea are harvested in June. This is the first report on seasonal alteration in lignans and the relevant biosynthetic enzyme genes in the leaf of Forsythia species.

  14. Differential gene expression in liver and small intestine from lactating rats compared to age-matched virgin controls detects increased mRNA of cholesterol biosynthetic genes

    Directory of Open Access Journals (Sweden)

    Jungsuwadee Paiboon

    2011-02-01

    Full Text Available Abstract Background Lactation increases energy demands four- to five-fold, leading to a two- to three-fold increase in food consumption, requiring a proportional adjustment in the ability of the lactating dam to absorb nutrients and to synthesize critical biomolecules, such as cholesterol, to meet the dietary needs of both the offspring and the dam. The size and hydrophobicity of the bile acid pool increases during lactation, implying an increased absorption and disposition of lipids, sterols, nutrients, and xenobiotics. In order to investigate changes at the transcriptomics level, we utilized an exon array and calculated expression levels to investigate changes in gene expression in the liver, duodenum, jejunum, and ileum of lactating dams when compared against age-matched virgin controls. Results A two-way mixed models ANOVA was applied to detect differentially expressed genes. Significance calls were defined as a p Cyp7a1, which catalyzes the rate limiting step in the bile acid biosynthetic pathway, was also significantly increased in liver. In addition, decreased levels of mRNA associated with T-cell signaling were found in the jejunum and ileum. Several members of the Solute Carrier (SLC and Adenosine Triphosphate Binding Cassette (ABC superfamilies of membrane transporters were found to be differentially expressed; these genes may play a role in differences in nutrient and xenobiotic absorption and disposition. mRNA expression of SLC39a4_predicted, a zinc transporter, was increased in all tissues, suggesting that it is involved in increased zinc uptake during lactation. Microarray data are available through GEO under GSE19175. Conclusions We detected differential expression of mRNA from several pathways in lactating dams, including upregulation of the cholesterol biosynthetic pathway in liver and intestine, consistent with Srebp activation. Differential T-Cell signaling in the two most distal regions of the small intestine (ileum and

  15. Perturbations in the Photosynthetic Pigment Status Result in Photooxidation-Induced Crosstalk between Carotenoid and Porphyrin Biosynthetic Pathways

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    Joon-Heum Park

    2017-11-01

    Full Text Available Possible crosstalk between the carotenoid and porphyrin biosynthetic pathways under photooxidative conditions was investigated by using their biosynthetic inhibitors, norflurazon (NF and oxyfluorfen (OF. High levels of protoporphyrin IX (Proto IX accumulated in rice plants treated with OF, whereas Proto IX decreased in plants treated with NF. Both NF and OF treatments resulted in greater decreases in MgProto IX, MgProto IX methyl ester, and protochlorophyllide. Activities and transcript levels of most porphyrin biosynthetic enzymes, particularly in the Mg-porphyrin branch, were greatly down-regulated in NF and OF plants. In contrast, the transcript levels of GSA, PPO1, and CHLD as well as FC2 and HO2 were up-regulated in NF-treated plants, while only moderate increases in FC2 and HO2 were observed in the early stage of OF treatment. Phytoene, antheraxanthin, and zeaxanthin showed high accumulation in NF-treated plants, whereas other carotenoid intermediates greatly decreased. Transcript levels of carotenoid biosynthetic genes, PSY1 and PDS, decreased in response to NF and OF, whereas plants in the later stage of NF treatment exhibited up-regulation of BCH and VDE as well as recovery of PDS. However, perturbed porphyrin biosynthesis by OF did not noticeably influence levels of carotenoid metabolites, regardless of the strong down-regulation of carotenoid biosynthetic genes. Both NF and OF plants appeared to provide enhanced protection against photooxidative damage, not only by scavenging of Mg-porphyrins, but also by up-regulating FC2, HO2, and Fe-chelatase, particularly with increased levels of zeaxanthin via up-regulation of BCH and VDE in NF plants. On the other hand, the up-regulation of GSA, PPO1, and CHLD under inhibition of carotenogenic flux may be derived from the necessity to recover impaired chloroplast biogenesis during photooxidative stress. Our study demonstrates that perturbations in carotenoid and porphyrin biosynthesis coordinate

  16. Perturbations in the Photosynthetic Pigment Status Result in Photooxidation-Induced Crosstalk between Carotenoid and Porphyrin Biosynthetic Pathways.

    Science.gov (United States)

    Park, Joon-Heum; Tran, Lien H; Jung, Sunyo

    2017-01-01

    Possible crosstalk between the carotenoid and porphyrin biosynthetic pathways under photooxidative conditions was investigated by using their biosynthetic inhibitors, norflurazon (NF) and oxyfluorfen (OF). High levels of protoporphyrin IX (Proto IX) accumulated in rice plants treated with OF, whereas Proto IX decreased in plants treated with NF. Both NF and OF treatments resulted in greater decreases in MgProto IX, MgProto IX methyl ester, and protochlorophyllide. Activities and transcript levels of most porphyrin biosynthetic enzymes, particularly in the Mg-porphyrin branch, were greatly down-regulated in NF and OF plants. In contrast, the transcript levels of GSA, PPO1 , and CHLD as well as FC2 and HO2 were up-regulated in NF-treated plants, while only moderate increases in FC2 and HO2 were observed in the early stage of OF treatment. Phytoene, antheraxanthin, and zeaxanthin showed high accumulation in NF-treated plants, whereas other carotenoid intermediates greatly decreased. Transcript levels of carotenoid biosynthetic genes, PSY1 and PDS , decreased in response to NF and OF, whereas plants in the later stage of NF treatment exhibited up-regulation of BCH and VDE as well as recovery of PDS . However, perturbed porphyrin biosynthesis by OF did not noticeably influence levels of carotenoid metabolites, regardless of the strong down-regulation of carotenoid biosynthetic genes. Both NF and OF plants appeared to provide enhanced protection against photooxidative damage, not only by scavenging of Mg - porphyrins, but also by up-regulating FC2, HO2 , and Fe-chelatase, particularly with increased levels of zeaxanthin via up-regulation of BCH and VDE in NF plants. On the other hand, the up-regulation of GSA, PPO1 , and CHLD under inhibition of carotenogenic flux may be derived from the necessity to recover impaired chloroplast biogenesis during photooxidative stress. Our study demonstrates that perturbations in carotenoid and porphyrin biosynthesis coordinate the

  17. Heterologous expression and transcript analysis of gibberellin biosynthetic genes of grasses reveals novel functionality in the GA3ox family.

    Science.gov (United States)

    Pearce, Stephen; Huttly, Alison K; Prosser, Ian M; Li, Yi-dan; Vaughan, Simon P; Gallova, Barbora; Patil, Archana; Coghill, Jane A; Dubcovsky, Jorge; Hedden, Peter; Phillips, Andrew L

    2015-06-05

    The gibberellin (GA) pathway plays a central role in the regulation of plant development, with the 2-oxoglutarate-dependent dioxygenases (2-ODDs: GA20ox, GA3ox, GA2ox) that catalyse the later steps in the biosynthetic pathway of particularly importance in regulating bioactive GA levels. Although GA has important impacts on crop yield and quality, our understanding of the regulation of GA biosynthesis during wheat and barley development remains limited. In this study we identified or assembled genes encoding the GA 2-ODDs of wheat, barley and Brachypodium distachyon and characterised the wheat genes by heterologous expression and transcript analysis. The wheat, barley and Brachypodium genomes each contain orthologous copies of the GA20ox, GA3ox and GA2ox genes identified in rice, with the exception of OsGA3ox1 and OsGA2ox5 which are absent in these species. Some additional paralogs of 2-ODD genes were identified: notably, a novel gene in the wheat B genome related to GA3ox2 was shown to encode a GA 1-oxidase, named as TaGA1ox-B1. This enzyme is likely to be responsible for the abundant 1β-hydroxylated GAs present in developing wheat grains. We also identified a related gene in barley, located in a syntenic position to TaGA1ox-B1, that encodes a GA 3,18-dihydroxylase which similarly accounts for the accumulation of unusual GAs in barley grains. Transcript analysis showed that some paralogs of the different classes of 2-ODD were expressed mainly in a single tissue or at specific developmental stages. In particular, TaGA20ox3, TaGA1ox1, TaGA3ox3 and TaGA2ox7 were predominantly expressed in developing grain. More detailed analysis of grain-specific gene expression showed that while the transcripts of biosynthetic genes were most abundant in the endosperm, genes encoding inactivation and signalling components were more highly expressed in the seed coat and pericarp. The comprehensive expression and functional characterisation of the multigene families encoding the 2-ODD

  18. Targeted Gene Disruption of the Cyclo (L-Phe, L-Pro Biosynthetic Pathway in Streptomyces sp. US24 Strain

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    Samiha Sioud

    2007-01-01

    Full Text Available We have previously isolated a new actinomycete strain from Tunisian soil called Streptomyces sp. US24, and have shown that it produces two bioactive molecules including a Cyclo (L-Phe, L-Pro diketopiperazine (DKP. To identify the structural genes responsible for the synthesis of this DKP derivative, a PCR amplification (696 bp was carried out using the Streptomyces sp. US24 genomic DNA as template and two degenerate oligonucleotides designed by analogy with genes encoding peptide synthetases (NRPS. The detection of DKP derivative biosynthetic pathway of the Streptomyces sp. US24 strain was then achieved by gene disruption via homologous recombination using a suicide vector derived from the conjugative plasmid pSET152 and containing the PCR product. Chromatography analysis, biological tests and spectroscopic studies of supernatant cultures of the wild-type Streptomyces sp. US24 strain and three mutants obtained by this gene targeting disruption approach showed that the amplified DNA fragment is required for Cyclo (L-Phe, L-Pro biosynthesis in Streptomyces sp. US24 strain. This DKP derivative seems to be produced either directly via a nonribosomal pathway or as a side product in the course of nonribosomal synthesis of a longer peptide.

  19. Genetic analysis of the capsular biosynthetic locus from all 90 pneumococcal serotypes.

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    Stephen D Bentley

    2006-03-01

    Full Text Available Several major invasive bacterial pathogens are encapsulated. Expression of a polysaccharide capsule is essential for survival in the blood, and thus for virulence, but also is a target for host antibodies and the basis for effective vaccines. Encapsulated species typically exhibit antigenic variation and express one of a number of immunochemically distinct capsular polysaccharides that define serotypes. We provide the sequences of the capsular biosynthetic genes of all 90 serotypes of Streptococcus pneumoniae and relate these to the known polysaccharide structures and patterns of immunological reactivity of typing sera, thereby providing the most complete understanding of the genetics and origins of bacterial polysaccharide diversity, laying the foundations for molecular serotyping. This is the first time, to our knowledge, that a complete repertoire of capsular biosynthetic genes has been available, enabling a holistic analysis of a bacterial polysaccharide biosynthesis system. Remarkably, the total size of alternative coding DNA at this one locus exceeds 1.8 Mbp, almost equivalent to the entire S. pneumoniae chromosomal complement.

  20. Transcription factor VdCmr1 is required for pigment production, protection from UV irradiation, and regulates expression of melanin biosynthetic genes in Verticillium dahliae.

    Science.gov (United States)

    Wang, Yonglin; Hu, Xiaoping; Fang, Yulin; Anchieta, Amy; Goldman, Polly H; Hernandez, Gustavo; Klosterman, Steven J

    2018-04-01

    Verticillium dahliae is a soilborne fungus that causes vascular wilt diseases on numerous plant species worldwide. The production of darkly melanized microsclerotia is crucial in the disease cycle of V. dahliae, as these structures allow for long-term survival in soil. Previously, transcriptomic and genomic analysis identified a cluster of genes in V. dahliae that encodes some dihydroxynaphthalene (DHN) melanin biosynthetic pathway homologues found in related fungi. In this study, we explored the roles of cluster-specific transcription factor VdCmr1, as well as two other genes within the cluster encoding a polyketide synthase (VdPKS1) and a laccase (VdLac1), enzymes at initial and endpoint steps in DHN melanin production. The results revealed that VdCmr1 and VdPKS1 are required for melanin production, but neither is required for microsclerotia production. None of the three genes were required for pathogenesis on tobacco and lettuce. Exposure of ΔVdCmr1 and wild-type strains to UV irradiation, or to high temperature (40 °C), revealed an approx. 50 % reduction of survival in the ΔVdCmr1 strain, relative to the wild-type strain, in response to either condition. Expression profiles revealed that expression of some melanin biosynthetic genes are in part dependent on VdCmr1. Combined data indicate VdCmr1 is a key regulator of melanin biosynthesis, and that via regulation of melanogenesis, VdCmr1 affects survival of V. dahliae in response to abiotic threats. We conclude with a model showing regulation of VdCmr1 by a high osmolarity glycerol response (Hog)-type MAP kinase pathway.

  1. Giant linear plasmids in Streptomyces: a treasure trove of antibiotic biosynthetic clusters.

    Science.gov (United States)

    Kinashi, Haruyasu

    2011-01-01

    Many giant linear plasmids have been isolated from Streptomyces by using pulsed-field gel electrophoresis and some of them were found to carry an antibiotic biosynthetic cluster(s); SCP1 carries biosynthetic genes for methylenomycin, pSLA2-L for lankacidin and lankamycin, and pKSL for lasalocid and echinomycin. Accumulated data suggest that giant linear plasmids have played critical roles in genome evolution and horizontal transfer of secondary metabolism. In this review, I summarize typical examples of giant linear plasmids whose involvement in antibiotic production has been studied in some detail, emphasizing their finding processes and interaction with the host chromosomes. A hypothesis on horizontal transfer of secondary metabolism involving giant linear plasmids is proposed at the end.

  2. Variation in fumonisin and ochratoxin production associated with differences in biosynthetic gene content in Aspergillus niger and A. welwitschiae isolates from multiple crop and geographic origins

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    Antonia Susca

    2016-09-01

    Full Text Available The fungi Aspergillus niger and A. welwitschiae are morphologically indistinguishable species used for industrial fermentation and for food and beverage production. The fungi also occur widely on food crops. Concerns about their safety have arisen with the discovery that some isolates of both species produce fumonisin (FB and ochratoxin A (OTA mycotoxins. Here, we examined FB and OTA production as well as the presence of genes responsible for synthesis of the mycotoxins in a collection of 92 A. niger/A. welwitschiae isolates from multiple crop and geographic origins. The results indicate that i isolates of both species differed in ability to produce the mycotoxins; ii FB-nonproducing isolates of A. niger had an intact fumonisin biosynthetic gene (fum cluster; iii FB-nonproducing isolates of A. welwitschiae exhibited multiple patterns of fum gene deletion; and iv OTA-nonproducing isolates of both species lacked the ochratoxin A biosynthetic gene (ota cluster. Analysis of genome sequence data revealed a single pattern of ota gene deletion in the two species. Phylogenetic analysis suggest that the simplest explanation for this is that ota cluster deletion occurred in a common ancestor of A. niger and A. welwitschiae, and subsequently both the intact and deleted cluster were retained as alternate alleles during divergence of the ancestor into descendent species. Finally, comparison of results from this and previous studies indicate that a majority of A. niger isolates and a minority of A. welwitschiae isolates can produce FBs, whereas a minority of isolates of both species produce OTA. The comparison also suggested that the relative abundance of each species and frequency of FB/OTA-producing isolates can vary with crop and/or geographic origin.

  3. Genomic characterization of a new endophytic Streptomyces kebangsaanensis identifies biosynthetic pathway gene clusters for novel phenazine antibiotic production

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    Juwairiah Remali

    2017-11-01

    Full Text Available Background Streptomyces are well known for their capability to produce many bioactive secondary metabolites with medical and industrial importance. Here we report a novel bioactive phenazine compound, 6-((2-hydroxy-4-methoxyphenoxy carbonyl phenazine-1-carboxylic acid (HCPCA extracted from Streptomyces kebangsaanensis, an endophyte isolated from the ethnomedicinal Portulaca oleracea. Methods The HCPCA chemical structure was determined using nuclear magnetic resonance spectroscopy. We conducted whole genome sequencing for the identification of the gene cluster(s believed to be responsible for phenazine biosynthesis in order to map its corresponding pathway, in addition to bioinformatics analysis to assess the potential of S. kebangsaanensis in producing other useful secondary metabolites. Results The S. kebangsaanensis genome comprises an 8,328,719 bp linear chromosome with high GC content (71.35% consisting of 12 rRNA operons, 81 tRNA, and 7,558 protein coding genes. We identified 24 gene clusters involved in polyketide, nonribosomal peptide, terpene, bacteriocin, and siderophore biosynthesis, as well as a gene cluster predicted to be responsible for phenazine biosynthesis. Discussion The HCPCA phenazine structure was hypothesized to derive from the combination of two biosynthetic pathways, phenazine-1,6-dicarboxylic acid and 4-methoxybenzene-1,2-diol, originated from the shikimic acid pathway. The identification of a biosynthesis pathway gene cluster for phenazine antibiotics might facilitate future genetic engineering design of new synthetic phenazine antibiotics. Additionally, these findings confirm the potential of S. kebangsaanensis for producing various antibiotics and secondary metabolites.

  4. Reconstitution of Biosynthetic Machinery for the Synthesis of the Highly Elaborated Indole Diterpene Penitrem

    DEFF Research Database (Denmark)

    Liu, Chengwei; Tagami, Koichi; Minami, Atsushi

    2015-01-01

    KULNJ). Importantly, without conventional gene disruption, reconstitution of the biosynthetic machinery provided sufficient data to determine the pathway. It was thus demonstrated that the Aspergillus oryzae reconstitution system is a powerful method for studying the biosynthesis of complex natural products....

  5. Dual biosynthetic pathways to phytosterol via cycloartenol and lanosterol in Arabidopsis.

    Science.gov (United States)

    Ohyama, Kiyoshi; Suzuki, Masashi; Kikuchi, Jun; Saito, Kazuki; Muranaka, Toshiya

    2009-01-20

    The differences between the biosynthesis of sterols in higher plants and yeast/mammals are believed to originate at the cyclization step of oxidosqualene, which is cyclized to cycloartenol in higher plants and lanosterol in yeast/mammals. Recently, lanosterol synthase genes were identified from dicotyledonous plant species including Arabidopsis, suggesting that higher plants possess dual biosynthetic pathways to phytosterols via lanosterol, and through cycloartenol. To identify the biosynthetic pathway to phytosterol via lanosterol, and to reveal the contributions to phytosterol biosynthesis via each cycloartenol and lanosterol, we performed feeding experiments by using [6-(13)C(2)H(3)]mevalonate with Arabidopsis seedlings. Applying (13)C-{(1)H}{(2)H} nuclear magnetic resonance (NMR) techniques, the elucidation of deuterium on C-19 behavior of phytosterol provided evidence that small amounts of phytosterol were biosynthesized via lanosterol. The levels of phytosterol increased on overexpression of LAS1, and phytosterols derived from lanosterol were not observed in a LAS1-knockout plant. This is direct evidence to indicate that the biosynthetic pathway for phytosterol via lanosterol exists in plant cells. We designate the biosynthetic pathway to phytosterols via lanosterol "the lanosterol pathway." LAS1 expression is reported to be induced by the application of jasmonate and is thought to have evolved from an ancestral cycloartenol synthase to a triterpenoid synthase, such as beta-amyrin synthase and lupeol synthase. Considering this background, the lanosterol pathway may contribute to the biosynthesis of not only phytosterols, but also steroids as secondary metabolites.

  6. Sequence diversity and differential expression of major phenylpropanoid-flavonoid biosynthetic genes among three mango varieties.

    Science.gov (United States)

    Hoang, Van L T; Innes, David J; Shaw, P Nicholas; Monteith, Gregory R; Gidley, Michael J; Dietzgen, Ralf G

    2015-07-30

    Mango fruits contain a broad spectrum of phenolic compounds which impart potential health benefits; their biosynthesis is catalysed by enzymes in the phenylpropanoid-flavonoid (PF) pathway. The aim of this study was to reveal the variability in genes involved in the PF pathway in three different mango varieties Mangifera indica L., a member of the family Anacardiaceae: Kensington Pride (KP), Irwin (IW) and Nam Doc Mai (NDM) and to determine associations with gene expression and mango flavonoid profiles. A close evolutionary relationship between mango genes and those from the woody species poplar of the Salicaceae family (Populus trichocarpa) and grape of the Vitaceae family (Vitis vinifera), was revealed through phylogenetic analysis of PF pathway genes. We discovered 145 SNPs in total within coding sequences with an average frequency of one SNP every 316 bp. Variety IW had the highest SNP frequency (one SNP every 258 bp) while KP and NDM had similar frequencies (one SNP every 369 bp and 360 bp, respectively). The position in the PF pathway appeared to influence the extent of genetic diversity of the encoded enzymes. The entry point enzymes phenylalanine lyase (PAL), cinnamate 4-mono-oxygenase (C4H) and chalcone synthase (CHS) had low levels of SNP diversity in their coding sequences, whereas anthocyanidin reductase (ANR) showed the highest SNP frequency followed by flavonoid 3'-hydroxylase (F3'H). Quantitative PCR revealed characteristic patterns of gene expression that differed between mango peel and flesh, and between varieties. The combination of mango expressed sequence tags and availability of well-established reference PF biosynthetic genes from other plant species allowed the identification of coding sequences of genes that may lead to the formation of important flavonoid compounds in mango fruits and facilitated characterisation of single nucleotide polymorphisms between varieties. We discovered an association between the extent of sequence variation and

  7. Targeting fumonisin biosynthetic genes

    Science.gov (United States)

    The fungus Fusarium is an agricultural problem because it can cause disease on most crop plants and can contaminate crops with mycotoxins. There is considerable variation in the presence/absence and genomic location of gene clusters responsible for synthesis of mycotoxins and other secondary metabol...

  8. Mutational studies of putative biosynthetic genes for the cyanobacterial sunscreen scytonemin in Nostoc punctiforme ATCC 29133

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    Daniela eFerreira

    2016-05-01

    Full Text Available The heterocyclic indole-alkaloid scytonemin is a sunscreen found exclusively among cyanobacteria. An 18-gene cluster is responsible for scytonemin production in Nostoc punctiforme ATCC 29133. The upstream genes scyABCDEF in the cluster are proposed to be responsible for scytonemin biosynthesis from aromatic amino acid substrates. In vitro studies of ScyA, ScyB and ScyC proved that these enzymes indeed catalyze initial pathway reactions. Here we characterize the role of ScyD, ScyE and ScyF, which were logically predicted to be responsible for late biosynthetic steps, in the biological context of N. punctiforme. In-frame deletion mutants of each were constructed (∆scyD, ∆scyE and ∆scyF and their phenotypes studied. Expectedly, ∆scyE presents a scytoneminless phenotype, but no accumulation of the predicted intermediaries. Surprisingly, ∆scyD retains scytonemin production, implying that it is not required for biosynthesis. Indeed, scyD presents an interesting evolutionary paradox: it likely originated in a duplication event from scyE, and unlike other genes in the operon, it has not been subjected to purifying selection. This would suggest that it is a pseudogene, and yet scyD is highly conserved in the scytonemin operon of cyanobacteria. ∆scyF also retains scytonemin production, albeit exhibiting a reduction of the production yield compared with the wild-type. This indicates that ScyF is not essential but may play an adjuvant role for scytonemin synthesis. Altogether, our findings suggest that these downstream genes are not responsible, as expected, for the late steps of scytonemin synthesis and we must look for those functions elsewhere. These findings are particularly important for biotechnological production of this sunscreen through heterologous expression of its genes in more tractable organisms.

  9. Targeting trichothecene biosynthetic genes

    NARCIS (Netherlands)

    Wei, Songhong; Lee, van der Theo; Verstappen, Els; Gent, van Marga; Waalwijk, Cees

    2017-01-01

    Biosynthesis of trichothecenes requires the involvement of at least 15 genes, most of which have been targeted for PCR. Qualitative PCRs are used to assign chemotypes to individual isolates, e.g., the capacity to produce type A and/or type B trichothecenes. Many regions in the core cluster

  10. Perturbations of carotenoid and tetrapyrrole biosynthetic pathways result in differential alterations in chloroplast function and plastid signaling

    International Nuclear Information System (INIS)

    Park, Joon-Heum; Jung, Sunyo

    2017-01-01

    In this study, we used the biosynthetic inhibitors of carotenoid and tetrapyrrole biosynthetic pathways, norflurazon (NF) and oxyfluorfen (OF), as tools to gain insight into mechanisms of photooxidation in rice plants. NF resulted in bleaching symptom on leaves of the treated plants, whereas OF treatment developed a fast symptom of an apparent necrotic phenotype. Both plants exhibited decreases in photosynthetic efficiency, as indicated by F v /F m . NF caused severe disruption in thylakoid membranes, whereas OF-treated plants exhibited disruption of chloroplast envelope and plasma membrane. Levels of Lhca and Lhcb proteins in photosystem I (PSI) and PSII were reduced by photooxidative stress in NF- and OF-treated plants, with a greater decrease in NF plants. The down-regulation of nuclear-encoded photosynthesis genes Lhcb and rbcS was also found in both NF- and OF-treated plants, whereas plastid-encoded photosynthetic genes including RbcL, PsaC, and PsbD accumulated normally in NF plants but decreased drastically in OF plants. This proposes that the plastids in NF plants retain their potential to develop thylakoid membranes and that photobleaching is mainly controlled by nuclear genes. Distinct photooxidation patterns between NF- and OF-treated plants developed differential signaling, which might enable the plant to coordinate the expression of photosynthetic genes from the nuclear and plastidic genomes. - Highlights: • Two modes of photooxidation by carotenoid and tetrapyrrole biosynthetic inhibitors. • We examine differential alterations in chloroplast function and plastid signaling. • NF and OF cause differential alterations in chloroplast ultrastructure and function. • Photooxidation coordinates photosynthetic gene expression from nucleus and plastid.

  11. Environmental cues induce changes of steviol glycosides contents and transcription of corresponding biosynthetic genes in Stevia rebaudiana.

    Science.gov (United States)

    Yang, Yongheng; Huang, Suzhen; Han, Yulin; Yuan, Haiyan; Gu, Chunsun; Wang, Zhongwei

    2015-01-01

    Plant growth and secondary metabolism are commonly regulated by external cues such as light, temperature and water availability. In this study, the influences of low and high temperatures, dehydration, photoperiods, and different growing stages on the changes of steviol glycosides (SGs) contents and transcription levels of fifteen genes involved in SGs biosynthesis of Stevia rebaudiana Bertoni were examined using HPLC and RT-PCR. The observations showed that the transcript levels of all the fifteen genes were maximum under 25 °C treatment, and the transcription of SrDXS, SrDXR, SrMCT, SrCMK, SrMDS, SrHDS, SrHDR, SrIDI, SrGGDPS, SrCPPS1, SrUGT85C2 and SrUGT76G1 were restrained both in low temperature (15 °C) and high temperature (35 °C). Most genes in SGs biosynthesis pathway exhibited down-regulation in dehydration. To elucidate the effect of photoperiods, the plants were treated by different simulated photoperiods (8 L/16 D, 1 0L/14 D, 14 L/10 D and 16 L/8 D), but no significant transcription changes were observed. In the study of growing stages, there were evident changes of SGs contents, and the transcript levels of all the fifteen genes were minimal in fast growing period, and exhibited evident increase both in flower-bud appearing stage and flowering stage. The obtained results strongly suggest that the effect of environmental cues on steviol glycosides contents and transcription of corresponding biosynthetic genes in S. rebaudiana is significant. It is worth to study deeply. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  12. Designing universal primers for the isolation of DNA sequences encoding Proanthocyanidins biosynthetic enzymes in Crataegus aronia

    Directory of Open Access Journals (Sweden)

    Zuiter Afnan

    2012-08-01

    Full Text Available Abstract Background Hawthorn is the common name of all plant species in the genus Crataegus, which belongs to the Rosaceae family. Crataegus are considered useful medicinal plants because of their high content of proanthocyanidins (PAs and other related compounds. To improve PAs production in Crataegus tissues, the sequences of genes encoding PAs biosynthetic enzymes are required. Findings Different bioinformatics tools, including BLAST, multiple sequence alignment and alignment PCR analysis were used to design primers suitable for the amplification of DNA fragments from 10 candidate genes encoding enzymes involved in PAs biosynthesis in C. aronia. DNA sequencing results proved the utility of the designed primers. The primers were used successfully to amplify DNA fragments of different PAs biosynthesis genes in different Rosaceae plants. Conclusion To the best of our knowledge, this is the first use of the alignment PCR approach to isolate DNA sequences encoding PAs biosynthetic enzymes in Rosaceae plants.

  13. Discovering potential Streptomyces hormone producers by using disruptants of essential biosynthetic genes as indicator strains.

    Science.gov (United States)

    Thao, Nguyen B; Kitani, Shigeru; Nitta, Hiroko; Tomioka, Toshiya; Nihira, Takuya

    2017-10-01

    Autoregulators are low-molecular-weight signaling compounds that control the production of many secondary metabolites in actinomycetes and have been referred to as 'Streptomyces hormones'. Here, potential producers of Streptomyces hormones were investigated in 40 Streptomyces and 11 endophytic actinomycetes. Production of γ-butyrolactone-type (IM-2, VB) and butenolide-type (avenolide) Streptomyces hormones was screened using Streptomyces lavendulae FRI-5 (ΔfarX), Streptomyces virginiae (ΔbarX) and Streptomyces avermitilis (Δaco), respectively. In these strains, essential biosynthetic genes for Streptomyces hormones were disrupted, enabling them to respond solely to the externally added hormones. The results showed that 20% of each of the investigated strains produced IM-2 and VB, confirming that γ-butyrolactone-type Streptomyces hormones are the most common in actinomycetes. Unlike the γ-butyrolactone type, butenolide-type Streptomyces hormones have been discovered in recent years, but their distribution has been unclear. Our finding that 24% of actinomycetes (12 of 51 strains) showed avenolide activity revealed for the first time that the butenolide-type Streptomyces hormone is also common in actinomycetes.

  14. De Novo Assembly and Genome Analyses of the Marine-Derived Scopulariopsis brevicaulis Strain LF580 Unravels Life-Style Traits and Anticancerous Scopularide Biosynthetic Gene Cluster.

    Science.gov (United States)

    Kumar, Abhishek; Henrissat, Bernard; Arvas, Mikko; Syed, Muhammad Fahad; Thieme, Nils; Benz, J Philipp; Sørensen, Jens Laurids; Record, Eric; Pöggeler, Stefanie; Kempken, Frank

    2015-01-01

    The marine-derived Scopulariopsis brevicaulis strain LF580 produces scopularides A and B, which have anticancerous properties. We carried out genome sequencing using three next-generation DNA sequencing methods. De novo hybrid assembly yielded 621 scaffolds with a total size of 32.2 Mb and 16298 putative gene models. We identified a large non-ribosomal peptide synthetase gene (nrps1) and supporting pks2 gene in the same biosynthetic gene cluster. This cluster and the genes within the cluster are functionally active as confirmed by RNA-Seq. Characterization of carbohydrate-active enzymes and major facilitator superfamily (MFS)-type transporters lead to postulate S. brevicaulis originated from a soil fungus, which came into contact with the marine sponge Tethya aurantium. This marine sponge seems to provide shelter to this fungus and micro-environment suitable for its survival in the ocean. This study also builds the platform for further investigations of the role of life-style and secondary metabolites from S. brevicaulis.

  15. BGDMdocker: a Docker workflow for data mining and visualization of bacterial pan-genomes and biosynthetic gene clusters

    Directory of Open Access Journals (Sweden)

    Gong Cheng

    2017-11-01

    Full Text Available Recently, Docker technology has received increasing attention throughout the bioinformatics community. However, its implementation has not yet been mastered by most biologists; accordingly, its application in biological research has been limited. In order to popularize this technology in the field of bioinformatics and to promote the use of publicly available bioinformatics tools, such as Dockerfiles and Images from communities, government sources, and private owners in the Docker Hub Registry and other Docker-based resources, we introduce here a complete and accurate bioinformatics workflow based on Docker. The present workflow enables analysis and visualization of pan-genomes and biosynthetic gene clusters of bacteria. This provides a new solution for bioinformatics mining of big data from various publicly available biological databases. The present step-by-step guide creates an integrative workflow through a Dockerfile to allow researchers to build their own Image and run Container easily.

  16. BGDMdocker: a Docker workflow for data mining and visualization of bacterial pan-genomes and biosynthetic gene clusters.

    Science.gov (United States)

    Cheng, Gong; Lu, Quan; Ma, Ling; Zhang, Guocai; Xu, Liang; Zhou, Zongshan

    2017-01-01

    Recently, Docker technology has received increasing attention throughout the bioinformatics community. However, its implementation has not yet been mastered by most biologists; accordingly, its application in biological research has been limited. In order to popularize this technology in the field of bioinformatics and to promote the use of publicly available bioinformatics tools, such as Dockerfiles and Images from communities, government sources, and private owners in the Docker Hub Registry and other Docker-based resources, we introduce here a complete and accurate bioinformatics workflow based on Docker. The present workflow enables analysis and visualization of pan-genomes and biosynthetic gene clusters of bacteria. This provides a new solution for bioinformatics mining of big data from various publicly available biological databases. The present step-by-step guide creates an integrative workflow through a Dockerfile to allow researchers to build their own Image and run Container easily.

  17. Ultraviolet Radiation-Elicited Enhancement of Isoflavonoid Accumulation, Biosynthetic Gene Expression, and Antioxidant Activity in Astragalus membranaceus Hairy Root Cultures.

    Science.gov (United States)

    Jiao, Jiao; Gai, Qing-Yan; Wang, Wei; Luo, Meng; Gu, Cheng-Bo; Fu, Yu-Jie; Ma, Wei

    2015-09-23

    In this work, Astragalus membranaceus hairy root cultures (AMHRCs) were exposed to ultraviolet radiation (UV-A, UV-B, and UV-C) for promoting isoflavonoid accumulation. The optimum enhancement for isoflavonoid production was achieved in 34-day-old AMHRCs elicited by 86.4 kJ/m(2) of UV-B. The resulting isoflavonoid yield was 533.54 ± 13.61 μg/g dry weight (DW), which was 2.29-fold higher relative to control (232.93 ± 3.08 μg/g DW). UV-B up-regulated the transcriptional expressions of all investigated genes involved in isoflavonoid biosynthetic pathway. PAL and C4H were found to be two potential key genes that controlled isoflavonoid biosynthesis. Moreover, a significant increase was noted in antioxidant activity of extracts from UV-B-elicited AMHRCs (IC50 values = 0.85 and 1.08 mg/mL) in comparison with control (1.38 and 1.71 mg/mL). Overall, this study offered a feasible elicitation strategy to enhance isoflavonoid accumulation in AMHRCs and also provided a basis for metabolic engineering of isoflavonoid biosynthesis in the future.

  18. Identification and Functional Characterization of Genes Encoding Omega-3 Polyunsaturated Fatty Acid Biosynthetic Activities from Unicellular Microalgae

    Directory of Open Access Journals (Sweden)

    Royah Vaezi

    2013-12-01

    Full Text Available In order to identify novel genes encoding enzymes involved in the biosynthesis of nutritionally important omega-3 long chain polyunsaturated fatty acids, a database search was carried out in the genomes of the unicellular photoautotrophic green alga Ostreococcus RCC809 and cold-water diatom Fragilariopsis cylindrus. The search led to the identification of two putative “front-end” desaturases (Δ6 and Δ4 from Ostreococcus RCC809 and one Δ6-elongase from F. cylindrus. Heterologous expression of putative open reading frames (ORFs in yeast revealed that the encoded enzyme activities efficiently convert their respective substrates: 54.1% conversion of α-linolenic acid for Δ6-desaturase, 15.1% conversion of 22:5n-3 for Δ4-desaturase and 38.1% conversion of γ-linolenic acid for Δ6-elongase. The Δ6-desaturase from Ostreococcus RCC809 displays a very strong substrate preference resulting in the predominant synthesis of stearidonic acid (C18:4Δ6,9,12,15. These data confirm the functional characterization of omega-3 long chain polyunsaturated fatty acid biosynthetic genes from these two species which have until now not been investigated for such activities. The identification of these new genes will also serve to expand the repertoire of activities available for metabolically engineering the omega-3 trait in heterologous hosts as well as providing better insights into the synthesis of eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA in marine microalgae.

  19. Rice ethylene-response AP2/ERF factor OsEATB restricts internode elongation by down-regulating a gibberellin biosynthetic gene.

    Science.gov (United States)

    Qi, Weiwei; Sun, Fan; Wang, Qianjie; Chen, Mingluan; Huang, Yunqing; Feng, Yu-Qi; Luo, Xiaojin; Yang, Jinshui

    2011-09-01

    Plant height is a decisive factor in plant architecture. Rice (Oryza sativa) plants have the potential for rapid internodal elongation, which determines plant height. A large body of physiological research has shown that ethylene and gibberellin are involved in this process. The APETALA2 (AP2)/Ethylene-Responsive Element Binding Factor (ERF) family of transcriptional factors is only present in the plant kingdom. This family has various developmental and physiological functions. A rice AP2/ERF gene, OsEATB (for ERF protein associated with tillering and panicle branching) was cloned from indica rice variety 9311. Bioinformatic analysis suggested that this ERF has a potential new function. Ectopic expression of OsEATB showed that the cross talk between ethylene and gibberellin, which is mediated by OsEATB, might underlie differences in rice internode elongation. Analyses of gene expression demonstrated that OsEATB restricts ethylene-induced enhancement of gibberellin responsiveness during the internode elongation process by down-regulating the gibberellin biosynthetic gene, ent-kaurene synthase A. Plant height is negatively correlated with tiller number, and higher yields are typically obtained from dwarf crops. OsEATB reduces rice plant height and panicle length at maturity, promoting the branching potential of both tillers and spikelets. These are useful traits for breeding high-yielding crops.

  20. Elucidation of the biosynthetic pathway for the production of the pigment chrysogine by Penicillium chrysogenum

    NARCIS (Netherlands)

    Viggiano, Annarita; Salo, Oleksandr; Ali, Hazrat; Szymanski, Wiktor; Lankhorst, Peter P; Nygård, Yvonne; Bovenberg, Roel A L; Driessen, Arnold J M

    Chrysogine is a yellow pigment produced by Penicillium chrysogenum and other filamentous fungi. Although it was first isolated in 1973, the biosynthetic pathway has so far not been resolved. Here, we show that the deletion of the highly expressed non-ribosomal peptide synthetase (NRPS) gene

  1. Heterologous expression of oxytetracycline biosynthetic gene cluster in Streptomyces venezuelae WVR2006 to improve production level and to alter fermentation process.

    Science.gov (United States)

    Yin, Shouliang; Li, Zilong; Wang, Xuefeng; Wang, Huizhuan; Jia, Xiaole; Ai, Guomin; Bai, Zishang; Shi, Mingxin; Yuan, Fang; Liu, Tiejun; Wang, Weishan; Yang, Keqian

    2016-12-01

    Heterologous expression is an important strategy to activate biosynthetic gene clusters of secondary metabolites. Here, it is employed to activate and manipulate the oxytetracycline (OTC) gene cluster and to alter OTC fermentation process. To achieve these goals, a fast-growing heterologous host Streptomyces venezuelae WVR2006 was rationally selected among several potential hosts. It shows rapid and dispersed growth and intrinsic high resistance to OTC. By manipulating the expression of two cluster-situated regulators (CSR) OtcR and OtrR and precursor supply, the OTC production level was significantly increased in this heterologous host from 75 to 431 mg/l only in 48 h, a level comparable to the native producer Streptomyces rimosus M4018 in 8 days. This work shows that S. venezuelae WVR2006 is a promising chassis for the production of secondary metabolites, and the engineered heterologous OTC producer has the potential to completely alter the fermentation process of OTC production.

  2. In silico exploration of Red Sea Bacillus genomes for natural product biosynthetic gene clusters

    KAUST Repository

    Othoum, Ghofran K

    2018-05-22

    BackgroundThe increasing spectrum of multidrug-resistant bacteria is a major global public health concern, necessitating discovery of novel antimicrobial agents. Here, members of the genus Bacillus are investigated as a potentially attractive source of novel antibiotics due to their broad spectrum of antimicrobial activities. We specifically focus on a computational analysis of the distinctive biosynthetic potential of Bacillus paralicheniformis strains isolated from the Red Sea, an ecosystem exposed to adverse, highly saline and hot conditions.ResultsWe report the complete circular and annotated genomes of two Red Sea strains, B. paralicheniformis Bac48 isolated from mangrove mud and B. paralicheniformis Bac84 isolated from microbial mat collected from Rabigh Harbor Lagoon in Saudi Arabia. Comparing the genomes of B. paralicheniformis Bac48 and B. paralicheniformis Bac84 with nine publicly available complete genomes of B. licheniformis and three genomes of B. paralicheniformis, revealed that all of the B. paralicheniformis strains in this study are more enriched in nonribosomal peptides (NRPs). We further report the first computationally identified trans-acyltransferase (trans-AT) nonribosomal peptide synthetase/polyketide synthase (PKS/ NRPS) cluster in strains of this species.ConclusionsB. paralicheniformis species have more genes associated with biosynthesis of antimicrobial bioactive compounds than other previously characterized species of B. licheniformis, which suggests that these species are better potential sources for novel antibiotics. Moreover, the genome of the Red Sea strain B. paralicheniformis Bac48 is more enriched in modular PKS genes compared to B. licheniformis strains and other B. paralicheniformis strains. This may be linked to adaptations that strains surviving in the Red Sea underwent to survive in the relatively hot and saline ecosystems.

  3. Estimating P-coverage of biosynthetic pathways in DNA libraries and screening by genetic selection: biotin biosynthesis in the marine microorganism Chromohalobacter.

    Science.gov (United States)

    Kim, Eun Jin; Angell, Scott; Janes, Jeff; Watanabe, Coran M H

    2008-06-01

    Traditional approaches to natural product discovery involve cell-based screening of natural product extracts followed by compound isolation and characterization. Their importance notwithstanding, continued mining leads to depletion of natural resources and the reisolation of previously identified metabolites. Metagenomic strategies aimed at localizing the biosynthetic cluster genes and expressing them in surrogate hosts offers one possible alternative. A fundamental question that naturally arises when pursuing such a strategy is, how large must the genomic library be to effectively represent the genome of an organism(s) and the biosynthetic gene clusters they harbor? Such an issue is certainly augmented in the absence of expensive robotics to expedite colony picking and/or screening of clones. We have developed an algorism, named BPC (biosynthetic pathway coverage), supported by molecular simulations to deduce the number of BAC clones required to achieve proper coverage of the genome and their respective biosynthetic pathways. The strategy has been applied to the construction of a large-insert BAC library from a marine microorganism, Hon6 (isolated from Honokohau, Maui) thought to represent a new species. The genomic library is constructed with a BAC yeast shuttle vector pClasper lacZ paving the way for the culturing of libraries in both prokaryotic and eukaryotic hosts. Flow cytometric methods are utilized to estimate the genome size of the organism and BPC implemented to assess P-coverage or percent coverage. A genetic selection strategy is illustrated, applications of which could expedite screening efforts in the identification and localization of biosynthetic pathways from marine microbial consortia, offering a powerful complement to genome sequencing and degenerate probe strategies. Implementing this approach, we report on the biotin biosynthetic pathway from the marine microorganism Hon6.

  4. Biosynthetic multitasking facilitates thalassospiramide structural diversity in marine bacteria

    KAUST Repository

    Ross, Avena C.

    2013-01-23

    Thalassospiramides A and B are immunosuppressant cyclic lipopeptides first reported from the marine α-proteobacterium Thalassospira sp. CNJ-328. We describe here the discovery and characterization of an extended family of 14 new analogues from four Tistrella and Thalassospira isolates. These potent calpain 1 protease inhibitors belong to six structure classes in which the length and composition of the acylpeptide side chain varies extensively. Genomic sequence analysis of the thalassospiramide-producing microbes revealed related, genus-specific biosynthetic loci encoding hybrid nonribosomal peptide synthetase/polyketide synthases consistent with thalassospiramide assembly. The bioinformatics analysis of the gene clusters suggests that structural diversity, which ranges from the 803.4 Da thalassospiramide C to the 1291.7 Da thalassospiramide F, results from a complex sequence of reactions involving amino acid substrate channeling and enzymatic multimodule skipping and iteration. Preliminary biochemical analysis of the N-terminal nonribosomal peptide synthetase module from the Thalassospira TtcA megasynthase supports a biosynthetic model in which in cis amino acid activation competes with in trans activation to increase the range of amino acid substrates incorporated at the N terminus. © 2012 American Chemical Society.

  5. Biosynthetic multitasking facilitates thalassospiramide structural diversity in marine bacteria

    KAUST Repository

    Ross, Avena C.; Xü , Ying; Lu, Liang; Kersten, Roland D.; Shao, Zongze; Al-Suwailem, Abdulaziz M.; Dorrestein, Pieter C.; Qian, Peiyuan; Moore, Bradley S.

    2013-01-01

    Thalassospiramides A and B are immunosuppressant cyclic lipopeptides first reported from the marine α-proteobacterium Thalassospira sp. CNJ-328. We describe here the discovery and characterization of an extended family of 14 new analogues from four Tistrella and Thalassospira isolates. These potent calpain 1 protease inhibitors belong to six structure classes in which the length and composition of the acylpeptide side chain varies extensively. Genomic sequence analysis of the thalassospiramide-producing microbes revealed related, genus-specific biosynthetic loci encoding hybrid nonribosomal peptide synthetase/polyketide synthases consistent with thalassospiramide assembly. The bioinformatics analysis of the gene clusters suggests that structural diversity, which ranges from the 803.4 Da thalassospiramide C to the 1291.7 Da thalassospiramide F, results from a complex sequence of reactions involving amino acid substrate channeling and enzymatic multimodule skipping and iteration. Preliminary biochemical analysis of the N-terminal nonribosomal peptide synthetase module from the Thalassospira TtcA megasynthase supports a biosynthetic model in which in cis amino acid activation competes with in trans activation to increase the range of amino acid substrates incorporated at the N terminus. © 2012 American Chemical Society.

  6. Overexpression of the riboflavin biosynthetic pathway in Pichia pastoris

    Directory of Open Access Journals (Sweden)

    Mattanovich Diethard

    2008-07-01

    Full Text Available Abstract Background High cell density cultures of Pichia pastoris grown on methanol tend to develop yellow colored supernatants, attributed to the release of free flavins. The potential of P. pastoris for flavin overproduction is therefore given, but not pronounced when the yeast is grown on glucose. The aim of this study is to characterize the relative regulatory impact of each riboflavin synthesis gene. Deeper insight into pathway control and the potential of deregulation is established by overexpression of the single genes as well as a combined deregulation of up to all six riboflavin synthesis genes. Results Overexpression of the first gene of the riboflavin biosynthetic pathway (RIB1 is already sufficient to obtain yellow colonies and the accumulation of riboflavin in the supernatant of shake flask cultures growing on glucose. Sequential deregulation of all the genes, by exchange of their native promoter with the strong and constitutive glyceraldehyde-3-phosphate dehydrogenase promoter (PGAP increases the riboflavin accumulation significantly. Conclusion The regulation of the pathway is distributed over more than one gene. High cell density cultivations of a P. pastoris strain overexpressing all six RIB genes allow the accumulation of 175 mg/L riboflavin in the supernatant. The basis for rational engineering of riboflavin production in P. pastoris has thus been established.

  7. An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae (on linr)

    NARCIS (Netherlands)

    Wang, Kui-Lin; Bolitho, Karen; Grafton, Karryn; Kortstee, A.J.; Karunairetnam, Sakuntala; McGhie, T.K.; Espley, R.V.; Hellens, R.P.; Allan, A.C.

    2010-01-01

    Background - The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the

  8. Diverse and Abundant Secondary Metabolism Biosynthetic Gene Clusters in the Genomes of Marine Sponge Derived Streptomyces spp. Isolates

    Directory of Open Access Journals (Sweden)

    Stephen A. Jackson

    2018-02-01

    Full Text Available The genus Streptomyces produces secondary metabolic compounds that are rich in biological activity. Many of these compounds are genetically encoded by large secondary metabolism biosynthetic gene clusters (smBGCs such as polyketide synthases (PKS and non-ribosomal peptide synthetases (NRPS which are modular and can be highly repetitive. Due to the repeats, these gene clusters can be difficult to resolve using short read next generation datasets and are often quite poorly predicted using standard approaches. We have sequenced the genomes of 13 Streptomyces spp. strains isolated from shallow water and deep-sea sponges that display antimicrobial activities against a number of clinically relevant bacterial and yeast species. Draft genomes have been assembled and smBGCs have been identified using the antiSMASH (antibiotics and Secondary Metabolite Analysis Shell web platform. We have compared the smBGCs amongst strains in the search for novel sequences conferring the potential to produce novel bioactive secondary metabolites. The strains in this study recruit to four distinct clades within the genus Streptomyces. The marine strains host abundant smBGCs which encode polyketides, NRPS, siderophores, bacteriocins and lantipeptides. The deep-sea strains appear to be enriched with gene clusters encoding NRPS. Marine adaptations are evident in the sponge-derived strains which are enriched for genes involved in the biosynthesis and transport of compatible solutes and for heat-shock proteins. Streptomyces spp. from marine environments are a promising source of novel bioactive secondary metabolites as the abundance and diversity of smBGCs show high degrees of novelty. Sponge derived Streptomyces spp. isolates appear to display genomic adaptations to marine living when compared to terrestrial strains.

  9. ClbM is a versatile, cation-promiscuous MATE transporter found in the colibactin biosynthetic gene cluster.

    Science.gov (United States)

    Mousa, Jarrod J; Newsome, Rachel C; Yang, Ye; Jobin, Christian; Bruner, Steven D

    2017-01-22

    Multidrug transporters play key roles in cellular drug resistance to toxic molecules, yet these transporters are also involved in natural product transport as part of biosynthetic clusters in bacteria and fungi. The genotoxic molecule colibactin is produced by strains of virulent and pathobiont Escherichia coli and Klebsiella pneumoniae. In the biosynthetic cluster is a multidrug and toxic compound extrusion protein (MATE) proposed to transport the prodrug molecule precolibactin across the cytoplasmic membrane, for subsequent cleavage by the peptidase ClbP and cellular export. We recently determined the X-ray structure of ClbM, and showed preliminary data suggesting its specific role in precolibactin transport. Here, we define a functional role of ClbM by examining transport capabilities under various biochemical conditions. Our data indicate ClbM responds to sodium, potassium, and rubidium ion gradients, while also having substantial transport activity in the absence of alkali cations. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Biosynthetic origin of acetic acid using SNIF-NMR

    International Nuclear Information System (INIS)

    Boffo, Elisangela Fabiana; Ferreira, Antonio Gilberto

    2006-01-01

    The main purpose of this work is to describe the use of the technique Site-Specific Natural Isotopic Fractionation of hydrogen (SNIF-NMR), using 2 H and 1 H NMR spectroscopy, to investigate the biosynthetic origin of acetic acid in commercial samples of Brazilian vinegar. This method is based on the deuterium to hydrogen ratio at a specific position (methyl group) of acetic acid obtained by fermentation, through different biosynthetic mechanisms, which result in different isotopic ratios. We measured the isotopic ratio of vinegars obtained through C 3 , C 4 , and CAM biosynthetic mechanisms, blends of C 3 and C 4 (agrins) and synthetic acetic acid. (author)

  11. Differential expression of anthocyanin biosynthetic genes in relation to anthocyanin accumulation in the pericarp of Litchi chinensis Sonn.

    Directory of Open Access Journals (Sweden)

    Yong-Zan Wei

    Full Text Available Litchi has diverse fruit color phenotypes, yet no research reflects the biochemical background of this diversity. In this study, we evaluated 12 litchi cultivars for chromatic parameters and pigments, and investigated the effects of abscisic acid, forchlorofenron (CPPU, bagging and debagging treatments on fruit coloration in cv. Feizixiao, an unevenly red cultivar. Six genes encoding chalcone synthase (CHS, chalcone isomerase (CHI, flavanone 3-hydroxylase (F3H, dihydroflavonol 4-reductase (DFR, anthocyanidin synthase (ANS and UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT were isolated from the pericarp of the fully red litchi cv. Nuomici, and their expression was analyzed in different cultivars and under the above mentioned treatments. Pericarp anthocyanin concentration varied from none to 734 mg m(-2 among the 12 litchi cultivars, which were divided into three coloration types, i.e. non-red ('Kuixingqingpitian', 'Xingqiumili', 'Yamulong'and 'Yongxing No. 2', unevenly red ('Feizixiao' and 'Sanyuehong' and fully red ('Meiguili', 'Baila', Baitangying' 'Guiwei', 'Nuomici' and 'Guinuo'. The fully red type cultivars had different levels of anthocyanin but with the same composition. The expression of the six genes, especially LcF3H, LcDFR, LcANS and LcUFGT, in the pericarp of non-red cultivars was much weaker as compared to those red cultivars. Their expression, LcDFR and LcUFGT in particular, was positively correlated with anthocyanin concentrations in the pericarp. These results suggest the late genes in the anthocyanin biosynthetic pathway were coordinately expressed during red coloration of litchi fruits. Low expression of these genes resulted in absence or extremely low anthocyanin accumulation in non-red cultivars. Zero-red pericarp from either immature or CPPU treated fruits appeared to be lacking in anthocyanins due to the absence of UFGT expression. Among these six genes, only the expression of UFGT was found significantly correlated

  12. An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae (on linr)

    OpenAIRE

    Wang, Kui-Lin; Bolitho, Karen; Grafton, Karryn; Kortstee, A.J.; Karunairetnam, Sakuntala; McGhie, T.K.; Espley, R.V.; Hellens, R.P.; Allan, A.C.

    2010-01-01

    Background - The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the gene determining fruit flesh and foliage anthocyanin has been termed MYB10. In order to further understand tissue-specific anthocyanin regulation we have isolated orthologous MYB genes from all th...

  13. Molecular evolution of the lysine biosynthetic pathways.

    Science.gov (United States)

    Velasco, A M; Leguina, J I; Lazcano, A

    2002-10-01

    Among the different biosynthetic pathways found in extant organisms, lysine biosynthesis is peculiar because it has two different anabolic routes. One is the diaminopimelic acid pathway (DAP), and the other over the a-aminoadipic acid route (AAA). A variant of the AAA route that includes some enzymes involved in arginine and leucine biosyntheses has been recently reported in Thermus thermophilus (Nishida et al. 1999). Here we describe the results of a detailed genomic analysis of each of the sequences involved in the two lysine anabolic routes, as well as of genes from other routes related to them. No evidence was found of an evolutionary relationship between the DAP and AAA enzymes. Our results suggest that the DAP pathway is related to arginine metabolism, since the lysC, asd, dapC, dapE, and lysA genes from lysine biosynthesis are related to the argB, argC, argD, argE, and speAC genes, respectively, whose products catalyze different steps in arginine metabolism. This work supports previous reports on the relationship between AAA gene products and some enzymes involved in leucine biosynthesis and the tricarboxylic acid cycle (Irvin and Bhattacharjee 1998; Miyazaki et al. 2001). Here we discuss the significance of the recent finding that several genes involved in the arginine (Arg) and leucine (Leu) biosynthesis participate in a new alternative route of the AAA pathway (Miyazaki et al. 2001). Our results demonstrate a clear relationship between the DAP and Arg routes, and between the AAA and Leu pathways.

  14. Rice Ethylene-Response AP2/ERF Factor OsEATB Restricts Internode Elongation by Down-Regulating a Gibberellin Biosynthetic Gene1[W][OA

    Science.gov (United States)

    Qi, Weiwei; Sun, Fan; Wang, Qianjie; Chen, Mingluan; Huang, Yunqing; Feng, Yu-Qi; Luo, Xiaojin; Yang, Jinshui

    2011-01-01

    Plant height is a decisive factor in plant architecture. Rice (Oryza sativa) plants have the potential for rapid internodal elongation, which determines plant height. A large body of physiological research has shown that ethylene and gibberellin are involved in this process. The APETALA2 (AP2)/Ethylene-Responsive Element Binding Factor (ERF) family of transcriptional factors is only present in the plant kingdom. This family has various developmental and physiological functions. A rice AP2/ERF gene, OsEATB (for ERF protein associated with tillering and panicle branching) was cloned from indica rice variety 9311. Bioinformatic analysis suggested that this ERF has a potential new function. Ectopic expression of OsEATB showed that the cross talk between ethylene and gibberellin, which is mediated by OsEATB, might underlie differences in rice internode elongation. Analyses of gene expression demonstrated that OsEATB restricts ethylene-induced enhancement of gibberellin responsiveness during the internode elongation process by down-regulating the gibberellin biosynthetic gene, ent-kaurene synthase A. Plant height is negatively correlated with tiller number, and higher yields are typically obtained from dwarf crops. OsEATB reduces rice plant height and panicle length at maturity, promoting the branching potential of both tillers and spikelets. These are useful traits for breeding high-yielding crops. PMID:21753115

  15. Transcriptional repressor role of PocR on the 1,3-propanediol biosynthetic pathway by Lactobacillus panis PM1.

    Science.gov (United States)

    Kang, Tae Sun; Korber, Darren R; Tanaka, Takuji

    2014-06-01

    The regulatory role of a transcriptional regulator (PocR) in the 1,3-propanediol biosynthetic pathway of Lactobacillus panis PM1 contributes to the optimization of 1,3-propanediol production by this strain, which potentially will lead to 1,3-propanediol manufacturing efficiencies. Lactobacillus panis PM1 can utilize a 1,3-propanediol (1,3-PDO) biosynthetic pathway, consisting of diol dehydratase (PduCDE) and 1,3-PDO dehydrogenase, as a NADH recycling system, to survive under various environmental conditions. In this study, we identified a key transcriptional repressor (PocR) which was annotated as a transcriptional factor of AraC family as part of the 1,3-PDO biosynthetic pathway of L. panis PM1. The over-expression of the PocR gene resulted in the significant repression (81 %) of pduC (PduCDE large subunit) transcription, and subsequently, the decreased activity of PduCDE by 22 %. As a result of the regulation of PduCDE, production of both 3-hydroxypropionaldehyde and 1,3-PDO in the PocR over-expressing strain were significantly decreased by 40 % relative to the control strain. These results clearly demonstrate the transcriptional repressor role of PocR in the 1,3-PDO biosynthetic pathway.

  16. Effect of immobilization stress on gene expression of catecholamine biosynthetic enzymes in heart auricles of socially isolated rats

    Directory of Open Access Journals (Sweden)

    L. Gavrilovic

    2009-12-01

    Full Text Available Chronic stress is associated with the development of cardiovascular diseases. The sympathoneural system plays an important role in the regulation of cardiac function both in health and disease. In the present study, the changes in gene expression of the catecholamine biosynthetic enzymes tyrosine hydroxylase (TH, dopamine-β-hydroxylase (DBH and phenylethanolamine N-methyltransferase (PNMT and protein levels in the right and left heart auricles of naive control and long-term (12 weeks socially isolated rats were investigated by Taqman RT-PCR and Western blot analysis. The response of these animals to additional immobilization stress (2 h was also examined. Long-term social isolation produced a decrease in TH mRNA level in left auricles (about 70% compared to the corresponding control. Expression of the DBH gene was markedly decreased both in the right (about 62% and left (about 81% auricles compared to the corresponding control, group-maintained rats, whereas PNMT mRNA levels remained unchanged. Exposure of group-housed rats to acute immobilization for 2 h led to a significant increase of mRNA levels of TH (about 267%, DBH (about 37% and PNMT (about 60% only in the right auricles. Additional 2-h immobilization of individually housed rats did not affect gene expression of these enzymes in either the right or left auricle. Protein levels of TH, DBH and PNMT in left and right heart auricles were unchanged either in both individually housed and immobilized rats. The unchanged mRNA levels of the enzymes examined after short-term immobilization suggest that the catecholaminergic system of the heart auricles of animals previously exposed to chronic psychosocial stress was adapted to maintain appropriate cardiovascular homeostasis.

  17. Biosynthetic pathway for γ-cyclic sarcinaxanthin in Micrococcus luteus: heterologous expression and evidence for diverse and multiple catalytic functions of C(50) carotenoid cyclases.

    Science.gov (United States)

    Netzer, Roman; Stafsnes, Marit H; Andreassen, Trygve; Goksøyr, Audun; Bruheim, Per; Brautaset, Trygve

    2010-11-01

    We report the cloning and characterization of the biosynthetic gene cluster (crtE, crtB, crtI, crtE2, crtYg, crtYh, and crtX) of the γ-cyclic C(50) carotenoid sarcinaxanthin in Micrococcus luteus NCTC2665. Expression of the complete and partial gene cluster in Escherichia coli hosts revealed that sarcinaxanthin biosynthesis from the precursor molecule farnesyl pyrophosphate (FPP) proceeds via C(40) lycopene, C(45) nonaflavuxanthin, C(50) flavuxanthin, and C(50) sarcinaxanthin. Glucosylation of sarcinaxanthin was accomplished by the crtX gene product. This is the first report describing the biosynthetic pathway of a γ-cyclic C(50) carotenoid. Expression of the corresponding genes from the marine M. luteus isolate Otnes7 in a lycopene-producing E. coli host resulted in the production of up to 2.5 mg/g cell dry weight sarcinaxanthin in shake flasks. In an attempt to experimentally understand the specific difference between the biosynthetic pathways of sarcinaxanthin and the structurally related ε-cyclic decaprenoxanthin, we constructed a hybrid gene cluster with the γ-cyclic C(50) carotenoid cyclase genes crtYg and crtYh from M. luteus replaced with the analogous ε-cyclic C(50) carotenoid cyclase genes crtYe and crtYf from the natural decaprenoxanthin producer Corynebacterium glutamicum. Surprisingly, expression of this hybrid gene cluster in an E. coli host resulted in accumulation of not only decaprenoxanthin, but also sarcinaxanthin and the asymmetric ε- and γ-cyclic C(50) carotenoid sarprenoxanthin, described for the first time in this work. Together, these data contributed to new insight into the diverse and multiple functions of bacterial C(50) carotenoid cyclases as key catalysts for the synthesis of structurally different carotenoids.

  18. Perturbations of carotenoid and tetrapyrrole biosynthetic pathways result in differential alterations in chloroplast function and plastid signaling.

    Science.gov (United States)

    Park, Joon-Heum; Jung, Sunyo

    2017-01-22

    In this study, we used the biosynthetic inhibitors of carotenoid and tetrapyrrole biosynthetic pathways, norflurazon (NF) and oxyfluorfen (OF), as tools to gain insight into mechanisms of photooxidation in rice plants. NF resulted in bleaching symptom on leaves of the treated plants, whereas OF treatment developed a fast symptom of an apparent necrotic phenotype. Both plants exhibited decreases in photosynthetic efficiency, as indicated by F v /F m . NF caused severe disruption in thylakoid membranes, whereas OF-treated plants exhibited disruption of chloroplast envelope and plasma membrane. Levels of Lhca and Lhcb proteins in photosystem I (PSI) and PSII were reduced by photooxidative stress in NF- and OF-treated plants, with a greater decrease in NF plants. The down-regulation of nuclear-encoded photosynthesis genes Lhcb and rbcS was also found in both NF- and OF-treated plants, whereas plastid-encoded photosynthetic genes including RbcL, PsaC, and PsbD accumulated normally in NF plants but decreased drastically in OF plants. This proposes that the plastids in NF plants retain their potential to develop thylakoid membranes and that photobleaching is mainly controlled by nuclear genes. Distinct photooxidation patterns between NF- and OF-treated plants developed differential signaling, which might enable the plant to coordinate the expression of photosynthetic genes from the nuclear and plastidic genomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Functional Characterization of a Novel R2R3-MYB Transcription Factor Modulating the Flavonoid Biosynthetic Pathway from Epimedium sagittatum

    Directory of Open Access Journals (Sweden)

    Wenjun Huang

    2017-07-01

    Full Text Available Epimedium species have been widely used both as traditional Chinese medicinal plants and ornamental perennials. Both flavonols, acting as the major bioactive components (BCs and anthocyanins, predominantly contributing to the color diversity of Epimedium flowers belong to different classes of flavonoids. It is well-acknowledged that flavonoid biosynthetic pathway is predominantly regulated by R2R3-MYB transcription factor (TF as well as bHLH TF and WD40 protein at the transcriptional level. MYB TFs specifically regulating anthocyanin or flavonol biosynthetic pathway have been already isolated and functionally characterized from Epimedium sagittatum, but a R2R3-MYB TF involved in regulating both these two pathways has not been functionally characterized to date in Epimedium plants. In this study, we report the functional characterization of EsMYB9, a R2R3-MYB TF previously isolated from E. sagittatum. The previous study indicated that EsMYB9 belongs to a small subfamily of R2R3-MYB TFs containing grape VvMYB5a and VvMYB5b TFs, which regulate flavonoid biosynthetic pathway. The present studies show that overexpression of EsMYB9 in tobacco leads to increased transcript levels of flavonoid pathway genes and increased contents of anthocyanins and flavonols. Yeast two-hybrid assay indicates that the C-terminal region of EsMYB9 contributes to the autoactivation activity, and EsMYB9 interacts with EsTT8 or AtTT8 bHLH regulator. Transient reporter assay shows that EsMYB9 slightly activates the expression of EsCHS (chalcone synthase promoter in transiently transformed leaves of Nicotiana benthamiana, but the addition of AtTT8 or EsTT8 bHLH regulator strongly enhances the transcriptional activation of EsMYB9 against five promoters of the flavonoid pathway genes except EsFLS (flavonol synthase. In addition, co-transformation of EsMYB9 and EsTT8 in transiently transfected tobacco leaves strongly induces the expressions of flavonoid biosynthetic genes. The

  20. ClbM is a versatile, cation-promiscuous MATE transporter found in the colibactin biosynthetic gene cluster

    International Nuclear Information System (INIS)

    Mousa, Jarrod J.; Newsome, Rachel C.; Yang, Ye; Jobin, Christian; Bruner, Steven D.

    2017-01-01

    Multidrug transporters play key roles in cellular drug resistance to toxic molecules, yet these transporters are also involved in natural product transport as part of biosynthetic clusters in bacteria and fungi. The genotoxic molecule colibactin is produced by strains of virulent and pathobiont Escherichia coli and Klebsiella pneumoniae. In the biosynthetic cluster is a multidrug and toxic compound extrusion protein (MATE) proposed to transport the prodrug molecule precolibactin across the cytoplasmic membrane, for subsequent cleavage by the peptidase ClbP and cellular export. We recently determined the X-ray structure of ClbM, and showed preliminary data suggesting its specific role in precolibactin transport. Here, we define a functional role of ClbM by examining transport capabilities under various biochemical conditions. Our data indicate ClbM responds to sodium, potassium, and rubidium ion gradients, while also having substantial transport activity in the absence of alkali cations. - Highlights: • ClbM is a cation promiscuous MATE multidrug transporter. • The role of key residues were identified in both the cation and proton binding. • The biologically relevant substrate for ClbM is the natural product precolibactin.

  1. Transcriptional regulation of genes involved in terpenoid índole alkaloid production in Catharanthus roseus seedlings

    Directory of Open Access Journals (Sweden)

    Pedro J. Rocha

    2002-07-01

    Full Text Available Catharanthus roseus (L. G Don is a medicinal plant that produces a variety of terpenoid indole alkaloids (TIAs, some of which display pharmacological activity. C. roseus plants and cell cultures have been used to elucidate the TIAs biosynthetic pathway. A considerable number or enzymes have also been characterised, and their respective genes cloned. TIAs production in C. roseus plant and cell cultures is highly regulated at transcriptional-, develop-mental-, and environmental-level. Studies into TIAs biosynthetic gene regulation have been carried out using cell cultures. However, regulation in plants is almost unknown. Here, biosynthetic genes idc, strl, d4h and dat expres-sion levels are qualitatively examined in a developmental series of C. roseus seedlings. The effect of water- and light-stress and methyl jasmonate (MeJa and acetyl salicylic acid (ASA elicitation is also examined. Comparison between seedlings and cell cultures strongly suggests that TIAs biosynthetic gene transcriptional regulation is different in C.roseus plants and cell cultures.

  2. Analysis of the transcriptome of Panax notoginseng root uncovers putative triterpene saponin-biosynthetic genes and genetic markers

    Science.gov (United States)

    2011-01-01

    Background Panax notoginseng (Burk) F.H. Chen is important medicinal plant of the Araliacease family. Triterpene saponins are the bioactive constituents in P. notoginseng. However, available genomic information regarding this plant is limited. Moreover, details of triterpene saponin biosynthesis in the Panax species are largely unknown. Results Using the 454 pyrosequencing technology, a one-quarter GS FLX titanium run resulted in 188,185 reads with an average length of 410 bases for P. notoginseng root. These reads were processed and assembled by 454 GS De Novo Assembler software into 30,852 unique sequences. A total of 70.2% of unique sequences were annotated by Basic Local Alignment Search Tool (BLAST) similarity searches against public sequence databases. The Kyoto Encyclopedia of Genes and Genomes (KEGG) assignment discovered 41 unique sequences representing 11 genes involved in triterpene saponin backbone biosynthesis in the 454-EST dataset. In particular, the transcript encoding dammarenediol synthase (DS), which is the first committed enzyme in the biosynthetic pathway of major triterpene saponins, is highly expressed in the root of four-year-old P. notoginseng. It is worth emphasizing that the candidate cytochrome P450 (Pn02132 and Pn00158) and UDP-glycosyltransferase (Pn00082) gene most likely to be involved in hydroxylation or glycosylation of aglycones for triterpene saponin biosynthesis were discovered from 174 cytochrome P450s and 242 glycosyltransferases by phylogenetic analysis, respectively. Putative transcription factors were detected in 906 unique sequences, including Myb, homeobox, WRKY, basic helix-loop-helix (bHLH), and other family proteins. Additionally, a total of 2,772 simple sequence repeat (SSR) were identified from 2,361 unique sequences, of which, di-nucleotide motifs were the most abundant motif. Conclusion This study is the first to present a large-scale EST dataset for P. notoginseng root acquired by next-generation sequencing (NGS

  3. Analysis of the transcriptome of Panax notoginseng root uncovers putative triterpene saponin-biosynthetic genes and genetic markers

    Directory of Open Access Journals (Sweden)

    Luo Hongmei

    2011-12-01

    Full Text Available Abstract Background Panax notoginseng (Burk F.H. Chen is important medicinal plant of the Araliacease family. Triterpene saponins are the bioactive constituents in P. notoginseng. However, available genomic information regarding this plant is limited. Moreover, details of triterpene saponin biosynthesis in the Panax species are largely unknown. Results Using the 454 pyrosequencing technology, a one-quarter GS FLX titanium run resulted in 188,185 reads with an average length of 410 bases for P. notoginseng root. These reads were processed and assembled by 454 GS De Novo Assembler software into 30,852 unique sequences. A total of 70.2% of unique sequences were annotated by Basic Local Alignment Search Tool (BLAST similarity searches against public sequence databases. The Kyoto Encyclopedia of Genes and Genomes (KEGG assignment discovered 41 unique sequences representing 11 genes involved in triterpene saponin backbone biosynthesis in the 454-EST dataset. In particular, the transcript encoding dammarenediol synthase (DS, which is the first committed enzyme in the biosynthetic pathway of major triterpene saponins, is highly expressed in the root of four-year-old P. notoginseng. It is worth emphasizing that the candidate cytochrome P450 (Pn02132 and Pn00158 and UDP-glycosyltransferase (Pn00082 gene most likely to be involved in hydroxylation or glycosylation of aglycones for triterpene saponin biosynthesis were discovered from 174 cytochrome P450s and 242 glycosyltransferases by phylogenetic analysis, respectively. Putative transcription factors were detected in 906 unique sequences, including Myb, homeobox, WRKY, basic helix-loop-helix (bHLH, and other family proteins. Additionally, a total of 2,772 simple sequence repeat (SSR were identified from 2,361 unique sequences, of which, di-nucleotide motifs were the most abundant motif. Conclusion This study is the first to present a large-scale EST dataset for P. notoginseng root acquired by next

  4. The expression of antibiotic resistance genes in antibiotic-producing bacteria.

    Science.gov (United States)

    Mak, Stefanie; Xu, Ye; Nodwell, Justin R

    2014-08-01

    Antibiotic-producing bacteria encode antibiotic resistance genes that protect them from the biologically active molecules that they produce. The expression of these genes needs to occur in a timely manner: either in advance of or concomitantly with biosynthesis. It appears that there have been at least two general solutions to this problem. In many cases, the expression of resistance genes is tightly linked to that of antibiotic biosynthetic genes. In others, the resistance genes can be induced by their cognate antibiotics or by intermediate molecules from their biosynthetic pathways. The regulatory mechanisms that couple resistance to antibiotic biosynthesis are mechanistically diverse and potentially relevant to the origins of clinical antibiotic resistance. © 2014 John Wiley & Sons Ltd.

  5. Overexpression of the Squalene Epoxidase Gene Alone and in Combination with the 3-Hydroxy-3-methylglutaryl Coenzyme A Gene Increases Ganoderic Acid Production in Ganoderma lingzhi.

    Science.gov (United States)

    Zhang, De-Huai; Jiang, Lu-Xi; Li, Na; Yu, Xuya; Zhao, Peng; Li, Tao; Xu, Jun-Wei

    2017-06-14

    The squalene epoxidase (SE) gene from the biosynthetic pathway of ganoderic acid (GA) was cloned and overexpressed in Ganoderma lingzhi. The strain that overexpressed the SE produced approximately 2 times more GA molecules than the wild-type (WT) strain. Moreover, SE overexpression upregulated lanosterol synthase gene expression in the biosynthetic pathway. These results indicated that SE stimulates GA accumulation. Then, the SE and 3-hydroxy-3-methylglutaryl coenzyme A (HMGR) genes were simultaneously overexpressed in G. lingzhi. Compared with the individual overexpression of SE or HMGR, the combined overexpression of the two genes further enhanced individual GA production. The overexpressing strain produced maximum GA-T, GA-S, GA-Mk, and GA-Me contents of 90.4 ± 7.5, 35.9 ± 5.4, 6.2 ± 0.5, and 61.8 ± 5.8 μg/100 mg dry weight, respectively. These values were 5.9, 4.5, 2.4, and 5.8 times higher than those produced by the WT strain. This is the first example of the successful manipulation of multiple biosynthetic genes to improve GA content in G. lingzhi.

  6. The preliminary research for biosynthetic engineering by radiation fusion technology

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Chang Hyun; Jung, U Hee; Park, Hae Ran [KAERI, Daejeon (Korea, Republic of)

    2012-01-15

    The purpose of this project is to elucidate the solution to the production of bioactive substance using biotransformation process from core technology of biosynthetic engineering by radiation fusion technology. And, this strategy will provide core technology for development of drugs as new concept and category. Research scopes and contents of project include 1) The development of mutant for biosynthetic engineering by radiation fusion technology 2) The development of host for biosynthetic engineering by radiation fusion technology 3) The preliminary study for biosynthetic engineering of isoflavone by radiation fusion technology. The results are as follows. Isoflavone compounds(daidzein, hydroxylated isoflavone) were analyzed by GC-MS. The study of radiation doses and p-NCA high-throughput screening for mutant development were elucidated. And, it was carried out the study of radiation doses for host development. Furthermore, the study of redox partner and construction of recombinant strain for region-specific hydroxylation(P450, redox partner). In addition, the biological effect of 6,7,4'-trihydroxyisoflavone as an anti-obesity agent was elucidated in this study.

  7. Deciphering the sugar biosynthetic pathway and tailoring steps of nucleoside antibiotic A201A unveils a GDP-l-galactose mutase.

    Science.gov (United States)

    Zhu, Qinghua; Chen, Qi; Song, Yongxiang; Huang, Hongbo; Li, Jun; Ma, Junying; Li, Qinglian; Ju, Jianhua

    2017-05-09

    Galactose, a monosaccharide capable of assuming two possible configurational isomers (d-/l-), can exist as a six-membered ring, galactopyranose (Gal p ), or as a five-membered ring, galactofuranose (Gal f ). UDP-galactopyranose mutase (UGM) mediates the conversion of pyranose to furanose thereby providing a precursor for d-Gal f Moreover, UGM is critical to the virulence of numerous eukaryotic and prokaryotic human pathogens and thus represents an excellent antimicrobial drug target. However, the biosynthetic mechanism and relevant enzymes that drive l-Gal f production have not yet been characterized. Herein we report that efforts to decipher the sugar biosynthetic pathway and tailoring steps en route to nucleoside antibiotic A201A led to the discovery of a GDP-l-galactose mutase, MtdL. Systematic inactivation of 18 of the 33 biosynthetic genes in the A201A cluster and elucidation of 10 congeners, coupled with feeding and in vitro biochemical experiments, enabled us to: ( i ) decipher the unique enzyme, GDP-l-galactose mutase associated with production of two unique d-mannose-derived sugars, and ( ii ) assign two glycosyltransferases, four methyltransferases, and one desaturase that regiospecifically tailor the A201A scaffold and display relaxed substrate specificities. Taken together, these data provide important insight into the origin of l-Gal f -containing natural product biosynthetic pathways with likely ramifications in other organisms and possible antimicrobial drug targeting strategies.

  8. Mutation of a Rice Gene Encoding a Phenylalanine Biosynthetic Enzyme Results in Accumulation of Phenylalanine and Tryptophan[W

    Science.gov (United States)

    Yamada, Tetsuya; Matsuda, Fumio; Kasai, Koji; Fukuoka, Shuichi; Kitamura, Keisuke; Tozawa, Yuzuru; Miyagawa, Hisashi; Wakasa, Kyo

    2008-01-01

    Two distinct biosynthetic pathways for Phe in plants have been proposed: conversion of prephenate to Phe via phenylpyruvate or arogenate. The reactions catalyzed by prephenate dehydratase (PDT) and arogenate dehydratase (ADT) contribute to these respective pathways. The Mtr1 mutant of rice (Oryza sativa) manifests accumulation of Phe, Trp, and several phenylpropanoids, suggesting a link between the synthesis of Phe and Trp. Here, we show that the Mtr1 mutant gene (mtr1-D) encodes a form of rice PDT with a point mutation in the putative allosteric regulatory region of the protein. Transformed callus lines expressing mtr1-D exhibited all the characteristics of Mtr1 callus tissue. Biochemical analysis revealed that rice PDT possesses both PDT and ADT activities, with a preference for arogenate as substrate, suggesting that it functions primarily as an ADT. The wild-type enzyme is feedback regulated by Phe, whereas the mutant enzyme showed a reduced feedback sensitivity, resulting in Phe accumulation. In addition, these observations indicate that rice PDT is critical for regulating the size of the Phe pool in plant cells. Feeding external Phe to wild-type callus tissue and seedlings resulted in Trp accumulation, demonstrating a connection between Phe accumulation and Trp pool size. PMID:18487352

  9. The hedgehog pathway gene shifted functions together with the hmgcr-dependent isoprenoid biosynthetic pathway to orchestrate germ cell migration.

    Directory of Open Access Journals (Sweden)

    Girish Deshpande

    Full Text Available The Drosophila embryonic gonad is assembled from two distinct cell types, the Primordial Germ Cells (PGCs and the Somatic Gonadal Precursor cells (SGPs. The PGCs form at the posterior of blastoderm stage embryos and are subsequently carried inside the embryo during gastrulation. To reach the SGPs, the PGCs must traverse the midgut wall and then migrate through the mesoderm. A combination of local repulsive cues and attractive signals emanating from the SGPs guide migration. We have investigated the role of the hedgehog (hh pathway gene shifted (shf in directing PGC migration. shf encodes a secreted protein that facilitates the long distance transmission of Hh through the proteoglycan matrix after it is released from basolateral membranes of Hh expressing cells in the wing imaginal disc. shf is expressed in the gonadal mesoderm, and loss- and gain-of-function experiments demonstrate that it is required for PGC migration. Previous studies have established that the hmgcr-dependent isoprenoid biosynthetic pathway plays a pivotal role in generating the PGC attractant both by the SGPs and by other tissues when hmgcr is ectopically expressed. We show that production of this PGC attractant depends upon shf as well as a second hh pathway gene gγ1. Further linking the PGC attractant to Hh, we present evidence indicating that ectopic expression of hmgcr in the nervous system promotes the release/transmission of the Hh ligand from these cells into and through the underlying mesodermal cell layer, where Hh can contact migrating PGCs. Finally, potentiation of Hh by hmgcr appears to depend upon cholesterol modification.

  10. Spook and Spookier code for stage-specific components of the ecdysone biosynthetic pathway in Diptera

    DEFF Research Database (Denmark)

    Ono, Hajime; Rewitz, Kim; Shinoda, Tetsu

    2006-01-01

    is eliminated in larvae carrying mutations in molting defective (mld), a gene encoding a nuclear zinc finger protein that is required for production of ecdysone during Drosophila larval development. Intriguingly, mld is not present in the Bombyx mori genome, and we have identified only one spook homolog in both...... Bombyx and Manduca that is expressed in both embryos and larva. These studies suggest an evolutionary split between Diptera and Lepidoptera in how the ecdysone biosynthetic pathway is regulated during development....

  11. Cracking the regulatory code of biosynthetic gene clusters as a strategy for natural product discovery.

    Science.gov (United States)

    Rigali, Sébastien; Anderssen, Sinaeda; Naômé, Aymeric; van Wezel, Gilles P

    2018-01-05

    The World Health Organization (WHO) describes antibiotic resistance as "one of the biggest threats to global health, food security, and development today", as the number of multi- and pan-resistant bacteria is rising dangerously. Acquired resistance phenomena also impair antifungals, antivirals, anti-cancer drug therapy, while herbicide resistance in weeds threatens the crop industry. On the positive side, it is likely that the chemical space of natural products goes far beyond what has currently been discovered. This idea is fueled by genome sequencing of microorganisms which unveiled numerous so-called cryptic biosynthetic gene clusters (BGCs), many of which are transcriptionally silent under laboratory culture conditions, and by the fact that most bacteria cannot yet be cultivated in the laboratory. However, brute force antibiotic discovery does not yield the same results as it did in the past, and researchers have had to develop creative strategies in order to unravel the hidden potential of microorganisms such as Streptomyces and other antibiotic-producing microorganisms. Identifying the cis elements and their corresponding transcription factors(s) involved in the control of BGCs through bioinformatic approaches is a promising strategy. Theoretically, we are a few 'clicks' away from unveiling the culturing conditions or genetic changes needed to activate the production of cryptic metabolites or increase the production yield of known compounds to make them economically viable. In this opinion article, we describe and illustrate the idea beyond 'cracking' the regulatory code for natural product discovery, by presenting a series of proofs of concept, and discuss what still should be achieved to increase the rate of success of this strategy. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Deletion and Gene Expression Analyses Define the Paxilline Biosynthetic Gene Cluster in Penicillium paxilli

    Directory of Open Access Journals (Sweden)

    Emily J. Parker

    2013-08-01

    Full Text Available The indole-diterpene paxilline is an abundant secondary metabolite synthesized by Penicillium paxilli. In total, 21 genes have been identified at the PAX locus of which six have been previously confirmed to have a functional role in paxilline biosynthesis. A combination of bioinformatics, gene expression and targeted gene replacement analyses were used to define the boundaries of the PAX gene cluster. Targeted gene replacement identified seven genes, paxG, paxA, paxM, paxB, paxC, paxP and paxQ that were all required for paxilline production, with one additional gene, paxD, required for regular prenylation of the indole ring post paxilline synthesis. The two putative transcription factors, PP104 and PP105, were not co-regulated with the pax genes and based on targeted gene replacement, including the double knockout, did not have a role in paxilline production. The relationship of indole dimethylallyl transferases involved in prenylation of indole-diterpenes such as paxilline or lolitrem B, can be found as two disparate clades, not supported by prenylation type (e.g., regular or reverse. This paper provides insight into the P. paxilli indole-diterpene locus and reviews the recent advances identified in paxilline biosynthesis.

  13. Polycistronic gene expression in Aspergillus niger.

    Science.gov (United States)

    Schuetze, Tabea; Meyer, Vera

    2017-09-25

    Genome mining approaches predict dozens of biosynthetic gene clusters in each of the filamentous fungal genomes sequenced so far. However, the majority of these gene clusters still remain cryptic because they are not expressed in their natural host. Simultaneous expression of all genes belonging to a biosynthetic pathway in a heterologous host is one approach to activate biosynthetic gene clusters and to screen the metabolites produced for bioactivities. Polycistronic expression of all pathway genes under control of a single and tunable promoter would be the method of choice, as this does not only simplify cloning procedures, but also offers control on timing and strength of expression. However, polycistronic gene expression is a feature not commonly found in eukaryotic host systems, such as Aspergillus niger. In this study, we tested the suitability of the viral P2A peptide for co-expression of three genes in A. niger. Two genes descend from Fusarium oxysporum and are essential to produce the secondary metabolite enniatin (esyn1, ekivR). The third gene (luc) encodes the reporter luciferase which was included to study position effects. Expression of the polycistronic gene cassette was put under control of the Tet-On system to ensure tunable gene expression in A. niger. In total, three polycistronic expression cassettes which differed in the position of luc were constructed and targeted to the pyrG locus in A. niger. This allowed direct comparison of the luciferase activity based on the position of the luciferase gene. Doxycycline-mediated induction of the Tet-On expression cassettes resulted in the production of one long polycistronic mRNA as proven by Northern analyses, and ensured comparable production of enniatin in all three strains. Notably, gene position within the polycistronic expression cassette matters, as, luciferase activity was lowest at position one and had a comparable activity at positions two and three. The P2A peptide can be used to express at

  14. Molecular characterization of a fungal gene paralogue of the penicillin penDE gene of Penicillium chrysogenum

    Science.gov (United States)

    2009-01-01

    Background Penicillium chrysogenum converts isopenicillin N (IPN) into hydrophobic penicillins by means of the peroxisomal IPN acyltransferase (IAT), which is encoded by the penDE gene. In silico analysis of the P. chrysogenum genome revealed the presence of a gene, Pc13g09140, initially described as paralogue of the IAT-encoding penDE gene. We have termed this gene ial because it encodes a protein with high similarity to IAT (IAL for IAT-Like). We have conducted an investigation to characterize the ial gene and to determine the role of the IAL protein in the penicillin biosynthetic pathway. Results The IAL contains motifs characteristic of the IAT such as the processing site, but lacks the peroxisomal targeting sequence ARL. Null ial mutants and overexpressing strains indicated that IAL lacks acyltransferase (penicillin biosynthetic) and amidohydrolase (6-APA forming) activities in vivo. When the canonical ARL motif (leading to peroxisomal targeting) was added to the C-terminus of the IAL protein (IALARL) by site-directed mutagenesis, no penicillin biosynthetic activity was detected. Since the IAT is only active after an accurate self-processing of the preprotein into α and β subunits, self-processing of the IAL was tested in Escherichia coli. Overexpression experiments and SDS-PAGE analysis revealed that IAL is also self-processed in two subunits, but despite the correct processing, the enzyme remained inactive in vitro. Conclusion No activity related to the penicillin biosynthesis was detected for the IAL. Sequence comparison among the P. chrysogenum IAL, the A. nidulans IAL homologue and the IAT, revealed that the lack of enzyme activity seems to be due to an alteration of the essential Ser309 in the thioesterase active site. Homologues of the ial gene have been found in many other ascomycetes, including non-penicillin producers. Our data suggest that like in A. nidulans, the ial and penDE genes might have been formed from a single ancestral gene that became

  15. Isolation and Biosynthetic Analysis of Haliamide, a New PKS-NRPS Hybrid Metabolite from the Marine Myxobacterium Haliangium ochraceum

    Directory of Open Access Journals (Sweden)

    Yuwei Sun

    2016-01-01

    Full Text Available Myxobacteria of marine origin are rare and hard-to-culture microorganisms, but they genetically harbor high potential to produce novel antibiotics. An extensive investigation on the secondary metabolome of the unique marine myxobacterium Haliangium ochraceum SMP-2 led to the isolation of a new polyketide-nonribosomal peptide hybrid product, haliamide (1. Its structure was elucidated by spectroscopic analyses including NMR and HR-MS. Haliamide (1 showed cytotoxicity against HeLa-S3 cells with IC50 of 12 μM. Feeding experiments were performed to identify the biosynthetic building blocks of 1, revealing one benzoate, one alanine, two propionates, one acetate and one acetate-derived terminal methylene. The biosynthetic gene cluster of haliamide (hla, 21.7 kbp was characterized through the genome mining of the producer, allowing us to establish a model for the haliamide biosynthesis. The sulfotransferase (ST-thioesterase (TE domains encoded in hlaB appears to be responsible for the terminal alkene formation via decarboxylation.

  16. Gene transcript profiles of the TIA biosynthetic pathway in response to ethylene and copper reveal their interactive role in modulating TIA biosynthesis in Catharanthus roseus.

    Science.gov (United States)

    Pan, Ya-Jie; Liu, Jia; Guo, Xiao-Rui; Zu, Yuan-Gang; Tang, Zhong-Hua

    2015-05-01

    Research on transcriptional regulation of terpenoid indole alkaloid (TIA) biosynthesis of the medicinal plant, Catharanthus roseus, has largely been focused on gene function and not clustering analysis of multiple genes at the transcript level. Here, more than ten key genes encoding key enzyme of alkaloid synthesis in TIA biosynthetic pathways were chosen to investigate the integrative responses to exogenous elicitor ethylene and copper (Cu) at both transcriptional and metabolic levels. The ethylene-induced gene transcripts in leaves and roots, respectively, were subjected to principal component analysis (PCA) and the results showed the overall expression of TIA pathway genes indicated as the Q value followed a standard normal distribution after ethylene treatments. Peak gene expression was at 15-30 μM of ethephon, and the pre-mature leaf had a higher Q value than the immature or mature leaf and root. Treatment with elicitor Cu found that Cu up-regulated overall TIA gene expression more in roots than in leaves. The combined effects of Cu and ethephon on TIA gene expression were stronger than their separate effects. It has been documented that TIA gene expression is tightly regulated by the transcriptional factor (TF) ethylene responsive factor (ERF) and mitogen-activated protein kinase (MAPK) cascade. The loading plot combination with correlation analysis for the genes of C. roseus showed that expression of the MPK gene correlated with strictosidine synthase (STR) and strictosidine b-D-glucosidase(SGD). In addition, ERF expression correlated with expression of secologanin synthase (SLS) and tryptophan decarboxylase (TDC), specifically in roots, whereas MPK and myelocytomatosis oncogene (MYC) correlated with STR and SGD genes. In conclusion, the ERF regulates the upstream pathway genes in response to heavy metal Cu mainly in C. roseus roots, while the MPK mainly participates in regulating the STR gene in response to ethylene in pre-mature leaf. Interestingly, the

  17. Key roles of Arf small G proteins and biosynthetic trafficking for animal development.

    Science.gov (United States)

    Rodrigues, Francisco F; Harris, Tony J C

    2017-04-14

    Although biosynthetic trafficking can function constitutively, it also functions specifically for certain developmental processes. These processes require either a large increase to biosynthesis or the biosynthesis and targeted trafficking of specific players. We review the conserved molecular mechanisms that direct biosynthetic trafficking, and discuss how their genetic disruption affects animal development. Specifically, we consider Arf small G proteins, such as Arf1 and Sar1, and their coat effectors, COPI and COPII, and how these proteins promote biosynthetic trafficking for cleavage of the Drosophila embryo, the growth of neuronal dendrites and synapses, extracellular matrix secretion for bone development, lumen development in epithelial tubes, notochord and neural tube development, and ciliogenesis. Specific need for the biosynthetic trafficking system is also evident from conserved CrebA/Creb3-like transcription factors increasing the expression of secretory machinery during several of these developmental processes. Moreover, dysfunctional trafficking leads to a range of developmental syndromes.

  18. Construction of a controllable β-carotene biosynthetic pathway by decentralized assembly strategy in Saccharomyces cerevisiae.

    Science.gov (United States)

    Xie, Wenping; Liu, Min; Lv, Xiaomei; Lu, Wenqiang; Gu, Jiali; Yu, Hongwei

    2014-01-01

    Saccharomyces cerevisiae is an important platform organism for the synthesis of a great number of natural products. However, the assembly of controllable and genetically stable heterogeneous biosynthetic pathways in S. cerevisiae still remains a significant challenge. Here, we present a strategy for reconstructing controllable multi-gene pathways by employing the GAL regulatory system. A set of marker recyclable integrative plasmids (pMRI) was designed for decentralized assembly of pathways. As proof-of-principle, a controllable β-carotene biosynthesis pathway (∼16 kb) was reconstructed and optimized by repeatedly using GAL10-GAL1 bidirectional promoters with high efficiency (80-100%). By controling the switch time of the pathway, production of 11 mg/g DCW of total carotenoids (72.57 mg/L) and 7.41 mg/g DCW of β-carotene was achieved in shake-flask culture. In addition, the engineered yeast strain exhibited high genetic stability after 20 generations of subculture. The results demonstrated a controllable and genetically stable biosynthetic pathway capable of increasing the yield of target products. Furthermore, the strategy presented in this study could be extended to construct other pathways in S. cerevisisae. © 2013 Wiley Periodicals, Inc.

  19. Expression of cocoa genes in Saccharomyces cerevisiae improves cocoa butter production

    DEFF Research Database (Denmark)

    Wei, Yongjun; Bergenholm, David; Gossing, Michael

    2018-01-01

    Background: Cocoa butter (CB) extracted from cocoa beans (Theobroma cacao) is the main raw material for chocolate production, but CB supply is insufficient due to the increased chocolate demand and limited CB production. CB is mainly composed of three different kinds of triacylglycerols (TAGs), 1......), and it is essential to modulate the yeast TAG biosynthetic pathway for higher CBL production.Results: We cloned seven GPAT genes and three LPAT genes from cocoa cDNA, in order to screen for CBL biosynthetic gene candidates. By expressing these cloned cocoa genes and two synthesized cocoa DGAT genes in S. cerevisiae......, we successfully increased total fatty acid production, TAG production and CBL production in some of the strains. In the best producer, the potential CBL content was eightfold higher than the control strain, suggesting the cocoa genes expressed in this strain were functional and might be responsible...

  20. Expression profile of genes coding for carotenoid biosynthetic ...

    Indian Academy of Sciences (India)

    3Department of Biotechnology, School of Life Sciences, Assam University, Silchar 788 011, India. 4Reliance Industries ... mellitus, and helps to maintain prostate health (Stacewicz- ... mental stages to establish gene-to-metabolite links in high.

  1. Biosynthesis of Akaeolide and Lorneic Acids and Annotation of Type I Polyketide Synthase Gene Clusters in the Genome of Streptomyces sp. NPS554

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    Tao Zhou

    2015-01-01

    Full Text Available The incorporation pattern of biosynthetic precursors into two structurally unique polyketides, akaeolide and lorneic acid A, was elucidated by feeding experiments with 13C-labeled precursors. In addition, the draft genome sequence of the producer, Streptomyces sp. NPS554, was performed and the biosynthetic gene clusters for these polyketides were identified. The putative gene clusters contain all the polyketide synthase (PKS domains necessary for assembly of the carbon skeletons. Combined with the 13C-labeling results, gene function prediction enabled us to propose biosynthetic pathways involving unusual carbon-carbon bond formation reactions. Genome analysis also indicated the presence of at least ten orphan type I PKS gene clusters that might be responsible for the production of new polyketides.

  2. The flavonoid biosynthetic pathway in plants: function and evolution

    International Nuclear Information System (INIS)

    Koes, R.E.; Quattrocchio, F.; Mol, J.N.M.

    1994-01-01

    Flavonoids are a class of low molecular weight phenolic compounds that is widely distributed in the plant kingdom. They exhibit a diverse spectrum of biological functions and play an important role in the interaction between plants and their environment. Flavonoids not only protect the plant from the harmful effects of UV irradiation but also play a crucial role in the sexual reproduction process. A special class of flavonoid polymers, the tannins, plays a structural role in the plant. Yet other classes of flavonoids, flavonols and anthocyanins, have been implicated in the attraction of pollinators. Certain flavonoids participate in the interaction between plants and other organisms such as symbiotic bacteria and parasites. This raises the intriguing question as to how these different compounds arose and evolved. Based on taxonomy and molecular analysis of gene expression patterns it is possible to deduce a putative sequence of acquisition of the different branches of the biosynthetic pathway and their regulators. (author)

  3. The flavonoid biosynthetic pathway in plants: function and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Koes, R. E.; Quattrocchio, F.; Mol, J. N.M. [Department of Genetics, Institute for Molecular Biological Sciences, Vrije Universiteit, BioCentrum Amsterdam, De Boelelaan 1087, 1081HV, Amsterdam (Netherlands)

    1994-07-01

    Flavonoids are a class of low molecular weight phenolic compounds that is widely distributed in the plant kingdom. They exhibit a diverse spectrum of biological functions and play an important role in the interaction between plants and their environment. Flavonoids not only protect the plant from the harmful effects of UV irradiation but also play a crucial role in the sexual reproduction process. A special class of flavonoid polymers, the tannins, plays a structural role in the plant. Yet other classes of flavonoids, flavonols and anthocyanins, have been implicated in the attraction of pollinators. Certain flavonoids participate in the interaction between plants and other organisms such as symbiotic bacteria and parasites. This raises the intriguing question as to how these different compounds arose and evolved. Based on taxonomy and molecular analysis of gene expression patterns it is possible to deduce a putative sequence of acquisition of the different branches of the biosynthetic pathway and their regulators. (author)

  4. Metabolic engineering to simultaneously activate anthocyanin and proanthocyanidin biosynthetic pathways in Nicotiana spp.

    Directory of Open Access Journals (Sweden)

    Sandra Fresquet-Corrales

    Full Text Available Proanthocyanidins (PAs, or condensed tannins, are powerful antioxidants that remove harmful free oxygen radicals from cells. To engineer the anthocyanin and proanthocyanidin biosynthetic pathways to de novo produce PAs in two Nicotiana species, we incorporated four transgenes to the plant chassis. We opted to perform a simultaneous transformation of the genes linked in a multigenic construct rather than classical breeding or retransformation approaches. We generated a GoldenBraid 2.0 multigenic construct containing two Antirrhinum majus transcription factors (AmRosea1 and AmDelila to upregulate the anthocyanin pathway in combination with two Medicago truncatula genes (MtLAR and MtANR to produce the enzymes that will derivate the biosynthetic pathway to PAs production. Transient and stable transformation of Nicotiana benthamiana and Nicotiana tabacum with the multigenic construct were respectively performed. Transient expression experiments in N. benthamiana showed the activation of the anthocyanin pathway producing a purple color in the agroinfiltrated leaves and also the effective production of 208.5 nmol (- catechin/g FW and 228.5 nmol (- epicatechin/g FW measured by the p-dimethylaminocinnamaldehyde (DMACA method. The integration capacity of the four transgenes, their respective expression levels and their heritability in the second generation were analyzed in stably transformed N. tabacum plants. DMACA and phoroglucinolysis/HPLC-MS analyses corroborated the activation of both pathways and the effective production of PAs in T0 and T1 transgenic tobacco plants up to a maximum of 3.48 mg/g DW. The possible biotechnological applications of the GB2.0 multigenic approach in forage legumes to produce "bloat-safe" plants and to improve the efficiency of conversion of plant protein into animal protein (ruminal protein bypass are discussed.

  5. A R2R3-MYB transcription factor regulates the flavonol biosynthetic pathway in a traditional Chinese medicinal plant, Epimedium sagittatum

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    Wenjun Huang

    2016-07-01

    Full Text Available Flavonols as plant secondary metabolites with vital roles in plant development and defense against UV light, have been demonstrated to be the main bioactive components in the genus Epimedium plants, several species of which are used as materials for Herba Epimedii, an important traditional Chinese medicine. The flavonol biosynthetic pathway genes had been already isolated from E. sagittatum, but a R2R3-MYB transcription factor regulating the flavonol synthesis has not been functionally characterized so far in Epimedium plants. In this study, we isolated and characterized the R2R3-MYB transcription factor EsMYBF1 involved in regulation of the flavonol biosynthetic pathway from E. sagittatum. Sequence analysis indicated that EsMYBF1 belongs to the subgroup 7 of R2R3-MYB family which contains the flavonol-specific MYB regulators identified to date. Transient reporter assay showed that EsMYBF1 strongly activated the promoters of EsF3H (flavanone 3-hydroxylase and EsFLS (flavonol synthase, but not the promoters of EsDFRs (dihydroflavonol 4-reductase and EsANS (anthocyanidin synthase in transiently transformed Nicotiana benthamiana leaves. Both yeast two-hybrid assay and transient reporter assay validated EsMYBF1 to be independent of EsTT8, or AtTT8 bHLH regulators of the flavonoid pathway as cofactors. Ectopic expression of EsMYBF1 in transgenic tobacco resulted in the increased flavonol content and the decreased anthocyanin content in flowers. Correspondingly, the structural genes involved in flavonol synthesis were upregulated in the EsMYBF1 overexpression lines, including NtCHS (chalcone synthase, NtCHI (chalcone isomerase, NtF3H and NtFLS, whereas the late biosynthetic genes of the anthocyanin pathway (NtDFR and NtANS were remarkably downregulated, compared to the controls. These results suggest that EsMYBF1 is a flavonol-specific R2R3-MYB regulator, and involved in regulation of the biosynthesis of the flavonol-derived bioactive components in E

  6. A nitrous acid biosynthetic pathway for diazo group formation in bacteria.

    Science.gov (United States)

    Sugai, Yoshinori; Katsuyama, Yohei; Ohnishi, Yasuo

    2016-02-01

    Although some diazo compounds have bioactivities of medicinal interest, little is known about diazo group formation in nature. Here we describe an unprecedented nitrous acid biosynthetic pathway responsible for the formation of a diazo group in the biosynthesis of the ortho-diazoquinone secondary metabolite cremeomycin in Streptomyces cremeus. This finding provides important insights into the biosynthetic pathways not only for diazo compounds but also for other naturally occurring compounds containing nitrogen-nitrogen bonds.

  7. [Advance in flavonoids biosynthetic pathway and synthetic biology].

    Science.gov (United States)

    Zou, Li-Qiu; Wang, Cai-Xia; Kuang, Xue-Jun; Li, Ying; Sun, Chao

    2016-11-01

    Flavonoids are the valuable components in medicinal plants, which possess a variety of pharmacological activities, including anti-tumor, antioxidant and anti-inflammatory activities. There is an unambiguous understanding about flavonoids biosynthetic pathway, that is,2S-flavanones including naringenin and pinocembrin are the skeleton of other flavonoids and they can transform to other flavonoids through branched metabolic pathway. Elucidation of the flavonoids biosynthetic pathway lays a solid foundation for their synthetic biology. A few flavonoids have been produced in Escherichia coli or yeast with synthetic biological technologies, such as naringenin, pinocembrin and fisetin. Synthetic biology will provide a new way to get valuable flavonoids and promote the research and development of flavonoid drugs and health products, making flavonoids play more important roles in human diet and health. Copyright© by the Chinese Pharmaceutical Association.

  8. Methamphetamine-induced neuronal protein NAT8L is the NAA biosynthetic enzyme: implications for specialized acetyl coenzyme A metabolism in the CNS.

    Science.gov (United States)

    Ariyannur, Prasanth S; Moffett, John R; Manickam, Pachiappan; Pattabiraman, Nagarajan; Arun, Peethambaran; Nitta, Atsumi; Nabeshima, Toshitaka; Madhavarao, Chikkathur N; Namboodiri, Aryan M A

    2010-06-04

    N-acetylaspartate (NAA) is a concentrated, neuron-specific brain metabolite routinely used as a magnetic resonance spectroscopy marker for brain injury and disease. Despite decades of research, the functional roles of NAA remain unclear. Biochemical investigations over several decades have associated NAA with myelin lipid synthesis and energy metabolism. However, studies have been hampered by an inability to identify the gene for the NAA biosynthetic enzyme aspartate N-acetyltransferase (Asp-NAT). A very recent report has identified Nat8l as the gene encoding Asp-NAT and confirmed that the only child diagnosed with a lack of NAA on brain magnetic resonance spectrograms has a 19-bp deletion in this gene. Based on in vitro Nat8l expression studies the researchers concluded that many previous biochemical investigations have been technically flawed and that NAA may not be associated with brain energy or lipid metabolism. In studies done concurrently in our laboratory we have demonstrated via cloning, expression, specificity for acetylation of aspartate, responsiveness to methamphetamine treatment, molecular modeling and comparative immunolocalization that NAT8L is the NAA biosynthetic enzyme Asp-NAT. We conclude that NAA is a major storage and transport form of acetyl coenzyme A specific to the nervous system, thus linking it to both lipid synthesis and energy metabolism. Published by Elsevier B.V.

  9. Functional Genome Mining for Metabolites Encoded by Large Gene Clusters through Heterologous Expression of a Whole-Genome Bacterial Artificial Chromosome Library in Streptomyces spp.

    Science.gov (United States)

    Xu, Min; Wang, Yemin; Zhao, Zhilong; Gao, Guixi; Huang, Sheng-Xiong; Kang, Qianjin; He, Xinyi; Lin, Shuangjun; Pang, Xiuhua; Deng, Zixin

    2016-01-01

    ABSTRACT Genome sequencing projects in the last decade revealed numerous cryptic biosynthetic pathways for unknown secondary metabolites in microbes, revitalizing drug discovery from microbial metabolites by approaches called genome mining. In this work, we developed a heterologous expression and functional screening approach for genome mining from genomic bacterial artificial chromosome (BAC) libraries in Streptomyces spp. We demonstrate mining from a strain of Streptomyces rochei, which is known to produce streptothricins and borrelidin, by expressing its BAC library in the surrogate host Streptomyces lividans SBT5, and screening for antimicrobial activity. In addition to the successful capture of the streptothricin and borrelidin biosynthetic gene clusters, we discovered two novel linear lipopeptides and their corresponding biosynthetic gene cluster, as well as a novel cryptic gene cluster for an unknown antibiotic from S. rochei. This high-throughput functional genome mining approach can be easily applied to other streptomycetes, and it is very suitable for the large-scale screening of genomic BAC libraries for bioactive natural products and the corresponding biosynthetic pathways. IMPORTANCE Microbial genomes encode numerous cryptic biosynthetic gene clusters for unknown small metabolites with potential biological activities. Several genome mining approaches have been developed to activate and bring these cryptic metabolites to biological tests for future drug discovery. Previous sequence-guided procedures relied on bioinformatic analysis to predict potentially interesting biosynthetic gene clusters. In this study, we describe an efficient approach based on heterologous expression and functional screening of a whole-genome library for the mining of bioactive metabolites from Streptomyces. The usefulness of this function-driven approach was demonstrated by the capture of four large biosynthetic gene clusters for metabolites of various chemical types, including

  10. Anthocyanin accumulation and molecular analysis of anthocyanin biosynthesis-associated genes in eggplant (Solanum melongena L.).

    Science.gov (United States)

    Zhang, Yanjie; Hu, Zongli; Chu, Guihua; Huang, Cheng; Tian, Shibing; Zhao, Zhiping; Chen, Guoping

    2014-04-02

    Eggplant (Solanum melongena L.) is an edible fruit vegetable cultivated and consumed worldwide. The purple eggplant is more eye-catching and popular for the health-promoting anthocyanins contained in the fruit skin. Two kinds of anthocyanin were separated and identified from purple cultivar (Zi Chang) by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms of anthocyanin accumulation in eggplant, the transcripts of anthocyanin biosynthetic and regulatory genes were analyzed in the fruit skin and the flesh of the purple cultivar and the white cultivar (Bai Xue). Compared with the other tissues, SmMYB1 and all anthocyanin biosynthetic genes except PAL were dramatically upregulated in the fruit skin of the purple cultivar. Overexpression of SmMYB1 activated abundant anthocyanin accumulation in the regenerating shoots of eggplant. These results prove that transcriptional activation of SmMYB1 accounts for constitutive upregulation of most anthocyanin biosynthetic genes and the onset of anthocyanin biosynthesis in the purple cultivar.

  11. Arabidopsis brassinosteroid biosynthetic mutant dwarf7-1 exhibits slower rates of cell division and shoot induction

    Directory of Open Access Journals (Sweden)

    Schulz Burkhard

    2010-12-01

    Full Text Available Abstract Background Plant growth depends on both cell division and cell expansion. Plant hormones, including brassinosteroids (BRs, are central to the control of these two cellular processes. Despite clear evidence that BRs regulate cell elongation, their roles in cell division have remained elusive. Results Here, we report results emphasizing the importance of BRs in cell division. An Arabidopsis BR biosynthetic mutant, dwarf7-1, displayed various characteristics attributable to slower cell division rates. We found that the DWARF4 gene which encodes for an enzyme catalyzing a rate-determining step in the BR biosynthetic pathways, is highly expressed in the actively dividing callus, suggesting that BR biosynthesis is necessary for dividing cells. Furthermore, dwf7-1 showed noticeably slower rates of callus growth and shoot induction relative to wild-type control. Flow cytometric analyses of the nuclei derived from either calli or intact roots revealed that the cell division index, which was represented as the ratio of cells at the G2/M vs. G1 phases, was smaller in dwf7-1 plants. Finally, we found that the expression levels of the genes involved in cell division and shoot induction, such as PROLIFERATING CELL NUCLEAR ANTIGEN2 (PCNA2 and ENHANCER OF SHOOT REGENERATION2 (ESR2, were also lower in dwf7-1 as compared with wild type. Conclusions Taken together, results of callus induction, shoot regeneration, flow cytometry, and semi-quantitative RT-PCR analysis suggest that BRs play important roles in both cell division and cell differentiation in Arabidopsis.

  12. Carotenoid Biosynthetic Pathways Are Regulated by a Network of Multiple Cascades of Alternative Sigma Factors in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Rai, Ashutosh Kumar; Dubey, Ashutosh Prakash; Kumar, Santosh; Dutta, Debashis; Mishra, Mukti Nath; Singh, Bhupendra Narain; Tripathi, Anil Kumar

    2016-11-01

    Carotenoids constitute an important component of the defense system against photooxidative stress in bacteria. In Azospirillum brasilense Sp7, a nonphotosynthetic rhizobacterium, carotenoid synthesis is controlled by a pair of extracytoplasmic function sigma factors (RpoEs) and their cognate zinc-binding anti-sigma factors (ChrRs). Its genome harbors two copies of the gene encoding geranylgeranyl pyrophosphate synthase (CrtE), the first critical step in the carotenoid biosynthetic pathway in bacteria. Inactivation of each of two crtE paralogs found in A. brasilense caused reduction in carotenoid content, suggesting their involvement in carotenoid synthesis. However, the effect of crtE1 deletion was more pronounced than that of crtE2 deletion. Out of the five paralogs of rpoH in A. brasilense, overexpression of rpoH1 and rpoH2 enhanced carotenoid synthesis. Promoters of crtE2 and rpoH2 were found to be dependent on RpoH2 and RpoE1, respectively. Using a two-plasmid system in Escherichia coli, we have shown that the crtE2 gene of A. brasilense Sp7 is regulated by two cascades of sigma factors: one consisting of RpoE1and RpoH2 and the other consisting of RpoE2 and RpoH1. In addition, expression of crtE1 was upregulated indirectly by RpoE1 and RpoE2. This study shows, for the first time in any carotenoid-producing bacterium, that the regulation of carotenoid biosynthetic pathway involves a network of multiple cascades of alternative sigma factors. Carotenoids play a very important role in coping with photooxidative stress in prokaryotes and eukaryotes. Although extracytoplasmic function (ECF) sigma factors are known to directly regulate the expression of carotenoid biosynthetic genes in bacteria, regulation of carotenoid biosynthesis by one or multiple cascades of sigma factors had not been reported. This study provides the first evidence of the involvement of multiple cascades of sigma factors in the regulation of carotenoid synthesis in any bacterium by showing the

  13. Structural, evolutionary and genetic analysis of the histidine biosynthetic "core" in the genus Burkholderia.

    Science.gov (United States)

    Papaleo, Maria Cristiana; Russo, Edda; Fondi, Marco; Emiliani, Giovanni; Frandi, Antonio; Brilli, Matteo; Pastorelli, Roberta; Fani, Renato

    2009-12-01

    In this work a detailed analysis of the structure, the expression and the organization of his genes belonging to the core of histidine biosynthesis (hisBHAF) in 40 newly determined and 13 available sequences of Burkholderia strains was carried out. Data obtained revealed a strong conservation of the structure and organization of these genes through the entire genus. The phylogenetic analysis showed the monophyletic origin of this gene cluster and indicated that it did not undergo horizontal gene transfer events. The analysis of the intergenic regions, based on the substitution rate, entropy plot and bendability suggested the existence of a putative transcription promoter upstream of hisB, that was supported by the genetic analysis that showed that this cluster was able to complement Escherichia colihisA, hisB, and hisF mutations. Moreover, a preliminary transcriptional analysis and the analysis of microarray data revealed that the expression of the his core was constitutive. These findings are in agreement with the fact that the entire Burkholderiahis operon is heterogeneous, in that it contains "alien" genes apparently not involved in histidine biosynthesis. Besides, they also support the idea that the proteobacterial his operon was piece-wisely assembled, i.e. through accretion of smaller units containing only some of the genes (eventually together with their own promoters) involved in this biosynthetic route. The correlation existing between the structure, organization and regulation of his "core" genes and the function(s) they perform in cellular metabolism is discussed.

  14. Phase variable O antigen biosynthetic genes control expression of the major protective antigen and bacteriophage receptor in Vibrio cholerae O1.

    Directory of Open Access Journals (Sweden)

    Kimberley D Seed

    2012-09-01

    Full Text Available The Vibrio cholerae lipopolysaccharide O1 antigen is a major target of bacteriophages and the human immune system and is of critical importance for vaccine design. We used an O1-specific lytic bacteriophage as a tool to probe the capacity of V. cholerae to alter its O1 antigen and identified a novel mechanism by which this organism can modulate O antigen expression and exhibit intra-strain heterogeneity. We identified two phase variable genes required for O1 antigen biosynthesis, manA and wbeL. manA resides outside of the previously recognized O1 antigen biosynthetic locus, and encodes for a phosphomannose isomerase critical for the initial step in O1 antigen biosynthesis. We determined that manA and wbeL phase variants are attenuated for virulence, providing functional evidence to further support the critical role of the O1 antigen for infectivity. We provide the first report of phase variation modulating O1 antigen expression in V. cholerae, and show that the maintenance of these phase variable loci is an important means by which this facultative pathogen can generate the diverse subpopulations of cells needed for infecting the host intestinal tract and for escaping predation by an O1-specific phage.

  15. Flavonoid Biosynthesis Genes Putatively Identified in the Aromatic Plant Polygonum minus via Expressed Sequences Tag (EST Analysis

    Directory of Open Access Journals (Sweden)

    Zamri Zainal

    2012-02-01

    Full Text Available P. minus is an aromatic plant, the leaf of which is widely used as a food additive and in the perfume industry. The leaf also accumulates secondary metabolites that act as active ingredients such as flavonoid. Due to limited genomic and transcriptomic data, the biosynthetic pathway of flavonoids is currently unclear. Identification of candidate genes involved in the flavonoid biosynthetic pathway will significantly contribute to understanding the biosynthesis of active compounds. We have constructed a standard cDNA library from P. minus leaves, and two normalized full-length enriched cDNA libraries were constructed from stem and root organs in order to create a gene resource for the biosynthesis of secondary metabolites, especially flavonoid biosynthesis. Thus, large‑scale sequencing of P. minus cDNA libraries identified 4196 expressed sequences tags (ESTs which were deposited in dbEST in the National Center of Biotechnology Information (NCBI. From the three constructed cDNA libraries, 11 ESTs encoding seven genes were mapped to the flavonoid biosynthetic pathway. Finally, three flavonoid biosynthetic pathway-related ESTs chalcone synthase, CHS (JG745304, flavonol synthase, FLS (JG705819 and leucoanthocyanidin dioxygenase, LDOX (JG745247 were selected for further examination by quantitative RT-PCR (qRT-PCR in different P. minus organs. Expression was detected in leaf, stem and root. Gene expression studies have been initiated in order to better understand the underlying physiological processes.

  16. Polyketide synthase chemistry does not direct biosynthetic divergence between 9- and 10-membered enediynes

    Science.gov (United States)

    Horsman, Geoff P.; Chen, Yihua; Thorson, Jon S.; Shen, Ben

    2010-01-01

    Enediynes are potent antitumor antibiotics that are classified as 9- or 10-membered according to the size of the enediyne core structure. However, almost nothing is known about enediyne core biosynthesis, and the determinants of 9- versus 10-membered enediyne core biosynthetic divergence remain elusive. Previous work identified enediyne-specific polyketide synthases (PKSEs) that can be phylogenetically distinguished as being involved in 9- versus 10-membered enediyne biosynthesis, suggesting that biosynthetic divergence might originate from differing PKSE chemistries. Recent in vitro studies have identified several compounds produced by the PKSE and associated thioesterase (TE), but condition-dependent product profiles make it difficult to ascertain a true catalytic difference between 9- and 10-membered PKSE-TE systems. Here we report that PKSE chemistry does not direct 9- versus 10-membered enediyne core biosynthetic divergence as revealed by comparing the products from three 9-membered and two 10-membered PKSE-TE systems under identical conditions using robust in vivo assays. Three independent experiments support a common catalytic function for 9- and 10-membered PKSEs by the production of a heptaene metabolite from: (i) all five cognate PKSE-TE pairs in Escherichia coli; (ii) the C-1027 and calicheamicin cognate PKSE-TEs in Streptomyces lividans K4-114; and (iii) selected native producers of both 9- and 10-membered enediynes. Furthermore, PKSEs and TEs from different 9- and 10-membered enediyne biosynthetic machineries are freely interchangeable, revealing that 9- versus 10-membered enediyne core biosynthetic divergence occurs beyond the PKSE-TE level. These findings establish a starting point for determining the origins of this biosynthetic divergence. PMID:20534556

  17. Reconstruction of cytosolic fumaric acid biosynthetic pathways in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Xu Guoqiang

    2012-02-01

    Full Text Available Abstract Background Fumaric acid is a commercially important component of foodstuffs, pharmaceuticals and industrial materials, yet the current methods of production are unsustainable and ecologically destructive. Results In this study, the fumarate biosynthetic pathway involving reductive reactions of the tricarboxylic acid cycle was exogenously introduced in S. cerevisiae by a series of simple genetic modifications. First, the Rhizopus oryzae genes for malate dehydrogenase (RoMDH and fumarase (RoFUM1 were heterologously expressed. Then, expression of the endogenous pyruvate carboxylase (PYC2 was up-regulated. The resultant yeast strain, FMME-001 ↑PYC2 + ↑RoMDH, was capable of producing significantly higher yields of fumarate in the glucose medium (3.18 ± 0.15 g liter-1 than the control strain FMME-001 empty vector. Conclusions The results presented here provide a novel strategy for fumarate biosynthesis, which represents an important advancement in producing high yields of fumarate in a sustainable and ecologically-friendly manner.

  18. A gene encoding an abscisic acid biosynthetic enzyme (LsNCED4) collocates with the high temperature germination locus Htg6.1 in lettuce (Lactuca sp.).

    Science.gov (United States)

    Argyris, Jason; Truco, María José; Ochoa, Oswaldo; McHale, Leah; Dahal, Peetambar; Van Deynze, Allen; Michelmore, Richard W; Bradford, Kent J

    2011-01-01

    Thermoinhibition, or failure of seeds to germinate when imbibed at warm temperatures, can be a significant problem in lettuce (Lactuca sativa L.) production. The reliability of stand establishment would be improved by increasing the ability of lettuce seeds to germinate at high temperatures. Genes encoding germination- or dormancy-related proteins were mapped in a recombinant inbred line population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. This revealed several candidate genes that are located in the genomic regions containing quantitative trait loci (QTLs) associated with temperature and light requirements for germination. In particular, LsNCED4, a temperature-regulated gene in the biosynthetic pathway for abscisic acid (ABA), a germination inhibitor, mapped to the center of a previously detected QTL for high temperature germination (Htg6.1) from UC96US23. Three sets of sister BC(3)S(2) near-isogenic lines (NILs) that were homozygous for the UC96US23 allele of LsNCED4 at Htg6.1 were developed by backcrossing to cv. Salinas and marker-assisted selection followed by selfing. The maximum temperature for germination of NIL seed lots with the UC96US23 allele at LsNCED4 was increased by 2-3°C when compared with sister NIL seed lots lacking the introgression. In addition, the expression of LsNCED4 was two- to threefold lower in the former NIL lines as compared to expression in the latter. Together, these data strongly implicate LsNCED4 as the candidate gene responsible for the Htg6.1 phenotype and indicate that decreased ABA biosynthesis at high imbibition temperatures is a major factor responsible for the increased germination thermotolerance of UC96US23 seeds.

  19. Elucidating the biosynthetic and regulatory mechanisms of flavonoid-derived bioactive components in Epimedium sagittatum

    Directory of Open Access Journals (Sweden)

    Wenjun eHuang

    2015-09-01

    Full Text Available Herba epimedii (Epimedium, a traditional Chinese medicine, has been widely used as a kidney tonic and antirheumatic medicine for thousands of years. In Epimedium, flavonoids have been demonstrated to be the main bioactive components (BCs. However, the molecular biosynthetic and regulatory mechanisms of flavonoid-derived BCs remain obscure. In this study, we isolated twelve structural genes and two putative transcription factors (TFs in the flavonoid pathway. Phytochemical analysis showed that the total content of four representative BCs (epimedin A, B, C and icariin decreased slightly or dramatically in two lines of E. sagittatum during leaf development. Transcriptional analysis revealed that two R2R3-MYB TFs (EsMYBA1 and EsMYBF1, together with a bHLH TF (EsGL3 and WD40 protein (EsTTG1, were supposed to coordinately regulate the anthocyanin and flavonol-derived BCs biosynthesis in leaves. Overexpression of EsFLS (flavonol synthase in tobacco resulted in increased flavonols content and decreased anthocyanins content in flowers. Moreover, EsMYB12 negatively correlated with the accumulation of the four BCs, and might act as a transcriptional repressor in the flavonoid pathway. Therefore, the anthocyanin pathway may coordinate with the flavonol-derived BCs pathway in Epimedium leaves. A better understanding of the flavonoid biosynthetic and regulatory mechanisms in E. sagittatum will facilitate functional characterization, metabolic engineering and molecular breeding studies of Epimedium species.

  20. Analysis of flavonoids and the flavonoid structural genes in brown fiber of upland cotton.

    Directory of Open Access Journals (Sweden)

    Hongjie Feng

    Full Text Available BACKGROUND: As a result of changing consumer preferences, cotton (Gossypium Hirsutum L. from varieties with naturally colored fibers is becoming increasingly sought after in the textile industry. The molecular mechanisms leading to colored fiber development are still largely unknown, although it is expected that the color is derived from flavanoids. EXPERIMENTAL DESIGN: Firstly, four key genes of the flavonoid biosynthetic pathway in cotton (GhC4H, GhCHS, GhF3'H, and GhF3'5'H were cloned and studied their expression profiles during the development of brown- and white cotton fibers by QRT-PCR. And then, the concentrations of four components of the flavonoid biosynthetic pathway, naringenin, quercetin, kaempferol and myricetin in brown- and white fibers were analyzed at different developmental stages by HPLC. RESULT: The predicted proteins of the four flavonoid structural genes corresponding to these genes exhibit strong sequence similarity to their counterparts in various plant species. Transcript levels for all four genes were considerably higher in developing brown fibers than in white fibers from a near isogenic line (NIL. The contents of four flavonoids (naringenin, quercetin, kaempferol and myricetin were significantly higher in brown than in white fibers and corresponding to the biosynthetic gene expression levels. CONCLUSIONS: Flavonoid structural gene expression and flavonoid metabolism are important in the development of pigmentation in brown cotton fibers.

  1. Emergent biosynthetic capacity in simple microbial communities.

    Directory of Open Access Journals (Sweden)

    Hsuan-Chao Chiu

    2014-07-01

    Full Text Available Microbes have an astonishing capacity to transform their environments. Yet, the metabolic capacity of a single species is limited and the vast majority of microorganisms form complex communities and join forces to exhibit capabilities far exceeding those achieved by any single species. Such enhanced metabolic capacities represent a promising route to many medical, environmental, and industrial applications and call for the development of a predictive, systems-level understanding of synergistic microbial capacity. Here we present a comprehensive computational framework, integrating high-quality metabolic models of multiple species, temporal dynamics, and flux variability analysis, to study the metabolic capacity and dynamics of simple two-species microbial ecosystems. We specifically focus on detecting emergent biosynthetic capacity--instances in which a community growing on some medium produces and secretes metabolites that are not secreted by any member species when growing in isolation on that same medium. Using this framework to model a large collection of two-species communities on multiple media, we demonstrate that emergent biosynthetic capacity is highly prevalent. We identify commonly observed emergent metabolites and metabolic reprogramming patterns, characterizing typical mechanisms of emergent capacity. We further find that emergent secretion tends to occur in two waves, the first as soon as the two organisms are introduced, and the second when the medium is depleted and nutrients become limited. Finally, aiming to identify global community determinants of emergent capacity, we find a marked association between the level of emergent biosynthetic capacity and the functional/phylogenetic distance between community members. Specifically, we demonstrate a "Goldilocks" principle, where high levels of emergent capacity are observed when the species comprising the community are functionally neither too close, nor too distant. Taken together

  2. Anthocyanin biosynthesis in fruit tree crops: Genes and their regulation

    African Journals Online (AJOL)

    The anthocyanin biosynthesis pathway is a little complex with branches responsible for the synthesis of a variety of metabolites. In fruit tree crops, during the past decade, many structural genes encoding enzymes in the anthocyanin biosynthetic pathway and various regulatory genes encoding transcription factors that ...

  3. A moth pheromone brewery: production of (Z)-11-hexadecenol by heterologous co-expression of two biosynthetic genes from a noctuid moth in a yeast cell factory.

    Science.gov (United States)

    Hagström, Åsa K; Wang, Hong-Lei; Liénard, Marjorie A; Lassance, Jean-Marc; Johansson, Tomas; Löfstedt, Christer

    2013-12-13

    Moths (Lepidoptera) are highly dependent on chemical communication to find a mate. Compared to conventional unselective insecticides, synthetic pheromones have successfully served to lure male moths as a specific and environmentally friendly way to control important pest species. However, the chemical synthesis and purification of the sex pheromone components in large amounts is a difficult and costly task. The repertoire of enzymes involved in moth pheromone biosynthesis in insecta can be seen as a library of specific catalysts that can be used to facilitate the synthesis of a particular chemical component. In this study, we present a novel approach to effectively aid in the preparation of semi-synthetic pheromone components using an engineered vector co-expressing two key biosynthetic enzymes in a simple yeast cell factory. We first identified and functionally characterized a ∆11 Fatty-Acyl Desaturase and a Fatty-Acyl Reductase from the Turnip moth, Agrotis segetum. The ∆11-desaturase produced predominantly Z11-16:acyl, a common pheromone component precursor, from the abundant yeast palmitic acid and the FAR transformed a series of saturated and unsaturated fatty acids into their corresponding alcohols which may serve as pheromone components in many moth species. Secondly, when we co-expressed the genes in the Brewer's yeast Saccharomyces cerevisiae, a set of long-chain fatty acids and alcohols that are not naturally occurring in yeast were produced from inherent yeast fatty acids, and the presence of (Z)-11-hexadecenol (Z11-16:OH), demonstrated that both heterologous enzymes were active in concert. A 100 ml batch yeast culture produced on average 19.5 μg Z11-16:OH. Finally, we demonstrated that oxidized extracts from the yeast cells containing (Z)-11-hexadecenal and other aldehyde pheromone compounds elicited specific electrophysiological activity from male antennae of the Tobacco budworm, Heliothis virescens, supporting the idea that genes from different

  4. On the biosynthetic origin of carminic acid

    DEFF Research Database (Denmark)

    Rasmussen, Silas A.; Kongstad, Kenneth T; Khorsand-Jamal, Paiman

    2018-01-01

    provides solid evidence of a polyketide, rather than a shikimate, origin of coccid pigments. Based on the newly identified compounds, we present a detailed biosynthetic scheme that accounts for the formation of carminic acid (CA) in D. coccus and all described coccid pigments which share a flavokermesic...... distribution suggests a common evolutionary origin for the trait in all coccid dye producing insect species....

  5. In silico identification of miRNAs and their target genes and analysis of gene co-expression network in saffron (Crocus sativus L.) stigma

    Science.gov (United States)

    Zinati, Zahra; Shamloo-Dashtpagerdi, Roohollah; Behpouri, Ali

    2016-01-01

    As an aromatic and colorful plant of substantive taste, saffron (Crocus sativus L.) owes such properties of matter to growing class of the secondary metabolites derived from the carotenoids, apocarotenoids. Regarding the critical role of microRNAs in secondary metabolic synthesis and the limited number of identified miRNAs in C. sativus, on the other hand, one may see the point how the characterization of miRNAs along with the corresponding target genes in C. sativus might expand our perspectives on the roles of miRNAs in carotenoid/apocarotenoid biosynthetic pathway. A computational analysis was used to identify miRNAs and their targets using EST (Expressed Sequence Tag) library from mature saffron stigmas. Then, a gene co- expression network was constructed to identify genes which are potentially involved in carotenoid/apocarotenoid biosynthetic pathways. EST analysis led to the identification of two putative miRNAs (miR414 and miR837-5p) along with the corresponding stem- looped precursors. To our knowledge, this is the first report on miR414 and miR837-5p in C. sativus. Co-expression network analysis indicated that miR414 and miR837-5p may play roles in C. sativus metabolic pathways and led to identification of candidate genes including six transcription factors and one protein kinase probably involved in carotenoid/apocarotenoid biosynthetic pathway. Presence of transcription factors, miRNAs and protein kinase in the network indicated multiple layers of regulation in saffron stigma. The candidate genes from this study may help unraveling regulatory networks underlying the carotenoid/apocarotenoid biosynthesis in saffron and designing metabolic engineering for enhanced secondary metabolites. PMID:28261627

  6. Regulation of the Omega-3 Fatty Acid Biosynthetic Pathway in Atlantic Salmon Hepatocytes.

    Directory of Open Access Journals (Sweden)

    Marte Avranden Kjær

    Full Text Available Limited availability of the n-3 fatty acids EPA and DHA have led to an interest in better understanding of the n-3 biosynthetic pathway and its regulation. The biosynthesis of alpha-linolenic acid to EPA and DHA involves several complex reaction steps including desaturation-, elongation- and peroxisomal beta-oxidation enzymes. The aims of the present experiments were to gain more knowledge on how this biosynthesis is regulated over time by different doses and fatty acid combinations. Hepatocytes isolated from salmon were incubated with various levels and combinations of oleic acid, EPA and DHA. Oleic acid led to a higher expression of the Δ6 fatty acid desaturase (fad genes Δ6fad_a, Δ6fad_b, Δ6fad_c and the elongase genes elovl2 compared with cells cultured in medium enriched with DHA. Further, the study showed rhythmic variations in expression over time. Levels were reached where a further increase in specific fatty acids given to the cells not stimulated the conversion further. The gene expression of Δ6fad_a_and Δ6fad_b responded similar to fatty acid treatment, suggesting a co-regulation of these genes, whereas Δ5fad and Δ6fad_c showed a different regulation pattern. EPA and DHA induced different gene expression patterns, especially of Δ6fad_a. Addition of radiolabelled alpha-linolenic acid to the hepatocytes confirmed a higher degree of elongation and desaturation in cells treated with oleic acid compared to cells treated with DHA. This study suggests a complex regulation of the conversion process of n-3 fatty acids. Several factors, such as that the various gene copies are differently regulated, the gene expression show rhythmic variations and gene expression only affected to a certain level, determines when you get the maximum conversion of the beneficial n-3 fatty acids.

  7. Identification of Secondary Metabolite Gene Clusters in the Pseudovibrio Genus Reveals Encouraging Biosynthetic Potential toward the Production of Novel Bioactive Compounds

    Directory of Open Access Journals (Sweden)

    Lynn M. Naughton

    2017-08-01

    Full Text Available Increased incidences of antimicrobial resistance and the emergence of pan-resistant ‘superbugs’ have provoked an extreme sense of urgency amongst researchers focusing on the discovery of potentially novel antimicrobial compounds. A strategic shift in focus from the terrestrial to the marine environment has resulted in the discovery of a wide variety of structurally and functionally diverse bioactive compounds from numerous marine sources, including sponges. Bacteria found in close association with sponges and other marine invertebrates have recently gained much attention as potential sources of many of these novel bioactive compounds. Members of the genus Pseudovibrio are one such group of organisms. In this study, we interrogate the genomes of 21 Pseudovibrio strains isolated from a variety of marine sources, for the presence, diversity and distribution of biosynthetic gene clusters (BGCs. We expand on results obtained from antiSMASH analysis to demonstrate the similarity between the Pseudovibrio-related BGCs and those characterized in other bacteria and corroborate our findings with phylogenetic analysis. We assess how domain organization of the most abundant type of BGCs present among the isolates (Non-ribosomal peptide synthetases and Polyketide synthases may influence the diversity of compounds produced by these organisms and highlight for the first time the potential for novel compound production from this genus of bacteria, using a genome guided approach.

  8. Evolutionary origins and functions of the carotenoid biosynthetic pathway in marine diatoms.

    Directory of Open Access Journals (Sweden)

    Sacha Coesel

    Full Text Available Carotenoids are produced by all photosynthetic organisms, where they play essential roles in light harvesting and photoprotection. The carotenoid biosynthetic pathway of diatoms is largely unstudied, but is of particular interest because these organisms have a very different evolutionary history with respect to the Plantae and are thought to be derived from an ancient secondary endosymbiosis between heterotrophic and autotrophic eukaryotes. Furthermore, diatoms have an additional xanthophyll-based cycle for dissipating excess light energy with respect to green algae and higher plants. To explore the origins and functions of the carotenoid pathway in diatoms we searched for genes encoding pathway components in the recently completed genome sequences of two marine diatoms. Consistent with the supplemental xanthophyll cycle in diatoms, we found more copies of the genes encoding violaxanthin de-epoxidase (VDE and zeaxanthin epoxidase (ZEP enzymes compared with other photosynthetic eukaryotes. However, the similarity of these enzymes with those of higher plants indicates that they had very probably diversified before the secondary endosymbiosis had occurred, implying that VDE and ZEP represent early eukaryotic innovations in the Plantae. Consequently, the diatom chromist lineage likely obtained all paralogues of ZEP and VDE genes during the process of secondary endosymbiosis by gene transfer from the nucleus of the algal endosymbiont to the host nucleus. Furthermore, the presence of a ZEP gene in Tetrahymena thermophila provides the first evidence for a secondary plastid gene encoded in a heterotrophic ciliate, providing support for the chromalveolate hypothesis. Protein domain structures and expression analyses in the pennate diatom Phaeodactylum tricornutum indicate diverse roles for the different ZEP and VDE isoforms and demonstrate that they are differentially regulated by light. These studies therefore reveal the ancient origins of several

  9. Evolutionary origins and functions of the carotenoid biosynthetic pathway in marine diatoms.

    Science.gov (United States)

    Coesel, Sacha; Oborník, Miroslav; Varela, Joao; Falciatore, Angela; Bowler, Chris

    2008-08-06

    Carotenoids are produced by all photosynthetic organisms, where they play essential roles in light harvesting and photoprotection. The carotenoid biosynthetic pathway of diatoms is largely unstudied, but is of particular interest because these organisms have a very different evolutionary history with respect to the Plantae and are thought to be derived from an ancient secondary endosymbiosis between heterotrophic and autotrophic eukaryotes. Furthermore, diatoms have an additional xanthophyll-based cycle for dissipating excess light energy with respect to green algae and higher plants. To explore the origins and functions of the carotenoid pathway in diatoms we searched for genes encoding pathway components in the recently completed genome sequences of two marine diatoms. Consistent with the supplemental xanthophyll cycle in diatoms, we found more copies of the genes encoding violaxanthin de-epoxidase (VDE) and zeaxanthin epoxidase (ZEP) enzymes compared with other photosynthetic eukaryotes. However, the similarity of these enzymes with those of higher plants indicates that they had very probably diversified before the secondary endosymbiosis had occurred, implying that VDE and ZEP represent early eukaryotic innovations in the Plantae. Consequently, the diatom chromist lineage likely obtained all paralogues of ZEP and VDE genes during the process of secondary endosymbiosis by gene transfer from the nucleus of the algal endosymbiont to the host nucleus. Furthermore, the presence of a ZEP gene in Tetrahymena thermophila provides the first evidence for a secondary plastid gene encoded in a heterotrophic ciliate, providing support for the chromalveolate hypothesis. Protein domain structures and expression analyses in the pennate diatom Phaeodactylum tricornutum indicate diverse roles for the different ZEP and VDE isoforms and demonstrate that they are differentially regulated by light. These studies therefore reveal the ancient origins of several components of the

  10. Fabrication of biosynthetic vascular prostheses by 193-nm excimer laser radiation

    Science.gov (United States)

    Husinsky, Wolfgang; Csek, Ch.; Bartel, A.; Grabenwoeger, M.; Fitzal, F.; Wolner, Ernst

    1998-05-01

    This study was undertaken to investigate the feasibility of transmural capillary ingrowth into the inner surface of biosynthetic vascular prostheses (OmniflowTM) through perforations created by an excimer-laser, thus inducing an endothelial cell coverage. The biosynthetic vascular prostheses (10 cm length, 6 mm (phi) ) were perforated with an excimer laser ((phi) of the holes 50 - 100 micrometer, distance 4 mm) and implanted into the carotid arteries of 8 sheep. The laser tissue interaction process of 193 nm radiation ensures minimal thermal damage to the prostheses. They were compared to untreated OmniflowTM prostheses implanted at the contralateral side. Three months after implantation the prostheses were explanted and evaluated by gross morphology, histological examination and scanning electron microscopy. Scanning electron microscopy showed endothelial cells in the midgraft portion of all perforated prostheses, whereas collagen fibers, fibrin meshwork and activated platelets formed the inner layer in 6 out of 8 untreated OmniflowTM prostheses. It can be concluded, that spontaneous endothelialization of biosynthetic vascular prostheses can be achieved by transmural capillary ingrowth through perforations in the wall of the prostheses in an experimental sheep model.

  11. What is the evidence for the use of biologic or biosynthetic meshes in abdominal wall reconstruction?

    Science.gov (United States)

    Köckerling, F; Alam, N N; Antoniou, S A; Daniels, I R; Famiglietti, F; Fortelny, R H; Heiss, M M; Kallinowski, F; Kyle-Leinhase, I; Mayer, F; Miserez, M; Montgomery, A; Morales-Conde, S; Muysoms, F; Narang, S K; Petter-Puchner, A; Reinpold, W; Scheuerlein, H; Smietanski, M; Stechemesser, B; Strey, C; Woeste, G; Smart, N J

    2018-04-01

    Although many surgeons have adopted the use of biologic and biosynthetic meshes in complex abdominal wall hernia repair, others have questioned the use of these products. Criticism is addressed in several review articles on the poor standard of studies reporting on the use of biologic meshes for different abdominal wall repairs. The aim of this consensus review is to conduct an evidence-based analysis of the efficacy of biologic and biosynthetic meshes in predefined clinical situations. A European working group, "BioMesh Study Group", composed of invited surgeons with a special interest in surgical meshes, formulated key questions, and forwarded them for processing in subgroups. In January 2016, a workshop was held in Berlin where the findings were presented, discussed, and voted on for consensus. Findings were set out in writing by the subgroups followed by consensus being reached. For the review, 114 studies and background analyses were used. The cumulative data regarding biologic mesh under contaminated conditions do not support the claim that it is better than synthetic mesh. Biologic mesh use should be avoided when bridging is needed. In inguinal hernia repair biologic and biosynthetic meshes do not have a clear advantage over the synthetic meshes. For prevention of incisional or parastomal hernias, there is no evidence to support the use of biologic/biosynthetic meshes. In complex abdominal wall hernia repairs (incarcerated hernia, parastomal hernia, infected mesh, open abdomen, enterocutaneous fistula, and component separation technique), biologic and biosynthetic meshes do not provide a superior alternative to synthetic meshes. The routine use of biologic and biosynthetic meshes cannot be recommended.

  12. Aflatoxin B1 inhibition in Aspergillus flavus by Aspergillus niger through down-regulating expression of major biosynthetic genes and AFB1 degradation by atoxigenic A. flavus.

    Science.gov (United States)

    Xing, Fuguo; Wang, Limin; Liu, Xiao; Selvaraj, Jonathan Nimal; Wang, Yan; Zhao, Yueju; Liu, Yang

    2017-09-01

    Twenty Aspergillus niger strains were isolated from peanuts and 14 strains were able to completely inhibit AFB 1 production with co-cultivation. By using a Spin-X centrifuge system, it was confirmed that there are some soluble signal molecules or antibiotics involved in the inhibition by A. niger, although they are absent during the initial 24h of A. flavus growth when it is sensitive to inhibition. In A. flavus, 19 of 20 aflatoxin biosynthetic genes were down-regulated by A. niger. Importantly, the expression of aflS was significantly down-regulated, resulting in a reduction of AflS/AflR ratio. The results suggest that A. niger could directly inhibit AFB 1 biosynthesis through reducing the abundance of aflS to aflR mRNAs. Interestingly, atoxigenic A. flavus JZ2 and GZ15 effectively degrade AFB 1 . Two new metabolites were identified and the key toxic lactone and furofuran rings both were destroyed and hydrogenated, meaning that lactonase and reductase might be involved in the degradation process. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Comparative transcriptomic analyses of differentially expressed genes in transgenic melatonin biosynthesis ovine HIOMT gene in switchgrass

    Directory of Open Access Journals (Sweden)

    Shan Yuan

    2016-11-01

    Full Text Available Melatonin serves pleiotropic functions in prompting plant growth and resistance to various stresses. The accurate biosynthetic pathway of melatonin remains elusive in plant species, while the N-acetyltransferase and O-methyltransferase were considered to be the last two key enzymes during its biosynthesis. To investigate the biosynthesis and metabolic pathway of melatonin in plants, the RNA-seq profile of overexpression of the ovine HIOMT was analyzed and compared with the previous transcriptome of transgenic oAANAT gene in switchgrass, a model plant for cellulosic ethanol production. A total of 946, 405 and 807 differentially expressed unigenes were observed in AANAT vs. control, HIOMT vs. control, and AANAT vs. HIOMT, respectively. The significantly upregulated (F-box/kelch-repeat protein, zinc finger BED domain-containing protein-3 genes were consistent with enhanced phenotypes of shoot, stem and root growth in transgenic oHIOMT switchgrass. Early flowering in overexpression of oHIOMT switchgrass involved in the regulation of flowering-time genes (APETALA2. Several stress resistant related genes (SPX domain-containing membrane protein, copper transporter 1, late blight resistance protein homolog R1A-6 OS etc. were specifically and significantly upregulated in transgenic oHIOMT only, while metabolism-related genes (phenylalanine-4-hydroxylase, tyrosine decarboxylase 1, protein disulfide-isomerase and galactinol synthase 2 etc. were significantly upregulated in transgenic oAANAT only. These results provide new sights into the biosynthetic and physiological functional networks of melatonin in plants.

  14. Directed natural product biosynthesis gene cluster capture and expression in the model bacterium Bacillus subtilis

    KAUST Repository

    Li, Yongxin

    2015-03-24

    Bacilli are ubiquitous low G+C environmental Gram-positive bacteria that produce a wide assortment of specialized small molecules. Although their natural product biosynthetic potential is high, robust molecular tools to support the heterologous expression of large biosynthetic gene clusters in Bacillus hosts are rare. Herein we adapt transformation-associated recombination (TAR) in yeast to design a single genomic capture and expression vector for antibiotic production in Bacillus subtilis. After validating this direct cloning plug-and-playa approach with surfactin, we genetically interrogated amicoumacin biosynthetic gene cluster from the marine isolate Bacillus subtilis 1779. Its heterologous expression allowed us to explore an unusual maturation process involving the N-acyl-asparagine pro-drug intermediates preamicoumacins, which are hydrolyzed by the asparagine-specific peptidase into the active component amicoumacin A. This work represents the first direct cloning based heterologous expression of natural products in the model organism B. subtilis and paves the way to the development of future genome mining efforts in this genus.

  15. Directed natural product biosynthesis gene cluster capture and expression in the model bacterium Bacillus subtilis

    Science.gov (United States)

    Li, Yongxin; Li, Zhongrui; Yamanaka, Kazuya; Xu, Ying; Zhang, Weipeng; Vlamakis, Hera; Kolter, Roberto; Moore, Bradley S.; Qian, Pei-Yuan

    2015-03-01

    Bacilli are ubiquitous low G+C environmental Gram-positive bacteria that produce a wide assortment of specialized small molecules. Although their natural product biosynthetic potential is high, robust molecular tools to support the heterologous expression of large biosynthetic gene clusters in Bacillus hosts are rare. Herein we adapt transformation-associated recombination (TAR) in yeast to design a single genomic capture and expression vector for antibiotic production in Bacillus subtilis. After validating this direct cloning ``plug-and-play'' approach with surfactin, we genetically interrogated amicoumacin biosynthetic gene cluster from the marine isolate Bacillus subtilis 1779. Its heterologous expression allowed us to explore an unusual maturation process involving the N-acyl-asparagine pro-drug intermediates preamicoumacins, which are hydrolyzed by the asparagine-specific peptidase into the active component amicoumacin A. This work represents the first direct cloning based heterologous expression of natural products in the model organism B. subtilis and paves the way to the development of future genome mining efforts in this genus.

  16. Bacterial natural product biosynthetic domain composition in soil correlates with changes in latitude on a continent-wide scale.

    Science.gov (United States)

    Lemetre, Christophe; Maniko, Jeffrey; Charlop-Powers, Zachary; Sparrow, Ben; Lowe, Andrew J; Brady, Sean F

    2017-10-31

    Although bacterial bioactive metabolites have been one of the most prolific sources of lead structures for the development of small-molecule therapeutics, very little is known about the environmental factors associated with changes in secondary metabolism across natural environments. Large-scale sequencing of environmental microbiomes has the potential to shed light on the richness of bacterial biosynthetic diversity hidden in the environment, how it varies from one environment to the next, and what environmental factors correlate with changes in biosynthetic diversity. In this study, the sequencing of PCR amplicons generated using primers targeting either ketosynthase domains from polyketide biosynthesis or adenylation domains from nonribosomal peptide biosynthesis was used to assess biosynthetic domain composition and richness in soils collected across the Australian continent. Using environmental variables collected at each soil site, we looked for environmental factors that correlated with either high overall domain richness or changes in the domain composition. Among the environmental variables we measured, changes in biosynthetic domain composition correlate most closely with changes in latitude and to a lesser extent changes in pH. Although it is unclear at this time the exact mix of factors that may drive the relationship between biosynthetic domain composition and latitude, from a practical perspective the identification of a latitudinal basis for differences in soil metagenome biosynthetic domain compositions should help guide future natural product discovery efforts. Published under the PNAS license.

  17. Genome sequence of Thermofilum pendens reveals an exceptional loss of biosynthetic pathways without genome reduction

    Energy Technology Data Exchange (ETDEWEB)

    Kyrpides, Nikos; Anderson, Iain; Rodriguez, Jason; Susanti, Dwi; Porat, Iris; Reich, Claudia; Ulrich, Luke E.; Elkins, James G.; Mavromatis, Kostas; Lykidis, Athanasios; Kim, Edwin; Thompson, Linda S.; Nolan, Matt; Land, Miriam; Copeland, Alex; Lapidus, Alla; Lucas, Susan; Detter, Chris; Zhulin, Igor B.; Olsen, Gary J.; Whitman, William; Mukhopadhyay, Biswarup; Bristow, James; Kyrpides, Nikos

    2008-01-01

    We report the complete genome of Thermofilum pendens, a deep-branching, hyperthermophilic member of the order Thermoproteales within the archaeal kingdom Crenarchaeota. T. pendens is a sulfur-dependent, anaerobic heterotroph isolated from a solfatara in Iceland. It is an extracellular commensal, requiring an extract of Thermoproteus tenax for growth, and the genome sequence reveals that biosynthetic pathways for purines, most amino acids, and most cofactors are absent. In fact T. pendens has fewer biosynthetic enzymes than obligate intracellular parasites, although it does not display other features common among obligate parasites and thus does not appear to be in the process of becoming a parasite. It appears that T. pendens has adapted to life in an environment rich in nutrients. T. pendens was known to utilize peptides as an energy source, but the genome reveals substantial ability to grow on carbohydrates. T. pendens is the first crenarchaeote and only the second archaeon found to have a transporter of the phosphotransferase system. In addition to fermentation, T. pendens may gain energy from sulfur reduction with hydrogen and formate as electron donors. It may also be capable of sulfur-independent growth on formate with formate hydrogenlyase. Additional novel features are the presence of a monomethylamine:corrinoid methyltransferase, the first time this enzyme has been found outside of Methanosarcinales, and a presenilin-related protein. Predicted highly expressed proteins do not include housekeeping genes, and instead include ABC transporters for carbohydrates and peptides, and CRISPR-associated proteins.

  18. Markerless gene knockout and integration to express heterologous biosynthetic gene clusters in Pseudomonas putida

    DEFF Research Database (Denmark)

    Choi, Kyeong Rok; Cho, Jae Sung; Cho, In Jin

    2018-01-01

    Pseudomonas putida has gained much interest among metabolic engineers as a workhorse for producing valuable natural products. While a few gene knockout tools for P. putida have been reported, integration of heterologous genes into the chromosome of P. putida, an essential strategy to develop stable...... plasmid curing systems, generating final strains free of antibiotic markers and plasmids. This markerless recombineering system for efficient gene knockout and integration will expedite metabolic engineering of P. putida, a bacterial host strain of increasing academic and industrial interest....

  19. De novo transcriptome sequencing and digital gene expression analysis predict biosynthetic pathway of rhynchophylline and isorhynchophylline from Uncaria rhynchophylla, a non-model plant with potent anti-alzheimer's properties.

    Science.gov (United States)

    Guo, Qianqian; Ma, Xiaojun; Wei, Shugen; Qiu, Deyou; Wilson, Iain W; Wu, Peng; Tang, Qi; Liu, Lijun; Dong, Shoukun; Zu, Wei

    2014-08-12

    The major medicinal alkaloids isolated from Uncaria rhynchophylla (gouteng in chinese) capsules are rhynchophylline (RIN) and isorhynchophylline (IRN). Extracts containing these terpene indole alkaloids (TIAs) can inhibit the formation and destabilize preformed fibrils of amyloid β protein (a pathological marker of Alzheimer's disease), and have been shown to improve the cognitive function of mice with Alzheimer-like symptoms. The biosynthetic pathways of RIN and IRN are largely unknown. In this study, RNA-sequencing of pooled Uncaria capsules RNA samples taken at three developmental stages that accumulate different amount of RIN and IRN was performed. More than 50 million high-quality reads from a cDNA library were generated and de novo assembled. Sequences for all of the known enzymes involved in TIAs synthesis were identified. Additionally, 193 cytochrome P450 (CYP450), 280 methyltransferase and 144 isomerase genes were identified, that are potential candidates for enzymes involved in RIN and IRN synthesis. Digital gene expression profile (DGE) analysis was performed on the three capsule developmental stages, and based on genes possessing expression profiles consistent with RIN and IRN levels; four CYP450s, three methyltransferases and three isomerases were identified as the candidates most likely to be involved in the later steps of RIN and IRN biosynthesis. A combination of de novo transcriptome assembly and DGE analysis was shown to be a powerful method for identifying genes encoding enzymes potentially involved in the biosynthesis of important secondary metabolites in a non-model plant. The transcriptome data from this study provides an important resource for understanding the formation of major bioactive constituents in the capsule extract from Uncaria, and provides information that may aid in metabolic engineering to increase yields of these important alkaloids.

  20. Variation in sequence and location of the fumonisin mycotoxin niosynthetic gene cluster in Fusarium

    NARCIS (Netherlands)

    Proctor, R.H.; Hove, van F.; Susca, A.; Stea, A.; Busman, M.; Lee, van der T.A.J.; Waalwijk, C.; Moretti, A.

    2010-01-01

    In Fusarium, the ability to produce fumonisins is governed by a 17-gene fumonisin biosynthetic gene (FUM) cluster. Here, we examined the cluster in F. oxysporum strain O-1890 and nine other species selected to represent a wide range of the genetic diversity within the GFSC.

  1. Transcriptomic analysis of Siberian ginseng (Eleutherococcus senticosus) to discover genes involved in saponin biosynthesis.

    Science.gov (United States)

    Hwang, Hwan-Su; Lee, Hyoshin; Choi, Yong Eui

    2015-03-14

    Eleutherococcus senticosus, Siberian ginseng, is a highly valued woody medicinal plant belonging to the family Araliaceae. E. senticosus produces a rich variety of saponins such as oleanane-type, noroleanane-type, 29-hydroxyoleanan-type, and lupane-type saponins. Genomic or transcriptomic approaches have not been used to investigate the saponin biosynthetic pathway in this plant. In this study, de novo sequencing was performed to select candidate genes involved in the saponin biosynthetic pathway. A half-plate 454 pyrosequencing run produced 627,923 high-quality reads with an average sequence length of 422 bases. De novo assembly generated 72,811 unique sequences, including 15,217 contigs and 57,594 singletons. Approximately 48,300 (66.3%) unique sequences were annotated using BLAST similarity searches. All of the mevalonate pathway genes for saponin biosynthesis starting from acetyl-CoA were isolated. Moreover, 206 reads of cytochrome P450 (CYP) and 145 reads of uridine diphosphate glycosyltransferase (UGT) sequences were isolated. Based on methyl jasmonate (MeJA) treatment and real-time PCR (qPCR) analysis, 3 CYPs and 3 UGTs were finally selected as candidate genes involved in the saponin biosynthetic pathway. The identified sequences associated with saponin biosynthesis will facilitate the study of the functional genomics of saponin biosynthesis and genetic engineering of E. senticosus.

  2. Plasmid-encoded biosynthetic genes alleviate metabolic disadvantages while increasing glucose conversion to shikimate in an engineered Escherichia coli strain.

    Science.gov (United States)

    Rodriguez, Alberto; Martínez, Juan A; Millard, Pierre; Gosset, Guillermo; Portais, Jean-Charles; Létisse, Fabien; Bolivar, Francisco

    2017-06-01

    Metabolic engineering strategies applied over the last two decades to produce shikimate (SA) in Escherichia coli have resulted in a battery of strains bearing many expression systems. However, the effects that these systems have on the host physiology and how they impact the production of SA are still not well understood. In this work we utilized an engineered E. coli strain to determine the consequences of carrying a vector that promotes SA production from glucose with a high-yield but that is also expected to impose a significant cellular burden. Kinetic comparisons in fermentors showed that instead of exerting a negative effect, the sole presence of the plasmid increased glucose consumption without diminishing the growth rate. By constitutively expressing a biosynthetic operon from this vector, the more active glycolytic metabolism was exploited to redirect intermediates toward the production of SA, which further increased the glucose consumption rate and avoided excess acetate production. Fluxomics and metabolomics experiments revealed a global remodeling of the carbon and energy metabolism in the production strain, where the increased SA production reduced the carbon available for oxidative and fermentative pathways. Moreover, the results showed that the production of SA relies on a specific setup of the pentose phosphate pathway, where both its oxidative and non-oxidative branches are strongly activated to supply erythrose-4-phosphate and balance the NADPH requirements. This work improves our understanding of the metabolic reorganization observed in E. coli in response to the plasmid-based expression of the SA biosynthetic pathway. Biotechnol. Bioeng. 2017;114: 1319-1330. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Functions of some capsular polysaccharide biosynthetic genes in Klebsiella pneumoniae NTUH K-2044.

    Directory of Open Access Journals (Sweden)

    Jin-Yuan Ho

    Full Text Available The growing number of Klebsiella pneumoniae infections, commonly acquired in hospitals, has drawn great concern. It has been shown that the K1 and K2 capsular serotypes are the most detrimental strains, particularly to those with diabetes. The K1 cps (capsular polysaccharide locus in the NTUH-2044 strain of the pyogenic liver abscess (PLA K. pneumoniae has been identified recently, but little is known about the functions of the genes therein. Here we report characterization of a group of cps genes and their roles in the pathogenesis of K1 K. pneumoniae. By sequential gene deletion, the cps gene cluster was first re-delimited between genes galF and ugd, which serve as up- and down-stream ends, respectively. Eight gene products were characterized in vitro and in vivo to be involved in the syntheses of UDP-glucose, UDP-glucuronic acid and GDP-fucose building units. Twelve genes were identified as virulence factors based on the observation that their deletion mutants became avirulent or lost K1 antigenicity. Furthermore, deletion of kp3706, kp3709 or kp3712 (ΔwcaI, ΔwcaG or Δatf, respectively, which are all involved in fucose biosynthesis, led to a broad range of transcriptional suppression for 52 upstream genes. The genes suppressed include those coding for unknown regulatory membrane proteins and six multidrug efflux system proteins, as well as proteins required for the K1 CPS biosynthesis. In support of the suppression of multidrug efflux genes, we showed that these three mutants became more sensitive to antibiotics. Taken together, the results suggest that kp3706, kp3709 or kp3712 genes are strongly related to the pathogenesis of K. pneumoniae K1.

  4. Antimicrobial biosynthetic potential and genetic diversity of endophytic actinomycetes associated with medicinal plants.

    Science.gov (United States)

    Gohain, Anwesha; Gogoi, Animesh; Debnath, Rajal; Yadav, Archana; Singh, Bhim P; Gupta, Vijai K; Sharma, Rajeev; Saikia, Ratul

    2015-10-01

    Endophytic actinomycetes are one of the primary groups that share symbiotic relationships with medicinal plants and are key reservoir of biologically active compounds. In this study, six selective medicinal plants were targeted for the first time for endophytic actinomycetes isolation from Gibbon Wild Life Sanctuary, Assam, India, during winter and summer and 76 isolates were obtained. The isolates were found to be prevalent in roots followed by stem and leaves. 16S rRNA gene sequence analysis revealed 16 genera, including rare genera, Verrucosispora, Isoptericola and Kytococcus, which have never been previously reported as endophytic. The genus Streptomyces (66%) was dominant in both seasons. Shannon's diversity index showed that Azadirachta indica (1.49), Rauwolfia serpentina (1.43) and Emblica officinalis (1.24) were relatively good habitat for endophytic actinomycetes. Antimicrobial strains showed prevalence of polyketide synthase (PKS) type-II (85%) followed by PKS type-I (14%) encoded in the genomes. Expression studies showed 12-fold upregulation of PKSII gene in seventh day of incubation for Streptomyces antibioticus (EAAG90). Our results emphasize that the actinomycetes assemblages within plant tissue exhibited biosynthetic systems encoding for important biologically active compounds. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. A simple biosynthetic pathway for large product generation from small substrate amounts

    Science.gov (United States)

    Djordjevic, Marko; Djordjevic, Magdalena

    2012-10-01

    A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways.

  6. A simple biosynthetic pathway for large product generation from small substrate amounts

    Energy Technology Data Exchange (ETDEWEB)

    Djordjevic, Marko [Institute of Physiology and Biochemistry, Faculty of Biology, University of Belgrade (Serbia); Djordjevic, Magdalena [Institute of Physics Belgrade, University of Belgrade (Serbia)

    2012-10-01

    A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways. (paper)

  7. A simple biosynthetic pathway for large product generation from small substrate amounts

    International Nuclear Information System (INIS)

    Djordjevic, Marko; Djordjevic, Magdalena

    2012-01-01

    A recently emerging discipline of synthetic biology has the aim of constructing new biosynthetic pathways with useful biological functions. A major application of these pathways is generating a large amount of the desired product. However, toxicity due to the possible presence of toxic precursors is one of the main problems for such production. We consider here the problem of generating a large amount of product from a potentially toxic substrate. To address this, we propose a simple biosynthetic pathway, which can be induced in order to produce a large number of the product molecules, by keeping the substrate amount at low levels. Surprisingly, we show that the large product generation crucially depends on fast non-specific degradation of the substrate molecules. We derive an optimal induction strategy, which allows as much as three orders of magnitude increase in the product amount through biologically realistic parameter values. We point to a recently discovered bacterial immune system (CRISPR/Cas in E. coli) as a putative example of the pathway analysed here. We also argue that the scheme proposed here can be used not only as a stand-alone pathway, but also as a strategy to produce a large amount of the desired molecules with small perturbations of endogenous biosynthetic pathways. (paper)

  8. Effects of polyamines and polyamine biosynthetic inhibitors on mitotic activity of Allium cepa root tips.

    Science.gov (United States)

    Unal, Meral; Palavan-Unsal, Narcin; Tufekci, M A

    2008-03-01

    The genotoxic and cytotoxic effects of exogenous polyamines (PAs), putrescine (Put), spermidine (Spd), spermine (Spm) and PA biosynthetic inhibitors, alpha-difluoromethylornithine (DFMO), cyclohexilamine (CHA), methylglioxal bis-(guanylhydrazone) (MGBG) were investigated in the root meristems of Allium cepa L. The reduction of mitotic index and the induction of chromosomal aberrations such as bridges, stickiness, c-mitotic anaphases, micronuclei, endoredupliction by PAs and PA biosynthetic inhibitors were observed and these were used as evidence of genotoxicity and cytotoxicity.

  9. cDNA cloning and expression of anthocyanin biosynthetic genes in ...

    African Journals Online (AJOL)

    GRACE

    2006-05-16

    May 16, 2006 ... that influence anthocyanin pigments have been isolated from Solanaceae. A few genes of anthocyanin ... Long, 1955), and the purple anthocyanin pigments are primarily derived from the related compound ..... anthocyanin production in tuber skins. this result was similar with carrot (daucus carota l) cell ...

  10. An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae.

    Science.gov (United States)

    Lin-Wang, Kui; Bolitho, Karen; Grafton, Karryn; Kortstee, Anne; Karunairetnam, Sakuntala; McGhie, Tony K; Espley, Richard V; Hellens, Roger P; Allan, Andrew C

    2010-03-21

    The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the gene determining fruit flesh and foliage anthocyanin has been termed MYB10. In order to further understand tissue-specific anthocyanin regulation we have isolated orthologous MYB genes from all the commercially important rosaceous species. We use gene specific primers to show that the three MYB activators of apple anthocyanin (MYB10/MYB1/MYBA) are likely alleles of each other. MYB transcription factors, with high sequence identity to the apple gene were isolated from across the rosaceous family (e.g. apples, pears, plums, cherries, peaches, raspberries, rose, strawberry). Key identifying amino acid residues were found in both the DNA-binding and C-terminal domains of these MYBs. The expression of these MYB10 genes correlates with fruit and flower anthocyanin levels. Their function was tested in tobacco and strawberry. In tobacco, these MYBs were shown to induce the anthocyanin pathway when co-expressed with bHLHs, while over-expression of strawberry and apple genes in the crop of origin elevates anthocyanins. This family-wide study of rosaceous R2R3 MYBs provides insight into the evolution of this plant trait. It has implications for the development of new coloured fruit and flowers, as well as aiding the understanding of temporal-spatial colour change.

  11. An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae

    Directory of Open Access Journals (Sweden)

    McGhie Tony K

    2010-03-01

    Full Text Available Abstract Background The control of plant anthocyanin accumulation is via transcriptional regulation of the genes encoding the biosynthetic enzymes. A key activator appears to be an R2R3 MYB transcription factor. In apple fruit, skin anthocyanin levels are controlled by a gene called MYBA or MYB1, while the gene determining fruit flesh and foliage anthocyanin has been termed MYB10. In order to further understand tissue-specific anthocyanin regulation we have isolated orthologous MYB genes from all the commercially important rosaceous species. Results We use gene specific primers to show that the three MYB activators of apple anthocyanin (MYB10/MYB1/MYBA are likely alleles of each other. MYB transcription factors, with high sequence identity to the apple gene were isolated from across the rosaceous family (e.g. apples, pears, plums, cherries, peaches, raspberries, rose, strawberry. Key identifying amino acid residues were found in both the DNA-binding and C-terminal domains of these MYBs. The expression of these MYB10 genes correlates with fruit and flower anthocyanin levels. Their function was tested in tobacco and strawberry. In tobacco, these MYBs were shown to induce the anthocyanin pathway when co-expressed with bHLHs, while over-expression of strawberry and apple genes in the crop of origin elevates anthocyanins. Conclusions This family-wide study of rosaceous R2R3 MYBs provides insight into the evolution of this plant trait. It has implications for the development of new coloured fruit and flowers, as well as aiding the understanding of temporal-spatial colour change.

  12. SCREENING OF ANTIMICROBIAL ACTIVITY AND GENES CODING POLYKETIDE SYNTHETASE AND NONRIBOSOMAL PEPTIDE SYNTHETASE OF ACTINOMYCETE ISOLATES

    Directory of Open Access Journals (Sweden)

    Silvia Kovácsová

    2013-12-01

    Full Text Available The aim of this study was to observe antimicrobial activity using agar plate diffusion method and screening genes coding polyketide synthetase (PKS-I and nonribosomal peptide synthetase (NRPS from actinomycetes. A total of 105 actinomycete strains were isolated from arable soil. Antimicrobial activity was demonstrated at 54 strains against at least 1 of total 12 indicator organisms. Antifungal properties were recorded more often than antibacterial properties. The presence of PKS-I and NRPS genes were founded at 61 of total 105 strains. The number of strains with mentioned biosynthetic enzyme gene fragments matching the anticipated length were 19 (18% and 50 (47% respectively. Overall, five actinomycete strains carried all the biosynthetical genes, yet no antimicrobial activity was found against any of tested pathogens. On the other hand, twenty-one strains showed antimicrobial activity even though we were not able to amplify any of the PKS or NRPS genes from them. Combination of the two methods showed broad-spectrum antimicrobial activity of actinomycetes isolated from arable soil, which indicate that actinomycetes are valuable reservoirs of novel bioactive compounds.

  13. Genomics-Based Discovery of Plant Genes for Synthetic Biology of Terpenoid Fragrances: A Case Study in Sandalwood oil Biosynthesis.

    Science.gov (United States)

    Celedon, J M; Bohlmann, J

    2016-01-01

    Terpenoid fragrances are powerful mediators of ecological interactions in nature and have a long history of traditional and modern industrial applications. Plants produce a great diversity of fragrant terpenoid metabolites, which make them a superb source of biosynthetic genes and enzymes. Advances in fragrance gene discovery have enabled new approaches in synthetic biology of high-value speciality molecules toward applications in the fragrance and flavor, food and beverage, cosmetics, and other industries. Rapid developments in transcriptome and genome sequencing of nonmodel plant species have accelerated the discovery of fragrance biosynthetic pathways. In parallel, advances in metabolic engineering of microbial and plant systems have established platforms for synthetic biology applications of some of the thousands of plant genes that underlie fragrance diversity. While many fragrance molecules (eg, simple monoterpenes) are abundant in readily renewable plant materials, some highly valuable fragrant terpenoids (eg, santalols, ambroxides) are rare in nature and interesting targets for synthetic biology. As a representative example for genomics/transcriptomics enabled gene and enzyme discovery, we describe a strategy used successfully for elucidation of a complete fragrance biosynthetic pathway in sandalwood (Santalum album) and its reconstruction in yeast (Saccharomyces cerevisiae). We address questions related to the discovery of specific genes within large gene families and recovery of rare gene transcripts that are selectively expressed in recalcitrant tissues. To substantiate the validity of the approaches, we describe the combination of methods used in the gene and enzyme discovery of a cytochrome P450 in the fragrant heartwood of tropical sandalwood, responsible for the fragrance defining, final step in the biosynthesis of (Z)-santalols. © 2016 Elsevier Inc. All rights reserved.

  14. Identification of a trichothecene gene cluster and description of the harzianum A biosynthesis pathway in the fungus Trichoderma arundinaceum

    Science.gov (United States)

    Trichothecenes are sesquiterpenes that act like mycotoxins. Their biosynthesis has been mainly studied in the fungal genera Fusarium, where most of the biosynthetic genes (tri) are grouped in a cluster regulated by ambient conditions and regulatory genes. Unexpectedly, few studies are available abou...

  15. Functional genomics reveals increases in cholesterol biosynthetic genes and highly unsaturated fatty acid biosynthesis after dietary substitution of fish oil with vegetable oils in Atlantic salmon (Salmo salar

    Directory of Open Access Journals (Sweden)

    Bron James E

    2008-06-01

    Full Text Available Abstract Background There is an increasing drive to replace fish oil (FO in finfish aquaculture diets with vegetable oils (VO, driven by the short supply of FO derived from wild fish stocks. However, little is known of the consequences for fish health after such substitution. The effect of dietary VO on hepatic gene expression, lipid composition and growth was determined in Atlantic salmon (Salmo salar, using a combination of cDNA microarray, lipid, and biochemical analysis. FO was replaced with VO, added to diets as rapeseed (RO, soybean (SO or linseed (LO oils. Results Dietary VO had no major effect on growth of the fish, but increased the whole fish protein contents and tended to decrease whole fish lipid content, thus increasing the protein:lipid ratio. Expression levels of genes of the highly unsaturated fatty acid (HUFA and cholesterol biosynthetic pathways were increased in all vegetable oil diets as was SREBP2, a master transcriptional regulator of these pathways. Other genes whose expression was increased by feeding VO included those of NADPH generation, lipid transport, peroxisomal fatty acid oxidation, a marker of intracellular lipid accumulation, and protein and RNA processing. Consistent with these results, HUFA biosynthesis, hepatic β-oxidation activity and enzymic NADPH production were changed by VO, and there was a trend for increased hepatic lipid in LO and SO diets. Tissue cholesterol levels in VO fed fish were the same as animals fed FO, whereas fatty acid composition of the tissues largely reflected those of the diets and was marked by enrichment of 18 carbon fatty acids and reductions in 20 and 22 carbon HUFA. Conclusion This combined gene expression, compositional and metabolic study demonstrates that major lipid metabolic effects occur after replacing FO with VO in salmon diets. These effects are most likely mediated by SREBP2, which responds to reductions in dietary cholesterol. These changes are sufficient to maintain

  16. Metabolic engineering of the omega-3 long chain polyunsaturated fatty acid biosynthetic pathway into transgenic plants.

    Science.gov (United States)

    Ruiz-López, Noemi; Sayanova, Olga; Napier, Johnathan A; Haslam, Richard P

    2012-04-01

    Omega-3 (ω-3) very long chain polyunsaturated fatty acids (VLC-PUFAs) such as eicosapentaenoic acid (EPA; 20:5 Δ5,8,11,14,17) and docosahexaenoic acid (DHA; 22:6 Δ4,7,10,13,16,19) have been shown to have significant roles in human health. Currently the primary dietary source of these fatty acids are marine fish; however, the increasing demand for fish and fish oil (in particular the expansion of the aquaculture industry) is placing enormous pressure on diminishing marine stocks. Such overfishing and concerns related to pollution in the marine environment have directed research towards the development of a viable alternative sustainable source of VLC-PUFAs. As a result, the last decade has seen many genes encoding the primary VLC-PUFA biosynthetic activities identified and characterized. This has allowed the reconstitution of the VLC-PUFA biosynthetic pathway in oilseed crops, producing transgenic plants engineered to accumulate ω-3 VLC-PUFAs at levels approaching those found in native marine organisms. Moreover, as a result of these engineering activities, knowledge of the fundamental processes surrounding acyl exchange and lipid remodelling has progressed. The application of new technologies, for example lipidomics and next-generation sequencing, is providing a better understanding of seed oil biosynthesis and opportunities for increasing the production of unusual fatty acids. Certainly, it is now possible to modify the composition of plant oils successfully, and, in this review, the most recent developments in this field and the challenges of producing VLC-PUFAs in the seed oil of higher plants will be described.

  17. Directed natural product biosynthesis gene cluster capture and expression in the model bacterium Bacillus subtilis

    KAUST Repository

    Li, Yongxin; Li, Zhongrui; Yamanaka, Kazuya; Xu, Ying; Zhang, Weipeng; Vlamakis, Hera; Kolter, Roberto; Moore, Bradley S.; Qian, Pei-Yuan

    2015-01-01

    validating this direct cloning plug-and-playa approach with surfactin, we genetically interrogated amicoumacin biosynthetic gene cluster from the marine isolate Bacillus subtilis 1779. Its heterologous expression allowed us to explore an unusual maturation

  18. Overexpression of snapdragon Delila (Del) gene in tobacco enhances anthocyanin accumulation and abiotic stress tolerance.

    Science.gov (United States)

    Naing, Aung Htay; Park, Kyeung Il; Ai, Trinh Ngoc; Chung, Mi Young; Han, Jeung Sul; Kang, Young-Wha; Lim, Ki Byung; Kim, Chang Kil

    2017-03-23

    Rosea1 (Ros1) and Delila (Del) co-expression controls anthocyanin accumulation in snapdragon flowers, while their overexpression in tomato strongly induces anthocyanin accumulation. However, little data exist on how Del expression alone influences anthocyanin accumulation. In tobacco (Nicotiana tabacum 'Xanthi'), Del expression enhanced leaf and flower anthocyanin production through regulating NtCHS, NtCHI, NtF3H, NtDFR, and NtANS transcript levels. Transgenic lines displayed different anthocyanin colors (e.g., pale red: T 0 -P, red: T 0 -R, and strong red: T 0 -S), resulting from varying levels of biosynthetic gene transcripts. Under salt stress, the T 2 generation had higher total polyphenol content, radical (DPPH, ABTS) scavenging activities, antioxidant-related gene expression, as well as overall greater salt and drought tolerance than wild type (WT). We propose that Del overexpression elevates transcript levels of anthocyanin biosynthetic and antioxidant-related genes, leading to enhanced anthocyanin production and antioxidant activity. The resultant increase of anthocyanin and antioxidant activity improves abiotic stress tolerance.

  19. Assembly of a novel biosynthetic pathway for production of the plant flavonoid fisetin in Escherichia coli.

    Science.gov (United States)

    Stahlhut, Steen G; Siedler, Solvej; Malla, Sailesh; Harrison, Scott J; Maury, Jérôme; Neves, Ana Rute; Forster, Jochen

    2015-09-01

    Plant secondary metabolites are an underutilized pool of bioactive molecules for applications in the food, pharma and nutritional industries. One such molecule is fisetin, which is present in many fruits and vegetables and has several potential health benefits, including anti-cancer, anti-viral and anti-aging activity. Moreover, fisetin has recently been shown to prevent Alzheimer's disease in mice and to prevent complications associated with diabetes type I. Thus far the biosynthetic pathway of fisetin in plants remains elusive. Here, we present the heterologous assembly of a novel fisetin pathway in Escherichia coli. We propose a novel biosynthetic pathway from the amino acid, tyrosine, utilizing nine heterologous enzymes. The pathway proceeds via the synthesis of two flavanones never produced in microorganisms before--garbanzol and resokaempferol. We show for the first time a functional biosynthetic pathway and establish E. coli as a microbial platform strain for the production of fisetin and related flavonols. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  20. Alteration in expression of defence genes in Pisum sativum after exposure to supplementary ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Strid, A.

    1993-01-01

    Alterations in the amounts of mRNA for different types of defence genes after exposure of peas to supplementary ultraviolet-B radiation are demonstrated. The expression of the genes which encode the chalcone synthase of the flavonoid biosynthetic pathway and glutathione reductase was induced, while a decrease was found for the chloroplastic radical-scavenging enzyme, superoxide dismutase. (author)

  1. Kinetics of Nif gene expression in a nitrogen-fixing bacterium.

    Science.gov (United States)

    Poza-Carrión, César; Jiménez-Vicente, Emilio; Navarro-Rodríguez, Mónica; Echavarri-Erasun, Carlos; Rubio, Luis M

    2014-02-01

    Nitrogen fixation is a tightly regulated trait. Switching from N2 fixation-repressing conditions to the N2-fixing state is carefully controlled in diazotrophic bacteria mainly because of the high energy demand that it imposes. By using quantitative real-time PCR and quantitative immunoblotting, we show here how nitrogen fixation (nif) gene expression develops in Azotobacter vinelandii upon derepression. Transient expression of the transcriptional activator-encoding gene, nifA, was followed by subsequent, longer-duration waves of expression of the nitrogenase biosynthetic and structural genes. Importantly, expression timing, expression levels, and NifA dependence varied greatly among the nif operons. Moreover, the exact concentrations of Nif proteins and their changes over time were determined for the first time. Nif protein concentrations were exquisitely balanced, with FeMo cofactor biosynthetic proteins accumulating at levels 50- to 100-fold lower than those of the structural proteins. Mutants lacking nitrogenase structural genes or impaired in FeMo cofactor biosynthesis showed overenhanced responses to derepression that were proportional to the degree of nitrogenase activity impairment, consistent with the existence of at least two negative-feedback regulatory mechanisms. The first such mechanism responded to the levels of fixed nitrogen, whereas the second mechanism appeared to respond to the levels of the mature NifDK component. Altogether, these findings provide a framework to engineer N2 fixation in nondiazotrophs.

  2. Characterization and engineering of thermophilic aldolases : synthesizing nitrogen-heterocycles in biosynthetic routes

    NARCIS (Netherlands)

    Wolterink-van Loo, S.

    2009-01-01

    Aldolases are enzymes that catalyze reactions in both degradation and biosynthetic pathways in vivo and have been discovered in all domains of life. they. An interesting property of aldolases is that they can synthesize carbon-carbon bonds, generating a new stereogenic centre. As enzymes are

  3. The carotenoid biosynthetic and catabolic genes in wheat and their association with yellow pigments.

    Science.gov (United States)

    Colasuonno, Pasqualina; Lozito, Maria Luisa; Marcotuli, Ilaria; Nigro, Domenica; Giancaspro, Angelica; Mangini, Giacomo; De Vita, Pasquale; Mastrangelo, Anna Maria; Pecchioni, Nicola; Houston, Kelly; Simeone, Rosanna; Gadaleta, Agata; Blanco, Antonio

    2017-01-31

    In plants carotenoids play an important role in the photosynthetic process and photo-oxidative protection, and are the substrate for the synthesis of abscisic acid and strigolactones. In addition to their protective role as antioxidants and precursors of vitamin A, in wheat carotenoids are important as they influence the colour (whiteness vs. yellowness) of the grain. Understanding the genetic basis of grain yellow pigments, and identifying associated markers provide the basis for improving wheat quality by molecular breeding. Twenty-four candidate genes involved in the biosynthesis and catabolism of carotenoid compounds have been identified in wheat by comparative genomics. Single nucleotide polymorphisms (SNPs) found in the coding sequences of 19 candidate genes allowed their chromosomal location and accurate map position on two reference consensus maps to be determined. The genome-wide association study based on genotyping a tetraploid wheat collection with 81,587 gene-associated SNPs validated quantitative trait loci (QTLs) previously detected in biparental populations and discovered new QTLs for grain colour-related traits. Ten carotenoid genes mapped in chromosome regions underlying pigment content QTLs indicating possible functional relationships between candidate genes and the trait. The availability of linked, candidate gene-based markers can facilitate breeding wheat cultivars with desirable levels of carotenoids. Identifying QTLs linked to carotenoid pigmentation can contribute to understanding genes underlying carotenoid accumulation in the wheat kernels. Together these outputs can be combined to exploit the genetic variability of colour-related traits for the nutritional and commercial improvement of wheat products.

  4. Early phenylpropanoid biosynthetic steps in Cannabis sativa: link between genes and metabolites.

    Science.gov (United States)

    Docimo, Teresa; Consonni, Roberto; Coraggio, Immacolata; Mattana, Monica

    2013-06-28

    Phenylalanine ammonia-lyase (PAL), Cinnamic acid 4-hydroxylase (C4H) and 4-Coumarate: CoA ligase (4CL) catalyze the first three steps of the general phenylpropanoid pathway whereas chalcone synthase (CHS) catalyzes the first specific step towards flavonoids production. This class of specialized metabolites has a wide range of biological functions in plant development and defence and a broad spectrum of therapeutic activities for human health. In this study, we report the isolation of hemp PAL and 4CL cDNA and genomic clones. Through in silico analysis of their deduced amino acid sequences, more than an 80% identity with homologues genes of other plants was shown and phylogenetic relationships were highlighted. Quantitative expression analysis of the four above mentioned genes, PAL and 4CL enzymatic activities, lignin content and NMR metabolite fingerprinting in different Cannabis sativa tissues were evaluated. Furthermore, the use of different substrates to assay PAL and 4CL enzymatic activities indicated that different isoforms were active in different tissues. The diversity in secondary metabolites content observed in leaves (mainly flavonoids) and roots (mainly lignin) was discussed in relation to gene expression and enzymatic activities data.

  5. Early Phenylpropanoid Biosynthetic Steps in Cannabis sativa: Link between Genes and Metabolites

    Directory of Open Access Journals (Sweden)

    Immacolata Coraggio

    2013-06-01

    Full Text Available Phenylalanine ammonia-lyase (PAL, Cinnamic acid 4-hydroxylase (C4H and 4-Coumarate: CoA ligase (4CL catalyze the first three steps of the general phenylpropanoid pathway whereas chalcone synthase (CHS catalyzes the first specific step towards flavonoids production. This class of specialized metabolites has a wide range of biological functions in plant development and defence and a broad spectrum of therapeutic activities for human health. In this study, we report the isolation of hemp PAL and 4CL cDNA and genomic clones. Through in silico analysis of their deduced amino acid sequences, more than an 80% identity with homologues genes of other plants was shown and phylogenetic relationships were highlighted. Quantitative expression analysis of the four above mentioned genes, PAL and 4CL enzymatic activities, lignin content and NMR metabolite fingerprinting in different Cannabis sativa tissues were evaluated. Furthermore, the use of different substrates to assay PAL and 4CL enzymatic activities indicated that different isoforms were active in different tissues. The diversity in secondary metabolites content observed in leaves (mainly flavonoids and roots (mainly lignin was discussed in relation to gene expression and enzymatic activities data.

  6. Regulation of the anthocyanin biosynthetic pathway by the TTG1/bHLH/Myb transcriptional complex in Arabidopsis seedlings.

    Science.gov (United States)

    Gonzalez, Antonio; Zhao, Mingzhe; Leavitt, John M; Lloyd, Alan M

    2008-03-01

    In all higher plants studied to date, the anthocyanin pigment pathway is regulated by a suite of transcription factors that include Myb, bHLH and WD-repeat proteins. However, in Arabidopsis thaliana, the Myb regulators remain to be conclusively identified, and little is known about anthocyanin pathway regulation by TTG1-dependent transcriptional complexes. Previous overexpression of the PAP1 Myb suggested that genes from the entire phenylpropanoid pathway are targets of regulation by Myb/bHLH/WD-repeat complexes in Arabidopsis, in contrast to other plants. Here we demonstrate that overexpression of Myb113 or Myb114 results in substantial increases in pigment production similar to those previously seen as a result of over-expression of PAP1, and pigment production in these overexpressors remains TTG1- and bHLH-dependent. Also, plants harboring an RNAi construct targeting PAP1 and three Myb candidates (PAP2, Myb113 and Myb114) showed downregulated Myb gene expression and obvious anthocyanin deficiencies. Correlated with these anthocyanin deficiencies is downregulation of the same late anthocyanin structural genes that are downregulated in ttg1 and bHLH anthocyanin mutants. Expression studies using GL3:GR and TTG1:GR fusions revealed direct regulation of the late biosynthetic genes only. Functional diversification between GL3 and EGL3 with regard to activation of gene targets was revealed by GL3:GR studies in single and double bHLH mutant seedlings. Expression profiles for Myb and bHLH regulators are also presented in the context of pigment production in young seedlings.

  7. Comprehensive annotation of secondary metabolite biosynthetic genes and gene clusters of Aspergillus nidulans, A. fumigatus, A. niger and A. oryzae

    Science.gov (United States)

    2013-01-01

    Background Secondary metabolite production, a hallmark of filamentous fungi, is an expanding area of research for the Aspergilli. These compounds are potent chemicals, ranging from deadly toxins to therapeutic antibiotics to potential anti-cancer drugs. The genome sequences for multiple Aspergilli have been determined, and provide a wealth of predictive information about secondary metabolite production. Sequence analysis and gene overexpression strategies have enabled the discovery of novel secondary metabolites and the genes involved in their biosynthesis. The Aspergillus Genome Database (AspGD) provides a central repository for gene annotation and protein information for Aspergillus species. These annotations include Gene Ontology (GO) terms, phenotype data, gene names and descriptions and they are crucial for interpreting both small- and large-scale data and for aiding in the design of new experiments that further Aspergillus research. Results We have manually curated Biological Process GO annotations for all genes in AspGD with recorded functions in secondary metabolite production, adding new GO terms that specifically describe each secondary metabolite. We then leveraged these new annotations to predict roles in secondary metabolism for genes lacking experimental characterization. As a starting point for manually annotating Aspergillus secondary metabolite gene clusters, we used antiSMASH (antibiotics and Secondary Metabolite Analysis SHell) and SMURF (Secondary Metabolite Unknown Regions Finder) algorithms to identify potential clusters in A. nidulans, A. fumigatus, A. niger and A. oryzae, which we subsequently refined through manual curation. Conclusions This set of 266 manually curated secondary metabolite gene clusters will facilitate the investigation of novel Aspergillus secondary metabolites. PMID:23617571

  8. EncM, a versatile enterocin biosynthetic enzyme involved in Favorskii oxidative rearrangement, aldol condensation, and heterocycle-forming reactions

    Science.gov (United States)

    Xiang, Longkuan; Kalaitzis, John A.; Moore, Bradley S.

    2004-01-01

    The bacteriostatic natural product enterocin from the marine microbe “Streptomyces maritimus” has an unprecedented carbon skeleton that is derived from an aromatic polyketide biosynthetic pathway. Its caged tricyclic, nonaromatic core is derived from a linear poly-β-ketide precursor that formally undergoes a Favorskii-like oxidative rearrangement. In vivo characterization of the gene encM through mutagenesis and heterologous biosynthesis demonstrated that its protein product not only is solely responsible for the oxidative C—C rearrangement, but also facilitates two aldol condensations plus two heterocycle forming reactions. In total, at least five chiral centers and four rings are generated by this multifaceted flavoprotein. Heterologous expression of the enterocin biosynthesis genes encABCDLMN in Streptomyces lividans resulted in the formation of the rearranged metabolite desmethyl-5-deoxyenterocin and the shunt products wailupemycins D-G. Addition of the methyltransferase gene encK, which was previously proposed through mutagenesis to additionally assist EncM in the Favorskii rearrangement, shifted the production to the O-methyl derivative 5-deoxyenterocin. The O-methyltransferase EncK seems to be specific for the pyrone ring of enterocin, because bicyclic polyketides bearing pyrone rings are not methylated in vivo. Expression of encM with different combinations of homologous actinorhodin biosynthesis genes did not result in the production of oxidatively rearranged enterocin-actinorhodin hybrid compounds as anticipated, suggesting that wild-type EncM may be specific for its endogenous type II polyketide synthase or for benzoyl-primed polyketide precursors. PMID:15505225

  9. De Novo Transcriptomes of Forsythia koreana Using a Novel Assembly Method: Insight into Tissue- and Species-Specific Expression of Lignan Biosynthesis-Related Gene.

    Directory of Open Access Journals (Sweden)

    Akira Shiraishi

    Full Text Available Forsythia spp. are perennial woody plants which are one of the most extensively used medicinal sources of Chinese medicines and functional diets owing to their lignan contents. Lignans have received widespread attention as leading compounds in the development of antitumor drugs and healthy diets for reducing the risks of lifestyle-related diseases. However, the molecular basis of Forsythia has yet to be established. In this study, we have verified de novo deep transcriptome of Forsythia koreana leaf and callus using the Illumina HiSeq 1500 platform. A total of 89 million reads were assembled into 116,824 contigs using Trinity, and 1,576 of the contigs displayed the sequence similarity to the enzymes responsible for plant specialized metabolism including lignan biosynthesis. Notably, gene ontology (GO analysis indicated the remarkable enrichment of lignan-biosynthetic enzyme genes in the callus transcriptome. Nevertheless, precise annotation and molecular phylogenetic analyses were hindered by partial sequences of open reading frames (ORFs of the Trinity-based contigs. To obtain more numerous contigs harboring a full-length ORF, we developed a novel overlapping layout consensus-based procedure, virtual primer-based sequence reassembly (VP-seq. VP-seq elucidated 709 full-length ORFs, whereas only 146 full-length ORFs were assembled by Trinity. The comparison of expression profiles of leaf and callus using VP-seq-based full-length ORFs revealed 50-fold upregulation of secoisolariciresinol dehydrogenase (SIRD in callus. Expression and phylogenetic cluster analyses predicted candidates for matairesinol-glucosylating enzymes. We also performed VP-seq analysis of lignan-biosynthetic enzyme genes in the transcriptome data of other lignan-rich plants, Linum flavum, Linum usitatissimum and Podophyllum hexandrum. The comparative analysis indicated both common gene clusters involved in biosynthesis upstream of matairesinol such as SIRD and plant lineage

  10. Detergent insolubility of alkaline phosphatase during biosynthetic transport and endocytosis. Role of cholesterol

    NARCIS (Netherlands)

    Cerneus, D. P.; Ueffing, E.; Posthuma, G.; Strous, G. J.; van der Ende, A.

    1993-01-01

    Alkaline phosphatase is anchored to the outer leaflet of the plasma membrane by a covalently attached glycosyl-phosphatidylinositol anchor. We have studied the biosynthetic transport and endocytosis of alkaline phosphatase in the choriocarcinoma cell line BeWo, which endogenously expresses this

  11. Biosynthesis of actinorhodin and related antibiotics: discovery of alternative routes for quinone formation encoded in the act gene cluster.

    Science.gov (United States)

    Okamoto, Susumu; Taguchi, Takaaki; Ochi, Kozo; Ichinose, Koji

    2009-02-27

    All known benzoisochromanequinone (BIQ) biosynthetic gene clusters carry a set of genes encoding a two-component monooxygenase homologous to the ActVA-ORF5/ActVB system for actinorhodin biosynthesis in Streptomyces coelicolor A3(2). Here, we conducted molecular genetic and biochemical studies of this enzyme system. Inactivation of actVA-ORF5 yielded a shunt product, actinoperylone (ACPL), apparently derived from 6-deoxy-dihydrokalafungin. Similarly, deletion of actVB resulted in accumulation of ACPL, indicating a critical role for the monooxygenase system in C-6 oxygenation, a biosynthetic step common to all BIQ biosyntheses. Furthermore, in vitro, we showed a quinone-forming activity of the ActVA-ORF5/ActVB system in addition to that of a known C-6 monooxygenase, ActVA-ORF6, by using emodinanthrone as a model substrate. Our results demonstrate that the act gene cluster encodes two alternative routes for quinone formation by C-6 oxygenation in BIQ biosynthesis.

  12. The Genome of Tolypocladium inflatum: Evolution, Organization, and Expression of the Cyclosporin Biosynthetic Gene Cluster

    Science.gov (United States)

    Bushley, Kathryn E.; Raja, Rajani; Jaiswal, Pankaj; Cumbie, Jason S.; Nonogaki, Mariko; Boyd, Alexander E.; Owensby, C. Alisha; Knaus, Brian J.; Elser, Justin; Miller, Daniel; Di, Yanming; McPhail, Kerry L.; Spatafora, Joseph W.

    2013-01-01

    The ascomycete fungus Tolypocladium inflatum, a pathogen of beetle larvae, is best known as the producer of the immunosuppressant drug cyclosporin. The draft genome of T. inflatum strain NRRL 8044 (ATCC 34921), the isolate from which cyclosporin was first isolated, is presented along with comparative analyses of the biosynthesis of cyclosporin and other secondary metabolites in T. inflatum and related taxa. Phylogenomic analyses reveal previously undetected and complex patterns of homology between the nonribosomal peptide synthetase (NRPS) that encodes for cyclosporin synthetase (simA) and those of other secondary metabolites with activities against insects (e.g., beauvericin, destruxins, etc.), and demonstrate the roles of module duplication and gene fusion in diversification of NRPSs. The secondary metabolite gene cluster responsible for cyclosporin biosynthesis is described. In addition to genes necessary for cyclosporin biosynthesis, it harbors a gene for a cyclophilin, which is a member of a family of immunophilins known to bind cyclosporin. Comparative analyses support a lineage specific origin of the cyclosporin gene cluster rather than horizontal gene transfer from bacteria or other fungi. RNA-Seq transcriptome analyses in a cyclosporin-inducing medium delineate the boundaries of the cyclosporin cluster and reveal high levels of expression of the gene cluster cyclophilin. In medium containing insect hemolymph, weaker but significant upregulation of several genes within the cyclosporin cluster, including the highly expressed cyclophilin gene, was observed. T. inflatum also represents the first reference draft genome of Ophiocordycipitaceae, a third family of insect pathogenic fungi within the fungal order Hypocreales, and supports parallel and qualitatively distinct radiations of insect pathogens. The T. inflatum genome provides additional insight into the evolution and biosynthesis of cyclosporin and lays a foundation for further investigations of the role

  13. Use of [75Se]selenomethionine in immunoglobulin biosynthetic studies

    International Nuclear Information System (INIS)

    Gutman, G.A.; Warner, N.L.; Harris, A.W.; Bowles, A.

    1978-01-01

    The gamma-emitting amino acid analog, [ 75 Se] selenomethionine, has been used as a biosynthetic label for immunoglobulins secreted by plasmacytomas in tissue culture. The secreted products are structurally intact with respect to their antibody combining sites and their class and allotype antigenic specificities. A component of [ 75 Se] selenomethionine preparations was found to bind to fetal calf serum proteins, in a manner releasable by mercaptoethanol, but not by sodium dodecyl sulfate and urea. Methods for circumventing the problems caused by this binding are described. (Auth.)

  14. Genetic determination of the meso-diaminopimelate biosynthetic pathway of mycobacteria.

    OpenAIRE

    Cirillo, J. D.; Weisbrod, T. R.; Banerjee, A.; Bloom, B. R.; Jacobs, W. R.

    1994-01-01

    The increasing incidence of multiple-drug-resistant mycobacterial infections indicates that the development of new methods for treatment of mycobacterial diseases should be a high priority. meso-Diaminopimelic acid (DAP), a key component of a highly immunogenic subunit of the mycobacterial peptidoglycan layer, has been implicated as a potential virulence factor. The mycobacterial DAP biosynthetic pathway could serve as a target for design of new antimycobacterial agents as well as the constru...

  15. Location, formation and biosynthetic regulation of cellulases in the gliding bacteria Cytophaga hutchinsonii

    Directory of Open Access Journals (Sweden)

    Elijah Johnson

    2006-01-01

    Full Text Available An analysis of the recently published genome sequence of Cytophagahutchinsonii revealed an unusual collection of genes for an organism that can attackcrystalline cellulose. Consequently, questions were being raised by cellulase scientists, as towhat mechanism this organism uses to degrade its insoluble substrates. Cellulose, being ahighly polymeric compound and insoluble in water, cannot enter the cell walls ofmicroorganisms. Cellulose-degrading enzymes have therefore to be located on the surface ofthe cell wall or released extracellularly. The location of most cellulase enzymes has beenstudied. However, basic information on C. hutchinsonii cellulases is almost non-existent. Inthe present study, the location, formation and biosynthetic regulation of cellulases in C.hutchinsonii were demonstrated on different substrates. Various fractions isolated from C.hutchinsonii after cell rupture were assayed for carboxymethyl-cellulase activity (CMC.The cellulases were found to be predominantly cell-free during active growth on solka-flok,although 30% of activity was recorded on cell-bound enzymes. Relatively little CM-cellulase was formed when cells were grown on glucose and cellobiose. Apparently glucoseor labile substrates such as cellobiose seem to repress the formation of CM-cellulase. Thesefindings should provide some insight into possible hydrolysis mechanisms by C.hutchinsonii.

  16. Involvement of Trichoderma trichothecenes in the biocontrol activity and in the induction of plant defense related genes

    Science.gov (United States)

    Trichoderma species produce trichothecenes, most notably trichodermin and harzianum A (HA), by a biosynthetic pathway in which several of the involved proteins have significant differences in functionality, compared to their Fusarium orthologues. In addition, the genes encoding these proteins show a...

  17. Redox Impact on Starch Biosynthetic Enzymes in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Skryhan, Katsiaryna

    Summary The thesis provides new insight into the influence of the plant cell redox state on the transient starch metabolism in Arabidopsis thaliana with a focus on starch biosynthetic enzymes. Two main hypotheses forms the basis of this thesis: 1) photosynthesis and starch metabolism are coordina......Summary The thesis provides new insight into the influence of the plant cell redox state on the transient starch metabolism in Arabidopsis thaliana with a focus on starch biosynthetic enzymes. Two main hypotheses forms the basis of this thesis: 1) photosynthesis and starch metabolism...... are coordinated by the redox state of the cell via post-translational modification of the starch metabolic enzymes containing redox active cysteine residues and these cysteine residues became cross-linked upon oxidation providing a conformational change leading to activity loss; 2) cysteine residues...... of chloroplast enzymes can play a role not only in enzyme activity and redox sensitivity but also in protein folding and stability upon oxidation. Several redox sensitive enzymes identified in this study can serve as potential targets to control the carbon flux to and from starch during the day and night...

  18. Neurosteroid biosynthetic pathway changes in substantia nigra and caudate nucleus in Parkinson's disease

    NARCIS (Netherlands)

    Luchetti, Sabina; Bossers, Koen; Frajese, Giovanni Vanni; Swaab, Dick F.

    2010-01-01

    There is emerging evidence from animal studies for a neuroprotective role of sex steroids in neurodegenerative diseases, but studies in human brain are lacking. We have carried out an extensive study of the neurosteroid biosynthetic pathways in substantia nigra (SN), caudate nucleus (CN) and putamen

  19. Open reading frame 176 in the photosynthesis gene cluster of Rhodobacter capsulatus encodes idi, a gene for isopentenyl diphosphate isomerase.

    OpenAIRE

    Hahn, F M; Baker, J A; Poulter, C D

    1996-01-01

    Isopentenyl diphosphate (IPP) isomerase catalyzes an essential activation step in the isoprenoid biosynthetic pathway. A database search based on probes from the highly conserved regions in three eukaryotic IPP isomerases revealed substantial similarity with ORF176 in the photosynthesis gene cluster in Rhodobacter capsulatus. The open reading frame was cloned into an Escherichia coli expression vector. The encoded 20-kDa protein, which was purified in two steps by ion exchange and hydrophobic...

  20. A kinetic model for the penicillin biosynthetic pathway in

    DEFF Research Database (Denmark)

    Nielsen, Jens; Jørgensen, Henrik

    1996-01-01

    A kinetic model for the first two steps in the penicillin biosynthetic pathway, i.e. the ACV synthetase (ACVS) and the isopenicillin N synthetase (IPNS) is proposed. The model is based on Michaelis-Menten type kinetics with non-competitive inhibition of the ACVS by ACV, and competitive inhibition...... of the IPNS by glutathione. The model predicted flux through the pathway corresponds well with the measured rate of penicillin biosynthesis. From the kinetic model the elasticity coefficients and the flux control coefficients are calculated throughout a fed-batch cultivation, and it is found...

  1. Metabolic and functional diversity of saponins, biosynthetic intermediates and semi-synthetic derivatives

    Science.gov (United States)

    Moses, Tessa; Papadopoulou, Kalliope K.

    2014-01-01

    Saponins are widely distributed plant natural products with vast structural and functional diversity. They are typically composed of a hydrophobic aglycone, which is extensively decorated with functional groups prior to the addition of hydrophilic sugar moieties, to result in surface-active amphipathic compounds. The saponins are broadly classified as triterpenoids, steroids or steroidal glycoalkaloids, based on the aglycone structure from which they are derived. The saponins and their biosynthetic intermediates display a variety of biological activities of interest to the pharmaceutical, cosmetic and food sectors. Although their relevance in industrial applications has long been recognized, their role in plants is underexplored. Recent research on modulating native pathway flux in saponin biosynthesis has demonstrated the roles of saponins and their biosynthetic intermediates in plant growth and development. Here, we review the literature on the effects of these molecules on plant physiology, which collectively implicate them in plant primary processes. The industrial uses and potential of saponins are discussed with respect to structure and activity, highlighting the undoubted value of these molecules as therapeutics. PMID:25286183

  2. Blockage of the pyrimidine biosynthetic pathway affects riboflavin production in Ashbya gossypii.

    Science.gov (United States)

    Silva, Rui; Aguiar, Tatiana Q; Domingues, Lucília

    2015-01-10

    The Ashbya gossypii riboflavin biosynthetic pathway and its connection with the purine pathway have been well studied. However, the outcome of genetic alterations in the pyrimidine pathway on riboflavin production by A. gossypii had not yet been assessed. Here, we report that the blockage of the de novo pyrimidine biosynthetic pathway in the recently generated A. gossypii Agura3 uridine/uracil auxotrophic strain led to improved riboflavin production on standard agar-solidified complex medium. When extra uridine/uracil was supplied, the production of riboflavin by this auxotroph was repressed. High concentrations of uracil hampered this (and the parent) strain growth, whereas excess uridine favored the A. gossypii Agura3 growth. Considering that the riboflavin and the pyrimidine pathways share the same precursors and that riboflavin overproduction may be triggered by nutritional stress, we suggest that overproduction of riboflavin by the A. gossypii Agura3 may occur as an outcome of a nutritional stress response and/or of an increased availability in precursors for riboflavin biosynthesis, due to their reduced consumption by the pyrimidine pathway. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Plant isoflavone and isoflavanone O-methyltransferase genes

    Science.gov (United States)

    Broeckling, Bettina E.; Liu, Chang-Jun; Dixon, Richard A.

    2014-08-19

    The invention provides enzymes that encode O-methyltransferases (OMTs) from Medicago truncatula that allow modification to plant (iso)flavonoid biosynthetic pathways. In certain aspects of the invention, the genes encoding these enzymes are provided. The invention therefore allows the modification of plants for isoflavonoid content. Transgenic plants comprising such enzymes are also provided, as well as methods for improving disease resistance in plants. Methods for producing food and nutraceuticals, and the resulting compositions, are also provided.

  4. Chitosan oligosaccharide and salicylic acid up-regulate gene expression differently in relation to the biosynthesis of artemisinin in Artemisia annua L

    DEFF Research Database (Denmark)

    Yin, Heng; Kjær, Anders; Fretté, Xavier

    2012-01-01

    oligosaccharide (COS) and salicylic acid (SA) on both artemisinin production and gene expression related to the biosynthetic pathway of artemisinin. COS up-regulated the transcriptional levels of the genes ADS and TTG1 2.5 fold and 1.8 fold after 48 h individually, whereas SA only up-regulated ADS 2.0 fold after...

  5. Targeted capture and heterologous expression of the Pseudoalteromonas alterochromide gene cluster in Escherichia coli represents a promising natural product exploratory platform.

    Science.gov (United States)

    Ross, Avena C; Gulland, Lauren E S; Dorrestein, Pieter C; Moore, Bradley S

    2015-04-17

    Marine pseudoalteromonads represent a very promising source of biologically important natural product molecules. To access and exploit the full chemical capacity of these cosmopolitan Gram-(-) bacteria, we sought to apply universal synthetic biology tools to capture, refactor, and express biosynthetic gene clusters for the production of complex organic compounds in reliable host organisms. Here, we report a platform for the capture of proteobacterial gene clusters using a transformation-associated recombination (TAR) strategy coupled with direct pathway manipulation and expression in Escherichia coli. The ~34 kb pathway for production of alterochromide lipopeptides by Pseudoalteromonas piscicida JCM 20779 was captured and heterologously expressed in E. coli utilizing native and E. coli-based T7 promoter sequences. Our approach enabled both facile production of the alterochromides and in vivo interrogation of gene function associated with alterochromide's unusual brominated lipid side chain. This platform represents a simple but effective strategy for the discovery and biosynthetic characterization of natural products from marine proteobacteria.

  6. Spliced X-box binding protein 1 couples the unfolded protein response to hexosamine biosynthetic pathway.

    Science.gov (United States)

    Wang, Zhao V; Deng, Yingfeng; Gao, Ningguo; Pedrozo, Zully; Li, Dan L; Morales, Cyndi R; Criollo, Alfredo; Luo, Xiang; Tan, Wei; Jiang, Nan; Lehrman, Mark A; Rothermel, Beverly A; Lee, Ann-Hwee; Lavandero, Sergio; Mammen, Pradeep P A; Ferdous, Anwarul; Gillette, Thomas G; Scherer, Philipp E; Hill, Joseph A

    2014-03-13

    The hexosamine biosynthetic pathway (HBP) generates uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) for glycan synthesis and O-linked GlcNAc (O-GlcNAc) protein modifications. Despite the established role of the HBP in metabolism and multiple diseases, regulation of the HBP remains largely undefined. Here, we show that spliced X-box binding protein 1 (Xbp1s), the most conserved signal transducer of the unfolded protein response (UPR), is a direct transcriptional activator of the HBP. We demonstrate that the UPR triggers HBP activation via Xbp1s-dependent transcription of genes coding for key, rate-limiting enzymes. We further establish that this previously unrecognized UPR-HBP axis is triggered in a variety of stress conditions. Finally, we demonstrate a physiologic role for the UPR-HBP axis by showing that acute stimulation of Xbp1s in heart by ischemia/reperfusion confers robust cardioprotection in part through induction of the HBP. Collectively, these studies reveal that Xbp1s couples the UPR to the HBP to protect cells under stress. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Phytochemical and Biosynthetic Studies of Lignans, with a Focus on Indonesian Medicinal Plants

    NARCIS (Netherlands)

    Elfahmi, [No Value

    2006-01-01

    In this thesis phytochemical and biosynthetic studies of lignans are described. The focus is on the Indonesian medicinal plants Phyllanthus niruri and Piper cubeba and on two Linum species, Linum flavum and L. leonii, native to European countries. Both Indonesian plants are used in jamu. Jamu is the

  8. ATNT: an enhanced system for expression of polycistronic secondary metabolite gene clusters in Aspergillus niger.

    Science.gov (United States)

    Geib, Elena; Brock, Matthias

    2017-01-01

    Fungi are treasure chests for yet unexplored natural products. However, exploitation of their real potential remains difficult as a significant proportion of biosynthetic gene clusters appears silent under standard laboratory conditions. Therefore, elucidation of novel products requires gene activation or heterologous expression. For heterologous gene expression, we previously developed an expression platform in Aspergillus niger that is based on the transcriptional regulator TerR and its target promoter P terA . In this study, we extended this system by regulating expression of terR  by the doxycycline inducible Tet-on system. Reporter genes cloned under the control of the target promoter P terA remained silent in the absence of doxycycline, but were strongly expressed when doxycycline was added. Reporter quantification revealed that the coupled system results in about five times higher expression rates compared to gene expression under direct control of the Tet-on system. As production of secondary metabolites generally requires the expression of several biosynthetic genes, the suitability of the self-cleaving viral peptide sequence P2A was tested in this optimised expression system. P2A allowed polycistronic expression of genes required for Asp-melanin formation in combination with the gene coding for the red fluorescent protein tdTomato. Gene expression and Asp-melanin formation was prevented in the absence of doxycycline and strongly induced by addition of doxycycline. Fluorescence studies confirmed the correct subcellular localisation of the respective enzymes. This tightly regulated but strongly inducible expression system enables high level production of secondary metabolites most likely even those with toxic potential. Furthermore, this system is compatible with polycistronic gene expression and, thus, suitable for the discovery of novel natural products.

  9. Plasma Catecholamines (CA) and Gene Expression of CA Biosynthetic Enzymes in Adrenal Medulla and Sympathetic Ganglia of Rats Exposed to Single or Repeated Hypergravity

    Science.gov (United States)

    Petrak, J.; Jurani, M.; Baranovska, M.; Hapala, I.; Frollo, I.; Kvetnansky, R.

    2008-06-01

    The aim of this study was to evaluate plasma epinephrine (EPI) and norepinephrine (NE) levels in blood collected directly during a single or 8-times repeated centrifugation at hypergravity 4G, using remote controlled equipment. Plasma EPI levels showed a huge hypergravity-induced increase. After the last blood collection during hypergravity, the centrifuge was turned off and another blood sampling was performed immediately after the centrifuge decelerated and stopped (10 min). In these samples plasma EPI showed significantly lower levels compared to centrifugation intervals. Plasma NE levels showed none or small changes. Repeated exposure to hypergravity 4G (8 days for 60 min) eliminated the increase in plasma EPI levels at the 15 min interval but did not markedly affect plasma NE levels. To explain these findings we measured mRNA levels of CA biosynthetic enzymes tyrosine hydroxylase (TH), dopamine-β-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT) in the adrenal medulla (AM) and stellate ganglia (SG) of rats exposed to continuous hypergravity (2G) up to 6 days. In AM, TH, DBH and PNMT mRNA levels were significantly increased in intervals up to 3 days, however, after 6 day hypergravity exposure, no significant elevation was found. In SG, no significant changes in gene expression of CA enzymes were seen both after a single or repeated hypergravity. Thus, our data show that hypergravity highly activates the adrenomedullary system, whereas the sympathoneural system is not significantly changed. In conclusion, our results demonstrate that during repeated or continuous exposure of the organism to hypergravity the adrenomedullary system is adapted, whereas sympathoneural system is not affected.

  10. The oxalic acid biosynthetic activity of Burkholderia mallei is encoded by a single locus

    Science.gov (United States)

    Although it is known that oxalic acid provides a selective advantage to the secreting microbe, our understanding of how this acid is biosynthesized remains incomplete. This study reports the identification, cloning, and partial characterization of the oxalic acid biosynthetic enzyme from the animal ...

  11. An Integrated Metabolomic and Genomic Mining Workflow to Uncover the Biosynthetic Potential of Bacteria

    DEFF Research Database (Denmark)

    Månsson, Maria; Vynne, Nikolaj Grønnegaard; Klitgaard, Andreas

    2016-01-01

    Microorganisms are a rich source of bioactives; however, chemical identification is a major bottleneck. Strategies that can prioritize the most prolific microbial strains and novel compounds are of great interest. Here, we present an integrated approach to evaluate the biosynthetic richness in ba...

  12. Identification of loci and functional characterization of trichothecene biosynthesis genes in the filamentous fungus of the genus Trichoderma

    Science.gov (United States)

    Trichothecenes are mycotoxins produced by Trichoderma, Fusarium and at least four other genera in the fungal order Hypocreales. Fusarium has a trichothecene biosynthetic gene (TRI) cluster that encodes transport and regulatory proteins as well as most enzymes required for formation of the mycotoxin...

  13. Promzea: a pipeline for discovery of co-regulatory motifs in maize and other plant species and its application to the anthocyanin and phlobaphene biosynthetic pathways and the Maize Development Atlas.

    Science.gov (United States)

    Liseron-Monfils, Christophe; Lewis, Tim; Ashlock, Daniel; McNicholas, Paul D; Fauteux, François; Strömvik, Martina; Raizada, Manish N

    2013-03-15

    The discovery of genetic networks and cis-acting DNA motifs underlying their regulation is a major objective of transcriptome studies. The recent release of the maize genome (Zea mays L.) has facilitated in silico searches for regulatory motifs. Several algorithms exist to predict cis-acting elements, but none have been adapted for maize. A benchmark data set was used to evaluate the accuracy of three motif discovery programs: BioProspector, Weeder and MEME. Analysis showed that each motif discovery tool had limited accuracy and appeared to retrieve a distinct set of motifs. Therefore, using the benchmark, statistical filters were optimized to reduce the false discovery ratio, and then remaining motifs from all programs were combined to improve motif prediction. These principles were integrated into a user-friendly pipeline for motif discovery in maize called Promzea, available at http://www.promzea.org and on the Discovery Environment of the iPlant Collaborative website. Promzea was subsequently expanded to include rice and Arabidopsis. Within Promzea, a user enters cDNA sequences or gene IDs; corresponding upstream sequences are retrieved from the maize genome. Predicted motifs are filtered, combined and ranked. Promzea searches the chosen plant genome for genes containing each candidate motif, providing the user with the gene list and corresponding gene annotations. Promzea was validated in silico using a benchmark data set: the Promzea pipeline showed a 22% increase in nucleotide sensitivity compared to the best standalone program tool, Weeder, with equivalent nucleotide specificity. Promzea was also validated by its ability to retrieve the experimentally defined binding sites of transcription factors that regulate the maize anthocyanin and phlobaphene biosynthetic pathways. Promzea predicted additional promoter motifs, and genome-wide motif searches by Promzea identified 127 non-anthocyanin/phlobaphene genes that each contained all five predicted promoter

  14. Biosynthetic graft failure to replace infected infrainguinal bypass as developing infection due to Morganella morganii leading to disrupture of the anastomosis. Case report

    Directory of Open Access Journals (Sweden)

    Gladiol Zenunaj

    Full Text Available Introduction: Biosynthetic prosthesis has become the trend to carry out arterial reconstruction in infected sites since considered to be resistant to infection. Late graft occlusion is the only complication reported in literature so far. We report a case of biosynthetic graft infection which led to early detachment of the femoral anastomosis of a femoral-popliteal above-knee bypass. Material: A 76-year-old man developed groin infection 3 months later after performing an ePTFE femoral-popliteal above-knee bypass for critical limb ischemia. He was re-admitted for groin infection involving the vascular structures. Explantation of the existing bypass and its replacement with a biosynthetic graft (omniflow II was performed. Detachment of the proximal anastomosis occurred 6 days later leading to groin haematoma. Consequently, retroperitoneal access was performed for clamping the external iliac artery so as to control haemorrhage followed by explantation of the biosynthetic graft. An external iliac-popliteal above-knee bypass was tailored in order to save the limb and it was performed using a transobturator approach avoiding the infected site. In both cases bacterial cultures resulted positive for Morganella Morganii. The groin wound was treated separately with negative pressure medication healing definitively within 20 days and after 3-month follow-up the bypass was still patent. Conclusion: This is the first report of biosynthetic graft infection used for infrainguinal reconstruction leading to haemorrhage due to anastomosis disrupture. Using an extra-anatomical access for providing blood inflow to the leg avoiding the infected site and treating safely the groin wound with VAC therapy revealed to be a valid approach. Keywords: Infrainguinal bypass, Graft infection, Biosynthetic material, Graft occlusion, Negative pressure medication, Morganella morgani

  15. Use of (/sup 75/Se)selenomethionine in immunoglobulin biosynthetic studies

    Energy Technology Data Exchange (ETDEWEB)

    Gutman, G A; Warner, N L; Harris, A W; Bowles, A [Walter and Elisa Hall Institute of Medical Research, Victoria (Australia). Genetics Unit; Royal Melbourne Hospital, Victoria (Australia))

    1978-05-01

    The gamma-emitting amino acid analog, (/sup 75/Se) selenomethionine, has been used as a biosynthetic label for immunoglobulins secreted by plasmacytomas in tissue culture. The secreted products are structurally intact with respect to their antibody combining sites and their class and allotype antigenic specificities. A component of (/sup 75/Se) selenomethionine preparations was found to bind to fetal calf serum proteins, in a manner releasable by mercaptoethanol, but not by sodium dodecyl sulfate and urea. Methods for circumventing the problems caused by this binding are described.

  16. Transcriptional control of steroid biosynthesis genes in the Drosophila prothoracic gland by Ventral veins lacking and Knirps

    DEFF Research Database (Denmark)

    Danielsen, Erik Thomas; Møller, Morten Erik; Dorry, Elad

    2014-01-01

    Specialized endocrine cells produce and release steroid hormones that govern development, metabolism and reproduction. In order to synthesize steroids, all the genes in the biosynthetic pathway must be coordinately turned on in steroidogenic cells. In Drosophila, the steroid producing endocrine...

  17. Integration of Fermentation and Organic Synthesis: Studies of Roquefortine C and Biosynthetic Derivatives

    Science.gov (United States)

    Gober, Claire Marie

    Roquefortine C is one of the most ubiquitous indoline alkaloids of fungal origin. It has been isolated from over 30 different species of Penicillium fungi and has garnered attention in recent years for its role as a biosynthetic precursor to the triazaspirocyclic natural products glandicoline B, meleagrin, and oxaline. The triazaspirocyclic motif, which encompasses three nitrogen atoms attached to one quaternary carbon forming a spirocyclic scaffold, is a unique chemical moiety that has been shown to impart a wide array of biological activity, from anti-bacterial activity and antiproliferative activity against cancer cell lines to anti-biofouling against marine organisms. Despite the promise of these compounds in the pharmaceutical and materials industries, few syntheses of triazaspirocycles exist in the literature. The biosynthesis of roquefortine C-derived triazaspirocycles, however, provides inspiration for the synthesis of these compounds, namely through a nitrone-promoted transannular rearrangement. This type of internal rearrangement has never been carried out synthetically and would provide an efficient stereoselective synthesis of triazaspirocycles. This work encompasses efforts towards elucidating the biosynthetic pathway of roquefortine C-derived triazaspirocycles as well as synthetic efforts towards the construction of triazaspirocycles. Chapter 1 will discuss a large-scale fermentation procedure for the production of roquefortine C from Penicillium crustosum. Chapters 2 and 3 explore (through enzymatic and synthetic means, respectively) the formation of the key indoline nitrone moiety required for the proposed transannular rearrangement. Finally, chapter 4 will discuss synthetic efforts towards the synthesis of triazaspirocycles. This work has considerably enhanced our understanding of the roquefortine C biosynthetic pathway and the unique chemistry of this natural product, and our efforts towards the synthesis of triazaspirocycles will facilitate the

  18. Significant differences in gene expression and key genetic components associated with high growth vigor in populus section tacamahaca as revealed by comparative transcriptome analysis

    International Nuclear Information System (INIS)

    Cheng, S.; Chen, M.; Li, Y.; Wang, J.; Sun, X.; Wang, J.

    2017-01-01

    To identify genetic components involved in high growth vigor in F1 Populus section Tacamahaca hybrid plants, high and low vigor plants showing significant differences in apical dominance during a rapid growth period were selected. Apical bud transcriptomes of high and low-growth-vigor hybrids and their parents were analyzed using high-throughput RNA sequencing on an Illumina HiSeq 2000 platform. A total of 5,542 genes were differently expressed between high growth vigor hybrid and its parents, the genes were significantly enriched in pathways related to processes such as photosynthesis, pyrimidine ribonucleotide biosynthetic processes and nucleoside metabolic processes. There were 1410 differentially expressed genes between high and low growth vigor hybrid, the genes were mainly involved in photosynthesis, chlorophyll biosynthetic process, carbon fixation in photosynthetic organisms, porphyrin and chlorophyll metabolism and nitrogen metabolism. Moreover, a k-core of a gene co-expression network analysis was performed to identify the potential functions of genes related to high growth vigor. The functions of 8 selected candidate genes were associated mainly with circadian rhythm, water transport, cellulose catabolic processes, sucrose biosynthesis, pyrimidine ribonucleotide biosynthesis, purine nucleotide biosynthesis, meristem maintenance, and carbohydrate metabolism. Our results may contribute to a better understanding of the molecular basis of high growth vigor in hybrids and its regulation. (author)

  19. Overproduction of lactimidomycin by cross-overexpression of genes encoding Streptomyces antibiotic regulatory proteins.

    Science.gov (United States)

    Zhang, Bo; Yang, Dong; Yan, Yijun; Pan, Guohui; Xiang, Wensheng; Shen, Ben

    2016-03-01

    The glutarimide-containing polyketides represent a fascinating class of natural products that exhibit a multitude of biological activities. We have recently cloned and sequenced the biosynthetic gene clusters for three members of the glutarimide-containing polyketides-iso-migrastatin (iso-MGS) from Streptomyces platensis NRRL 18993, lactimidomycin (LTM) from Streptomyces amphibiosporus ATCC 53964, and cycloheximide (CHX) from Streptomyces sp. YIM56141. Comparative analysis of the three clusters identified mgsA and chxA, from the mgs and chx gene clusters, respectively, that were predicted to encode the PimR-like Streptomyces antibiotic regulatory proteins (SARPs) but failed to reveal any regulatory gene from the ltm gene cluster. Overexpression of mgsA or chxA in S. platensis NRRL 18993, Streptomyces sp. YIM56141 or SB11024, and a recombinant strain of Streptomyces coelicolor M145 carrying the intact mgs gene cluster has no significant effect on iso-MGS or CHX production, suggesting that MgsA or ChxA regulation may not be rate-limiting for iso-MGS and CHX production in these producers. In contrast, overexpression of mgsA or chxA in S. amphibiosporus ATCC 53964 resulted in a significant increase in LTM production, with LTM titer reaching 106 mg/L, which is five-fold higher than that of the wild-type strain. These results support MgsA and ChxA as members of the SARP family of positive regulators for the iso-MGS and CHX biosynthetic machinery and demonstrate the feasibility to improve glutarimide-containing polyketide production in Streptomyces strains by exploiting common regulators.

  20. Identification of a cis-regulatory element by transient analysis of co-ordinately regulated genes

    Directory of Open Access Journals (Sweden)

    Allan Andrew C

    2008-07-01

    Full Text Available Abstract Background Transcription factors (TFs co-ordinately regulate target genes that are dispersed throughout the genome. This co-ordinate regulation is achieved, in part, through the interaction of transcription factors with conserved cis-regulatory motifs that are in close proximity to the target genes. While much is known about the families of transcription factors that regulate gene expression in plants, there are few well characterised cis-regulatory motifs. In Arabidopsis, over-expression of the MYB transcription factor PAP1 (PRODUCTION OF ANTHOCYANIN PIGMENT 1 leads to transgenic plants with elevated anthocyanin levels due to the co-ordinated up-regulation of genes in the anthocyanin biosynthetic pathway. In addition to the anthocyanin biosynthetic genes, there are a number of un-associated genes that also change in expression level. This may be a direct or indirect consequence of the over-expression of PAP1. Results Oligo array analysis of PAP1 over-expression Arabidopsis plants identified genes co-ordinately up-regulated in response to the elevated expression of this transcription factor. Transient assays on the promoter regions of 33 of these up-regulated genes identified eight promoter fragments that were transactivated by PAP1. Bioinformatic analysis on these promoters revealed a common cis-regulatory motif that we showed is required for PAP1 dependent transactivation. Conclusion Co-ordinated gene regulation by individual transcription factors is a complex collection of both direct and indirect effects. Transient transactivation assays provide a rapid method to identify direct target genes from indirect target genes. Bioinformatic analysis of the promoters of these direct target genes is able to locate motifs that are common to this sub-set of promoters, which is impossible to identify with the larger set of direct and indirect target genes. While this type of analysis does not prove a direct interaction between protein and DNA

  1. Lactococcus lactis as expression host for the biosynthetic incorporation of tryptophan analogues into recombinant proteins

    NARCIS (Netherlands)

    El Khattabi, Mohamed; van Roosmalen, Maarten L.; Jager, Dennis; Metselaar, Heidi; Permentier, Hjalmar; Leenhouts, Kees; Broos, Jaap

    2008-01-01

    Incorporation of Trp (tryptophan) analogues into a protein may facilitate its structural analysis by spectroscopic techniques. Development of a biological system for the biosynthetic incorporation of such analogues into proteins is of considerable importance. The Gram-negative Escherichia coli is

  2. Reconstruction of the biosynthetic pathway for the core fungal polyketide scaffold rubrofusarin in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Rugbjerg, Peter; Naesby, Michael; Mortensen, Uffe Hasbro

    2013-01-01

    production in easily fermentable and genetically engineerable organisms, such as Saccharomyces cerevisiae and Escherichia coli are desirable. Rubrofusarin is an orange polyketide pigment that is a common intermediate in many different fungal biosynthetic pathways. RESULTS: In this study, we established...

  3. Decoding Biosynthetic Pathways in Plants by Pulse-Chase Strategies Using 13CO2 as a Universal Tracer

    Directory of Open Access Journals (Sweden)

    Adelbert Bacher

    2016-07-01

    Full Text Available 13CO2 pulse-chase experiments monitored by high-resolution NMR spectroscopy and mass spectrometry can provide 13C-isotopologue compositions in biosynthetic products. Experiments with a variety of plant species have documented that the isotopologue profiles generated with 13CO2 pulse-chase labeling are directly comparable to those that can be generated by the application of [U-13C6]glucose to aseptically growing plants. However, the application of the 13CO2 labeling technology is not subject to the experimental limitations that one has to take into account for experiments with [U-13C6]glucose and can be applied to plants growing under physiological conditions, even in the field. In practical terms, the results of biosynthetic studies with 13CO2 consist of the detection of pairs, triples and occasionally quadruples of 13C atoms that have been jointly contributed to the target metabolite, at an abundance that is well above the stochastic occurrence of such multiples. Notably, the connectivities of jointly transferred 13C multiples can have undergone modification by skeletal rearrangements that can be diagnosed from the isotopologue data. As shown by the examples presented in this review article, the approach turns out to be powerful in decoding the carbon topology of even complex biosynthetic pathways.

  4. Biosynthetic Studies on Water-Soluble Derivative 5c (DTX5c

    Directory of Open Access Journals (Sweden)

    José J. Fernández

    2012-10-01

    Full Text Available The dinoflagellate Prorocentrum belizeanum is responsible for the production of several toxins involved in the red tide phenomenon known as Diarrhetic Shellfish Poisoning (DSP. In this paper we report on the biosynthetic origin of an okadaic acid water-soluble ester derivative, DTX5c, on the basis of the spectroscopical analysis of 13C enriched samples obtained by addition of labelled sodium [l-13C], [2-13C] acetate to artificial cultures of this dinoflagellate.

  5. Activation of anthocyanin biosynthesis by expression of the radish R2R3-MYB transcription factor gene RsMYB1.

    Science.gov (United States)

    Lim, Sun-Hyung; Song, Ji-Hye; Kim, Da-Hye; Kim, Jae Kwang; Lee, Jong-Yeol; Kim, Young-Mi; Ha, Sun-Hwa

    2016-03-01

    RsMYB1, a MYB TF of red radish origin, was characterized as a positive regulator to transcriptionally activate the anthocyanin biosynthetic machinery by itself in Arabidopsis and tobacco plants. Anthocyanins, providing the bright red-orange to blue-violet colors, are flavonoid-derived pigments with strong antioxidant activity that have benefits for human health. We isolated RsMYB1, which encodes an R2R3-MYB transcription factor (TF), from red radish plants (Raphanus sativus L.) that accumulate high levels of anthocyanins. RsMYB1 shows higher expression in red radish than in common white radish, in both leaves and roots, at different growth stages. Consistent with RsMYB1 function as an anthocyanin-promoting TF, red radishes showed higher expression of all six anthocyanin biosynthetic and two anthocyanin regulatory genes. Transient expression of RsMYB1 in tobacco showed that RsMYB1 is a positive regulator of anthocyanin production with better efficiency than the basic helix-loop-helix (bHLH) TF gene B-Peru. Also, the synergistic effect of RsMYB1 with B-Peru was larger than the effect of the MYB TF gene mPAP1D with B-peru. Arabidopsis plants stably expressing RsMYB1 produced red pigmentation throughout the plant, accompanied by up-regulation of the six structural and two regulatory genes for anthocyanin production. This broad transcriptional activation of anthocyanin biosynthetic machinery in Arabidopsis included up-regulation of TRANSPARENT TESTA8, which encodes a bHLH TF. These results suggest that overexpression of RsMYB1 promotes anthocyanin production by triggering the expression of endogenous bHLH genes as potential binding partners for RsMYB1. In addition, RsMYB1-overexpressing Arabidopsis plants had a higher antioxidant capacity than did non-transgenic control plants. Taken together, RsMYB1 is an actively positive regulator for anthocyanins biosynthesis in radish plants and it might be one of the best targets for anthocyanin production by single gene

  6. In situ localization of phenylpropanoid biosynthetic mRNAs and proteins in Parsley (Petroselinum crispum)

    International Nuclear Information System (INIS)

    Reinold, S.; Hahlbrock, K.

    1997-01-01

    Using in situ RNA/RNA hybridization, enzyme immunolocalization, and histochemical techniques, several phenylpropanoid biosynthetic activities and products were localized in tissue sections from various aerial parts of parsley (Petroselinum crispum) plants at different developmental stages. The enzymes and corresponding mRNAs analyzed included two representatives of general phenylpropanoid metabolism: phenylalanine ammonia-lyase (PAL) and 4-coumarate: CoA ligase (4CL), and one representative each from two distinct branch pathways: chalcone synthase (CHS; flavonoids) and S-adenosyl-L-methionine: bergaptol O-methyltransferase (BMT; furanocoumarins). In almost all cases, the relative timing of accumulation differed greatly for mRNA and protein and indicated short expression periods and short half-lives for all mRNAs as compared to the proteins. PAL and 4CL occurred almost ubiquitously in cell type-specific patterns, and their mRNAs and proteins were always coordinately expressed, whereas the cell type-specific localization of flavonoid and furanocoumarin biosynthetic activities was to a large extent mutually exclusive. However, the distribution patterns of CHS and BMT, when superimposed, closely matched those of PAL and 4CL in nearly all tissues analysed, suggesting that the flavonoid and furanocoumarin pathways together constituted a large majority of the total phenylpropanoid biosynthetic activity. Differential sites of synthesis and accumulation indicating intercellular translocation were observed both for flavonoids and for furanocoumarins in oil ducts and the surrounding tissue. The widespread occurrence of both classes of compounds, as well as selected, pathway-specific mRNAs and enzymes, in many cell types of all parsley organs including various flower parts suggests additional functions beyond the previously established roles of flavonoids in UV protection and furanocoumarins in pathogen defence. (author)

  7. Functional Reconstitution of a Fungal Natural Product Gene Cluster by Advanced Genome Editing

    DEFF Research Database (Denmark)

    Weber, Jakob; Valiante, Vito; Nødvig, Christina Spuur

    2017-01-01

    is not produced among different isolates. Combining computational analysis with targeted gene editing, we could link a single nucleotide insertion in the polyketide synthase of the trypacidin biosynthetic pathway and reconstitute its production in a nonproducing strain. Thus, we present a CRISPR/Cas9-based tool...... for advanced molecular genetic studies in filamentous fungi, exploiting selectable markers separated from the edited locus....

  8. Weighted gene co-expression network analysis of expression data of monozygotic twins identifies specific modules and hub genes related to BMI

    DEFF Research Database (Denmark)

    Wang, Weijing; Jiang, Wenjie; Hou, Lin

    2017-01-01

    BACKGROUND: The therapeutic management of obesity is challenging, hence further elucidating the underlying mechanisms of obesity development and identifying new diagnostic biomarkers and therapeutic targets are urgent and necessary. Here, we performed differential gene expression analysis......) were with a trend of up-regulation in twins with higher BMI when compared to their siblings. Categories of positive regulation of nitric-oxide synthase biosynthetic process, positive regulation of NF-kappa B import into nucleus, and peroxidase activity were significantly enriched within GO database...

  9. Effect of terbinafine on the biosynthetic pathway of isoprenoid compounds in carrot suspension cultured cells.

    Science.gov (United States)

    Miras-Moreno, Begoña; Almagro, Lorena; Pedreño, María Angeles; Sabater-Jara, Ana Belén

    2018-04-21

    Terbinafine induced a significant increase of squalene production. Terbinafine increased the expression levels of squalene synthase. Cyclodextrins did not work as elicitors due to the gene expression levels obtained. Plant sterols are essential components of membrane lipids, which contributing to their fluidity and permeability. Besides their cholesterol-lowering properties, they also have anti-inflammatory, antidiabetic and anticancer activities. Squalene, which is phytosterol precursor, is widely used in medicine, foods and cosmetics due to its anti-tumor, antioxidant and anti-aging activities. Nowadays, vegetable oils constitute the main sources of phytosterols and squalene, but their isolation and purification involve complex extraction protocols and high costs. In this work, Daucus carota cell cultures were used to evaluate the effect of cyclodextrins and terbinafine on the production and accumulation of squalene and phytosterols as well as the expression levels of squalene synthase and cycloartenol synthase genes. D. carota cell cultures were able to produce high levels of extracellular being phytosterols in the presence of cyclodextrins (12 mg/L), these compounds able to increase both the secretion and accumulation of phytosterols in the culture medium. Moreover, terbinafine induced a significant increase in intracellular squalene production, as seen after 168 h of treatment (497.0 ± 23.5 µg g dry weight -1 ) while its extracellular production only increased in the presence of cyclodextrins.The analysis of sqs and cas gene expression revealed that cyclodextrins did not induce genes encoding enzymes involved in the phytosterol biosynthetic pathway since the expression levels of sqs and cas genes in cyclodextrin-treated cells were lower than in control cells. The results, therefore, suggest that cyclodextrins were only able to release phytosterols from the cells to the extracellular medium, thus contributing to their acumulation. To sum up, D. carota

  10. CAR gene cluster and transcript levels of carotenogenic genes in Rhodotorula mucilaginosa.

    Science.gov (United States)

    Landolfo, Sara; Ianiri, Giuseppe; Camiolo, Salvatore; Porceddu, Andrea; Mulas, Giuliana; Chessa, Rossella; Zara, Giacomo; Mannazzu, Ilaria

    2018-01-01

    A molecular approach was applied to the study of the carotenoid biosynthetic pathway of Rhodotorula mucilaginosa. At first, functional annotation of the genome of R. mucilaginosa C2.5t1 was carried out and gene ontology categories were assigned to 4033 predicted proteins. Then, a set of genes involved in different steps of carotenogenesis was identified and those coding for phytoene desaturase, phytoene synthase/lycopene cyclase and carotenoid dioxygenase (CAR genes) proved to be clustered within a region of ~10 kb. Quantitative PCR of the genes involved in carotenoid biosynthesis showed that genes coding for 3-hydroxy-3-methylglutharyl-CoA reductase and mevalonate kinase are induced during exponential phase while no clear trend of induction was observed for phytoene synthase/lycopene cyclase and phytoene dehydrogenase encoding genes. Thus, in R. mucilaginosa the induction of genes involved in the early steps of carotenoid biosynthesis is transient and accompanies the onset of carotenoid production, while that of CAR genes does not correlate with the amount of carotenoids produced. The transcript levels of genes coding for carotenoid dioxygenase, superoxide dismutase and catalase A increased during the accumulation of carotenoids, thus suggesting the activation of a mechanism aimed at the protection of cell structures from oxidative stress during carotenoid biosynthesis. The data presented herein, besides being suitable for the elucidation of the mechanisms that underlie carotenoid biosynthesis, will contribute to boosting the biotechnological potential of this yeast by improving the outcome of further research efforts aimed at also exploring other features of interest.

  11. Transcriptomic analysis reveals key genes related to betalain biosynthesis in pulp coloration of Hylocereus polyrhizus

    Directory of Open Access Journals (Sweden)

    Hua eQingzhu

    2016-01-01

    Full Text Available Betalains have high nutritional value and bioactivities. Red pulp pitaya (Hylocereus polyrhizus is the only fruit containing abundant betalains for consumer. However, no information is available about genes involved in betalain biosynthesis in H. polyrhizus. Herein, two cDNA libraries of pitaya pulps with two different coloration stages (white and red pulp stages of Guanhuahong (H. polyrhizus were constructed. A total of about 12 Gb raw RNA-Seq data was generated and was de novo assembled into 122,677 transcripts with an average length of 1,183 bp and an N50 value of 2008. Approximately 99.99% of all transcripts were annotated based on seven public databases. A total of 8,871 transcripts were significantly regulated. Thirty-three candidate transcripts related to betalain biosynthesis were obtained from the transcriptome data. Transcripts encoding enzymes involved in betalain biosynthesis were analyzed using RT-qPCR at the whole pulp coloration stages of H. Polyrhizus (7-1 and H. Undatus (132-4. Nine key transcripts of betalain biosynthesis were identified. They were assigned to four kinds of genes in betalain biosynthetic pathway, including tyrosinase, 4, 5-DOPA dioxygenase extradiol, cytochrome P450 and glucosyltransferase. Ultimately, a preliminary betalain biosynthetic pathway for pitaya was proposed based on betalain analyses and gene expression profiles.

  12. Metabolic profiling of alternative NAD biosynthetic routes in mouse tissues.

    Directory of Open Access Journals (Sweden)

    Valerio Mori

    Full Text Available NAD plays essential redox and non-redox roles in cell biology. In mammals, its de novo and recycling biosynthetic pathways encompass two independent branches, the "amidated" and "deamidated" routes. Here we focused on the indispensable enzymes gating these two routes, i.e. nicotinamide mononucleotide adenylyltransferase (NMNAT, which in mammals comprises three distinct isozymes, and NAD synthetase (NADS. First, we measured the in vitro activity of the enzymes, and the levels of all their substrates and products in a number of tissues from the C57BL/6 mouse. Second, from these data, we derived in vivo estimates of enzymes'rates and quantitative contributions to NAD homeostasis. The NMNAT activity, mainly represented by nuclear NMNAT1, appears to be high and nonrate-limiting in all examined tissues, except in blood. The NADS activity, however, appears rate-limiting in lung and skeletal muscle, where its undetectable levels parallel a relative accumulation of the enzyme's substrate NaAD (nicotinic acid adenine dinucleotide. In all tissues, the amidated NAD route was predominant, displaying highest rates in liver and kidney, and lowest in blood. In contrast, the minor deamidated route showed higher relative proportions in blood and small intestine, and higher absolute values in liver and small intestine. Such results provide the first comprehensive picture of the balance of the two alternative NAD biosynthetic routes in different mammalian tissues under physiological conditions. This fills a gap in the current knowledge of NAD biosynthesis, and provides a crucial information for the study of NAD metabolism and its role in disease.

  13. plantiSMASH: automated identification, annotation and expression analysis of plant biosynthetic gene clusters

    DEFF Research Database (Denmark)

    Kautsar, Satria A.; Suarez Duran, Hernando G.; Blin, Kai

    2017-01-01

    exploration of the nature and dynamics of gene clustering in plant metabolism. Moreover, spurred by the continuing decrease in costs of plant genome sequencing, they will allow genome mining technologies to be applied to plant natural product discovery. The plantiSMASH web server, precalculated results...

  14. Molecular Link between Leaf Coloration and Gene Expression of Flavonoid and Carotenoid Biosynthesis in Camellia sinensis Cultivar ‘Huangjinya’

    Directory of Open Access Journals (Sweden)

    Lubin Song

    2017-05-01

    Full Text Available ‘Huangjinya’ is an excellent albino tea germplasm cultivated in China because of its bright color and high amino acid content. It is light sensitive, with yellow leaves under intense light while green leaves under weak light. As well, the flavonoid and carotenoid levels increased after moderate shading treatment. However, the mechanism underlying this interesting phenomenon remains unclear. In this study, the transcriptome of ‘Huangjinya’ plants exposed to sunlight and shade were analyzed by high-throughput sequencing followed by de novo assembly. Shading ‘Huangjinya’ made its leaf color turn green. De novo assembly showed that the transcriptome of ‘Huangjinya’ leaves comprises of 127,253 unigenes, with an average length of 914 nt. Among the 81,128 functionally annotated unigenes, 207 differentially expressed genes were identified, including 110 up-regulated and 97 down-regulated genes under moderate shading compared to full light. Gene ontology (GO indicated that the differentially expressed genes are mainly involved in protein and ion binding and oxidoreductase activity. Antioxidation-related pathways, including flavonoid and carotenoid biosynthesis, were highly enriched in these functions. Shading inhibited the expression of flavonoid biosynthesis-associated genes and induced carotenoid biosynthesis-related genes. This would suggest that decreased flavonoid biosynthetic gene expression coincides with increased flavonoids (e.g., catechin content upon moderate shading, while carotenoid levels and biosynthetic gene expression are positively correlated in ‘Huangjinya.’ In conclusion, the leaf color changes in ‘Huangjinya’ are largely determined by the combined effects of flavonoid and carotenoid biosynthesis.

  15. A role for gene duplication and natural variation of gene expression in the evolution of metabolism.

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    Daniel J Kliebenstein

    Full Text Available BACKGROUND: Most eukaryotic genomes have undergone whole genome duplications during their evolutionary history. Recent studies have shown that the function of these duplicated genes can diverge from the ancestral gene via neo- or sub-functionalization within single genotypes. An additional possibility is that gene duplicates may also undergo partitioning of function among different genotypes of a species leading to genetic differentiation. Finally, the ability of gene duplicates to diverge may be limited by their biological function. METHODOLOGY/PRINCIPAL FINDINGS: To test these hypotheses, I estimated the impact of gene duplication and metabolic function upon intraspecific gene expression variation of segmental and tandem duplicated genes within Arabidopsis thaliana. In all instances, the younger tandem duplicated genes showed higher intraspecific gene expression variation than the average Arabidopsis gene. Surprisingly, the older segmental duplicates also showed evidence of elevated intraspecific gene expression variation albeit typically lower than for the tandem duplicates. The specific biological function of the gene as defined by metabolic pathway also modulated the level of intraspecific gene expression variation. The major energy metabolism and biosynthetic pathways showed decreased variation, suggesting that they are constrained in their ability to accumulate gene expression variation. In contrast, a major herbivory defense pathway showed significantly elevated intraspecific variation suggesting that it may be under pressure to maintain and/or generate diversity in response to fluctuating insect herbivory pressures. CONCLUSION: These data show that intraspecific variation in gene expression is facilitated by an interaction of gene duplication and biological activity. Further, this plays a role in controlling diversity of plant metabolism.

  16. Mapping a candidate gene (MdMYB10 for red flesh and foliage colour in apple

    Directory of Open Access Journals (Sweden)

    Allan Andrew C

    2007-07-01

    Full Text Available Abstract Background Integrating plant genomics and classical breeding is a challenge for both plant breeders and molecular biologists. Marker-assisted selection (MAS is a tool that can be used to accelerate the development of novel apple varieties such as cultivars that have fruit with anthocyanin through to the core. In addition, determining the inheritance of novel alleles, such as the one responsible for red flesh, adds to our understanding of allelic variation. Our goal was to map candidate anthocyanin biosynthetic and regulatory genes in a population segregating for the red flesh phenotypes. Results We have identified the Rni locus, a major genetic determinant of the red foliage and red colour in the core of apple fruit. In a population segregating for the red flesh and foliage phenotype we have determined the inheritance of the Rni locus and DNA polymorphisms of candidate anthocyanin biosynthetic and regulatory genes. Simple Sequence Repeats (SSRs and Single Nucleotide Polymorphisms (SNPs in the candidate genes were also located on an apple genetic map. We have shown that the MdMYB10 gene co-segregates with the Rni locus and is on Linkage Group (LG 09 of the apple genome. Conclusion We have performed candidate gene mapping in a fruit tree crop and have provided genetic evidence that red colouration in the fruit core as well as red foliage are both controlled by a single locus named Rni. We have shown that the transcription factor MdMYB10 may be the gene underlying Rni as there were no recombinants between the marker for this gene and the red phenotype in a population of 516 individuals. Associating markers derived from candidate genes with a desirable phenotypic trait has demonstrated the application of genomic tools in a breeding programme of a horticultural crop species.

  17. Extending the biosynthetic repertoires of cyanobacteria and chloroplasts

    DEFF Research Database (Denmark)

    Nielsen, Agnieszka Janina Zygadlo; Mellor, Silas Busck; Vavitsas, Konstantinos

    2016-01-01

    The chloroplasts found in plants and algae, and photosynthetic microorganisms such as cyanobacteria, are emerging hosts for sustainable production of valuable biochemicals, using only inorganic nutrients, water, CO2 and light as inputs. In the past decade, many bioengineering efforts have focused...... on metabolic engineering and synthetic biology in the chloroplast or in cyanobacteria for the production of fuels, chemicals, as well as complex, high-value bioactive molecules. Biosynthesis of all these compounds can be performed in photosynthetic organelles/organisms by heterologous expression...... of chloroplasts and cyanobacteria as biosynthetic compartments and hosts, and we estimate the production levels to be expected from photosynthetic hosts in light of the fraction of electrons and carbon that can potentially be diverted from photosynthesis. The supply of reducing power, in the form of electrons...

  18. Expanding the Bioactive Chemical Space of Anthrabenzoxocinones through Engineering the Highly Promiscuous Biosynthetic Modification Steps.

    Science.gov (United States)

    Mei, Xianyi; Yan, Xiaoli; Zhang, Hui; Yu, Mingjia; Shen, Guangqing; Zhou, Linjun; Deng, Zixin; Lei, Chun; Qu, Xudong

    2018-01-19

    Anthrabenzoxocinones (ABXs) including (-)-ABXs and (+)-ABXs are a group of bacterial FabF-specific inhibitors with potent antimicrobial activity of resistant strains. Optimization of their chemical structures is a promising method to develop potent antibiotics. Through biosynthetic investigation, we herein identified and characterized two highly promiscuous enzymes involved in the (-)-ABX structural modification. The promiscuous halogenase and methyltransferase can respectively introduce halogen-modifications into various positions of the ABX scaffolds and methylation to highly diverse substrates. Manipulation of their activity in both of the (-)-ABXs and (+)-ABXs biosyntheses led to the generation of 14 novel ABX analogues of both enantiomers. Bioactivity assessment revealed that a few of the analogues showed significantly improved antimicrobial activity, with the C3-hydroxyl and chlorine substitutions critical for their activity. This study enormously expands the bioactive chemical space of the ABX family and FabF-specific inhibitors. The disclosed broad-selective biosynthetic machineries and structure-activity relationship provide a solid basis for further generation of potent antimicrobial agents.

  19. Unravelling Protein-Protein Interaction Networks Linked to Aliphatic and Indole Glucosinolate Biosynthetic Pathways in Arabidopsis

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    Sebastian J. Nintemann

    2017-11-01

    Full Text Available Within the cell, biosynthetic pathways are embedded in protein-protein interaction networks. In Arabidopsis, the biosynthetic pathways of aliphatic and indole glucosinolate defense compounds are well-characterized. However, little is known about the spatial orchestration of these enzymes and their interplay with the cellular environment. To address these aspects, we applied two complementary, untargeted approaches—split-ubiquitin yeast 2-hybrid and co-immunoprecipitation screens—to identify proteins interacting with CYP83A1 and CYP83B1, two homologous enzymes specific for aliphatic and indole glucosinolate biosynthesis, respectively. Our analyses reveal distinct functional networks with substantial interconnection among the identified interactors for both pathway-specific markers, and add to our knowledge about how biochemical pathways are connected to cellular processes. Specifically, a group of protein interactors involved in cell death and the hypersensitive response provides a potential link between the glucosinolate defense compounds and defense against biotrophic pathogens, mediated by protein-protein interactions.

  20. An Improved in Vivo Deuterium Labeling Method for Measuring the Biosynthetic Rate of Cytokinins

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    Petr Tarkowski

    2010-12-01

    Full Text Available An improved method for determining the relative biosynthetic rate of isoprenoid cytokinins has been developed. A set of 11 relevant isoprenoid cytokinins, including zeatin isomers, was separated by ultra performance liquid chromatography in less than 6 min. The iP-type cytokinins were observed to give rise to a previously-unknown fragment at m/z 69; we suggest that the diagnostic (204-69 transition can be used to monitor the biosynthetic rate of isopentenyladenine. Furthermore, we found that by treating the cytokinin nucleotides with alkaline phosphatase prior to analysis, the sensitivity of the detection process could be increased. In addition, derivatization (propionylation improved the ESI-MS response by increasing the analytes' hydrophobicity. Indeed, the ESI-MS response of propionylated isopentenyladenosine was about 34% higher than that of its underivatized counterpart. Moreover, the response of the derivatized zeatin ribosides was about 75% higher than that of underivatized zeatin ribosides. Finally, we created a web-based calculator (IZOTOP that facilitates MS/MS data processing and offer it freely to the research community.

  1. Heterologous reconstitution of the intact geodin gene cluster in Aspergillus nidulans through a simple and versatile PCR based approach.

    Directory of Open Access Journals (Sweden)

    Morten Thrane Nielsen

    Full Text Available Fungal natural products are a rich resource for bioactive molecules. To fully exploit this potential it is necessary to link genes to metabolites. Genetic information for numerous putative biosynthetic pathways has become available in recent years through genome sequencing. However, the lack of solid methodology for genetic manipulation of most species severely hampers pathway characterization. Here we present a simple PCR based approach for heterologous reconstitution of intact gene clusters. Specifically, the putative gene cluster responsible for geodin production from Aspergillus terreus was transferred in a two step procedure to an expression platform in A. nidulans. The individual cluster fragments were generated by PCR and assembled via efficient USER fusion prior to transformation and integration via re-iterative gene targeting. A total of 13 open reading frames contained in 25 kb of DNA were successfully transferred between the two species enabling geodin synthesis in A. nidulans. Subsequently, functions of three genes in the cluster were validated by genetic and chemical analyses. Specifically, ATEG_08451 (gedC encodes a polyketide synthase, ATEG_08453 (gedR encodes a transcription factor responsible for activation of the geodin gene cluster and ATEG_08460 (gedL encodes a halogenase that catalyzes conversion of sulochrin to dihydrogeodin. We expect that our approach for transferring intact biosynthetic pathways to a fungus with a well developed genetic toolbox will be instrumental in characterizing the many exciting pathways for secondary metabolite production that are currently being uncovered by the fungal genome sequencing projects.

  2. Genome-Wide Analysis of Secondary Metabolite Gene Clusters in Ophiostoma ulmi and Ophiostoma novo-ulmi Reveals a Fujikurin-Like Gene Cluster with a Putative Role in Infection

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    Nicolau Sbaraini

    2017-06-01

    Full Text Available The emergence of new microbial pathogens can result in destructive outbreaks, since their hosts have limited resistance and pathogens may be excessively aggressive. Described as the major ecological incident of the twentieth century, Dutch elm disease, caused by ascomycete fungi from the Ophiostoma genus, has caused a significant decline in elm tree populations (Ulmus sp. in North America and Europe. Genome sequencing of the two main causative agents of Dutch elm disease (Ophiostoma ulmi and Ophiostoma novo-ulmi, along with closely related species with different lifestyles, allows for unique comparisons to be made to identify how pathogens and virulence determinants have emerged. Among several established virulence determinants, secondary metabolites (SMs have been suggested to play significant roles during phytopathogen infection. Interestingly, the secondary metabolism of Dutch elm pathogens remains almost unexplored, and little is known about how SM biosynthetic genes are organized in these species. To better understand the metabolic potential of O. ulmi and O. novo-ulmi, we performed a deep survey and description of SM biosynthetic gene clusters (BGCs in these species and assessed their conservation among eight species from the Ophiostomataceae family. Among 19 identified BGCs, a fujikurin-like gene cluster (OpPKS8 was unique to Dutch elm pathogens. Phylogenetic analysis revealed that orthologs for this gene cluster are widespread among phytopathogens and plant-associated fungi, suggesting that OpPKS8 may have been horizontally acquired by the Ophiostoma genus. Moreover, the detailed identification of several BGCs paves the way for future in-depth research and supports the potential impact of secondary metabolism on Ophiostoma genus’ lifestyle.

  3. Genes encoding enzymes of the lignin biosynthesis pathway in Eucalyptus

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    Ricardo Harakava

    2005-01-01

    Full Text Available Eucalyptus ESTs libraries were screened for genes involved in lignin biosynthesis. This search was performed under the perspective of recent revisions on the monolignols biosynthetic pathway. Eucalyptus orthologues of all genes of the phenylpropanoid pathway leading to lignin biosynthesis reported in other plant species were identified. A library made with mRNAs extracted from wood was enriched for genes involved in lignin biosynthesis and allowed to infer the isoforms of each gene family that play a major role in wood lignin formation. Analysis of the wood library suggests that, besides the enzymes of the phenylpropanoids pathway, chitinases, laccases, and dirigent proteins are also important for lignification. Colocalization of several enzymes on the endoplasmic reticulum membrane, as predicted by amino acid sequence analysis, supports the existence of metabolic channeling in the phenylpropanoid pathway. This study establishes a framework for future investigations on gene expression level, protein expression and enzymatic assays, sequence polymorphisms, and genetic engineering.

  4. Evolutionary Diversification of Alanine Transaminases in Yeast: Catabolic Specialization and Biosynthetic Redundancy

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    Ximena Escalera-Fanjul

    2017-06-01

    Full Text Available Gene duplication is one of the major evolutionary mechanisms providing raw material for the generation of genes with new or modified functions. The yeast Saccharomyces cerevisiae originated after an allopolyploidization event, which involved mating between two different ancestral yeast species. ScALT1 and ScALT2 codify proteins with 65% identity, which were proposed to be paralogous alanine transaminases. Further analysis of their physiological role showed that while ScALT1 encodes an alanine transaminase which constitutes the main pathway for alanine biosynthesis and the sole pathway for alanine catabolism, ScAlt2 does not display alanine transaminase activity and is not involved in alanine metabolism. Moreover, phylogenetic studies have suggested that ScALT1 and ScALT2 come from each one of the two parental strains which gave rise to the ancestral hybrid. The present work has been aimed to the understanding of the properties of the ancestral type Lacchancea kluyveri LkALT1 and Kluyveromyces lactis KlALT1, alanine transaminases in order to better understand the ScALT1 and ScALT2 evolutionary history. These ancestral -type species were chosen since they harbor ALT1 genes, which are related to ScALT2. Presented results show that, although LkALT1 and KlALT1 constitute ScALT1 orthologous genes, encoding alanine transaminases, both yeasts display LkAlt1 and KlAlt1 independent alanine transaminase activity and additional unidentified alanine biosynthetic and catabolic pathway(s. Furthermore, phenotypic analysis of null mutants uncovered the fact that KlAlt1 and LkAlt1 have an additional role, not related to alanine metabolism but is necessary to achieve wild type growth rate. Our study shows that the ancestral alanine transaminase function has been retained by the ScALT1 encoded enzyme, which has specialized its catabolic character, while losing the alanine independent role observed in the ancestral type enzymes. The fact that ScAlt2 conserves 64

  5. Genes affecting novel seed constituents in Limnanthes alba Benth: transcriptome analysis of developing embryos and a new genetic map of meadowfoam

    Directory of Open Access Journals (Sweden)

    Mary B. Slabaugh

    2015-05-01

    Full Text Available The seed oil of meadowfoam, a new crop in the Limnanthaceae family, is highly enriched in very long chain fatty acids that are desaturated at the Δ5 position. The unusual oil is desirable for cosmetics and innovative industrial applications and the seed meal remaining after oil extraction contains glucolimnanthin, a methoxylated benzylglucosinolate whose degradation products are herbicidal and anti-microbial. Here we describe EST analysis of the developing seed transcriptome that identified major genes involved in biosynthesis and assembly of the seed oil and in glucosinolate metabolic pathways. mRNAs encoding acyl-CoA Δ5 desaturase were notably abundant. The library was searched for simple sequence repeats (SSRs and single nucleotide polymorphisms (SNPs. Fifty-four new SSR markers and eight candidate gene markers were developed and combined with previously developed SSRs to construct a new genetic map for Limnanthes alba. Mapped genes in the lipid biosynthetic pathway encode 3-ketoacyl-CoA synthase (KCS, Δ5 desaturase (Δ5DS, lysophosphatidylacyl-acyl transferase (LPAT, and acyl-CoA diacylglycerol acyl transferase (DGAT. Mapped genes in glucosinolate biosynthetic and degradation pathways encode CYP79A, myrosinase (TGG, and epithiospecifier modifier protein (ESM. The resources developed in this study will further the domestication and improvement of meadowfoam as an oilseed crop.

  6. Identification, Characterization and Expression Analysis of Cell Wall Related Genes in Sorghum bicolor (L. Moench, a Food, Fodder and Biofuel Crop

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    KRISHAN MOHAN RAI

    2016-08-01

    Full Text Available Biomass based alternative fuels offer a solution to the world’s ever-increasing energy demand. With the ability to produce high biomass in marginal lands with low inputs, sorghum has a great potential to meet second-generation biofuel needs. Despite the sorghum crop importance in biofuel and fodder industry, there is no comprehensive information available on the cell wall related genes and gene families (biosynthetic and modification. It is important to identify the cell wall related genes to understand the cell wall biosynthetic process as well as to facilitate biomass manipulation. Genome-wide analysis using gene family specific Hidden Markov Model of conserved domains identified 520 genes distributed among 20 gene families related to biosynthesis/modification of various cell wall polymers such as cellulose, hemicellulose, pectin and lignin. Chromosomal localization analysis of these genes revealed that about 65% of cell wall related genes were confined to four chromosomes (Chr. 1-4. Further, 53 tandem duplication events involving 146 genes were identified in these gene families which could be associated with expansion of genes within families in sorghum. Additionally, we also identified 137 Simple Sequence Repeats related to 112 genes and target sites for 10 miRNAs in some important families such as cellulose synthase, cellulose synthase-like and laccases, etc. To gain further insight into potential functional roles, expression analysis of these gene families was performed using publicly available data sets in various tissues and under abiotic stress conditions. Expression analysis showed tissue specificity as well as differential expression under abiotic stress conditions. Overall, our study provides a comprehensive information on cell wall related genes families in sorghum which offers a valuable resource to develop strategies for altering biomass composition by plant breeding and genetic engineering approaches.

  7. The heme biosynthetic pathway of the obligate Wolbachia endosymbiont of Brugia malayi as a potential anti-filarial drug target.

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    Bo Wu

    2009-07-01

    Full Text Available Filarial parasites (e.g., Brugia malayi, Onchocerca volvulus, and Wuchereria bancrofti are causative agents of lymphatic filariasis and onchocerciasis, which are among the most disabling of neglected tropical diseases. There is an urgent need to develop macro-filaricidal drugs, as current anti-filarial chemotherapy (e.g., diethylcarbamazine [DEC], ivermectin and albendazole can interrupt transmission predominantly by killing microfilariae (mf larvae, but is less effective on adult worms, which can live for decades in the human host. All medically relevant human filarial parasites appear to contain an obligate endosymbiotic bacterium, Wolbachia. This alpha-proteobacterial mutualist has been recognized as a potential target for filarial nematode life cycle intervention, as antibiotic treatments of filarial worms harboring Wolbachia result in the loss of worm fertility and viability upon antibiotic treatments both in vitro and in vivo. Human trials have confirmed this approach, although the length of treatments, high doses required and medical counter-indications for young children and pregnant women warrant the identification of additional anti-Wolbachia drugs.Genome sequence analysis indicated that enzymes involved in heme biosynthesis might constitute a potential anti-Wolbachia target set. We tested different heme biosynthetic pathway inhibitors in ex vivo B. malayi viability assays and report a specific effect of N-methyl mesoporphyrin (NMMP, which targets ferrochelatase (FC, the last step. Our phylogenetic analysis indicates evolutionarily significant divergence between Wolbachia heme genes and their human homologues. We therefore undertook the cloning, overexpression and analysis of several enzymes of this pathway alongside their human homologues, and prepared proteins for drug targeting. In vitro enzyme assays revealed a approximately 600-fold difference in drug sensitivities to succinyl acetone (SA between Wolbachia and human 5

  8. An improved in vivo deuterium labeling method for measuring the biosynthetic rate of cytokinins

    Czech Academy of Sciences Publication Activity Database

    Tarkowski, Petr; Floková, K.; Václavíková, Kateřina; Jaworek, P.; Raus, M.; Nordström, A.; Novák, Ondřej; Doležal, Karel; Šebela, M.; Frébortová, Jitka

    2010-01-01

    Roč. 15, č. 12 (2010), s. 9214-9229 ISSN 1420-3049 R&D Projects: GA ČR(CZ) GA522/08/0920; GA MŠk ED0017/01/01; GA ČR GA301/08/1649 Institutional research plan: CEZ:AV0Z50380511 Keywords : cytokinin * deuterium labelling * biosynthetic rate Subject RIV: CE - Biochemistry Impact factor: 1.988, year: 2010

  9. Silybin content and overexpression of chalcone synthase genes in Silybum marianum L. plants under abiotic elicitation.

    Science.gov (United States)

    El-Garhy, Hoda A S; Khattab, Salah; Moustafa, Mahmoud M A; Abou Ali, Rania; Abdel Azeiz, Ahmed Z; Elhalwagi, Abeer; El Sherif, Fadia

    2016-11-01

    Silymarin, a Silybum marianum seed extract containing a mixture of flavonolignans including silybin, is being used as an antihepatotoxic therapy for liver diseases. In this study, the enhancing effect of gamma irradiation on plant growth parameters of S. marianum under salt stress was investigated. The effect of gamma irradiation, either as a single elicitor or coupled with salinity, on chalcone synthase (CHS) gene expression and silybin A + B yield was also evaluated. The silybin A + B content in S. marianum fruits was estimated by liquid chromatography-mass spectrometry (LC-MS/MS). An increase in silybin content was accompanied by up-regulation of the CHS1, CHS2 and CHS3 genes, which are involved in the silybin biosynthetic pathway. The highest silybin A + B production (0.77 g/100 g plant DW) and transcript levels of the three studied genes (100.2-, 91.9-, and 24.3-fold increase, respectively) were obtained with 100GY gamma irradiation and 4000 ppm salty water. The CHS2 and CHS3 genes were partially sequenced and submitted to the NCBI database under the accession numbers KT252908.1 and KT252909.1, respectively. Developing new approaches to stimulate silybin biosynthetic pathways could be a useful tool to potentiate the use of plants as renewable resources of medicinal compounds. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Transcription profile data of phorbol esters biosynthetic genes during developmental stages in Jatropha curcas.

    Science.gov (United States)

    Jadid, Nurul; Mardika, Rizal Kharisma; Purwani, Kristanti Indah; Permatasari, Erlyta Vivi; Prasetyowati, Indah; Irawan, Mohammad Isa

    2018-06-01

    Jatropha curcas is currently known as an alternative source for biodiesel production. Beside its high free fatty acid content, J. curcas also contains typical diterpenoid-toxic compounds of Euphorbiaceae plant namely phorbol esters. This article present the transcription profile data of genes involved in the biosynthesis of phorbol esters at different developmental stages of leaves, fruit, and seed in Jatropha curcas . Transcriptional profiles were analyzed using reverse transcription-polymerase chain reaction (RT-PCR). We used two genes including GGPPS (Geranylgeranyl diphospate synthase), which is responsible for the formation of common diterpenoid precursor (GGPP) and CS (Casbene Synthase), which functions in the synthesis of casbene. Meanwhile, J. curcas Actin ( ACT ) was used as internal standard. We demonstrated dynamic of GGPPS and CS expression among different stage of development of leaves, fruit and seed in Jatropha .

  11. The Mediator Complex MED15 Subunit Mediates Activation of Downstream Lipid-Related Genes by the WRINKLED1 Transcription Factor.

    Science.gov (United States)

    Kim, Mi Jung; Jang, In-Cheol; Chua, Nam-Hai

    2016-07-01

    The Mediator complex is known to be a master coordinator of transcription by RNA polymerase II, and this complex is recruited by transcription factors (TFs) to target promoters for gene activation or repression. The plant-specific TF WRINKLED1 (WRI1) activates glycolysis-related and fatty acid biosynthetic genes during embryogenesis. However, no Mediator subunit has yet been identified that mediates WRI1 transcriptional activity. Promoter-β-glucuronidase fusion experiments showed that MEDIATOR15 (MED15) is expressed in the same cells in the embryo as WRI1. We found that the Arabidopsis (Arabidopsis thaliana) MED15 subunit of the Mediator complex interacts directly with WRI1 in the nucleus. Overexpression of MED15 or WRI1 increased transcript levels of WRI1 target genes involved in glycolysis and fatty acid biosynthesis; these genes were down-regulated in wild-type or WRI1-overexpressing plants by silencing of MED15 However, overexpression of MED15 in the wri1 mutant also increased transcript levels of WRI1 target genes, suggesting that MED15 also may act with other TFs to activate downstream lipid-related genes. Chromatin immunoprecipitation assays confirmed the association of MED15 with six WRI1 target gene promoters. Additionally, silencing of MED15 resulted in reduced fatty acid content in seedlings and mature seeds, whereas MED15 overexpression increased fatty acid content in both developmental stages. Similar results were found in wri1 mutant and WRI1 overexpression lines. Together, our results indicate that the WRI1/MED15 complex transcriptionally regulates glycolysis-related and fatty acid biosynthetic genes during embryogenesis. © 2016 American Society of Plant Biologists. All Rights Reserved.

  12. Variation in the Apparent Biosynthetic Fractionation for N-alkane δD Among Terrestrial Plants: Patterns, Mechanisms, and Implications

    Science.gov (United States)

    Johnson, J. E.; Tipple, B. J.; Betancourt, J. L.; Ehleringer, J. R.; Leavitt, S. W.; Monson, R. K.

    2016-12-01

    Long-chain normal alkanes (n-alkanes) are a component of the leaf cuticle of all terrestrial plants. Since the hydrogen in the n-alkanes is derived from the hydrogen in plants' water sources and is non-exchangeable, the stable hydrogen isotopic composition (δD) of the n-alkanes provides information about the δD of environmental waters. While this relationship creates opportunities for using n-alkane δD for process-based reconstructions of δD of environmental waters, progress in this direction is currently constrained by the observation that terrestrial plants exhibit a startlingly wide range of apparent biosynthetic fractionations. To understand the mechanisms responsible for variation in the apparent biosynthetic fractionations, we compared measurements and models of δD for n-C29 in a water-limited ecosystem where the timing of primary and secondary cuticle deposition is closely coupled to water availability (Tumamoc Hill, Tucson, Arizona, USA). During the 2014-2015 hydrologic year, the most widespread and abundant plant species at this site exhibited δD for n-C29 varying over a total range of 102‰. Discrete samples of leaf water collected at the same time as the n-C29 samples exhibited δD varying over a total range of only 53‰, but a continuous model of leaf water through the annual cycle predicted δD varying over a total range of 190‰. These results indicate that the observed variation in the apparent biosynthetic fractionation for n-C29 δD could be primarily attributable to leaf water dynamics that are temporally uncoupled from primary and secondary cuticle deposition. If a single biosynthetic fractionation does describe the relationship between the δD of n-alkanes and leaf water during intervals of cuticle deposition, it will facilitate process-based interpretations of n-alkane δD values in ecological, hydrological, and climatological studies of modern and ancient terrestrial environments.

  13. Examination of triacylglycerol biosynthetic pathways via de novo transcriptomic and proteomic analyses in an unsequenced microalga.

    Directory of Open Access Journals (Sweden)

    Michael T Guarnieri

    Full Text Available Biofuels derived from algal lipids represent an opportunity to dramatically impact the global energy demand for transportation fuels. Systems biology analyses of oleaginous algae could greatly accelerate the commercialization of algal-derived biofuels by elucidating the key components involved in lipid productivity and leading to the initiation of hypothesis-driven strain-improvement strategies. However, higher-level systems biology analyses, such as transcriptomics and proteomics, are highly dependent upon available genomic sequence data, and the lack of these data has hindered the pursuit of such analyses for many oleaginous microalgae. In order to examine the triacylglycerol biosynthetic pathway in the unsequenced oleaginous microalga, Chlorella vulgaris, we have established a strategy with which to bypass the necessity for genomic sequence information by using the transcriptome as a guide. Our results indicate an upregulation of both fatty acid and triacylglycerol biosynthetic machinery under oil-accumulating conditions, and demonstrate the utility of a de novo assembled transcriptome as a search model for proteomic analysis of an unsequenced microalga.

  14. Modulation of guanosine nucleotides biosynthetic pathways enhanced GDP-L-fucose production in recombinant Escherichia coli.

    Science.gov (United States)

    Lee, Won-Heong; Shin, So-Yeon; Kim, Myoung-Dong; Han, Nam Soo; Seo, Jin-Ho

    2012-03-01

    Guanosine 5'-triphosphate (GTP) is the key substrate for biosynthesis of guanosine 5'-diphosphate (GDP)-L-fucose. In this study, improvement of GDP-L-fucose production was attempted by manipulating the biosynthetic pathway for guanosine nucleotides in recombinant Escherichia coli-producing GDP-L-fucose. The effects of overexpression of inosine 5'-monophosphate (IMP) dehydrogenase, guanosine 5'-monophosphate (GMP) synthetase (GuaB and GuaA), GMP reductase (GuaC) and guanosine-inosine kinase (Gsk) on GDP-L-fucose production were investigated in a series of fed-batch fermentations. Among the enzymes tested, overexpression of Gsk led to a significant improvement of GDP-L-fucose production. Maximum GDP-L-fucose concentration of 305.5 ± 5.3 mg l(-1) was obtained in the pH-stat fed-batch fermentation of recombinant E. coli-overexpressing Gsk, which corresponds to a 58% enhancement in the GDP-L-fucose production compared with the control strain overexpressing GDP-L-fucose biosynthetic enzymes. Such an enhancement of GDP-L-fucose production could be due to the increase in the intracellular level of GMP.

  15. In silico exploration of Red Sea Bacillus genomes for natural product biosynthetic gene clusters

    KAUST Repository

    Othoum, Ghofran K; Bougouffa, Salim; Razali, Rozaimi; Bokhari, Ameerah; Alamoudi, Soha; Antunes, André ; Gao, Xin; Hoehndorf, Robert; Arold, Stefan T.; Gojobori, Takashi; Hirt, Heribert; Mijakovic, Ivan; Bajic, Vladimir B.; Lafi, Feras Fawzi; Essack, Magbubah

    2018-01-01

    are better potential sources for novel antibiotics. Moreover, the genome of the Red Sea strain B. paralicheniformis Bac48 is more enriched in modular PKS genes compared to B. licheniformis strains and other B. paralicheniformis strains. This may be linked

  16. Identification of Putative Precursor Genes for the Biosynthesis of Cannabinoid-Like Compound in Radula marginata

    Directory of Open Access Journals (Sweden)

    Tajammul Hussain

    2018-05-01

    Full Text Available The liverwort Radula marginata belongs to the bryophyte division of land plants and is a prospective alternate source of cannabinoid-like compounds. However, mechanistic insights into the molecular pathways directing the synthesis of these cannabinoid-like compounds have been hindered due to the lack of genetic information. This prompted us to do deep sequencing, de novo assembly and annotation of R. marginata transcriptome, which resulted in the identification and validation of the genes for cannabinoid biosynthetic pathway. In total, we have identified 11,421 putative genes encoding 1,554 enzymes from 145 biosynthetic pathways. Interestingly, we have identified all the upstream genes of the central precursor of cannabinoid biosynthesis, cannabigerolic acid (CBGA, including its two first intermediates, stilbene acid (SA and geranyl diphosphate (GPP. Expression of all these genes was validated using quantitative real-time PCR. We have characterized the protein structure of stilbene synthase (STS, which is considered as a homolog of olivetolic acid in R. marginata. Moreover, the metabolomics approach enabled us to identify CBGA-analogous compounds using electrospray ionization mass spectrometry (ESI-MS/MS and gas chromatography mass spectrometry (GC-MS. Transcriptomic analysis revealed 1085 transcription factors (TF from 39 families. Comparative analysis showed that six TF families have been uniquely predicted in R. marginata. In addition, the bioinformatics analysis predicted a large number of simple sequence repeats (SSRs and non-coding RNAs (ncRNAs. Our results collectively provide mechanistic insights into the putative precursor genes for the biosynthesis of cannabinoid-like compounds and a novel transcriptomic resource for R. marginata. The large-scale transcriptomic resource generated in this study would further serve as a reference transcriptome to explore the Radulaceae family.

  17. The Tomato Hoffman's Anthocyaninless Gene Encodes a bHLH Transcription Factor Involved in Anthocyanin Biosynthesis That Is Developmentally Regulated and Induced by Low Temperatures.

    Science.gov (United States)

    Qiu, Zhengkun; Wang, Xiaoxuan; Gao, Jianchang; Guo, Yanmei; Huang, Zejun; Du, Yongchen

    2016-01-01

    Anthocyanin pigments play many roles in plants, including providing protection against biotic and abiotic stresses. Many of the genes that mediate anthocyanin accumulation have been identified through studies of flowers and fruits; however, the mechanisms of genes involved in anthocyanin regulation in seedlings under low-temperature stimulus are less well understood. Genetic characterization of a tomato inbred line, FMTT271, which showed no anthocyanin pigmentation, revealed a mutation in a bHLH transcription factor (TF) gene, which corresponds to the ah (Hoffman's anthocyaninless) locus, and so the gene in FMTT271 at that locus was named ah. Overexpression of the wild type allele of AH in FMTT271 resulted in greater anthocyanin accumulation and increased expression of several genes in the anthocyanin biosynthetic pathway. The expression of AH and anthocyanin accumulation in seedlings was shown to be developmentally regulated and induced by low-temperature stress. Additionally, transcriptome analyses of hypocotyls and leaves from the near-isogenic lines seedlings revealed that AH not only influences the expression of anthocyanin biosynthetic genes, but also genes associated with responses to abiotic stress. Furthermore, the ah mutation was shown to cause accumulation of reactive oxidative species and the constitutive activation of defense responses under cold conditions. These results suggest that AH regulates anthocyanin biosynthesis, thereby playing a protective role, and that this function is particularly important in young seedlings that are particularly vulnerable to abiotic stresses.

  18. The Tomato Hoffman's Anthocyaninless Gene Encodes a bHLH Transcription Factor Involved in Anthocyanin Biosynthesis That Is Developmentally Regulated and Induced by Low Temperatures.

    Directory of Open Access Journals (Sweden)

    Zhengkun Qiu

    Full Text Available Anthocyanin pigments play many roles in plants, including providing protection against biotic and abiotic stresses. Many of the genes that mediate anthocyanin accumulation have been identified through studies of flowers and fruits; however, the mechanisms of genes involved in anthocyanin regulation in seedlings under low-temperature stimulus are less well understood. Genetic characterization of a tomato inbred line, FMTT271, which showed no anthocyanin pigmentation, revealed a mutation in a bHLH transcription factor (TF gene, which corresponds to the ah (Hoffman's anthocyaninless locus, and so the gene in FMTT271 at that locus was named ah. Overexpression of the wild type allele of AH in FMTT271 resulted in greater anthocyanin accumulation and increased expression of several genes in the anthocyanin biosynthetic pathway. The expression of AH and anthocyanin accumulation in seedlings was shown to be developmentally regulated and induced by low-temperature stress. Additionally, transcriptome analyses of hypocotyls and leaves from the near-isogenic lines seedlings revealed that AH not only influences the expression of anthocyanin biosynthetic genes, but also genes associated with responses to abiotic stress. Furthermore, the ah mutation was shown to cause accumulation of reactive oxidative species and the constitutive activation of defense responses under cold conditions. These results suggest that AH regulates anthocyanin biosynthesis, thereby playing a protective role, and that this function is particularly important in young seedlings that are particularly vulnerable to abiotic stresses.

  19. Identification of the First Riboflavin Catabolic Gene Cluster Isolated from Microbacterium maritypicum G10*

    OpenAIRE

    Xu, Hui; Chakrabarty, Yindrila; Philmus, Benjamin; Mehta, Angad P.; Bhandari, Dhananjay; Hohmann, Hans-Peter; Begley, Tadhg P.

    2016-01-01

    Riboflavin is a common cofactor, and its biosynthetic pathway is well characterized. However, its catabolic pathway, despite intriguing hints in a few distinct organisms, has never been established. This article describes the isolation of a Microbacterium maritypicum riboflavin catabolic strain, and the cloning of the riboflavin catabolic genes. RcaA, RcaB, RcaD, and RcaE were overexpressed and biochemically characterized as riboflavin kinase, riboflavin reductase, ribokinase, and riboflavin ...

  20. Expression of eicosanoid biosynthetic and catabolic enzymes in peritoneal endometriosis.

    Science.gov (United States)

    Lousse, J-C; Defrère, S; Colette, S; Van Langendonckt, A; Donnez, J

    2010-03-01

    Increased peritoneal eicosanoid concentrations have been reported in endometriosis patients and might be important in disease-associated pain and inflammation. Here, we evaluated the expression of key biosynthetic and catabolic enzymes involved in this abnormal eicosanoid production in peritoneal macrophages and endometriotic lesions. Peritoneal macrophages, endometriotic lesions and matched eutopic endometrium were collected from endometriosis patients (n = 40). Peritoneal macrophages and eutopic endometrium samples were also collected from disease-free women (n = 25). Expression of type IIA secretory phospholipase A(2) (sPLA(2)-IIA), cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-1 (mPGES-1), 15-hydroxyprostaglandin dehydrogenase (15-PGDH) and 5-lipoxygenase (5-LO) was quantified by real-time PCR, and these five key enzymes were localized by immunohistochemistry. sPLA(2)-IIA, COX-2 and mPGES-1 mRNA was significantly increased in peritoneal macrophages of endometriosis patients compared with controls (P = 0.006, P = 0.016 and P = 0.025, respectively). In endometriosis patients, sPLA(2)-IIA, mPGES-1 and 15-PGDH mRNA was significantly enhanced in peritoneal lesions compared with matched eutopic endometrium (P endometriosis group compared with controls (P = 0.023). Finally, sPLA(2)-IIA, COX-2, mPGES-1 and 15-PGDH immunostaining was found mainly in endometrial glands, whereas 5-LO was distributed throughout the glands and stroma. Our study highlights an imbalance between eicosanoid biosynthesis and degradation in endometriosis patients. Both peritoneal macrophages and endometriotic lesions may be involved. Research into new molecules inhibiting biosynthetic enzymes (such as sPLA(2)-IIA and mPGES-1) and/or activating catabolic enzymes (such as 15-PGDH) may prove to be a major field of investigation in the development of targeted medical therapies.

  1. The mangotoxin biosynthetic operon (mbo) is specifically distributed within Pseudomonas syringae genomospecies 1 and was acquired only once during evolution.

    Science.gov (United States)

    Carrión, Víctor J; Gutiérrez-Barranquero, José A; Arrebola, Eva; Bardaji, Leire; Codina, Juan C; de Vicente, Antonio; Cazorla, Francisco M; Murillo, Jesús

    2013-02-01

    Mangotoxin production was first described in Pseudomonas syringae pv. syringae strains. A phenotypic characterization of 94 P. syringae strains was carried out to determine the genetic evolution of the mangotoxin biosynthetic operon (mbo). We designed a PCR primer pair specific for the mbo operon to examine its distribution within the P. syringae complex. These primers amplified a 692-bp DNA fragment from 52 mangotoxin-producing strains and from 7 non-mangotoxin-producing strains that harbor the mbo operon, whereas 35 non-mangotoxin-producing strains did not yield any amplification. This, together with the analysis of draft genomes, allowed the identification of the mbo operon in five pathovars (pathovars aptata, avellanae, japonica, pisi, and syringae), all of which belong to genomospecies 1, suggesting a limited distribution of the mbo genes in the P. syringae complex. Phylogenetic analyses using partial sequences from housekeeping genes differentiated three groups within genomospecies 1. All of the strains containing the mbo operon clustered in groups I and II, whereas those lacking the operon clustered in group III; however, the relative branching order of these three groups is dependent on the genes used to construct the phylogeny. The mbo operon maintains synteny and is inserted in the same genomic location, with high sequence conservation around the insertion point, for all the strains in groups I and II. These data support the idea that the mbo operon was acquired horizontally and only once by the ancestor of groups I and II from genomospecies 1 within the P. syringae complex.

  2. Accurate prediction of secondary metabolite gene clusters in filamentous fungi

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam; Nielsen, Jakob Blæsbjerg; Klitgaard, Andreas

    2013-01-01

    Biosynthetic pathways of secondary metabolites from fungi are currently subject to an intense effort to elucidate the genetic basis for these compounds due to their large potential within pharmaceutics and synthetic biochemistry. The preferred method is methodical gene deletions to identify...... used A. nidulans for our method development and validation due to the wealth of available biochemical data, but the method can be applied to any fungus with a sequenced and assembled genome, thus supporting further secondary metabolite pathway elucidation in the fungal kingdom....

  3. Distribution of δ-aminolevulinic acid biosynthetic pathways among phototrophic and related bacteria

    International Nuclear Information System (INIS)

    Avissar, Y.J.; Beale, S.I.; Ormerod, J.G.

    1989-01-01

    Two biosynthetic pathways are known for the universal tetrapyrrole precursor, δ-aminolevulinic acid (ALA): condensation of glycine and succinyl-CoA to form ALA with the loss of C-1 of glycine as CO 2 , and conversion of the intact carbon skeleton of glutamate to ALA in a process requiring tRNA Glu , ATP, Mg 2+ , NADPH, and pyridoxal phosphate. The distribution of the two ALA biosynthetic pathways among various bacterial genera was determined, using cell-free extracts obtained from representative organisms. Evidence for the operation of the glutamate pathway was obtained by the measurement of RNase-sensitive label incorporation from glutamate into ALA using 3,4-[ 3 H]glutamate and 1-[ 14 C]glutamate as substrate. The glycine pathway was indicated by RNase-insensitive incorporation of level from 2-[ 14 C]glycine into ALA. The distribution of the two pathways among the bacteria tested was in general agreement with their previously phylogenetic relationships and clearly indicates that the glutamate pathway is the more ancient process, whereas the glycine pathway probably evolved much later. The glutamate pathway is the more widely utilized one among bacteria, while the glycine pathway is apparently limited to the α subgroup of purple bacteria (including Rhodobacter, Rhodospirillum, and Rhizobium). E. coli was found ALA via the glutamate pathway. The ALA-requiring hemA mutant of E. coli was determined to lack the dehydrogenase activity that utilizes glutamyl-tRNA as a substrate

  4. Natural Variation in Synthesis and Catabolism Genes Influences Dhurrin Content in Sorghum

    Directory of Open Access Journals (Sweden)

    Chad M. Hayes

    2015-07-01

    Full Text Available Cyanogenic glucosides are natural compounds found in more than 1000 species of angiosperms that produce HCN and are deemed undesirable for agricultural use. However, these compounds are important components of the primary defensive mechanisms of many plant species. One of the best-studied cyanogenic glucosides is dhurrin [(--hydroxymandelonitrile-β--glucopyranoside], which is produced primarily in sorghum [ (L. Moench]. The biochemical basis for dhurrin metabolism is well established; however, little information is available on its genetic control. Here, we dissect the genetic control of leaf dhurrin content through a genome-wide association study (GWAS using a panel of 700 diverse converted sorghum lines (conversion panel previously subjected to pre-breeding and selected for short stature (∼1 m in height and photoperiod insensitivity. The conversion panel was grown for 2 yr in three environments. Wide variation for leaf dhurrin content was found in the sorghum conversion panel, with the Caudatum group exhibiting the highest dhurrin content and the Guinea group showing the lowest dhurrin content. A GWAS using a mixed linear model revealed significant associations (a false discovery rate [FDR] < 0.05 close to both UGT 185B1 in the canonical biosynthetic gene cluster on chromosome 1 and close to the catabolic dhurrinase loci on chromosome 8. Dhurrin content was associated consistently with biosynthetic genes in the two N-fertilized environments, while dhurrin content was associated with catabolic loci in the environment without supplemental N. These results suggest that genes for both biosynthesis and catabolism are important in determining natural variation for leaf dhurrin in sorghum in different environments.

  5. The rice YABBY1 gene is involved in the feedback regulation of gibberellin metabolism.

    Science.gov (United States)

    Dai, Mingqiu; Zhao, Yu; Ma, Qian; Hu, Yongfeng; Hedden, Peter; Zhang, Qifa; Zhou, Dao-Xiu

    2007-05-01

    Gibberellin (GA) biosynthesis is regulated by feedback control providing a mechanism for GA homeostasis in plants. However, regulatory elements involved in the feedback control are not known. In this report, we show that a rice (Oryza sativa) YABBY1 (YAB1) gene had a similar expression pattern as key rice GA biosynthetic genes GA3ox2 and GA20ox2. Overexpression of YAB1 in transgenic rice resulted in a semidwarf phenotype that could be fully rescued by applied GA. Quantification of the endogenous GA content revealed increases of GA(20) and decreases of GA(1) levels in the overexpression plants, in which the transcripts of the biosynthetic gene GA3ox2 were decreased. Cosuppression of YAB1 in transgenic plants induced expression of GA3ox2. The repression of GA3ox2 could be obtained upon treatment by dexamethasone of transgenic plants expressing a YAB1-glucocorticoid receptor fusion. Importantly, we show that YAB1 bound to a GA-responsive element within the GA3ox2 promoter. In addition, the expression of YAB1 was deregulated in GA biosynthesis and signaling mutants and could be either transiently induced by GA or repressed by a GA inhibitor. Finally, either overexpression or cosuppression of YAB1 impaired GA-mediated repression of GA3ox2. These data together suggest that YAB1 is involved in the feedback regulation of GA biosynthesis in rice.

  6. With a pinch of extra salt-Did predatory protists steal genes from their food?

    Science.gov (United States)

    Czech, Laura; Bremer, Erhard

    2018-02-01

    The cellular adjustment of Bacteria and Archaea to high-salinity habitats is well studied and has generally been classified into one of two strategies. These are to accumulate high levels either of ions (the "salt-in" strategy) or of physiologically compliant organic osmolytes, the compatible solutes (the "salt-out" strategy). Halophilic protists are ecophysiological important inhabitants of salt-stressed ecosystems because they are not only very abundant but also represent the majority of eukaryotic lineages in nature. However, their cellular osmostress responses have been largely neglected. Recent reports have now shed new light on this issue using the geographically widely distributed halophilic heterotrophic protists Halocafeteria seosinensis, Pharyngomonas kirbyi, and Schmidingerothrix salinarum as model systems. Different approaches led to the joint conclusion that these unicellular Eukarya use the salt-out strategy to cope successfully with the persistent high salinity in their habitat. They accumulate various compatible solutes, e.g., glycine betaine, myo-inositol, and ectoines. The finding of intron-containing biosynthetic genes for ectoine and hydroxyectoine, their salt stress-responsive transcription in H. seosinensis, and the production of ectoine and its import by S. salinarum come as a considerable surprise because ectoines have thus far been considered exclusive prokaryotic compatible solutes. Phylogenetic considerations of the ectoine/hydroxyectoine biosynthetic genes of H. seosinensis suggest that they have been acquired via lateral gene transfer by these bacterivorous Eukarya from ectoine/hydroxyectoine-producing food bacteria that populate the same habitat.

  7. With a pinch of extra salt—Did predatory protists steal genes from their food?

    Science.gov (United States)

    Czech, Laura

    2018-01-01

    The cellular adjustment of Bacteria and Archaea to high-salinity habitats is well studied and has generally been classified into one of two strategies. These are to accumulate high levels either of ions (the “salt-in” strategy) or of physiologically compliant organic osmolytes, the compatible solutes (the “salt-out” strategy). Halophilic protists are ecophysiological important inhabitants of salt-stressed ecosystems because they are not only very abundant but also represent the majority of eukaryotic lineages in nature. However, their cellular osmostress responses have been largely neglected. Recent reports have now shed new light on this issue using the geographically widely distributed halophilic heterotrophic protists Halocafeteria seosinensis, Pharyngomonas kirbyi, and Schmidingerothrix salinarum as model systems. Different approaches led to the joint conclusion that these unicellular Eukarya use the salt-out strategy to cope successfully with the persistent high salinity in their habitat. They accumulate various compatible solutes, e.g., glycine betaine, myo-inositol, and ectoines. The finding of intron-containing biosynthetic genes for ectoine and hydroxyectoine, their salt stress–responsive transcription in H. seosinensis, and the production of ectoine and its import by S. salinarum come as a considerable surprise because ectoines have thus far been considered exclusive prokaryotic compatible solutes. Phylogenetic considerations of the ectoine/hydroxyectoine biosynthetic genes of H. seosinensis suggest that they have been acquired via lateral gene transfer by these bacterivorous Eukarya from ectoine/hydroxyectoine-producing food bacteria that populate the same habitat. PMID:29394244

  8. The Tomato Hoffman’s Anthocyaninless Gene Encodes a bHLH Transcription Factor Involved in Anthocyanin Biosynthesis That Is Developmentally Regulated and Induced by Low Temperatures

    Science.gov (United States)

    Gao, Jianchang; Guo, Yanmei; Huang, Zejun; Du, Yongchen

    2016-01-01

    Anthocyanin pigments play many roles in plants, including providing protection against biotic and abiotic stresses. Many of the genes that mediate anthocyanin accumulation have been identified through studies of flowers and fruits; however, the mechanisms of genes involved in anthocyanin regulation in seedlings under low-temperature stimulus are less well understood. Genetic characterization of a tomato inbred line, FMTT271, which showed no anthocyanin pigmentation, revealed a mutation in a bHLH transcription factor (TF) gene, which corresponds to the ah (Hoffman's anthocyaninless) locus, and so the gene in FMTT271 at that locus was named ah. Overexpression of the wild type allele of AH in FMTT271 resulted in greater anthocyanin accumulation and increased expression of several genes in the anthocyanin biosynthetic pathway. The expression of AH and anthocyanin accumulation in seedlings was shown to be developmentally regulated and induced by low-temperature stress. Additionally, transcriptome analyses of hypocotyls and leaves from the near-isogenic lines seedlings revealed that AH not only influences the expression of anthocyanin biosynthetic genes, but also genes associated with responses to abiotic stress. Furthermore, the ah mutation was shown to cause accumulation of reactive oxidative species and the constitutive activation of defense responses under cold conditions. These results suggest that AH regulates anthocyanin biosynthesis, thereby playing a protective role, and that this function is particularly important in young seedlings that are particularly vulnerable to abiotic stresses. PMID:26943362

  9. SANDPUMA: ensemble predictions of nonribosomal peptide chemistry reveal biosynthetic diversity across Actinobacteria.

    Science.gov (United States)

    Chevrette, Marc G; Aicheler, Fabian; Kohlbacher, Oliver; Currie, Cameron R; Medema, Marnix H

    2017-10-15

    Nonribosomally synthesized peptides (NRPs) are natural products with widespread applications in medicine and biotechnology. Many algorithms have been developed to predict the substrate specificities of nonribosomal peptide synthetase adenylation (A) domains from DNA sequences, which enables prioritization and dereplication, and integration with other data types in discovery efforts. However, insufficient training data and a lack of clarity regarding prediction quality have impeded optimal use. Here, we introduce prediCAT, a new phylogenetics-inspired algorithm, which quantitatively estimates the degree of predictability of each A-domain. We then systematically benchmarked all algorithms on a newly gathered, independent test set of 434 A-domain sequences, showing that active-site-motif-based algorithms outperform whole-domain-based methods. Subsequently, we developed SANDPUMA, a powerful ensemble algorithm, based on newly trained versions of all high-performing algorithms, which significantly outperforms individual methods. Finally, we deployed SANDPUMA in a systematic investigation of 7635 Actinobacteria genomes, suggesting that NRP chemical diversity is much higher than previously estimated. SANDPUMA has been integrated into the widely used antiSMASH biosynthetic gene cluster analysis pipeline and is also available as an open-source, standalone tool. SANDPUMA is freely available at https://bitbucket.org/chevrm/sandpuma and as a docker image at https://hub.docker.com/r/chevrm/sandpuma/ under the GNU Public License 3 (GPL3). chevrette@wisc.edu or marnix.medema@wur.nl. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  10. Sampling gene diversity across the supergroup Amoebozoa: large EST data sets from Acanthamoeba castellanii, Hartmannella vermiformis, Physarum polycephalum, Hyperamoeba dachnaya and Hyperamoeba sp.

    Science.gov (United States)

    Watkins, Russell F; Gray, Michael W

    2008-04-01

    From comparative analysis of EST data for five taxa within the eukaryotic supergroup Amoebozoa, including two free-living amoebae (Acanthamoeba castellanii, Hartmannella vermiformis) and three slime molds (Physarum polycephalum, Hyperamoeba dachnaya and Hyperamoeba sp.), we obtained new broad-range perspectives on the evolution and biosynthetic capacity of this assemblage. Together with genome sequences for the amoebozoans Dictyostelium discoideum and Entamoeba histolytica, and including partial genome sequence available for A. castellanii, we used the EST data to identify genes that appear to be exclusive to the supergroup, and to specific clades therein. Many of these genes are likely involved in cell-cell communication or differentiation. In examining on a broad scale a number of characters that previously have been considered in simpler cross-species comparisons, typically between Dictyostelium and Entamoeba, we find that Amoebozoa as a whole exhibits striking variation in the number and distribution of biosynthetic pathways, for example, ones for certain critical stress-response molecules, including trehalose and mannitol. Finally, we report additional compelling cases of lateral gene transfer within Amoebozoa, further emphasizing that although this process has influenced genome evolution in all examined amoebozoan taxa, it has done so to a variable extent.

  11. Optimization of RT-PCR reactions in studies with genes of lignin biosynthetic route in Saccharum spontaneum

    Directory of Open Access Journals (Sweden)

    JUAN P.P. LLERENA

    Full Text Available ABSTRACT Saccharum spontaneum has been used for the development of energy cane a crop aimed to be used for the production of second-generation ethanol, or lignocellulosic ethanol. Lignin is a main challenge in the conversion of cell wall sugars into ethanol. In our studies to isolate the genes the lignin biosynthesis in S. spontaneum we have had great difficulty in RT-PCR reactions. Thus, we evaluated the effectiveness of different additives in the amplification of these genes. While COMT and CCoAOMT genes did not need any additives for other genes there was no amplification (HCT, F5H, 4CL and CCR or the yield was very low (CAD and C4H. The application of supplementary cDNA was enough to overcome the non-specificity and low yield for C4H and C3H, while the addition of 0.04% BSA + 2% formamide was effective to amplify 4CL, CCR, F5H and CCR. HCT was amplified only by addition of 0.04% BSA + 2% formamide + 0.1 M trehalose and amplification of PAL was possible with addition of 2% of DMSO. Besides optimization of expression assays, the results show that additives can act independently or synergistically.

  12. Transcriptome analysis reveals candidate genes involved in luciferin metabolism in Luciola aquatilis (Coleoptera: Lampyridae

    Directory of Open Access Journals (Sweden)

    Wanwipa Vongsangnak

    2016-10-01

    Full Text Available Bioluminescence, which living organisms such as fireflies emit light, has been studied extensively for over half a century. This intriguing reaction, having its origins in nature where glowing insects can signal things such as attraction or defense, is now widely used in biotechnology with applications of bioluminescence and chemiluminescence. Luciferase, a key enzyme in this reaction, has been well characterized; however, the enzymes involved in the biosynthetic pathway of its substrate, luciferin, remains unsolved at present. To elucidate the luciferin metabolism, we performed a de novo transcriptome analysis using larvae of the firefly species, Luciola aquatilis. Here, a comparative analysis is performed with the model coleopteran insect Tribolium casteneum to elucidate the metabolic pathways in L. aquatilis. Based on a template luciferin biosynthetic pathway, combined with a range of protein and pathway databases, and various prediction tools for functional annotation, the candidate genes, enzymes, and biochemical reactions involved in luciferin metabolism are proposed for L. aquatilis. The candidate gene expression is validated in the adult L. aquatilis using reverse transcription PCR (RT-PCR. This study provides useful information on the bio-production of luciferin in the firefly and will benefit to future applications of the valuable firefly bioluminescence system.

  13. Phenotype-gene: 47 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available iency during process named biosynthetic process under influence of raffinose in environment of warm/hot temp...ency during process named biosynthetic process under influence of raffinose in environment of warm/hot tempe

  14. RNA-Seq analysis and annotation of a draft blueberry genome assembly identifies candidate genes involved in fruit ripening, biosynthesis of bioactive compounds, and stage-specific alternative splicing.

    Science.gov (United States)

    Gupta, Vikas; Estrada, April D; Blakley, Ivory; Reid, Rob; Patel, Ketan; Meyer, Mason D; Andersen, Stig Uggerhøj; Brown, Allan F; Lila, Mary Ann; Loraine, Ann E

    2015-01-01

    Blueberries are a rich source of antioxidants and other beneficial compounds that can protect against disease. Identifying genes involved in synthesis of bioactive compounds could enable the breeding of berry varieties with enhanced health benefits. Toward this end, we annotated a previously sequenced draft blueberry genome assembly using RNA-Seq data from five stages of berry fruit development and ripening. Genome-guided assembly of RNA-Seq read alignments combined with output from ab initio gene finders produced around 60,000 gene models, of which more than half were similar to proteins from other species, typically the grape Vitis vinifera. Comparison of gene models to the PlantCyc database of metabolic pathway enzymes identified candidate genes involved in synthesis of bioactive compounds, including bixin, an apocarotenoid with potential disease-fighting properties, and defense-related cyanogenic glycosides, which are toxic. Cyanogenic glycoside (CG) biosynthetic enzymes were highly expressed in green fruit, and a candidate CG detoxification enzyme was up-regulated during fruit ripening. Candidate genes for ethylene, anthocyanin, and 400 other biosynthetic pathways were also identified. Homology-based annotation using Blast2GO and InterPro assigned Gene Ontology terms to around 15,000 genes. RNA-Seq expression profiling showed that blueberry growth, maturation, and ripening involve dynamic gene expression changes, including coordinated up- and down-regulation of metabolic pathway enzymes and transcriptional regulators. Analysis of RNA-seq alignments identified developmentally regulated alternative splicing, promoter use, and 3' end formation. We report genome sequence, gene models, functional annotations, and RNA-Seq expression data that provide an important new resource enabling high throughput studies in blueberry.

  15. Labelled precursors for biosynthetic studies on naphthylisoquinoline alkaloids

    International Nuclear Information System (INIS)

    Bringmann, Gerhard; Pokorny, Frank; Wenzel, Matthias; Wurm, Kathi; Schneider, Christoph

    1997-01-01

    The isotope labelled monocyclic ketones 5 and 8, postulated precursors to the presumably acetogenic naphthylisoquinoline alkaloids, have been synthesized for biogenetic experiments to Ancistrocladaceae and Dioncophyllaceae plants. Key step of the preparation of 1-(2'-[carbonyl- 14 C] acetyl-3',5'-dibenzyloxyphenyl-2-propanone ([ 14 C]-13 is the C-acetylation of the arylpropanone 10 with the mixed pivalic acetic anhydride ([ 14 C]-11). The resulting pyrylium salt [ 14 C]-12, which is stable and can be stored, is cleaved directly before the feeding experiment to give the diketone [ 14 C]-13 and deprotected to give the free phenolic target molecule [ 14 C]-5. This synthetic route is applicable also to the preparation of 1-(2'-[ 13 C 2 ]acetyl-3'hydroxyphenyl)-2-propanone ([ 13 C 2 ]-5) for biosynthetic experiments with NMR analysis. For the preparation of the oxygen-poorer 13 C-labelled diketone 1-(2'-[methyl- 13 C] acetyl-3'-hydr oxyphenyl)-2-propanone [ 13 C]-8, an 'indanone-route' has been elaborated. (Author)

  16. Genome-wide analysis of cell wall-related genes in Tuber melanosporum.

    Science.gov (United States)

    Balestrini, Raffaella; Sillo, Fabiano; Kohler, Annegret; Schneider, Georg; Faccio, Antonella; Tisserant, Emilie; Martin, Francis; Bonfante, Paola

    2012-06-01

    A genome-wide inventory of proteins involved in cell wall synthesis and remodeling has been obtained by taking advantage of the recently released genome sequence of the ectomycorrhizal Tuber melanosporum black truffle. Genes that encode cell wall biosynthetic enzymes, enzymes involved in cell wall polysaccharide synthesis or modification, GPI-anchored proteins and other cell wall proteins were identified in the black truffle genome. As a second step, array data were validated and the symbiotic stage was chosen as the main focus. Quantitative RT-PCR experiments were performed on 29 selected genes to verify their expression during ectomycorrhizal formation. The results confirmed the array data, and this suggests that cell wall-related genes are required for morphogenetic transition from mycelium growth to the ectomycorrhizal branched hyphae. Labeling experiments were also performed on T. melanosporum mycelium and ectomycorrhizae to localize cell wall components.

  17. Running the Stop Sign: Readthrough of a Premature UAG Termination Signal in the Translation of a Zebrafish (Danio rerio) Taurine Biosynthetic Enzyme.

    Science.gov (United States)

    Larkin, Mary E M; Place, Allen R

    2017-06-03

    The UAG termination codon is generally recognized as the least efficient and least frequently used of the three universal stop codons. This is substantiated by numerous studies in an array of organisms. We present here evidence of a translational readthrough of a mutant nonsense UAG codon in the transcript from the cysteine sulfinic acid decarboxylase ( csad ) gene (ENSDARG00000026348) in zebrafish. The csad gene encodes the terminal enzyme in the taurine biosynthetic pathway. Taurine is a critical amino acid for all animals, playing several essential roles throughout the body, including modulation of the immune system. The sa9430 zebrafish strain (ZDB-ALT-130411-5055) has a point mutation leading to a premature stop codon (UAG) 20 amino acids 5' of the normal stop codon, UGA. Data from immunoblotting, enzyme activity assays, and mass spectrometry provide evidence that the mutant is making a CSAD protein identical to that of the wild-type (XP_009295318.1) in terms of size, activity, and amino acid sequence. UAG readthrough has been described in several species, but this is the first presentation of a case in fish. Also presented are the first data substantiating the ability of a fish CSAD to utilize cysteic acid, an alternative to the standard substrate cysteine sulfinic acid, to produce taurine.

  18. Prequels to Synthetic Biology: From Candidate Gene Identification and Validation to Enzyme Subcellular Localization in Plant and Yeast Cells.

    Science.gov (United States)

    Foureau, E; Carqueijeiro, I; Dugé de Bernonville, T; Melin, C; Lafontaine, F; Besseau, S; Lanoue, A; Papon, N; Oudin, A; Glévarec, G; Clastre, M; St-Pierre, B; Giglioli-Guivarc'h, N; Courdavault, V

    2016-01-01

    Natural compounds extracted from microorganisms or plants constitute an inexhaustible source of valuable molecules whose supply can be potentially challenged by limitations in biological sourcing. The recent progress in synthetic biology combined to the increasing access to extensive transcriptomics and genomics data now provide new alternatives to produce these molecules by transferring their whole biosynthetic pathway in heterologous production platforms such as yeasts or bacteria. While the generation of high titer producing strains remains per se an arduous field of investigation, elucidation of the biosynthetic pathways as well as characterization of their complex subcellular organization are essential prequels to the efficient development of such bioengineering approaches. Using examples from plants and yeasts as a framework, we describe potent methods to rationalize the study of partially characterized pathways, including the basics of computational applications to identify candidate genes in transcriptomics data and the validation of their function by an improved procedure of virus-induced gene silencing mediated by direct DNA transfer to get around possible resistance to Agrobacterium-delivery of viral vectors. To identify potential alterations of biosynthetic fluxes resulting from enzyme mislocalizations in reconstituted pathways, we also detail protocols aiming at characterizing subcellular localizations of protein in plant cells by expression of fluorescent protein fusions through biolistic-mediated transient transformation, and localization of transferred enzymes in yeast using similar fluorescence procedures. Albeit initially developed for the Madagascar periwinkle, these methods may be applied to other plant species or organisms in order to establish synthetic biology platform. © 2016 Elsevier Inc. All rights reserved.

  19. Transcript Quantification by RNA-Seq Reveals Differentially Expressed Genes in the Red and Yellow Fruits of Fragaria vesca.

    Directory of Open Access Journals (Sweden)

    Yuchao Zhang

    Full Text Available Fragaria vesca (2n = 2x = 14, the woodland strawberry, is a perennial herbaceous plant with a small sequenced genome (240 Mb. It is commonly used as a genetic model plant for the Fragaria genus and the Rosaceae family. Fruit skin color is one of the most important traits for both the commercial and esthetic value of strawberry. Anthocyanins are the most prominent pigments in strawberry that bring red, pink, white, and yellow hues to the fruits in which they accumulate. In this study, we conducted a de novo assembly of the fruit transcriptome of woodland strawberry and compared the gene expression profiles with yellow (Yellow Wonder, YW and red (Ruegen, RG fruits. De novo assembly yielded 75,426 unigenes, 21.3% of which were longer than 1,000 bp. Among the high-quality unique sequences, 45,387 (60.2% had at least one significant match to an existing gene model. A total of 595 genes, representing 0.79% of total unigenes, were differentially expressed in YW and RG. Among them, 224 genes were up-regulated and 371 genes were down-regulated in the fruit of YW. Particularly, some flavonoid biosynthetic pathway genes, including C4H, CHS, CHI, F3H, DFR and ANS, as well as some transcription factors (TFs, including MYB (putative MYB86 and MYB39, WDR and MADS, were down-regulated in YW fruit, concurrent with a reduction in anthocyanin accumulation in the yellow pigment phenotype, whereas a putative transcription repressor MYB1R was up-regulated in YW fruit. The altered expression levels of the genes encoding flavonoid biosynthetic enzymes and TFs were confirmed by quantitative RT-PCR. Our study provides important insights into the molecular mechanisms underlying the yellow pigment phenotype in F. vesca.

  20. The immediate nucleotide precursor, guanosine triphosphate, in the riboflavin biosynthetic pathway

    International Nuclear Information System (INIS)

    Mitsuda, Hisateru; Nakajima, Kenji; Nadamoto, Tomonori

    1977-01-01

    In the present paper, the nucleotide precursor of riboflavin was investigated by experiments with labeled purines using non-growing cells of Eremothecium ashbyii. The added purines, at 10 -4 M, were effectively incorporated into riboflavin at an early stage of riboflavin biosynthesis under the experimental conditions. In particular, both labeled xanthine and labeled guanine were specifically transported to guanosine nucleotides, GMP, GDP, GDP-Mannose and GTP, in the course of the riboflavin biosynthesis. A comparison of specific activities of labeled guanosine nucleotides and labeled riboflavin indicated that the nucleotide precursor of riboflavin is guanosine triphosphate. From the results obtained, a biosynthetic pathway of riboflavin is proposed. (auth.)

  1. Synthesis of C-Glucosylated Octaketide Anthraquinones in Nicotiana benthamiana by Using a Multispecies-Based Biosynthetic Pathway.

    Science.gov (United States)

    Andersen-Ranberg, Johan; Kongstad, Kenneth Thermann; Nafisi, Majse; Staerk, Dan; Okkels, Finn Thyge; Mortensen, Uffe Hasbro; Lindberg Møller, Birger; Frandsen, Rasmus John Normand; Kannangara, Rubini

    2017-10-05

    Carminic acid is a C-glucosylated octaketide anthraquinone and the main constituent of the natural dye carmine (E120), possessing unique coloring, stability, and solubility properties. Despite being used since ancient times, longstanding efforts to elucidate its route of biosynthesis have been unsuccessful. Herein, a novel combination of enzymes derived from a plant (Aloe arborescens, Aa), a bacterium (Streptomyces sp. R1128, St), and an insect (Dactylopius coccus, Dc) that allows for the biosynthesis of the C-glucosylated anthraquinone, dcII, a precursor for carminic acid, is reported. The pathway, which consists of AaOKS, StZhuI, StZhuJ, and DcUGT2, presents an alternative biosynthetic approach for the production of polyketides by using a type III polyketide synthase (PKS) and tailoring enzymes originating from a type II PKS system. The current study showcases the power of using transient expression in Nicotiana benthamiana for efficient and rapid identification of functional biosynthetic pathways, including both soluble and membrane-bound enzymes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Altered expression of the caffeine synthase gene in a naturally caffeine-free mutant of Coffea arabica

    Directory of Open Access Journals (Sweden)

    Mirian Perez Maluf

    2009-01-01

    Full Text Available In this work, we studied the biosynthesis of caffeine by examining the expression of genes involved in this biosynthetic pathway in coffee fruits containing normal or low levels of this substance. The amplification of gene-specific transcripts during fruit development revealed that low-caffeine fruits had a lower expression of the theobromine synthase and caffeine synthase genes and also contained an extra transcript of the caffeine synthase gene. This extra transcript contained only part of exon 1 and all of exon 3. The sequence of the mutant caffeine synthase gene revealed the substitution of isoleucine for valine in the enzyme active site that probably interfered with enzymatic activity. These findings indicate that the absence of caffeine in these mutants probably resulted from a combination of transcriptional regulation and the presence of mutations in the caffeine synthase amino acid sequence.

  3. The endogenous transposable element Tgm9 is suitable for functional analyses of soybean genes and generating novel mutants for genetic improvement of soybean

    Science.gov (United States)

    In soybean, variegated flowers can be caused by somatic excision of the CACTA-type transposable element Tgm9 from intron 2 of the DFR2 gene encoding dihydroflavonol-4-reductase in the anthocyanin pigment biosynthetic pathway. DFR2 has been mapped to the W4 locus where the allele containing the elem...

  4. Recent advances in biosynthetic modeling of nitric oxide reductases and insights gained from nuclear resonance vibrational and other spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Saumen; Reed, Julian; Sage, Timothy; Branagan, Nicole C.; Petrik, Igor D.; Miner, Kyle D.; Hu, Michael Y.; Zhao, Jiyong; Alp, E. Ercan; Lu, Yi

    2015-10-05

    This Forum Article focuses on recent advances in structural and spectroscopic studies of biosynthetic models of nitric oxide reductases (NORs). NORs are complex metalloenzymes found in the denitrification pathway of Earth's nitrogen cycle where they catalyze the proton-dependent twoelectron reduction of nitric oxide (NO) to nitrous oxide (N2O). While much progress has been made in biochemical and biophysical studies of native NORs and their variants, a. clear mechanistic understanding of this important metalloenzyme related to its function is still elusive. We report herein UV vis and nuclear resonance vibrational spectroscopy (NRVS) studies of mononitrosylated intermediates of the NOR reaction of a biosynthetic model. The ability to selectively substitute metals at either heme or nonheme metal sites allows the introduction of independent 57Fe probe atoms at either site, as well as allowing the preparation of analogues of stable reaction intermediates by replacing either metal with a redox inactive metal. Together with previous structural and spectroscopic results, we summarize insights gained from studying these biosynthetic models toward understanding structural features responsible for the NOR activity and its mechanism. As a result, the outlook on NOR modeling is also discussed, with an emphasis on the design of models capable of catalytic turnovers designed based on close mimics of the secondary coordination sphere of native NORs.

  5. An efficient approach to finding Siraitia grosvenorii triterpene biosynthetic genes by RNA-seq and digital gene expression analysis

    Directory of Open Access Journals (Sweden)

    Song Cai

    2011-07-01

    Full Text Available Abstract Background Siraitia grosvenorii (Luohanguo is an herbaceous perennial plant native to southern China and most prevalent in Guilin city. Its fruit contains a sweet, fleshy, edible pulp that is widely used in traditional Chinese medicine. The major bioactive constituents in the fruit extract are the cucurbitane-type triterpene saponins known as mogrosides. Among them, mogroside V is nearly 300 times sweeter than sucrose. However, little is known about mogrosides biosynthesis in S. grosvenorii, especially the late steps of the pathway. Results In this study, a cDNA library generated from of equal amount of RNA taken from S. grosvenorii fruit at 50 days after flowering (DAF and 70 DAF were sequenced using Illumina/Solexa platform. More than 48,755,516 high-quality reads from a cDNA library were generated that was assembled into 43,891 unigenes. De novo assembly and gap-filling generated 43,891 unigenes with an average sequence length of 668 base pairs. A total of 26,308 (59.9% unique sequences were annotated and 11,476 of the unique sequences were assigned to specific metabolic pathways by the Kyoto Encyclopedia of Genes and Genomes. cDNA sequences for all of the known enzymes involved in mogrosides backbone synthesis were identified from our library. Additionally, a total of eighty-five cytochrome P450 (CYP450 and ninety UDP-glucosyltransferase (UDPG unigenes were identified, some of which appear to encode enzymes responsible for the conversion of the mogroside backbone into the various mogrosides. Digital gene expression profile (DGE analysis using Solexa sequencing was performed on three important stages of fruit development, and based on their expression pattern, seven CYP450s and five UDPGs were selected as the candidates most likely to be involved in mogrosides biosynthesis. Conclusion A combination of RNA-seq and DGE analysis based on the next generation sequencing technology was shown to be a powerful method for identifying

  6. Identification and sequence analysis of Sulfolobus solfataricus purE and purK genes

    DEFF Research Database (Denmark)

    Sørensen, Iben Schildt; Dandanell, Gert

    1997-01-01

    From a genomic library of Sulfolobus solfataricus DSM1617 we have isolated and identified the purEK locus. Two open reading frames are identified as homologs of the purE and purK purine biosynthetic genes in Escherichia coli. The C-terminus of purE overlaps with the N-terminus of purK. When either...... of the genes is expressed from an E. coli promoter they can complement the corresponding purE and purK mutations in E. coli. PurE seems to be more closely related to eubacteria than to other archaea and to eukaryotes. Also the purK gene, which has not yet been found in other archaea, is more closely related...

  7. Integrating toxin gene expression, growth and fumonisin B1 and B2 production by a strain of Fusarium verticillioides under different environmental factors

    Science.gov (United States)

    Medina, Angel; Schmidt-Heydt, Markus; Cárdenas-Chávez, Diana L.; Parra, Roberto; Geisen, Rolf; Magan, Naresh

    2013-01-01

    The objective of this study was to integrate data on the effect of water activity (aw; 0.995–0.93) and temperature (20–35°C) on activation of the biosynthetic FUM genes, growth and the mycotoxins fumonisin (FB1, FB2) by Fusarium verticillioides in vitro. The relative expression of nine biosynthetic cluster genes (FUM1, FUM7, FUM10, FUM11, FUM12, FUM13, FUM14, FUM16 and FUM19) in relation to the environmental factors was determined using a microarray analysis. The expression was related to growth and phenotypic FB1 and FB2 production. These data were used to develop a mixed-growth-associated product formation model and link this to a linear combination of the expression data for the nine genes. The model was then validated by examining datasets outside the model fitting conditions used (35°C). The relationship between the key gene (FUM1) and other genes in the cluster (FUM11, FUM13, FUM9, FUM14) were examined in relation to aw, temperature, FB1 and FB2 production by developing ternary diagrams of relative expression. This model is important in developing an integrated systems approach to develop prevention strategies to control fumonisin biosynthesis in staple food commodities and could also be used to predict the potential impact that climate change factors may have on toxin production. PMID:23697716

  8. Overexpression of erg1 gene in Trichoderma harzianum CECT 2413: effect on the induction of tomato defence-related genes.

    Science.gov (United States)

    Cardoza, R E; Malmierca, M G; Gutiérrez, S

    2014-09-01

    To investigate the effect of the overexpression of erg1 gene of Trichoderma harzianum CECT 2413 (T34) on the Trichoderma-plant interactions and in the biocontrol ability of this fungus. Transformants of T34 strain overexpressing erg1 gene did not show effect on the ergosterol level, although a drastic decrease in the squalene level was observed in the transformants at 96 h of growth. During interaction with plants, the erg1 overexpression resulted in a reduction of the priming ability of several tomato defence-related genes belonging to the salicylate pathway, and also of the TomLoxA gene, which is related to the jasmonate pathway. Interestingly, other jasmonate-related genes, such as PINI and PINII, were slightly induced. The erg1 overexpressed transformants also showed a reduced ability to colonize tomato roots. The ergosterol biosynthetic pathway might play an important role in regulating Trichoderma-plant interactions, although this role does not seem to be restricted to the final product; instead, other intermediates such as squalene, whose role in the Trichoderma-plant interaction has not been characterized, would also play an important role. The functional analysis of genes involved in the synthesis of ergosterol could provide additional strategies to improve the ability of biocontrol of the Trichoderma strains and their interaction with plants. © 2014 The Society for Applied Microbiology.

  9. Flowery odor formation revealed by differential expression of monoterpene biosynthetic genes and monoterpene accumulation in rose (Rosa rugosa Thunb.).

    Science.gov (United States)

    Feng, Liguo; Chen, Chen; Li, Tinglin; Wang, Meng; Tao, Jun; Zhao, Daqiu; Sheng, Lixia

    2014-02-01

    Rosa rugosa is an important ornamental and economical plant. In this paper, four genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (DXS), 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), alcohol acyltransferase (AAT) and linalool synthase (LIS) involved in the monoterpene biosynthesis pathways were isolated from R. rugosa 'Tangzi', and the expression patterns of these genes in different flower development stages and different parts of floral organs were determined by real-time quantitative fluorescence PCR. Furthermore, a comprehensive analysis was carried out into the relationship between expression of four monoterpene synthesis genes and accumulation of main volatile monoterpenes and their acetic acid ester derivatives. The results showed that the genes RrDXS, RrDXR and RrLIS showed consistent expressions during the development process for R. rugosa flower from budding to withering stage, the overall expression levels of gene RrDXS and RrLIS were obviously lower as compared with those of gene RrDXR and RrAAT. Although the gene RrDXS, RrDXR, RrAAT and RrLIS were expressed in all parts of R. rugosa floral organs, the expression levels varied significantly. The variations in the constituent and content of volatile monoterpenes including citronellol, geraniol, nerol, linalool, citronellyl acetate, geranyl acetate and neryl acetate at different development stages and parts of floral organs were significantly different. On this basis, we concluded that the gene RrDXR and RrAAT might play a key role in the biosynthesis of volatile monoterpenes in R. rugosa flowers, and the two genes are important candidate genes for the regulation of secondary metabolism for rose aromatic components. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  10. Biosynthetic routes of hydroxylated carotenoids (xanthophylls) in Marchantia polymorpha, and production of novel and rare xanthophylls through pathway engineering in Escherichia coli.

    Science.gov (United States)

    Takemura, Miho; Maoka, Takashi; Misawa, Norihiko

    2015-03-01

    MpBHY codes for a carotene β-ring 3(,3')-hydroxylase responsible for both zeaxanthin and lutein biosynthesis in liverwort. MpCYP97C functions as an ε-ring hydroxylase (zeinoxanthin 3'-hydroxylase) to produce lutein in liverwort. Xanthophylls are oxygenated or hydroxylated carotenes that are most abundant in the light-harvesting complexes of plants. The plant-type xanthophylls consist of α-xanthophyll (lutein) and β-xanthophylls (zeaxanthin, antheraxanthin, violaxanthin and neoxanthin). The α-xanthophyll and β-xanthophylls are derived from α-carotene and β-carotene by carotene hydroxylase activities, respectively. β-Ring 3,3'-hydroxylase that mediates the route of zeaxanthin from β-carotene via β-cryptoxanthin is present in higher plants and is encoded by the BHY (BCH) gene. On the other hand, CYP97A (or BHY) and CYP97C genes are responsible for β-ring 3-hydroxylation and ε-ring 3'-hydroxylation, respectively, in routes from α-carotene to lutein. To elucidate the evolution of the biosynthetic routes of such hydroxylated carotenoids from carotenes in land plants, we identified and functionally analyzed carotenoid hydroxylase genes of liverwort Marchantia polymorpha L. Three genes homologous to higher plants, BHY, CYP97A, and CYP97C, were isolated and named MpBHY, MpCYP97A, and MpCYP97C, respectively. MpBHY was found to code for β-ring hydroxylase, which is responsible for both routes starting from β-carotene and α-carotene. MpCYP97C functioned as an ε-ring hydroxylase not for α-carotene but for zeinoxanthin, while MpCYP97A showed no hydroxylation activity for β-carotene or α-carotene. These findings suggest the original functions of the hydroxylation enzymes of carotenes in land plants, which are thought to diversify in higher plants. In addition, we generated recombinant Escherichia coli cells, which produced rare and novel carotenoids such as α-echinenone and 4-ketozeinoxanthin, through pathway engineering using bacterial carotenogenic genes

  11. Signal Transduction Pathways that Regulate CAB Gene Expression

    Energy Technology Data Exchange (ETDEWEB)

    Chory, Joanne

    2004-12-31

    The process of chloroplast differentiation, involves the coordinate regulation of many nuclear and chloroplast genes. The cues for the initiation of this developmental program are both extrinsic (e.g., light) and intrinsic (cell-type and plastid signals). During this project period, we utilized a molecular genetic approach to select for Arabidopsis mutants that did not respond properly to environmental light conditions, as well as mutants that were unable to perceive plastid damage. These latter mutants, called gun mutants, define two retrograde signaling pathways that regulate nuclear gene expression in response to chloroplasts. A major finding was to identify a signal from chloroplasts that regulates nuclear gene transcription. This signal is the build-up of Mg-Protoporphyrin IX, a key intermediate of the chlorophyll biosynthetic pathway. The signaling pathways downstream of this signal are currently being studied. Completion of this project has provided an increased understanding of the input signals and retrograde signaling pathways that control nuclear gene expression in response to the functional state of chloroplasts. These studies should ultimately influence our abilities to manipulate plant growth and development, and will aid in the understanding of the developmental control of photosynthesis.

  12. Signal Transduction Pathways that Regulate CAB Gene Expression

    Energy Technology Data Exchange (ETDEWEB)

    Chory, Joanne

    2006-01-16

    The process of chloroplast differentiation, involves the coordinate regulation of many nuclear and chloroplast genes. The cues for the initiation of this developmental program are both extrinsic (e.g., light) and intrinsic (cell-type and plastid signals). During this project period, we utilized a molecular genetic approach to select for Arabidopsis mutants that did not respond properly to environmental light conditions, as well as mutants that were unable to perceive plastid damage. These latter mutants, called gun mutants, define two retrograde signaling pathways that regulate nuclear gene expression in response to chloroplasts. A major finding was to identify a signal from chloroplasts that regulates nuclear gene transcription. This signal is the build-up of Mg-Protoporphyrin IX, a key intermediate of the chlorophyll biosynthetic pathway. The signaling pathways downstream of this signal are currently being studied. Completion of this project has provided an increased understanding of the input signals and retrograde signaling pathways that control nuclear gene expression in response to the functional state of chloroplasts. These studies should ultimately influence our abilities to manipulate plant growth and development, and will aid in the understanding of the developmental control of photosynthesis.

  13. Biosynthetic origin of acetic acid using SNIF-NMR; Determinacao da origem biossintetica de acido acetico atraves da tecnica 'Site Specific Natural Isotopic Fractionation Studied by Nuclear Magnetic Resonance (SNIF-NMR)'

    Energy Technology Data Exchange (ETDEWEB)

    Boffo, Elisangela Fabiana; Ferreira, Antonio Gilberto [Sao Carlos Univ., SP (Brazil). Dept. de Quimica

    2006-05-15

    The main purpose of this work is to describe the use of the technique Site-Specific Natural Isotopic Fractionation of hydrogen (SNIF-NMR), using {sup 2}H and {sup 1}H NMR spectroscopy, to investigate the biosynthetic origin of acetic acid in commercial samples of Brazilian vinegar. This method is based on the deuterium to hydrogen ratio at a specific position (methyl group) of acetic acitained by fermentation, through different biosynthetic mechanisms, which result in different isotopic ratios. We measured the isotopic ratio of vinegars obtained through C{sub 3}, C{sub 4}, and CAM biosynthetic mechanisms, blends of C{sub 3} and C{sub 4} (agrins) and synthetic acetic acid. (author)

  14. Fruit specific variability in capsaicinoid accumulation and transcription of structural and regulatory genes in Capsicum fruit.

    Science.gov (United States)

    Keyhaninejad, Neda; Curry, Jeanne; Romero, Joslynn; O'Connell, Mary A

    2014-02-01

    Accumulation of capsaicinoids in the placental tissue of ripening chile (Capsicum spp.) fruit follows the coordinated expression of multiple biosynthetic enzymes producing the substrates for capsaicin synthase. Transcription factors are likely agents to regulate expression of these biosynthetic genes. Placental RNAs from habanero fruit (Capsicum chinense) were screened for expression of candidate transcription factors; with two candidate genes identified, both in the ERF family of transcription factors. Characterization of these transcription factors, Erf and Jerf, in nine chile cultivars with distinct capsaicinoid contents demonstrated a correlation of expression with pungency. Amino acid variants were observed in both ERF and JERF from different chile cultivars; none of these changes involved the DNA binding domains. Little to no transcription of Erf was detected in non-pungent Capsium annuum or C. chinense mutants. This correlation was characterized at an individual fruit level in a set of jalapeño (C. annuum) lines again with distinct and variable capsaicinoid contents. Both Erf and Jerf are expressed early in fruit development, 16-20 days post-anthesis, at times prior to the accumulation of capsaicinoids in the placental tissues. These data support the hypothesis that these two members of the complex ERF family participate in regulation of the pungency phenotype in chile. Copyright © 2013. Published by Elsevier Ireland Ltd.

  15. Metabolic engineering of biosynthetic pathway for production of renewable biofuels.

    Science.gov (United States)

    Singh, Vijai; Mani, Indra; Chaudhary, Dharmendra Kumar; Dhar, Pawan Kumar

    2014-02-01

    Metabolic engineering is an important area of research that involves editing genetic networks to overproduce a certain substance by the cells. Using a combination of genetic, metabolic, and modeling methods, useful substances have been synthesized in the past at industrial scale and in a cost-effective manner. Currently, metabolic engineering is being used to produce sufficient, economical, and eco-friendly biofuels. In the recent past, a number of efforts have been made towards engineering biosynthetic pathways for large scale and efficient production of biofuels from biomass. Given the adoption of metabolic engineering approaches by the biofuel industry, this paper reviews various approaches towards the production and enhancement of renewable biofuels such as ethanol, butanol, isopropanol, hydrogen, and biodiesel. We have also identified specific areas where more work needs to be done in the future.

  16. Methylation effect on chalcone synthase gene expression determines anthocyanin pigmentation in floral tissues of two Oncidium orchid cultivars.

    Science.gov (United States)

    Liu, Xiao-Jing; Chuang, Yao-Nung; Chiou, Chung-Yi; Chin, Dan-Chu; Shen, Fu-Quan; Yeh, Kai-Wun

    2012-08-01

    The anthocyanin-biosynthetic pathway was studied in flowers of Oncidium Gower Ramsey with yellow floral color and mosaic red anthocyanin in lip crests, sepals and petals, and compared with the anthocyanin biosynthesis in flowers of Oncidium Honey Dollp, a natural somatoclone derived from tissue culture of Gower Ramsey, with a yellow perianth without red anthocyanins in floral tissues. HPLC analysis revealed that the red anthocyanin in lip crests of the Gower Ramsey cultivar comprised peonidin-3-O-glucoside, delphinidin-3-O-glucoside and cyanidin-3-O-glucoside, whereas Honey Dollp was devoid of anthocyanin compounds. Among the five anthocyanin-biosynthetic genes, OgCHS was actively expressed in lip crests of Gower Ramsey flowers, but no transcripts of OgCHS were detected in Honey Dollp floral tissues. Transient expression of OgCHS by bombardment confirmed that recovery of the OgCHS gene expression completed the anthocyanin pathway and produced anthocyanin compounds in lip crests of Honey Dollp flowers. Transcription factor genes regulating anthocyanin biosynthesis showed no distinctive differences in the expression level of OgMYB1, OgbHLH and OgWD40 between the two cultivars. A methylation assay revealed that the promoter of OgCHS was not methylated in Gower Ramsey, while a positive methylation effect was present in the upstream promoter region of OgCHS in Honey Dollp. Overall, our results suggest that the failure of anthocyanin accumulation in Honey Dollp floral tissues may be attributed to inactivation of the OgCHS gene resulting from the epigenetic methylation of 5'-upstream promoter region.

  17. Cloning and characterization of genes involved in nostoxanthin biosynthesis of Sphingomonas elodea ATCC 31461.

    Directory of Open Access Journals (Sweden)

    Liang Zhu

    Full Text Available Most Sphingomonas species synthesize the yellow carotenoid nostoxanthin. However, the carotenoid biosynthetic pathway of these species remains unclear. In this study, we cloned and characterized a carotenoid biosynthesis gene cluster containing four carotenogenic genes (crtG, crtY, crtI and crtB and a β-carotene hydroxylase gene (crtZ located outside the cluster, from the gellan-gum producing bacterium Sphingomonas elodea ATCC 31461. Each of these genes was inactivated, and the biochemical function of each gene was confirmed based on chromatographic and spectroscopic analysis of the intermediates accumulated in the knockout mutants. Moreover, the crtG gene encoding the 2,2'-β-hydroxylase and the crtZ gene encoding the β-carotene hydroxylase, both responsible for hydroxylation of β-carotene, were confirmed by complementation studies using Escherichia coli producing different carotenoids. Expression of crtG in zeaxanthin and β-carotene accumulating E. coli cells resulted in the formation of nostoxanthin and 2,2'-dihydroxy-β-carotene, respectively. Based on these results, a biochemical pathway for synthesis of nostoxanthin in S. elodea ATCC 31461 is proposed.

  18. Cloning and characterization of genes involved in nostoxanthin biosynthesis of Sphingomonas elodea ATCC 31461.

    Science.gov (United States)

    Zhu, Liang; Wu, Xuechang; Li, Ou; Qian, Chaodong; Gao, Haichun

    2012-01-01

    Most Sphingomonas species synthesize the yellow carotenoid nostoxanthin. However, the carotenoid biosynthetic pathway of these species remains unclear. In this study, we cloned and characterized a carotenoid biosynthesis gene cluster containing four carotenogenic genes (crtG, crtY, crtI and crtB) and a β-carotene hydroxylase gene (crtZ) located outside the cluster, from the gellan-gum producing bacterium Sphingomonas elodea ATCC 31461. Each of these genes was inactivated, and the biochemical function of each gene was confirmed based on chromatographic and spectroscopic analysis of the intermediates accumulated in the knockout mutants. Moreover, the crtG gene encoding the 2,2'-β-hydroxylase and the crtZ gene encoding the β-carotene hydroxylase, both responsible for hydroxylation of β-carotene, were confirmed by complementation studies using Escherichia coli producing different carotenoids. Expression of crtG in zeaxanthin and β-carotene accumulating E. coli cells resulted in the formation of nostoxanthin and 2,2'-dihydroxy-β-carotene, respectively. Based on these results, a biochemical pathway for synthesis of nostoxanthin in S. elodea ATCC 31461 is proposed.

  19. ColoLipidGene: signature of lipid metabolism-related genes to predict prognosis in stage-II colon cancer patients

    Science.gov (United States)

    Vargas, Teodoro; Moreno-Rubio, Juan; Herranz, Jesús; Cejas, Paloma; Molina, Susana; González-Vallinas, Margarita; Mendiola, Marta; Burgos, Emilio; Aguayo, Cristina; Custodio, Ana B.; Machado, Isidro; Ramos, David; Gironella, Meritxell; Espinosa-Salinas, Isabel; Ramos, Ricardo; Martín-Hernández, Roberto; Risueño, Alberto; De Las Rivas, Javier; Reglero, Guillermo; Yaya, Ricardo; Fernández-Martos, Carlos; Aparicio, Jorge; Maurel, Joan; Feliu, Jaime; de Molina, Ana Ramírez

    2015-01-01

    Lipid metabolism plays an essential role in carcinogenesis due to the requirements of tumoral cells to sustain increased structural, energetic and biosynthetic precursor demands for cell proliferation. We investigated the association between expression of lipid metabolism-related genes and clinical outcome in intermediate-stage colon cancer patients with the aim of identifying a metabolic profile associated with greater malignancy and increased risk of relapse. Expression profile of 70 lipid metabolism-related genes was determined in 77 patients with stage II colon cancer. Cox regression analyses using c-index methodology was applied to identify a metabolic-related signature associated to prognosis. The metabolic signature was further confirmed in two independent validation sets of 120 patients and additionally, in a group of 264 patients from a public database. The combined analysis of these 4 genes, ABCA1, ACSL1, AGPAT1 and SCD, constitutes a metabolic-signature (ColoLipidGene) able to accurately stratify stage II colon cancer patients with 5-fold higher risk of relapse with strong statistical power in the four independent groups of patients. The identification of a group of 4 genes that predict survival in intermediate-stage colon cancer patients allows delineation of a high-risk group that may benefit from adjuvant therapy, and avoids the toxic and unnecessary chemotherapy in patients classified as low-risk group. PMID:25749516

  20. Molecular cloning of a novel bioH gene from an environmental metagenome encoding a carboxylesterase with exceptional tolerance to organic solvents

    DEFF Research Database (Denmark)

    Shi, Yuping; Pan, Yingjie; Li, Bailin

    2013-01-01

    with a strong potential in industrial applications. CONCLUSIONS: This study constituted the first investigation of a novel bioHx gene in a biotin biosynthetic gene cluster cloned from an environmental metagenome. The bioHx gene was successfully cloned, expressed and characterized. The results demonstrated...... that BioHx is a novel carboxylesterase, displaying distinct biochemical properties with strong application potential in industry. Our results also provided the evidence for the effectiveness of functional metagenomic approach for identifying novel bioH genes from complex ecosystem.......ABSTRACT: BACKGROUND: BioH is one of the key enzymes to produce the precursor pimeloyl-ACP to initiate biotin biosynthesis de novo in bacteria. To date, very few bioH genes have been characterized. In this study, we cloned and identified a novel bioH gene, bioHx, from an environmental metagenome...

  1. Transcriptome and metabolome analysis of Ferula gummosa Boiss. to reveal major biosynthetic pathways of galbanum compounds.

    Science.gov (United States)

    Sobhani Najafabadi, Ahmad; Naghavi, Mohammad Reza; Farahmand, Hamid; Abbasi, Alireza

    2017-11-01

    Ferula gummosa Boiss. is an industrial and pharmaceutical plant that has been highly recognized for its valuable oleo-gum-resin, namely galbanum. Despite the fabulous value of galbanum, very little information on the genetic and biochemical mechanisms of its production existed. In the present study, the oleo-gum-resin and four organs (root, flower, stem, and leaf) of F. gummosa were assessed in terms of metabolic compositions and the expression of genes involved in their biosynthetic pathways. Results showed that the most accumulation of resin and essential oils were occurred in the roots (13.99 mg/g) and flowers (6.01 mg/g), respectively. While the most dominant compound of the resin was β-amyrin from triterpenes, the most abundant compounds of the essential oils were α-pinene and β-pinene from monoterpenes and α-eudesmol and germacrene-D from sesquiterpenes. Transcriptome analysis was performed by RNA sequencing (RNA-seq) for the plant roots and flowers. Differential gene expression analysis showed that 1172 unigenes were differential between two organs that 934 (79.6%) of them were up-regulated in the flowers and 238 (20.4%) unigenes were up-regulated in the roots (FDR ≤0.001). The most important up-regulated unigenes in the roots were involved in the biosynthesis of the major components of galbanum, including myrcene, germacrene-D, α-terpineol, and β-amyrin. The results obtained by RNA-Seq were confirmed by qPCR. These analyses showed that different organs of F. gummosa are involved in the production of oleo-gum-resin, but the roots are more active than other organs in terms of the biosynthesis of triterpenes and some mono- and sesquiterpenes. This study provides rich molecular and biochemical resources for further studies on molecular genetics and functional genomics of oleo-gum-resin production in F. gummosa.

  2. Self-excising Cre/mutant lox marker recycling system for multiple gene integrations and consecutive gene deletions in Aspergillus oryzae.

    Science.gov (United States)

    Zhang, Silai; Ban, Akihiko; Ebara, Naoki; Mizutani, Osamu; Tanaka, Mizuki; Shintani, Takahiro; Gomi, Katsuya

    2017-04-01

    In this study, we developed a self-excising Cre/loxP-mediated marker recycling system with mutated lox sequences to introduce a number of biosynthetic genes into Aspergillus oryzae. To construct the self-excising marker cassette, both the selectable marker, the Aspergillus nidulans adeA gene, and the Cre recombinase gene (cre), conditionally expressed by the xylanase-encoding gene promoter, were designed to be located between the mutant lox sequences, lox66 and lox71. However, construction of the plasmid failed, possibly owing to a slight expression of cre downstream of the fungal gene promoter in Escherichia coli. Hence, to avoid the excision of the cassette in E. coli, a 71-bp intron of the A. oryzae xynG2 gene was inserted into the cre gene. The A. oryzae adeA deletion mutant was transformed with the resulting plasmid in the presence of glucose, and the transformants were cultured in medium containing xylose as the sole carbon source. PCR analysis of genomic DNA from resultant colonies revealed the excision of both the marker and Cre expression construct, indicating that the self-excising marker cassette was efficient at removing the selectable marker. Using the marker recycling system, hyperproduction of kojic acid could be achieved in A. oryzae by the introduction of two genes that encode oxidoreductase and transporter. Furthermore, we also constructed an alternative marker recycling cassette bearing the A. nidulans pyrithiamine resistant gene (ptrA) as a dominant selectable marker. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Differential Lipid Composition and Gene Expression in the Semi-Russeted “Cox Orange Pippin” Apple Variety

    OpenAIRE

    Legay, Sylvain; Cocco, Emmanuelle; André, Christelle M.; Guignard, Cédric; Hausman, Jean-Francois; Guerriero, Gea

    2017-01-01

    Russeting is characterized by a particular rough and brown phenotype, which is mainly due to the accumulation of suberin in the inner part of the epidermal cell walls. In our previous bulk transcriptomic analysis, comparing fully russeted, and waxy apple varieties, showed, in apple fruit skin, a massive decreased expression of cutin, wax and some pentacyclic triterpene biosynthesis genes in the russeted varieties, with an expected concomitant enhanced expression of the suberin biosynthetic ge...

  4. A roadmap for natural product discovery based on large-scale genomics and metabolomics

    Science.gov (United States)

    Actinobacteria encode a wealth of natural product biosynthetic gene clusters, whose systematic study is complicated by numerous repetitive motifs. By combining several metrics we developed a method for global classification of these gene clusters into families (GCFs) and analyzed the biosynthetic ca...

  5. Targeting the GPI biosynthetic pathway.

    Science.gov (United States)

    Yadav, Usha; Khan, Mohd Ashraf

    2018-02-27

    The GPI (Glycosylphosphatidylinositol) biosynthetic pathway is a multistep conserved pathway in eukaryotes that culminates in the generation of GPI glycolipid which in turn anchors many proteins (GPI-APs) to the cell surface. In spite of the overall conservation of the pathway, there still exist subtle differences in the GPI pathway of mammals and other eukaryotes which holds a great promise so far as the development of drugs/inhibitors against specific targets in the GPI pathway of pathogens is concerned. Many of the GPI structures and their anchored proteins in pathogenic protozoans and fungi act as pathogenicity factors. Notable examples include GPI-anchored variant surface glycoprotein (VSG) in Trypanosoma brucei, GPI-anchored merozoite surface protein 1 (MSP1) and MSP2 in Plasmodium falciparum, protein-free GPI related molecules like lipophosphoglycans (LPGs) and glycoinositolphospholipids (GIPLs) in Leishmania spp., GPI-anchored Gal/GalNAc lectin and proteophosphoglycans in Entamoeba histolytica or the GPI-anchored mannoproteins in pathogenic fungi like Candida albicans. Research in this active area has already yielded encouraging results in Trypanosoma brucei by the development of parasite-specific inhibitors of GlcNCONH 2 -β-PI, GlcNCONH 2 -(2-O-octyl)-PI and salicylic hydroxamic acid (SHAM) targeting trypanosomal GlcNAc-PI de-N-acetylase as well as the development of antifungal inhibitors like BIQ/E1210/gepinacin/G365/G884 and YW3548/M743/M720 targeting the GPI specific fungal inositol acyltransferase (Gwt1) and the phosphoethanolamine transferase-I (Mcd4), respectively. These confirm the fact that the GPI pathway continues to be the focus of researchers, given its implications for the betterment of human life.

  6. A fast and simple GC MS method for lignan profiling in Anthriscus sylvestris and biosynthetically related plant species

    NARCIS (Netherlands)

    Koulman, A; Bos, R; Medarde, M; Pras, N; Quax, WJ

    2001-01-01

    A new GC-MS method for monitoring lignans was developed to study the variation in plants and elucidate the biosynthetic steps. A simple and fast extraction procedure for lyophilised plant material was developed, giving a lignan-rich extract. A GC-MS method was set up using an apolar WCOT fused

  7. antiSMASH 4.0-improvements in chemistry prediction and gene cluster boundary identification

    DEFF Research Database (Denmark)

    Blin, Kai; Wolf, Thomas; Chevrette, Marc G.

    2017-01-01

    Many antibiotics, chemotherapeutics, crop protection agents and food preservatives originate from molecules produced by bacteria, fungi or plants. In recent years, genome mining methodologies have been widely adopted to identify and characterize the biosynthetic gene clusters encoding...... the production of such compounds. Since 2011, the 'antibiotics and secondary metabolite analysis shell-antiSMASH' has assisted researchers in efficiently performing this, both as a web server and a standalone tool. Here, we present the thoroughly updated antiSMASH version 4, which adds several novel features...

  8. Analysis of occludin trafficking, demonstrating continuous endocytosis, degradation, recycling and biosynthetic secretory trafficking.

    Directory of Open Access Journals (Sweden)

    Sarah J Fletcher

    Full Text Available Tight junctions (TJs link adjacent cells and are critical for maintenance of apical-basolateral polarity in epithelial monolayers. The TJ protein occludin functions in disparate processes, including wound healing and Hepatitis C Virus infection. Little is known about steady-state occludin trafficking into and out of the plasma membrane. Therefore, we determined the mechanisms responsible for occludin turnover in confluent Madin-Darby canine kidney (MDCK epithelial monolayers. Using various biotin-based trafficking assays we observed continuous and rapid endocytosis of plasma membrane localised occludin (the majority internalised within 30 minutes. By 120 minutes a significant reduction in internalised occludin was observed. Inhibition of lysosomal function attenuated the reduction in occludin signal post-endocytosis and promoted co-localisation with the late endocytic system. Using a similar method we demonstrated that ∼20% of internalised occludin was transported back to the cell surface. Consistent with these findings, significant co-localisation between internalised occludin and recycling endosomal compartments was observed. We then quantified the extent to which occludin synthesis and transport to the plasma membrane contributes to plasma membrane occludin homeostasis, identifying inhibition of protein synthesis led to decreased plasma membrane localised occludin. Significant co-localisation between occludin and the biosynthetic secretory pathway was demonstrated. Thus, under steady-state conditions occludin undergoes turnover via a continuous cycle of endocytosis, recycling and degradation, with degradation compensated for by biosynthetic exocytic trafficking. We developed a mathematical model to describe the endocytosis, recycling and degradation of occludin, utilising experimental data to provide quantitative estimates for the rates of these processes.

  9. Toxicity of a furanocoumarin to armyworms: a case of biosynthetic escape from insect herbivores.

    Science.gov (United States)

    Berenbaum, M

    1978-08-11

    When the linear furanocoumarin xanthotoxin, found in many plants of the families Rutaceae and Umbelliferae, was administered to larvae of Spodoptera eridania, a generalist insect herbivore, it displayed toxic properties lacking in its biosynthetic precursor umbelliferone. Reduced toxicity observed in the absence of ultraviolet light is consistent with the known mechanism of photoinactivation of DNA by furanocoumarins through ultraviolet-catalyzed cross-linkage of strands. Thus, the ability of a plant to convert umbelliferone to linear furanocoumarins appears to confer broader protection against insect herbivores.

  10. ASKA STOL research aircraft flight tests and evaluation. STOL jikkenki Asuka'' no hiko shiken kekka

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, M; Inoue, T; Tobinaga, Y; Tsuji, H [Kawasaki Heavy Industries, Ltd., Tokyo (Japan)

    1991-07-20

    The present report evaluated the powered high-lift device (PHLD) distance of upper surface blowing (USB) system, basing the materialization of short distance take-off and landing (STOL) performance, one of the main flight test purposes by the Aska'', quiet STOL research aircraft, which evaluation was then added with reporting its flight test result to cover several topics. As prototypical, a C-1 tactical transport aircraft produced by Kawasaki Heavy Industries was modified to the aska'' together with the following change in design for the STOL flight test: Adoption was made of a PHLD of USB system where the wing surface was mounted with four turbofan jet engines thereon. Application was made of a boundary layer control (BLC) to the main wing leading edge and aileron. Mounting was made of a stability and control augmentation system (SCAS) using a triple system digital computer. Fitting was made of a vortex generator for the prevention from peeling by jet exhaust. As a result of flight test, the recorded distance was confirmed to be 1580ft in landing and 1670ft in take-off. 5 refs., 15 figs., 2 tabs.

  11. Point mutations in a nucleoside transporter gene from Leishmania donovani confer drug resistance and alter substrate selectivity

    OpenAIRE

    Vasudevan, Gayatri; Ullman, Buddy; Landfear, Scott M.

    2001-01-01

    Leishmania parasites lack a purine biosynthetic pathway and depend on surface nucleoside and nucleobase transporters to provide them with host purines. Leishmania donovani possess two closely related genes that encode high affinity adenosine-pyrimidine nucleoside transporters LdNT1.1 and LdNT1.2 and that transport the toxic adenosine analog tubercidin in addition to the natural substrates. In this study, we have characterized a drug-resistant clonal mutant of L. do...

  12. Action of multiple intra-QTL genes concerted around a co-localized transcription factor underpins a large effect QTL

    Science.gov (United States)

    Dixit, Shalabh; Kumar Biswal, Akshaya; Min, Aye; Henry, Amelia; Oane, Rowena H.; Raorane, Manish L.; Longkumer, Toshisangba; Pabuayon, Isaiah M.; Mutte, Sumanth K.; Vardarajan, Adithi R.; Miro, Berta; Govindan, Ganesan; Albano-Enriquez, Blesilda; Pueffeld, Mandy; Sreenivasulu, Nese; Slamet-Loedin, Inez; Sundarvelpandian, Kalaipandian; Tsai, Yuan-Ching; Raghuvanshi, Saurabh; Hsing, Yue-Ie C.; Kumar, Arvind; Kohli, Ajay

    2015-01-01

    Sub-QTLs and multiple intra-QTL genes are hypothesized to underpin large-effect QTLs. Known QTLs over gene families, biosynthetic pathways or certain traits represent functional gene-clusters of genes of the same gene ontology (GO). Gene-clusters containing genes of different GO have not been elaborated, except in silico as coexpressed genes within QTLs. Here we demonstrate the requirement of multiple intra-QTL genes for the full impact of QTL qDTY12.1 on rice yield under drought. Multiple evidences are presented for the need of the transcription factor ‘no apical meristem’ (OsNAM12.1) and its co-localized target genes of separate GO categories for qDTY12.1 function, raising a regulon-like model of genetic architecture. The molecular underpinnings of qDTY12.1 support its effectiveness in further improving a drought tolerant genotype and for its validity in multiple genotypes/ecosystems/environments. Resolving the combinatorial value of OsNAM12.1 with individual intra-QTL genes notwithstanding, identification and analyses of qDTY12.1has fast-tracked rice improvement towards food security. PMID:26507552

  13. Tissue- Specific Expression Analysis of Anthocyanin Biosynthetic Genes in White- and Red-Fleshed Grape Cultivars

    Directory of Open Access Journals (Sweden)

    Sha Xie

    2015-12-01

    Full Text Available Yan73, a teinturier (dyer grape variety in China, is one of the few Vitis vinifera cultivars with red-coloured berry flesh. To examine the tissue-specific expression of genes associated with berry colour in Yan73, we analysed the differential accumulation of anthocyanins in the skin and flesh tissues of two red-skinned grape varieties with either red (Yan73 or white flesh (Muscat Hamburg based on HPLC-MS analysis, as well as the differential expression of 18 anthocyanin biosynthesis genes in both varieties by quantitative RT-PCR. The results revealed that the transcripts of GST, OMT, AM3, CHS3, UFGT, MYBA1, F3′5′H, F3H1 and LDOX were barely detectable in the white flesh of Muscat Hamburg. In particular, GST, OMT, AM3, CHS3 and F3H1 showed approximately 50-fold downregulation in the white flesh of Muscat Hamburg compared to the red flesh of Yan73. A correlation analysis between the accumulation of different types of anthocyanins and gene expression indicated that the cumulative expression of GST, F3′5′H, LDOX and MYBA1 was more closely associated with the acylated anthocyanins and the 3′5′-OH anthocyanins, while OMT and AM3 were more closely associated with the total anthocyanins and methoxylated anthocyanins. Therefore, the transcripts of OMT, AM3, GST, F3′5′H, LDOX and MYBA1 explained most of the variation in the amount and composition of anthocyanins in skin and flesh of Yan73. The data suggest that the specific localization of anthocyanins in the flesh tissue of Yan73 is most likely due to the tissue-specific expression of OMT, AM3, GST, F3′5′H, LDOX and MYBA1 in the flesh.

  14. Strengthening Triterpene Saponins Biosynthesis by Over-Expression of Farnesyl Pyrophosphate Synthase Gene and RNA Interference of Cycloartenol Synthase Gene in Panax notoginseng Cells

    Directory of Open Access Journals (Sweden)

    Yan Yang

    2017-04-01

    Full Text Available To conform to the multiple regulations of triterpene biosynthesis, the gene encoding farnesyl pyrophosphate synthase (FPS was transformed into Panax notoginseng (P. notoginseng cells in which RNA interference (RNAi of the cycloartenol synthase (CAS gene had been accomplished. Transgenic cell lines showed both higher expression levels of FPS and lower expression levels of CAS compared to the wild-type (WT cells. In the triterpene and phytosterol analysis, transgenic cell lines provided a higher accumulation of total triterpene saponins, and a lower amount of phytosterols in comparison with the WT cells. Compared with the cells in which RNAi of the CAS gene was achieved, the cells with simultaneously over-expressed FPS and silenced CAS showed higher triterpene contents. These results demonstrate that over-expression of FPS can break the rate-limiting reaction catalyzed by FPS in the triterpene saponins biosynthetic pathway; and inhibition of CAS expression can decrease the synthesis metabolic flux of the phytosterol branch. Thus, more precursors flow in the direction of triterpene synthesis, and ultimately promote the accumulation of P. notoginseng saponins. Meanwhile, silencing and over-expressing key enzyme genes simultaneously is more effective than just manipulating one gene in the regulation of saponin biosynthesis.

  15. Functional Analysis of Genes Involved in the Biosynthesis of Enterocin NKR-5-3B, a Novel Circular Bacteriocin.

    Science.gov (United States)

    Perez, Rodney H; Ishibashi, Naoki; Inoue, Tomoko; Himeno, Kohei; Masuda, Yoshimitsu; Sawa, Narukiko; Zendo, Takeshi; Wilaipun, Pongtep; Leelawatcharamas, Vichien; Nakayama, Jiro; Sonomoto, Kenji

    2016-01-15

    A putative biosynthetic gene cluster of the enterocin NKR-5-3B (Ent53B), a novel circular bacteriocin, was analyzed by sequencing the flanking regions around enkB, the Ent53B structural gene, using a fosmid library. A region approximately 9 kb in length was obtained, and the enkB1, enkB2, enkB3, and enkB4 genes, encoding putative biosynthetic proteins involved in the production, maturation, and secretion of Ent53B, were identified. We also determined the identity of proteins mediating self-immunity against the effects of Ent53B. Heterologous expression systems in various heterologous hosts, such as Enterococcus faecalis and Lactococcus lactis strains, were successfully established. The production and secretion of the mature Ent53B required the cooperative functions of five genes. Ent53B was produced only by those heterologous hosts that expressed protein products of the enkB, enkB1, enkB2, enkB3, and enkB4 genes. Moreover, self-immunity against the antimicrobial action of Ent53B was conferred by at least two independent mechanisms. Heterologous hosts harboring the intact enkB4 gene and/or a combination of intact enkB1 and enkB3 genes were immune to the inhibitory action of Ent53B. In addition to their potential application as food preservatives, circular bacteriocins are now considered possible alternatives to therapeutic antibiotics due to the exceptional stability conferred by their circular structure. The successful practical application of circular bacteriocins will become possible only if the molecular details of their biosynthesis are fully understood. The results of the present study offer a new perspective on the possible mechanism of circular bacteriocin biosynthesis. In addition, since some enterococcal strains are associated with pathogenicity, virulence, and drug resistance, the establishment of the first multigenus host heterologous production of Ent53B has very high practical significance, as it widens the scope of possible Ent53B applications

  16. Evolutionary rate patterns of the Gibberellin pathway genes

    Directory of Open Access Journals (Sweden)

    Zhang Fu-min

    2009-08-01

    Full Text Available Abstract Background Analysis of molecular evolutionary patterns of different genes within metabolic pathways allows us to determine whether these genes are subject to equivalent evolutionary forces and how natural selection shapes the evolution of proteins in an interacting system. Although previous studies found that upstream genes in the pathway evolved more slowly than downstream genes, the correlation between evolutionary rate and position of the genes in metabolic pathways as well as its implications in molecular evolution are still less understood. Results We sequenced and characterized 7 core structural genes of the gibberellin biosynthetic pathway from 8 representative species of the rice tribe (Oryzeae to address alternative hypotheses regarding evolutionary rates and patterns of metabolic pathway genes. We have detected significant rate heterogeneity among 7 GA pathway genes for both synonymous and nonsynonymous sites. Such rate variation is mostly likely attributed to differences of selection intensity rather than differential mutation pressures on the genes. Unlike previous argument that downstream genes in metabolic pathways would evolve more slowly than upstream genes, the downstream genes in the GA pathway did not exhibited the elevated substitution rate and instead, the genes that encode either the enzyme at the branch point (GA20ox or enzymes catalyzing multiple steps (KO, KAO and GA3ox in the pathway had the lowest evolutionary rates due to strong purifying selection. Our branch and codon models failed to detect signature of positive selection for any lineage and codon of the GA pathway genes. Conclusion This study suggests that significant heterogeneity of evolutionary rate of the GA pathway genes is mainly ascribed to differential constraint relaxation rather than the positive selection and supports the pathway flux theory that predicts that natural selection primarily targets enzymes that have the greatest control on fluxes.

  17. Next Generation Sequencing and Transcriptome Analysis Predicts Biosynthetic Pathway of Sennosides from Senna (Cassia angustifolia Vahl., a Non-Model Plant with Potent Laxative Properties.

    Directory of Open Access Journals (Sweden)

    Nagaraja Reddy Rama Reddy

    Full Text Available Senna (Cassia angustifolia Vahl. is a world's natural laxative medicinal plant. Laxative properties are due to sennosides (anthraquinone glycosides natural products. However, little genetic information is available for this species, especially concerning the biosynthetic pathways of sennosides. We present here the transcriptome sequencing of young and mature leaf tissue of Cassia angustifolia using Illumina MiSeq platform that resulted in a total of 6.34 Gb of raw nucleotide sequence. The sequence assembly resulted in 42230 and 37174 transcripts with an average length of 1119 bp and 1467 bp for young and mature leaf, respectively. The transcripts were annotated using NCBI BLAST with 'green plant database (txid 33090', Swiss Prot, Kyoto Encylcopedia of Genes & Genomes (KEGG, Cluster of Orthologous Gene (COG and Gene Ontology (GO. Out of the total transcripts, 40138 (95.0% and 36349 (97.7% from young and mature leaf, respectively, were annotated by BLASTX against green plant database of NCBI. We used InterProscan to see protein similarity at domain level, a total of 34031 (young leaf and 32077 (mature leaf transcripts were annotated against the Pfam domains. All transcripts from young and mature leaf were assigned to 191 KEGG pathways. There were 166 and 159 CDS, respectively, from young and mature leaf involved in metabolism of terpenoids and polyketides. Many CDS encoding enzymes leading to biosynthesis of sennosides were identified. A total of 10,763 CDS differentially expressing in both young and mature leaf libraries of which 2,343 (21.7% CDS were up-regulated in young compared to mature leaf. Several differentially expressed genes found functionally associated with sennoside biosynthesis. CDS encoding for many CYPs and TF families were identified having probable roles in metabolism of primary as well as secondary metabolites. We developed SSR markers for molecular breeding of senna. We have identified a set of putative genes involved in

  18. Next Generation Sequencing and Transcriptome Analysis Predicts Biosynthetic Pathway of Sennosides from Senna (Cassia angustifolia Vahl.), a Non-Model Plant with Potent Laxative Properties.

    Science.gov (United States)

    Rama Reddy, Nagaraja Reddy; Mehta, Rucha Harishbhai; Soni, Palak Harendrabhai; Makasana, Jayanti; Gajbhiye, Narendra Athamaram; Ponnuchamy, Manivel; Kumar, Jitendra

    2015-01-01

    Senna (Cassia angustifolia Vahl.) is a world's natural laxative medicinal plant. Laxative properties are due to sennosides (anthraquinone glycosides) natural products. However, little genetic information is available for this species, especially concerning the biosynthetic pathways of sennosides. We present here the transcriptome sequencing of young and mature leaf tissue of Cassia angustifolia using Illumina MiSeq platform that resulted in a total of 6.34 Gb of raw nucleotide sequence. The sequence assembly resulted in 42230 and 37174 transcripts with an average length of 1119 bp and 1467 bp for young and mature leaf, respectively. The transcripts were annotated using NCBI BLAST with 'green plant database (txid 33090)', Swiss Prot, Kyoto Encylcopedia of Genes & Genomes (KEGG), Cluster of Orthologous Gene (COG) and Gene Ontology (GO). Out of the total transcripts, 40138 (95.0%) and 36349 (97.7%) from young and mature leaf, respectively, were annotated by BLASTX against green plant database of NCBI. We used InterProscan to see protein similarity at domain level, a total of 34031 (young leaf) and 32077 (mature leaf) transcripts were annotated against the Pfam domains. All transcripts from young and mature leaf were assigned to 191 KEGG pathways. There were 166 and 159 CDS, respectively, from young and mature leaf involved in metabolism of terpenoids and polyketides. Many CDS encoding enzymes leading to biosynthesis of sennosides were identified. A total of 10,763 CDS differentially expressing in both young and mature leaf libraries of which 2,343 (21.7%) CDS were up-regulated in young compared to mature leaf. Several differentially expressed genes found functionally associated with sennoside biosynthesis. CDS encoding for many CYPs and TF families were identified having probable roles in metabolism of primary as well as secondary metabolites. We developed SSR markers for molecular breeding of senna. We have identified a set of putative genes involved in various

  19. Identification of the First Riboflavin Catabolic Gene Cluster Isolated from Microbacterium maritypicum G10*

    Science.gov (United States)

    Xu, Hui; Chakrabarty, Yindrila; Philmus, Benjamin; Mehta, Angad P.; Bhandari, Dhananjay; Hohmann, Hans-Peter; Begley, Tadhg P.

    2016-01-01

    Riboflavin is a common cofactor, and its biosynthetic pathway is well characterized. However, its catabolic pathway, despite intriguing hints in a few distinct organisms, has never been established. This article describes the isolation of a Microbacterium maritypicum riboflavin catabolic strain, and the cloning of the riboflavin catabolic genes. RcaA, RcaB, RcaD, and RcaE were overexpressed and biochemically characterized as riboflavin kinase, riboflavin reductase, ribokinase, and riboflavin hydrolase, respectively. Based on these activities, a pathway for riboflavin catabolism is proposed. PMID:27590337

  20. Comprehensive annotation of secondary metabolite biosynthetic genes and gene clusters of Aspergillus nidulans, A. fumigatus, A. niger and A. oryzae

    OpenAIRE

    Inglis, Diane O; Binkley, Jonathan; Skrzypek, Marek S; Arnaud, Martha B; Cerqueira, Gustavo C; Shah, Prachi; Wymore, Farrell; Wortman, Jennifer R; Sherlock, Gavin

    2013-01-01

    Background Secondary metabolite production, a hallmark of filamentous fungi, is an expanding area of research for the Aspergilli. These compounds are potent chemicals, ranging from deadly toxins to therapeutic antibiotics to potential anti-cancer drugs. The genome sequences for multiple Aspergilli have been determined, and provide a wealth of predictive information about secondary metabolite production. Sequence analysis and gene overexpression strategies have enabled the discovery of novel s...

  1. Spiroketals of Pestalotiopsis fici provide evidence for a biosynthetic hypothesis involving diversified Diels-Alder reaction cascades.

    Science.gov (United States)

    Liu, Ling; Li, Yan; Li, Li; Cao, Ya; Guo, Liangdong; Liu, Gang; Che, Yongsheng

    2013-04-05

    Chloropestolides B-G (1-6), six new metabolites featuring the chlorinated spiro[benzo[d][1,3]dioxine-2,7'-bicyclo[2.2.2]octane]-4,8'-dione (1-3) and spiro[benzo[d][1,3]dioxine-2,1'-naphthalene]-2',4-dione (4-6) skeletons, and their putative biosynthetic precursor dechloromaldoxin (7) were isolated from the scale-up fermentation cultures of the plant endophytic fungus Pestalotiopsis fici . The structures of 1-7 were determined mainly by NMR experiments. The absolute configurations of 1-3 were deduced by analogy to the previously isolated metabolites from the same fungus (9 and 13-18), whereas those of 4, 5, and 7 were assigned by electronic circular dichroism (ECD) calculations. Structurally, the spiroketal skeletons found in 1-3 and 4-6 could be derived from 2,6-dihydroxy-4-methylbenzoic acid with chlorinated bicyclo[2.2.2]oct-2-en-5-one and 4a,5,8,8a-tetrahydronaphthalen-2(1H)-one, respectively. Biogenetically, compounds 1-6 were derived from the same Diels-Alder precursors as the previously isolated 9 and 12-18. In addition, compounds 2 and 3 were proposed as the biosynthetic intermediates of 17 and 16, respectively. Compound 1 was cytotoxic to three human tumor cell lines.

  2. Biosynthetic hydrogels--studies on chemical and physical characteristics on long-term cellular response for tissue engineering.

    Science.gov (United States)

    Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

    2014-07-01

    Biosynthetic hydrogels can meet the drawbacks caused by natural and synthetic ones for biomedical applications. In the current article we present a novel biosynthetic alginate-poly(propylene fumarate) copolymer based chemically crosslinked hydrogel scaffolds for cardiac tissue engineering applications. Partially crosslinked PA hydrogel and fully cross linked PA-A hydrogel scaffolds were prepared. The influence of chemical and physical (morphology and architecture of hydrogel) characteristics on the long term cellular response was studied. Both these hydrogels were cytocompatible and showed no genotoxicity upon contact with fibroblast cells. Both PA and PA-A were able to resist deleterious effects of reactive oxygen species and sustain the viability of L929 cells. The hydrogel incubated oxidative stress induced cells were capable of maintaining the intra cellular reduced glutathione (GSH) expression to the normal level confirmed their protective effect. Relatively the PA hydrogel was found to be unstable in the cell culture medium. The PA-A hydrogel was able to withstand appreciable cyclic stretching. The cyclic stretching introduced complex macro and microarchitectural features with interconnected pores and more structured bound water which would provide long-term viability of around 250% after the 24th day of culture. All these qualities make PA-A hydrogel form a potent candidate for cardiac tissue engineering. © 2013 Wiley Periodicals, Inc.

  3. Water splitting-biosynthetic system with CO₂ reduction efficiencies exceeding photosynthesis.

    Science.gov (United States)

    Liu, Chong; Colón, Brendan C; Ziesack, Marika; Silver, Pamela A; Nocera, Daniel G

    2016-06-03

    Artificial photosynthetic systems can store solar energy and chemically reduce CO2 We developed a hybrid water splitting-biosynthetic system based on a biocompatible Earth-abundant inorganic catalyst system to split water into molecular hydrogen and oxygen (H2 and O2) at low driving voltages. When grown in contact with these catalysts, Ralstonia eutropha consumed the produced H2 to synthesize biomass and fuels or chemical products from low CO2 concentration in the presence of O2 This scalable system has a CO2 reduction energy efficiency of ~50% when producing bacterial biomass and liquid fusel alcohols, scrubbing 180 grams of CO2 per kilowatt-hour of electricity. Coupling this hybrid device to existing photovoltaic systems would yield a CO2 reduction energy efficiency of ~10%, exceeding that of natural photosynthetic systems. Copyright © 2016, American Association for the Advancement of Science.

  4. Expression Profiling of Glucosinolate Biosynthetic Genes in Brassica oleracea L. var. capitata Inbred Lines Reveals Their Association with Glucosinolate Content

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    Arif Hasan Khan Robin

    2016-06-01

    Full Text Available Glucosinolates are the biochemical compounds that provide defense to plants against pathogens and herbivores. In this study, the relative expression level of 48 glucosinolate biosynthesis genes was explored in four morphologically-different cabbage inbred lines by qPCR analysis. The content of aliphatic and indolic glucosinolate molecules present in those cabbage lines was also estimated by HPLC analysis. The possible association between glucosinolate accumulation and related gene expression level was explored by principal component analysis (PCA. The genotype-dependent variation in the relative expression level of different aliphatic and indolic glucosinolate biosynthesis genes is the novel result of this study. A total of eight different types of glucosinolates, including five aliphatic and three indolic glucosinolates, was detected in four cabbage lines. Three inbred lines BN3383, BN4059 and BN4072 had no glucoraphanin, sinigrin and gluconapin detected, but the inbred line BN3273 had these three aliphatic glucosinolate compounds. PCA revealed that a higher expression level of ST5b genes and lower expression of GSL-OH was associated with the accumulation of these three aliphatic glucosinolate compounds. PCA further revealed that comparatively higher accumulation of neoglucobrassicin in the inbred line, BN4072, was associated with a high level of expression of MYB34 (Bol017062 and CYP81F1 genes. The Dof1 and IQD1 genes probably trans-activated the genes related to biosynthesis of glucoerucin and methoxyglucobrassicin for their comparatively higher accumulation in the BN4059 and BN4072 lines compared to the other two lines, BN3273 and BN3383. A comparatively higher progoitrin level in BN3273 was probably associated with the higher expression level of the GSL-OH gene. The cabbage inbred line BN3383 accounted for the significantly higher relative expression level for the 12 genes out of 48, but this line had comparatively lower total

  5. Selection and validation of reference genes for quantitative gene expression studies in Erythroxylum coca [v1; ref status: indexed, http://f1000r.es/y1

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    Teresa Docimo

    2013-02-01

    Full Text Available Real-time quantitative PCR is a powerful technique for the investigation of comparative gene expression, but its accuracy and reliability depend on the reference genes used as internal standards. Only genes that show a high level of expression stability are suitable for use as reference genes, and these must be identified on a case-by-case basis. Erythroxylum coca produces and accumulates high amounts of the pharmacologically active tropane alkaloid cocaine (especially in the leaves, and is an emerging model for the investigation of tropane alkaloid biosynthesis. The identification of stable internal reference genes for this species is important for its development as a model species, and would enable comparative analysis of candidate biosynthetic genes in the different tissues of the coca plant. In this study, we evaluated the expression stability of nine candidate reference genes in E. coca (Ec6409, Ec10131, Ec11142, Actin, APT2, EF1α, TPB1, Pex4, Pp2aa3. The expression of these genes was measured in seven tissues (flowers, stems, roots and four developmental leaf stages and the stability of expression was assessed using three algorithms (geNorm, NormFinder and BestKeeper. From our results we conclude that Ec10131 and TPB1 are the most appropriate internal reference genes in leaves (where the majority of cocaine is produced, while Ec10131 and Ec6409 are the most suitable internal reference genes across all of the tissues tested.

  6. Identification and expression analysis of glucosinolate biosynthetic genes and estimation of glucosinolate contents in edible organs of Brassica oleracea subspecies.

    Science.gov (United States)

    Yi, Go-Eun; Robin, Arif Hasan Khan; Yang, Kiwoung; Park, Jong-In; Kang, Jong-Goo; Yang, Tae-Jin; Nou, Ill-Sup

    2015-07-20

    Glucosinolates are anti-carcinogenic, anti-oxidative biochemical compounds that defend plants from insect and microbial attack. Glucosinolates are abundant in all cruciferous crops, including all vegetable and oilseed Brassica species. Here, we studied the expression of glucosinolate biosynthesis genes and determined glucosinolate contents in the edible organs of a total of 12 genotypes of Brassica oleracea: three genotypes each from cabbage, kale, kohlrabi and cauliflower subspecies. Among the 81 genes analyzed by RT-PCR, 19 are transcription factor-related, two different sets of 25 genes are involved in aliphatic and indolic biosynthesis pathways and the rest are breakdown-related. The expression of glucosinolate-related genes in the stems of kohlrabi was remarkably different compared to leaves of cabbage and kale and florets of cauliflower as only eight genes out of 81 were expressed in the stem tissues of kohlrabi. In the stem tissue of kohlrabi, only one aliphatic transcription factor-related gene, Bol036286 (MYB28) and one indolic transcription factor-related gene, Bol030761 (MYB51), were expressed. The results indicated the expression of all genes is not essential for glucosinolate biosynthesis. Using HPLC analysis, a total of 16 different types of glucosinolates were identified in four subspecies, nine of them were aliphatic, four of them were indolic and one was aromatic. Cauliflower florets measured the highest number of 14 glucosinolates. Among the aliphatic glucosinolates, only gluconapin was found in the florets of cauliflower. Glucoiberverin and glucobrassicanapin contents were the highest in the stems of kohlrabi. The indolic methoxyglucobrassicin and aromatic gluconasturtiin accounted for the highest content in the florets of cauliflower. A further detailed investigation and analyses is required to discern the precise roles of each of the genes for aliphatic and indolic glucosinolate biosynthesis in the edible organs.

  7. Identification and Expression Analysis of Glucosinolate Biosynthetic Genes and Estimation of Glucosinolate Contents in Edible Organs of Brassica oleracea Subspecies

    Directory of Open Access Journals (Sweden)

    Go-Eun Yi

    2015-07-01

    Full Text Available Glucosinolates are anti-carcinogenic, anti-oxidative biochemical compounds that defend plants from insect and microbial attack. Glucosinolates are abundant in all cruciferous crops, including all vegetable and oilseed Brassica species. Here, we studied the expression of glucosinolate biosynthesis genes and determined glucosinolate contents in the edible organs of a total of 12 genotypes of Brassica oleracea: three genotypes each from cabbage, kale, kohlrabi and cauliflower subspecies. Among the 81 genes analyzed by RT-PCR, 19 are transcription factor-related, two different sets of 25 genes are involved in aliphatic and indolic biosynthesis pathways and the rest are breakdown-related. The expression of glucosinolate-related genes in the stems of kohlrabi was remarkably different compared to leaves of cabbage and kale and florets of cauliflower as only eight genes out of 81 were expressed in the stem tissues of kohlrabi. In the stem tissue of kohlrabi, only one aliphatic transcription factor-related gene, Bol036286 (MYB28 and one indolic transcription factor-related gene, Bol030761 (MYB51, were expressed. The results indicated the expression of all genes is not essential for glucosinolate biosynthesis. Using HPLC analysis, a total of 16 different types of glucosinolates were identified in four subspecies, nine of them were aliphatic, four of them were indolic and one was aromatic. Cauliflower florets measured the highest number of 14 glucosinolates. Among the aliphatic glucosinolates, only gluconapin was found in the florets of cauliflower. Glucoiberverin and glucobrassicanapin contents were the highest in the stems of kohlrabi. The indolic methoxyglucobrassicin and aromatic gluconasturtiin accounted for the highest content in the florets of cauliflower. A further detailed investigation and analyses is required to discern the precise roles of each of the genes for aliphatic and indolic glucosinolate biosynthesis in the edible organs.

  8. Characterization of the gene encoding serine acetyltransferase, a regulated enzyme of cysteine biosynthesis from the protist parasites Entamoeba histolytica and Entamoeba dispar. Regulation and possible function of the cysteine biosynthetic pathway in Entamoeba.

    Science.gov (United States)

    Nozaki, T; Asai, T; Sanchez, L B; Kobayashi, S; Nakazawa, M; Takeuchi, T

    1999-11-05

    The enteric protist parasites Entamoeba histolytica and Entamoeba dispar possess a cysteine biosynthetic pathway, unlike their mammalian host, and are capable of de novo production of L-cysteine. We cloned and characterized cDNAs that encode the regulated enzyme serine acetyltransferase (SAT) in this pathway from these amoebae by genetic complementation of a cysteine-auxotrophic Escherichia coli strain with the amoebic cDNA libraries. The deduced amino acid sequences of the amoebic SATs exhibited, within the most conserved region, 36-52% identities with the bacterial and plant SATs. The amoebic SATs contain a unique insertion of eight amino acids, also found in the corresponding region of a plasmid-encoded SAT from Synechococcus sp., which showed the highest overall identities to the amoebic SATs. Phylogenetic reconstruction also revealed a close kinship of the amoebic SATs with cyanobacterial SATs. Biochemical characterization of the recombinant E. histolytica SAT revealed several enzymatic features that distinguished the amoebic enzyme from the bacterial and plant enzymes: 1) inhibition by L-cysteine in a competitive manner with L-serine; 2) inhibition by L-cystine; and 3) no association with cysteine synthase. Genetically engineered amoeba strains that overproduced cysteine synthase and SAT were created. The cysteine synthase-overproducing amoebae had a higher level of cysteine synthase activity and total thiol content and revealed increased resistance to hydrogen peroxide. These results indicate that the cysteine biosynthetic pathway plays an important role in antioxidative defense of these enteric parasites.

  9. Application of a Colorimetric Assay to Identify Putative Ribofuranosylaminobenzene 5'-Phosphate Synthase Genes Expressed with Activity in Escherichia coli

    OpenAIRE

    Bechard, Matthew E.; Chhatwal, Sonya; Garcia, Rosemarie E.; Rasche, Madeline E.

    2003-01-01

    Tetrahydromethanopterin (H4MPT) is a tetrahydrofolate analog originally discovered in methanogenic archaea, but later found in other archaea and bacteria. The extent to which H4MPT occurs among living organisms is unknown. The key enzyme which distinguishes the biosynthetic pathways of H4MPT and tetrahydrofolate is ribofuranosylaminobenzene 5'-phosphate synthase (RFAP synthase). Given the importance of RFAP synthase in H4MPT biosynthesis, the identification of putative RFAP synthase genes and...

  10. Di-(2 ethylhexyl phthalate and flutamide alter gene expression in the testis of immature male rats

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    Yu Frank H

    2009-09-01

    Full Text Available Abstract We previously demonstrated that the androgenic and anti-androgenic effects of endocrine disruptors (EDs alter reproductive function and exert distinct effects on developing male reproductive organs. To further investigate these effects, we used an immature rat model to examine the effects of di-(2 ethylhexyl phthalate (DEHP and flutamide (Flu on the male reproductive system. Immature male SD rats were treated daily with DEHP and Flu on postnatal days (PNDs 21 to 35, in a dose-dependent manner. As results, the weights of the testes, prostate, and seminal vesicle and anogenital distances (AGD decreased significantly in response to high doses of DEHP or Flu. Testosterone (T levels significantly decreased in all DEHP- treated groups, whereas luteinizing hormone (LH plasma levels were not altered by any of the two treatments at PND 36. However, treatment with DEHP or Flu induced histopathological changes in the testes, wherein degeneration and disorders of Leydig cells, germ cells and dilatation of tubular lumen were observed in a dose-dependent manner. Conversely, hyperplasia and denseness of Leydig, Sertoli and germ cells were observed in rats given with high doses of Flu. The results by cDNA microarray analysis indicated that 1,272 genes were up-regulated by more than two-fold, and 1,969 genes were down-regulated in response to DEHP, Flu or both EDs. These genes were selected based on their markedly increased or decreased expression levels. These genes have been also classified on the basis of gene ontology (e.g., steroid hormone biosynthetic process, regulation of transcription, signal transduction, metabolic process, biosynthetic process.... Significant decreases in gene expression were observed in steroidogenic genes (i.e., Star, Cyp11a1 and Hsd3b. In addition, the expression of a common set of target genes, including CaBP1, Vav2, Plcd1, Lhx1 and Isoc1, was altered following exposure to EDs, suggesting that they may be marker genes to

  11. Non-aflatoxigenicity of commercial Aspergillus oryzae strains due to genetic defects compared to aflatoxigenic Aspergillus flavus.

    Science.gov (United States)

    Tao, Lin; Chung, Soo Hyun

    2014-08-01

    Aspergillus oryzae is generally recognized as safe, but it is closely related to A. flavus in morphology and genetic characteristics. In this study, we tested the aflatoxigenicity and genetic analysis of nine commercial A. oryzae strains that were used in Korean soybean fermented products. Cultural and HPLC analyses showed that none of the commercial strains produced detectable amount of aflatoxins. According to the molecular analysis of 17 genes in the aflatoxin (AF) biosynthetic pathway, the commercial strains could be classified into three groups. The group I strains contained all the 17 AF biosynthetic genes tested in this study; the group II strains deleted nine AF biosynthetic genes and possessed eight genes, including aflG, aflI, aflK, aflL, aflM, aflO, aflP, and aflQ; the group III strains only had six AF biosynthetic genes, including aflG, aflI, aflK, aflO, aflP, and aflQ. With the reverse transcription polymerase chain reaction, the group I A. oryzae strains showed no expression of aflG, aflQ and/or aflM genes, which resulted in the lack of AF-producing ability. Group II and group III strains could not produce AF owing to the deletion of more than half of the AF biosynthetic genes. In addition, the sequence data of polyketide synthase A (pksA) of group I strains of A. oryzae showed that there were three point mutations (two silent mutations and one missense mutation) compared with aflatoxigenic A. flavus used as the positive control in this study.

  12. Identification of the First Riboflavin Catabolic Gene Cluster Isolated from Microbacterium maritypicum G10.

    Science.gov (United States)

    Xu, Hui; Chakrabarty, Yindrila; Philmus, Benjamin; Mehta, Angad P; Bhandari, Dhananjay; Hohmann, Hans-Peter; Begley, Tadhg P

    2016-11-04

    Riboflavin is a common cofactor, and its biosynthetic pathway is well characterized. However, its catabolic pathway, despite intriguing hints in a few distinct organisms, has never been established. This article describes the isolation of a Microbacterium maritypicum riboflavin catabolic strain, and the cloning of the riboflavin catabolic genes. RcaA, RcaB, RcaD, and RcaE were overexpressed and biochemically characterized as riboflavin kinase, riboflavin reductase, ribokinase, and riboflavin hydrolase, respectively. Based on these activities, a pathway for riboflavin catabolism is proposed. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. A Gene Cluster for Biosynthesis of Mannosylerythritol Lipids Consisted of 4-O-β-D-Mannopyranosyl-(2R,3S-Erythritol as the Sugar Moiety in a Basidiomycetous Yeast Pseudozyma tsukubaensis.

    Directory of Open Access Journals (Sweden)

    Azusa Saika

    Full Text Available Mannosylerythritol lipids (MELs belong to the glycolipid biosurfactants and are produced by various fungi. The basidiomycetous yeast Pseudozyma tsukubaensis produces diastereomer type of MEL-B, which contains 4-O-β-D-mannopyranosyl-(2R,3S-erythritol (R-form as the sugar moiety. In this respect it differs from conventional type of MELs, which contain 4-O-β-D-mannopyranosyl-(2S,3R-erythritol (S-form as the sugar moiety. While the biosynthetic gene cluster for conventional type of MELs has been previously identified in Ustilago maydis and Pseudozyma antarctica, the genetic basis for MEL biosynthesis in P. tsukubaensis is unknown. Here, we identified a gene cluster involved in MEL biosynthesis in P. tsukubaensis. Among these genes, PtEMT1, which encodes erythritol/mannose transferase, had greater than 69% identity with homologs from strains in the genera Ustilago, Melanopsichium, Sporisorium and Pseudozyma. However, phylogenetic analysis placed PtEMT1p in a separate clade from the other proteins. To investigate the function of PtEMT1, we introduced the gene into a P. antarctica mutant strain, ΔPaEMT1, which lacks MEL biosynthesis ability owing to the deletion of PaEMT1. Using NMR spectroscopy, we identified the biosynthetic product as MEL-A with altered sugar conformation. These results indicate that PtEMT1p catalyzes the sugar conformation of MELs. This is the first report of a gene cluster for the biosynthesis of diastereomer type of MEL.

  14. Regulation of FA and TAG biosynthesis pathway genes in endosperms and embryos of high and low oil content genotypes of Jatropha curcas L.

    Science.gov (United States)

    Sood, Archit; Chauhan, Rajinder Singh

    2015-09-01

    The rising demand for biofuels has raised concerns about selecting alternate and promising renewable energy crops which do not compete with food supply. Jatropha (Jatropha curcas L.), a non-edible energy crop of the family euphorbiaceae, has the potential of providing biodiesel feedstock due to the presence of high proportion of unsaturated fatty acids (75%) in seed oil which is mainly accumulated in endosperm and embryo. The molecular basis of seed oil biosynthesis machinery has been studied in J. curcas, however, what genetic differences contribute to differential oil biosynthesis and accumulation in genotypes varying for oil content is poorly understood. We investigated expression profile of 18 FA and TAG biosynthetic pathway genes in different developmental stages of embryo and endosperm from high (42%) and low (30%) oil content genotypes grown at two geographical locations. Most of the genes showed relatively higher expression in endosperms of high oil content genotype, whereas no significant difference was observed in endosperms versus embryos of low oil content genotype. The promoter regions of key genes from FA and TAG biosynthetic pathways as well as other genes implicated in oil accumulation were analyzed for regulatory elements and transcription factors specific to oil or lipid accumulation in plants such as Dof, CBF (LEC1), SORLIP, GATA and Skn-1_motif etc. Identification of key genes from oil biosynthesis and regulatory elements specific to oil deposition will be useful not only in dissecting the molecular basis of high oil content but also improving seed oil content through transgenic or molecular breeding approaches. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. A Root-Preferential DFR-Like Gene Encoding Dihydrokaempferol Reductase Involved in Anthocyanin Biosynthesis of Purple-Fleshed Sweet Potato.

    Science.gov (United States)

    Liu, Xiaoqiang; Xiang, Min; Fan, Yufang; Yang, Chunxian; Zeng, Lingjiang; Zhang, Qitang; Chen, Min; Liao, Zhihua

    2017-01-01

    Purple-fleshed sweet potato is good for health due to rich anthocyanins in tubers. Although the anthocyanin biosynthetic pathway is well understood in up-ground organs of plants, the knowledge on anthocyanin biosynthesis in underground tubers is limited. In the present study, we isolated and functionally characterized a root-preferential gene encoding dihydrokaempferol reductase ( IbDHKR ) from purple-fleshed sweet potato. IbDHKR showed highly similarity with the reported dihydroflavonol reductases in other plant species at the sequence levels and the NADPH-binding motif and the substrate-binding domain were also found in IbDHKR. The tissue profile showed that IbDHKR was expressed in all the tested organs, but with much higher level in tuber roots. The expression level of IbDHKR was consistent with the anthocyanin content in sweet potato organs, suggesting that tuber roots were the main organs to synthesize anthocyanins. The recombinant 44 kD IbDHKR was purified and fed by three different dihydroflavonol substrates including dihydrokaempferol (DHK), dihydroquerctin, and dihydromyrecetin. The substrate feeding assay indicated that only DHK could be accepted as substrate by IbDHKR, which was reduced to leucopelargonidin confirmed by LC-MS. Finally, IbDHKR was overexpressed in transgenic tobacco. The IbDHKR-overexpression tobacco corolla was more highly pigmented and contained higher level of anthocyanins than the wild-type tobacco corolla. In summary, IbDHKR was a root-preferential gene involved in anthocyanin biosynthesis and its encoding protein, specifically catalyzing DHK reduction to yield leucopelargonidin, was a candidate gene for engineering anthocyanin biosynthetic pathway.

  16. Biosynthetic origin of the isoprene units in chromenes of Piper aduncum (Piperaceae)

    International Nuclear Information System (INIS)

    Leite, Ana C.; Lopes, Adriana A.; Bolzani, Vanderlan da S.; Furlan, Maysa; Kato, Massuo J.

    2007-01-01

    Metabolic studies involving the incorporation of [1- 13 C]-D-glucose into intact leaves of Piper aduncum (Piperaceae) have indicated that both the mevalonate (MVA) and the pyruvate-triose (MEP) non-mevalonate pathways are implicated in the biosynthesis of isoprene moieties present in methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate (1) and methyl 2,2-dimethyl-8-(3'-methyl- 2'-butenyl)-2H-1-chromene-6-carboxylate (2). The pattern of incorporation of label from [1- 13 C]-D-glucose into these chromenes was determined by quantitative 13 C NMR spectroscopy. The results confirmed that biosynthetic compartment of 1 and 2 could either be the plastid and/ or the cytosol or, possibly, an additional compartment such as the plastid inter-membrane space. (author)

  17. Adaptations to High Salt in a Halophilic Protist: Differential Expression and Gene Acquisitions through Duplications and Gene Transfers

    Science.gov (United States)

    Harding, Tommy; Roger, Andrew J.; Simpson, Alastair G. B.

    2017-01-01

    The capacity of halophiles to thrive in extreme hypersaline habitats derives partly from the tight regulation of ion homeostasis, the salt-dependent adjustment of plasma membrane fluidity, and the increased capability to manage oxidative stress. Halophilic bacteria, and archaea have been intensively studied, and substantial research has been conducted on halophilic fungi, and the green alga Dunaliella. By contrast, there have been very few investigations of halophiles that are phagotrophic protists, i.e., protozoa. To gather fundamental knowledge about salt adaptation in these organisms, we studied the transcriptome-level response of Halocafeteria seosinensis (Stramenopiles) grown under contrasting salinities. We provided further evolutionary context to our analysis by identifying genes that underwent recent duplications. Genes that were highly responsive to salinity variations were involved in stress response (e.g., chaperones), ion homeostasis (e.g., Na+/H+ transporter), metabolism and transport of lipids (e.g., sterol biosynthetic genes), carbohydrate metabolism (e.g., glycosidases), and signal transduction pathways (e.g., transcription factors). A significantly high proportion (43%) of duplicated genes were also differentially expressed, accentuating the importance of gene expansion in adaptation by H. seosinensis to high salt environments. Furthermore, we found two genes that were lateral acquisitions from bacteria, and were also highly up-regulated and highly expressed at high salt, suggesting that this evolutionary mechanism could also have facilitated adaptation to high salt. We propose that a transition toward high-salt adaptation in the ancestors of H. seosinensis required the acquisition of new genes via duplication, and some lateral gene transfers (LGTs), as well as the alteration of transcriptional programs, leading to increased stress resistance, proper establishment of ion gradients, and modification of cell structure properties like membrane

  18. Adaptations to High Salt in a Halophilic Protist: Differential Expression and Gene Acquisitions through Duplications and Gene Transfers

    Directory of Open Access Journals (Sweden)

    Tommy Harding

    2017-05-01

    Full Text Available The capacity of halophiles to thrive in extreme hypersaline habitats derives partly from the tight regulation of ion homeostasis, the salt-dependent adjustment of plasma membrane fluidity, and the increased capability to manage oxidative stress. Halophilic bacteria, and archaea have been intensively studied, and substantial research has been conducted on halophilic fungi, and the green alga Dunaliella. By contrast, there have been very few investigations of halophiles that are phagotrophic protists, i.e., protozoa. To gather fundamental knowledge about salt adaptation in these organisms, we studied the transcriptome-level response of Halocafeteria seosinensis (Stramenopiles grown under contrasting salinities. We provided further evolutionary context to our analysis by identifying genes that underwent recent duplications. Genes that were highly responsive to salinity variations were involved in stress response (e.g., chaperones, ion homeostasis (e.g., Na+/H+ transporter, metabolism and transport of lipids (e.g., sterol biosynthetic genes, carbohydrate metabolism (e.g., glycosidases, and signal transduction pathways (e.g., transcription factors. A significantly high proportion (43% of duplicated genes were also differentially expressed, accentuating the importance of gene expansion in adaptation by H. seosinensis to high salt environments. Furthermore, we found two genes that were lateral acquisitions from bacteria, and were also highly up-regulated and highly expressed at high salt, suggesting that this evolutionary mechanism could also have facilitated adaptation to high salt. We propose that a transition toward high-salt adaptation in the ancestors of H. seosinensis required the acquisition of new genes via duplication, and some lateral gene transfers (LGTs, as well as the alteration of transcriptional programs, leading to increased stress resistance, proper establishment of ion gradients, and modification of cell structure properties like

  19. Molecular characterization of genes encoding leucoanthocyanidin reductase involved in proanthocyanidin biosynthesis in apple

    Directory of Open Access Journals (Sweden)

    Yuepeng eHan

    2015-04-01

    Full Text Available Proanthocyanidins (PAs are the major component of phenolics in apple, but mechanisms involved in PA biosynthesis remain unclear. Here, the relationship between the PA biosynthesis and the expression of genes encoding leucoanthocyanidin reductase (LAR and anthocyanidin reductase (ANR was investigated in fruit skin of one apple cultivar and three crabapples. Transcript levels of LAR1 and ANR2 genes were significantly correlated with the contents of catechin and epicatechin, respectively, which suggests their active roles in PA synthesis. Surprisingly, transcript levels for both LAR1 and LAR2 genes were almost undetectable in two crabapples that accumulated both flavan-3-ols and PAs. This contradicts the previous finding that LAR1 gene is a strong candidate regulating the accumulation of metabolites such as epicatechin and PAs in apple. Ectopic expression of apple MdLAR1 gene in tobacco suppresses expression of the late genes in anthocyanin biosynthetic pathway, resulting in loss of anthocyanin in flowers. Interestingly, a decrease in PA biosynthesis was also observed in flowers of transgenic tobacco plants overexpressing the MdLAR1 gene, which could be attributed to decreased expression of both the NtANR1 and NtANR2 genes. Our study not only confirms the in vivo function of apple LAR1 gene, but it is also helpful for understanding the mechanism of PA biosynthesis.

  20. Changes in Macrophage Gene Expression Associated with Leishmania (Viannia braziliensis Infection.

    Directory of Open Access Journals (Sweden)

    Clemencia Ovalle-Bracho

    Full Text Available Different Leishmania species cause distinct clinical manifestations of the infectious disease leishmaniasis. It is fundamentally important to understand the mechanisms governing the interaction between Leishmania and its host cell. Little is known about this interaction between Leishmania (Viannia braziliensis and human macrophages. In this study, we aimed to identify differential gene expression between non-infected and L. (V braziliensis-infected U937-derived macrophages. We deployed a whole human transcriptome microarray analysis using 72 hours post-infection samples and compared those samples with their non-infected counterparts. We found that 218 genes were differentially expressed between infected and non-infected macrophages. A total of 71.6% of these genes were down-regulated in the infected macrophages. Functional enrichment analyses identified the steroid and sterol/cholesterol biosynthetic processes between regulatory networks down-regulated in infected macrophages. RT-qPCR further confirmed this down-regulation in genes belonging to these pathways. These findings contrast with those from studies involving other Leishmania species at earlier infection stages, where gene up-regulation for this metabolic pathway has been reported. Sterol biosynthesis could be an important biological process associated with the expression profile of macrophages infected by L. (V. braziliensis. Differential transcriptional results suggest a negative regulation of the genetic regulatory network involved in cholesterol biosynthesis.

  1. The PIN gene family in cotton (Gossypium hirsutum): genome-wide identification and gene expression analyses during root development and abiotic stress responses.

    Science.gov (United States)

    He, Peng; Zhao, Peng; Wang, Limin; Zhang, Yuzhou; Wang, Xiaosi; Xiao, Hui; Yu, Jianing; Xiao, Guanghui

    2017-07-03

    Cell elongation and expansion are significant contributors to plant growth and morphogenesis, and are often regulated by environmental cues and endogenous hormones. Auxin is one of the most important phytohormones involved in the regulation of plant growth and development and plays key roles in plant cell expansion and elongation. Cotton fiber cells are a model system for studying cell elongation due to their large size. Cotton is also the world's most utilized crop for the production of natural fibers for textile and garment industries, and targeted expression of the IAA biosynthetic gene iaaM increased cotton fiber initiation. Polar auxin transport, mediated by PIN and AUX/LAX proteins, plays a central role in the control of auxin distribution. However, very limited information about PIN-FORMED (PIN) efflux carriers in cotton is known. In this study, 17 PIN-FORMED (PIN) efflux carrier family members were identified in the Gossypium hirsutum (G. hirsutum) genome. We found that PIN1-3 and PIN2 genes originated from the At subgenome were highly expressed in roots. Additionally, evaluation of gene expression patterns indicated that PIN genes are differentially induced by various abiotic stresses. Furthermore, we found that the majority of cotton PIN genes contained auxin (AuxREs) and salicylic acid (SA) responsive elements in their promoter regions were significantly up-regulated by exogenous hormone treatment. Our results provide a comprehensive analysis of the PIN gene family in G. hirsutum, including phylogenetic relationships, chromosomal locations, and gene expression and gene duplication analyses. This study sheds light on the precise roles of PIN genes in cotton root development and in adaption to stress responses.

  2. Functional Reconstitution of a Fungal Natural Product Gene Cluster by Advanced Genome Editing.

    Science.gov (United States)

    Weber, Jakob; Valiante, Vito; Nødvig, Christina S; Mattern, Derek J; Slotkowski, Rebecca A; Mortensen, Uffe H; Brakhage, Axel A

    2017-01-20

    Filamentous fungi produce varieties of natural products even in a strain dependent manner. However, the genetic basis of chemical speciation between strains is still widely unknown. One example is trypacidin, a natural product of the opportunistic human pathogen Aspergillus fumigatus, which is not produced among different isolates. Combining computational analysis with targeted gene editing, we could link a single nucleotide insertion in the polyketide synthase of the trypacidin biosynthetic pathway and reconstitute its production in a nonproducing strain. Thus, we present a CRISPR/Cas9-based tool for advanced molecular genetic studies in filamentous fungi, exploiting selectable markers separated from the edited locus.

  3. Identification and Isolation of Genes Involved in Poly(β-Hydroxybutyrate) Biosynthesis in Azospirillum brasilense and Characterization of a phbC Mutant

    OpenAIRE

    Kadouri, Daniel; Burdman, Saul; Jurkevitch, Edouard; Okon, Yaacov

    2002-01-01

    Like many other prokaryotes, rhizobacteria of the genus Azospirillum produce high levels of poly(β-hydroxybutyrate) (PHB) under suboptimal growth conditions. Utilization of PHB by bacteria under stress has been proposed as a mechanism that favors their compatible establishment in competitive environments, thus showing great potential for the improvement of bacterial inoculants for plants and soils. The three genes that are considered to be essential in the PHB biosynthetic pathway, phbA (β-ke...

  4. Development of a Terpenoid-Production Platform in Streptomyces reveromyceticus SN-593.

    Science.gov (United States)

    Khalid, Ammara; Takagi, Hiroshi; Panthee, Suresh; Muroi, Makoto; Chappell, Joe; Osada, Hiroyuki; Takahashi, Shunji

    2017-12-15

    Terpenoids represent the largest class of natural products, some of which are resources for pharmaceuticals, fragrances, and fuels. Generally, mass production of valuable terpenoid compounds is hampered by their low production levels in organisms and difficulty of chemical synthesis. Therefore, the development of microbial biosynthetic platforms represents an alternative approach. Although microbial terpenoid-production platforms have been established in Escherichia coli and yeast, an optimal platform has not been developed for Streptomyces species, despite the large capacity to produce secondary metabolites, such as polyketide compounds. To explore this potential, we constructed a terpenoid-biosynthetic platform in Streptomyces reveromyceticus SN-593. This strain is unique in that it harbors the mevalonate gene cluster enabling the production of furaquinocin, which can be controlled by the pathway specific regulator Fur22. We simultaneously expressed the mevalonate gene cluster and subsequent terpenoid-biosynthetic genes under the control of Fur22. To achieve improved fur22 gene expression, we screened promoters from S. reveromyceticus SN-593. Our results showed that the promoter associated with rvr2030 gene enabled production of 212 ± 20 mg/L botryococcene to levels comparable to those previously reported for other microbial hosts. Given that the rvr2030 gene encodes for an enzyme involved in the primary metabolism, these results suggest that optimized expression of terpenoid-biosynthetic genes with primary and secondary metabolism might be as important for high yields of terpenoid compounds as is the absolute expression level of a target gene(s).

  5. Biosynthetic origin of the isoprene units in chromenes of Piper aduncum (Piperaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Ana C.; Lopes, Adriana A.; Bolzani, Vanderlan da S.; Furlan, Maysa [UNESP, Araraquara, SP (Brazil). Inst. de Quimica]. E-mail: maysaf@iq.unesp.br; Kato, Massuo J. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica

    2007-07-01

    Metabolic studies involving the incorporation of [1-{sup 13}C]-D-glucose into intact leaves of Piper aduncum (Piperaceae) have indicated that both the mevalonate (MVA) and the pyruvate-triose (MEP) non-mevalonate pathways are implicated in the biosynthesis of isoprene moieties present in methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate (1) and methyl 2,2-dimethyl-8-(3'-methyl- 2'-butenyl)-2H-1-chromene-6-carboxylate (2). The pattern of incorporation of label from [1- {sup 13}C]-D-glucose into these chromenes was determined by quantitative {sup 13}C NMR spectroscopy. The results confirmed that biosynthetic compartment of 1 and 2 could either be the plastid and/ or the cytosol or, possibly, an additional compartment such as the plastid inter-membrane space. (author)

  6. Gene expression in the scleractinian Acropora microphthalma exposed to high solar irradiance reveals elements of photoprotection and coral bleaching.

    Science.gov (United States)

    Starcevic, Antonio; Dunlap, Walter C; Cullum, John; Shick, J Malcolm; Hranueli, Daslav; Long, Paul F

    2010-11-12

    The success of tropical reef-building corals depends on the metabolic co-operation between the animal host and the photosynthetic performance of endosymbiotic algae residing within its cells. To examine the molecular response of the coral Acropora microphthalma to high levels of solar irradiance, a cDNA library was constructed by PCR-based suppression subtractive hybridisation (PCR-SSH) from mRNA obtained by transplantation of a colony from a depth of 12.7 m to near-surface solar irradiance, during which the coral became noticeably paler from loss of endosymbionts in sun-exposed tissues. A novel approach to sequence annotation of the cDNA library gave genetic evidence for a hypothetical biosynthetic pathway branching from the shikimic acid pathway that leads to the formation of 4-deoxygadusol. This metabolite is a potent antioxidant and expected precursor of the UV-protective mycosporine-like amino acids (MAAs), which serve as sunscreens in coral phototrophic symbiosis. Empirical PCR based evidence further upholds the contention that the biosynthesis of these MAA sunscreens is a 'shared metabolic adaptation' between the symbiotic partners. Additionally, gene expression induced by enhanced solar irradiance reveals a cellular mechanism of light-induced coral bleaching that invokes a Ca(2+)-binding synaptotagmin-like regulator of SNARE protein assembly of phagosomal exocytosis, whereby algal partners are lost from the symbiosis. Bioinformatics analyses of DNA sequences obtained by differential gene expression of a coral exposed to high solar irradiance has revealed the identification of putative genes encoding key steps of the MAA biosynthetic pathway. Revealed also by this treatment are genes that implicate exocytosis as a cellular process contributing to a breakdown in the metabolically essential partnership between the coral host and endosymbiotic algae, which manifests as coral bleaching.

  7. Gene expression in the scleractinian Acropora microphthalma exposed to high solar irradiance reveals elements of photoprotection and coral bleaching.

    Directory of Open Access Journals (Sweden)

    Antonio Starcevic

    2010-11-01

    Full Text Available The success of tropical reef-building corals depends on the metabolic co-operation between the animal host and the photosynthetic performance of endosymbiotic algae residing within its cells. To examine the molecular response of the coral Acropora microphthalma to high levels of solar irradiance, a cDNA library was constructed by PCR-based suppression subtractive hybridisation (PCR-SSH from mRNA obtained by transplantation of a colony from a depth of 12.7 m to near-surface solar irradiance, during which the coral became noticeably paler from loss of endosymbionts in sun-exposed tissues.A novel approach to sequence annotation of the cDNA library gave genetic evidence for a hypothetical biosynthetic pathway branching from the shikimic acid pathway that leads to the formation of 4-deoxygadusol. This metabolite is a potent antioxidant and expected precursor of the UV-protective mycosporine-like amino acids (MAAs, which serve as sunscreens in coral phototrophic symbiosis. Empirical PCR based evidence further upholds the contention that the biosynthesis of these MAA sunscreens is a 'shared metabolic adaptation' between the symbiotic partners. Additionally, gene expression induced by enhanced solar irradiance reveals a cellular mechanism of light-induced coral bleaching that invokes a Ca(2+-binding synaptotagmin-like regulator of SNARE protein assembly of phagosomal exocytosis, whereby algal partners are lost from the symbiosis.Bioinformatics analyses of DNA sequences obtained by differential gene expression of a coral exposed to high solar irradiance has revealed the identification of putative genes encoding key steps of the MAA biosynthetic pathway. Revealed also by this treatment are genes that implicate exocytosis as a cellular process contributing to a breakdown in the metabolically essential partnership between the coral host and endosymbiotic algae, which manifests as coral bleaching.

  8. Turnover of radio-iodinated and biosynthetically labelled fibrinogen in rhesus monkeys

    International Nuclear Information System (INIS)

    Moza, A.K.

    1982-01-01

    Successful radio-iodination of monkey fibrinogen using a previously documented method for rabbit fibrinogen is reported. The label was securely bound to fibrinogen without any evidence of polymerisation. Turnover rates and other kinetic parameters of fibrinogen using 125 I-fibrinogen have been compared with those obtained with biosynthetically labelled donor 75 Se-fibrinogen. Both studies yielded identical results. The values for normal monkeys showed a half life of 43.8 +- 1.03 h with 125 I-fibrinogen and 47.15 +- 1.24 with 75 Se-fibrinogen. The turnover rate of endogenous 75 Se-fibrinogen following administration of 75 Se-selenomethionine has also been studied. The half disappearance time value of 100.34 h was much longer than the t1/2 values obtained with either 125 I or 75 Se-fibrinogen. This is believed to be due the staggered input of fibrinogen molecules from the liver. (author)

  9. Leveraging microbial biosynthetic pathways for the generation of 'drop-in' biofuels.

    Science.gov (United States)

    Zargar, Amin; Bailey, Constance B; Haushalter, Robert W; Eiben, Christopher B; Katz, Leonard; Keasling, Jay D

    2017-06-01

    Advances in retooling microorganisms have enabled bioproduction of 'drop-in' biofuels, fuels that are compatible with existing spark-ignition, compression-ignition, and gas-turbine engines. As the majority of petroleum consumption in the United States consists of gasoline (47%), diesel fuel and heating oil (21%), and jet fuel (8%), 'drop-in' biofuels that replace these petrochemical sources are particularly attractive. In this review, we discuss the application of aldehyde decarbonylases to produce gasoline substitutes from fatty acid products, a recently crystallized reductase that could hydrogenate jet fuel precursors from terpene synthases, and the exquisite control of polyketide synthases to produce biofuels with desired physical properties (e.g., lower freezing points). With our increased understanding of biosynthetic logic of metabolic pathways, we discuss the unique advantages of fatty acid, terpene, and polyketide synthases for the production of bio-based gasoline, diesel and jet fuel. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Transcriptome Analysis to Identify the Putative Biosynthesis and Transport Genes Associated with the Medicinal Components of Achyranthes bidentata Bl.

    Directory of Open Access Journals (Sweden)

    Jinting Li

    2016-12-01

    Full Text Available Achyranthes bidentata is a popular perennial medicine herb used for thousands of years in China to treat various diseases. Although this herb has multiple pharmaceutical purposes in China, no transcriptomic information has been reported for this species. In addition, the understanding of several key pathways and enzymes involved in the biosynthesis of oleanolic acid and ecdysterone, two pharmacologically active classes of metabolites and major chemical constituents of A. bidentata root extracts, is limited. The aim of the present study was to characterize the transcriptome profile of the roots and leaves of A. bidentata to uncover the biosynthetic and transport mechanisms of the active components. In this study, we identified 100,987 transcripts, with an average length of 973.64 base pairs. A total of 31,634 (31.33% unigenes were annotated, and 12,762 unigenes were mapped to 303 pathways according to the Kyoto Encyclopedia of Genes and Genomes (KEGG pathway database. Moreover, we identified a total of 260 oleanolic acid and ecdysterone genes encoding biosynthetic enzymes. Furthermore, the key enzymes involved in the oleanolic acid and ecdysterone synthesis pathways were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR, revealing that the roots expressed these enzymes to a greater extent than the leaves. In addition, we identified 85 ATP-binding cassette (ABC transporters, some of which might be involved in the translocation of secondary metabolites.

  11. Identification and molecular characterization of the nicotianamine synthase gene family in bread wheat.

    Science.gov (United States)

    Bonneau, Julien; Baumann, Ute; Beasley, Jesse; Li, Yuan; Johnson, Alexander A T

    2016-12-01

    Nicotianamine (NA) is a non-protein amino acid involved in fundamental aspects of metal uptake, transport and homeostasis in all plants and constitutes the biosynthetic precursor of mugineic acid family phytosiderophores (MAs) in graminaceous plant species. Nicotianamine synthase (NAS) genes, which encode enzymes that synthesize NA from S-adenosyl-L-methionine (SAM), are differentially regulated by iron (Fe) status in most plant species and plant genomes have been found to contain anywhere from 1 to 9 NAS genes. This study describes the identification of 21 NAS genes in the hexaploid bread wheat (Triticum aestivum L.) genome and their phylogenetic classification into two distinct clades. The TaNAS genes are highly expressed during germination, seedling growth and reproductive development. Fourteen of the clade I NAS genes were up-regulated in root tissues under conditions of Fe deficiency. Protein sequence analyses revealed the presence of endocytosis motifs in all of the wheat NAS proteins as well as chloroplast, mitochondrial and secretory transit peptide signals in four proteins. These results greatly expand our knowledge of NAS gene families in graminaceous plant species as well as the genetics underlying Fe nutrition in bread wheat. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  12. Genetic and metabolomic dissection of the ergothioneine and selenoneine biosynthetic pathway in the fission yeast, S. pombe, and construction of an overproduction system.

    Directory of Open Access Journals (Sweden)

    Tomáš Pluskal

    Full Text Available Ergothioneine is a small, sulfur-containing metabolite (229 Da synthesized by various species of bacteria and fungi, which can accumulate to millimolar levels in tissues or cells (e.g. erythrocytes of higher eukaryotes. It is commonly marketed as a dietary supplement due to its proposed protective and antioxidative functions. In this study we report the genes forming the two-step ergothioneine biosynthetic pathway in the fission yeast, Schizosaccharomyces pombe. We identified the first gene, egt1+ (SPBC1604.01, by sequence homology to previously published genes from Neurospora crassa and Mycobacterium smegmatis. We showed, using metabolomic analysis, that the Δegt1 deletion mutant completely lacked ergothioneine and its precursors (trimethyl histidine/hercynine and hercynylcysteine sulfoxide. Since the second step of ergothioneine biosynthesis has not been characterized in eukaryotes, we examined four putative homologs (Nfs1/SPBC21D10.11c, SPAC11D3.10, SPCC777.03c, and SPBC660.12c of the corresponding mycobacterial enzyme EgtE. Among deletion mutants of these genes, only one (ΔSPBC660.12c, designated Δegt2 showed a substantial decrease in ergothioneine, accompanied by accumulation of its immediate precursor, hercynylcysteine sulfoxide. Ergothioneine-deficient strains exhibited no phenotypic defects during vegetative growth or quiescence. To effectively study the role of ergothioneine, we constructed an egt1+ overexpression system by replacing its native promoter with the nmt1+ promoter, which is inducible in the absence of thiamine. We employed three versions of the nmt1 promoter with increasing strength of expression and confirmed corresponding accumulations of ergothioneine. We quantified the intracellular concentration of ergothioneine in S. pombe (0.3, 157.4, 41.6, and up to 1606.3 µM in vegetative, nitrogen-starved, glucose-starved, and egt1+-overexpressing cells, respectively and described its gradual accumulation under long

  13. Transcriptomic landscape of Dendrobium huoshanense and its genes related to polysaccharide biosynthesis

    Directory of Open Access Journals (Sweden)

    Rongchun Han

    2018-03-01

    Full Text Available Dendrobium huoshanense has long been used to treat various diseases in oriental medicine. In order to study its gene expression profile, transcripts involved in the biosynthesis of precursors of polysaccharides, as well as mechanisms underlining morphological differences between wild and cultivated plants, three organs of both wild type and cultivated D. huoshanense were collected and sequenced by Illumina HiSeq4000 platform, yielding 919,409,540 raw reads in FASTQ format. After Trinity de novo assembly and quality control, 241,242 nonredundant contigs with the average length of 967.5 bp were generated. qRT-PCR experiment on the selected transcripts showed the transcriptomic data were reliable. BLASTx was conducted against NR, SwissProt, String, Pfam, and KEGG. Gene ontology annotation revealed more than 40,000 contigs assigned to catalytic activity and metabolic process, suggesting its dynamic physiological activities. By searching KEGG pathway, six genes potentially involved in mannose biosynthetic pathway were retrieved. Gene expression analysis for stems between wild and cultivated D. huoshanense resulted in 956 genes differentially expressed. Simple sequence repeats (SSRs analysis revealed 143 SSRs with the unit size of 4 and 3,437 SSRs the size of 3. The obtained SSRs are the potential molecular markers for discriminating distinct cultivars of D. huoshanense.

  14. Modification of carotenoid levels by abscission agents and expression of carotenoid biosynthetic genes in 'valencia' sweet orange.

    Science.gov (United States)

    Alferez, Fernando; Pozo, Luis V; Rouseff, Russell R; Burns, Jacqueline K

    2013-03-27

    The effect of 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP) and ethephon on peel color, flavedo carotenoid gene expression, and carotenoid accumulation was investigated in mature 'Valencia' orange ( Citrus sinensis L. Osbeck) fruit flavedo at three maturation stages. Abscission agent application altered peel color. CMNP was more effective than ethephon in promoting green-to-red (a) and blue-to-yellow (b) color at the middle and late maturation stages and total carotenoid changes at all maturation stages. Altered flow of carotenoid precursors during maturation due to abscission agents was suggested by changes in phytoene desaturase (Pds) and ζ-carotene desaturase (Zds) gene expression. However, each abscission agent affected downstream expression differentially. Ethephon application increased β-carotene hydroxilase (β-Chx) transcript accumulation 12-fold as maturation advanced from the early to middle and late stages. CMNP markedly increased β- and ε-lycopene cyclase (Lcy) transcript accumulation 45- and 15-fold, respectively, at midmaturation. Patterns of carotenoid accumulation in flavedo were supported in part by gene expression changes. CMNP caused greater accumulation of total flavedo carotenoids at all maturation stages when compared with ethephon or controls. In general, CMNP treatment increased total red carotenoids more than ethephon or the control but decreased total yellow carotenoids at each maturation stage. In control fruit flavedo, total red carotenoids increased and yellow carotenoids decreased as maturation progressed. Trends in total red carotenoids during maturation were consistent with measured a values. Changes in carotenoid accumulation and expression patterns in flavedo suggest that regulation of carotenoid accumulation is under transcriptional, translational, and post-translational control.

  15. Synthesis of ent-BE-43547A1 reveals a potent hypoxia-selective anticancer agent and uncovers the biosynthetic origin of the APD-CLD natural products

    Science.gov (United States)

    Villadsen, Nikolaj L.; Jacobsen, Kristian M.; Keiding, Ulrik B.; Weibel, Esben T.; Christiansen, Bjørn; Vosegaard, Thomas; Bjerring, Morten; Jensen, Frank; Johannsen, Mogens; Tørring, Thomas; Poulsen, Thomas B.

    2017-03-01

    Tumour hypoxia is speculated to be a key driver of therapeutic resistance and metastatic dissemination. Consequently, the discovery of new potent agents that selectively target the hypoxic cell population may reveal new and untapped antitumour mechanisms. Here we demonstrate that the BE-43547 subclass of the APD-CLD (amidopentadienoate-containing cyclolipodepsipeptides) natural products possesses highly hypoxia-selective growth-inhibitory activity against pancreatic cancer cells. To enable this discovery, we have developed the first synthesis of the BE-43547-macrocyclic scaffold in 16 steps (longest linear sequence), which also allowed access to the full panel of relative stereoisomers and ultimately to the assignment of stereochemical configuration. Discrepancies between the spectroscopic signatures of the synthetic compounds with that originally reported for the BE-43547 members stimulated us to re-isolate the natural product from a BE-43547-producing microorganism during which we elucidated the biosynthetic gene clusters for the BE-43547 family as well as for all other known APD-CLDs. Our studies underline the exciting possibilities for the further development of the anticancer activities of these natural products.

  16. Whole genome-wide transcript profiling to identify differentially expressed genes associated with seed field emergence in two soybean low phytate mutants.

    Science.gov (United States)

    Yuan, Fengjie; Yu, Xiaomin; Dong, Dekun; Yang, Qinghua; Fu, Xujun; Zhu, Shenlong; Zhu, Danhua

    2017-01-18

    Seed germination is important to soybean (Glycine max) growth and development, ultimately affecting soybean yield. A lower seed field emergence has been the main hindrance for breeding soybeans low in phytate. Although this reduction could be overcome by additional breeding and selection, the mechanisms of seed germination in different low phytate mutants remain unknown. In this study, we performed a comparative transcript analysis of two low phytate soybean mutants (TW-1 and TW-1-M), which have the same mutation, a 2 bp deletion in GmMIPS1, but show a significant difference in seed field emergence, TW-1-M was higher than that of TW-1 . Numerous genes analyzed by RNA-Seq showed markedly different expression levels between TW-1-M and TW-1 mutants. Approximately 30,000-35,000 read-mapped genes and ~21000-25000 expressed genes were identified for each library. There were ~3900-9200 differentially expressed genes (DEGs) in each contrast library, the number of up-regulated genes was similar with down-regulated genes in the mutant TW-1and TW-1-M. Gene ontology functional categories of DEGs indicated that the ethylene-mediated signaling pathway, the abscisic acid-mediated signaling pathway, response to hormone, ethylene biosynthetic process, ethylene metabolic process, regulation of hormone levels, and oxidation-reduction process, regulation of flavonoid biosynthetic process and regulation of abscisic acid-activated signaling pathway had high correlations with seed germination. In total, 2457 DEGs involved in the above functional categories were identified. Twenty-two genes with 20 biological functions were the most highly up/down- regulated (absolute value Log2FC >5) in the high field emergence mutant TW-1-M and were related to metabolic or signaling pathways. Fifty-seven genes with 36 biological functions had the greatest expression abundance (FRPM >100) in germination-related pathways. Seed germination in the soybean low phytate mutants is a very complex process

  17. Rare variants analysis of cutaneous malignant melanoma genes in Parkinson's disease.

    Science.gov (United States)

    Lubbe, S J; Escott-Price, V; Brice, A; Gasser, T; Pittman, A M; Bras, J; Hardy, J; Heutink, P; Wood, N M; Singleton, A B; Grosset, D G; Carroll, C B; Law, M H; Demenais, F; Iles, M M; Bishop, D T; Newton-Bishop, J; Williams, N M; Morris, H R

    2016-12-01

    A shared genetic susceptibility between cutaneous malignant melanoma (CMM) and Parkinson's disease (PD) has been suggested. We investigated this by assessing the contribution of rare variants in genes involved in CMM to PD risk. We studied rare variation across 29 CMM risk genes using high-quality genotype data in 6875 PD cases and 6065 controls and sought to replicate findings using whole-exome sequencing data from a second independent cohort totaling 1255 PD cases and 473 controls. No statistically significant enrichment of rare variants across all genes, per gene, or for any individual variant was detected in either cohort. There were nonsignificant trends toward different carrier frequencies between PD cases and controls, under different inheritance models, in the following CMM risk genes: BAP1, DCC, ERBB4, KIT, MAPK2, MITF, PTEN, and TP53. The very rare TYR p.V275F variant, which is a pathogenic allele for recessive albinism, was more common in PD cases than controls in 3 independent cohorts. Tyrosinase, encoded by TYR, is the rate-limiting enzyme for the production of neuromelanin, and has a role in the production of dopamine. These results suggest a possible role for another gene in the dopamine-biosynthetic pathway in susceptibility to neurodegenerative Parkinsonism, but further studies in larger PD cohorts are needed to accurately determine the role of these genes/variants in disease pathogenesis. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Chapter 7. Cloning and analysis of natural product pathways.

    Science.gov (United States)

    Gust, Bertolt

    2009-01-01

    The identification of gene clusters of natural products has lead to an enormous wealth of information about their biosynthesis and its regulation, and about self-resistance mechanisms. Well-established routine techniques are now available for the cloning and sequencing of gene clusters. The subsequent functional analysis of the complex biosynthetic machinery requires efficient genetic tools for manipulation. Until recently, techniques for the introduction of defined changes into Streptomyces chromosomes were very time-consuming. In particular, manipulation of large DNA fragments has been challenging due to the absence of suitable restriction sites for restriction- and ligation-based techniques. The homologous recombination approach called recombineering (referred to as Red/ET-mediated recombination in this chapter) has greatly facilitated targeted genetic modifications of complex biosynthetic pathways from actinomycetes by eliminating many of the time-consuming and labor-intensive steps. This chapter describes techniques for the cloning and identification of biosynthetic gene clusters, for the generation of gene replacements within such clusters, for the construction of integrative library clones and their expression in heterologous hosts, and for the assembly of entire biosynthetic gene clusters from the inserts of individual library clones. A systematic approach toward insertional mutation of a complete Streptomyces genome is shown by the use of an in vitro transposon mutagenesis procedure.

  19. Vitamin K2 biosynthetic enzyme, UBIAD1 is essential for embryonic development of mice.

    Science.gov (United States)

    Nakagawa, Kimie; Sawada, Natsumi; Hirota, Yoshihisa; Uchino, Yuri; Suhara, Yoshitomo; Hasegawa, Tomoka; Amizuka, Norio; Okamoto, Tadashi; Tsugawa, Naoko; Kamao, Maya; Funahashi, Nobuaki; Okano, Toshio

    2014-01-01

    UbiA prenyltransferase domain containing 1 (UBIAD1) is a novel vitamin K2 biosynthetic enzyme screened and identified from the human genome database. UBIAD1 has recently been shown to catalyse the biosynthesis of Coenzyme Q10 (CoQ10) in zebrafish and human cells. To investigate the function of UBIAD1 in vivo, we attempted to generate mice lacking Ubiad1, a homolog of human UBIAD1, by gene targeting. Ubiad1-deficient (Ubiad1(-/-)) mouse embryos failed to survive beyond embryonic day 7.5, exhibiting small-sized body and gastrulation arrest. Ubiad1(-/-) embryonic stem (ES) cells failed to synthesize vitamin K2 but were able to synthesize CoQ9, similar to wild-type ES cells. Ubiad1(+/-) mice developed normally, exhibiting normal growth and fertility. Vitamin K2 tissue levels and synthesis activity were approximately half of those in the wild-type, whereas CoQ9 tissue levels and synthesis activity were similar to those in the wild-type. Similarly, UBIAD1 expression and vitamin K2 synthesis activity of mouse embryonic fibroblasts prepared from Ubiad1(+/-) E15.5 embryos were approximately half of those in the wild-type, whereas CoQ9 levels and synthesis activity were similar to those in the wild-type. Ubiad1(-/-) mouse embryos failed to be rescued, but their embryonic lifespans were extended to term by oral administration of MK-4 or CoQ10 to pregnant Ubiad1(+/-) mice. These results suggest that UBIAD1 is responsible for vitamin K2 synthesis but may not be responsible for CoQ9 synthesis in mice. We propose that UBIAD1 plays a pivotal role in embryonic development by synthesizing vitamin K2, but may have additional functions beyond the biosynthesis of vitamin K2.

  20. AP2/ERF Transcription Factor, Ii049, Positively Regulates Lignan Biosynthesis in Isatis indigotica through Activating Salicylic Acid Signaling and Lignan/Lignin Pathway Genes

    Directory of Open Access Journals (Sweden)

    Ruifang Ma

    2017-08-01

    Full Text Available Lignans, such as lariciresinol and its derivatives, have been identified as effective antiviral ingredients in Isatis indigotica. Evidence suggests that the APETALA2/ethylene response factor (AP2/ERF family might be related to the biosynthesis of lignans in I. indigotica. However, the special role played by the AP2/ERF family in the metabolism and its underlying putative mechanism still need to be elucidated. One novel AP2/ERF gene, named Ii049, was isolated and characterized from I. indigotica in this study. The quantitative real-time PCR analysis revealed that Ii049 was expressed highest in the root and responded to methyl jasmonate, salicylic acid (SA and abscisic acid treatments to various degrees. Subcellular localization analysis indicated that Ii049 protein was localized in the nucleus. Knocking-down the expression of Ii049 caused a remarkable reduction of lignan/lignin contents and transcript levels of genes involved in the lignan/lignin biosynthetic pathway. Ii049 bound to the coupled element 1, RAV1AAT and CRTAREHVCBF2 motifs of genes IiPAL and IiCCR, the key structural genes in the lignan/lignin pathway. Furthermore, Ii049 was also essential for SA biosynthesis, and SA induced lignan accumulation in I. indigotica. Notably, the transgenic I. indigotica hairy roots overexpressing Ii049 showed high expression levels of lignan/lignin biosynthetic genes and SA content, resulting in significant accumulation of lignan/lignin. The best-engineered line (OVX049-10 produced 425.60 μg·g−1 lariciresinol, an 8.3-fold increase compared with the wild type production. This study revealed the function of Ii049 in regulating lignan/lignin biosynthesis, which had the potential to increase the content of valuable lignan/lignin in economically significant medicinal plants.

  1. Characterization of the product of a nonribosomal peptide synthetase-like (NRPS-like) gene using the doxycycline dependent Tet-on system in Aspergillus terreus.

    Science.gov (United States)

    Sun, Wei-Wen; Guo, Chun-Jun; Wang, Clay C C

    2016-04-01

    Genome sequencing of the fungus Aspergillus terreus uncovered a number of silent core structural biosynthetic genes encoding enzymes presumed to be involved in the production of cryptic secondary metabolites. There are five nonribosomal peptide synthetase (NRPS)-like genes with the predicted A-T-TE domain architecture within the A. terreus genome. Among the five genes, only the product of pgnA remains unknown. The Tet-on system is an inducible, tunable and metabolism-independent expression system originally developed for Aspergillus niger. Here we report the adoption of the Tet-on system as an effective gene activation tool in A. terreus. Application of this system in A. terreus allowed us to uncover the product of the cryptic NRPS-like gene, pgnA. Furthermore expression of pgnA in the heterologous Aspergillus nidulans host suggested that the pgnA gene alone is necessary for phenguignardic acid (1) biosynthesis. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Evidence for land plant cell wall biosynthetic mechanisms in charophyte green algae

    DEFF Research Database (Denmark)

    Mikkelsen, Maria Dalgaard; Harholt, Jesper; Ulvskov, Peter

    2014-01-01

    in CGA is currently unknown, as no genomes are available, so this study sought to give insight into the evolution of the biosynthetic machinery of CGA through an analysis of available transcriptomes. METHODS: Available CGA transcriptomes were mined for cell wall biosynthesis GTs and compared with GTs...... to colonize land. These cell walls provide support and protection, are a source of signalling molecules, and provide developmental cues for cell differentiation and elongation. The cell wall of land plants is a highly complex fibre composite, characterized by cellulose cross-linked by non......-cellulosic polysaccharides, such as xyloglucan, embedded in a matrix of pectic polysaccharides. How the land plant cell wall evolved is currently unknown: early-divergent chlorophyte and prasinophyte algae genomes contain a low number of glycosyl transferases (GTs), while land plants contain hundreds. The number of GTs...

  3. Endogenous peptide profile for elucidating biosynthetic processing of the ghrelin precursor.

    Science.gov (United States)

    Tsuchiya, Takashi; Iwakura, Hiroshi; Minamino, Naoto; Kangawa, Kenji; Sasaki, Kazuki

    2017-09-02

    Ghrelin is an orexigenic peptide primarily produced by gastric endocrine cells. The biosynthetic cleavage site of ghrelin has been well documented, but how its downstream region undergoes proteolytic processing remains poorly explored. Here, we provide the first snapshot of endogenous peptides from the ghrelin precursor by profiling the secretopeptidome of cultured mouse ghrelin-producing cells during exocytosis. Mapping of MS/MS sequenced peptides to the precursor highlighted three atypical monobasic processing sites, including the established C-terminus of ghrelin and the N-terminal cleavage site for obestatin, a putative 23-amino-acid C-terminally amidated peptide. However, we found that mouse obestatin does not occur in the form originally reported, but that a different amidation site is used to generate a shorter peptide. These data can be extended to study and characterize the precursor-derived peptides located downstream of ghrelin in different biological contexts. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The Aspergillus flavus Homeobox Gene, hbx1, Is Required for Development and Aflatoxin Production

    Directory of Open Access Journals (Sweden)

    Jeffrey W. Cary

    2017-10-01

    Full Text Available Homeobox proteins, a class of well conserved transcription factors, regulate the expression of targeted genes, especially those involved in development. In filamentous fungi, homeobox genes are required for normal conidiogenesis and fruiting body formation. In the present study, we identified eight homeobox (hbx genes in the aflatoxin-producing ascomycete, Aspergillus flavus, and determined their respective role in growth, conidiation and sclerotial production. Disruption of seven of the eight genes had little to no effect on fungal growth and development. However, disruption of the homeobox gene AFLA_069100, designated as hbx1, in two morphologically different A. flavus strains, CA14 and AF70, resulted in complete loss of production of conidia and sclerotia as well as aflatoxins B1 and B2, cyclopiazonic acid and aflatrem. Microscopic examination showed that the Δhbx1 mutants did not produce conidiophores. The inability of Δhbx1 mutants to produce conidia was related to downregulation of brlA (bristle and abaA (abacus, regulatory genes for conidiophore development. These mutants also had significant downregulation of the aflatoxin pathway biosynthetic genes aflC, aflD, aflM and the cluster-specific regulatory gene, aflR. Our results demonstrate that hbx1 not only plays a significant role in controlling A. flavus development but is also critical for the production of secondary metabolites, such as aflatoxins.

  5. tRNA-dependent cysteine biosynthetic pathway represents a strategy to increase cysteine contents by preventing it from thermal degradation: thermal adaptation of methanogenic archaea ancestor.

    Science.gov (United States)

    Qu, Ge; Wang, Wei; Chen, Ling-Ling; Qian, Shao-Song; Zhang, Hong-Yu

    2009-10-01

    Although cysteine (Cys) is beneficial to stabilize protein structures, it is not prevalent in thermophiles. For instance, the Cys contents in most thermophilic archaea are only around 0.7%. However, methanogenic archaea, no matter thermophilic or not, contain relatively abundant Cys, which remains elusive for a long time. Recently, Klipcan et al. correlated this intriguing property of methanogenic archaea with their unique tRNA-dependent Cys biosynthetic pathway. But, the deep reasons underlying the correlation are ambiguous. Considering the facts that free Cys is thermally labile and the tRNA-dependent Cys biosynthesis avoids the use of free Cys, we speculate that the unique Cys biosynthetic pathway represents a strategy to increase Cys contents by preventing it from thermal degradation, which may be relevant to the thermal adaptation of methanogenic archaea ancestor.

  6. Production of 2-deoxyribose 5-phosphate from fructose to demonstrate a potential of artificial bio-synthetic pathway using thermophilic enzymes.

    Science.gov (United States)

    Honda, Kohsuke; Maya, Shohei; Omasa, Takeshi; Hirota, Ryuichi; Kuroda, Akio; Ohtake, Hisao

    2010-08-02

    Six thermophilic enzymes from Thermus thermophilus were used to construct an 'artificial bio-synthetic pathway' for the production of 2-deoxyribose 5-phosphate from fructose. By a simple operation using six recombinant Escherichia coli strains producing the thermophilic enzymes, respectively, fructose was converted to 2-deoxyribose 5-phosphate with a molar yield of 55%. Copyright 2010 Elsevier B.V. All rights reserved.

  7. A Biotin Biosynthesis Gene Restricted to Helicobacter

    Science.gov (United States)

    Bi, Hongkai; Zhu, Lei; Jia, Jia; Cronan, John E.

    2016-01-01

    In most bacteria the last step in synthesis of the pimelate moiety of biotin is cleavage of the ester bond of pimeloyl-acyl carrier protein (ACP) methyl ester. The paradigm cleavage enzyme is Escherichia coli BioH which together with the BioC methyltransferase allows synthesis of the pimelate moiety by a modified fatty acid biosynthetic pathway. Analyses of the extant bacterial genomes showed that bioH is absent from many bioC-containing bacteria and is replaced by other genes. Helicobacter pylori lacks a gene encoding a homologue of the known pimeloyl-ACP methyl ester cleavage enzymes suggesting that it encodes a novel enzyme that cleaves this intermediate. We isolated the H. pylori gene encoding this enzyme, bioV, by complementation of an E. coli bioH deletion strain. Purified BioV cleaved the physiological substrate, pimeloyl-ACP methyl ester to pimeloyl-ACP by use of a catalytic triad, each member of which was essential for activity. The role of BioV in biotin biosynthesis was demonstrated using a reconstituted in vitro desthiobiotin synthesis system. BioV homologues seem the sole pimeloyl-ACP methyl ester esterase present in the Helicobacter species and their occurrence only in H. pylori and close relatives provide a target for development of drugs to specifically treat Helicobacter infections. PMID:26868423

  8. RNA-seq analysis of overexpressing ovine AANAT gene of melatonin biosynthesis in switchgrass

    Directory of Open Access Journals (Sweden)

    Shan Yuan

    2016-08-01

    Full Text Available Melatonin serves important functions in the promotion of growth and anti-stress regulation by efficient radical scavenging and regulation of antioxidant enzyme activity in various plants. To investigate its regulatory roles and metabolism pathways, the transcriptomic profile of overexpressing the ovine arylalkylamine N-acetyltransferase (oAANAT gene, encoding the penultimate enzyme in melatonin biosynthesis, was compared with empty vector (EV control using RNA-seq in switchgrass, a model plant of cellulosic ethanol conversion. The 85.22 million high quality reads that were assembled into 135,684 unigenes were generated by Illumina sequencing for transgenic oAANAT switchgrass with an average sequence length of 716 bp. A total of 946 differential expression genes (DEGs in transgenic line comparing to control switchgrass, including 737 up-regulated and 209 down-regulated genes, were mainly enriched with two main functional patterns of melatonin identifying by gene ontology analysis: the growth regulator and stress tolerance. Furthermore, KEGG maps indicated that the biosynthetic pathways of secondary metabolite (phenylpropanoids, flavonoids, steroids, stilbenoid, diarylheptanoid and gingerol and signaling pathways (MAPK signaling pathway, estrogen signaling pathway were involved in melatonin metabolism. This study substantially expands the transcriptome information for switchgrass and provides valuable clues for identifying candidate genes involved in melatonin biosynthesis and elucidating the mechanism of melatonin metabolism.

  9. Biorhizome: A Biosynthetic Platform for Colchicine Biomanufacturing

    Directory of Open Access Journals (Sweden)

    Ganapathy Sivakumar

    2017-06-01

    Full Text Available Colchicine is one of the oldest plant-based medicines used to treat gout and one of the most important alkaloid-based antimitotic drugs with anticancer potential, which is commercially extracted from Gloriosa superba. Clinical trials suggest that colchicine medication could prevent atrial fibrillation recurrence after cardiac surgery. In addition, therapeutic colchicine is undergoing clinical trials to treat non-diabetic metabolic syndrome and diabetic nephropathy. However, the industrial-scale biomanufacturing of colchicine have not yet been established. Clearly, further studies on detailed biorhizome-specific transcriptome analysis, gene expression, and candidate gene validation are required before uncover the mechanism of colchicine biosynthesis and biorhizome-based colchicine biomanufacturing. Annotation of 32312 assembled multiple-tissues transcripts of G. superba represented 15088 unigenes in known plant specific gene ontology. This could help understanding colchicine biosynthesis in G. superba. This review highlights the biorhizomes, rhizome specific genes or gene what expressed with high level in rhizomes, and deep fluid dynamics in a bioreactor specifically for the biomanufacture of colchicine.

  10. Meta-analysis of Arabidopsis KANADI1 direct target genes identifies basic growth-promoting module acting upstream of hormonal signaling pathways

    DEFF Research Database (Denmark)

    Xie, Yakun; Straub, Daniel; Eguen, Teinai Ebimienere

    2015-01-01

    An intricate network of antagonistically acting transcription factors mediates formation of a flat leaf lamina of Arabidopsis thaliana plants. In this context, members of the class III homeodomain leucine zipper (HD-ZIPIII) transcription factor family specify the adaxial domain (future upper side......) of the leaf, while antagonistically acting KANADI transcription factors determine the abaxial domain (future lower side). Here we used an mRNA-seq approach to identify genes regulated by KANADI1 (KAN1) and subsequently performed a meta-analysis approach combining our datasets with published genome......-wide datasets. Our analysis revealed that KAN1 acts upstream of several genes encoding auxin biosynthetic enzymes. When exposed to shade, we find three YUCCA genes, YUC2, YUC5 and YUC8 to be transcriptionally upregulated, which correlates with an increase in the levels of free auxin. When ectopically expressed...

  11. Wound-induced expression of DEFECTIVE IN ANTHER DEHISCENCE1 and DAD1-like lipase genes is mediated by both CORONATINE INSENSITIVE1-dependent and independent pathways in Arabidopsis thaliana.

    Science.gov (United States)

    Ruduś, Izabela; Terai, Haruka; Shimizu, Takafumi; Kojima, Hisae; Hattori, Kazuki; Nishimori, Yuka; Tsukagoshi, Hironaka; Kamiya, Yuji; Seo, Mitsunori; Nakamura, Kenzo; Kępczyński, Jan; Ishiguro, Sumie

    2014-06-01

    Endogenous JA production is not necessary for wound-induced expression of JA-biosynthetic lipase genes such as DAD1 in Arabidopsis. However, the JA-Ile receptor COI1 is often required for their JA-independent induction. Wounding is a serious event in plants that may result from insect feeding and increase the risk of pathogen infection. Wounded plants produce high amounts of jasmonic acid (JA), which triggers the expression of insect and pathogen resistance genes. We focused on the transcriptional regulation of DEFECTIVE IN ANTHER DEHISCENCE1 and six of its homologs including DONGLE (DGL) in Arabidopsis, which encode lipases involved in JA biosynthesis. Plants constitutively expressing DAD1 accumulated a higher amount of JA than control plants after wounding, indicating that the expression of these lipase genes contributes to determining JA levels. We found that the expression of DAD1, DGL, and other DAD1-LIKE LIPASE (DALL) genes is induced upon wounding. Some DALLs were also expressed in unwounded leaves. Further experiments using JA-biosynthetic and JA-response mutants revealed that the wound induction of these genes is regulated by several distinct pathways. DAD1 and most of its homologs other than DALL4 were fully induced without relying on endogenous JA-Ile production and were only partly affected by JA deficiency, indicating that positive feedback by JA is not necessary for induction of these genes. However, DAD1 and DGL required CORONATINE INSENSITIVE1 (COI1) for their expression, suggesting that a molecule other than JA might act as a regulator of COI1. Wound induction of DALL1, DALL2, and DALL3 did not require COI1. This differential regulation of DAD1 and its homologs might explain their functions at different time points after wounding.

  12. Sequence analysis of porothramycin biosynthetic gene cluster

    Czech Academy of Sciences Publication Activity Database

    Najmanová, Lucie; Ulanová, Dana; Jelínková, Markéta; Kameník, Zdeněk; Kettnerová, Eliška; Koběrská, Markéta; Gažák, Radek; Radojevič, Bojana; Janata, Jiří

    2014-01-01

    Roč. 59, č. 6 (2014), s. 543-552 ISSN 0015-5632 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk(CZ) EE2.3.20.0055; GA MŠk(CZ) EE2.3.30.0003 Institutional support: RVO:61388971 Keywords : BIOLOGICAL-ACTIVITY * ANTHRAMYCIN * SPECIFICITY Subject RIV: EE - Microbiology, Virology Impact factor: 1.000, year: 2014

  13. Didemnin Biosynthetic Gene Cluster In Tistrella Mobilis

    KAUST Repository

    Qian, Pei-Yuan; Xu, Ying Sharon; Lai, Pok-Yui

    2014-01-01

    A novel Tistrella mobilis strain having Accession Deposit Number NRRL B-50531 is provided. A method of producing a didemnin precursor, didemnin or didemnin derivative by using the Tistrella mobilis strain, and the therapeutic composition comprising

  14. Minimum Information about a Biosynthetic Gene cluster

    Czech Academy of Sciences Publication Activity Database

    Medema, M.H.; Petříček, Miroslav

    2015-01-01

    Roč. 11, č. 9 (2015), s. 625-631 ISSN 1552-4450 Institutional support: RVO:61388971 Keywords : NATURAL-PRODUCTS * DATABASE * DISCOVERY Subject RIV: CE - Biochemistry Impact factor: 12.709, year: 2015

  15. Didemnin Biosynthetic Gene Cluster In Tistrella Mobilis

    KAUST Repository

    Qian, Pei-Yuan

    2014-10-02

    A novel Tistrella mobilis strain having Accession Deposit Number NRRL B-50531 is provided. A method of producing a didemnin precursor, didemnin or didemnin derivative by using the Tistrella mobilis strain, and the therapeutic composition comprising at least one didemnin or didemnin derivative produced from the strain or modified strain thereof are also provided.

  16. Prospecting for the incidence of genes involved in ochratoxin and fumonisin biosynthesis in Brazilian strains of Aspergillus niger and Aspergillus welwitschiae.

    Science.gov (United States)

    Massi, Fernanda Pelisson; Sartori, Daniele; de Souza Ferranti, Larissa; Iamanaka, Beatriz Thie; Taniwaki, Marta Hiromi; Vieira, Maria Lucia Carneiro; Fungaro, Maria Helena Pelegrinelli

    2016-03-16

    isolates did not contain these genes. The α-oxoamine synthase gene was detected in 100% and 36% of the A. niger and A. welwitschiae isolates, respectively. The loss of ochratoxin A production in A. niger and A. welwitschiae is highly associated with gene deletions within the ochratoxin biosynthetic gene cluster. The loss of fumonisin production in A. welwitschiae is associated with gene deletions within the fumonisin biosynthetic gene cluster, but this is not the case with A. niger. Published by Elsevier B.V.

  17. Exopolysaccharide (EPS synthesis by Oenococcus oeni: from genes to phenotypes.

    Directory of Open Access Journals (Sweden)

    Maria Dimopoulou

    Full Text Available Oenococcus oeni is the bacterial species which drives malolactic fermentation in wine. The analysis of 50 genomic sequences of O. oeni (14 already available and 36 newly sequenced ones provided an inventory of the genes potentially involved in exopolysaccharide (EPS biosynthesis. The loci identified are: two gene clusters named eps1 and eps2, three isolated glycoside-hydrolase genes named dsrO, dsrV and levO, and three isolated glycosyltransferase genes named gtf, it3, it4. The isolated genes were present or absent depending on the strain and the eps gene clusters composition diverged from one strain to another. The soluble and capsular EPS production capacity of several strains was examined after growth in different culture media and the EPS structure was determined. Genotype to phenotype correlations showed that several EPS biosynthetic pathways were active and complementary in O. oeni. Can be distinguished: (i a Wzy-dependent synthetic pathway, allowing the production of heteropolysaccharides made of glucose, galactose and rhamnose, mainly in a capsular form, (ii a glucan synthase pathway (Gtf, involved in β-glucan synthesis in a free and a cell-associated form, giving a ropy phenotype to growth media and (iii homopolysaccharide synthesis from sucrose (α-glucan or β-fructan by glycoside-hydrolases of the GH70 and GH68 families. The eps gene distribution on the phylogenetic tree was examined. Fifty out of 50 studied genomes possessed several genes dedicated to EPS metabolism. This suggests that these polymers are important for the adaptation of O. oeni to its specific ecological niche, wine and possibly contribute to the technological performance of malolactic starters.

  18. Proteome Profiling Outperforms Transcriptome Profiling for Coexpression Based Gene Function Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing; Ma, Zihao; Carr, Steven A.; Mertins, Philipp; Zhang, Hui; Zhang, Zhen; Chan, Daniel W.; Ellis, Matthew J. C.; Townsend, R. Reid; Smith, Richard D.; McDermott, Jason E.; Chen, Xian; Paulovich, Amanda G.; Boja, Emily S.; Mesri, Mehdi; Kinsinger, Christopher R.; Rodriguez, Henry; Rodland, Karin D.; Liebler, Daniel C.; Zhang, Bing

    2016-11-11

    Coexpression of mRNAs under multiple conditions is commonly used to infer cofunctionality of their gene products despite well-known limitations of this “guilt-by-association” (GBA) approach. Recent advancements in mass spectrometry-based proteomic technologies have enabled global expression profiling at the protein level; however, whether proteome profiling data can outperform transcriptome profiling data for coexpression based gene function prediction has not been systematically investigated. Here, we address this question by constructing and analyzing mRNA and protein coexpression networks for three cancer types with matched mRNA and protein profiling data from The Cancer Genome Atlas (TCGA) and the Clinical Proteomic Tumor Analysis Consortium (CPTAC). Our analyses revealed a marked difference in wiring between the mRNA and protein coexpression networks. Whereas protein coexpression was driven primarily by functional similarity between coexpressed genes, mRNA coexpression was driven by both cofunction and chromosomal colocalization of the genes. Functionally coherent mRNA modules were more likely to have their edges preserved in corresponding protein networks than functionally incoherent mRNA modules. Proteomic data strengthened the link between gene expression and function for at least 75% of Gene Ontology (GO) biological processes and 90% of KEGG pathways. A web application Gene2Net (http://cptac.gene2net.org) developed based on the three protein coexpression networks revealed novel gene-function relationships, such as linking ERBB2 (HER2) to lipid biosynthetic process in breast cancer, identifying PLG as a new gene involved in complement activation, and identifying AEBP1 as a new epithelial-mesenchymal transition (EMT) marker. Our results demonstrate that proteome profiling outperforms transcriptome profiling for coexpression based gene function prediction. Proteomics should be integrated if not preferred in gene function and human disease studies

  19. Iron-regulated transcription of the pvdA gene in Pseudomonas aeruginosa: effect of Fur and PvdS on promoter activity.

    OpenAIRE

    Leoni, L; Ciervo, A; Orsi, N; Visca, P

    1996-01-01

    The pvdA gene, encoding the enzyme L-ornithine N5-oxygenase, catalyzes a key step of the pyoverdin biosynthetic pathway in Pseudomonas aeruginosa. Expression studies with a promoter probe vector made it possible to identify three tightly iron-regulated promoter regions in the 5.9-kb DNA fragment upstream of pvdA. The promoter governing pvdA expression was located within the 154-bp sequence upstream of the pvdA translation start site. RNA analysis showed that expression of PvdA is iron regulat...

  20. Extending the biosynthetic repertoires of cyanobacteria and chloroplasts.

    Science.gov (United States)

    Nielsen, Agnieszka Zygadlo; Mellor, Silas Busck; Vavitsas, Konstantinos; Wlodarczyk, Artur Jacek; Gnanasekaran, Thiyagarajan; Perestrello Ramos H de Jesus, Maria; King, Brian Christopher; Bakowski, Kamil; Jensen, Poul Erik

    2016-07-01

    Chloroplasts in plants and algae and photosynthetic microorganisms such as cyanobacteria are emerging hosts for sustainable production of valuable biochemicals, using only inorganic nutrients, water, CO2 and light as inputs. In the past decade, many bioengineering efforts have focused on metabolic engineering and synthetic biology in the chloroplast or in cyanobacteria for the production of fuels, chemicals and complex, high-value bioactive molecules. Biosynthesis of all these compounds can be performed in photosynthetic organelles/organisms by heterologous expression of the appropriate pathways, but this requires optimization of carbon flux and reducing power, and a thorough understanding of regulatory pathways. Secretion or storage of the compounds produced can be exploited for the isolation or confinement of the desired compounds. In this review, we explore the use of chloroplasts and cyanobacteria as biosynthetic compartments and hosts, and we estimate the levels of production to be expected from photosynthetic hosts in light of the fraction of electrons and carbon that can potentially be diverted from photosynthesis. The supply of reducing power, in the form of electrons derived from the photosynthetic light reactions, appears to be non-limiting, but redirection of the fixed carbon via precursor molecules presents a challenge. We also discuss the available synthetic biology tools and the need to expand the molecular toolbox to facilitate cellular reprogramming for increased production yields in both cyanobacteria and chloroplasts. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  1. Identification of the Biosynthetic Gene Clusters for the Lipopeptides Fusaristatin A and W493 B in Fusarium graminearum and F. pseudograminearum

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Sondergaard, Teis Esben; Covarelli, Lorenzo

    2014-01-01

    The closely related species Fusarium graminearum and Fusarium pseudograminearum differ in that each contains a gene cluster with a polyketide synthase (PKS) and a nonribosomal peptide synthetase (NRPS) that is not present in the other species. To identify their products, we deleted PKS6 and NRPS7...... Fusarium species. On the basis of genes in the putative gene clusters we propose a model for biosynthesis where the polyketide product is shuttled to the NPRS via a CoA ligase and a thioesterase in F. pseudograminearum. In F. graminearum the polyketide is proposed to be directly assimilated by the NRPS....

  2. Overexpression of a novel MADS-box gene SlFYFL delays senescence, fruit ripening and abscission in tomato

    Science.gov (United States)

    Xie, Qiaoli; Hu, Zongli; Zhu, Zhiguo; Dong, Tingting; Zhao, Zhiping; Cui, Baolu; Chen, Guoping

    2014-03-01

    MADS-domain proteins are important transcription factors involved in many biological processes of plants. In our study, a tomato MADS-box gene, SlFYFL, was isolated. SlFYFL is expressed in all tissues of tomato and significantly higher in mature leave, fruit of different stages, AZ (abscission zone) and sepal. Delayed leaf senescence and fruit ripening, increased storability and longer sepals were observed in 35S:FYFL tomato. The accumulation of carotenoid was reduced, and ethylene content, ethylene biosynthetic and responsive genes were down-regulated in 35S:FYFL fruits. Abscission zone (AZ) did not form normally and abscission zone development related genes were declined in AZs of 35S:FYFL plants. Yeast two-hybrid assay revealed that SlFYFL protein could interact with SlMADS-RIN, SlMADS1 and SlJOINTLESS, respectively. These results suggest that overexpression of SlFYFL regulate fruit ripening and development of AZ via interactions with the ripening and abscission zone-related MADS box proteins.

  3. Expression of NCED gene in colored cotton genotypes subjected to water stress

    Directory of Open Access Journals (Sweden)

    Alexandre M. S. de Souza

    Full Text Available ABSTRACT Considering that the NCED gene acts on the biosynthetic cascade of ABA, a hormone involved in the functioning of stomata and consequently in the regulation of transpiration, the aim of this research was to analyze the expression of this gene in colored cotton genotypes subjected to water stress at the beginning of plant growth. Four colored cotton genotypes were used, subjected to two managements, with and without water stress, beginning the treatments when the blade of the first true leaves reached an area that allowed the evaluation of gas exchange. For the studies of the expression of the NCED gene, via RT-qPCR, leaves were collected on three distinct dates: at 4 and 6 days of water stress, and after the plants regained their turgor. The differential expression of NCED was found in all genotypes, with higher levels of expression related to six days of water stress. When the stomatal conductance was around 25%, there was overexpression in the genotype CNPA 2009.13, followed by CNPA 2009.6, BRS SAFIRA and CNPA 2009.11, confirming the data obtained in the semi-quantitative RT-PCR. The NCED gene is involved in the response to water stress in the vegetative phase of colored cotton.

  4. Expression of lycopene biosynthesis genes fused in line with Shine-Dalgarno sequences improves the stress-tolerance of Lactococcus lactis.

    Science.gov (United States)

    Dong, Xiangrong; Wang, Yanping; Yang, Fengyuan; Zhao, Shanshan; Tian, Bing; Li, Tao

    2017-01-01

    Lycopene biosynthetic genes from Deinococcus radiodurans were co-expressed in Lactococcus lactis to produce lycopene and improve its tolerance to stress. Lycopene-related genes from D. radiodurans, DR1395 (crtE), DR0862 (crtB), and DR0861 (crtI), were fused in line with S hine-Dalgarno (SD) sequences and co-expressed in L. lactis. The recombinant strain produced 0.36 mg lycopene g -1  dry cell wt after 48 h fermentation. The survival rate to UV irradiation of the recombinant strain was higher than that of the non-transformed strain. The L. lactis with co-expressed genes responsible for lycopene biosynthesis from D. radiodurans produced lycopene and exhibited increased resistance to UV stress, suggesting that the recombinant strain has important application potential in food industry.

  5. Biosynthetic incorporation of [75Se]selenomethionine: a new method for labelling lymphocyte membrane antigens

    International Nuclear Information System (INIS)

    Dosseto, M.; Rohner, C.; Pierres, M.; Goridis, C.

    1981-01-01

    A novel approach for radiolabelling lymphocyte membrane antigens is described. This technique is based on the use of the γ-emitting amino acid analogue [ 75 Se]selenomethionine. Human HLA-A, B, C and DR heavy and light chains and mouse Ia antigens were efficiently labelled by this technique and were precipitated with monoclonal antibodies. Approximately the same radioactivity was incorporated into the HLA-A, B, C chains whether [ 75 Se]selenomethionine, [ 35 S]methionine or [ 3 H]leucine were used as precursors. Easily detectable as a γ-emitter, [ 75 Se]selenomethionine thus constitutes a useful biosynthetic label of lymphocyte surface antigens. The same method was used to label immunoglobulins produced by hybridomas and to determine the nature of the secreted light chains. (Auth.)

  6. Genome-wide QTL and bulked transcriptomic analysis reveals new candidate genes for the control of tuber carotenoid content in potato (Solanum tuberosum L.).

    Science.gov (United States)

    Campbell, Raymond; Pont, Simon D A; Morris, Jenny A; McKenzie, Gaynor; Sharma, Sanjeev Kumar; Hedley, Pete E; Ramsay, Gavin; Bryan, Glenn J; Taylor, Mark A

    2014-09-01

    Genome-wide QTL analysis of potato tuber carotenoid content was investigated in populations of Solanum tuberosum Group Phureja that segregate for flesh colour, revealing a novel major QTL on chromosome 9. The carotenoid content of edible plant storage organs is a key nutritional and quality trait. Although the structural genes that encode the biosynthetic enzymes are well characterised, much less is known about the factors that determine overall storage organ content. In this study, genome-wide QTL mapping, in concert with an efficient 'genetical genomics' analysis using bulked samples, has been employed to investigate the genetic architecture of potato tuber carotenoid content. Two diploid populations of Solanum tuberosum Group Phureja were genotyped (AFLP, SSR and DArT markers) and analysed for their tuber carotenoid content over two growing seasons. Common to both populations were QTL that explained relatively small proportions of the variation in constituent carotenoids and a major QTL on chromosome 3 explaining up to 71 % of the variation in carotenoid content. In one of the populations (01H15), a second major carotenoid QTL was identified on chromosome 9, explaining up to 20 % of the phenotypic variation. Whereas the major chromosome 3 QTL was likely to be due to an allele of a gene encoding β-carotene hydroxylase, no known carotenoid biosynthetic genes are located in the vicinity of the chromosome 9 QTL. A unique expression profiling strategy using phenotypically distinct bulks comprised individuals with similar carotenoid content provided further support for the QTL mapping to chromosome 9. This study shows the potential of using the potato genome sequence to link genetic maps to data arising from eQTL approaches to enhance the discovery of candidate genes underlying QTLs.

  7. Enhancement of Chlorogenic Acid Production in Hairy Roots of Platycodon grandiflorum by Over-Expression of An Arabidopsis thaliana Transcription Factor AtPAP1

    Directory of Open Access Journals (Sweden)

    Pham Anh Tuan

    2014-08-01

    Full Text Available To improve the production of chlorogenic acid (CGA in hairy roots of Platycodon grandiflorum, we induced over-expression of Arabidopsis thaliana transcription factor production of anthocyanin pigment (AtPAP1 using an Agrobacterium rhizogenes-mediated transformation system. Twelve hairy root lines showing over-expression of AtPAP1 were generated. In order to investigate the regulation of AtPAP1 on the activities of CGA biosynthetic genes, the expression levels of seven P. grandiflorum CGA biosynthetic genes were analyzed in the hairy root line that had the greatest accumulation of AtPAP1 transcript, OxPAP1-1. The introduction of AtPAP1 increased the mRNA levels of all examined CGA biosynthetic genes and resulted in a 900% up-regulation of CGA accumulation in OxPAP1-1 hairy roots relative to controls. This suggests that P. grandiflorum hairy roots that over-express the AtPAP1 gene are a potential alternative source of roots for the production of CGA.

  8. Phylogeny-guided (meta)genome mining approach for the targeted discovery of new microbial natural products.

    Science.gov (United States)

    Kang, Hahk-Soo

    2017-02-01

    Genomics-based methods are now commonplace in natural products research. A phylogeny-guided mining approach provides a means to quickly screen a large number of microbial genomes or metagenomes in search of new biosynthetic gene clusters of interest. In this approach, biosynthetic genes serve as molecular markers, and phylogenetic trees built with known and unknown marker gene sequences are used to quickly prioritize biosynthetic gene clusters for their metabolites characterization. An increase in the use of this approach has been observed for the last couple of years along with the emergence of low cost sequencing technologies. The aim of this review is to discuss the basic concept of a phylogeny-guided mining approach, and also to provide examples in which this approach was successfully applied to discover new natural products from microbial genomes and metagenomes. I believe that the phylogeny-guided mining approach will continue to play an important role in genomics-based natural products research.

  9. McMYB12 Transcription Factors Co-regulate Proanthocyanidin and Anthocyanin Biosynthesis in Malus Crabapple.

    Science.gov (United States)

    Tian, Ji; Zhang, Jie; Han, Zhen-Yun; Song, Ting-Ting; Li, Jin-Yan; Wang, Ya-Ru; Yao, Yun-Cong

    2017-03-03

    The flavonoid compounds, proanthocyanidins (PAs), protect plants from biotic stresses, contribute to the taste of many fruits, and are beneficial to human health in the form of dietary antioxidants. In this study, we functionally characterized two Malus crabapple R2R3-MYB transcription factors, McMYB12a and McMYB12b, which co-regulate PAs and anthocyanin biosynthesis. McMYB12a was shown to be mainly responsible for upregulating the expression of anthocyanin biosynthetic genes by binding to their promoters, but to be only partially responsible for regulating PAs biosynthetic genes. In contrast, McMYB12b showed preferential binding to the promoters of PAs biosynthetic genes. Overexpression of McMYB12a and McMYB12b in tobacco (Nicotiana tabacum) altered the expression of flavonoid biosynthetic genes and promoted the accumulation of PAs and anthocyanins in tobacco petals. Conversely, transient silencing their expression in crabapple plants, using a conserved gene region, resulted in reduced PAs and anthocyanin production a green leaf phenotype. Meanwhile, transient overexpression of the two genes and silenced McMYB12s in apple (Malus domestica) fruit had a similar effect as overexpression in tobacco and silenced in crabapple. This study reveals a new mechanism for the coordinated regulation of PAs and anthocyanin accumulation in crabapple leaves, which depends on an auto-regulatory balance involving McMYB12a and McMYB12b expression.

  10. Dynamic Transcription profiles of Qinguan apple (Malus × domestica leaves in response to Marssonina coronaria inoculation

    Directory of Open Access Journals (Sweden)

    Junke eZhang

    2015-10-01

    Full Text Available Marssonina apple blotch, caused by the fungus Marssonina coronaria, is one of the most destructive apple diseases in China and East Asia. A better understanding of the plant’s response to fungi during pathogenesis is urgently needed to improve plant resistance and to breed resistant cultivars. To address this, the transcriptomes of ‘Qinguan’ (a cultivar with high resistance to M. coronaria apple leaves were sequenced at 12, 24, 48 and 72 hours post-inoculation (hpi with Marssonina coronaria. The comparative results showed that a total of 1956 genes were differentially expressed between the inoculated and control samples at the 4 time points. Gene ontology (GO term enrichment analysis of differentially expressed genes (DEGs revealed changes in cellular component, secondary metabolism including chalcone isomerase activity, phytoalexin biosynthetic process, anthocyanin-containing compound biosynthetic process, lignin biosynthetic process, positive regulation of flavonoid biosynthetic process; and molecular functions or biological processes related to the defense response, biotic stimulus response, wounding response and fungus response. Kyoto Encyclopedia of Genes and Genomes (KEGG pathway analysis showed that DEGs were significantly enriched in flavonoid biosynthesis, vitamin B6 metabolism, phenylpropanoid biosynthesis, and the stilbenoid, diarylheptanoid and gingerol biosynthesis pathways. Furthermore, the importance of changes in cellular components and partial polyphenol compounds when encountering M. coronaria are discussed.

  11. [Correlation of gene expression related to amount of ginseng saponin in 15 tissues and 6 kinds of ginseng saponin biosynthesis].

    Science.gov (United States)

    Wang, Kang-yu; Zhang, Mei-ping; Li, Chuang; Jiang, Shi-cui; Yin, Rui; Sun, Chun-yu; Wang, Yi

    2015-08-01

    Fifteen tissues of 4-year-old fruit repining stage Jilin ginseng were chosen as materials, six kinds of monomer saponins (ginsenosides Rg1, Re, Rb1, Rc, Rb2 and Rd) content in 15 tissues was measured by HPLC and vanillin-sulfuric acid method. The relative expression of FPS, SQS, SQE, OSC, β-AS and P450 genes in 15 tissues was analyzed by real-time PCR. The correlations between ginseng saponin content in 15 tissues of Jilin ginseng and biosynthetic pathway -related genes were obtained. The results showed that was a synergistic increase and decrease trend of positive linear correlation among six kinds of monomer saponin content, and there was a significantly (P saponin content and total saponins content. Monomer saponin content and 6 kinds of enzyme gene correlation were different. Biosynthesis of ginseng total saponins and monomer saponin were regulated by six kinds of participation ginsenoside biosynthesis enzyme genes, the expression of these six kinds of genes in different tissues of ginseng showed collaborative increase and decrease trend, and regulated biosynthesis of ginseng ginsenoside by group coordinative manner.

  12. Improved fructan accumulation in perennial ryegrass transformed with the onion fructosyltransferase genes 1-SST and 6G-FFT

    DEFF Research Database (Denmark)

    Gadegaard, Gitte; Didion, Thomas; Foiling, Marianne

    2008-01-01

    Carbohydrate limitation has been identified as a main cause of inefficient nitrogen use in ruminant animals, which feed mainly on fresh forage, hay and silage. This inefficiency results in suboptimal meat and milk productivity. One important molecular breeding strategy is to improve the nutritional...... value of ryegrass (Lolium perenne) by increasing the fructan content through expression of heterologous fructan biosynthetic genes. We developed perennial ryegrass Lines expressing sucrose:sucrose 1-fructosyltransferase and fructan:fructan 6G-fructosyltransferase genes from onion (Allium cepa) which...... exhibited up to a 3-fold increased fructan content. Further, the high fructan content was stable during the growth period, whereas the fructan content in an elite variety, marketed as a high sugar variety, dropped rapidly after reaching its maximum and subsequently remained low. (c) 2007 Elsevier GmbH. ALL...

  13. Medically important carotenoids from Momordica charantia and their gene expressions in different organs.

    Science.gov (United States)

    Cuong, Do Manh; Arasu, Mariadhas Valan; Jeon, Jin; Park, Yun Ji; Kwon, Soon-Jae; Al-Dhabi, Naif Abdullah; Park, Sang Un

    2017-12-01

    Carotenoids, found in the fruit and different organs of bitter melon ( Momordica charantia ), have attracted great attention for their potential health benefits in treating several major chronic diseases. Therefore, study related to the identification and quantification of the medically important carotenoid metabolites is highly important for the treatment of various disorderes. The present study involved in the identification and quantification of the various carotenoids present in the different organs of M. charantia and the identification of the genes responsible for the accumulation of the carotenoids with respect to the transcriptome levels were investigated. In this study, using the transcriptome database of bitter melon, a partial-length cDNA clone encoding geranylgeranyl pyrophosphate synthase ( McGGPPS2 ), and several full-length cDNA clones encoding geranylgeranyl pyrophosphate synthase ( McGGPPS1 ), zeta-carotene desaturase ( McZDS ), lycopene beta-cyclase ( McLCYB ), lycopene epsilon cyclases ( McLCYE1 and McLCYE2 ), beta-carotene hydroxylase ( McCHXB ), and zeaxanthin epoxidase ( McZEP ) were identified in bitter melon . The expression levels of the mRNAs encoding these eight putative biosynthetic enzymes, as well as the accumulation of lycopene, α-carotene, lutein, 13Z-β-carotene, E-β-carotene, 9Z-β-carotene, β-cryptoxanthin, zeaxanthin, antheraxanthin, and violaxanthin were investigated in different organs from M. charantia as well as in the four different stages of its fruit maturation. Transcripts were found to be constitutively expressed at high levels in the leaves where carotenoids were also found at the highest levels . Collectively, these results indicate that the putative McGGPPS2, McZDS, McLCYB, McLCYE1, McLCYE2, and McCHXB enzymes might be key factors in controlling carotenoid content in bitter melon . In conclusion, the over expression of the carotenoid biosynthetic genes from M. charantia crops to increase the yield of these

  14. Swainsonine Biosynthesis Genes in Diverse Symbiotic and Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Daniel Cook

    2017-06-01

    Full Text Available Swainsonine—a cytotoxic fungal alkaloid and a potential cancer therapy drug—is produced by the insect pathogen and plant symbiont Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glory symbiont belonging to order Chaetothyriales. Genome sequence analyses revealed that these fungi share orthologous gene clusters, designated “SWN,” which included a multifunctional swnK gene comprising predicted adenylylation and acyltransferase domains with their associated thiolation domains, a β-ketoacyl synthase domain, and two reductase domains. The role of swnK was demonstrated by inactivating it in M. robertsii through homologous gene replacement to give a ∆swnK mutant that produced no detectable swainsonine, then complementing the mutant with the wild-type gene to restore swainsonine biosynthesis. Other SWN cluster genes were predicted to encode two putative hydroxylases and two reductases, as expected to complete biosynthesis of swainsonine from the predicted SwnK product. SWN gene clusters were identified in six out of seven sequenced genomes of Metarhzium species, and in all 15 sequenced genomes of Arthrodermataceae, a family of fungi that cause athlete’s foot and ringworm diseases in humans and other mammals. Representative isolates of all of these species were cultured, and all Metarhizium spp. with SWN clusters, as well as all but one of the Arthrodermataceae, produced swainsonine. These results suggest a new biosynthetic hypothesis for this alkaloid, extending the known taxonomic breadth of swainsonine producers to at least four orders of Ascomycota, and suggest that swainsonine has roles in mutualistic symbioses and diseases of plants and animals.

  15. Horizontally Acquired Biosynthesis Genes Boost Coxiella burnetii's Physiology.

    Science.gov (United States)

    Moses, Abraham S; Millar, Jess A; Bonazzi, Matteo; Beare, Paul A; Raghavan, Rahul

    2017-01-01

    Coxiella burnetii , the etiologic agent of acute Q fever and chronic endocarditis, has a unique biphasic life cycle, which includes a metabolically active intracellular form that occupies a large lysosome-derived acidic vacuole. C. burnetii is the only bacterium known to thrive within such an hostile intracellular niche, and this ability is fundamental to its pathogenicity; however, very little is known about genes that facilitate Coxiella 's intracellular growth. Recent studies indicate that C. burnetii evolved from a tick-associated ancestor and that the metabolic capabilities of C. burnetii are different from that of Coxiella -like bacteria found in ticks. Horizontally acquired genes that allow C. burnetii to infect and grow within mammalian cells likely facilitated the host shift; however, because of its obligate intracellular replication, C. burnetii would have lost most genes that have been rendered redundant due to the availability of metabolites within the host cell. Based on these observations, we reasoned that horizontally derived biosynthetic genes that have been retained in the reduced genome of C. burnetii are ideal candidates to begin to uncover its intracellular metabolic requirements. Our analyses identified a large number of putative foreign-origin genes in C. burnetii , including tRNA Glu 2 that is potentially required for heme biosynthesis, and genes involved in the production of lipopolysaccharide-a virulence factor, and of critical metabolites such as fatty acids and biotin. In comparison to wild-type C. burnetii , a strain that lacks tRNA Glu 2 exhibited reduced growth, indicating its importance to Coxiella 's physiology. Additionally, by using chemical agents that block heme and biotin biosyntheses, we show that these pathways are promising targets for the development of new anti- Coxiella therapies.

  16. Detection and characterization of broad-spectrum antipathogen activity of novel rhizobacterial isolates and suppression of Fusarium crown and root rot disease of tomato.

    Science.gov (United States)

    Zhang, L; Khabbaz, S E; Wang, A; Li, H; Abbasi, P A

    2015-03-01

    To detect and characterize broad-spectrum antipathogen activity of indigenous bacterial isolates obtained from potato soil and soya bean leaves for their potential to be developed as biofungicides to control soilborne diseases such as Fusarium crown and root rot of tomato (FCRR) caused by Fusarium oxysporum f. sp. radicis-lycopersici (Forl). Thirteen bacterial isolates (Bacillus amyloliquefaciens (four isolates), Paenibacillus polymyxa (three isolates), Pseudomonas chlororaphis (two isolates), Pseudomonas fluorescens (two isolates), Bacillus subtilis (one isolate) and Pseudomonas sp. (one isolate)) or their volatiles showed antagonistic activity against most of the 10 plant pathogens in plate assays. Cell-free culture filtrates (CF) of five isolates or 1-butanol extracts of CFs also inhibited the growth of most pathogen mycelia in plate assays. PCR analysis confirmed the presence of most antibiotic biosynthetic genes such as phlD, phzFA, prnD and pltC in most Pseudomonas isolates and bmyB, bacA, ituD, srfAA and fenD in most Bacillus isolates. These bacterial isolates varied in the production of hydrogen cyanide (HCN), siderophores, β-1,3-glucanases, chitinases, proteases, indole-3-acetic acid, salicylic acid, and for nitrogen fixation and phosphate solubilization. Gas chromatography-mass spectrometry analysis identified 10 volatile compounds from 10 isolates and 18 compounds from 1-butanol extracts of CFs of five isolates. Application of irradiated peat formulation of six isolates to tomato roots prior to transplanting in a Forl-infested potting mix and field soil provided protection of tomato plants from FCRR disease and enhanced plant growth under greenhouse conditions. Five of the 13 indigenous bacterial isolates were antagonistic to eight plant pathogens, both in vitro and in vivo. Antagonistic and plant-growth promotion activities of these isolates might be related to the production of several types of antibiotics, lytic enzymes, phytohormones, secondary

  17. A Possible Trifunctional β-Carotene Synthase Gene Identified in the Draft Genome of Aurantiochytrium sp. Strain KH105

    Directory of Open Access Journals (Sweden)

    Hiroaki Iwasaka

    2018-04-01

    Full Text Available Labyrinthulomycetes have been regarded as a promising industrial source of xanthophylls, including astaxanthin and canthaxanthin, polyunsaturated fatty acids such as docosahexaenoic acid and docosapentaenoic acid, ω-3 oils, and terpenic hydrocarbons, such as sterols and squalene. A Thraustochytrid, Aurantiochytrium sp. KH105 produces carotenoids, including astaxanthin, with strong antioxidant activity. To gain genomic insights into this capacity, we decoded its 97-Mbp genome and characterized genes for enzymes involved in carotenoid biosynthesis. Interestingly, all carotenogenic genes, as well as other eukaryotic genes, appeared duplicated, suggesting that this strain is diploid. In addition, among the five genes involved in the pathway from geranylgeranyl pyrophosphate to astaxanthin, geranylgeranyl phytoene synthase (crtB, phytoene desaturase (crtI and lycopene cyclase (crtY were fused into single gene (crtIBY with no internal stop codons. Functionality of the trifunctional enzyme, CrtIBY, to catalyze the reaction from geranylgeranyl diphosphate to β-carotene was confirmed using a yeast assay system and mass spectrometry. Furthermore, analyses of differential gene expression showed characteristic up-regulation of carotenoid biosynthetic genes during stationary and starvation phases under these culture conditions. This suggests genetic engineering events to promote more efficient production of carotenoids. We also showed an occurrence of crtIBY in other Thraustochytrid species.

  18. Phosphorus starvation induces post-transcriptional CHS gene silencing in Petunia corolla.

    Science.gov (United States)

    Hosokawa, Munetaka; Yamauchi, Takayoshi; Takahama, Masayoshi; Goto, Mariko; Mikano, Sachiko; Yamaguchi, Yuki; Tanaka, Yoshiyuki; Ohno, Sho; Koeda, Sota; Doi, Motoaki; Yazawa, Susumu

    2013-05-01

    The corolla of Petunia 'Magic Samba' exhibits unstable anthocyanin expression depending on its phosphorus content. Phosphorus deficiency enhanced post-transcriptional gene silencing of chalcone synthase - A in the corolla. Petunia (Petunia hybrida) 'Magic Samba' has unstable red-white bicolored corollas that respond to nutrient deficiency. We grew this cultivar hydroponically using solutions that lacked one or several nutrients to identify the specific nutrient related to anthocyanin expression in corolla. The white area of the corolla widened under phosphorus (P)-deficient conditions. When the P content of the corolla grown under P-deficient conditions dropped to 40 corollas until the plants died. Other elemental deficiencies had no clear effects on anthocyanin suppression in the corolla. After phosphate was resupplied to the P-deficient plants, anthocyanin was restored in the corollas. The expression of chalcone synthase-A (CHS-A) was suppressed in the white area that widened under P-suppressed conditions, whereas the expression of several other genes related to anthocyanin biosynthesis was enhanced more in the white area than in the red area. Reddish leaves and sepals developed under the P-deficient condition, which is a typical P-deficiency symptom. Two genes related to anthocyanin biosynthesis were enhanced in the reddish organs. Small interfering RNA analysis of CHS-A showed that the suppression resulted from post-transcriptional gene silencing (PTGS). Thus, it was hypothesized that the enhancement of anthocyanin biosynthetic gene expression due to P-deficiency triggered PTGS of CHS-A, which resulted in white corolla development.

  19. Genome-wide screen in Saccharomyces cerevisiae identifies vacuolar protein sorting, autophagy, biosynthetic, and tRNA methylation genes involved in life span regulation.

    Science.gov (United States)

    Fabrizio, Paola; Hoon, Shawn; Shamalnasab, Mehrnaz; Galbani, Abdulaye; Wei, Min; Giaever, Guri; Nislow, Corey; Longo, Valter D

    2010-07-15

    The study of the chronological life span of Saccharomyces cerevisiae, which measures the survival of populations of non-dividing yeast, has resulted in the identification of homologous genes and pathways that promote aging in organisms ranging from yeast to mammals. Using a competitive genome-wide approach, we performed a screen of a complete set of approximately 4,800 viable deletion mutants to identify genes that either increase or decrease chronological life span. Half of the putative short-/long-lived mutants retested from the primary screen were confirmed, demonstrating the utility of our approach. Deletion of genes involved in vacuolar protein sorting, autophagy, and mitochondrial function shortened life span, confirming that respiration and degradation processes are essential for long-term survival. Among the genes whose deletion significantly extended life span are ACB1, CKA2, and TRM9, implicated in fatty acid transport and biosynthesis, cell signaling, and tRNA methylation, respectively. Deletion of these genes conferred heat-shock resistance, supporting the link between life span extension and cellular protection observed in several model organisms. The high degree of conservation of these novel yeast longevity determinants in other species raises the possibility that their role in senescence might be conserved.

  20. Gene expression changes in female zebrafish (Danio rerio) brain in response to acute exposure to methylmercury

    Science.gov (United States)

    Richter, Catherine A.; Garcia-Reyero, Natàlia; Martyniuk, Chris; Knoebl, Iris; Pope, Marie; Wright-Osment, Maureen K.; Denslow, Nancy D.; Tillitt, Donald E.

    2011-01-01

    Methylmercury (MeHg) is a potent neurotoxicant and endocrine disruptor that accumulates in aquatic systems. Previous studies have shown suppression of hormone levels in both male and female fish, suggesting effects on gonadotropin regulation in the brain. The gene expression profile in adult female zebrafish whole brain induced by acute (96 h) MeHg exposure was investigated. Fish were exposed by injection to 0 or 0.5(mu or u)g MeHg/g. Gene expression changes in the brain were examined using a 22,000-feature zebrafish microarray. At a significance level of pgenes were up-regulated and 76 genes were down-regulated in response to MeHg exposure. Individual genes exhibiting altered expression in response to MeHg exposure implicate effects on glutathione metabolism in the mechanism of MeHg neurotoxicity. Gene ontology (GO) terms significantly enriched among altered genes included protein folding, cell redox homeostasis, and steroid biosynthetic process. The most affected biological functions were related to nervous system development and function, as well as lipid metabolism and molecular transport. These results support the involvement of oxidative stress and effects on protein structure in the mechanism of action of MeHg in the female brain. Future studies will compare the gene expression profile induced in response to MeHg with that induced by other toxicants and will investigate responsive genes as potential biomarkers of MeHg exposure.

  1. Differential accumulation of β-carotene and tissue specific expression of phytoene synthase (MaPsy) gene in banana (Musa sp) cultivars.

    Science.gov (United States)

    Dhandapani, R; Singh, V P; Arora, A; Bhattacharya, R C; Rajendran, Ambika

    2017-12-01

    An experiment was conducted with twelve major Indian banana cultivars to investigate the molecular relationship between the differential accumulation of β-carotene in peel and pulp of the banana fruit and carotenoid biosynthetic pathway genes. The high performance liquid chromatography showed that all banana cultivars accumulated two-three fold more β-carotene in non-edible portion of the banana fruit. However, Nendran , a famous orange fleshed cultivar of South India, had high β-carotene content (1362 µg/100 g) in edible pulp. The gene encoding Musa accuminata phytoene synthase ( MaPsy ) was successfully amplified using a pair of degenerate primers designed from Oncidium orchid. The deduced amino acid sequences shared a high level of identity to phytoene synthase gene from other plants. Gene expression analysis confirmed the presence of two isoforms ( MaPsy1 and MaPsy2 ) of MaPsy gene in banana fruits. Presence of two isoforms of MaPsy gene in peel and one in pulp confirmed the differential accumulation of β-carotene in banana fruits. However, Nendran accumulated more β-carotene in edible pulp due to presence of both the isoforms of MaPsy gene. Thus, carotenoid accumulation is a tissue specific process strongly dependent on differential expression pattern of two isoforms of MaPsy gene in banana.

  2. Construction of an engineering strain which knocked out the gene of thioesterase for Streptomyces parvus HCCB10043 and the reach of metabolites

    Directory of Open Access Journals (Sweden)

    YIN Fang

    2013-08-01

    Full Text Available The major metabolites of Streptomyces parvus HCCB10043 is lipopeptide compounds A21978C,its genome sequence includes the non ribosomal peptide synthetase(NRPS,polyketide synthases(PKS and hybrid NRPS-PKS multi-enzyme system gene clusters,they do have a their common feature in the metabolite biosynthetic cluster,which is called TE domain as well.Thioesterase can synthesized the synthesis of compounds of the chain termination,and with functions to release mature lipopeptide hydrolysis and cyclized peptide chain aliphatic linear.This study,we knockout the TE domain of a gene cluster,which guide the biosynthesis of bipyridine,to obtain engineered bacteria.The fermentation results demonstrates reduced yields for metabolites 2,2′-Bipyridine (2,2′-BP.

  3. Biosynthesis and Total Synthesis of Pyrronazol B: a Secondary Metabolite from Nannocystis pusilla.

    Science.gov (United States)

    Witte, Swjatoslaw N R; Hug, Joachim J; Géraldy, Magalie N E; Müller, Rolf; Kalesse, Markus

    2017-11-13

    The first stereoselective total synthesis of the natural product pyrronazol B, which contains a chlorinated pyrrole-oxazole-pyrone framework, has been achieved. Genome sequencing of the myxobacterial producer strain Nannocystis pusilla Ari7 led to the identification of the putative biosynthetic gene cluster. The proposed biosynthetic pathway was supported by feeding experiments with stable isotopes of three biosynthetic building blocks, namely l-proline, l-serine, and l-methionine. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. [Molecular cloning, expression and characterization of lysine decarboxylase gene of endophytic fungus Shiraia sp. Slf14 from Huperzia serrata].

    Science.gov (United States)

    Peng, Silu; Yang, Huilin; Zhu, Du; Zhang, Zhibin; Yan, Riming; Wang, Ya

    2016-04-14

    Huperzine A (HupA) was approved as a drug for the treatment of Alzheimer's disease. The HupA biosynthetic pathway was started from lysine decarboxylase (LDC), which catalyzes lysine to cadaverine. In this study, we cloned and expressed an LDC gene from a HupA-producing endophytic fungus, and tested LDC activities. An endophytic fungus Shiraia sp. Slf14 from Huperzia serrata was used. LDC gene was obtained by RT-PCR, and cloned into pET-22b(+) and pET-32a(+) vectors to construct recombinant plasmids pET- 22b-LDC and pET-32a-LDC. These two recombinant plasmids were transformed into E. coli BL21, cultured for 8 h at 24 °C, 200 r/min with 1×10–3 mol/L IPTG into medium to express the LDC proteins, respectively. LDC proteins were purified by Ni2+ affinity chromatography. Catalytic activities were measured by Thin Layer Chromatography. At last, the physicochemical properties and structures of these two LDCs were obtained by bioinformatics software. LDC and Trx-LDC were expressed in E. coli BL21 successfully. SDS-PAGE analysis shows that the molecular weight of LDC and Trx-LDC were 24.4 kDa and 42.7 kDa respectively, which are consistent with bioinformatics analysis. In addition, TLC analysis reveals that both LDC and Trx-LDC had catalytic abilities. This work can provide fundamental data for enriching LDC molecular information and reveal the HupA biosynthetic pathway in endophytic fungi.

  5. Genome-wide screen in Saccharomyces cerevisiae identifies vacuolar protein sorting, autophagy, biosynthetic, and tRNA methylation genes involved in life span regulation.

    Directory of Open Access Journals (Sweden)

    Paola Fabrizio

    2010-07-01

    Full Text Available The study of the chronological life span of Saccharomyces cerevisiae, which measures the survival of populations of non-dividing yeast, has resulted in the identification of homologous genes and pathways that promote aging in organisms ranging from yeast to mammals. Using a competitive genome-wide approach, we performed a screen of a complete set of approximately 4,800 viable deletion mutants to identify genes that either increase or decrease chronological life span. Half of the putative short-/long-lived mutants retested from the primary screen were confirmed, demonstrating the utility of our approach. Deletion of genes involved in vacuolar protein sorting, autophagy, and mitochondrial function shortened life span, confirming that respiration and degradation processes are essential for long-term survival. Among the genes whose deletion significantly extended life span are ACB1, CKA2, and TRM9, implicated in fatty acid transport and biosynthesis, cell signaling, and tRNA methylation, respectively. Deletion of these genes conferred heat-shock resistance, supporting the link between life span extension and cellular protection observed in several model organisms. The high degree of conservation of these novel yeast longevity determinants in other species raises the possibility that their role in senescence might be conserved.

  6. Multicenter, Prospective, Longitudinal Study of the Recurrence, Surgical Site Infection, and Quality of Life After Contaminated Ventral Hernia Repair Using Biosynthetic Absorbable Mesh: The COBRA Study

    NARCIS (Netherlands)

    Rosen, M.J.; Bauer, J.J.; Harmaty, M.; Carbonell, A.M.; Cobb, W.S.; Matthews, B.; Goldblatt, M.I.; Selzer, D.J.; Poulose, B.K.; Hansson, B.M.E.; Rosman, C.; Chao, J.J.; Jacobsen, G.R.

    2017-01-01

    OBJECTIVE: The aim of the study was to evaluate biosynthetic absorbable mesh in single-staged contaminated (Centers for Disease Control class II and III) ventral hernia (CVH) repair over 24 months. BACKGROUND: CVH has an increased risk of postoperative infection. CVH repair with synthetic or

  7. Seasonal shifts in accumulation of glycerol biosynthetic gene transcripts in mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae, larvae

    Directory of Open Access Journals (Sweden)

    Jordie D. Fraser

    2017-06-01

    Full Text Available Winter mortality is a major factor regulating population size of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae. Glycerol is the major cryoprotectant in this freeze intolerant insect. We report findings from a gene expression study on an overwintering mountain pine beetle population over the course of 35 weeks. mRNA transcript levels suggest glycerol production in the mountain pine beetle occurs through glycogenolytic, gluconeogenic and potentially glyceroneogenic pathways, but not from metabolism of lipids. A two-week lag period between fall glycogen phosphorylase transcript and phosphoenolpyruvate carboxykinase transcript up-regulation suggests that gluconeogenesis serves as a secondary glycerol-production process, subsequent to exhaustion of the primary glycogenolytic source. These results provide a first look at the details of seasonal gene expression related to the production of glycerol in the mountain pine beetle.

  8. 78 kDa receptor for Man6P-independent lysosomal enzyme targeting: Biosynthetic transport from endoplasmic reticulum to 'high-density vesicles'

    International Nuclear Information System (INIS)

    Gonzalez-Noriega, Alfonso; Ortega Cuellar, Daniel D.; Michalak, Colette

    2006-01-01

    Recent work has shown that the cation-independent mannose 6-phosphate and the 78 kDa receptors for lysosomal enzyme targeting are located in different cell compartments. While the mannose 6-phosphate receptor is enriched in the Percoll fractions that contain Golgi apparatus, most of the 78 kDa receptor is localized in a heavy fraction at the bottom of the Percoll gradient. This report presents the biosynthetic transport of the 78 kDa receptor. Newly synthesized 78 kDa receptor was transported to Golgi from endoplasmic reticulum with a half life of 5 min. From the Golgi apparatus, the receptor takes two routes; about 15-25% is transported to the plasma membrane, and the rest migrates to late endosomes, subsequently to prelysosomes and finally to the dense vesicles. The 78 kDa receptor starts appearing at the dense vesicles 120 min after biosynthesis and reaches a maximum of 40-50% of the total receptor. Treatment of cells with NH 4 Cl causes depletion of the receptor from the dense vesicles and prelysosomes and corresponding augmentation in endosomes and plasma membrane. These results suggest that the 78 kDa receptor cycles between compartments and that the dense vesicles seem to represent the most distal compartment in the biosynthetic pathway of this receptor

  9. Aromatic Polyketide GTRI-02 is a Previously Unidentified Product of the act Gene Cluster in Streptomyces coelicolor A3(2).

    Science.gov (United States)

    Wu, Changsheng; Ichinose, Koji; Choi, Young Hae; van Wezel, Gilles P

    2017-07-18

    The biosynthesis of aromatic polyketides derived from type II polyketide synthases (PKSs) is complex, and it is not uncommon that highly similar gene clusters give rise to diverse structural architectures. The act biosynthetic gene cluster (BGC) of the model actinomycete Streptomyces coelicolor A3(2) is an archetypal type II PKS. Here we show that the act BGC also specifies the aromatic polyketide GTRI-02 (1) and propose a mechanism for the biogenesis of its 3,4-dihydronaphthalen-1(2H)-one backbone. Polyketide 1 was also produced by Streptomyces sp. MBT76 after activation of the act-like qin gene cluster by overexpression of the pathway-specific activator. Mining of this strain also identified dehydroxy-GTRI-02 (2), which most likely originated from dehydration of 1 during the isolation process. This work shows that even extensively studied model gene clusters such as act of S. coelicolor can still produce new chemistry, offering new perspectives for drug discovery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Cloning and expression analysis of cinnamoyl-CoA reductase (CCR) genes in sorghum.

    Science.gov (United States)

    Li, Jieqin; Fan, Feifei; Wang, Lihua; Zhan, Qiuwen; Wu, Peijin; Du, Junli; Yang, Xiaocui; Liu, Yanlong

    2016-01-01

    Cinnamoyl-CoA reductase (CCR) is the first enzyme in the monolignol-specific branch of the lignin biosynthetic pathway. In this research, three sorghum CCR genes including SbCCR1, SbCCR2-1 and SbCCR2-2 were cloned and characterized. Analyses of the structure and phylogeny of the three CCR genes showed evolutionary conservation of the functional domains and divergence of function. Transient expression assays in Nicotiana benthamiana leaves demonstrated that the three CCR proteins were localized in the cytoplasm. The expression analysis showed that the three CCR genes were induced by drought. But in 48 h, the expression levels of SbCCR1 and SbCCR2-2 did not differ between CK and the drought treatment; while the expression level of SbCCR2-1 in the drought treatment was higher than in CK. The expression of the SbCCR1 and SbCCR2-1 genes was not induced by sorghum aphid [Melanaphis sacchari (Zehntner)] attack, but SbCCR2-2 was significantly induced by sorghum aphid attack. It is suggested that SbCCR2-2 is involved in the process of pest defense. Absolute quantitative real-time PCR revealed that the three CCR genes were mainly expressed in lignin deposition organs. The gene copy number of SbCCR1 was significantly higher than those of SbCCR2-1 and SbCCR2-2 in the tested tissues, especially in stem. The results provide new insight into the functions of the three CCR genes in sorghum.

  11. Enhanced accumulation of carotenoids in sweetpotato plants overexpressing IbOr-Ins gene in purple-fleshed sweetpotato cultivar.

    Science.gov (United States)

    Park, Sung-Chul; Kim, Sun Ha; Park, Seyeon; Lee, Hyeong-Un; Lee, Joon Seol; Park, Woo Sung; Ahn, Mi-Jeong; Kim, Yun-Hee; Jeong, Jae Cheol; Lee, Haeng-Soon; Kwak, Sang-Soo

    2015-01-01

    Sweetpotato [Ipomoea batatas (L.) Lam] is an important root crop that produces low molecular weight antioxidants such as carotenoids and anthocyanin. The sweetpotato orange (IbOr) protein is involved in the accumulation of carotenoids. To increase the levels of carotenoids in the storage roots of sweetpotato, we generated transgenic sweetpotato plants overexpressing IbOr-Ins under the control of the cauliflower mosaic virus (CaMV) 35S promoter in an anthocyanin-rich purple-fleshed cultivar (referred to as IbOr plants). IbOr plants exhibited increased carotenoid levels (up to 7-fold) in their storage roots compared to wild type (WT) plants, as revealed by HPLC analysis. The carotenoid contents of IbOr plants were positively correlated with IbOr transcript levels. The levels of zeaxanthin were ∼ 12 times elevated in IbOr plants, whereas β-carotene increased ∼ 1.75 times higher than those of WT. Quantitative RT-PCR analysis revealed that most carotenoid biosynthetic pathway genes were up-regulated in the IbOr plants, including PDS, ZDS, LCY-β, CHY-β, ZEP and Pftf, whereas LCY-ɛ was down-regulated. Interestingly, CCD1, CCD4 and NCED, which are related to the degradation of carotenoids, were also up-regulated in the IbOr plants. Anthocyanin contents and transcription levels of associated biosynthetic genes seemed to be altered in the IbOr plants. The yields of storage roots and aerial parts of IbOr plants and WT plants were not significantly different under field cultivation. Taken together, these results indicate that overexpression of IbOr-Ins can increase the carotenoid contents of sweetpotato storage roots. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  12. Polymorphisms in monolignol biosynthetic genes are associated with biomass yield and agronomic traits in European maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Chen, Yongsheng; Zein, Imad; Brenner, Everton A

    2010-01-01

    Background Reduced lignin content leads to higher cell wall digestibility and, therefore, better forage quality and increased conversion of lignocellulosic biomass into ethanol. However, reduced lignin content might lead to weaker stalks, lodging, and reduced biomass yield. Genes encoding enzymes...

  13. Revelation and cloning of valinomycin synthetase genes in Streptomyces lavendulae ACR-DA1 and their expression analysis under different fermentation and elicitation conditions.

    Science.gov (United States)

    Sharma, Richa; Jamwal, Vijaylakshmi; Singh, Varun P; Wazir, Priya; Awasthi, Praveen; Singh, Deepika; Vishwakarma, Ram A; Gandhi, Sumit G; Chaubey, Asha

    2017-07-10

    Streptomyces species are amongst the most exploited microorganisms due to their ability to produce a plethora of secondary metabolites with bioactive potential, including several well known drugs. They are endowed with immense unexplored potential and substantial efforts are required for their isolation as well as characterization for their bioactive potential. Unexplored niches and extreme environments are host to diverse microbial species. In this study, we report Streptomyces lavendulae ACR-DA1, isolated from extreme cold deserts of the North Western Himalayas, which produces a macrolactone antibiotic, valinomycin. Valinomycin is a K + ionophoric non-ribosomal cyclodepsipeptide with a broad range of bioactivities including antibacterial, antifungal, antiviral and cytotoxic/anticancer activities. Production of valinomycin by the strain S. lavendulae ACR-DA1 was studied under different fermentation conditions like fermentation medium, temperature and addition of biosynthetic precursors. Synthetic medium at 10°C in the presence of precursors i.e. valine and pyruvate showed enhanced valinomycin production. In order to assess the impact of various elicitors, expression of the two genes viz. vlm1 and vlm2 that encode components of heterodimeric valinomycin synthetase, was analyzed using RT-PCR and correlated with quantity of valinomycin using LC-MS/MS. Annelid, bacterial and yeast elicitors increased valinomycin production whereas addition of fungal and plant elicitors down regulated the biosynthetic genes and reduced valinomycin production. This study is also the first report of valinomycin biosynthesis by Streptomyces lavendulae. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. New insights about antibiotic production by Pseudomonas aeruginosa: a gene expression analysis

    Science.gov (United States)

    Gionco, Bárbara; Tavares, Eliandro R.; de Oliveira, Admilton G.; Yamada-Ogatta, Sueli F.; do Carmo, Anderson O.; Pereira, Ulisses de Pádua; Chideroli, Roberta T.; Simionato, Ane S.; Navarro, Miguel O. P.; Chryssafidis, Andreas L.; Andrade, Galdino

    2017-09-01

    The bacterial resistance for antibiotics is one of the most important problems in public health and only a small number of new products are in development. Antagonistic microorganisms from soil are a promising source of new candidate molecules. Products of secondary metabolism confer adaptive advantages for their producer, in the competition for nutrients in the microbial community. The biosynthesis process of compounds with antibiotic activity is the key to optimize their production and the transcriptomic study of microorganisms is of great benefit for the discovery of these metabolic pathways. Pseudomonas aeruginosa LV strain growing in the presence of copper chloride produces a bioactive organometallic compound, which has a potent antimicrobial activity against various microorganisms. The objective of this study was to verify overexpressed genes and evaluate their relation to the organometallic biosynthesis in this microorganism. P. aeruginosa LV strain was cultured in presence and absence of copper chloride. Two methods were used for transcriptomic analysis, genome reference-guided assembly and de novo assembly. The genome referenced analysis identified nine upregulated genes when bacteria were exposed to copper chloride, while the De Novo Assembly identified twelve upregulated genes. Nineteen genes can be related to an increased microbial metabolism for the extrusion process of exceeding intracellular copper. Two important genes are related to the biosynthesis of phenazine and tetrapyrroles compounds, which can be involved in the bioremediation of intracellular copper and biosynthesis of the organometallic compound. Additional studies are being carried out to further prove the function of the described genes and relate them to the biosynthetic pathway of the organometallic compound.

  15. Modules of co-regulated metabolites in turmeric (Curcuma longa) rhizome suggest the existence of biosynthetic modules in plant specialized metabolism.

    Science.gov (United States)

    Xie, Zhengzhi; Ma, Xiaoqiang; Gang, David R

    2009-01-01

    Turmeric is an excellent example of a plant that produces large numbers of metabolites from diverse metabolic pathways or networks. It is hypothesized that these metabolic pathways or networks contain biosynthetic modules, which lead to the formation of metabolite modules-groups of metabolites whose production is co-regulated and biosynthetically linked. To test whether such co-regulated metabolite modules do exist in this plant, metabolic profiling analysis was performed on turmeric rhizome samples that were collected from 16 different growth and development treatments, which had significant impacts on the levels of 249 volatile and non-volatile metabolites that were detected. Importantly, one of the many co-regulated metabolite modules that were indeed readily detected in this analysis contained the three major curcuminoids, whereas many other structurally related diarylheptanoids belonged to separate metabolite modules, as did groups of terpenoids. The existence of these co-regulated metabolite modules supported the hypothesis that the 3-methoxyl groups on the aromatic rings of the curcuminoids are formed before the formation of the heptanoid backbone during the biosynthesis of curcumin and also suggested the involvement of multiple polyketide synthases with different substrate selectivities in the formation of the array of diarylheptanoids detected in turmeric. Similar conclusions about terpenoid biosynthesis could also be made. Thus, discovery and analysis of metabolite modules can be a powerful predictive tool in efforts to understand metabolism in plants.

  16. Reclassification of the Specialized Metabolite Producer Pseudomonas mesoacidophila ATCC 31433 as a Member of the Burkholderia cepacia Complex.

    Science.gov (United States)

    Loveridge, E Joel; Jones, Cerith; Bull, Matthew J; Moody, Suzy C; Kahl, Małgorzata W; Khan, Zainab; Neilson, Louis; Tomeva, Marina; Adams, Sarah E; Wood, Andrew C; Rodriguez-Martin, Daniel; Pinel, Ingrid; Parkhill, Julian; Mahenthiralingam, Eshwar; Crosby, John

    2017-07-01

    Pseudomonas mesoacidophila ATCC 31433 is a Gram-negative bacterium, first isolated from Japanese soil samples, that produces the monobactam isosulfazecin and the β-lactam-potentiating bulgecins. To characterize the biosynthetic potential of P. mesoacidophila ATCC 31433, its complete genome was determined using single-molecule real-time DNA sequence analysis. The 7.8-Mb genome comprised four replicons, three chromosomal (each encoding rRNA) and one plasmid. Phylogenetic analysis demonstrated that P. mesoacidophila ATCC 31433 was misclassified at the time of its deposition and is a member of the Burkholderia cepacia complex, most closely related to Burkholderia ubonensis The sequenced genome shows considerable additional biosynthetic potential; known gene clusters for malleilactone, ornibactin, isosulfazecin, alkylhydroxyquinoline, and pyrrolnitrin biosynthesis and several uncharacterized biosynthetic gene clusters for polyketides, nonribosomal peptides, and other metabolites were identified. Furthermore, P. mesoacidophila ATCC 31433 harbors many genes associated with environmental resilience and antibiotic resistance and was resistant to a range of antibiotics and metal ions. In summary, this bioactive strain should be designated B. cepacia complex strain ATCC 31433, pending further detailed taxonomic characterization. IMPORTANCE This work reports the complete genome sequence of Pseudomonas mesoacidophila ATCC 31433, a known producer of bioactive compounds. Large numbers of both known and novel biosynthetic gene clusters were identified, indicating that P. mesoacidophila ATCC 31433 is an untapped resource for discovery of novel bioactive compounds. Phylogenetic analysis demonstrated that P. mesoacidophila ATCC 31433 is in fact a member of the Burkholderia cepacia complex, most closely related to the species Burkholderia ubonensis Further investigation of the classification and biosynthetic potential of P. mesoacidophila ATCC 31433 is warranted. Copyright © 2017

  17. Insulin Biosynthetic Interaction Network Component, TMEM24, Facilitates Insulin Reserve Pool Release

    Directory of Open Access Journals (Sweden)

    Anita Pottekat

    2013-09-01

    Full Text Available Insulin homeostasis in pancreatic β cells is now recognized as a critical element in the progression of obesity and type II diabetes (T2D. Proteins that interact with insulin to direct its sequential synthesis, folding, trafficking, and packaging into reserve granules in order to manage release in response to elevated glucose remain largely unknown. Using a conformation-based approach combined with mass spectrometry, we have generated the insulin biosynthetic interaction network (insulin BIN, a proteomic roadmap in the β cell that describes the sequential interacting partners of insulin along the secretory axis. The insulin BIN revealed an abundant C2 domain-containing transmembrane protein 24 (TMEM24 that manages glucose-stimulated insulin secretion from a reserve pool of granules, a critical event impaired in patients with T2D. The identification of TMEM24 in the context of a comprehensive set of sequential insulin-binding partners provides a molecular description of the insulin secretory pathway in β cells.

  18. Molecular basis of the evolution of alternative tyrosine biosynthetic routes in plants

    Energy Technology Data Exchange (ETDEWEB)

    Schenck, Craig A.; Holland, Cynthia K.; Schneider, Matthew R.; Men, Yusen; Lee, Soon Goo; Jez, Joseph M.; Maeda , Hiroshi A. (UW); (WU)

    2017-06-26

    L-Tyrosine (Tyr) is essential for protein synthesis and is a precursor of numerous specialized metabolites crucial for plant and human health. Tyr can be synthesized via two alternative routes by different key regulatory TyrA family enzymes, prephenate dehydrogenase (PDH, also known as TyrAp) or arogenate dehydrogenase (ADH, also known as TyrAa), representing a unique divergence of primary metabolic pathways. The molecular foundation underlying the evolution of these alternative Tyr pathways is currently unknown. Here we characterized recently diverged plant PDH and ADH enzymes, obtained the X-ray crystal structure of soybean PDH, and identified a single amino acid residue that defines TyrA substrate specificity and regulation. Structures of mutated PDHs co-crystallized with Tyr indicate that substitutions of Asn222 confer ADH activity and Tyr sensitivity. Reciprocal mutagenesis of the corresponding residue in divergent plant ADHs further introduced PDH activity and relaxed Tyr sensitivity, highlighting the critical role of this residue in TyrA substrate specificity that underlies the evolution of alternative Tyr biosynthetic pathways in plants.

  19. Sex pheromone biosynthetic pathways are conserved between moths and the butterfly Bicyclus anynana

    Science.gov (United States)

    Liénard, Marjorie A; Wang, Hong-Lei; Lassance, Jean-Marc; Löfstedt, Christer

    2014-01-01

    Although phylogenetically nested within the moths, butterflies have diverged extensively in a number of life history traits. Whereas moths rely greatly on chemical signals, visual advertisement is the hallmark of mate finding in butterflies. In the context of courtship, however, male chemical signals are widespread in both groups although they likely have multiple evolutionary origins. Here, we report that in males of the butterfly Bicyclus anynana, courtship scents are produced de novo via biosynthetic pathways shared with females of many moth species. We show that two of the pheromone components that play a major role in mate choice, namely the (Z)-9-tetradecenol and hexadecanal, are produced through the activity of a fatty acyl Δ11-desaturase and two specialized alcohol-forming fatty acyl reductases. Our study provides the first evidence of conservation and sharing of ancestral genetic modules for the production of FA-derived pheromones over a long evolutionary timeframe thereby reconciling mate communication in moths and butterflies. PMID:24862548

  20. Biosynthetic pathway of the phytohormone auxin in insects and screening of its inhibitors.

    Science.gov (United States)

    Suzuki, Hiroyoshi; Yokokura, Junpei; Ito, Tsukasa; Arai, Ryoma; Yokoyama, Chiaki; Toshima, Hiroaki; Nagata, Shinji; Asami, Tadao; Suzuki, Yoshihito

    2014-10-01

    Insect galls are abnormal plant tissues induced by galling insects. The galls are used for food and habitation, and the phytohormone auxin, produced by the insects, may be involved in their formation. We found that the silkworm, a non-galling insect, also produces an active form of auxin, indole-3-acetic acid (IAA), by de novo synthesis from tryptophan (Trp). A detailed metabolic analysis of IAA using IAA synthetic enzymes from silkworms indicated an IAA biosynthetic pathway composed of a three-step conversion: Trp → indole-3-acetaldoxime → indole-3-acetaldehyde (IAAld) → IAA, of which the first step is limiting IAA production. This pathway was shown to also operate in gall-inducing sawfly. Screening of a chemical library identified two compounds that showed strong inhibitory activities on the conversion step IAAld → IAA. The inhibitors can be efficiently used to demonstrate the importance of insect-synthesized auxin in gall formation in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. RNA-Seq mediated root transcriptome analysis of Chlorophytum borivilianum for identification of genes involved in saponin biosynthesis.

    Science.gov (United States)

    Kumar, Sunil; Kalra, Shikha; Singh, Baljinder; Kumar, Avneesh; Kaur, Jagdeep; Singh, Kashmir

    2016-01-01

    Chlorophytum borivilianum is an important species of liliaceae family, owing to its vital medicinal properties. Plant roots are used for aphrodisiac, adaptogen, anti-aging, health-restorative and health-promoting purposes. Saponins, are considered to be the principal bioactive components responsible for the wide variety of pharmacological properties of this plant. In the present study, we have performed de novo root transcriptome sequencing of C. borivilianum using Illumina Hiseq 2000 platform, to gain molecular insight into saponins biosynthesis. A total of 33,963,356 high-quality reads were obtained after quality filtration. Sequences were assembled using various programs which generated 97,344 transcripts with a size range of 100-5,216 bp and N50 value of 342. Data was analyzed against non-redundant proteins, gene ontology (GO), and enzyme commission (EC) databases. All the genes involved in saponins biosynthesis along with five full-length genes namely farnesyl pyrophosphate synthase, cycloartenol synthase, β-amyrin synthase, cytochrome p450, and sterol-3-glucosyltransferase were identified. Read per exon kilobase per million (RPKM)-based comparative expression profiling was done to study the differential regulation of the genes. In silico expression analysis of seven selected genes of saponin biosynthetic pathway was validated by qRT-PCR.

  2. The Presence of Two Cyclase Thioesterases Expands the Conformational Freedom of the Cyclic Peptide Occidiofungin

    Science.gov (United States)

    Ravichandran, Akshaya; Gu, Ganyu; Escano, Jerome; Lu, Shi-En; Smith, Leif

    2014-01-01

    Occidiofungin is a cyclic nonribosomally synthesized antifungal peptide with submicromolar activity produced by Gram-negative bacterium Burkholderia contaminans. The biosynthetic gene cluster was confirmed to contain two cyclase thioesterases. NMR analysis revealed that the presence of both thioesterases is used to increase the conformational repertoire of the cyclic peptide. The loss of the OcfN cyclic thioesterase by mutagenesis results in a reduction of conformational variants and an appreciable decrease in bioactivity against Candida species. Presumably, the presence of both asparagine and β-hydroxyasparagine variants coordinate the enzymatic function of both of the cyclase thioesterases. OcfN has presumably evolved to be part of the biosynthetic gene cluster due to its ability to produce structural variants that enhance antifungal activity against some fungi. The enhancement of the antifungal activity from the incorporation of an additional cyclase thioesterase into the biosynthetic gene cluster of occidiofungin supports the need to explore new conformational variants of other therapeutic or potentially therapeutic cyclic peptides. PMID:23394257

  3. Diet-Gene Interactions and PUFA Metabolism: A Potential Contributor to Health Disparities and Human Diseases

    Directory of Open Access Journals (Sweden)

    Floyd H. Chilton

    2014-05-01

    Full Text Available The “modern western” diet (MWD has increased the onset and progression of chronic human diseases as qualitatively and quantitatively maladaptive dietary components give rise to obesity and destructive gene-diet interactions. There has been a three-fold increase in dietary levels of the omega-6 (n-6 18 carbon (C18, polyunsaturated fatty acid (PUFA linoleic acid (LA; 18:2n-6, with the addition of cooking oils and processed foods to the MWD. Intense debate has emerged regarding the impact of this increase on human health. Recent studies have uncovered population-related genetic variation in the LCPUFA biosynthetic pathway (especially within the fatty acid desaturase gene (FADS cluster that is associated with levels of circulating and tissue PUFAs and several biomarkers and clinical endpoints of cardiovascular disease (CVD. Importantly, populations of African descent have higher frequencies of variants associated with elevated levels of arachidonic acid (ARA, CVD biomarkers and disease endpoints. Additionally, nutrigenomic interactions between dietary n-6 PUFAs and variants in genes that encode for enzymes that mobilize and metabolize ARA to eicosanoids have been identified. These observations raise important questions of whether gene-PUFA interactions are differentially driving the risk of cardiovascular and other diseases in diverse populations, and contributing to health disparities, especially in African American populations.

  4. Global identification of the full-length transcripts and alternative splicing related to phenolic acid biosynthetic genes in Salvia miltiorrhiza

    Directory of Open Access Journals (Sweden)

    Zhichao eXu

    2016-02-01

    Full Text Available Salvianolic acids are among the main bioactive components in Salvia miltiorrhiza, and their biosynthesis has attracted widespread interest. However, previous studies on the biosynthesis of phenolic acids using next-generation sequencing platforms are limited with regard to the assembly of full-length transcripts. Based on hybrid-seq (next-generation and single molecular real-time sequencing of the S. miltiorrhiza root transcriptome, we experimentally identified 15 full-length transcripts and 4 alternative splicing events of enzyme-coding genes involved in the biosynthesis of rosmarinic acid. Moreover, we herein demonstrate that lithospermic acid B accumulates in the phloem and xylem of roots, in agreement with the expression patterns of the identified key genes related to rosmarinic acid biosynthesis. According to co-expression patterns, we predicted that 6 candidate cytochrome P450s and 5 candidate laccases participate in the salvianolic acid pathway. Our results provide a valuable resource for further investigation into the synthetic biology of phenolic acids in S. miltiorrhiza.

  5. Stress-caused Anergy of Leukocytes towards Staphylococcal enterotoxin B and Exposure Transcriptome Signatures

    Science.gov (United States)

    2015-05-28

    concerted immune depletion was highly pronounced in the case of genes involved in synthesis /secretion of chemokines and antigen presentation. (c) The 21...biosynthetic process 48545 8.03E-03 12 Response to steroid hormone stimulus 16126 9.50E-03 5 Sterol biosynthetic process 6950 1.01E-02 44 Response to

  6. Widespread occurrence of secondary lipid biosynthesis potential in microbial lineages.

    Directory of Open Access Journals (Sweden)

    Christine N Shulse

    Full Text Available Bacterial production of long-chain omega-3 polyunsaturated fatty acids (PUFAs, such as eicosapentaenoic acid (EPA, 20:5n-3 and docosahexaenoic acid (DHA, 22:6n-3, is constrained to a narrow subset of marine γ-proteobacteria. The genes responsible for de novo bacterial PUFA biosynthesis, designated pfaEABCD, encode large, multi-domain protein complexes akin to type I iterative fatty acid and polyketide synthases, herein referred to as "Pfa synthases". In addition to the archetypal Pfa synthase gene products from marine bacteria, we have identified homologous type I FAS/PKS gene clusters in diverse microbial lineages spanning 45 genera representing 10 phyla, presumed to be involved in long-chain fatty acid biosynthesis. In total, 20 distinct types of gene clusters were identified. Collectively, we propose the designation of "secondary lipids" to describe these biosynthetic pathways and products, a proposition consistent with the "secondary metabolite" vernacular. Phylogenomic analysis reveals a high degree of functional conservation within distinct biosynthetic pathways. Incongruence between secondary lipid synthase functional clades and taxonomic group membership combined with the lack of orthologous gene clusters in closely related strains suggests horizontal gene transfer has contributed to the dissemination of specialized lipid biosynthetic activities across disparate microbial lineages.

  7. Weighted gene co-expression network analysis of expression data of monozygotic twins identifies specific modules and hub genes related to BMI.

    Science.gov (United States)

    Wang, Weijing; Jiang, Wenjie; Hou, Lin; Duan, Haiping; Wu, Yili; Xu, Chunsheng; Tan, Qihua; Li, Shuxia; Zhang, Dongfeng

    2017-11-13

    The therapeutic management of obesity is challenging, hence further elucidating the underlying mechanisms of obesity development and identifying new diagnostic biomarkers and therapeutic targets are urgent and necessary. Here, we performed differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) to identify significant genes and specific modules related to BMI based on gene expression profile data of 7 discordant monozygotic twins. In the differential gene expression analysis, it appeared that 32 differentially expressed genes (DEGs) were with a trend of up-regulation in twins with higher BMI when compared to their siblings. Categories of positive regulation of nitric-oxide synthase biosynthetic process, positive regulation of NF-kappa B import into nucleus, and peroxidase activity were significantly enriched within GO database and NF-kappa B signaling pathway within KEGG database. DEGs of NAMPT, TLR9, PTGS2, HBD, and PCSK1N might be associated with obesity. In the WGCNA, among the total 20 distinct co-expression modules identified, coral1 module (68 genes) had the strongest positive correlation with BMI (r = 0.56, P = 0.04) and disease status (r = 0.56, P = 0.04). Categories of positive regulation of phospholipase activity, high-density lipoprotein particle clearance, chylomicron remnant clearance, reverse cholesterol transport, intermediate-density lipoprotein particle, chylomicron, low-density lipoprotein particle, very-low-density lipoprotein particle, voltage-gated potassium channel complex, cholesterol transporter activity, and neuropeptide hormone activity were significantly enriched within GO database for this module. And alcoholism and cell adhesion molecules pathways were significantly enriched within KEGG database. Several hub genes, such as GAL, ASB9, NPPB, TBX2, IL17C, APOE, ABCG4, and APOC2 were also identified. The module eigengene of saddlebrown module (212 genes) was also significantly

  8. Cloning and expression analysis of two dehydrodolichyl diphosphate synthase genes from Tripterygium wilfordii

    Directory of Open Access Journals (Sweden)

    Lin-Hui Gao

    2018-01-01

    Full Text Available Objective: To clone and investigate two dehydrodolichyl diphosphate synthase genes of Tripterygium wilfordii by bioinformatics and tissue expression analysis. Materials and Methods: According to the T. wifordii transcriptome database, specific primers were designed to clone the TwDHDDS1 and TwDHDDS2 genes via PCR. Based on the cloned sequences, protein structure prediction, multiple sequence alignment and phylogenetic tree construction were performed. The expression levels of the genes in different tissues of T. wilfordii were measured by real-time quantitative PCR. Results: The TwDHDDS1 gene encompassed a 873 bp open reading frame (ORF and encoded a protein of 290 amino acids. The calculated molecular weight of the translated protein was about 33.46 kDa, and the theoretical isoelectric point (pI was 8.67. The TwDHDDS2 encompassed a 768 bp ORF, encoding a protein of 255 amino acids with a calculated molecular weight of about 21.19 kDa, and a theoretical isoelectric point (pI of 7.72. Plant tissue expression analysis indicated that TwDHDDS1 and TwDHDDS2 both have relatively ubiquitous expression in all sampled organ tissues, but showed the highest transcription levels in the stems. Conclusions: The results of this study provide a basis for further functional studies of TwDHDDS1 and TwDHDDS2. Most importantly, these genes are promising genetic targets for the regulation of the biosynthetic pathways of important bioactive terpenoids such as triptolide.

  9. Arctic mustard flower color polymorphism controlled by petal-specific downregulation at the threshold of the anthocyanin biosynthetic pathway.

    Directory of Open Access Journals (Sweden)

    Cynthia A Dick

    2011-04-01

    Full Text Available Intra- and interspecific variation in flower color is a hallmark of angiosperm diversity. The evolutionary forces underlying the variety of flower colors can be nearly as diverse as the colors themselves. In addition to pollinator preferences, non-pollinator agents of selection can have a major influence on the evolution of flower color polymorphisms, especially when the pigments in question are also expressed in vegetative tissues. In such cases, identifying the target(s of selection starts with determining the biochemical and molecular basis for the flower color variation and examining any pleiotropic effects manifested in vegetative tissues. Herein, we describe a widespread purple-white flower color polymorphism in the mustard Parrya nudicaulis spanning Alaska. The frequency of white-flowered individuals increases with increasing growing-season temperature, consistent with the role of anthocyanin pigments in stress tolerance. White petals fail to produce the stress responsive flavonoid intermediates in the anthocyanin biosynthetic pathway (ABP, suggesting an early pathway blockage. Petal cDNA sequences did not reveal blockages in any of the eight enzyme-coding genes in white-flowered individuals, nor any color differentiating SNPs. A qRT-PCR analysis of white petals identified a 24-fold reduction in chalcone synthase (CHS at the threshold of the ABP, but no change in CHS expression in leaves and sepals. This arctic species has avoided the deleterious effects associated with the loss of flavonoid intermediates in vegetative tissues by decoupling CHS expression in petals and leaves, yet the correlation of flower color and climate suggests that the loss of flavonoids in the petals alone may affect the tolerance of white-flowered individuals to colder environments.

  10. Weighted Gene Co-expression Network Analysis of the Dioscin Rich Medicinal Plant Dioscorea nipponica

    Directory of Open Access Journals (Sweden)

    Wei Sun

    2017-06-01

    Full Text Available Dioscorea contains critically important species which can be used as staple foods or sources of bioactive substances, including Dioscorea nipponica, which has been used to develop highly successful drugs to treat cardiovascular disease. Its major active ingredients are thought to be sterol compounds such as diosgenin, which has been called “medicinal gold” because of its valuable properties. However, reliance on naturally growing plants as a production system limits the potential use of D. nipponica, raising interest in engineering metabolic pathways to enhance the production of secondary metabolites. However, the biosynthetic pathway of diosgenin is still poorly understood, and D. nipponica is poorly characterized at a molecular level, hindering in-depth investigation. In the present work, the RNAs from five organs and seven methyl jasmonate treated D. nipponica rhizomes were sequenced using the Illumina high-throughput sequencing platform, yielding 52 gigabases of data, which were pooled and assembled into a reference transcriptome. Four hundred and eighty two genes were found to be highly expressed in the rhizomes, and these genes are mainly involved in stress response and transcriptional regulation. Based on their expression patterns, 36 genes were selected for further investigation as candidate genes involved in dioscin biosynthesis. Constructing co-expression networks based on significant changes in gene expression revealed 15 gene modules. Of these, four modules with properties correlating to dioscin regulation and biosynthesis, consisting of 4,665 genes in total, were selected for further functional investigation. These results improve our understanding of dioscin biosynthesis in this important medicinal plant and will help guide more intensive investigations.

  11. Gene activation by UV light, fungal elicitor or fungal infection in Petroselinum crispum is correlated with repression of cell cycle-related genes

    International Nuclear Information System (INIS)

    Logemann, E.; Wu ShengCheng; Schröder, J.; Schmelzer, E.; Somssich, I.E.; Hahlbrock, K.

    1995-01-01

    The effects of UV light or fungal elicitors on plant cells have so far been studied mostly with respect to defense-related gene activation. Here, an inverse correlation of these stimulatory effects with the activities of several cell cycle-related genes is demonstrated. Concomitant with the induction of flavonoid biosynthetic enzymes in UV-irradiated cell suspension cultures of parsley (Petroselinum crispum), total histone synthesis declined to about half the initial rate. A subclass of the histone H3 gene family was selected to demonstrate the close correlation of its expression with cell division, both in intact plants and cultured cells. Using RNA-blot and run-on transcription assays, it was shown that one arbitrarily selected subclass of each of the histone H2A, H2B, H3 and H4 gene families and of the genes encoding a p34cdc2 protein kinase and a mitotic cyclin were transcriptionally repressed in UV-irradiated as well as fungal elicitor-treated parsley cells. The timing and extent of repression differed between the two stimuli; the response to light was more transient and smaller in magnitude. These differential responses to light and elicitor were inversely correlated with the induction of phenylalanine ammonia-lyase, a key enzyme of phenylpropanoid metabolism. Essentially the same result was obtained with a defined oligopeptide elicitor, indicating that the same signaling pathway is responsible for defense-related gene activation and cell cycle-related gene repression. A temporary (UV light) or long-lasting (fungal elicitor) cessation of cell culture growth is most likely due to an arrest of cell division which may be a prerequisite for full commitment of the cells to transcriptional activation of full commitment of the cells to transcriptional activation of pathways involved in UV protection or pathogen defense. This conclusion is corroborated by the observation that the histone H3 mRNA level greatly declined around fungal infection sites in young parsley

  12. Molecular characterization and functional analysis of chalcone synthase from Syringa oblata Lindl. in the flavonoid biosynthetic pathway.

    Science.gov (United States)

    Wang, Yu; Dou, Ying; Wang, Rui; Guan, Xuelian; Hu, Zenghui; Zheng, Jian

    2017-11-30

    The flower color of Syringa oblata Lindl., which is often modulated by the flavonoid content, varies and is an important ornamental feature. Chalcone synthase (CHS) catalyzes the first key step in the flavonoid biosynthetic pathway. However, little is known about the role of S. oblata CHS (SoCHS) in flavonoid biosynthesis in this species. Here, we isolate and analyze the cDNA (SoCHS1) that encodes CHS in S. oblata. We also sought to analyzed the molecular characteristics and function of flavonoid metabolism by SoCHS1. We successfully isolated the CHS-encoding genomic DNA (gDNA) in S. oblata (SoCHS1), and the gene structural analysis indicated it had no intron. The opening reading frame (ORF) sequence of SoCHS1 was 1170bp long and encoded a 389-amino acid polypeptide. Multiple sequence alignment revealed that both the conserved CHS active site residues and CHS signature sequence were in the deduced amino acid sequence of SoCHS1. Crystallographic analysis revealed that the protein structure of SoCHS1 is highly similar to that of FnCHS1 in Freesia hybrida. The quantitative real-time polymerase chain reaction (PCR) performed to detect the SoCHS1 transcript expression levels in flowers, and other tissues revealed the expression was significantly correlated with anthocyanin accumulation during flower development. The ectopic expression results of Nicotiana tabacum showed that SoCHS1 overexpression in transgenic tobacco changed the flower color from pale pink to pink. In conclusion, these results suggest that SoCHS1 plays an essential role in flavonoid biosynthesis in S. oblata, and could be used to modify flavonoid components in other plant species. Copyright © 2017. Published by Elsevier B.V.

  13. Molecular interaction of the first 3 enzymes of the de novo pyrimidine biosynthetic pathway of Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Nara, Takeshi; Hashimoto, Muneaki; Hirawake, Hiroko; Liao, Chien-Wei; Fukai, Yoshihisa; Suzuki, Shigeo; Tsubouchi, Akiko; Morales, Jorge; Takamiya, Shinzaburo; Fujimura, Tsutomu; Taka, Hikari; Mineki, Reiko; Fan, Chia-Kwung; Inaoka, Daniel Ken; Inoue, Masayuki; Tanaka, Akiko; Harada, Shigeharu; Kita, Kiyoshi

    2012-01-01

    Highlights: ► An Escherichia coli strain co-expressing CPSII, ATC, and DHO of Trypanosoma cruzi was constructed. ► Molecular interactions between CPSII, ATC, and DHO of T. cruzi were demonstrated. ► CPSII bound with both ATC and DHO. ► ATC bound with both CPSII and DHO. ► A functional tri-enzyme complex might precede the establishment of the fused enzyme. -- Abstract: The first 3 reaction steps of the de novo pyrimidine biosynthetic pathway are catalyzed by carbamoyl-phosphate synthetase II (CPSII), aspartate transcarbamoylase (ATC), and dihydroorotase (DHO), respectively. In eukaryotes, these enzymes are structurally classified into 2 types: (1) a CPSII-DHO-ATC fusion enzyme (CAD) found in animals, fungi, and amoebozoa, and (2) stand-alone enzymes found in plants and the protist groups. In the present study, we demonstrate direct intermolecular interactions between CPSII, ATC, and DHO of the parasitic protist Trypanosoma cruzi, which is the causative agent of Chagas disease. The 3 enzymes were expressed in a bacterial expression system and their interactions were examined. Immunoprecipitation using an antibody specific for each enzyme coupled with Western blotting-based detection using antibodies for the counterpart enzymes showed co-precipitation of all 3 enzymes. From an evolutionary viewpoint, the formation of a functional tri-enzyme complex may have preceded—and led to—gene fusion to produce the CAD protein. This is the first report to demonstrate the structural basis of these 3 enzymes as a model of CAD. Moreover, in conjunction with the essentiality of de novo pyrimidine biosynthesis in the parasite, our findings provide a rationale for new strategies for developing drugs for Chagas disease, which target the intermolecular interactions of these 3 enzymes.

  14. Identification of the pheromone biosynthesis genes from the sex pheromone gland transcriptome of the diamondback moth, Plutella xylostella.

    Science.gov (United States)

    Chen, Da-Song; Dai, Jian-Qing; Han, Shi-Chou

    2017-11-24

    The diamondback moth was estimated to increase costs to the global agricultural economy as the global area increase of Brassica vegetable crops and oilseed rape. Sex pheromones traps are outstanding tools available in Integrated Pest Management for many years and provides an effective approach for DBM population monitoring and control. The ratio of two major sex pheromone compounds shows geographical variations. However, the limitation of our information in the DBM pheromone biosynthesis dampens our understanding of the ratio diversity of pheromone compounds. Here, we constructed a transcriptomic library from the DBM pheromone gland and identified genes putatively involved in the fatty acid biosynthesis, pheromones functional group transfer, and β-oxidation enzymes. In addition, odorant binding protein, chemosensory protein and pheromone binding protein genes encoded in the pheromone gland transcriptome, suggest that female DBM moths may receive odors or pheromone compounds via their pheromone gland and ovipositor system. Tissue expression profiles further revealed that two ALR, three DES and one FAR5 genes were pheromone gland tissue biased, while some chemoreception genes expressed extensively in PG, pupa, antenna and legs tissues. Finally, the candidate genes from large-scale transcriptome information may be useful for characterizing a presumed biosynthetic pathway of the DBM sex pheromone.

  15. Differential expression of carotenoid biosynthetic pathway genes in ...

    Indian Academy of Sciences (India)

    2016-04-08

    Pandurangaiah S, Ravishankar KV, Shivashankar KS, Sadashiva AT, Pillakenchappa K and Narayanan SK ... development and validation of LCY-B and CYC-B in selected contrasting F2 plants (red ripe fruits) derived from the cross.

  16. Expression profile of genes coding for carotenoid biosynthetic ...

    Indian Academy of Sciences (India)

    Fruit ripening process is associated with change in carotenoid profile and accumulation of lycopene in tomato (Solanum lycopersicum L.). In this study, we quantified the -carotene and lycopene content at green, breaker and red-ripe stages of fruit ripening in eight tomato genotypes by using high-performance liquid ...

  17. Biosynthetic Studies of 13-Desmethylspirolide C Produced by Alexandrium ostenfeldii (= A. peruvianum): Rationalization of the Biosynthetic Pathway Following Incorporation of (13)C-Labeled Methionine and Application of the Odd-Even Rule of Methylation.

    Science.gov (United States)

    Anttila, Matthew; Strangman, Wendy; York, Robert; Tomas, Carmelo; Wright, Jeffrey L C

    2016-03-25

    Understanding the biosynthesis of dinoflagellate polyketides presents many unique challenges. Because of the remaining hurdles to dinoflagellate genome sequencing, precursor labeling studies remain the only viable way to investigate dinoflagellate biosynthesis. However, prior studies have shown that polyketide chain assembly does not follow any of the established processes. Additionally, acetate, the common precursor for polyketides, is frequently scrambled, thus compromising interpretation. These factors are further compounded by low production yields of the compounds of interest. A recent report on the biosynthesis of spirolides, a group belonging to the growing class of toxic spiroimines, provided some insight into the polyketide assembly process based on acetate labeling studies, but many details were left uncertain. By feeding (13)C methyl-labeled methionine to cultures of Alexandrium ostenfeldii, the producing organism of 13-desmethylspirolide C, and application of the odd-even methylation rule, the complete biosynthetic pathway has been established.

  18. Comparative glandular trichome transcriptome-based gene characterization reveals reasons for differential (-)-menthol biosynthesis in Mentha species.

    Science.gov (United States)

    Akhtar, Md Qussen; Qamar, Nida; Yadav, Pallavi; Kulkarni, Pallavi; Kumar, Ajay; Shasany, Ajit Kumar

    2017-06-01

    The genes involved in menthol biosynthesis are reported earlier in Mentha × piperita. But the information on these genes is not available in Mentha arvensis. To bridge the gap in knowledge on differential biosynthesis of monoterpenes leading to compositional variation in the essential oil of these species, a comparative transcriptome analysis of the glandular trichome (GT) was carried out. In addition to the mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathway genes, about 210 and 196 different terpene synthases (TPSs) transcripts were identified from annotation in M. arvensis and M. × piperita, respectively, and correlated to several monoterpenes present in the essential oil. Six isoforms of (-)-menthol dehydrogenases (MD), the last enzyme of the menthol biosynthetic pathway, were identified, cloned and characterized from the transcriptome data (three from each species). Varied expression levels and differential enzyme kinetics of these isoforms indicated the nature and composition of the product, as these isoforms generate both (-)-menthol and (+)-neomenthol from (-)-menthone and converts (-)-menthol to (-)-menthone in the reverse reaction, and hence together determine the quantity of (-)-menthol in the essential oil in these two species. Several genes for high value minor monoterpenes could also be identified from the transcriptome data. © 2017 Scandinavian Plant Physiology Society.

  19. Identification of key pathways and genes influencing prognosis in bladder urothelial carcinoma

    Directory of Open Access Journals (Sweden)

    Ning X

    2017-03-01

    Full Text Available Xin Ning, Yaoliang Deng Department of Urology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Province, People’s Republic of China Background: Genomic profiling can be used to identify the predictive effect of genomic subsets for determining prognosis in bladder urothelial carcinoma (BUC after radical cystectomy. This study aimed to investigate potential gene and pathway markers associated with prognosis in BUC.Methods: A microarray dataset of BUC was obtained from The Cancer Genome Atlas database. Differentially expressed genes (DEGs were identified by DESeq of the R platform. Kaplan–Meier analysis was applied for prognostic markers. Key pathways and genes were identified using bioinformatics tools, such as gene set enrichment analysis, gene ontology, the Kyoto Encyclopedia of Genes and Genomes, gene multiple association network integration algorithm (GeneMANIA, Search Tool for the Retrieval of Interacting Genes/Proteins, and Molecular Complex Detection.Results: A comparative gene set enrichment analysis of tumor and adjacent normal tissues suggested BUC tumorigenesis resulted mainly from enrichment of cell cycle and DNA damage and repair-related biological processes and pathways, including TP53 and mitotic recombination. Two hundred and fifty-six genes were identified as potential prognosis-related DEGs. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that the potential prognosis-related DEGs were enriched in angiogenesis, including the cyclic adenosine monophosphate biosynthetic process, cyclic guanosine monophosphate-protein kinase G, mitogen-activated protein kinase, Rap1, and phosphoinositide-3-kinase-AKT signaling pathway. Nine hub genes, TAGLN, ACTA2, MYH11, CALD1, MYLK, GEM, PRELP, TPM2, and OGN, were identified from the intersection of protein–protein interaction and GeneMANIA networks. Module analysis of protein–protein interaction and GeneMANIA networks mainly showed

  20. Pleiotropic regulatory genes bldA, adpA and absB are implicated in production of phosphoglycolipid antibiotic moenomycin.

    Science.gov (United States)

    Makitrynskyy, Roman; Ostash, Bohdan; Tsypik, Olga; Rebets, Yuriy; Doud, Emma; Meredith, Timothy; Luzhetskyy, Andriy; Bechthold, Andreas; Walker, Suzanne; Fedorenko, Victor

    2013-10-23

    Unlike the majority of actinomycete secondary metabolic pathways, the biosynthesis of peptidoglycan glycosyltransferase inhibitor moenomycin in Streptomyces ghanaensis does not involve any cluster-situated regulators (CSRs). This raises questions about the regulatory signals that initiate and sustain moenomycin production. We now show that three pleiotropic regulatory genes for Streptomyces morphogenesis and antibiotic production-bldA, adpA and absB-exert multi-layered control over moenomycin biosynthesis in native and heterologous producers. The bldA gene for tRNA(Leu)UAA is required for the translation of rare UUA codons within two key moenomycin biosynthetic genes (moe), moeO5 and moeE5. It also indirectly influences moenomycin production by controlling the translation of the UUA-containing adpA and, probably, other as-yet-unknown repressor gene(s). AdpA binds key moe promoters and activates them. Furthermore, AdpA interacts with the bldA promoter, thus impacting translation of bldA-dependent mRNAs-that of adpA and several moe genes. Both adpA expression and moenomycin production are increased in an absB-deficient background, most probably because AbsB normally limits adpA mRNA abundance through ribonucleolytic cleavage. Our work highlights an underappreciated strategy for secondary metabolism regulation, in which the interaction between structural genes and pleiotropic regulators is not mediated by CSRs. This strategy might be relevant for a growing number of CSR-free gene clusters unearthed during actinomycete genome mining.

  1. LRP1 controls biosynthetic and endocytic trafficking of neuronal prion protein

    DEFF Research Database (Denmark)

    Parkyn, Celia J; Vermeulen, Esmeralda G M; Mootoosamy, Roy C

    2008-01-01

    The trafficking of normal cellular prion protein (PrP(C)) is believed to control its conversion to the altered conformation (designated PrP(Sc)) associated with prion disease. Although anchored to the membrane by means of glycosylphosphatidylinositol (GPI), PrP(C) on neurons is rapidly and consti......The trafficking of normal cellular prion protein (PrP(C)) is believed to control its conversion to the altered conformation (designated PrP(Sc)) associated with prion disease. Although anchored to the membrane by means of glycosylphosphatidylinositol (GPI), PrP(C) on neurons is rapidly...... required for this process. Moreover, sustained inhibition of LRP1 levels by siRNA leads to the accumulation of PrP(C) in biosynthetic compartments, with a concomitant lowering of surface PrP(C), suggesting that LRP1 expedites the trafficking of PrP(C) to the neuronal surface. PrP(C) and LRP1 can be co......-immunoprecipitated from the endoplasmic reticulum in normal neurons. The N-terminal domain of PrP(C) binds to purified human LRP1 with nanomolar affinity, even in the presence of 1 microM of the LRP-specific chaperone, receptor-associated protein (RAP). Taken together, these data argue that LRP1 controls both the surface...

  2. New Insights about Antibiotic Production by Pseudomonas aeruginosa: A Gene Expression Analysis

    Directory of Open Access Journals (Sweden)

    Bárbara Gionco

    2017-09-01

    Full Text Available The bacterial resistance for antibiotics is one of the most important problems in public health and only a small number of new products are in development. Antagonistic microorganisms from soil are a promising source of new candidate molecules. Products of secondary metabolism confer adaptive advantages for their producer, in the competition for nutrients in the microbial community. The biosynthesis process of compounds with antibiotic activity is the key to optimize their production and the transcriptomic study of microorganisms is of great benefit for the discovery of these metabolic pathways. Pseudomonas aeruginosa LV strain growing in the presence of copper chloride produces a bioactive organometallic compound, which has a potent antimicrobial activity against various microorganisms. The objective of this study was to verify overexpressed genes and evaluate their relation to the organometallic biosynthesis in this microorganism. P. aeruginosa LV strain was cultured in presence and absence of copper chloride. Two methods were used for transcriptomic analysis, genome reference-guided assembly and de novo assembly. The genome referenced analysis identified nine upregulated genes when bacteria were exposed to copper chloride, while the De Novo Assembly identified 12 upregulated genes. Nineteen genes can be related to an increased microbial metabolism for the extrusion process of exceeding intracellular copper. Two important genes are related to the biosynthesis of phenazine and tetrapyrroles compounds, which can be involved in the bioremediation of intracellular copper and we suggesting that may involve in the biosynthesis of the organometallic compound. Additional studies are being carried out to further prove the function of the described genes and relate them to the biosynthetic pathway of the organometallic compound.

  3. The rice YABBY4 gene regulates plant growth and development through modulating the gibberellin pathway.

    Science.gov (United States)

    Yang, Chao; Ma, Yamei; Li, Jianxiong

    2016-10-01

    YABBY genes encode seed plant-specific transcription factors that play pivotal roles in diverse aspects of leaf, shoot, and flower development. Members of the YABBY gene family are primarily expressed in lateral organs in a polar manner and function to specify abaxial cell fate in dicotyledons, but this polar expression is not conserved in monocotyledons. The function of YABBY genes is therefore not well understood in monocotyledons. Here we show that overexpression of the rice (Oryza sativa L.) YABBY4 gene (OsYABBY4) leads to a semi-dwarf phenotype, abnormal development in the uppermost internode, an increased number of floral organs, and insensitivity to gibberellin (GA) treatment. We report on an important role for OsYABBY4 in negative control of the expression of a GA biosynthetic gene by binding to the promoter region of the gibberellin 20-oxidase 2 gene (GA20ox2), which is a direct target of SLR1 (the sole DELLA protein negatively controlling GA responses in rice). OsYABBY4 also suppresses the expression level of SLR1 and interacts with SLR1 protein. The interaction inhibits GA-dependent degradation of SLR1 and therefore leads to GA insensitivity. These data together suggest that OsYABBY4 serves as a DNA-binding intermediate protein for SLR1 and is associated with the GA signaling pathway regulating gene expression during plant growth and development. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Sesquiterpene Synthase-3-Hydroxy-3-Methylglutaryl Coenzyme A Synthase Fusion Protein Responsible for Hirsutene Biosynthesis in Stereum hirsutum.

    Science.gov (United States)

    Flynn, Christopher M; Schmidt-Dannert, Claudia

    2018-06-01

    The wood-rotting mushroom Stereum hirsutum is a known producer of a large number of namesake hirsutenoids, many with important bioactivities. Hirsutenoids form a structurally diverse and distinct class of sesquiterpenoids. No genes involved in hirsutenoid biosynthesis have yet been identified or their enzymes characterized. Here, we describe the cloning and functional characterization of a hirsutene synthase as an unexpected fusion protein of a sesquiterpene synthase (STS) with a C-terminal 3-hydroxy-3-methylglutaryl-coenzyme A (3-hydroxy-3-methylglutaryl-CoA) synthase (HMGS) domain. Both the full-length fusion protein and truncated STS domain are highly product-specific 1,11-cyclizing STS enzymes with kinetic properties typical of STSs. Complementation studies in Saccharomyces cerevisiae confirmed that the HMGS domain is also functional in vivo Phylogenetic analysis shows that the hirsutene synthase domain does not form a clade with other previously characterized sesquiterpene synthases from Basidiomycota. Comparative gene structure analysis of this hirsutene synthase with characterized fungal enzymes reveals a significantly higher intron density, suggesting that this enzyme may be acquired by horizontal gene transfer. In contrast, the HMGS domain is clearly related to other fungal homologs. This STS-HMGS fusion protein is part of a biosynthetic gene cluster that includes P450s and oxidases that are expressed and could be cloned from cDNA. Finally, this unusual fusion of a terpene synthase to an HMGS domain, which is not generally recognized as a key regulatory enzyme of the mevalonate isoprenoid precursor pathway, led to the identification of additional HMGS duplications in many fungal genomes, including the localization of HMGSs in other predicted sesquiterpenoid biosynthetic gene clusters. IMPORTANCE Hirsutenoids represent a structurally diverse class of bioactive sesquiterpenoids isolated from fungi. Identification of their biosynthetic pathways will provide

  5. Transformation of Aspergillus parasiticus with a homologous gene (pyrG) involved in pyrimidine biosynthesis

    International Nuclear Information System (INIS)

    Skory, C.D.; Horng, J.S.; Pestka, J.J.; Linz, J.E.

    1990-01-01

    The lack of efficient transformation methods for aflatoxigenic Aspergillus parasiticus has been a major constraint for the study of aflatoxin biosynthesis at the genetic level. A transformation system with efficiencies of 30 to 50 stable transformants per μg of DNA was developed for A. parasiticus by using homologous pyrG gene. The pyrG gene from A. parasiticus was isolated by in situ plaque hybridization of a lambda genomic DNA library. Uridine auxotrophs of A. parasiticus ATCC 36537, a mutant blocked in aflatoxin biosynthesis, were isolated by selection on 5-fluoroorotic acid following nitrosoguanidine mutagenesis. Isolates with mutations in the pyrG gene resulting in elimination of orotidine monophosphate (OMP) decarboxylase activity were detected by assaying cell extracts for their ability to convert [ 14 C]OMP to [ 14 C]UMP. Transformation of A. parasiticus pyrG protoplasts with the homologous pyrG gene restored the fungal cells to prototrophy. Enzymatic analysis of cell extracts of transformant clones demonstrated that these extracts had the ability to convert [ 14 C]OMP to [ 14 C]UMP. Southern analysis of DNA purified from transformant clones indicated that both pUC19 vector sequences and pyrG sequences were integrated into the genome. The development of this pyrG transformation system should allow cloning of the aflatoxin-biosynthetic genes, which will be useful in studying the regulation of aflatoxin biosynthesis and may ultimately provide a means for controlling aflatoxin production in the field

  6. Application of a Colorimetric Assay to Identify Putative Ribofuranosylaminobenzene 5'-Phosphate Synthase Genes Expressed with Activity in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Bechard Matthew E.

    2003-01-01

    Full Text Available Tetrahydromethanopterin (H4MPT is a tetrahydrofolate analog originally discovered in methanogenic archaea, but later found in other archaea and bacteria. The extent to which H4MPT occurs among living organisms is unknown. The key enzyme which distinguishes the biosynthetic pathways of H4MPT and tetrahydrofolate is ribofuranosylaminobenzene 5'-phosphate synthase (RFAP synthase. Given the importance of RFAP synthase in H4MPT biosynthesis, the identification of putative RFAP synthase genes and measurement of RFAP synthase activity would provide an indication of the presence of H4MPT in untested microorganisms. Investigation of putative archaeal RFAP synthase genes has been hampered by the tendency of the resulting proteins to form inactive inclusion bodies in Escherichia coli. The current work describes a colorimetric assay for measuring RFAP synthase activity, and two modified procedures for expressing recombinant RFAP synthase genes to produce soluble, active enzyme. By lowering the incubation temperature during expression, RFAP synthase from Archaeoglobus fulgidus was produced in E. coli and purified to homogeneity. The production of active RFAP synthase from Methanothermobacter thermautotrophicus was achieved by coexpression of the gene MTH0830 with a molecular chaperone. This is the first direct biochemical identification of a methanogen gene that codes for an active RFAP synthase.

  7. Application of a Colorimetric Assay to Identify Putative Ribofuranosylaminobenzene 5'-Phosphate Synthase Genes Expressed with Activity in Escherichia coli.

    Science.gov (United States)

    Bechard, Matthew E.; Chhatwal, Sonya; Garcia, Rosemarie E.; Rasche, Madeline E.

    2003-01-01

    Tetrahydromethanopterin (H(4)MPT) is a tetrahydrofolate analog originally discovered in methanogenic archaea, but later found in other archaea and bacteria. The extent to which H(4)MPT occurs among living organisms is unknown. The key enzyme which distinguishes the biosynthetic pathways of H(4)MPT and tetrahydrofolate is ribofuranosylaminobenzene 5'-phosphate synthase (RFAP synthase). Given the importance of RFAP synthase in H(4)MPT biosynthesis, the identification of putative RFAP synthase genes and measurement of RFAP synthase activity would provide an indication of the presence of H(4)MPT in untested microorganisms. Investigation of putative archaeal RFAP synthase genes has been hampered by the tendency of the resulting proteins to form inactive inclusion bodies in Escherichia coli. The current work describes a colorimetric assay for measuring RFAP synthase activity, and two modified procedures for expressing recombinant RFAP synthase genes to produce soluble, active enzyme. By lowering the incubation temperature during expression, RFAP synthase from Archaeoglobus fulgidus was produced in E. coli and purified to homogeneity. The production of active RFAP synthase from Methanothermobacter thermautotrophicus was achieved by coexpression of the gene MTH0830 with a molecular chaperone. This is the first direct biochemical identification of a methanogen gene that codes for an active RFAP synthase.

  8. Molecular cloning and expression analysis of three omega-6 desaturase genes from purslane (Portulaca oleracea L.).

    Science.gov (United States)

    Teixeira, M C; Coelho, N; Olsson, M E; Brodelius, P E; Carvalho, I S; Brodelius, M

    2009-07-01

    Two full-length cDNA clones of PoleFAD2 and one full-length cDNA clone of PoleFAD6, encoding omega-6 fatty acid desaturases, the key enzymes for the conversion of oleic into linoleic acid, were isolated from purslane (Portulaca oleracea L.) leaves and seeds. The deduced amino acid sequence of both isoforms of PoleFAD2 showed higher similarities to other microsomal omega-6 desaturases then to PoleFAD6 or other plastidial orthologues, and vice versa. Expression analysis by RT-PCR showed that all genes are expressed in all tissues of purslane tested, but higher levels of mRNA accumulation were detected in reproductive organs and cells that proliferate rapidly or store lipids. Wounding affected the levels of mRNA accumulation of both, FAD2 and FAD6 genes in purslane leaves, while chilling stress affected only FAD2 transcript level. The expression patterns observed reflect the discrete roles of these genes in membrane synthesis for cell division, thylakoid development, and lipid storage or in the biosynthetic pathway for the production of signaling molecules that influence plant development or defense.

  9. Identification and functional analysis of gene cluster involvement in biosynthesis of the cyclic lipopeptide antibiotic pelgipeptin produced by Paenibacillus elgii

    Directory of Open Access Journals (Sweden)

    Qian Chao-Dong

    2012-09-01

    Full Text Available Abstract Background Pelgipeptin, a potent antibacterial and antifungal agent, is a non-ribosomally synthesised lipopeptide antibiotic. This compound consists of a β-hydroxy fatty acid and nine amino acids. To date, there is no information about its biosynthetic pathway. Results A potential pelgipeptin synthetase gene cluster (plp was identified from Paenibacillus elgii B69 through genome analysis. The gene cluster spans 40.8 kb with eight open reading frames. Among the genes in this cluster, three large genes, plpD, plpE, and plpF, were shown to encode non-ribosomal peptide synthetases (NRPSs, with one, seven, and one module(s, respectively. Bioinformatic analysis of the substrate specificity of all nine adenylation domains indicated that the sequence of the NRPS modules is well collinear with the order of amino acids in pelgipeptin. Additional biochemical analysis of four recombinant adenylation domains (PlpD A1, PlpE A1, PlpE A3, and PlpF A1 provided further evidence that the plp gene cluster involved in pelgipeptin biosynthesis. Conclusions In this study, a gene cluster (plp responsible for the biosynthesis of pelgipeptin was identified from the genome sequence of Paenibacillus elgii B69. The identification of the plp gene cluster provides an opportunity to develop novel lipopeptide antibiotics by genetic engineering.

  10. Functional gene polymorphism to reveal species history: the case of the CRTISO gene in cultivated carrots.

    Directory of Open Access Journals (Sweden)

    Vanessa Soufflet-Freslon

    Full Text Available Carrot is a vegetable cultivated worldwide for the consumption of its root. Historical data indicate that root colour has been differentially selected over time and according to geographical areas. Root pigmentation depends on the relative proportion of different carotenoids for the white, yellow, orange and red types but only internally for the purple one. The genetic control for root carotenoid content might be partially associated with carotenoid biosynthetic genes. Carotenoid isomerase (CRTISO has emerged as a regulatory step in the carotenoid biosynthesis pathway and could be a good candidate to show how a metabolic pathway gene reflects a species genetic history.In this study, the nucleotide polymorphism and the linkage disequilibrium among the complete CRTISO sequence, and the deviation from neutral expectation were analysed by considering population subdivision revealed with 17 microsatellite markers. A sample of 39 accessions, which represented different geographical origins and root colours, was used. Cultivated carrot was divided into two genetic groups: one from Middle East and Asia (Eastern group, and another one mainly from Europe (Western group. The Western and Eastern genetic groups were suggested to be differentially affected by selection: a signature of balancing selection was detected within the first group whereas the second one showed no selection. A focus on orange-rooted carrots revealed that cultivars cultivated in Asia were mainly assigned to the Western group but showed CRTISO haplotypes common to Eastern carrots.The carotenoid pathway CRTISO gene data proved to be complementary to neutral markers in order to bring critical insight in the cultivated carrot history. We confirmed the occurrence of two migration events since domestication. Our results showed a European background in material from Japan and Central Asia. While confirming the introduction of European carrots in Japanese resources, the history of Central Asia

  11. [Gastro-entero anastomosis with flexible endoscope with the help of rare-earth magnets on biosynthetic model made of the gastrointestinal tract of slaughtered pigs].

    Science.gov (United States)

    Lukovich, Péter; Jónás, Attila; Bata, Pál; Tari, Krisztina; Váradi, Gábor; Kádár, Balázs; Mehdi, Sadat Akhavi; Kupcsulik, Péter

    2007-04-01

    Gastro-entero anastomosis with flexible endoscope with the help of rare-earth magnets on biosynthetic model made of the gastrointestinal tract of slaughtered pigs Numerous malignant diseases may cause gastric outlet obstruction. The surgical gastrointestinal bypass, besides the fact that it requires narcosis, is also associated with high risks for patients with poor general condition. Endoscopic insertion of self-expandable metal stent is less invasive, but often causes complications. In the last years some studies examined a new minimal invasive technique, in which magnets are used to create gastroenteric anastomosis. A biosynthetic model was developed from combined synthetic materials with biogenic specimens taken from slaughtered domestic pigs. The procedure was performed with endoscopic and fluoroscopic guidance. To increase X-ray contrast differences the model was put into physiological saline solution. Two rare-earth magnets (Br: 2500 Gauss, D: 10 mm) with central hole were inserted with the help of a guiding wire and duodenal probe. The first magnet was placed in the first jejunal loop; the second one was placed in the stomach. The gastric magnet was maneuvered using the endoscope. When the magnets reached the right position, the guiding wires were removed to let the magnets stick together. The pressure between the magnets will result in a sterile inflammation on the living tissue which develops adhesion between the bowels, and 7-10 days later anastomosis will develop as a result of the necrosis. The biosynthetic model could be used for training endoscopy without sacrificing animals. In the end of the procedure the magnets stuck together across gastric and jejunal walls in all ten cases successfully. By practice the period necessary for the procedure could be decreased from 40 to 20 minutes. The technique could be made with standard upper endoscope and instruments, and after practice on living animals it could potentially be a useful solution for complaints

  12. Overexpression of the IbMYB1 gene in an orange-fleshed sweet potato cultivar produces a dual-pigmented transgenic sweet potato with improved antioxidant activity.

    Science.gov (United States)

    Park, Sung-Chul; Kim, Yun-Hee; Kim, Sun Ha; Jeong, Yu Jeong; Kim, Cha Young; Lee, Joon Seol; Bae, Ji-Yeong; Ahn, Mi-Jeong; Jeong, Jae Cheol; Lee, Haeng-Soon; Kwak, Sang-Soo

    2015-04-01

    The R2R3-type protein IbMYB1 is a key regulator of anthocyanin biosynthesis in the storage roots of sweet potato [Ipomoea batatas (L.) Lam]. Previously, we demonstrated that IbMYB1 expression stimulated anthocyanin pigmentation in tobacco leaves and Arabidopsis. Here, we generated dual-pigmented transgenic sweet potato plants that accumulated high levels of both anthocyanins and carotenoids in a single sweet potato storage root. An orange-fleshed cultivar with high carotenoid levels was transformed with the IbMYB1 gene under the control of either the storage root-specific sporamin 1 (SPO1) promoter or the oxidative stress-inducible peroxidase anionic 2 (SWPA2) promoter. The SPO1-MYB transgenic lines exhibited higher anthocyanin levels in storage roots than empty vector control (EV) or SWPA2-MYB plants, but carotenoid content was unchanged. SWPA2-MYB transgenic lines exhibited higher levels of both anthocyanin and carotenoids than EV plants. Analysis of hydrolyzed anthocyanin extracts indicated that cyanidin and peonidin predominated in both overexpression lines. Quantitative reverse transcription-polymerase chain reaction analysis demonstrated that IbMYB1 expression in both IbMYB1 transgenic lines strongly induced the upregulation of several genes in the anthocyanin biosynthetic pathway, whereas the expression of carotenoid biosynthetic pathway genes varied between transgenic lines. Increased anthocyanin levels in transgenic plants also promoted the elevation of proanthocyanidin and total phenolic levels in fresh storage roots. Consequently, all IbMYB1 transgenic plants displayed much higher antioxidant activities than EV plants. In field cultivations, storage root yields varied between the transgenic lines. Taken together, our results indicate that overexpression of IbMYB1 is a highly promising strategy for the generation of transgenic plants with enhanced antioxidant capacity. © 2014 Scandinavian Plant Physiology Society.

  13. The Intracellular Localization of the Vanillin Biosynthetic Machinery in Pods of Vanilla planifolia.

    Science.gov (United States)

    Gallage, Nethaji J; Jørgensen, Kirsten; Janfelt, Christian; Nielsen, Agnieszka J Z; Naake, Thomas; Dunski, Eryk; Dalsten, Lene; Grisoni, Michel; Møller, Birger Lindberg

    2018-02-01

    Vanillin is the most important flavor compound in the vanilla pod. Vanilla planifolia vanillin synthase (VpVAN) catalyzes the conversion of ferulic acid and ferulic acid glucoside into vanillin and vanillin glucoside, respectively. Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) of vanilla pod sections demonstrates that vanillin glucoside is preferentially localized within the mesocarp and placental laminae whereas vanillin is preferentially localized within the mesocarp. VpVAN is present as the mature form (25 kDa) but, depending on the tissue and isolation procedure, small amounts of the immature unprocessed form (40 kDa) and putative oligomers (50, 75 and 100 kDa) may be observed by immunoblotting using an antibody specific to the C-terminal sequence of VpVAN. The VpVAN protein is localized within chloroplasts and re-differentiated chloroplasts termed phenyloplasts, as monitored during the process of pod development. Isolated chloroplasts were shown to convert [14C]phenylalanine and [14C]cinnamic acid into [14C]vanillin glucoside, indicating that the entire vanillin de novo biosynthetic machinery converting phenylalanine to vanillin glucoside is present in the chloroplast.

  14. Juvenile hormone biosynthesis gene expression in the corpora allata of honey bee (Apis mellifera L. female castes.

    Directory of Open Access Journals (Sweden)

    Ana Durvalina Bomtorin

    Full Text Available Juvenile hormone (JH controls key events in the honey bee life cycle, viz. caste development and age polyethism. We quantified transcript abundance of 24 genes involved in the JH biosynthetic pathway in the corpora allata-corpora cardiaca (CA-CC complex. The expression of six of these genes showing relatively high transcript abundance was contrasted with CA size, hemolymph JH titer, as well as JH degradation rates and JH esterase (jhe transcript levels. Gene expression did not match the contrasting JH titers in queen and worker fourth instar larvae, but jhe transcript abundance and JH degradation rates were significantly lower in queen larvae. Consequently, transcriptional control of JHE is of importance in regulating larval JH titers and caste development. In contrast, the same analyses applied to adult worker bees allowed us inferring that the high JH levels in foragers are due to increased JH synthesis. Upon RNAi-mediated silencing of the methyl farnesoate epoxidase gene (mfe encoding the enzyme that catalyzes methyl farnesoate-to-JH conversion, the JH titer was decreased, thus corroborating that JH titer regulation in adult honey bees depends on this final JH biosynthesis step. The molecular pathway differences underlying JH titer regulation in larval caste development versus adult age polyethism lead us to propose that mfe and jhe genes be assayed when addressing questions on the role(s of JH in social evolution.

  15. Juvenile hormone biosynthesis gene expression in the corpora allata of honey bee (Apis mellifera L.) female castes.

    Science.gov (United States)

    Bomtorin, Ana Durvalina; Mackert, Aline; Rosa, Gustavo Conrado Couto; Moda, Livia Maria; Martins, Juliana Ramos; Bitondi, Márcia Maria Gentile; Hartfelder, Klaus; Simões, Zilá Luz Paulino

    2014-01-01

    Juvenile hormone (JH) controls key events in the honey bee life cycle, viz. caste development and age polyethism. We quantified transcript abundance of 24 genes involved in the JH biosynthetic pathway in the corpora allata-corpora cardiaca (CA-CC) complex. The expression of six of these genes showing relatively high transcript abundance was contrasted with CA size, hemolymph JH titer, as well as JH degradation rates and JH esterase (jhe) transcript levels. Gene expression did not match the contrasting JH titers in queen and worker fourth instar larvae, but jhe transcript abundance and JH degradation rates were significantly lower in queen larvae. Consequently, transcriptional control of JHE is of importance in regulating larval JH titers and caste development. In contrast, the same analyses applied to adult worker bees allowed us inferring that the high JH levels in foragers are due to increased JH synthesis. Upon RNAi-mediated silencing of the methyl farnesoate epoxidase gene (mfe) encoding the enzyme that catalyzes methyl farnesoate-to-JH conversion, the JH titer was decreased, thus corroborating that JH titer regulation in adult honey bees depends on this final JH biosynthesis step. The molecular pathway differences underlying JH titer regulation in larval caste development versus adult age polyethism lead us to propose that mfe and jhe genes be assayed when addressing questions on the role(s) of JH in social evolution.

  16. EPA, DHA, and Lipoic Acid Differentially Modulate the n-3 Fatty Acid Biosynthetic Pathway in Atlantic Salmon Hepatocytes.

    Science.gov (United States)

    Bou, Marta; Østbye, Tone-Kari; Berge, Gerd M; Ruyter, Bente

    2017-03-01

    The aim of the present study was to investigate how EPA, DHA, and lipoic acid (LA) influence the different metabolic steps in the n-3 fatty acid (FA) biosynthetic pathway in hepatocytes from Atlantic salmon fed four dietary levels (0, 0.5, 1.0 and 2.0%) of EPA, DHA or a 1:1 mixture of these FA. The hepatocytes were incubated with [1- 14 C] 18:3n-3 in the presence or absence of LA (0.2 mM). Increased endogenous levels of EPA and/or DHA and LA exposure both led to similar responses in cells with reduced desaturation and elongation of [1- 14 C] 18:3n-3 to 18:4n-3, 20:4n-3, and EPA, in agreement with reduced expression of the Δ6 desaturase gene involved in the first step of conversion. DHA production, on the other hand, was maintained even in groups with high endogenous levels of DHA, possibly due to a more complex regulation of this last step in the n-3 metabolic pathway. Inhibition of the Δ6 desaturase pathway led to increased direct elongation to 20:3n-3 by both DHA and LA. Possibly the route by 20:3n-3 and then Δ8 desaturation to 20:4n-3, bypassing the first Δ6 desaturase step, can partly explain the maintained or even increased levels of DHA production. LA increased DHA production in the phospholipid fraction of hepatocytes isolated from fish fed 0 and 0.5% EPA and/or DHA, indicating that LA has the potential to further increase the production of this health-beneficial FA in fish fed diets with low levels of EPA and/or DHA.

  17. Gene Expression Profiling in the Pituitary Gland of Laying Period and Ceased Period Huoyan Geese

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    Xinhong Luan

    2013-07-01

    Full Text Available Huoyan goose is a Chinese local breed famous for its higher laying performance, but the problems of variety degeneration have emerged recently, especially a decrease in the number of eggs laid. In order to better understand the molecular mechanism that underlies egg laying in Huoyan geese, gene profiles in the pituitary gland of Huoyan geese taken during the laying period and ceased period were investigated using the suppression subtractive hybridization (SSH method. Total RNA was extracted from pituitary glands of ceased period and laying period geese. The cDNA in the pituitary glands of ceased geese was subtracted from the cDNA in the pituitary glands of laying geese (forward subtraction; the reverse subtraction was also performed. After sequencing and annotation, a total of 30 and 24 up and down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These genes mostly related to biosynthetic process, cellular nitrogen compound metabolic process, transport, cell differentiation, cellular protein modification process, signal transduction, small molecule metabolic process. Furthermore, eleven genes were selected for further analyses by quantitative real-time PCR (qRT-PCR. The qRT-PCR results for the most part were consistent with the SSH results. Among these genes, Synaptotagmin-1 (SYT1 and Stathmin-2 (STMN2 were substantially over-expressed in laying period compared to ceased period. These results could serve as an important reference for elucidating the molecular mechanism of higher laying performance in Huoyan geese.

  18. Comparative genomics and evolution of eukaryotic phospholipidbiosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lykidis, Athanasios

    2006-12-01

    Phospholipid biosynthetic enzymes produce diverse molecular structures and are often present in multiple forms encoded by different genes. This work utilizes comparative genomics and phylogenetics for exploring the distribution, structure and evolution of phospholipid biosynthetic genes and pathways in 26 eukaryotic genomes. Although the basic structure of the pathways was formed early in eukaryotic evolution, the emerging picture indicates that individual enzyme families followed unique evolutionary courses. For example, choline and ethanolamine kinases and cytidylyltransferases emerged in ancestral eukaryotes, whereas, multiple forms of the corresponding phosphatidyltransferases evolved mainly in a lineage specific manner. Furthermore, several unicellular eukaryotes maintain bacterial-type enzymes and reactions for the synthesis of phosphatidylglycerol and cardiolipin. Also, base-exchange phosphatidylserine synthases are widespread and ancestral enzymes. The multiplicity of phospholipid biosynthetic enzymes has been largely generated by gene expansion in a lineage specific manner. Thus, these observations suggest that phospholipid biosynthesis has been an actively evolving system. Finally, comparative genomic analysis indicates the existence of novel phosphatidyltransferases and provides a candidate for the uncharacterized eukaryotic phosphatidylglycerol phosphate phosphatase.

  19. In silico analysis highlights the frequency and diversity of type 1 lantibiotic gene clusters in genome sequenced bacteria

    LENUS (Irish Health Repository)

    Marsh, Alan J

    2010-11-30

    Abstract Background Lantibiotics are lanthionine-containing, post-translationally modified antimicrobial peptides. These peptides have significant, but largely untapped, potential as preservatives and chemotherapeutic agents. Type 1 lantibiotics are those in which lanthionine residues are introduced into the structural peptide (LanA) through the activity of separate lanthionine dehydratase (LanB) and lanthionine synthetase (LanC) enzymes. Here we take advantage of the conserved nature of LanC enzymes to devise an in silico approach to identify potential lantibiotic-encoding gene clusters in genome sequenced bacteria. Results In total 49 novel type 1 lantibiotic clusters were identified which unexpectedly were associated with species, genera and even phyla of bacteria which have not previously been associated with lantibiotic production. Conclusions Multiple type 1 lantibiotic gene clusters were identified at a frequency that suggests that these antimicrobials are much more widespread than previously thought. These clusters represent a rich repository which can yield a large number of valuable novel antimicrobials and biosynthetic enzymes.

  20. A R2R3-MYB transcription factor from Epimedium sagittatum regulates the flavonoid biosynthetic pathway.

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    Wenjun Huang

    Full Text Available Herba epimedii (Epimedium, a traditional Chinese medicine, has been widely used as a kidney tonic and antirheumatic medicine for thousands of years. The bioactive components in herba epimedii are mainly prenylated flavonol glycosides, end-products of the flavonoid pathway. Epimedium species are also used as garden plants due to the colorful flowers and leaves. Many R2R3-MYB transcription factors (TFs have been identified to regulate the flavonoid and anthocyanin biosynthetic pathways. However, little is known about the R2R3-MYB TFs involved in regulation of the flavonoid pathway in Epimedium. Here, we reported the isolation and functional characterization of the first R2R3-MYB TF (EsMYBA1 from Epimedium sagittatum (Sieb. Et Zucc. Maxim. Conserved domains and phylogenetic analysis showed that EsMYBA1 belonged to the subgroup 6 clade (anthocyanin-related MYB clade of R2R3-MYB family, which includes Arabidopsis AtPAP1, apple MdMYB10 and legume MtLAP1. EsMYBA1 was preferentially expressed in leaves, especially in red leaves that contain higher content of anthocyanin. Alternative splicing of EsMYBA1 resulted in three transcripts and two of them encoded a MYB-related protein. Yeast two-hybrid and transient luciferase expression assay showed that EsMYBA1 can interact with several bHLH regulators of the flavonoid pathway and activate the promoters of dihydroflavonol 4-reductase (DFR and anthocyanidin synthase (ANS. In both transgenic tobacco and Arabidopsis, overexpression of EsMYBA1 induced strong anthocyanin accumulation in reproductive and/or vegetative tissues via up-regulation of the main flavonoid-related genes. Furthermore, transient expression of EsMYBA1 in E. sagittatum leaves by Agrobacterium infiltration also induced anthocyanin accumulation in the wounded area. This first functional characterization of R2R3-MYB TFs in Epimedium species will promote further studies of the flavonoid biosynthesis and regulation in medicinal plants.