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Sample records for biosynthesis distinguish roots

  1. Fatty acid biosynthesis in pea root plastids

    International Nuclear Information System (INIS)

    Stahl, R.J.; Sparace, S.A.

    1989-01-01

    Fatty acid biosynthesis from [1- 14 C]acetate was optimized in plastids isolated from primary root tips of 7-day-old germinating pea seeds. Fatty acid synthesis was maximum at approximately 80 nmoles/hr/mg protein in the presence of 200 μM acetate, 0.5 mM each of NADH, NADPH and CoA, 6 mM each of ATP and MgCl 2 , 1 mM each of the MnCl 2 and glycerol-3-phosphate, 15 mM KHCO 3 , and 0.1M Bis-tris-propane, pH 8.0 incubated at 35C. At the standard incubation temperature of 25C, fatty acid synthesis was linear from up to 6 hours with 80 to 100 μg/mL plastid protein. ATP and CoA were absolute requirements, whereas KHCO 3 , divalent cations and reduced nucleotides all improved activity by 80 to 85%. Mg 2+ and NADH were the preferred cation and nucleotide, respectively. Dithiothreitol and detergents were generally inhibitory. The radioactive products of fatty acid biosynthesis were approximately 33% 16:0, 10% 18:0 and 56% 18:1 and generally did not vary with increasing concentrations of each cofactor

  2. Sites and regulation of auxin biosynthesis in Arabidopsis roots.

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    Ljung, Karin; Hull, Anna K; Celenza, John; Yamada, Masashi; Estelle, Mark; Normanly, Jennifer; Sandberg, Göran

    2005-04-01

    Auxin has been shown to be important for many aspects of root development, including initiation and emergence of lateral roots, patterning of the root apical meristem, gravitropism, and root elongation. Auxin biosynthesis occurs in both aerial portions of the plant and in roots; thus, the auxin required for root development could come from either source, or both. To monitor putative internal sites of auxin synthesis in the root, a method for measuring indole-3-acetic acid (IAA) biosynthesis with tissue resolution was developed. We monitored IAA synthesis in 0.5- to 2-mm sections of Arabidopsis thaliana roots and were able to identify an important auxin source in the meristematic region of the primary root tip as well as in the tips of emerged lateral roots. Lower but significant synthesis capacity was observed in tissues upward from the tip, showing that the root contains multiple auxin sources. Root-localized IAA synthesis was diminished in a cyp79B2 cyp79B3 double knockout, suggesting an important role for Trp-dependent IAA synthesis pathways in the root. We present a model for how the primary root is supplied with auxin during early seedling development.

  3. Biosynthesis of sterols and ecdysteroids in Ajuga hairy roots.

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    Fujimoto, Y; Ohyama, K; Nomura, K; Hyodo, R; Takahashi, K; Yamada, J; Morisaki, M

    2000-03-01

    Hairy roots of Ajuga reptans var. atropurpurea produce clerosterol, 22-dehydroclerosterol, and cholesterol as sterol constituents, and 20-hydroxyecdysone, cyasterone, isocyasterone, and 29-norcyasterone as ecdysteroid constituents. To better understand the biosynthesis of these steroidal compounds, we carried out feeding studies of variously 2H- and 13C-labeled sterol substrates with Ajuga hairy roots. In this article, we review our studies in this field. Feeding of labeled desmosterols, 24-methylenecholesterol, and 13C2-acetate established the mechanism of the biosynthesis of the two C29-sterols and a newly accumulated codisterol, including the metabolic correlation of C-26 and C-27 methyl groups. In Ajuga hairy roots, 3alpha-, 4alpha-, and 4beta-hydrogens of cholesterol were all retained at their original positions after conversion into 20-hydroxyecdysone, in contrast to the observations in a fern and an insect. Furthermore, the origin of 5beta-H of 20-hydroxyecdysone was found to be C-6 hydrogen of cholesterol exclusively, which is inconsistent with the results in the fern and the insect. These data strongly support the intermediacy of 7-dehydrocholesterol 5alpha,6alpha-epoxide. Moreover, 7-dehydrocholesterol, 3beta-hydroxy-5beta-cholest-7-en-6-one (5beta-ketol), and 3beta,14alpha-dihydroxy-5beta-cholest-7-en-6-one (5beta-ketodiol) were converted into 20-hydroxyecdysone. Thus, the pathway cholesterol-->7-dehydrocholesterol-->7-dehydrocholesterol 5alpha,6alpha-epoxide-->5beta-ketol-->5beta-k etodiol is proposed for the early stages of 20-hydroxyecdysone biosynthesis. 3beta-Hydroxy-5beta-cholestan-6-one was also incorporated into 20-hydroxyecdysone, suggesting that the introduction of a 7-ene function is not necessarily next to cholesterol. C-25 Hydroxylation during 20-hydroxyecdysone biosynthesis was found to proceed with ca. 70% retention and 30% inversion. Finally, clerosterol was shown to be a precursor of cyasterone and isocyasterone.

  4. Asparagine Biosynthesis in Alfalfa (Medicago sativa L.) Root Nodules.

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    Snapp, S S; Vance, C P

    1986-10-01

    Rapid direct conversion of exogenously supplied [(14)C]aspartate to [(14)C] asparagine and to tricarboxylic cycle acids was observed in alfalfa (Medicago sativa L.) nodules. Aspartate aminotransferase activity readily converted carbon from exogenously applied [(14)C]aspartate into the tricarboxylic acid cycle with subsequent conversion to the organic acids malate, succinate, and fumarate. Aminooxyacetate, an inhibitor of aminotransferase activity, reduced the flow of carbon from [(14)C]aspartate into tricarboxylic cycle acids and decreased (14)CO(2) evolution by 99%. Concurrently, maximum conversion of aspartate to asparagine was observed in aminooxyacetate treated nodules (30 nanomoles asparagine per gram fresh weight per hour. Metabolism of [(14)C]aspartate and distribution of nodulefixed (14)CO(2) suggest that two pools of aspartate occur in alfalfa nodules: (a) one involved in asparagine biosynthesis, and (b) another supplying a malate/aspartate shuttle. Conversion of [(14)C]aspartate to [(14)C]asparagine was not inhibited by methionine sulfoximine, a glutamine synthetase inhibitor, or azaserine, a glutmate synthetase, inhibitor. The data did not indicate that asparagine biosynthesis in alfalfa nodules has an absolute requirement for glutamine. Radioactivity in the xylem sap, derived from nodule (14)CO(2) fixation, was markedly decreased by treating nodulated roots with aminooxyacetate, methionine sulfoximine, and azaserine. Inhibitors decreased the [(14)C]aspartate and [(14)]asparagine content of xylem sap by greater than 80% and reduced the total amino nitrogen content of xylem sap (including nonradiolabeled amino acids) by 50 to 80%. Asparagine biosynthesis in alfalfa nodules and transport in xylem sap are dependent upon continued aminotransferase activity and an uninterrupted assimilation of ammonia via the glutamine synthetase/glutamate synthase pathway. Continued assimilation of ammonia apparently appears crucial to continued root nodule CO(2) fixation in

  5. Hyoscyamine biosynthesis in Datura stramonium hairy root in vitro systems with different ploidy levels.

    Science.gov (United States)

    Pavlov, A; Berkov, S; Weber, J; Bley, Th

    2009-05-01

    Hyoscyamine biosynthesis in Datura stramonium hairy roots with different ploidy levels was investigated. For the first time, we report that hairy roots undergo endoreduplication and therefore consist mainly of cells with doupled sets of chromosomes of primary plant tissues, used for Agrobacterium transformation. The alkaloid profiles of hairy roots obtained from diploid and tetraploid plants were similar in terms of the major compounds, but they differed significantly with respect to the minor compounds (here defined as those that accounted for stramonium hairy root cultures are also presented.

  6. Biosynthesis of anthraquinone derivatives in a Sesamum indicum hairy root culture.

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    Furumoto, Toshio; Sato, Ryuta

    2017-10-01

    In order to investigate the intermediacy of 2-(4-methylpent-3-en-1-yl)anthraquinone (MPAQ), a possible intermediate for the biosynthesis of anthraquinone derivatives in sesame (Sesamum indicum), 2 H-labeled MPAQ was administered to a hairy root culture of S. indicum. Efficient conversion of fed MPAQ to 2-[(Z)-4-methylpenta-1,3-dien-1-yl]anthraquinone ((Z)-MPDEAQ) was observed. Furthermore, administration experiment with 2 H-labeled 2-geranyl-1,4-naphthohydroquinone, another possible intermediate, showed that it was converted to MPAQ and (Z)-MPDEAQ. The results clearly demonstrated that these substrates are the actual precursors for the production of (Z)-MPDEAQ. In contrast, neither MPAQ nor 2-geranyl-1,4-naphthohydroquinone was converted to anthrasesamone B and 2,3-epoxyanthrasesamone B, other anthraquinone derivatives in the hairy roots, suggesting that these substrates may not be the common precursors in the biosynthesis of anthraquinone derivatives.

  7. Comprehensive Characterization for Ginsenosides Biosynthesis in Ginseng Root by Integration Analysis of Chemical and Transcriptome

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    Jing-Jing Zhang

    2017-05-01

    Full Text Available Herbgenomics provides a global platform to explore the genetics and biology of herbs on the genome level. Panax ginseng C.A. Meyer is an important medicinal plant with numerous pharmaceutical effects. Previous reports mainly discussed the transcriptome of ginseng at the organ level. However, based on mass spectrometry imaging analyses, the ginsenosides varied among different tissues. In this work, ginseng root was separated into three tissues—periderm, cortex and stele—each for five duplicates. The chemical analysis and transcriptome analysis were conducted simultaneously. Gene-encoding enzymes involved in ginsenosides biosynthesis and modification were studied based on gene and molecule data. Eight widely-used ginsenosides were distributed unevenly in ginseng roots. A total of 182,881 unigenes were assembled with an N50 contig size of 1374 bp. About 21,000 of these unigenes were positively correlated with the content of ginsenosides. Additionally, we identified 192 transcripts encoding enzymes involved in two triterpenoid biosynthesis pathways and 290 transcripts encoding UDP-glycosyltransferases (UGTs. Of these UGTs, 195 UGTs (67.2% were more highly expressed in the periderm, and that seven UGTs and one UGT were specifically expressed in the periderm and stele, respectively. This genetic resource will help to improve the interpretation on complex mechanisms of ginsenosides biosynthesis, accumulation, and transportation.

  8. Transcriptional profiling of sweetpotato (Ipomoea batatas) roots indicates down-regulation of lignin biosynthesis and up-regulation of starch biosynthesis at an early stage of storage root formation.

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    Firon, Nurit; LaBonte, Don; Villordon, Arthur; Kfir, Yanir; Solis, Julio; Lapis, Evgenia; Perlman, Temima Schnitzer; Doron-Faigenboim, Adi; Hetzroni, Amots; Althan, Leviah; Adani Nadir, Lahan

    2013-07-09

    The number of fibrous roots that develop into storage roots determines sweetpotato yield. The aim of the present study was to identify the molecular mechanisms involved in the initiation of storage root formation, by performing a detailed transcriptomic analysis of initiating storage roots using next-generation sequencing platforms. A two-step approach was undertaken: (1) generating a database for the sweetpotato root transcriptome using 454-Roche sequencing of a cDNA library created from pooled samples of two root types: fibrous and initiating storage roots; (2) comparing the expression profiles of initiating storage roots and fibrous roots, using the Illumina Genome Analyzer to sequence cDNA libraries of the two root types and map the data onto the root transcriptome database. Use of the 454-Roche platform generated a total of 524,607 reads, 85.6% of which were clustered into 55,296 contigs that matched 40,278 known genes. The reads, generated by the Illumina Genome Analyzer, were found to map to 31,284 contigs out of the 55,296 contigs serving as the database. A total of 8,353 contigs were found to exhibit differential expression between the two root types (at least 2.5-fold change). The Illumina-based differential expression results were validated for nine putative genes using quantitative real-time PCR. The differential expression profiles indicated down-regulation of classical root functions, such as transport, as well as down-regulation of lignin biosynthesis in initiating storage roots, and up-regulation of carbohydrate metabolism and starch biosynthesis. In addition, data indicated delicate control of regulators of meristematic tissue identity and maintenance, associated with the initiation of storage root formation. This study adds a valuable resource of sweetpotato root transcript sequences to available data, facilitating the identification of genes of interest. This resource enabled us to identify genes that are involved in the earliest stage of storage

  9. Transcriptional profiling of sweetpotato (Ipomoea batatas) roots indicates down-regulation of lignin biosynthesis and up-regulation of starch biosynthesis at an early stage of storage root formation

    Science.gov (United States)

    2013-01-01

    Background The number of fibrous roots that develop into storage roots determines sweetpotato yield. The aim of the present study was to identify the molecular mechanisms involved in the initiation of storage root formation, by performing a detailed transcriptomic analysis of initiating storage roots using next-generation sequencing platforms. A two-step approach was undertaken: (1) generating a database for the sweetpotato root transcriptome using 454-Roche sequencing of a cDNA library created from pooled samples of two root types: fibrous and initiating storage roots; (2) comparing the expression profiles of initiating storage roots and fibrous roots, using the Illumina Genome Analyzer to sequence cDNA libraries of the two root types and map the data onto the root transcriptome database. Results Use of the 454-Roche platform generated a total of 524,607 reads, 85.6% of which were clustered into 55,296 contigs that matched 40,278 known genes. The reads, generated by the Illumina Genome Analyzer, were found to map to 31,284 contigs out of the 55,296 contigs serving as the database. A total of 8,353 contigs were found to exhibit differential expression between the two root types (at least 2.5-fold change). The Illumina-based differential expression results were validated for nine putative genes using quantitative real-time PCR. The differential expression profiles indicated down-regulation of classical root functions, such as transport, as well as down-regulation of lignin biosynthesis in initiating storage roots, and up-regulation of carbohydrate metabolism and starch biosynthesis. In addition, data indicated delicate control of regulators of meristematic tissue identity and maintenance, associated with the initiation of storage root formation. Conclusions This study adds a valuable resource of sweetpotato root transcript sequences to available data, facilitating the identification of genes of interest. This resource enabled us to identify genes that are involved

  10. Metabolomic analysis and phenylpropanoid biosynthesis in hairy root culture of tartary buckwheat cultivars.

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    Aye Aye Thwe

    Full Text Available Buckwheat, Fagopyrum tataricum Gaertn., is an important medicinal plant, which contains several phenolic compounds, including one of the highest content of rutin, a phenolic compound with anti-inflammatory properties. An experiment was conducted to investigate the level of expression of various genes in the phenylpropanoid biosynthetic pathway to analyze in vitro production of anthocyanin and phenolic compounds from hairy root cultures derived from 2 cultivars of tartary buckwheat (Hokkai T8 and T10. A total of 47 metabolites were identified by gas chromatography-time-of-flight mass spectrometry (GC-TOFMS and subjected to principal component analysis (PCA in order to fully distinguish between Hokkai T8 and T10 hairy roots. The expression levels of phenylpropanoid biosynthetic pathway genes, through qRT-PCR, showed higher expression for almost all the genes in T10 than T8 hairy root except for FtF3'H-2 and FtFLS-2. Rutin, quercetin, gallic acid, caffeic acid, ferulic acid, 4-hydroxybenzoic acid, and 2 anthocyanin compounds were identified in Hokkai T8 and T10 hairy roots. The concentration of rutin and anthocyanin in Hokkai T10 hairy roots of tartary buckwheat was several-fold higher compared with that obtained from Hokkai T8 hairy root. This study provides useful information on the molecular and physiological dynamic processes that are correlated with phenylpropanoid biosynthetic gene expression and phenolic compound content in F. tataricum species.

  11. Effects of auxins on sorgoleone accumulation and genes for sorgoleone biosynthesis in sorghum roots.

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    Uddin, Md Romij; Park, Woo Tae; Kim, Yong Kyoung; Pyon, Jong Yeong; Park, Sang-Un

    2011-12-28

    Sorgoleone is a major component of the hydrophobic root exudate of Sorghum bicolor and is of particular interest to plant chemical ecology as well as agriculture. Sorgoleone was evaluated in this study to observe the expression levels of genes involved in its biosynthesis in response to auxins. Sorgoleone content varied widely according to the duration of application and the concentrations of the auxins. When the application time was increased, the sorgoleone content increased accordingly for all concentrations of IBA (1, 3, and 5 mg/L) and at 1 mg/L for both IAA and NAA. In this study, five different sorgoleone biosynthetic genes were observed, namely DES2, DES3, ARS1, ARS2, and OMT3, which are upregulated in response to IAA, IBA, and NAA. Transcript accumulation was apparent for all genes, but particularly for DES2, which increased up to 475-fold and 180-fold following 72 h exposure to NAA and IBA, respectively, compared to no treatment.

  12. Histochemical screening, metabolite profiling and expression analysis reveal Rosaceae roots as the site of flavan-3-ol biosynthesis.

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    Hoffmann, T; Friedlhuber, R; Steinhauser, C; Tittel, I; Skowranek, K; Schwab, W; Fischer, T C

    2012-01-01

    Histochemical screening of 30 Rosaceae genera representing all classic subfamilies demonstrated flavan-3-ols (catechins) as general secondary metabolites in roots of Rosaceae. Semi-quantitative LC-MS analyses confirmed the presence of catechin, epicatechin and various dimeric flavan-3-ols (also representing higher polymeric proanthocyanidins) as prominent polyphenols in root tips of Fragaria (strawberry), Malus (apple), Rosa (rose), Pyrus (pear) and Prunus (plum). Distinct patterns of flavan-3-ol distribution at the cellular level were found in strawberry (Fragaria × ananassa) and apple (Malus × domestica) root tips. The calyptras (root caps) showed the most prominent flavan-3-ol staining for these two genera. Border cells of Fragaria and Malus, as first demonstrated here for Rosaceae, were also found to contain flavan-3-ols. Transcript analyses with cDNA demonstrated root expression of known flavonoid genes expressed in the respective fruits and leaves. Primarily, this proves in situ biosynthesis of flavan-3-ols in these roots. Knowledge of the distinct cellular distribution patterns and their in situ biosynthesis in roots provides a basis for analysis of the functional roles of Rosaceae root flavan-3-ols. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Natural variation in expression of genes associated with carotenoid biosynthesis and accumulation in cassava (Manihot esculenta Crantz) storage root.

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    Carvalho, Luiz Jcb; Agustini, Marco Av; Anderson, James V; Vieira, Eduardo A; de Souza, Claudia Rb; Chen, Songbi; Schaal, Barbara A; Silva, Joseane P

    2016-06-10

    Cassava (Manihot esculenta Crantz) storage root provides a staple food source for millions of people worldwide. Increasing the carotenoid content in storage root of cassava could provide improved nutritional and health benefits. Because carotenoid accumulation has been associated with storage root color, this study characterized carotenoid profiles, and abundance of key transcripts associated with carotenoid biosynthesis, from 23 landraces of cassava storage root ranging in color from white-to-yellow-to-pink. This study provides important information to plant breeding programs aimed at improving cassava storage root nutritional quality. Among the 23 landraces, five carotenoid types were detected in storage root with white color, while carotenoid types ranged from 1 to 21 in storage root with pink and yellow color. The majority of storage root in these landraces ranged in color from pale-to-intense yellow. In this color group, total β-carotene, containing all-E-, 9-Z-, and 13-Z-β-carotene isomers, was the major carotenoid type detected, varying from 26.13 to 76.72 %. Although no α-carotene was observed, variable amounts of a α-ring derived xanthophyll, lutein, was detected; with greater accumulation of α-ring xanthophylls than of β-ring xanthophyll. Lycopene was detected in a landrace (Cas51) with pink color storage root, but it was not detected in storage root with yellow color. Based on microarray and qRT-PCR analyses, abundance of transcripts coding for enzymes involved in carotenoid biosynthesis were consistent with carotenoid composition determined by contrasting HPLC-Diode Array profiles from storage root of landraces IAC12, Cas64, and Cas51. Abundance of transcripts encoding for proteins regulating plastid division were also consistent with the observed differences in total β-carotene accumulation. Among the 23 cassava landraces with varying storage root color and diverse carotenoid types and profiles, landrace Cas51 (pink color storage root) had low

  14. Spiroacetal biosynthesis in fruit flies is complex: distinguishable origins of the same major spiroacetal released by different Bactrocera spp.

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    Schwartz, Brett D; Booth, Yvonne K; Fletcher, Mary T; Kitching, William; De Voss, James J

    2010-03-07

    The major spiroacetal ((E,E)-1) of the pestiferous fruit flies, Bactrocera tryoni and Bactrocera cucumis, is biosynthesised from fatty acids by distinguishable pathways which utilise modified beta-oxidation and C-H hydroxylation, generating a putative ketodiol which cyclises.

  15. Silencing the Transcriptional Repressor, ZCT1, Illustrates the Tight Regulation of Terpenoid Indole Alkaloid Biosynthesis in Catharanthus roseus Hairy Roots.

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    Noreen F Rizvi

    Full Text Available The Catharanthus roseus plant is the source of many valuable terpenoid indole alkaloids (TIAs, including the anticancer compounds vinblastine and vincristine. Transcription factors (TFs are promising metabolic engineering targets due to their ability to regulate multiple biosynthetic pathway genes. To increase TIA biosynthesis, we elicited the TIA transcriptional activators (ORCAs and other unidentified TFs with the plant hormone, methyl jasmonate (MJ, while simultaneously silencing the expression of the transcriptional repressor ZCT1. To silence ZCT1, we developed transgenic hairy root cultures of C. roseus that expressed an estrogen-inducible Zct1 hairpin for activating RNA interference. The presence of 17β-estradiol (5μM effectively depleted Zct1 in hairy root cultures elicited with MJ dosages that either optimize or inhibit TIA production (250 or 1000μM. However, silencing Zct1 was not sufficient to increase TIA production or the expression of the TIA biosynthetic genes (G10h, Tdc, and Str, illustrating the tight regulation of TIA biosynthesis. The repression of the TIA biosynthetic genes at the inhibitory MJ dosage does not appear to be solely regulated by ZCT1. For instance, while Zct1 and Zct2 levels decreased through activating the Zct1 hairpin, Zct3 levels remained elevated. Since ZCT repressors have redundant yet distinct functions, silencing all three ZCTs may be necessary to relieve their repression of alkaloid biosynthesis.

  16. Drought stress provokes the down-regulation of methionine and ethylene biosynthesis pathways in Medicago truncatula roots and nodules.

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    Larrainzar, Estíbaliz; Molenaar, Johanna A; Wienkoop, Stefanie; Gil-Quintana, Erena; Alibert, Bénédicte; Limami, Anis M; Arrese-Igor, Cesar; González, Esther M

    2014-09-01

    Symbiotic nitrogen fixation is one of the first physiological processes inhibited in legume plants under water-deficit conditions. Despite the progress made in the last decades, the molecular mechanisms behind this regulation are not fully understood yet. Recent proteomic work carried out in the model legume Medicago truncatula provided the first indications of a possible involvement of nodule methionine (Met) biosynthesis and related pathways in response to water-deficit conditions. To better understand this involvement, the drought-induced changes in expression and content of enzymes involved in the biosynthesis of Met, S-adenosyl-L-methionine (SAM) and ethylene in M. truncatula root and nodules were analyzed using targeted approaches. Nitrogen-fixing plants were subjected to a progressive water deficit and a subsequent recovery period. Besides the physiological characterization of the plants, the content of total sulphur, sulphate and main S-containing metabolites was measured. Results presented here show that S availability is not a limiting factor in the drought-induced decline of nitrogen fixation rates in M. truncatula plants and provide evidences for a down-regulation of the Met and ethylene biosynthesis pathways in roots and nodules in response to water-deficit conditions. © 2014 John Wiley & Sons Ltd.

  17. Transcriptome analysis reveals in vitro cultured Withania somnifera leaf and root tissues as a promising source for targeted withanolide biosynthesis.

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    Senthil, Kalaiselvi; Jayakodi, Murukarthick; Thirugnanasambantham, Pankajavalli; Lee, Sang Choon; Duraisamy, Pradeepa; Purushotham, Preethi M; Rajasekaran, Kalaiselvi; Nancy Charles, Shobana; Mariam Roy, Irene; Nagappan, Arul Kumar; Kim, Gon Sup; Lee, Yun Sun; Natesan, Senthil; Min, Tae-Sun; Yang, Tae Jin

    2015-01-22

    The production of metabolites via in vitro culture is promoted by the availability of fully defined metabolic pathways. Withanolides, the major bioactive phytochemicals of Withania somnifera, have been well studied for their pharmacological activities. However, only a few attempts have been made to identify key candidate genes involved in withanolide biosynthesis. Understanding the steps involved in withanolide biosynthesis is essential for metabolic engineering of this plant to increase withanolide production. Transcriptome sequencing was performed on in vitro adventitious root and leaf tissues using the Illumina platform. We obtained a total of 177,156 assembled transcripts with an average unigene length of 1,033 bp. About 13% of the transcripts were unique to in vitro adventitious roots but no unique transcripts were observed in in vitro-grown leaves. A putative withanolide biosynthetic pathway was deduced by mapping the assembled transcripts to the KEGG database, and the expression of candidate withanolide biosynthesis genes -were validated by qRT PCR. The accumulation pattern of withaferin A and withanolide A varied according to the type of tissue and the culture period. Further, we demonstrated that in vitro leaf extracts exhibit anticancer activity against human gastric adenocarcinoma cell lines at sub G1 phase. We report here a validated large-scale transcriptome data set and the potential biological activity of in vitro cultures of W. somnifera. This study provides important information to enhance tissue-specific expression and accumulation of secondary metabolites, paving the way for industrialization of in vitro cultures of W. somnifera.

  18. Polyamine biosynthesis and degradation are modulated by exogenous gamma-aminobutyric acid in root-zone hypoxia-stressed melon roots.

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    Wang, Chunyan; Fan, Longquan; Gao, Hongbo; Wu, Xiaolei; Li, Jingrui; Lv, Guiyun; Gong, Binbin

    2014-09-01

    We detected physiological change and gene expression related to PA metabolism in melon roots under controlled and hypoxic conditions with or without 5 mM GABA. Roots with hypoxia treatment showed a significant increase in glutamate decarboxylase (GAD) activity and endogenous GABA concentration. Concurrently, PA biosynthesis and degradation accelerated with higher gene expression and enzymes activity. However, endogenous GABA concentrations showed a large and rapid increase in Hypoxia + GABA treated roots. This led to a marked increase in Glu concentration by feedback inhibition of GAD activity. Hypoxia + GABA treatment enhanced arginine (Arg), ornithine (Orn) and methionine (Met) levels, promoting enzyme gene expression levels and arginine decarboxylase (ADC), ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) activities in roots. Hypoxia + GABA treatment significantly increased concentrations of free putrescine (Put), spermidine (Spd) and spermine (Spm) from day two to eight, promoting the PA conversion to soluble conjugated and insoluble bound forms. However, PA degradation was significantly inhibited in hypoxia + GABA treated roots by significantly decreasing gene expression and activity of diamine oxidase (DAO) and polyamine oxidase (PAO). However, exogenous GABA showed a reduced effect in control compared with hypoxic conditions. Our data suggest that alleviating effect of exogenous GABA to hypoxia is closely associated with physiological regulation of PA metabolism. We propose a potential negative feedback mechanism of higher endogenous GABA levels from combined effects of hypoxia and exogenous GABA, which alleviate the hypoxia damage by accelerating PA biosynthesis and conversion as well as preventing PA degradation in melon plants. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  19. RNA-Seq mediated root transcriptome analysis of Chlorophytum borivilianum for identification of genes involved in saponin biosynthesis.

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    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.

  20. Arabidopsis NITRILASE 1 Contributes to the Regulation of Root Growth and Development through Modulation of Auxin Biosynthesis in Seedlings.

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    Lehmann, Thomas; Janowitz, Tim; Sánchez-Parra, Beatriz; Alonso, Marta-Marina Pérez; Trompetter, Inga; Piotrowski, Markus; Pollmann, Stephan

    2017-01-01

    Nitrilases consist of a group of enzymes that catalyze the hydrolysis of organic cyanides. They are found ubiquitously distributed in the plant kingdom. Plant nitrilases are mainly involved in the detoxification of ß-cyanoalanine, a side-product of ethylene biosynthesis. In the model plant Arabidopsis thaliana a second group of Brassicaceae -specific nitrilases (NIT1-3) has been found. This so-called NIT1-subfamily has been associated with the conversion of indole-3-acetonitrile (IAN) into the major plant growth hormone, indole-3-acetic acid (IAA). However, apart of reported functions in defense responses to pathogens and in responses to sulfur depletion, conclusive insight into the general physiological function of the NIT-subfamily nitrilases remains elusive. In this report, we test both the contribution of the indole-3-acetaldoxime (IAOx) pathway to general auxin biosynthesis and the influence of altered nitrilase expression on plant development. Apart of a comprehensive transcriptomics approach to explore the role of the IAOx route in auxin formation, we took a genetic approach to disclose the function of NITRILASE 1 (NIT1) of A. thaliana . We show that NIT1 over-expression (NIT1ox) results in seedlings with shorter primary roots, and an increased number of lateral roots. In addition, NIT1ox plants exhibit drastic changes of both free IAA and IAN levels, which are suggested to be the reason for the observed phenotype. On the other hand, NIT2 RNAi knockdown lines, capable of suppressing the expression of all members of the NIT1-subfamily, were generated and characterized to substantiate the above-mentioned findings. Our results demonstrate for the first time that Arabidopsis NIT1 has profound effects on root morphogenesis in early seedling development.

  1. THE USE OF INTER SIMPLE SEQUENCE REPEATS (ISSR) IN DISTINGUISHING NEIGHBORING DOUGLAS-FIR TREES AS A MEANS TO IDENTIFYING TREE ROOTS WITH ABOVE-GROUND BIOMASS

    Science.gov (United States)

    We are attempting to identify specific root fragments from soil cores with individual trees. We successfully used Inter Simple Sequence Repeats (ISSR) to distinguish neighboring old-growth Douglas-fir trees from one another, while maintaining identity among each tree's parts. W...

  2. Enhanced root growth in phosphate-starved Arabidopsis by stimulating de novo phospholipid biosynthesis through the overexpression of LYSOPHOSPHATIDIC ACID ACYLTRANSFERASE 2 (LPAT2).

    Science.gov (United States)

    Angkawijaya, Artik Elisa; Nguyen, Van Cam; Nakamura, Yuki

    2017-09-01

    Upon phosphate starvation, plants retard shoot growth but promote root development presumably to enhance phosphate assimilation from the ground. Membrane lipid remodelling is a metabolic adaptation that replaces membrane phospholipids by non-phosphorous galactolipids, thereby allowing plants to obtain scarce phosphate yet maintain the membrane structure. However, stoichiometry of this phospholipid-to-galactolipid conversion may not account for the massive demand of membrane lipids that enables active growth of roots under phosphate starvation, thereby suggesting the involvement of de novo phospholipid biosynthesis, which is not represented in the current model. We overexpressed an endoplasmic reticulum-localized lysophosphatidic acid acyltransferase, LPAT2, a key enzyme that catalyses the last step of de novo phospholipid biosynthesis. Two independent LPAT2 overexpression lines showed no visible phenotype under normal conditions but showed increased root length under phosphate starvation, with no effect on phosphate starvation response including marker gene expression, root hair development and anthocyanin accumulation. Accompanying membrane glycerolipid profiling of LPAT2-overexpressing plants revealed an increased content of major phospholipid classes and distinct responses to phosphate starvation between shoot and root. The findings propose a revised model of membrane lipid remodelling, in which de novo phospholipid biosynthesis mediated by LPAT2 contributes significantly to root development under phosphate starvation. © 2017 John Wiley & Sons Ltd.

  3. Glucosinolate biosynthesis in hairy root cultures of broccoli (Brassica oleracea var. italica).

    Science.gov (United States)

    Kim, Sun-Ju; Park, Woo Tae; Uddin, Md Romij; Kim, Yeon Bok; Nam, Sang-Yong; Jho, Kwang Hyun; Park, Sang Un

    2013-02-01

    Here we present previously unreported glucosinolate production by hairy root cultures of broccoli (B. oleracea var. italica). Growth media greatly influenced the growth and glucosinolate content of hairy root cultures of broccoli. Seven glucosinolates, glucoraphanin, gluconapin, glucoerucin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin, were identified by analysis of the broccoli hairy root cultures. Both half and full strength B5 and SH media enabled the highest accumulation of glucosinolates. In most cases, the levels of glucosinolates were higher in SH and BS media. Among the 7 glucosinolates, the accumulation of neoglucobrassicin was very high, irrespective of growth medium. The neoglucobrassicin content was 7.4-fold higher in SH medium than 1/2 MS, in which its level was the lowest. The 1/2 B5 medium supported the production of the highest amounts of glucobrassicin and 4-methoxyglucobrassicin, the levels for which were 36.2- and 7.9- fold higher, respectively, than their lowest content in 1/2 MS medium. The 1/2 SH medium enabled the highest accumulation of glucoraphanin and gluconapin in the broccoli hairy root cultures, whose levels were 1.8- and 4.6-fold higher, respectively, than their lowest content in 1/2 MS medium. Our results suggest that hairy root cultures of broccoli could be a valuable alternative approach for the production of glucosinolate compounds.

  4. Biosynthesis of coumarin glycosides by transgenic hairy roots of Polygonum multiflorum.

    Science.gov (United States)

    Zhou, Liangbin; Tian, Tian; Xue, Bailin; Song, Liyan; Liu, Ling; Yu, Rongmin

    2012-01-01

    To investigate the substrate specificity and regio-selectivity of coumarin glycosyltransferases in transgenic hairy roots of Polygonum multiflorum, esculetin (1) and eight hydroxycoumarins (2-9) were employed as substrates. Nine corresponding glycosides (10-18) involving four new compounds, 6-chloro-4-methylcoumarin 7-O-β-D-glucopyranoside (15), 6-chloro-4-phenylcoumarin 7-O-β-D-glucopyranoside (16), 8-hydroxy-4-methylcoumarin 7-O-β-D-glucopyranoside (17), and 8-allyl-4-methylcoumarin 7-O-β-D-glucopyranoside (18), were biosynthesized by the hairy roots.

  5. Coronin from roots of Annona muricata, a putative intermediate in acetogenin biosynthesis (1).

    Science.gov (United States)

    Gleye, C; Akendengue, B; Laurens, A; Hocquemiller, R

    2001-08-01

    A novel acetogenin, coronin, was isolated from the roots of Annona muricata L. The structure was elucidated by a combination of chemical and spectral methods including MS and NMR measurements. Coronin is probably an intermediate in the biosynthetic pathway of bis-tetrahydrofuran acetogenins, and is proposed as a biogenetic precursor of neoannonin-B.

  6. Revealing complexity and specificity in the activation of lipase-mediated oxylipin biosynthesis: a specific role of the Nicotiana attenuata GLA1 lipase in the activation of jasmonic acid biosynthesis in leaves and roots.

    Science.gov (United States)

    Bonaventure, Gustavo; Schuck, Stefan; Baldwin, Ian T

    2011-09-01

    The activation of enzymatic oxylipin biosynthesis upon wounding, herbivory and pathogen attack depends on the biochemical activation of lipases that make polyunsaturated fatty acids (PUFAs) available to lipoxygenases (LOXs). The identity and number of the lipases involved in this process remain controversial and they probably differ among plant species. Analysis of transgenic Nicotiana attenuata plants (ir-gla1) stably reduced in the expression of the NaGLA1 gene showed that this plastidial glycerolipase is a major supplier of trienoic fatty acids for jasmonic acid (JA) biosynthesis in leaves and roots after wounding and simulated herbivory, but not during infection with the oomycete Phytophthora parasitica (var. nicotianae). NaGLA1 was not essential for the developmental control of JA biosynthesis in flowers and for the biosynthesis of C(6) volatiles by the hydroperoxide lyase (HPL) pathway; however, it affected the metabolism of divinyl ethers (DVEs) early during infection with P. parasitica (var. nicotianae) and the accumulation of NaDES1 and NaLOX1 mRNAs. Profiling of lysolipids by LC-MS/MS was consistent with a rapid activation of NaGLA1 and indicated that this lipase utilizes different lipid classes as substrates. The results revealed the complexity and specificity of the regulation of lipase-mediated oxylipin biosynthesis, highlighting the existence of pathway- and stimulus-specific lipases. © 2011 Blackwell Publishing Ltd.

  7. Acetic acid acts as an elicitor exerting a chitosan-like effect on xanthone biosynthesis in Hypericum perforatum L. root cultures.

    Science.gov (United States)

    Valletta, Alessio; De Angelis, Giulia; Badiali, Camilla; Brasili, Elisa; Miccheli, Alfredo; Di Cocco, Maria Enrica; Pasqua, Gabriella

    2016-05-01

    Acetic acid acts as a signal molecule, strongly enhancing xanthone biosynthesis in Hypericum perforatum root cultures. This activity is specific, as demonstrated by the comparison with other short-chain monocarboxylic acids. We have recently demonstrated that Hypericum perforatum root cultures constitutively produce xanthones at higher levels than the root of the plant and that they respond to chitosan (CHIT) elicitation with a noteworthy increase in xanthone production. In the present study, CHIT was administered to H. perforatum root cultures using three different elicitation protocols, and the increase in xanthone production was evaluated. The best results (550 % xanthone increase) were obtained by subjecting the roots to a single elicitation with 200 mg l(-1) CHIT and maintaining the elicitor in the culture medium for 7 days. To discriminate the effect of CHIT from that of the solvent, control experiments were performed by administering AcOH alone at the same concentration used for CHIT solubilization. Unexpectedly, AcOH caused an increase in xanthone production comparable to that observed in response to CHIT. Feeding experiments with (13)C-labeled AcOH demonstrated that this compound was not incorporated into the xanthone skeleton. Other short-chain monocarboxylic acids (i.e., propionic and butyric acid) have little or no effect on the production of xanthones. These results indicate that AcOH acts as a specific signal molecule, able to greatly enhance xanthone biosynthesis in H. perforatum root cultures.

  8. Common and distinguishing features of the bacterial and fungal communities in biological soil crusts and shrub root zone soils

    Science.gov (United States)

    Steven, Blaire; Gallegos-Graves, La Verne; Yeager, Chris; Belnap, Jayne; Kuske, Cheryl R.

    2013-01-01

    Soil microbial communities in dryland ecosystems play important roles as root associates of the widely spaced plants and as the dominant members of biological soil crusts (biocrusts) colonizing the plant interspaces. We employed rRNA gene sequencing (bacterial 16S/fungal large subunit) and shotgun metagenomic sequencing to compare the microbial communities inhabiting the root zones of the dominant shrub, Larrea tridentata (creosote bush), and the interspace biocrusts in a Mojave desert shrubland within the Nevada Free Air CO2 Enrichment (FACE) experiment. Most of the numerically abundant bacteria and fungi were present in both the biocrusts and root zones, although the proportional abundance of those members differed significantly between habitats. Biocrust bacteria were predominantly Cyanobacteria while root zones harbored significantly more Actinobacteria and Proteobacteria. Pezizomycetes fungi dominated the biocrusts while Dothideomycetes were highest in root zones. Functional gene abundances in metagenome sequence datasets reflected the taxonomic differences noted in the 16S rRNA datasets. For example, functional categories related to photosynthesis, circadian clock proteins, and heterocyst-associated genes were enriched in the biocrusts, where populations of Cyanobacteria were larger. Genes related to potassium metabolism were also more abundant in the biocrusts, suggesting differences in nutrient cycling between biocrusts and root zones. Finally, ten years of elevated atmospheric CO2 did not result in large shifts in taxonomic composition of the bacterial or fungal communities or the functional gene inventories in the shotgun metagenomes.

  9. Biosynthesis, characterization and antimicrobial action of silver nanoparticles from root bark extract of Berberislycium Royle.

    Science.gov (United States)

    Mehmood, Ansar; Murtaza, Ghulam; Bhatti, Tariq Mahmood; Kausar, Rehana; Ahmed, Muhammad Jamil

    2016-01-01

    Various biological methods are being recognized for the fabrication of silver nanoparticles, which are used in several fields. The phytosynthesis of nanoparticles came out as a cost effective and enviro-friendly approach. When root bark extract of Berberis lycium was treated with silver ions, they reduced to silver nanoparticles, which were spherical, crystalline, size ranged from 10-100nm and capped by biomolecules. Synthesized silver nanoparticles were characterized by UV-visible spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD) and Fourier Transform Infra Red Spectroscopy (FTIR). The plant mediated synthesized silver nanoparticles showed pronounced antimicrobial activities against both Gram negative bacteria (Escherichia coli, Klebseilla pneumoniae, Pseudomonas aeruginosa) and Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis). The plant mediated process proved to be non-toxic and low cost contender as reducing agent for synthesizing stable silver nanoparticles.

  10. Strictosidine-related enzymes involved in the alkaloid biosynthesis of Uncaria tomentosa root cultures grown under oxidative stress.

    Science.gov (United States)

    Vera-Reyes, Ileana; Huerta-Heredia, Ariana A; Ponce-Noyola, Teresa; Flores-Sanchez, Isvett Josefina; Esparza-García, Fernando; Cerda-García-Rojas, Carlos M; Trejo-Tapia, Gabriela; Ramos-Valdivia, Ana C

    2013-01-01

    The activity and gene expression of strictosidine-related enzymes in Uncaria tomentosa root cultures exposed to oxidative stress were studied. Elicitation with 0.2 mM hydrogen peroxide (H2 O2 ) or a combination of 0.8 mM buthionine sulfoximine and 0.2 mM jasmonic acid (BSO-JA) increased peroxidase activities by twofold at Day 8 and glutathione reductase by 1.4-fold at Day 5 in H2 O2 elicited cultures respect to the control. Production of monoterpenoid oxindole alkaloids (MOA), 3α-dihydrocadambine, and dolichantoside was stimulated after H2 O2 elicitation, reaching levels of 886.4 ± 23.6, 847.7 ± 25.4, and 87.5 ± 7.2 µg/g DW, at Day 8 which were 1.7-, 2.1-, and 2.3-fold higher relative to control. BSO-JA elicited cultures produced about twice alkaloids than H2 O2 -treated cultures, following a biphasic pattern with maxima at 0.5 and 8 days. Alkaloid production was preceded by increase in strictosidine synthase (STR) and strictosidine glucosidase (SGD) activities. After elicitation with H2 O2 or BSO-JA, the STR activity (pKat/mg protein) increased by 1.9-fold (93.8 ± 17.8 at 24 h) or 2.5-fold (102.4 ± 2.2 at 6 h) and the SGD activity (pKat/mg protein) by 2.8-fold (245.2 ± 14.4 at 6 h) or 4.2-fold (421.2 ± 1.8 at 18 h) relative to control. STR and SGD transcripts were upregulated after elicitation. H2 O2 -treated roots showed higher levels of STR at 48-192 h and SGD at 24-48 h, while BSO-JA treatments showed STR increased at 12 h and SGD at 24 h. Also, LC/ESI-MS confirmed the biosynthesis of dolichantoside from N-ω-methyltryptamine and secologanin by U. tomentosa protein extracts. © 2013 American Institute of Chemical Engineers.

  11. De Novo Assembly, Functional Annotation and Comparative Analysis of Withania somnifera Leaf and Root Transcriptomes to Identify Putative Genes Involved in the Withanolides Biosynthesis

    Science.gov (United States)

    Gupta, Parul; Goel, Ridhi; Pathak, Sumya; Srivastava, Apeksha; Singh, Surya Pratap; Sangwan, Rajender Singh; Asif, Mehar Hasan; Trivedi, Prabodh Kumar

    2013-01-01

    Withania somnifera is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicine systems due to bioactive molecules known as withanolides. As genomic information regarding this plant is very limited, little information is available about biosynthesis of withanolides. To facilitate the basic understanding about the withanolide biosynthesis pathways, we performed transcriptome sequencing for Withania leaf (101L) and root (101R) which specifically synthesize withaferin A and withanolide A, respectively. Pyrosequencing yielded 8,34,068 and 7,21,755 reads which got assembled into 89,548 and 1,14,814 unique sequences from 101L and 101R, respectively. A total of 47,885 (101L) and 54,123 (101R) could be annotated using TAIR10, NR, tomato and potato databases. Gene Ontology and KEGG analyses provided a detailed view of all the enzymes involved in withanolide backbone synthesis. Our analysis identified members of cytochrome P450, glycosyltransferase and methyltransferase gene families with unique presence or differential expression in leaf and root and might be involved in synthesis of tissue-specific withanolides. We also detected simple sequence repeats (SSRs) in transcriptome data for use in future genetic studies. Comprehensive sequence resource developed for Withania, in this study, will help to elucidate biosynthetic pathway for tissue-specific synthesis of secondary plant products in non-model plant organisms as well as will be helpful in developing strategies for enhanced biosynthesis of withanolides through biotechnological approaches. PMID:23667511

  12. De novo assembly, functional annotation and comparative analysis of Withania somnifera leaf and root transcriptomes to identify putative genes involved in the withanolides biosynthesis.

    Directory of Open Access Journals (Sweden)

    Parul Gupta

    Full Text Available Withania somnifera is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicine systems due to bioactive molecules known as withanolides. As genomic information regarding this plant is very limited, little information is available about biosynthesis of withanolides. To facilitate the basic understanding about the withanolide biosynthesis pathways, we performed transcriptome sequencing for Withania leaf (101L and root (101R which specifically synthesize withaferin A and withanolide A, respectively. Pyrosequencing yielded 8,34,068 and 7,21,755 reads which got assembled into 89,548 and 1,14,814 unique sequences from 101L and 101R, respectively. A total of 47,885 (101L and 54,123 (101R could be annotated using TAIR10, NR, tomato and potato databases. Gene Ontology and KEGG analyses provided a detailed view of all the enzymes involved in withanolide backbone synthesis. Our analysis identified members of cytochrome P450, glycosyltransferase and methyltransferase gene families with unique presence or differential expression in leaf and root and might be involved in synthesis of tissue-specific withanolides. We also detected simple sequence repeats (SSRs in transcriptome data for use in future genetic studies. Comprehensive sequence resource developed for Withania, in this study, will help to elucidate biosynthetic pathway for tissue-specific synthesis of secondary plant products in non-model plant organisms as well as will be helpful in developing strategies for enhanced biosynthesis of withanolides through biotechnological approaches.

  13. Transcriptome Analysis of Salicylic Acid Treatment in Rehmannia glutinosa Hairy Roots Using RNA-seq Technique for Identification of Genes Involved in Acteoside Biosynthesis

    Directory of Open Access Journals (Sweden)

    Fengqing Wang

    2017-05-01

    Full Text Available Rehmannia glutinosa is a common bulk medicinal material that has been widely used in China due to its active ingredients. Acteoside, one of the ingredients, has antioxidant, antinephritic, anti-inflammatory, hepatoprotective, immunomodulatory, and neuroprotective effects, is usually selected as a quality-control component for R. glutinosa herb in the Chinese Pharmacopeia. The acteoside biosynthesis pathway in R. glutinosa has not yet been clearly established. Herein, we describe the establishment of a genetic transformation system for R. glutinosa mediated by Agrobacterium rhizogenes. We screened the optimal elicitors that markedly increased acteoside accumulation in R. glutinosa hairy roots. We found that acteoside accumulation dramatically increased with the addition of salicylic acid (SA; the optimal SA dose was 25 μmol/L for hairy roots. RNA-seq was applied to analyze the transcriptomic changes in hairy roots treated with SA for 24 h in comparison with an untreated control. A total of 3,716, 4,018, and 2,715 differentially expressed transcripts (DETs were identified in 0 h-vs.-12 h, 0 h-vs.-24 h, and 12 h-vs.-24 h libraries, respectively. KEGG pathway-based analysis revealed that 127 DETs were enriched in “phenylpropanoid biosynthesis.” Of 219 putative unigenes involved in acteoside biosynthesis, 54 were found to be up-regulated at at least one of the time points after SA treatment. Selected candidate genes were analyzed by quantitative real-time PCR (qRT-PCR in hairy roots with SA, methyl jasmonate (MeJA, AgNO3 (Ag+, and putrescine (Put treatment. All genes investigated were up-regulated by SA treatment, and most candidate genes were weakly increased by MeJA to some degree. Furthermore, transcription abundance of eight candidate genes in tuberous roots of the high-acteoside-content (HA cultivar QH were higher than those of the low-acteoside-content (LA cultivar Wen 85-5. These results will pave the way for understanding the molecular

  14. The rice OsNAC6 transcription factor orchestrates multiple molecular mechanisms involving root structural adaptions and nicotianamine biosynthesis for drought tolerance.

    Science.gov (United States)

    Lee, Dong-Keun; Chung, Pil Joong; Jeong, Jin Seo; Jang, Geupil; Bang, Seung Woon; Jung, Harin; Kim, Youn Shic; Ha, Sun-Hwa; Choi, Yang Do; Kim, Ju-Kon

    2017-06-01

    Drought has a serious impact on agriculture worldwide. A plant's ability to adapt to rhizosphere drought stress requires reprogramming of root growth and development. Although physiological studies have documented the root adaption for tolerance to the drought stress, underlying molecular mechanisms is still incomplete, which is essential for crop engineering. Here, we identified OsNAC6-mediated root structural adaptations, including increased root number and root diameter, which enhanced drought tolerance. Multiyear drought field tests demonstrated that the grain yield of OsNAC6 root-specific overexpressing transgenic rice lines was less affected by drought stress than were nontransgenic controls. Genome-wide analyses of loss- and gain-of-function mutants revealed that OsNAC6 up-regulates the expression of direct target genes involved in membrane modification, nicotianamine (NA) biosynthesis, glutathione relocation, 3'-phophoadenosine 5'-phosphosulphate accumulation and glycosylation, which represent multiple drought tolerance pathways. Moreover, overexpression of NICOTIANAMINE SYNTHASE genes, direct targets of OsNAC6, promoted the accumulation of the metal chelator NA and, consequently, drought tolerance. Collectively, OsNAC6 orchestrates novel molecular drought tolerance mechanisms and has potential for the biotechnological development of high-yielding crops under water-limiting conditions. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  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. PMID:28293252

  16. 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.

  17. RNAi inhibition of feruloyl CoA 6'-hydroxylase reduces scopoletin biosynthesis and post-harvest physiological deterioration in cassava (Manihot esculenta Crantz) storage roots.

    Science.gov (United States)

    Liu, Shi; Zainuddin, Ima M; Vanderschuren, Herve; Doughty, James; Beeching, John R

    2017-05-01

    Cassava (Manihot esculenta Crantz) is a major world crop, whose storage roots provide food for over 800 million throughout the humid tropics. Despite many advantages as a crop, the development of cassava is seriously constrained by the rapid post-harvest physiological deterioration (PPD) of its roots that occurs within 24-72 h of harvest, rendering the roots unpalatable and unmarketable. PPD limits cassava's marketing possibilities in countries that are undergoing increased development and urbanisation due to growing distances between farms and consumers. The inevitable wounding of the roots caused by harvesting triggers an oxidative burst that spreads throughout the cassava root, together with the accumulation of secondary metabolites including phenolic compounds, of which the coumarin scopoletin (7-hydroxy-6-methoxy-2H-1-benzopyran-2-one) is the most abundant. Scopoletin oxidation yields a blue-black colour, which suggests its involvement in the discoloration observed during PPD. Feruloyl CoA 6'-hydroxylase is a controlling enzyme in the biosynthesis of scopoletin. The cassava genome contains a seven membered family of feruloyl CoA 6'-hydroxylase genes, four of which are expressed in the storage root and, of these, three were capable of functionally complementing Arabidopsis T-DNA insertion mutants in this gene. A RNA interference construct, designed to a highly conserved region of these genes, was used to transform cassava, where it significantly reduced feruloyl CoA 6'-hydroxylase gene expression, scopoletin accumulation and PPD symptom development. Collectively, our results provide evidence that scopoletin plays a major functional role in the development of PPD symptoms, rather than merely paralleling symptom development in the cassava storage root.

  18. Biosynthesis of Germacrene A Carboxylic Acid in Chicory Roots. Demonstration of a Cytochrome P450 (+)-Germacrene A Hydroxylase and NADP+-Dependent Sesquiterpenoid Dehydrogenase(s) Involved in Sesquiterpene Lactone Biosynthesis

    Science.gov (United States)

    de Kraker, Jan-Willem; Franssen, Maurice C. R.; Dalm, Marcella C. F.; de Groot, Aede; Bouwmeester, Harro J.

    2001-01-01

    Sprouts of chicory (Cichorium intybus), a vegetable grown in the dark, have a slightly bitter taste associated with the presence of guaianolides, eudesmanolides, and germacranolides. The committed step in the biosynthesis of these compounds is catalyzed by a (+)-germacrene A synthase. Formation of the lactone ring is the postulated next step in biosynthesis of the germacrene-derived sesquiterpene lactones. The present study confirms this hypothesis by isolation of enzyme activities from chicory roots that introduce a carboxylic acid function in the germacrene A isopropenyl side chain, which is necessary for lactone ring formation. (+)-Germacrene A is hydroxylated to germacra-1(10),4,11(13)-trien-12-ol by a cytochrome P450 enzyme, and is subsequently oxidized to germacra-1(10),4,11(13)-trien-12-oic acid by NADP+-dependent dehydrogenase(s). Both oxidized germacrenes were detected as their Cope-rearrangement products elema-1,3,11(13)-trien-12-ol and elema-1,3,11(13)-trien-12-oic acid, respectively. The cyclization products of germacra-1(10),4,11(13)-trien-12-ol, i.e. costol, were also observed. The (+)-germacrene A hydroxylase is inhibited by carbon monoxide (blue-light reversible), has an optimum pH at 8.0, and hydroxylates β-elemene with a modest degree of enantioselectivity. PMID:11299372

  19. Proliferation and ajmalicine biosynthesis of Catharanthus roseus (L). G. Don adventitious roots in self-built temporary immersion system

    Science.gov (United States)

    Phuc, Vo Thanh; Trung, Nguyen Minh; Thien, Huynh Tri; Tien, Le Thi Thuy

    2017-09-01

    Periwinkle (Catharanthus roseus (L.) G. Don) is a medicinal plant containing about 130 types of alkaloids that have important pharmacological effects. Ajmalicine in periwinkle root is an antihypertensive drug used in treatment of high blood pressure. Adventitious roots obtained from periwinkle leaves of in vitro shoots grew well in quarter-strength MS medium supplemented with 0.3 mg/l IBA and 20 g/l sucrose. Dark condition was more suitable for root growth than light. However, callus formation also took place in addition to the growth of adventitious roots. Temporary immersion system was applied in the culture of adventitious roots in order to reduce the callus growth rate formed in shake flask cultures. The highest growth index of roots was achieved using the system with 5-min immersion every 45 min (1.676 ± 0.041). The roots cultured in this system grew well without callus formation. Ajmalicine content was highest in the roots cultured with 5-min immersion every 180 min (950 μg/g dry weight).

  20. Mutations in Arabidopsis thaliana genes involved in the tryptophan biosynthesis pathway affect root waving on tilted agar surfaces

    Science.gov (United States)

    Rutherford, R.; Gallois, P.; Masson, P. H.

    1998-01-01

    Arabidopsis thaliana roots grow in a wavy pattern upon a slanted surface. A novel mutation in the anthranilate synthase alpha 1 (ASA1) gene, named trp5-2wvc1, and mutations in the tryptophan synthase alpha and beta 1 genes (trp3-1 and trp2-1, respectively) confer a compressed root wave phenotype on tilted agar surfaces. When trp5-2wvc1 seedlings are grown on media supplemented with anthranilate metabolites, their roots wave like wild type. Genetic and pharmacological experiments argue that the compressed root wave phenotypes of trp5-2wvc1, trp2-1 and trp3-1 seedlings are not due to reduced IAA biosynthetic potential, but rather to a deficiency in L-tryptophan (L-Trp), or in a L-Trp derivative. Although the roots of 7-day-old seedlings possess higher concentrations of free L-Trp than the shoot as a whole, trp5-2wvc1 mutants show no detectable alteration in L-Trp levels in either tissue type, suggesting that a very localized shortage of L-Trp, or of a L-Trp-derived compound, is responsible for the observed phenotype.

  1. Osmotic stress represses strigolactone biosynthesis in Lotus japonicus roots: exploring the interaction between strigolactones and ABA under abiotic stress

    KAUST Repository

    Liu, Junwei

    2015-02-26

    Main conclusion: Strigolactone changes and cross talk with ABA unveil a picture of root-specific hormonal dynamics under stress.Abstract: Strigolactones (SLs) are carotenoid-derived hormones influencing diverse aspects of development and communication with (micro)organisms, and proposed as mediators of environmental stimuli in resource allocation processes; to contribute to adaptive adjustments, therefore, their pathway must be responsive to environmental cues. To investigate the relationship between SLs and abiotic stress in Lotus japonicus, we compared wild-type and SL-depleted plants, and studied SL metabolism in roots stressed osmotically and/or phosphate starved. SL-depleted plants showed increased stomatal conductance, both under normal and stress conditions, and impaired resistance to drought associated with slower stomatal closure in response to abscisic acid (ABA). This confirms that SLs contribute to drought resistance in species other than Arabidopsis. However, we also observed that osmotic stress rapidly and strongly decreased SL concentration in tissues and exudates of wild-type Lotus roots, by acting on the transcription of biosynthetic and transporter-encoding genes and independently of phosphate abundance. Pre-treatment with exogenous SLs inhibited the osmotic stress-induced ABA increase in wild-type roots and down-regulated the transcription of the ABA biosynthetic gene LjNCED2. We propose that a transcriptionally regulated, early SL decrease under osmotic stress is needed (but not sufficient) to allow the physiological increase of ABA in roots. This work shows that SL metabolism and effects on ABA are seemingly opposite in roots and shoots under stress.

  2. Large expression differences in genes for iron and zinc homeostasis, stress response, and lignin biosynthesis distinguish roots of Arabidopsis thaliana and the related metal hyperaccumulator Thlaspi caerulescens

    NARCIS (Netherlands)

    van de Mortel, Judith E.; Almar Villanueva, Laia; Schat, Henk; Kwekkeboom, Jeroen; Coughlan, Sean; Moerland, Perry D.; Ver Loren van Themaat, Emiel; Koornneef, Maarten; Aarts, Mark G. M.

    2006-01-01

    The micronutrient zinc has an essential role in physiological and metabolic processes in plants as a cofactor or structural element in 300 catalytic and noncatalytic proteins, but it is very toxic when available in elevated amounts. Plants tightly regulate their internal zinc concentrations in a

  3. Large Expression Differences in Genes for Iron and Zinc Homeostasis, Stress Response, and Lignin Biosynthesis Distinguish Roots of Arabidopsis thaliana and the Related Metal Hyperaccumulator Thlaspi caerulescens.

    NARCIS (Netherlands)

    Mortel, van de J.E.; Almar Villanueva, L.; Schat, H.; Kwekkeboom, J.; Coughlan, S.; Moerland, P.D.; Verloren van Themaat, E.; Koornneef, M.; Aarts, M.G.M.

    2006-01-01

    The micronutrient zinc has an essential role in physiological and metabolic processes in plants as a cofactor or structural element in 300 catalytic and noncatalytic proteins, but it is very toxic when available in elevated amounts. Plants tightly regulate their internal zinc concentrations in a

  4. The development of a green approach for the biosynthesis of silver and gold nanoparticles by using Panax ginseng root extract, and their biological applications.

    Science.gov (United States)

    Singh, Priyanka; Kim, Yeon Ju; Wang, Chao; Mathiyalagan, Ramya; Yang, Deok Chun

    2016-06-01

    The biosynthesis of nanoparticles has received attention because of the development of economic and environmentally friendly technology for the synthesis of nanoparticles. The study develops a convenient method for the green synthesis of silver and gold nanoparticles by utilizing fresh root extract of the four-year old Panax ginseng plant, and evaluated the antimicrobial applications of silver nanoparticles against pathogenic microorganisms. P. ginseng is a well-known herbal medicinal plant, and its active ingredients are mainly ginsenosides. The fresh root of the 4 year old P. ginseng plant has been explored for the synthesis of silver and gold nanoparticles without the use of any additional reducing and capping agents. The reduction of silver nitrate led to the formation of silver nanoparticles within 2 h of reaction at 80°C. The gold nanoparticles were also successfully synthesized by the reduction of auric acid at 80°C, within 5 min of reaction. The biosynthesized gold and silver nanoparticles were characterized by techniques using various instruments, viz. ultraviolet-visible spectroscopy (UV-Vis spectroscopy), field emission transmission electron microscopy (FE-TEM), energy dispersive X-ray analysis (EDX), elemental mapping, and X-ray diffraction (XRD). In addition, the silver nanoparticles have shown antimicrobial potential against Bacillus anthracis, Vibrio parahaemolyticus, Staphylococcus aureus, Escherichia coli, and Bacillus cereus.

  5. Non-ribosomal Peptide Synthases from Pseudomonas aeruginosa Play a Role in Cyclodipeptide Biosynthesis, Quorum-Sensing Regulation, and Root Development in a Plant Host.

    Science.gov (United States)

    González, Omar; Ortíz-Castro, Randy; Díaz-Pérez, César; Díaz-Pérez, Alma L; Magaña-Dueñas, Viridiana; López-Bucio, José; Campos-García, Jesús

    2017-04-01

    Diverse molecules mediate cross-kingdom communication between bacteria and their eukaryotic partners and determine pathogenic or symbiotic relationships. N-acyl-L-homoserine lactone-dependent quorum-sensing signaling represses the biosynthesis of bacterial cyclodipeptides (CDPs) that act as auxin signal mimics in the host plant Arabidopsis thaliana. In this work, we performed bioinformatics, biochemical, and plant growth analyses to identify non-ribosomal peptide synthase (NRPS) proteins of Pseudomonas aeruginosa, which are involved in CDP synthesis. A reverse genetics strategy allowed the identification of the genes encoding putative multi-modular-NRPS (MM-NRPS). Mutations in these genes affected the synthesis of the CDPs cyclo(L-Pro-L-Val), cyclo(L-Pro-L-Leu), and cyclo(L-Pro-L-Tyr), while showing wild-type-like levels of virulence factors, such as violacein, elastase, and pyocyanin. When analyzing the bioactivity of purified, naturally produced CDPs, it was found that cyclo(L-Pro-L-Tyr) and cyclo(L-Pro-L-Val) were capable of antagonizing quorum-sensing-LasR (QS-LasR)-dependent signaling in a contrasting manner in the cell-free supernatants of the selected NRPS mutants, which showed QS induction. Using a bacteria-plant interaction system, we further show that the pvdJ, ambB, and pchE P. aeruginosa mutants failed to repress primary root growth, but improved root branching in A. thaliana seedlings. These results indicated that the CDP production in P. aeruginosa depended on the functional MM-NRPS, which influences quorum-sensing of bacteria and plays a role in root architecture remodeling.

  6. Improvement of biosynthesis and accumulation of bioactive compounds by elicitation in adventitious root cultures of Polygonum multiflorum.

    Science.gov (United States)

    Ho, Thanh-Tam; Lee, Jong-Du; Jeong, Cheol-Seung; Paek, Kee-Yoeup; Park, So-Young

    2018-01-01

    We examined the effects of abiotic (methyl jasmonate [MeJA] and salicylic acid [SA]) and biotic (yeast extract and chitosan) elicitors for improvement of bioactive compounds production on adventitious root cultures in Polygonum multiflorum. The application of yeast extract resulted in significantly (p ≤ 0.05) higher dry root biomass (9.98 g/L) and relative growth rate versus the control. Cultures treated with abiotic elicitors showed higher percentage of dry weight than the other samples. Low concentrations of all elicitors (50 μM MeJA and SA, and 50 mg/L yeast extract) improved secondary metabolite production except for chitosan, whose performance was worse than that of the control. HPLC analysis of various bioactive compounds revealed significantly higher elicitation efficiency for MeJA than for the other treatments, with an approximately 2-fold increase in root dry weight (22.08 mg/g DW) under 50 μM MeJA treatment versus the control (10.35 mg/g DW). We also investigated the feasibility of scaling up the production process by comparing shake flask cultures with 3- and 5-L balloon type bubble bioreactors (BTBB) using 50 μM MeJA as an elicitor. Growth and metabolite accumulation increased in BTBB compared with shake flask cultures. We detected a non-significant difference in biomass productivity between 3 and 5-L BTBB, but the efficiency of bioactive compound accumulation decreased with increasing volume. These findings will be useful for developing a pilot-scale P. multiflorum adventitious root cultivation process for high biomass and bioactive compound production to meet the demands for natural ingredients by the pharmaceutical and cosmetic industries without affecting the natural habitat of this plant.

  7. Disruption of dTDP-rhamnose biosynthesis modifies lipopolysaccharide core, exopolysaccharide production, and root colonization in Azospirillum brasilense.

    Science.gov (United States)

    Jofré, Edgardo; Lagares, Antonio; Mori, Gladys

    2004-02-16

    The interaction between Azospirillum brasilense and plants is not fully understood, although several bacterial surface components like exopolysaccharides (EPS), flagella, and capsular polysaccharides are required for attachment and colonization. While in other plant-bacteria associations (Rhizobium-legume, Pseudomonas-potato), lipopolysaccharides (LPS) play a key role in the establishment of an effective association, their role in the root colonization by Azospirillum had not been determined. In this study, we isolated a Tn5 mutant of A. brasilense Cd (EJ1) with an apparently modified LPS core structure, non-mucoid colony morphology, increased EPS production, and affected in maize root colonization. A 3790-bp region revealed the presence of three complete open reading frames designated rmlC, rmlB and rmlD. The beginning of a fourth open reading frame was found and designated rmlA. These genes are organized in a cluster which shows homology to the cluster involved in the synthesis of dTDP-rhamnose in other bacteria. Additionally, the analysis of the monosaccharide composition of LPSs showed a diminution of rhamnose compared to the wild-type strain.

  8. Biosynthesis, Characterization, and Bioactivities Evaluation of Silver and Gold Nanoparticles Mediated by the Roots of Chinese Herbal Angelica pubescens Maxim

    Science.gov (United States)

    Markus, Josua; Wang, Dandan; Kim, Yeon-Ju; Ahn, Sungeun; Mathiyalagan, Ramya; Wang, Chao; Yang, Deok Chun

    2017-01-01

    A facile synthesis and biological applications of silver (DH-AgNps) and gold nanoparticles (DH-AuNps) mediated by the aqueous extract of Angelicae Pubescentis Radix (Du Huo) are explored. Du Huo is a medicinal root belonging to Angelica pubescens Maxim which possesses anti-inflammatory, analgesic, and antioxidant properties. The absorption spectra of nanoparticles in varying root extract and metal ion concentration, pH, reaction temperatures, and time were recorded by ultraviolet-visible (UV-Vis) spectroscopy. The presence of DH-AgNps and DH-AuNps was confirmed from the surface plasmon resonance intensified at 414 and 540 nm, respectively. Field emission transmission electron micrograph (FE-TEM) analysis revealed the formation of quasi-spherical DH-AgNps and spherical icosahedral DH-AuNps. These novel DH-AgNps and DH-AuNps maintained an average crystallite size of 12.48 and 7.44 nm, respectively. The biosynthesized DH-AgNps and DH-AuNps exhibited antioxidant activity against 2,2-diphenyl-1-picrylhydrzyl (DPPH) radicals and the former exhibited antimicrobial activity against clinical pathogens including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica. The expected presence of flavonoids, sesquiterpenes, and phenols on the nanoparticle surface were conjectured to grant protection against aggregation and free radical scavenging activity. DH-AgNps and DH-AuNps were further investigated for their cytotoxic properties in RAW264.7 macrophages for their potential application as drug carriers to sites of inflammation. In conclusion, this green synthesis is favorable for the advancement of plant mediated nano-carriers in drug delivery systems, cancer diagnostic, and medical imaging.

  9. Poly-β-hydroxybutyrate and exopolysaccharide biosynthesis by bacterial isolates from pigeonpea [Cajanus cajan (L.) Millsp] root nodules.

    Science.gov (United States)

    Fernandes, Paulo Ivan; de Oliveira, Paulo Jansen; Rumjanek, Norma Gouvêa; Xavier, Gustavo Ribeiro

    2011-02-01

    The bacterial strains that are able to produce biopolymers that are applied in industrial sectors present a source of renewable resources. Some microorganisms are already applied at several industrial sectors, but the prospecting of new microbes must bring microorganisms that are feasible to produce interesting biopolymers more efficiently and in cheaper conditions. Among the biopolymers applied industrially, polyhydroxybutyrate (PHB) and exopolysaccharides (EPS) stand out because of its applications, mainly in biodegradable plastic production and in food industry, respectively. In this context, the capacity of bacteria isolated from pigeonpea root nodules to produce EPS and PHB was evaluated, as well as the cultural characterization of these isolates. Among the 38 isolates evaluated, the majority presented fast growth and ability to acidify the culture media. Regarding the biopolymer production, five isolates produced more than 10 mg PHB per liter of culture medium. Six EPS producing bacteria achieved more than 200 mg EPS per liter of culture medium. Evaluating different carbon sources, the PHB productivity of the isolate 24.6b reached 69% of cell dry weight when cultured with starch as sole carbon source, and the isolate 8.1c synthesized 53% PHB in dry cell biomass and more than 1.3 g L⁻¹ of EPS when grown using xylose as sole carbon source.

  10. Biosynthesis of Germacrene A Carboxylic Acid in Chicory Roots. Demonstration of a Cytochrome P450 (+)-Germacrene A Hydroxylase and NADP+-Dependent Sesquiterpenoid Dehydrogenase(s) Involved in Sesquiterpene Lactone Biosynthesis

    NARCIS (Netherlands)

    Kraker, de J.W.; Franssen, M.C.R.; Dalm, M.C.F.; Groot, de Æ.; Bouwmeester, H.J.

    2001-01-01

    Sprouts of chicory (Cichorium intybus), a vegetable grown in the dark, have a slightly bitter taste associated with the presence of guaianolides, eudesmanolides, and germacranolides. The committed step in the biosynthesis of these compounds is catalyzed by a ( )-germacrene A synthase. Formation of

  11. Plant roots use a patterning mechanism to position lateral root branches toward available water.

    Science.gov (United States)

    Bao, Yun; Aggarwal, Pooja; Robbins, Neil E; Sturrock, Craig J; Thompson, Mark C; Tan, Han Qi; Tham, Cliff; Duan, Lina; Rodriguez, Pedro L; Vernoux, Teva; Mooney, Sacha J; Bennett, Malcolm J; Dinneny, José R

    2014-06-24

    The architecture of the branched root system of plants is a major determinant of vigor. Water availability is known to impact root physiology and growth; however, the spatial scale at which this stimulus influences root architecture is poorly understood. Here we reveal that differences in the availability of water across the circumferential axis of the root create spatial cues that determine the position of lateral root branches. We show that roots of several plant species can distinguish between a wet surface and air environments and that this also impacts the patterning of root hairs, anthocyanins, and aerenchyma in a phenomenon we describe as hydropatterning. This environmental response is distinct from a touch response and requires available water to induce lateral roots along a contacted surface. X-ray microscale computed tomography and 3D reconstruction of soil-grown root systems demonstrate that such responses also occur under physiologically relevant conditions. Using early-stage lateral root markers, we show that hydropatterning acts before the initiation stage and likely determines the circumferential position at which lateral root founder cells are specified. Hydropatterning is independent of endogenous abscisic acid signaling, distinguishing it from a classic water-stress response. Higher water availability induces the biosynthesis and transport of the lateral root-inductive signal auxin through local regulation of tryptophan aminotransferase of Arabidopsis 1 and PIN-formed 3, both of which are necessary for normal hydropatterning. Our work suggests that water availability is sensed and interpreted at the suborgan level and locally patterns a wide variety of developmental processes in the root.

  12. Differential effects of fenpropimorph and fenhexamid, two sterol biosynthesis inhibitor fungicides, on arbuscular mycorrhizal development and sterol metabolism in carrot roots.

    Science.gov (United States)

    Campagnac, Estelle; Fontaine, Joël; Sahraoui, Anissa Lounès-Hadj; Laruelle, Frédéric; Durand, Roger; Grandmougin-Ferjani, Anne

    2008-12-01

    Sterols composition of transformed carrot roots incubated in presence of increasing concentrations of fenpropimorph (0.02; 0.2; 2mgl(-1)) and fenhexamid (0.02; 0.2; 2; 20mgl(-1)), colonized or not by Glomus intraradices was determined. In mycorrhizal roots treated with fenpropimorph, normal Delta(5)-sterols were replaced by unusual compounds such as 9beta,19-cyclopropylsterols (24-methylpollinastanol), Delta(8,14)-sterols (ergosta-8,14-dienol, stigmasta-8,14-dienol), Delta(8)-sterols (Delta(8) sitosterol) and Delta(7)-sterols (ergosta-7,22-dienol). After application of fenpropimorph, a drastic reduction of the mycorrhizal root growth, root colonization and extraradical fungal development was observed. Application of fenhexamid did not modify sterol profiles and the total colonization of roots. But the arbuscule frequency of the fungal partner was significantly affected. Comparison of the effects caused by the tested fungicides indicates that the usual phytosterols may be involved in symbiosis development. Indeed, observed modifications of root sterols composition could explain the high fenpropimorph toxicity to the AM symbiosis. However, the absence of sterolic modifications in the roots treated with fenhexamid could account for its more limited impact on mycorrhization.

  13. Stimulation of artemisinin biosynthesis in Artemisia annua hairy ...

    African Journals Online (AJOL)

    , the OGA-induced reactive oxygen species (ROS) were involved in stimulating the artemisinin biosynthesis in the hairy roots. This is the first report on the stimulation of artemisinin production in hairy roots by an oligogalacturonide elicitor.

  14. Expression of important pathway genes involved in withanolides biosynthesis in hairy root culture of Withania somnifera upon treatment with Gracilaria edulis and Sargassum wightii.

    Science.gov (United States)

    Sivanandhan, Ganeshan; Arunachalam, Chinnathambi; Selvaraj, Natesan; Sulaiman, Ali Alharbi; Lim, Yong Pyo; Ganapathi, Andy

    2015-06-01

    The investigation of seaweeds, Gracilaria edulis and Sargassum wightii extracts was carried out for the estimation of growth characteristics and major withanolides production in hairy root culture of Withania somnifera. The extract of G. edulis (50%) in MS liquid basal medium enabled maximum production of dry biomass (5.46 g DW) and withanolides contents (withanolide A 5.23 mg/g DW; withaferin A 2.24 mg/g DW and withanone 4.83 mg/g DW) in hairy roots after 40 days of culture with 48 h contact time. The obtained withanolides contents were significantly higher (2.32-fold-2.66-fold) in hairy root culture when compared to the control. RT PCR analysis of important pathway genes such as SE, SS, HMGR and FPPS exhibited substantial higher expression upon the seaweed extracts treatment in hairy root culture. This experiment would paw a platform for withanolides production in hairy root culture with the influence of sea weed extracts for pharmaceutical companies in the future. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. (+)-Germacrene A Biosynthesis

    Science.gov (United States)

    de Kraker, Jan-Willem; Franssen, Maurice C.R.; de Groot, Aede; König, Wilfried A.; Bouwmeester, Harro J.

    1998-01-01

    The leaves and especially the roots of chicory (Cichorium intybus L.) contain high concentrations of bitter sesquiterpene lactones such as the guianolides lactupicrin, lactucin, and 8-deoxylactucin. Eudesmanolides and germacranolides are present in smaller amounts. Their postulated biosynthesis through the mevalonate-farnesyl diphosphate-germacradiene pathway has now been confirmed by the isolation of a (+)-germacrene A synthase from chicory roots. This sesquiterpene cyclase was purified 200-fold using a combination of anion-exchange and dye-ligand chromatography. It has a Km value of 6.6 μm, an estimated molecular mass of 54 kD, and a (broad) pH optimum around 6.7. Germacrene A, the enzymatic product, proved to be much more stable than reported in literature. Its heat-induced Cope rearrangement into (−)-β-elemene was utilized to determine its absolute configuration on an enantioselective gas chromatography column. To our knowledge, until now in sesquiterpene biosynthesis, germacrene A has only been reported as an (postulated) enzyme-bound intermediate, which, instead of being released, is subjected to additional cyclization(s) by the same enzyme that generated it from farnesyl diphosphate. However, in chicory germacrene A is released from the sesquiterpene cyclase. Apparently, subsequent oxidations and/or glucosylation of the germacrane skeleton, together with a germacrene cyclase, determine whether guaiane- or eudesmane-type sesquiterpene lactones are produced. PMID:9701594

  16. Transcriptomic analysis of oxylipin biosynthesis genes and chemical profiling reveal an early induction of jasmonates in chickpea roots under drought stress.

    Science.gov (United States)

    De Domenico, Stefania; Bonsegna, Stefania; Horres, Ralf; Pastor, Victoria; Taurino, Marco; Poltronieri, Palmiro; Imtiaz, Muhammad; Kahl, Gunter; Flors, Victor; Winter, Peter; Santino, Angelo

    2012-12-01

    Drought is one of the major constraints in subtropical agriculture. Therefore improving water stress tolerance is of great importance to breed for drought tolerance in future. The first plant organ sensing dehydration is the root. Aim of the present work was to clarify the potential impact of the phyto-oxylipins pathway on drought tolerance of chickpea (Cicer arietinum), the third important legume crop worldwide. Therefore, we measured the expression of key genes involved in oxylipins metabolism by qPCR on samples from stressed and non-stressed roots of a drought-tolerant and a drought-sensitive chickpea variety using commercially available TaqMan assays. We demonstrate that the drought tolerant variety reacts to drought with sustained and earlier activation of a specific lipoxygenase (Mt-LOX 1) gene, two hydroperoxide lyases (Mt-HPL 1 and Mt-HPL 2), an allene oxide synthase (Mt-AOS), and an oxo-phytodienoate reductase (Mt-OPR). We further show that gene over-expression positively correlates with the levels of major oxylipin metabolites from the AOS branch of the pathway, which finally leads to the synthesis of jasmonates. Higher levels of jasmonic acid (JA), its precursor 12-oxophytodienoic acid (OPDA) and the active form JA-isoleucine (JA-Ile) were especially detected in the root tissues of the tolerant variety, prompting us to assume a role of jasmonates in the early signalling of drought stress in chickpea and its involvement in the tolerance mechanism of the drought-tolerant variety. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. Envisaging the Regulation of Alkaloid Biosynthesis and Associated Growth Kinetics in Hairy Roots of Vinca minor Through the Function of Artificial Neural Network.

    Science.gov (United States)

    Verma, Priyanka; Anjum, Shahin; Khan, Shamshad Ahmad; Roy, Sudeep; Odstrcilik, Jan; Mathur, Ajay Kumar

    2016-03-01

    Artificial neural network based modeling is a generic approach to understand and correlate different complex parameters of biological systems for improving the desired output. In addition, some new inferences can also be predicted in a shorter time with less cost and labor. As terpenoid indole alkaloid pathway in Vinca minor is very less investigated or elucidated, a strategy of elicitation with hydroxylase and acetyltransferase along with incorporation of various precursors from primary shikimate and secoiridoid pools via simultaneous employment of cyclooxygenase inhibitor was performed in the hairy roots of V. minor. This led to the increment in biomass accumulation, total alkaloid concentration, and vincamine production in selected treatments. The resultant experimental values were correlated with algorithm approaches of artificial neural network that assisted in finding the yield of vincamine, alkaloids, and growth kinetics using number of elicits. The inputs were the hydroxylase/acetyltransferase elicitors and cyclooxygenase inhibitor along with various precursors from shikimate and secoiridoid pools and the outputs were growth index (GI), alkaloids, and vincamine. The approach incorporates two MATLAB codes; GRNN and FFBPNN. Growth kinetic studies revealed that shikimate and tryptophan supplementation triggers biomass accumulation (GI = 440.2 to 540.5); while maximum alkaloid (3.7 % dry wt.) and vincamine production (0.017 ± 0.001 % dry wt.) was obtained on supplementation of secologanin along with tryptophan, naproxen, hydrogen peroxide, and acetic anhydride. The study shows that experimental and predicted values strongly correlate each other. The correlation coefficient for growth index (GI), alkaloids, and vincamine was found to be 0.9997, 0.9980, 0.9511 in GRNN and 0.9725, 0.9444, 0.9422 in FFBPNN, respectively. GRNN provided greater similarity between the target and predicted dataset in comparison to FFBPNN. The findings can provide future

  18. Arabinogalactan biosynthesis

    DEFF Research Database (Denmark)

    Poulsen, Christian Peter; Dilokpimol, Adiphol; Geshi, Naomi

    2015-01-01

    Arabinogalactan proteins are abundant cell surface proteoglycans in plants and are implicated to act as developmental markers during plant growth. We previously reported that AtGALT31A, AtGALT29A, and AtGLCAT14A-C, which are involved in the biosynthesis of arabinogalactan proteins, localize......GALT29A. Therefore, the electrostatic status of Y144, which is regulated by an unknown kinase/phosphatase system, may regulate AtGALT29A enzyme activity. Moreover, we have identified additional proteins, apyrase 3 (APY3; At1g14240) and UDPglucuronate epimerases 1 and 6 (GAE1, At4g30440; GAE6, At3g23820...

  19. Abscisic Acid Regulates Auxin Homeostasis in Rice Root Tips to Promote Root Hair Elongation

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2017-06-01

    Full Text Available Abscisic acid (ABA plays an essential role in root hair elongation in plants, but the regulatory mechanism remains to be elucidated. In this study, we found that exogenous ABA can promote rice root hair elongation. Transgenic rice overexpressing SAPK10 (Stress/ABA-activated protein kinase 10 had longer root hairs; rice plants overexpressing OsABIL2 (OsABI-Like 2 had attenuated ABA signaling and shorter root hairs, suggesting that the effect of ABA on root hair elongation depends on the conserved PYR/PP2C/SnRK2 ABA signaling module. Treatment of the DR5-GUS and OsPIN-GUS lines with ABA and an auxin efflux inhibitor showed that ABA-induced root hair elongation depends on polar auxin transport. To examine the transcriptional response to ABA, we divided rice root tips into three regions: short root hair, long root hair and root tip zones; and conducted RNA-seq analysis with or without ABA treatment. Examination of genes involved in auxin transport, biosynthesis and metabolism indicated that ABA promotes auxin biosynthesis and polar auxin transport in the root tip, which may lead to auxin accumulation in the long root hair zone. Our findings shed light on how ABA regulates root hair elongation through crosstalk with auxin biosynthesis and transport to orchestrate plant development.

  20. Root rots

    Science.gov (United States)

    Kathryn Robbins; Philip M. Wargo

    1989-01-01

    Root rots of central hardwoods are diseases caused by fungi that infect and decay woody roots and sometimes also invade the butt portion of the tree. By killing and decaying roots, root rotting fungi reduce growth, decrease tree vigor, and cause windthrow and death. The most common root diseases of central hardwoods are Armillaria root rot, lnonotus root rot, and...

  1. Combinatorial Biosynthesis – Potential and Problems

    Science.gov (United States)

    Floss, Heinz G.

    2007-01-01

    Because of their ecological functions, natural products have been optimized in evolution for interaction with biological systems and receptors. However, they have not necessarily been optimized for other desirable drug properties and thus can often be improved by structural modification. Using examples from the literature, this paper reviews the opportunities for increasing structural diversity among natural products by combinatorial biosynthesis, i.e., the genetic manipulation of biosynthetic pathways. It distinguishes between combinatorial biosynthesis in a narrower sense to generate libraries of modified structures, and metabolic engineering for the targeted formation of specific structural analogs. Some of the problems and limitations encountered with these approaches are also discussed. Work from the author’s laboratory on ansamycin antibiotics is presented which illustrates some of the opportunities and limitations. PMID:16414140

  2. A review on the molecular mechanism of plants rooting modulated ...

    African Journals Online (AJOL)

    Phytohormones, especially auxin, played an essential role in regulating roots developments. This review focused on recent advances in the research of plants rooting genomics and proteomics, including auxin biosynthesis, metabolism, transport, and signaling pathway which are involved in modulating plants rooting and ...

  3. Biosynthesis of tylophora alkaloids

    International Nuclear Information System (INIS)

    Mulchandani, N.B.; Iyer, S.S.; Badheka, L.P.

    1974-01-01

    Using labelled precursors, biosynthesis of the tylophora alkaloids, tylophorine, tylophorinidine and tylophorinide has been investigated in Tylophora asthmatica plants. The radioactive precursors, phenylalanine-2- 14 C, benzoic acid-1- 14 C, benzoic acid-ring 14 C, acetate-2- 14 C, ornithine-5- 14 C, acetate-2- 14 C, ornithine-5- 14 C and cinnamic acid-2- 14 C were administered to the plants individually by wick technique. Tylophorine was isolated in each case and assayed for its radioactivity to find out the incorporation of the label into it. The results indicate that: (1) phenylalanine via cinnamic acid is an important precursor in the biosynthesis of tylophorine (2) orinithine participates in tylophorine biosynthesis via pyrroline and (3) tylophorinidine may be a direct precursor of tylophorine. (M.G.B.)

  4. Aflatoxin biosynthesis: current frontiers.

    Science.gov (United States)

    Roze, Ludmila V; Hong, Sung-Yong; Linz, John E

    2013-01-01

    Aflatoxins are among the principal mycotoxins that contaminate economically important food and feed crops. Aflatoxin B1 is the most potent naturally occurring carcinogen known and is also an immunosuppressant. Occurrence of aflatoxins in crops has vast economic and human health impacts worldwide. Thus, the study of aflatoxin biosynthesis has become a focal point in attempts to reduce human exposure to aflatoxins. This review highlights recent advances in the field of aflatoxin biosynthesis and explores the functional connection between aflatoxin biosynthesis, endomembrane trafficking, and response to oxidative stress. Dissection of the regulatory mechanisms involves a complete comprehension of the aflatoxin biosynthetic process and the dynamic network of transcription factors that orchestrates coordinated expression of the target genes. Despite advancements in the field, development of a safe and effective multifaceted approach to solve the aflatoxin food contamination problem is still required.

  5. Ensemble Equivalence for Distinguishable Particles

    Directory of Open Access Journals (Sweden)

    Antonio Fernández-Peralta

    2016-07-01

    Full Text Available Statistics of distinguishable particles has become relevant in systems of colloidal particles and in the context of applications of statistical mechanics to complex networks. In this paper, we present evidence that a commonly used expression for the partition function of a system of distinguishable particles leads to huge fluctuations of the number of particles in the grand canonical ensemble and, consequently, to nonequivalence of statistical ensembles. We will show that the alternative definition of the partition function including, naturally, Boltzmann’s correct counting factor for distinguishable particles solves the problem and restores ensemble equivalence. Finally, we also show that this choice for the partition function does not produce any inconsistency for a system of distinguishable localized particles, where the monoparticular partition function is not extensive.

  6. Distinguishing drought and water scarcity

    NARCIS (Netherlands)

    Loon, van A.

    2013-01-01

    Water resources can become strained by both natural factors such as drought and human factors such as unsustainable use. Water resource managers can develop practices to reduce overuse of water resources, but they cannot prevent droughts, so distinguishing the causes of water stress can be useful.

  7. Root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed.......The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  8. Photomodulation of strigolactone biosynthesis and accumulation during sunflower seedling growth

    Science.gov (United States)

    Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander

    2015-01-01

    Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL – mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work. PMID:26252191

  9. [Optimization of oxytetracycline biosynthesis].

    Science.gov (United States)

    Maksimova, E A; Falkov, N N; Izmaĭlov, N N; Romanchuk, N N

    1988-06-01

    It was shown that rising of temperature up to 30 degrees C at the stage of the oxytetracycline-producing organism growth promoted acceleration of the culture growth rate and increasing of the antibiotic concentration by the 114th hour of the biosynthetic process. For the apparatus used in the study optimal aeration and agitation conditions were developed. To provide optimal parameters during biosynthesis of oxytetracycline, it was recommended to use the aeration rate of 1 v/v.min and the specific mechanical power for mixing of not less than 1 kW/m3.

  10. Biosynthesis of Rishirilide B

    Directory of Open Access Journals (Sweden)

    Philipp Schwarzer

    2018-03-01

    Full Text Available Rishirilide B was isolated from Streptomyces rishiriensis and Streptomyces bottropensis on the basis of its inhibitory activity towards alpha-2-macroglobulin. The biosynthesis of rishirilide B was investigated by feeding experiments with different 13C labelled precursors using the heterologous host Streptomyces albus J1074::cos4 containing a cosmid encoding of the gene cluster responsible for rishirilide B production. NMR spectroscopic analysis of labelled compounds demonstrate that the tricyclic backbone of rishirilide B is a polyketide synthesized from nine acetate units. One of the acetate units is decarboxylated to give a methyl group. The origin of the starter unit was determined to be isobutyrate.

  11. Root Hairs

    Science.gov (United States)

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  12. Distinguishing Ichthyoses by Protein Profiling

    Science.gov (United States)

    Rice, Robert H.; Bradshaw, Katie M.; Durbin-Johnson, Blythe P.; Rocke, David M.; Eigenheer, Richard A.; Phinney, Brett S.; Schmuth, Matthias; Gruber, Robert

    2013-01-01

    To explore the usefulness of protein profiling for characterization of ichthyoses, we here determined the profile of human epidermal stratum corneum by shotgun proteomics. Samples were analyzed after collection on tape circles from six anatomic sites (forearm, palm, lower leg, forehead, abdomen, upper back), demonstrating site-specific differences in profiles. Additional samples were collected from the forearms of subjects with ichthyosis vulgaris (filaggrin (FLG) deficiency), recessive X-linked ichthyosis (steroid sulfatase (STS) deficiency) and autosomal recessive congenital ichthyosis type lamellar ichthyosis (transglutaminase 1 (TGM1) deficiency). The ichthyosis protein expression patterns were readily distinguishable from each other and from phenotypically normal epidermis. In general, the degree of departure from normal was lower from ichthyosis vulgaris than from lamellar ichthyosis, parallel to the severity of the phenotype. Analysis of samples from families with ichthyosis vulgaris and concomitant modifying gene mutations (STS deficiency, GJB2 deficiency) permitted correlation of alterations in protein profile with more complex genetic constellations. PMID:24130705

  13. Root patterning

    NARCIS (Netherlands)

    Scheres, Ben; Laskowski, Marta

    2016-01-01

    The mechanisms that pattern lateral root primordial are essential for the elaboration of root system architecture, a trait of key importance for future crop breeding. But which are most important: periodic or local cues? In this issue of Journal of Experimental Botany (pages 1411-1420), Kircher

  14. Serine biosynthesis and transport defects.

    Science.gov (United States)

    El-Hattab, Ayman W

    2016-07-01

    l-serine is a non-essential amino acid that is biosynthesized via the enzymes phosphoglycerate dehydrogenase (PGDH), phosphoserine aminotransferase (PSAT), and phosphoserine phosphatase (PSP). Besides its role in protein synthesis, l-serine is a potent neurotrophic factor and a precursor of a number of essential compounds including phosphatidylserine, sphingomyelin, glycine, and d-serine. Serine biosynthesis defects result from impairments of PGDH, PSAT, or PSP leading to systemic serine deficiency. Serine biosynthesis defects present in a broad phenotypic spectrum that includes, at the severe end, Neu-Laxova syndrome, a lethal multiple congenital anomaly disease, intermediately, infantile serine biosynthesis defects with severe neurological manifestations and growth deficiency, and at the mild end, the childhood disease with intellectual disability. A serine transport defect resulting from deficiency of the ASCT1, the main transporter for serine in the central nervous system, has been recently described in children with neurological manifestations that overlap with those observed in serine biosynthesis defects. l-serine therapy may be beneficial in preventing or ameliorating symptoms in serine biosynthesis and transport defects, if started before neurological damage occurs. Herein, we review serine metabolism and transport, the clinical, biochemical, and molecular aspects of serine biosynthesis and transport defects, the mechanisms of these diseases, and the potential role of serine therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Carotenoid Biosynthesis in Fusarium

    Directory of Open Access Journals (Sweden)

    Javier Avalos

    2017-07-01

    Full Text Available Many fungi of the genus Fusarium stand out for the complexity of their secondary metabolism. Individual species may differ in their metabolic capacities, but they usually share the ability to synthesize carotenoids, a family of hydrophobic terpenoid pigments widely distributed in nature. Early studies on carotenoid biosynthesis in Fusarium aquaeductuum have been recently extended in Fusarium fujikuroi and Fusarium oxysporum, well-known biotechnological and phytopathogenic models, respectively. The major Fusarium carotenoid is neurosporaxanthin, a carboxylic xanthophyll synthesized from geranylgeranyl pyrophosphate through the activity of four enzymes, encoded by the genes carRA, carB, carT and carD. These fungi produce also minor amounts of β-carotene, which may be cleaved by the CarX oxygenase to produce retinal, the rhodopsin’s chromophore. The genes needed to produce retinal are organized in a gene cluster with a rhodopsin gene, while other carotenoid genes are not linked. In the investigated Fusarium species, the synthesis of carotenoids is induced by light through the transcriptional induction of the structural genes. In some species, deep-pigmented mutants with up-regulated expression of these genes are affected in the regulatory gene carS. The molecular mechanisms underlying the control by light and by the CarS protein are currently under investigation.

  16. Biosynthesis of Tetrahydroisoquinoline Antibiotics.

    Science.gov (United States)

    Tang, Gong-Li; Tang, Man-Cheng; Song, Li-Qiang; Zhang, Yue

    2016-01-01

    The tetrahydroisoquinoline (THIQ) alkaloids are naturally occurring antibiotics isolated from a variety of microorganisms and marine invertebrates. This family of natural products exhibit broad spectrum antimicrobial and strong antitumor activities, and the potency of clinical application has been validated by the marketing of ecteinascidin 743 (ET-743) as anticancer drug. In the past 20 years, the biosynthetic gene cluster of six THIQ antibiotics has been characterized including saframycin Mx1 from Myxococcus xanthus, safracin-B from Pseudomonas fluorescens, saframycin A, naphthyridinomycin, and quinocarcin from Streptomyces, as well as ET-743 from Ecteinascidia turbinata. This review gives a brief summary of the current status in understanding the molecular logic for the biosynthesis of these natural products, which provides new insights on the biosynthetic machinery involved in the nonribosomal peptide synthetase system. The proposal of the THIQ biosynthetic pathway not only shows nature's route to generate such complex molecules, but also set the stage to develop a different process for production of ET-743 by synthetic biology.

  17. Stereoselectivity in Polyphenol Biosynthesis

    Science.gov (United States)

    Lewis, Norman G.; Davin, Laurence B.

    1992-01-01

    Stereoselectivity plays an important role in the late stages of phenyl-propanoid metabolism, affording lignins, lignans, and neolignans. Stereoselectivity is manifested during monolignol (glucoside) synthesis, e.g., where the geometry (E or Z) of the pendant double bond affects the specificity of UDPG:coniferyl alcohol glucosyltransferases in different species. Such findings are viewed to have important ramifications in monolignol transport and storage processes, with roles for both E- and Z-monolignols and their glucosides in lignin/lignan biosynthesis being envisaged. Stereoselectivity is also of great importance in enantiose-lective enzymatic processes affording optically active lignans. Thus, cell-free extracts from Forsythia species were demonstrated to synthesize the enantiomerically pure lignans, (-)-secoisolariciresinol, and (-)-pinoresinol, when NAD(P)H, H2O2 and E-coniferyl alcohol were added. Progress toward elucidating the enzymatic steps involved in such highly stereoselective processes is discussed. Also described are preliminary studies aimed at developing methodologies to determine the subcellular location of late-stage phenylpropanoid metabolites (e.g., coniferyl alcohol) and key enzymes thereof, in intact tissue or cells. This knowledge is essential if questions regarding lignin and lignan tissue specificity and regulation of these processes are to be deciphered.

  18. Glycolipid biosynthesis in cyanobacteria

    International Nuclear Information System (INIS)

    Van Dusen, W.J.; Jaworski, J.G.

    1987-01-01

    The biosynthesis of monogalactosyldiacyl-glycerol (MGDG) was studied in five different cyanobacteria. Previous work has shown Anabaena variabilis to synthesize both MGDG and monoglucosyl-diacylglycerol (MG1cDG) with MG1cDG being the precursor of MGDG. They have examined four other cyanobacteria to determine if a similar relationship exists. The cyanobacteria studied were Anabaena variabilis, Chlorogloeopsis sp., Schizothrix calcicola, Anacystis nidulans, and Anacystis marina. Each were grown in liquid culture and lipids were labeled with 14 C]CO 2 for 20 min., 1.0 hr, 1.0 hr + 10 hr chase. Glycolipids were analyzed by initial separation of MGDG and MG1cDG by TLC followed by further analysis by HPLC. Complete separation of molecular species was obtained isocratically on an ODS column. All of the cyanobacteria labeled 16-C and 18-C fatty acids except for A. marina which labeled only 14-C and 16-C fatty acids. Desaturation of the fatty acids could be observed in the 1.0 hr and chase experiments. All were capable of labeling both MG1cDG and MGDG with the precursor-product relationship being observed. There does not appear to be a direct relationship between the epimerization of the sugar moiety and fatty acid desaturation

  19. Biosynthesis of silver nanoparticles.

    Science.gov (United States)

    Poulose, Subin; Panda, Tapobrata; Nair, Praseetha P; Théodore, Thomas

    2014-02-01

    Metal nanoparticles have unique optical, electronic, and catalytic properties. There exist well-defined physical and chemical processes for their preparation. Those processes often yield small quantities of nanoparticles having undesired morphology, and involve high temperatures for the reaction and the use of hazardous chemicals. Relatively, the older technique of bioremediation of metals uses either microorganisms or their components for the production of nanoparticles. The nanoparticles obtained from bacteria, fungi, algae, plants and their components, etc. appear environment-friendly, as toxic chemicals are not used in the processes. In addition to this, the formation of nanoparticles takes place at almost normal temperature and pressure. Control of the shape and size of the nanoparticles is possible by appropriate selection of the pH and temperature. Three important steps are the bioconversion of Ag+ ions, conversion of desired crystals to nanoparticles, and nanoparticle stability. Generally, nanoparticles are characterized by the UV-visible spectroscopy and use of the electron microscope. Silver nanoparticles are used as antimicrobial agents and they possess antifungal, anti-inflammatory, and anti-angiogenic properties. This review highlights the biosynthesis of silver nanoparticles by various organisms, possible mechanisms of their synthesis, their characterization, and applications of silver nanoparticles.

  20. Comparative transcriptome analysis of different chemotypes elucidates withanolide biosynthesis pathway from medicinal plant Withania somnifera.

    Science.gov (United States)

    Gupta, Parul; Goel, Ridhi; Agarwal, Aditya Vikram; Asif, Mehar Hasan; Sangwan, Neelam Singh; Sangwan, Rajender Singh; Trivedi, Prabodh Kumar

    2015-12-21

    Withania somnifera is one of the most valuable medicinal plants synthesizing secondary metabolites known as withanolides. Despite pharmaceutical importance, limited information is available about the biosynthesis of withanolides. Chemo-profiling of leaf and root tissues of Withania suggest differences in the content and/or nature of withanolides in different chemotypes. To identify genes involved in chemotype and/or tissue-specific withanolide biosynthesis, we established transcriptomes of leaf and root tissues of distinct chemotypes. Genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis with their alternatively spliced forms and paralogous have been identified. Analysis suggests differential expression of large number genes among leaf and root tissues of different chemotypes. Study also identified differentially expressing transcripts encoding cytochrome P450s, glycosyltransferases, methyltransferases and transcription factors which might be involved in chemodiversity in Withania. Virus induced gene silencing of the sterol ∆7-reductase (WsDWF5) involved in the synthesis of 24-methylene cholesterol, withanolide backbone, suggests role of this enzyme in biosynthesis of withanolides. Information generated, in this study, provides a rich resource for functional analysis of withanolide-specific genes to elucidate chemotype- as well as tissue-specific withanolide biosynthesis. This genomic resource will also help in development of new tools for functional genomics and breeding in Withania.

  1. Root resorption

    DEFF Research Database (Denmark)

    Kjaer, Inger

    2014-01-01

    Introduction: This paper summarizes the different conditions, which have a well-known influence on the resorption of tooth roots, exemplified by trauma and orthodontic treatment. The concept of the paper is to summarize and explain symptoms and signs of importance for avoiding resorption during...... orthodontic treatment. The Hypothesis: The hypothesis in this paper is that three different tissue layers covering the root in the so-called periroot sheet can explain signs and symptoms of importance for avoiding root resorption during orthodontic treatment. These different tissue layers are; outermost......-an ectodermal tissue layer (Malassez′s epithelium), a middle layer-composed by the collagen-mesodermal tissue layer, and an innermost root-close innervation layer. Abnormalities in one of these tissue layers are thought to cause inflammatory processes in the periodontal membrane comparable to inflammatory...

  2. Licorice Root

    Science.gov (United States)

    ... T U V W X Y Z Licorice Root Share: On This Page Background How Much Do ... This fact sheet provides basic information about licorice root—common names, usefulness and safety, and resources for ...

  3. A new method to optimize root order classification based on the diameter interval of fine root.

    Science.gov (United States)

    Liu, Ying; Wang, Guoliang; Yu, Kunxia; Li, Peng; Xiao, Lie; Liu, Guobin

    2018-02-13

    Plant roots are a highly heterogeneous and hierarchical system. Although the root-order method is superior to the root diameter method for revealing differences in the morphology and physiology of fine roots, its complex partitioning limits its application. Whether root order can be determined by partitioning the main root based on its diameter remains uncertain. Four methods were employed for studying the morphological characteristics of seedling roots of two Pinus species in a natural and nitrogen-enriched environment. The intrinsic relationships among categories of roots by root order and diameter were systematically compared to explore the possibility of using the latter to describe root morphology. The normal transformation method proved superior to the other three in that the diameter intervals corresponded most closely (at least 68.3%) to the morphological characteristics. The applied methods clearly distinguished the results from the natural and nitrogen-rich environments. Considering both root diameter and order simplified the classification of fine roots, and improved the estimation of root lifespan and the data integrity of field collection, but failed to partition all roots into uniform diameter intervals.

  4. Distinguished trajectories in time dependent vector fields

    OpenAIRE

    Madrid, J. A. Jimenez; Mancho, Ana M.

    2008-01-01

    We introduce a new definition of distinguished trajectory that generalizes the concepts of fixed point and periodic orbit to aperiodic dynamical systems. This new definition is valid for identifying distinguished trajectories with hyperbolic and nonhyperbolic types of stability. The definition is implemented numerically and the procedure consists of determining a path of limit coordinates. It has been successfully applied to known examples of distinguished trajectories. In the context of high...

  5. Expression of genes associated with carbohydrate metabolism in cotton stems and roots

    Directory of Open Access Journals (Sweden)

    Scheffler Jodi

    2009-01-01

    Full Text Available Abstract Background Cotton (Gossypium hirsutum L is an important crop worldwide that provides fiber for the textile industry. Cotton is a perennial plant that stores starch in stems and roots to provide carbohydrates for growth in subsequent seasons. Domesticated cotton makes these reserves available to developing seeds which impacts seed yield. The goals of these analyses were to identify genes and physiological pathways that establish cotton stems and roots as physiological sinks and investigate the role these pathways play in cotton development during seed set. Results Analysis of field-grown cotton plants indicated that starch levels peaked about the time of first anthesis and then declined similar to reports in greenhouse-grown cotton plants. Starch accumulated along the length of the stem and the shape and size of the starch grains from stems were easily distinguished from transient starch. Microarray analyses compared gene expression in tissues containing low levels of starch with tissues rapidly accumulating starch. Statistical analysis of differentially expressed genes indicated increased expression among genes associated with starch synthesis, starch degradation, hexose metabolism, raffinose synthesis and trehalose synthesis. The anticipated changes in these sugars were largely confirmed by measuring soluble sugars in selected tissues. Conclusion In domesticated cotton starch stored prior to flowering was available to support seed production. Starch accumulation observed in young field-grown plants was not observed in greenhouse grown plants. A suite of genes associated with starch biosynthesis was identified. The pathway for starch utilization after flowering was associated with an increase in expression of a glucan water dikinase gene as has been implicated in utilization of transient starch. Changes in raffinose levels and levels of expression of genes controlling trehalose and raffinose biosynthesis were also observed in vegetative

  6. Chlorogenic acid facilitates root hair formation in lettuce seedlings.

    Science.gov (United States)

    Narukawa, Megumi; Kanbara, Kaori; Tominaga, Yuji; Aitani, Yurika; Fukuda, Kazumasa; Kodama, Takaaki; Murayama, Noriko; Nara, Yoshiki; Arai, Takashi; Konno, Masae; Kamisuki, Shinji; Sugawara, Fumio; Iwai, Masako; Inoue, Yasunori

    2009-03-01

    Root hairs, which arise from root epidermal cells, are tubular structures that increase the efficiency of water absorption and nutrient uptake. A low pH (pH 4) medium induced root hair formation in lettuce (Lactuca sativa L.) seedlings, and the decapitation of shoots inhibited root hair formation. The addition of shoot extract to the medium restored root hair formation in the decapitated lettuce seedlings. These results suggest that factors essential to the formation of root hairs may be present in the shoot. We purified one factor from the shoot that facilitates root hair formation. This factor was identified as chlorogenic acid (CGA), a common polyphenol in higher plants. The presence of exogenous CGA in the medium induced root hair formation in decapitated lettuce seedlings at pH 4.0 and in intact lettuce seedlings at pH 6.0. The optimum concentration of CGA for root hair formation was identified as 10(-5) M. Decapitation of the shoots reduced the CGA content in the roots to approximately one-third that in intact plants. Application of the CGA biosynthesis inhibitor L-alpha-aminooxy-beta-phenylpropionic acid (AOPP, 10(-6) M) to intact seedlings grown at pH 4.0 reduced both the CGA content of the roots and the total amount of root hairs. The addition of exogenous CGA restored root hair formation in intact seedlings treated with AOPP. These results suggest that CGA is essential for root hair formation in lettuce seedlings.

  7. Auxin biosynthesis and storage forms

    Science.gov (United States)

    Strader, Lucia C.

    2013-01-01

    The plant hormone auxin drives plant growth and morphogenesis. The levels and distribution of the active auxin indole-3-acetic acid (IAA) are tightly controlled through synthesis, inactivation, and transport. Many auxin precursors and modified auxin forms, used to regulate auxin homeostasis, have been identified; however, very little is known about the integration of multiple auxin biosynthesis and inactivation pathways. This review discusses the many ways auxin levels are regulated through biosynthesis, storage forms, and inactivation, and the potential roles modified auxins play in regulating the bioactive pool of auxin to affect plant growth and development. PMID:23580748

  8. Hypericin: chemical synthesis and biosynthesis.

    Science.gov (United States)

    Huang, Lin-Fang; Wang, Zeng-Hui; Chen, Shi-Lin

    2014-02-01

    Hypericin is one of the most important phenanthoperylene quinones extracted mainly from plants of the genus Hypericum belonging to the sections Euhypericum and Campylosporus of Keller's classification. Widespread attention to the antiviral and anti-tumor properties of hypericin has spurred investigations of the chemical synthesis and biosynthesis of this unique compound. However, the synthetic strategies are challenging for organic and biological chemists. In this review, specific significant advances in total synthesis, semi-synthesis, and biosynthesis in the past decades are summarized. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  9. Root (Botany)

    Science.gov (United States)

    Robert R. Ziemer

    1981-01-01

    Plant roots can contribute significantly to the stability of steep slopes. They can anchor through the soil mass into fractures in bedrock, can cross zones of weakness to more stable soil, and can provide interlocking long fibrous binders within a weak soil mass. In deep soil, anchoring to bedrock becomes negligible, and lateral reinforcement predominates

  10. Automated Root Tracking with "Root System Analyzer"

    Science.gov (United States)

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent

  11. (vitamin B1) biosynthesis genes

    African Journals Online (AJOL)

    In this study, the gene transcripts of first two enzymes in thiamine biosynthesis pathway, THIC and THI1/THI4 were identified and amplified from oil palm tissues. Primers were designed based on sequence comparison of the genes from Arabidopsis thaliana, Zea mays, Oryza sativa and Alnus glutinosa. Oil palm's responses ...

  12. (-)-Menthol biosynthesis and molecular genetics

    Science.gov (United States)

    Croteau, Rodney B.; Davis, Edward M.; Ringer, Kerry L.; Wildung, Mark R.

    2005-12-01

    (-)-Menthol is the most familiar of the monoterpenes as both a pure natural product and as the principal and characteristic constituent of the essential oil of peppermint ( Mentha x piperita). In this paper, we review the biosynthesis and molecular genetics of (-)-menthol production in peppermint. In Mentha species, essential oil biosynthesis and storage is restricted to the peltate glandular trichomes (oil glands) on the aerial surfaces of the plant. A mechanical method for the isolation of metabolically functional oil glands, has provided a system for precursor feeding studies to elucidate pathway steps, as well as a highly enriched source of the relevant biosynthetic enzymes and of their corresponding transcripts with which cDNA libraries have been constructed to permit cloning and characterization of key structural genes. The biosynthesis of (-)-menthol from primary metabolism requires eight enzymatic steps, and involves the formation and subsequent cyclization of the universal monoterpene precursor geranyl diphosphate to the parent olefin (-)-(4 S)-limonene as the first committed reaction of the sequence. Following hydroxylation at C3, a series of four redox transformations and an isomerization occur in a general “allylic oxidation-conjugate reduction” scheme that installs three chiral centers on the substituted cyclohexanoid ring to yield (-)-(1 R, 3 R, 4 S)-menthol. The properties of each enzyme and gene of menthol biosynthesis are described, as are their probable evolutionary origins in primary metabolism. The organization of menthol biosynthesis is complex in involving four subcellular compartments, and regulation of the pathway appears to reside largely at the level of gene expression. Genetic engineering to up-regulate a flux-limiting step and down-regulate a side route reaction has led to improvement in the composition and yield of peppermint oil.

  13. Root disease management guidebook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    Forest tree root pathogens are widespread throughout all forested ecosystems in British Columbia. This guidebook provides a background to forest root disease management (including why, where, and how to manage root disease) and describes the necessary tools for managing root disease. It includes a review of the distribution of major root diseases in the province, host susceptibility and symptomology, and root disease and stand dynamics. The tools described include disease hazard and risk assessment, stratification surveys, and treatment methods. The major root diseases covered in the guide are Armillaria root disease, laminated root rot, Tomentosus root rot, blackstain root disease, and Annosus root disease.

  14. Combining Metabolic Profiling and Gene Expression Analysis to Reveal the Biosynthesis Site and Transport of Ginkgolides in Ginkgo biloba L.

    Science.gov (United States)

    Lu, Xu; Yang, Hua; Liu, Xinguang; Shen, Qian; Wang, Ning; Qi, Lian-wen; Li, Ping

    2017-01-01

    The most unique components of Ginkgo biloba extracts are terpene trilactones (TTLs) including ginkgolides and bilobalide. Study of TTLs biosynthesis has been stagnant in recent years. Metabolic profiling of 40 compounds, including TTLs, flavonoids, and phenolic acids, were globally analyzed in leaf, fibrous root, main root, old stem and young stem extracts of G. biloba. Most of the flavonoids were mainly distributed in the leaf and old stem. Most of phenolic acids were generally distributed among various tissues. The total content of TTLs decreased in the order of the leaf, fibrous root, main root, old stem and young stem. The TTLs were further analyzed in different parts of the main root and old stem. The content of TTLs decreases in the order of the main root periderm, the main root cortex and phloem and the main root xylem. In old stems, the content of TTLs in the cortex and phloem was much higher than both the old stem periderm and xylem. The expression patterns of five key genes in the ginkgolide biosynthetic pathway were measured by real-time quantitative polymerase chain reaction (RT-Q-PCR). Combining metabolic profiling and RT-Q-PCR, the results showed that the fibrous root and main root periderm tissues were the important biosynthesis sites of ginkgolides. Based on the above results, a model of the ginkgolide biosynthesis site and transport pathway in G. biloba was proposed. In this putative model, ginkgolides are synthesized in the fibrous root and main root periderm, and these compounds are then transported through the old stem cortex and phloem to the leaves. PMID:28603534

  15. George Stephanopoulos to give Cutchins Distinguished Lecture

    OpenAIRE

    Ho, Sookhan

    2006-01-01

    ABC News' chief Washington correspondent and"This Week" anchor George Stephanopoulos will give the Cutchins Distinguished Lecture at Virginia Tech on Thursday, March 16, 7:30 p.m., in Burruss Auditorium.

  16. Hormone symphony during root growth and development.

    Science.gov (United States)

    Garay-Arroyo, Adriana; De La Paz Sánchez, María; García-Ponce, Berenice; Azpeitia, Eugenio; Alvarez-Buylla, Elena R

    2012-12-01

    Hormones regulate plant growth and development in response to external environmental stimuli via complex signal transduction pathways, which in turn form complex networks of interaction. Several classes of hormones have been reported, and their activity depends on their biosynthesis, transport, conjugation, accumulation in the vacuole, and degradation. However, the activity of a given hormone is also dependent on its interaction with other hormones. Indeed, there is a complex crosstalk between hormones that regulates their biosynthesis, transport, and/or signaling functionality, although some hormones have overlapping or opposite functions. The plant root is a particularly useful system in which to study the complex role of plant hormones in the plastic control of plant development. Physiological, cellular, and molecular genetic approaches have been used to study the role of plant hormones in root meristem homeostasis. In this review, we discuss recent findings on the synthesis, signaling, transport of hormones and role during root development and examine the role of hormone crosstalk in maintaining homeostasis in the apical root meristem. Copyright © 2012 Wiley Periodicals, Inc.

  17. Locally Finite Root Supersystems

    OpenAIRE

    Yousofzadeh, Malihe

    2013-01-01

    We introduce the notion of locally finite root supersystems as a generalization of both locally finite root systems and generalized root systems. We classify irreducible locally finite root supersystems.

  18. Learning, Judgment, and the Rooted Particular

    Science.gov (United States)

    McCabe, David

    2012-01-01

    This article begins by acknowledging the general worry that scholarship in the humanities lacks the rigor and objectivity of other scholarly fields. In considering the validity of that criticism, I distinguish two models of learning: the covering law model exemplified by the natural sciences, and the model of rooted particularity that…

  19. MR imaging of nerve root impingement in the lumbar spine

    International Nuclear Information System (INIS)

    Teresi, L.M.; Bradley, W.G. Jr.; Bloze, A.E.; Davis, S.J.; Amster, J.; Berger, P.E.

    1990-01-01

    This paper determines the relationship between MR imaging findings of nerve root impingement, presenting symptoms, and physical examination findings, and physiologic data (DSEP and EMG) in a population of patients presented with classic radicular symptoms. Fifty-eight patients presenting with classic radicular pain were studied with MR imaging, DSER, and EMG, MR imaging was performed with a GE Signa imaging system with use of T1- and T2-weighted sequences and 5-mm-thick sections. Nerve root impingement in the subarticular recess (the root exiting the next lowest level) was distinguished from nerve root impingement in the superior intervertebral foramen (the root exiting the same level)

  20. CPC, a single-repeat R3 MYB, is a negative regulator of anthocyanin biosynthesis in Arabidopsis.

    Science.gov (United States)

    Zhu, Hui-Fen; Fitzsimmons, Karen; Khandelwal, Abha; Kranz, Robert G

    2009-07-01

    Single-repeat R3 MYB transcription factors like CPC (CAPRICE) are known to play roles in developmental processes such as root hair differentiation and trichome initiation. However, none of the six Arabidopsis single-repeat R3 MYB members has been reported to regulate flavonoid biosynthesis. We show here that CPC is a negative regulator of anthocyanin biosynthesis. In the process of using CPC to test GAL4-dependent driver lines, we observed a repression of anthocyanin synthesis upon GAL4-mediated CPC overexpression. We demonstrated that this is not due to an increase in nutrient uptake because of more root hairs. Rather, CPC expression level tightly controls anthocyanin accumulation. Microarray analysis on the whole genome showed that, of 37 000 features tested, 85 genes are repressed greater than three-fold by CPC overexpression. Of these 85, seven are late anthocyanin biosynthesis genes. Also, anthocyanin synthesis genes were shown to be down-regulated in 35S::CPC overexpression plants. Transient expression results suggest that CPC competes with the R2R3-MYB transcription factor PAP1/2, which is an activator of anthocyanin biosynthesis genes. This report adds anthocyanin biosynthesis to the set of programs that are under CPC control, indicating that this regulator is not only for developmental programs (e.g. root hairs, trichomes), but can influence anthocyanin pigment synthesis.

  1. A model for evolution and regulation of nicotine biosynthesis regulon in tobacco.

    Science.gov (United States)

    Kajikawa, Masataka; Sierro, Nicolas; Hashimoto, Takashi; Shoji, Tsubasa

    2017-06-03

    In tobacco, the defense alkaloid nicotine is produced in roots and accumulates mainly in leaves. Signaling mediated by jasmonates (JAs) induces the formation of nicotine via a series of structural genes that constitute a regulon and are coordinated by JA-responsive transcription factors of the ethylene response factor (ERF) family. Early steps in the pyrrolidine and pyridine biosynthesis pathways likely arose through duplication of the polyamine and nicotinamide adenine dinucleotide (NAD) biosynthetic pathways, respectively, followed by recruitment of duplicated primary metabolic genes into the nicotine biosynthesis regulon. Transcriptional regulation of nicotine biosynthesis by ERF and cooperatively-acting MYC2 transcription factors is implied by the frequency of cognate cis-regulatory elements for these factors in the promoter regions of the downstream structural genes. Indeed, a mutant tobacco with low nicotine content was found to have a large chromosomal deletion in a cluster of closely related ERF genes at the nicotine-controlling NICOTINE2 (NIC2) locus.

  2. GiA Roots: software for the high throughput analysis of plant root system architecture

    Science.gov (United States)

    2012-01-01

    Background Characterizing root system architecture (RSA) is essential to understanding the development and function of vascular plants. Identifying RSA-associated genes also represents an underexplored opportunity for crop improvement. Software tools are needed to accelerate the pace at which quantitative traits of RSA are estimated from images of root networks. Results We have developed GiA Roots (General Image Analysis of Roots), a semi-automated software tool designed specifically for the high-throughput analysis of root system images. GiA Roots includes user-assisted algorithms to distinguish root from background and a fully automated pipeline that extracts dozens of root system phenotypes. Quantitative information on each phenotype, along with intermediate steps for full reproducibility, is returned to the end-user for downstream analysis. GiA Roots has a GUI front end and a command-line interface for interweaving the software into large-scale workflows. GiA Roots can also be extended to estimate novel phenotypes specified by the end-user. Conclusions We demonstrate the use of GiA Roots on a set of 2393 images of rice roots representing 12 genotypes from the species Oryza sativa. We validate trait measurements against prior analyses of this image set that demonstrated that RSA traits are likely heritable and associated with genotypic differences. Moreover, we demonstrate that GiA Roots is extensible and an end-user can add functionality so that GiA Roots can estimate novel RSA traits. In summary, we show that the software can function as an efficient tool as part of a workflow to move from large numbers of root images to downstream analysis. PMID:22834569

  3. Transcriptome Analysis of Storage Roots and Fibrous Roots of the Traditional Medicinal Herb Callerya speciosa (Champ.) ScHot.

    Science.gov (United States)

    Xu, Li; Wang, Jiabin; Lei, Ming; Li, Li; Fu, Yunliu; Wang, Zhunian; Ao, Mengfei; Li, Zhiying

    2016-01-01

    Callerya speciosa (Champ.) ScHot is a woody perennial plant in Fabaceae, the roots of which are used medicinally. The storage roots of C. speciosa are derived from fibrous roots, but not all fibrous roots can develop into storage roots. To detect key genes involved in storage roots formation, we performed Illumina sequencing of the C. speciosa storage roots and fibrous roots. De novo assembly resulted in 161,926 unigenes, which were subsequently annotated by BLAST, GO and KEGG analyses. After expression profiling, 4538 differentially expressed genes were identified. The KEGG pathway enrichment analysis revealed changes in the biosynthesis of cytokinin, phenylpropanoid, starch, sucrose, flavone and other secondary metabolites. Transcription factor-related differentially expressed genes (DEGs) were also identified, including such gene families as GRAS, COL, MIKC, ERF, LBD, and NAC. The DEGs related to light signaling, starch, sugar, photohormones and cell wall-loosening might be involved in the formation of storage roots. This study provides the first transcriptome profiling of C. speciosa roots, data that will facilitate future research of root development and metabolites with medicinal value as well as the breeding of C. speciosa.

  4. Repetitive sequence environment distinguishes housekeeping genes.

    Science.gov (United States)

    Eller, C Daniel; Regelson, Moira; Merriman, Barry; Nelson, Stan; Horvath, Steve; Marahrens, York

    2007-04-01

    Housekeeping genes are expressed across a wide variety of tissues. Since repetitive sequences have been reported to influence the expression of individual genes, we employed a novel approach to determine whether housekeeping genes can be distinguished from tissue-specific genes by their repetitive sequence context. We show that Alu elements are more highly concentrated around housekeeping genes while various longer (>400-bp) repetitive sequences ("repeats"), including Long Interspersed Nuclear Element-1 (LINE-1) elements, are excluded from these regions. We further show that isochore membership does not distinguish housekeeping genes from tissue-specific genes and that repetitive sequence environment distinguishes housekeeping genes from tissue-specific genes in every isochore. The distinct repetitive sequence environment, in combination with other previously published sequence properties of housekeeping genes, was used to develop a method of predicting housekeeping genes on the basis of DNA sequence alone. Using expression across tissue types as a measure of success, we demonstrate that repetitive sequence environment is by far the most important sequence feature identified to date for distinguishing housekeeping genes.

  5. Distinguishing the Spending Preferences of Seniors.

    Science.gov (United States)

    Zimmer, Zachary; Chappell, Neena L.

    1996-01-01

    The consumer spending preferences of 1,406 senior Canadians were surveyed. Age distinguished those who had product-specific preferences. Income and health status separated those interested in recreational spending from those more interested in basic needs. Diversity of health and social characteristics in this population extends to their…

  6. Rapid molecular technique to distinguish Fusarium species

    CSIR Research Space (South Africa)

    Lodolo, EJ

    1993-03-01

    Full Text Available The nuclear DNA (nDNA) of different isolates of three closely related, toxin-producing Fusarium species, F. moniliforme, F. nygamai and F. napiforme, was compared to ascertain the sensitivity of a molecular method to distinguish these three species...

  7. Entropy of Mixing of Distinguishable Particles

    Science.gov (United States)

    Kozliak, Evguenii I.

    2014-01-01

    The molar entropy of mixing yields values that depend only on the number of mixing components rather than on their chemical nature. To explain this phenomenon using the logic of chemistry, this article considers mixing of distinguishable particles, thus complementing the well-known approach developed for nondistinguishable particles, for example,…

  8. Distinguishing intrauterine foetal demise versus abdominal ...

    African Journals Online (AJOL)

    Diagnosis of abdominal pregnancy always poses a clinical dilemma. Transvaginal ultrasound is the ideal radiological procedure in locating these pregnancies. However in resource limited setting, abdominal and pelvic ultrasounds can be the only available yet unreliable modalities for distinguishing intrauterine versus ...

  9. Ethylene Inhibits Root Elongation during Alkaline Stress through AUXIN1 and Associated Changes in Auxin Accumulation.

    Science.gov (United States)

    Li, Juan; Xu, Heng-Hao; Liu, Wen-Cheng; Zhang, Xiao-Wei; Lu, Ying-Tang

    2015-08-01

    Soil alkalinity causes major reductions in yield and quality of crops worldwide. The plant root is the first organ sensing soil alkalinity, which results in shorter primary roots. However, the mechanism underlying alkaline stress-mediated inhibition of root elongation remains to be further elucidated. Here, we report that alkaline conditions inhibit primary root elongation of Arabidopsis (Arabidopsis thaliana) seedlings by reducing cell division potential in the meristem zones and that ethylene signaling affects this process. The ethylene perception antagonist silver (Ag(+)) alleviated the inhibition of root elongation by alkaline stress. Moreover, the ethylene signaling mutants ethylene response1-3 (etr1-3), ethylene insensitive2 (ein2), and ein3-1 showed less reduction in root length under alkaline conditions, indicating a reduced sensitivity to alkalinity. Ethylene biosynthesis also was found to play a role in alkaline stress-mediated root inhibition; the ethylene overproducer1-1 mutant, which overproduces ethylene because of increased stability of 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASE5, was hypersensitive to alkaline stress. In addition, the ethylene biosynthesis inhibitor cobalt (Co(2+)) suppressed alkaline stress-mediated inhibition of root elongation. We further found that alkaline stress caused an increase in auxin levels by promoting expression of auxin biosynthesis-related genes, but the increase in auxin levels was reduced in the roots of the etr1-3 and ein3-1 mutants and in Ag(+)/Co(2+)-treated wild-type plants. Additional genetic and physiological data showed that AUXIN1 (AUX1) was involved in alkaline stress-mediated inhibition of root elongation. Taken together, our results reveal that ethylene modulates alkaline stress-mediated inhibition of root growth by increasing auxin accumulation by stimulating the expression of AUX1 and auxin biosynthesis-related genes. © 2015 American Society of Plant Biologists. All Rights Reserved.

  10. Transcriptomic and anatomical complexity of primary, seminal, and crown roots highlight root type-specific functional diversity in maize (Zea mays L.).

    Science.gov (United States)

    Tai, Huanhuan; Lu, Xin; Opitz, Nina; Marcon, Caroline; Paschold, Anja; Lithio, Andrew; Nettleton, Dan; Hochholdinger, Frank

    2016-02-01

    Maize develops a complex root system composed of embryonic and post-embryonic roots. Spatio-temporal differences in the formation of these root types imply specific functions during maize development. A comparative transcriptomic study of embryonic primary and seminal, and post-embryonic crown roots of the maize inbred line B73 by RNA sequencing along with anatomical studies were conducted early in development. Seminal roots displayed unique anatomical features, whereas the organization of primary and crown roots was similar. For instance, seminal roots displayed fewer cortical cell files and their stele contained more meta-xylem vessels. Global expression profiling revealed diverse patterns of gene activity across all root types and highlighted the unique transcriptome of seminal roots. While functions in cell remodeling and cell wall formation were prominent in primary and crown roots, stress-related genes and transcriptional regulators were over-represented in seminal roots, suggesting functional specialization of the different root types. Dynamic expression of lignin biosynthesis genes and histochemical staining suggested diversification of cell wall lignification among the three root types. Our findings highlight a cost-efficient anatomical structure and a unique expression profile of seminal roots of the maize inbred line B73 different from primary and crown roots. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  11. Localization and characterization of CYP76AE2 part of thapsigargin biosynthesis in Thapsia garganica

    DEFF Research Database (Denmark)

    Andersen, Trine Bundgaard; Martinez-Swatson, Karen Agatha; Rasmussen, Silas Anselm

    2018-01-01

    epikunzeaol into epidihydrocostunolide. Furthermore, we show that thapsigargin is likely to be stored in secretory ducts in the roots. Transcripts from TgTPS2 (epikunzeaol synthase) and TgCYP76AE2 in roots were only found in the epithelial cells lining these secretory ducts. This emphasizes the involvement...... Mipsagargin, currently in clinical trials. Knowledge of thapsigargin in planta storage and biosynthesis has so far been limited. Here we present the putative second step in thapsigargin biosynthesis, by showing that the cytochrome P450 TgCYP76AE2, transiently expressed in Nicotiana benthamiana, converts......The Mediterranean plant Thapsia garganica (dicot, Apiaceae), also known as Deadly carrot, produces the highly toxic compound thapsigargin. This compound is a potent inhibitor of the SERCA calcium pump in mammals, and is of industrial importance as the active moiety of the anticancer drug...

  12. Vitamin B biosynthesis in plants.

    Science.gov (United States)

    Roje, Sanja

    2007-07-01

    The vitamin B complex comprises water-soluble enzyme cofactors and their derivatives that are essential contributors to diverse metabolic processes in plants as well as in animals and microorganisms. Seven vitamins form this complex: B1 (thiamin (1)), B2 (riboflavin (2)), B3 (niacin (3)), B5 (pantothenic acid (4)), B6 (pyridoxine, pyridoxal (5), and pyridoxamine), B8 (biotin (6)), and B9 (folate (7)). All seven B vitamins are required in the human diet for proper nutrition because humans lack enzymes to synthesize these compounds de novo. This review aims to summarize the present knowledge of vitamin B biosynthesis in plants.

  13. Seedling root targets

    Science.gov (United States)

    Diane L. Haase

    2011-01-01

    Roots are critical to seedling performance after outplanting. Although root quality is not as quick and simple to measure as shoot quality, target root characteristics should be included in any seedling quality assessment program. This paper provides a brief review of root characteristics most commonly targeted for operational seedling production. These are: root mass...

  14. Biosynthesis of bacterial aromatic polyketides.

    Science.gov (United States)

    Zhan, Jixun

    2009-01-01

    Aromatic polyketides represent important members of the family of polyketides, which have displayed a wide assortment of bioactive properties, such as antibacterial, antitumor, and antiviral activities. Bacterial aromatic polyketides are mainly synthesized by type II polyketide synthases (PKSs). Whereas malonyl-CoA is exclusively used as the extender unit, starter units can vary in different aromatic polyketide biosynthetic pathways, leading to a variety of polyketide backbones. Once the polyketide chains are elongated by the minimal PKSs to the full length, the immediate tailoring enzymes including ketoreductases, oxygenases and cyclases will work on the nascent chains to form aromatic structures, which will be further decorated by those late tailoring enzymes such as methyltransferases and glycosyltransferases. The mechanistic studies on the biosynthetic pathways of aromatic polyketides such as oxytetracycline and pradimicin A have been extensively carried out in recent years. Engineered biosynthesis of novel "unnatural" polyketides has been achieved in heterologous hosts such as Streptomyces coelicolor and Escherichia coli. This review covers the most recent advances in aromatic polyketide biosynthesis, which provide new enzymes or methods for building novel polyketide biosynthetic machinery.

  15. Fatty acid biosynthesis in actinomycetes

    Science.gov (United States)

    Gago, Gabriela; Diacovich, Lautaro; Arabolaza, Ana; Tsai, Shiou-Chuan; Gramajo, Hugo

    2011-01-01

    All organisms that produce fatty acids do so via a repeated cycle of reactions. In mammals and other animals, these reactions are catalyzed by a type I fatty acid synthase (FAS), a large multifunctional protein to which the growing chain is covalently attached. In contrast, most bacteria (and plants) contain a type II system in which each reaction is catalyzed by a discrete protein. The pathway of fatty acid biosynthesis in Escherichia coli is well established and has provided a foundation for elucidating the type II FAS pathways in other bacteria (White et al., 2005). However, fatty acid biosynthesis is more diverse in the phylum Actinobacteria: Mycobacterium, possess both FAS systems while Streptomyces species have only the multi-enzyme FAS II system and Corynebacterium species exclusively FAS I. In this review we present an overview of the genome organization, biochemical properties and physiological relevance of the two FAS systems in the three genera of actinomycetes mentioned above. We also address in detail the biochemical and structural properties of the acyl-CoA carboxylases (ACCases) that catalyzes the first committed step of fatty acid synthesis in actinomycetes, and discuss the molecular bases of their substrate specificity and the structure-based identification of new ACCase inhibitors with anti-mycobacterial properties. PMID:21204864

  16. Xyloglucan, galactomannan, glucuronoxylan, and rhamnogalacturonan I do not have identical structures in soybean root and root hair cell walls.

    Science.gov (United States)

    Muszyński, Artur; O'Neill, Malcolm A; Ramasamy, Easwaran; Pattathil, Sivakumar; Avci, Utku; Peña, Maria J; Libault, Marc; Hossain, Md Shakhawat; Brechenmacher, Laurent; York, William S; Barbosa, Rommel M; Hahn, Michael G; Stacey, Gary; Carlson, Russell W

    2015-11-01

    Chemical analyses and glycome profiling demonstrate differences in the structures of the xyloglucan, galactomannan, glucuronoxylan, and rhamnogalacturonan I isolated from soybean ( Glycine max ) roots and root hair cell walls. The root hair is a plant cell that extends only at its tip. All other root cells have the ability to grow in different directions (diffuse growth). Although both growth modes require controlled expansion of the cell wall, the types and structures of polysaccharides in the walls of diffuse and tip-growing cells from the same plant have not been determined. Soybean (Glycine max) is one of the few plants whose root hairs can be isolated in amounts sufficient for cell wall chemical characterization. Here, we describe the structural features of rhamnogalacturonan I, rhamnogalacturonan II, xyloglucan, glucomannan, and 4-O-methyl glucuronoxylan present in the cell walls of soybean root hairs and roots stripped of root hairs. Irrespective of cell type, rhamnogalacturonan II exists as a dimer that is cross-linked by a borate ester. Root hair rhamnogalacturonan I contains more neutral oligosaccharide side chains than its root counterpart. At least 90% of the glucuronic acid is 4-O-methylated in root glucuronoxylan. Only 50% of this glycose is 4-O-methylated in the root hair counterpart. Mono O-acetylated fucose-containing subunits account for at least 60% of the neutral xyloglucan from root and root hair walls. By contrast, a galacturonic acid-containing xyloglucan was detected only in root hair cell walls. Soybean homologs of the Arabidopsis xyloglucan-specific galacturonosyltransferase are highly expressed only in root hairs. A mannose-rich polysaccharide was also detected only in root hair cell walls. Our data demonstrate that the walls of tip-growing root hairs cells have structural features that distinguish them from the walls of other roots cells.

  17. TiO2 nanoparticle biosynthesis and its physiological effect on mung bean (Vigna radiata L.

    Directory of Open Access Journals (Sweden)

    Ramesh Raliya

    2015-03-01

    Full Text Available TiO2 nanoparticle (NPs biosynthesis is a low cost, ecofriendly approach developed using the fungi Aspergillus flavus TFR 7. To determine whether TiO2 NPs is suitable for nutrient, we conducted a two part study; biosynthesis of TiO2 NP and evaluates their influence on mung bean. The characterized TiO2 NPs were foliar sprayed at 10 mgL−1 concentration on the leaves of 14 days old mung bean plants. A significant improvement was observed in shoot length (17.02%, root length (49.6%, root area (43%, root nodule (67.5%, chlorophyll content (46.4% and total soluble leaf protein (94% as a result of TiO2 NPs application. In the rhizosphere microbial population increased by 21.4–48.1% and activity of acid phosphatase (67.3%, alkaline phosphatase (72%, phytase (64% and dehydrogenase (108.7% enzyme was observed over control in six weeks old plants owing to application of TiO2 NPs. A possible mechanism has also been hypothesized for TiO2 NPs biosynthesis.

  18. Activity recognition from minimal distinguishing subsequence mining

    Science.gov (United States)

    Iqbal, Mohammad; Pao, Hsing-Kuo

    2017-08-01

    Human activity recognition is one of the most important research topics in the era of Internet of Things. To separate different activities given sensory data, we utilize a Minimal Distinguishing Subsequence (MDS) mining approach to efficiently find distinguishing patterns among different activities. We first transform the sensory data into a series of sensor triggering events and operate the MDS mining procedure afterwards. The gap constraints are also considered in the MDS mining. Given the multi-class nature of most activity recognition tasks, we modify the MDS mining approach from a binary case to a multi-class one to fit the need for multiple activity recognition. We also study how to select the best parameter set including the minimal and the maximal support thresholds in finding the MDSs for effective activity recognition. Overall, the prediction accuracy is 86.59% on the van Kasteren dataset which consists of four different activities for recognition.

  19. Increased de novo riboflavin synthesis and hydrolysis of FMN are involved in riboflavin secretion from Hyoscyamus albus hairy roots under iron deficiency

    OpenAIRE

    Higa, Ataru; Khandakar, Jebunnahar; Mori, Yuko; Kitamura, Yoshie

    2012-01-01

    Riboflavin secretion by Hyoscyamus albus hairy roots under Fe deficiency was examined to determine where riboflavin is produced and whether production occurs via an enhancement of riboflavin biosynthesis or a stimulation of flavin mononucleotide (FMN) hydrolysis. Confocal fluorescent microscopy showed that riboflavin was mainly localized in the epidermis and cortex of the root tip and, at the cellular level, in the apoplast. The expressions of three genes involved in the de novo biosynthesis ...

  20. Two Cycloartenol Synthases for Phytosterol Biosynthesis in Polygala tenuifolia Willd

    Directory of Open Access Journals (Sweden)

    Mei Lan Jin

    2017-11-01

    Full Text Available Oxidosqualene cyclases (OSCs are enzymes that play a key role in control of the biosynthesis of phytosterols and triterpene saponins. In order to uncover OSC genes from Polygala tenuifolia seedlings induced by methyl jasmonate (MeJA, RNA-sequencing analysis was performed using the Illumina sequencing platform. A total of 148,488,632 high-quality reads from two samples (control and the MeJA treated were generated. We screened genes related to phytosterol and triterpene saponin biosynthesis and analyzed the transcriptional changes of differentially expressed unigene (DEUG values calculated by fragments per kilobase million (FPKM. In our datasets, two full-length cDNAs of putative OSC genes, PtCAS1, and PtCAS2, were found, in addition to the PtBS (β-amyrin synthase gene reported in our previous studies and the two cycloartenol synthase genes of P. tenuifolia. All genes were isolated and characterized in yeast cells. The functional expression of the two PtCAS genes in yeast cells showed that the genes all produce a cycloartenol as the sole product. When qRT-PCR analysis from different tissues was performed, the expressions of PtCAS1 and PtCAS2 were highest in flowers and roots, respectively. After MeJA treatment, the transcripts of PtCAS1 and PtCAS2 genes increased by 1.5- and 2-fold, respectively. Given these results, we discuss the potential roles of the two PtCAS genes in relation to triterpenoid biosynthesis.

  1. MRE: a web tool to suggest foreign enzymes for the biosynthesis pathway design with competing endogenous reactions in mind

    KAUST Repository

    Kuwahara, Hiroyuki

    2016-04-29

    To rationally design a productive heterologous biosynthesis system, it is essential to consider the suitability of foreign reactions for the specific endogenous metabolic infrastructure of a host. We developed a novel web server, called MRE, which, for a given pair of starting and desired compounds in a given chassis organism, ranks biosynthesis routes from the perspective of the integration of new reactions into the endogenous metabolic system. For each promising heterologous biosynthesis pathway, MRE suggests actual enzymes for foreign metabolic reactions and generates information on competing endogenous reactions for the consumption of metabolites. These unique, chassis-centered features distinguish MRE from existing pathway design tools and allow synthetic biologists to evaluate the design of their biosynthesis systems from a different angle. By using biosynthesis of a range of high-value natural products as a case study, we show that MRE is an effective tool to guide the design and optimization of heterologous biosynthesis pathways. The URL of MRE is http://www.cbrc.kaust.edu.sa/mre/.

  2. Estimation of fine-root production using rates of diameter-dependent root mortality, decomposition and thickening in forests.

    Science.gov (United States)

    Van Do, Tran; Osawa, Akira; Sato, Tamotsu

    2016-04-01

    Current studies indicate that fine roots of different diameter classes show different rates of decomposition. This study developed a new method to estimate fine-root production by considering the difference in the production of fine roots of two size classes, fine roots thinner than 1 mm and those between 1 and 2 mm, and their corresponding rates of decomposition. A litter bag experiment was used to estimate the decomposition rates, while the sequential soil core technique was used to identify mass values of live roots and dead roots at a given period of observation. The continuous inflow method was applied to estimate the amount of root decomposition, mortality and production with a framework of two diameter classes of fine roots and for quantification of the amount of mass transfer from the thicker fine-root class to the coarser root category (>2 mm). The results indicated that the estimate of fine-root production was greater when two size classes of fine roots were distinguished. Using a framework of two size classes developed in this study resulted in 21.3% higher fine-root production than a method that did not recognize fine-root size classes or mass transfer to the category of coarse roots. In addition, using shorter collection intervals led to higher production estimates than longer intervals. The production estimate with a 1-month interval was 21.4% higher than that with a 6-month interval. We consider that the use of the sequential soil core technique with continuous inflow estimate method by differentiating size classes of fine roots is likely to minimize the underestimation of the parameters of fine-root dynamics by accounting for decomposition and mortality of fine roots more appropriately. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Regulatory variability of camalexin biosynthesis.

    Science.gov (United States)

    Schuhegger, Regina; Rauhut, Thomas; Glawischnig, Erich

    2007-05-01

    The anthranilate synthase ASA1, CYP79B2 and CYP71B15 (PAD3) are biosynthetic genes of the Arabidopsis phytoalexin camalexin, which are induced after pathogen infection and abiotic treatments like silver nitrate spraying. The natural variation of camalexin biosynthesis in response to Pseudomonas syringae infection was determined in several ecotypes, and differential CYP71B15 regulation as a potential basis for this variation was investigated. The expression of camalexin biosynthetic genes was restricted to the tissue undergoing cell death. After droplet infection with Alternaria alternata, a potent camalexin inducer in the Col-0 ecotype, camalexin formation and the induction of ASA1, CYP79B2 and CYP71B15 were strictly co-localized with the infection site.

  4. Biosynthesis of therapeutic natural products using synthetic biology.

    Science.gov (United States)

    Awan, Ali R; Shaw, William M; Ellis, Tom

    2016-10-01

    Natural products are a group of bioactive structurally diverse chemicals produced by microorganisms and plants. These molecules and their derivatives have contributed to over a third of the therapeutic drugs produced in the last century. However, over the last few decades traditional drug discovery pipelines from natural products have become far less productive and far more expensive. One recent development with promise to combat this trend is the application of synthetic biology to therapeutic natural product biosynthesis. Synthetic biology is a young discipline with roots in systems biology, genetic engineering, and metabolic engineering. In this review, we discuss the use of synthetic biology to engineer improved yields of existing therapeutic natural products. We further describe the use of synthetic biology to combine and express natural product biosynthetic genes in unprecedented ways, and how this holds promise for opening up completely new avenues for drug discovery and production. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Root isoflavonoids and hairy root transformation influence key bacterial taxa in the soybean rhizosphere.

    Science.gov (United States)

    White, Laura J; Ge, Xijin; Brözel, Volker S; Subramanian, Senthil

    2017-04-01

    Rhizodeposits play a key role in shaping rhizosphere microbial communities. In soybean, isoflavonoids are a key rhizodeposit component that aid in plant defense and enable symbiotic associations with rhizobia. However, it is uncertain if and how they influence rhizosphere microbial communities. Isoflavonoid biosynthesis was silenced via RNA interference of isoflavone synthase in soybean hairy root composite plants. Rhizosphere soil fractions tightly associated with roots were isolated, and PCR amplicons from 16S rRNA gene variable regions V1-V3 and V3-V5 from these fractions were sequenced using 454. The resulting data was resolved using MOTHUR and vegan to identify bacterial taxa and evaluate changes in rhizosphere bacterial communities. The soybean rhizosphere was enriched in Proteobacteria and Bacteroidetes, and had relatively lower levels of Actinobacteria and Acidobacteria compared with bulk soil. Isoflavonoids had a small effect on bacterial community structure, and in particular on the abundance of Xanthomonads and Comamonads. The effect of hairy root transformation on rhizosphere bacterial communities was largely similar to untransformed plant roots with approximately 74% of the bacterial families displaying similar colonization underscoring the suitability of this technique to evaluate the influence of plant roots on rhizosphere bacterial communities. However, hairy root transformation had notable influence on Sphingomonads and Acidobacteria. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Ethylene is differentially regulated during sugar beet germination and affects early root growth in a dose-dependent manner.

    Science.gov (United States)

    Abts, Willem; Van de Poel, Bram; Vandenbussche, Bert; De Proft, Maurice P

    2014-10-01

    By integrating molecular, biochemical, and physiological data, ethylene biosynthesis in sugar beet was shown to be differentially regulated, affecting root elongation in a concentration-dependent manner. There is a close relation between ethylene production and seedling growth of sugar beet (Beta vulgaris L.), yet the exact function of ethylene during this early developmental stage is still unclear. While ethylene is mostly considered to be a root growth inhibitor, we found that external 1-aminocyclopropane-1-carboxylic acid (ACC) regulates root growth in sugar beet in a concentration-dependent manner: low concentrations stimulate root growth while high concentrations inhibit root growth. These results reveal that ethylene action during root elongation is strongly concentration dependent. Furthermore our detailed study of ethylene biosynthesis kinetics revealed a very strict gene regulation pattern of ACC synthase (ACS) and ACC oxidase (ACO), in which ACS is the rate liming step during sugar beet seedling development.

  7. Biosynthesis of secondary metabolites in sugarcane

    Directory of Open Access Journals (Sweden)

    S.C. França

    2001-12-01

    Full Text Available A set of genes related to secondary metabolism was extracted from the sugarcane expressed sequence tag (SUCEST database and was used to investigate both the gene expression pattern of key enzymes regulating the main biosynthetic secondary metabolism pathways and the major classes of metabolites involved in the response of sugarcane to environmental and developmental cues. The SUCEST database was constructed with tissues in different physiological conditions which had been collected under varied situation of environmental stress. This database allows researchers to identify and characterize the expressed genes of a wide range of putative enzymes able to catalyze steps in the phenylpropanoid, isoprenoid and other pathways of the special metabolic mechanisms involved in the response of sugarcane to environmental changes. Our results show that sugarcane cDNAs encoded putative ultra-violet induced sesquiterpene cyclases (SC; chalcone synthase (CHS, the first enzyme in the pathway branch for flavonoid biosynthesis; isoflavone synthase (IFS, involved in plant defense and root nodulation; isoflavone reductase (IFR, a key enzyme in phenylpropanoid phytoalexin biosynthesis; and caffeic acid-O-methyltransferase, a key enzyme in the biosynthesis of lignin cell wall precursors. High levels of CHS transcripts from plantlets infected with Herbaspirillum rubri or Gluconacetobacter diazotroficans suggests that agents of biotic stress can elicit flavonoid biosynthesis in sugarcane. From this data we have predicted the profile of isoprenoid and phenylpropanoid metabolism in sugarcane and pointed the branches of secondary metabolism activated during tissue-specific stages of development and the adaptive response of sugarcane to agents of biotic and abiotic stress, although our assignment of enzyme function should be confirmed by careful biochemical and genetic supporting evidence.Este trabalho foi realizado com os objetivos de gerar uma coleção de genes

  8. Distinguishing between symbiotic stars and planetary nebulae

    Science.gov (United States)

    Iłkiewicz, K.; Mikołajewska, J.

    2017-10-01

    Context. The number of known symbiotic stars (SySt) is still significantly lower than their predicted population. One of the main problems in finding the total population of SySt is the fact that their spectrum can be confused with other objects, such as planetary nebulae (PNe) or dense H II regions. This problem is reinforced by the fact that in a significant fraction of established SySt the emission lines used to distinguish them from other objects are not present. Aims: We aim at finding new diagnostic diagrams that could help separate SySt from PNe. Additionally, we examine a known sample of extragalactic PNe for candidate SySt. Methods: We employed emission line fluxes of known SySt and PNe from the literature. Results: We found that among the forbidden lines in the optical region of spectrum, only the [O III] and [N II] lines can be used as a tool for distinguishing between SySt and PNe, which is consistent with the fact that they have the highest critical densities. The most useful diagnostic that we propose is based on He I lines, which are more common and stronger in SySt than forbidden lines. All these useful diagnostic diagrams are electron density indicators that better distinguish PNe and ionized symbiotic nebulae. Moreover, we found six new candidate SySt in the Large Magellanic Cloud and one in M 81. If confirmed, the candidate in M 81 would be the farthest known SySt thus far.

  9. Distinguished figures in mechanism and machine science

    CERN Document Server

    2014-01-01

    This book is composed of chapters that focus specifically on technological developments by distinguished figures in the history of MMS (Mechanism and Machine Science).  Biographies of well-known scientists are also included to describe their efforts and experiences, and surveys of their work and achievements, and a modern interpretation of their legacy are presented. After the first two volumes, the papers in this third volume again cover a wide range within the field of the History of Mechanical Engineering with specific focus on MMS and will be of interest and motivation to the work (historical or not) of many.

  10. computer-aided root aided root aided root aided root-locus

    African Journals Online (AJOL)

    User

    equation are the same as the poles of the close loop system. Ideally, a desired performance can be achieved a control system by adjusting the location of roots in the s-plane by varying one or mo system parameters. Root-locus Method is a line. 8023278605. AIDED ROOT. AIDED ROOT-LOCUS NUMERICAL TECHNIQUE.

  11. ROOT Reference Documentation

    CERN Document Server

    Fuakye, Eric Gyabeng

    2017-01-01

    A ROOT Reference Documentation has been implemented to generate all the lists of libraries needed for each ROOT class. Doxygen has no option to generate or add the lists of libraries for each ROOT class. Therefore shell scripting and a basic C++ program was employed to import the lists of libraries needed by each ROOT class.

  12. Dynamic transcriptional profiling provides insights into tuberous root development in Rehmannia glutinosa

    Directory of Open Access Journals (Sweden)

    Peng eSun

    2015-06-01

    Full Text Available Rehmannia glutinosa, a herb of the Scrophulariaceae family, is widely cultivated in the Northern part of China. The tuberous root has well known medicinal properties; however, yield and quality are threatened by abiotic and biotic stresses. Understanding the molecular process of tuberous root development may help identify novel targets for its control. In the present study, we used Illumina sequencing and de novo assembly strategies to obtain a reference transcriptome that is relevant to tuberous root development. We then conducted RNA-seq quantification analysis to determine gene expression profiles of the adventitious root (AR, thickening adventitious root (TAR, and the developing tuberous root (DTR. Expression profiling identified a total of 6,974 differentially expressed unigenes during root developmental. Bioinformatics analysis and gene expression profiling revealed changes in phenylpropanoid biosynthesis, starch and sucrose metabolism, and plant hormone biosynthesis during root development. Moreover, we identified and allocated putative functions to the genes involved in tuberous root development, including genes related to major carbohydrate metabolism, hormone metabolism, and transcription regulation. The present study provides the initial description of gene expression profiles of AR, TAR, and DTR, which facilitates identification of genes of interest. Moreover, our work provides insights into the molecular mechanisms underlying tuberous root development and may assist in the design and development of improved breeding schemes for different R. glutinosa varieties through genetic manipulation.

  13. Fine-tuning of root elongation by ethylene: a tool to study dynamic structure-function relationships between root architecture and nitrate absorption.

    Science.gov (United States)

    Le Deunff, Erwan; Lecourt, Julien; Malagoli, Philippe

    2016-07-12

    Recently developed genetic and pharmacological approaches have been used to explore [Formula: see text]/ethylene signalling interactions and how the modifications in root architecture by pharmacological modulation of ethylene biosynthesis affect nitrate uptake. Structure-function studies combined with recent approaches to chemical genomics highlight the non-specificity of commonly used inhibitors of ethylene biosynthesis such as AVG (l-aminoethoxyvinylglycine). Indeed, AVG inhibits aminotransferases such as ACC synthase (ACS) and tryptophan aminotransferase (TAA) involved in ethylene and auxin biosynthesis but also some aminotransferases implied in nitrogen (N) metabolism. In this framework, it can be assumed that the products of nitrate assimilation and hormones may interact through a hub in carbon (C) and N metabolism to drive the root morphogenetic programme (RMP). Although ethylene/auxin interactions play a major role in cell division and elongation in root meristems, shaping of the root system depends also on energetic considerations. Based on this finding, the analysis is extended to nutrient ion-hormone interactions assuming a fractal or constructal model for root development. Therefore, the tight control of root structure-function in the RMP may explain why over-expressing nitrate transporter genes to decouple structure-function relationships and improve nitrogen use efficiency (NUE) has been unsuccessful. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. The Role of Auxin-Ethylene Crosstalk in Orchestrating Primary Root Elongation in Sugar Beet

    Science.gov (United States)

    Abts, Willem; Vandenbussche, Bert; De Proft, Maurice P.; Van de Poel, Bram

    2017-01-01

    It is well-established in Arabidopsis and other species that ethylene inhibits root elongation through the action of auxin. In sugar beet (Beta vulgaris L.) ethylene promotes root elongation in a concentration dependent manner. However, the crosstalk between ethylene and auxin remains unknown during sugar beet seedling development. Our experiments have shown that exogenously applied auxin (indole-3-acetic acid; IAA) also stimulates root elongation. We also show that auxin promotes ethylene biosynthesis leading to longer roots. We have further demonstrated that the auxin treatment stimulates ethylene production by redirecting the pool of available 1-aminocyclopropane-1-carboxylic acid (ACC) toward ethylene instead of malonyl-ACC (MACC) resulting in a prolonged period of high rates of ethylene production and subsequently a longer root. On the other hand we have also shown that endogenous IAA levels were not affected by an ACC treatment during germination. All together our findings suggest that the general model for auxin-ethylene crosstalk during early root development, where ethylene controls auxin biosynthesis and transport, does not occur in sugar beet. On the contrary, we have shown that the opposite, where auxin stimulates ethylene biosynthesis, is true for sugar beet root development. PMID:28424722

  15. Altered Phenylpropanoid Metabolism in the Maize Lc-Expressed Sweet Potato (Ipomoea batatas) Affects Storage Root Development.

    Science.gov (United States)

    Wang, Hongxia; Yang, Jun; Zhang, Min; Fan, Weijuan; Firon, Nurit; Pattanaik, Sitakanta; Yuan, Ling; Zhang, Peng

    2016-01-04

    There is no direct evidence of the effect of lignin metabolism on early storage root development in sweet potato. In this study, we found that heterologous expression of the maize leaf color (Lc) gene in sweet potato increased anthocyanin pigment accumulation in the whole plant and resulted in reduced size with an increased length/width ratio, low yield and less starch content in the early storage roots. RT-PCR analysis revealed dramatic up-regulation of the genes involved in the lignin biosynthesis pathway in developing storage roots, leading to greater lignin content in the Lc transgenic lines, compared to the wild type. This was also evidenced by the enhanced lignification of vascular cells in the early storage roots. Furthermore, increased expression of the β-amylase gene in leaves and storage roots also accelerated starch degradation and increased the sugar use efficiency, providing more energy and carbohydrate sources for lignin biosynthesis in the Lc transgenic sweet potato. Lesser starch accumulation was observed in the developing storage roots at the initiation stage in the Lc plants. Our study provides experimental evidence of the basic carbohydrate metabolism underlying the development of storage roots, which is the transformation of lignin biosynthesis to starch biosynthesis.

  16. Altered Phenylpropanoid Metabolism in the Maize Lc-Expressed Sweet Potato (Ipomoea batatas) Affects Storage Root Development

    Science.gov (United States)

    Wang, Hongxia; Yang, Jun; Zhang, Min; Fan, Weijuan; Firon, Nurit; Pattanaik, Sitakanta; Yuan, Ling; Zhang, Peng

    2016-01-01

    There is no direct evidence of the effect of lignin metabolism on early storage root development in sweet potato. In this study, we found that heterologous expression of the maize leaf color (Lc) gene in sweet potato increased anthocyanin pigment accumulation in the whole plant and resulted in reduced size with an increased length/width ratio, low yield and less starch content in the early storage roots. RT-PCR analysis revealed dramatic up-regulation of the genes involved in the lignin biosynthesis pathway in developing storage roots, leading to greater lignin content in the Lc transgenic lines, compared to the wild type. This was also evidenced by the enhanced lignification of vascular cells in the early storage roots. Furthermore, increased expression of the β-amylase gene in leaves and storage roots also accelerated starch degradation and increased the sugar use efficiency, providing more energy and carbohydrate sources for lignin biosynthesis in the Lc transgenic sweet potato. Lesser starch accumulation was observed in the developing storage roots at the initiation stage in the Lc plants. Our study provides experimental evidence of the basic carbohydrate metabolism underlying the development of storage roots, which is the transformation of lignin biosynthesis to starch biosynthesis. PMID:26727353

  17. Yucasin is a potent inhibitor of YUCCA, a key enzyme in auxin biosynthesis.

    Science.gov (United States)

    Nishimura, Takeshi; Hayashi, Ken-Ichiro; Suzuki, Hiromi; Gyohda, Atsuko; Takaoka, Chihiro; Sakaguchi, Yusuke; Matsumoto, Sachiko; Kasahara, Hiroyuki; Sakai, Tatsuya; Kato, Jun-Ichi; Kamiya, Yuji; Koshiba, Tomokazu

    2014-02-01

    Indole-3-acetic acid (IAA), an auxin plant hormone, is biosynthesized from tryptophan. The indole-3-pyruvic acid (IPyA) pathway, involving the tryptophan aminotransferase TAA1 and YUCCA (YUC) enzymes, was recently found to be a major IAA biosynthetic pathway in Arabidopsis. TAA1 catalyzes the conversion of tryptophan to IPyA, and YUC produces IAA from IPyA. Using a chemical biology approach with maize coleoptiles, we identified 5-(4-chlorophenyl)-4H-1,2,4-triazole-3-thiol (yucasin) as a potent inhibitor of IAA biosynthesis in YUC-expressing coleoptile tips. Enzymatic analysis of recombinant AtYUC1-His suggested that yucasin strongly inhibited YUC1-His activity against the substrate IPyA in a competitive manner. Phenotypic analysis of Arabidopsis YUC1 over-expression lines (35S::YUC1) demonstrated that yucasin acts in IAA biosynthesis catalyzed by YUC. In addition, 35S::YUC1 seedlings showed resistance to yucasin in terms of root growth. A loss-of-function mutant of TAA1, sav3-2, was hypersensitive to yucasin in terms of root growth and hypocotyl elongation of etiolated seedlings. Yucasin combined with the TAA1 inhibitor l-kynurenine acted additively in Arabidopsis seedlings, producing a phenotype similar to yucasin-treated sav3-2 seedlings, indicating the importance of IAA biosynthesis via the IPyA pathway in root growth and leaf vascular development. The present study showed that yucasin is a potent inhibitor of YUC enzymes that offers an effective tool for analyzing the contribution of IAA biosynthesis via the IPyA pathway to plant development and physiological processes. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  18. Fluorescent pigment distinguishes between sibling snail species.

    Science.gov (United States)

    Seki, Keiichi; Wiwegweaw, Amporn; Asami, Takahiro

    2008-12-01

    Traditional taxonomy of shell-bearing molluscs does not generally use soft-body coloration. However, the land snails Bradybaena pellucida and B. similaris have been distinguished only on the basis of the color of the soft-body visible through the shell. Thus, the taxonomic status of the two species has traditionally been questionable. We found that dense spots of pigments embedded in the dorsal mantle are responsible for the yellow coloration of B. pellucida . Similar spots in B. similaris are white and less densely aggregated in whorls further from the apex, and the brown color of the hepatopancreas is visible through the shell. The yellow pigments of B. pellucida seep out with mucus from the body in natural and laboratory conditions. The two species became externally indistinguishable after 30 days of laboratory feeding, because the yellow spots disappeared in B. pellucida and the color of the hepatopancreas changed from dark brown to pale brown in both species. Irradiation with ultraviolet A demonstrated that the yellow pigment of B. pellucida fluoresces. Adult specimens of the two species were distinct in penial microsculpture, with F(1) hybrids intermediate in form. Populations of the two species differed significantly in allelic frequencies at four allozyme loci. Therefore, B. pellucida and B. similaris are morphologically and genetically distinct. The fluorescent yellow pigment distinguishes B. pellucida from B. similaris under natural conditions despite its environmental dependence.

  19. Cellular oxido-reductive proteins of Chlamydomonas reinhardtii control the biosynthesis of silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Barwal Indu

    2011-12-01

    Full Text Available Abstract Background Elucidation of molecular mechanism of silver nanoparticles (SNPs biosynthesis is important to control its size, shape and monodispersity. The evaluation of molecular mechanism of biosynthesis of SNPs is of prime importance for the commercialization and methodology development for controlling the shape and size (uniform distribution of SNPs. The unicellular algae Chlamydomonas reinhardtii was exploited as a model system to elucidate the role of cellular proteins in SNPs biosynthesis. Results The C. reinhardtii cell free extract (in vitro and in vivo cells mediated synthesis of silver nanoparticles reveals SNPs of size range 5 ± 1 to 15 ± 2 nm and 5 ± 1 to 35 ± 5 nm respectively. In vivo biosynthesized SNPs were localized in the peripheral cytoplasm and at one side of flagella root, the site of pathway of ATP transport and its synthesis related enzymes. This provides an evidence for the involvement of oxidoreductive proteins in biosynthesis and stabilization of SNPs. Alteration in size distribution and decrease of synthesis rate of SNPs in protein-depleted fractions confirmed the involvement of cellular proteins in SNPs biosynthesis. Spectroscopic and SDS-PAGE analysis indicate the association of various proteins on C. reinhardtii mediated in vivo and in vitro biosynthesized SNPs. We have identified various cellular proteins associated with biosynthesized (in vivo and in vitro SNPs by using MALDI-MS-MS, like ATP synthase, superoxide dismutase, carbonic anhydrase, ferredoxin-NADP+ reductase, histone etc. However, these proteins were not associated on the incubation of pre-synthesized silver nanoparticles in vitro. Conclusion Present study provides the indication of involvement of molecular machinery and various cellular proteins in the biosynthesis of silver nanoparticles. In this report, the study is mainly focused towards understanding the role of diverse cellular protein in the synthesis and capping of silver

  20. Cellular oxido-reductive proteins of Chlamydomonas reinhardtii control the biosynthesis of silver nanoparticles.

    Science.gov (United States)

    Barwal, Indu; Ranjan, Peeyush; Kateriya, Suneel; Yadav, Subhash Chandra

    2011-12-07

    Elucidation of molecular mechanism of silver nanoparticles (SNPs) biosynthesis is important to control its size, shape and monodispersity. The evaluation of molecular mechanism of biosynthesis of SNPs is of prime importance for the commercialization and methodology development for controlling the shape and size (uniform distribution) of SNPs. The unicellular algae Chlamydomonas reinhardtii was exploited as a model system to elucidate the role of cellular proteins in SNPs biosynthesis. The C. reinhardtii cell free extract (in vitro) and in vivo cells mediated synthesis of silver nanoparticles reveals SNPs of size range 5 ± 1 to 15 ± 2 nm and 5 ± 1 to 35 ± 5 nm respectively. In vivo biosynthesized SNPs were localized in the peripheral cytoplasm and at one side of flagella root, the site of pathway of ATP transport and its synthesis related enzymes. This provides an evidence for the involvement of oxidoreductive proteins in biosynthesis and stabilization of SNPs. Alteration in size distribution and decrease of synthesis rate of SNPs in protein-depleted fractions confirmed the involvement of cellular proteins in SNPs biosynthesis. Spectroscopic and SDS-PAGE analysis indicate the association of various proteins on C. reinhardtii mediated in vivo and in vitro biosynthesized SNPs. We have identified various cellular proteins associated with biosynthesized (in vivo and in vitro) SNPs by using MALDI-MS-MS, like ATP synthase, superoxide dismutase, carbonic anhydrase, ferredoxin-NADP⁺ reductase, histone etc. However, these proteins were not associated on the incubation of pre-synthesized silver nanoparticles in vitro. Present study provides the indication of involvement of molecular machinery and various cellular proteins in the biosynthesis of silver nanoparticles. In this report, the study is mainly focused towards understanding the role of diverse cellular protein in the synthesis and capping of silver nanoparticles using C. reinhardtii as a model system.

  1. Full establishment of arbuscular mycorrhizal symbiosis in rice occurs independently of enzymatic jasmonate biosynthesis.

    Science.gov (United States)

    Gutjahr, Caroline; Siegler, Heike; Haga, Ken; Iino, Moritoshi; Paszkowski, Uta

    2015-01-01

    Development of the mutualistic arbuscular mycorrhiza (AM) symbiosis between most land plants and fungi of the Glomeromycota is regulated by phytohormones. The role of jasmonate (JA) in AM colonization has been investigated in the dicotyledons Medicago truncatula, tomato and Nicotiana attenuata and contradicting results have been obtained with respect to a neutral, promotive or inhibitory effect of JA on AM colonization. Furthermore, it is currently unknown whether JA plays a role in AM colonization of monocotyledonous roots. Therefore we examined whether JA biosynthesis is required for AM colonization of the monocot rice. To this end we employed the rice mutant constitutive photomorphogenesis 2 (cpm2), which is deficient in JA biosynthesis. Through a time course experiment the amount and morphology of fungal colonization did not differ between wild-type and cpm2 roots. Furthermore, no significant difference in the expression of AM marker genes was detected between wild type and cpm2. However, treatment of wild-type roots with 50 μM JA lead to a decrease of AM colonization and this was correlated with induction of the defense gene PR4. These results indicate that JA is not required for AM colonization of rice but high levels of JA in the roots suppress AM development likely through the induction of defense.

  2. Full establishment of arbuscular mycorrhizal symbiosis in rice occurs independently of enzymatic jasmonate biosynthesis.

    Directory of Open Access Journals (Sweden)

    Caroline Gutjahr

    Full Text Available Development of the mutualistic arbuscular mycorrhiza (AM symbiosis between most land plants and fungi of the Glomeromycota is regulated by phytohormones. The role of jasmonate (JA in AM colonization has been investigated in the dicotyledons Medicago truncatula, tomato and Nicotiana attenuata and contradicting results have been obtained with respect to a neutral, promotive or inhibitory effect of JA on AM colonization. Furthermore, it is currently unknown whether JA plays a role in AM colonization of monocotyledonous roots. Therefore we examined whether JA biosynthesis is required for AM colonization of the monocot rice. To this end we employed the rice mutant constitutive photomorphogenesis 2 (cpm2, which is deficient in JA biosynthesis. Through a time course experiment the amount and morphology of fungal colonization did not differ between wild-type and cpm2 roots. Furthermore, no significant difference in the expression of AM marker genes was detected between wild type and cpm2. However, treatment of wild-type roots with 50 μM JA lead to a decrease of AM colonization and this was correlated with induction of the defense gene PR4. These results indicate that JA is not required for AM colonization of rice but high levels of JA in the roots suppress AM development likely through the induction of defense.

  3. Monoterpene biosynthesis potential of plant subcellular compartments

    NARCIS (Netherlands)

    Dong, L.; Jongedijk, E.J.; Bouwmeester, H.J.; Krol, van der A.R.

    2016-01-01

    Subcellular monoterpene biosynthesis capacity based on local geranyl diphosphate (GDP) availability or locally boosted GDP production was determined for plastids, cytosol and mitochondria. A geraniol synthase (GES) was targeted to plastids, cytosol, or mitochondria. Transient expression in Nicotiana

  4. Antibacterial Targets in Fatty Acid Biosynthesis

    Science.gov (United States)

    Wright, H. Tonie; Reynolds, Kevin A.

    2008-01-01

    Summary The fatty acid biosynthesis pathway is an attractive but still largely unexploited target for development of new anti-bacterial agents. The extended use of the anti-tuberculosis drug isoniazid and the antiseptic triclosan, which are inhibitors of fatty acid biosynthesis, validates this pathway as a target for anti-bacterial development. Differences in subcellular organization of the bacterial and eukaryotic multi-enzyme fatty acid synthase systems offer the prospect of inhibitors with host vs. target specificity. Platensimycin, platencin, and phomallenic acids, newly discovered natural product inhibitors of the condensation steps in fatty acid biosynthesis, represent new classes of compounds with antibiotic potential. An almost complete catalogue of crystal structures for the enzymes of the type II fatty acid biosynthesis pathway can now be exploited in the rational design of new inhibitors, as well as the recently published crystal structures of type I FAS complexes. PMID:17707686

  5. Lincomycin, cultivation of producing strains and biosynthesis

    Czech Academy of Sciences Publication Activity Database

    Spížek, Jaroslav; Řezanka, Tomáš

    2004-01-01

    Roč. 63, - (2004), s. 510-519 ISSN 0175-7598 Institutional research plan: CEZ:AV0Z5020903 Keywords : lincomycin * cultivation * biosynthesis Subject RIV: EE - Microbiology, Virology Impact factor: 2.358, year: 2004

  6. Control of tylosin biosynthesis in Streptomyces fradiae.

    Science.gov (United States)

    Cundliffe, Eric

    2008-09-01

    Tylosin biosynthesis is controlled in cascade fashion by multiple transcriptional regulators, acting positively or negatively, in conjunction with a signalling ligand that acts as a classical inducer. The roles of regulatory gene products have been characterized by a combination of gene expression analysis and fermentation studies, using engineered strains of S. fradiae in which specific genes were inactivated or overexpressed. Among various novel features of the regulatory model, involvement of the signalling ligand is not essential for tylosin biosynthesis.

  7. Regulation of anthocyanin biosynthesis in peach fruits.

    Science.gov (United States)

    Rahim, Md Abdur; Busatto, Nicola; Trainotti, Livio

    2014-11-01

    MYB10.1 and MYB10.3, with bHLH3, are the likely regulators of anthocyanin biosynthesis in peach fruit. MYB10.1/2/3 forms a cluster on the same genomic fragment where the Anther color ( Ag ) trait is located. Anthocyanins are bioactive compounds responsible for the pigmentation of many plant parts such as leaves, flowers, fruits and roots, and have potential benefits to human health. In peach [Prunus persica (L.) Batsch], peel color is a key determinant for fruit quality and is regulated by flavonoids including anthocyanins. The R2R3 MYB transcription factors (TFs) control the expression of anthocyanin biosynthetic genes with the help of co-activators belonging to the basic-helix-loop-helix (bHLH) and WD40 repeat families. In the peach genome six MYB10-like and three bHLH-like TFs were identified as candidates to be the regulators of the anthocyanin accumulation, which, in yellow flesh fruits, is highest in the peel, abundant in the part of the mesocarp surrounding the stone and lowest in the mesocarp. The expression of MYB10.1 and MYB10.3 correlates with anthocyanin levels of different peach parts. They also have positive correlation with the expression of key structural genes of the anthocyanin pathway, such as CHS, F3H, and UFGT. Functions of peach MYB10s were tested in tobacco and shown to activate key genes in the anthocyanin pathway when bHLHs were co-expressed as partners. Overexpression of MYB10.1/bHLH3 and MYB10.3/bHLH3 activated anthocyanin production by up-regulating NtCHS, NtDFR and NtUFGT while other combinations were not, or much less, effective. As three MYB10 genes are localized in a genomic region where the Ag trait, responsible for anther pigmentation, is localized, it is proposed they are key determinant to introduce new peach cultivars with higher antioxidant level and pigmented fruit.

  8. Inequality indicators and distinguishability in economics

    Science.gov (United States)

    Rosenblatt, J.; Martinás, K.

    2008-03-01

    Money has a material counterpart, such as banknotes or coins, and an ideal expression, monetary units. In the latter case, it is boson-like: individual incomes have no a priori limit, and their units are not distinguishable from each other in economic processes. Individuals, on the other hand, usually occupy one job at a time which makes them akin to fermions. We apply to individual incomes down-to-earth statistical calculations, similar to those for quantum particles, and obtain expressions for the cumulative distribution function, probability density and Lorenz function resulting from the simultaneous use of both statistics. They provide extremely good fits to corresponding data on French income distributions. On this basis, we propose a new entropic inequality indicator.

  9. Generalized coherence concurrence and path distinguishability

    International Nuclear Information System (INIS)

    Chin, Seungbeom

    2017-01-01

    We propose a new family of coherence monotones, named the generalized coherence concurrence (or coherence k -concurrence), which is an analogous concept to the generalized entanglement concurrence. The coherence k -concurrence of a state is nonzero if and only if the coherence number (a recently introduced discrete coherence monotone) of the state is not smaller than k , and a state can be converted to a state with nonzero entanglement k -concurrence via incoherent operations if and only if the state has nonzero coherence k -concurrence. We apply the coherence concurrence family to the problem of wave-particle duality in multi-path interference phenomena. We obtain a sharper equation for path distinguishability (which witnesses the duality) than the known one and show that the amount of each concurrence for the quanton state determines the number of slits which are identified unambiguously. (paper)

  10. Generalized coherence concurrence and path distinguishability

    Science.gov (United States)

    Chin, Seungbeom

    2017-11-01

    We propose a new family of coherence monotones, named the generalized coherence concurrence (or coherence k-concurrence), which is an analogous concept to the generalized entanglement concurrence. The coherence k-concurrence of a state is nonzero if and only if the coherence number (a recently introduced discrete coherence monotone) of the state is not smaller than k, and a state can be converted to a state with nonzero entanglement k-concurrence via incoherent operations if and only if the state has nonzero coherence k-concurrence. We apply the coherence concurrence family to the problem of wave-particle duality in multi-path interference phenomena. We obtain a sharper equation for path distinguishability (which witnesses the duality) than the known one and show that the amount of each concurrence for the quanton state determines the number of slits which are identified unambiguously.

  11. Distinguishing the communicative functions of gestures

    DEFF Research Database (Denmark)

    Jokinen, Kristiina; Navarretta, Costanza; Paggio, Patrizia

    2008-01-01

    This paper deals with the results of a machine learning experiment conducted on annotated gesture data from two case studies (Danish and Estonian). The data concern mainly facial displays, that are annotated with attributes relating to shape and dynamics, as well as communicative function. The re....... The results of the experiments show that the granularity of the attributes used seems appropriate for the task of distinguishing the desired communicative functions. This is a promising result in view of a future automation of the annotation task.......This paper deals with the results of a machine learning experiment conducted on annotated gesture data from two case studies (Danish and Estonian). The data concern mainly facial displays, that are annotated with attributes relating to shape and dynamics, as well as communicative function...

  12. Biosynthesis of antibiotic chuangxinmycin from Actinoplanes tsinanensis

    Directory of Open Access Journals (Sweden)

    Yuanyuan Shi

    2018-03-01

    Full Text Available Chuangxinmycin is an antibiotic isolated from Actinoplanes tsinanensis CPCC 200056 in the 1970s with a novel indole-dihydrothiopyran heterocyclic skeleton. Chuangxinmycin showed in vitro antibacterial activity and in vivo efficacy in mouse infection models as well as preliminary clinical trials. But the biosynthetic pathway of chuangxinmycin has been obscure since its discovery. Herein, we report the identification of a stretch of DNA from the genome of A. tsinanensis CPCC 200056 that encodes genes for biosynthesis of chuangxinmycin by bioinformatics analysis. The designated cxn cluster was then confirmed to be responsible for chuangxinmycin biosynthesis by direct cloning and heterologous expressing in Streptomyces coelicolor M1146. The cytochrome P450 CxnD was verified to be involved in the dihydrothiopyran ring closure reaction by the identification of seco-chuangxinmycin in S. coelicolor M1146 harboring the cxn gene cluster with an inactivated cxnD. Based on these results, a plausible biosynthetic pathway for chuangxinmycin biosynthesis was proposed, by hijacking the primary sulfur transfer system for sulfur incorporation. The identification of the biosynthetic gene cluster of chuangxinmycin paves the way for elucidating the detail biochemical machinery for chuangxinmycin biosynthesis, and provides the basis for the generation of novel chuangxinmycin derivatives by means of combinatorial biosynthesis and synthetic biology. KEY WORDS: Chuangxinmycin, Actinoplanes tsinanensis, Biosynthesis gene cluster, Heterologous expression, Cytochrome P450, Seco-chuangxinmycin, C–S bond formation, Sulfur incorporation

  13. Comparing root architectural models

    Science.gov (United States)

    Schnepf, Andrea; Javaux, Mathieu; Vanderborght, Jan

    2017-04-01

    Plant roots play an important role in several soil processes (Gregory 2006). Root architecture development determines the sites in soil where roots provide input of carbon and energy and take up water and solutes. However, root architecture is difficult to determine experimentally when grown in opaque soil. Thus, root architectural models have been widely used and been further developed into functional-structural models that are able to simulate the fate of water and solutes in the soil-root system (Dunbabin et al. 2013). Still, a systematic comparison of the different root architectural models is missing. In this work, we focus on discrete root architecture models where roots are described by connected line segments. These models differ (a) in their model concepts, such as the description of distance between branches based on a prescribed distance (inter-nodal distance) or based on a prescribed time interval. Furthermore, these models differ (b) in the implementation of the same concept, such as the time step size, the spatial discretization along the root axes or the way stochasticity of parameters such as root growth direction, growth rate, branch spacing, branching angles are treated. Based on the example of two such different root models, the root growth module of R-SWMS and RootBox, we show the impact of these differences on simulated root architecture and aggregated information computed from this detailed simulation results, taking into account the stochastic nature of those models. References Dunbabin, V.M., Postma, J.A., Schnepf, A., Pagès, L., Javaux, M., Wu, L., Leitner, D., Chen, Y.L., Rengel, Z., Diggle, A.J. Modelling root-soil interactions using three-dimensional models of root growth, architecture and function (2013) Plant and Soil, 372 (1-2), pp. 93 - 124. Gregory (2006) Roots, rhizosphere and soil: the route to a better understanding of soil science? European Journal of Soil Science 57: 2-12.

  14. Genomic survey of bZIP transcription factor genes related to tanshinone biosynthesis in Salvia miltiorrhiza

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2018-03-01

    Full Text Available Tanshinones are a class of bioactive components in the traditional Chinese medicine Salvia miltiorrhiza, and their biosynthesis and regulation have been widely studied. Current studies show that basic leucine zipper (bZIP proteins regulate plant secondary metabolism, growth and developmental processes. However, the bZIP transcription factors involved in tanshinone biosynthesis are unknown. Here, we conducted the first genome-wide survey of the bZIP gene family and analyzed the phylogeny, gene structure, additional conserved motifs and alternative splicing events in S. miltiorrhiza. A total of 70 SmbZIP transcription factors were identified and categorized into 11 subgroups based on their phylogenetic relationships with those in Arabidopsis. Moreover, seventeen SmbZIP genes underwent alternative splicing events. According to the transcriptomic data, the SmbZIP genes that were highly expressed in the Danshen root and periderm were selected. Based on the prediction of bZIP binding sites in the promoters and the co-expression analysis and co-induction patterns in response to Ag+ treatment via quantitative real-time polymerase chain reaction (qRT-PCR, we concluded that SmbZIP7 and SmbZIP20 potentially participate in the regulation of tanshinone biosynthesis. These results provide a foundation for further functional characterization of the candidate SmbZIP genes, which have the potential to increase tanshinone production. KEY WORDS: bZIP genes, Salvia miltiorrhiza, Phylogenetic analysis, Expression pattern analysis, Tanshinone biosynthesis

  15. A comparative study of proteomic differences between pencil and storage roots of sweetpotato (Ipomoea batatas (L.) Lam.).

    Science.gov (United States)

    Lee, Jeung Joo; Kim, Yun-Hee; Kwak, Youn-Sig; An, Jae Young; Kim, Pil Joo; Lee, Byung Hyun; Kumar, Vikranth; Park, Kee Woong; Chang, Eun Sil; Jeong, Jae Cheol; Lee, Haeng-Soon; Kwak, Sang-Soo

    2015-02-01

    Fibrous roots of sweetpotato (Ipomoea batatas (L.) Lam.) usually develop into both pencil and storage roots. To understand protein function in root development, a proteomic analysis was conducted on the pencil and storage roots of the light orange-fleshed sweetpotato cultivar, Yulmi. Two-dimensional gel electrophoresis showed that expression of 30 protein spots differed between pencil and storage roots: 15 proteins were up-regulated or expressed in pencil roots and 15 in storage roots. Differentially expressed proteins spots were investigated using matrix-assisted laser desorption/ionization time of flight mass spectrometry, and 10 proteins from pencil roots were identified as binding protein isoform A, catechol oxidase, peroxidases, ascorbate peroxidase, endochitinase, flavanone 3-hydroxylase and unknown proteins. Of the proteins up-regulated in, or restricted to, storage roots, 13 proteins were identified as protein disulfide isomerase, anionic peroxidase, putative ripening protein, sporamin B, sporamin A and sporamin A precursor. An analysis of enzyme activity revealed that catechol oxidase and peroxidase as the first and last enzymes of the lignin biosynthesis pathway, and ascorbate peroxidase had higher activities in pencil than in storage roots. The total concentration of phenolic compounds was also far higher in pencil than in storage roots, and lignin accumulated only in pencil roots. These results provide important insight into sweetpotato proteomics, and imply that lignin biosynthesis and stress-related proteins are up-regulated or uniquely expressed in pencil roots. The results indicate that the reduction of carbon flow toward phenylpropanoid biosynthesis and its delivery to carbohydrate metabolism is a major event in storage root formation. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  16. Silicon promotes cytokinin biosynthesis and delays senescence in Arabidopsis and Sorghum.

    Science.gov (United States)

    Markovich, Oshry; Steiner, Evyatar; Kouřil, Štěpán; Tarkowski, Petr; Aharoni, Asaph; Elbaum, Rivka

    2017-07-01

    Silicate minerals are dominant soil components. Thus, plant roots are constantly exposed to silicic acid. High silicon intake, enabled by root silicon transporters, correlates with increased tolerance to many biotic and abiotic stresses. However, the underlying protection mechanisms are largely unknown. Here, we tested the hypothesis that silicon interacts with the plant hormones, and specifically, that silicic acid intake increases cytokinin biosynthesis. The reaction of sorghum (Sorghum bicolor) and Arabidopsis plants, modified to absorb high versus low amounts of silicon, to dark-induced senescence was monitored, by quantifying expression levels of genes along the senescence pathway and measuring tissue cytokinin levels. In both species, detached leaves with high silicon content senesced more slowly than leaves that were not exposed to silicic acid. Expression levels of genes along the senescence pathway suggested increased cytokinin biosynthesis with silicon exposure. Mass spectrometry measurements of cytokinin suggested a positive correlation between silicon exposure and active cytokinin concentrations. Our results indicate a similar reaction to silicon treatment in distantly related plants, proposing a general function of silicon as a stress reliever, acting via increased cytokinin biosynthesis. © 2017 John Wiley & Sons Ltd.

  17. Ethylene Inhibits Root Elongation during Alkaline Stress through AUXIN1 and Associated Changes in Auxin Accumulation1

    Science.gov (United States)

    Li, Juan; Xu, Heng-Hao; Liu, Wen-Cheng; Zhang, Xiao-Wei

    2015-01-01

    Soil alkalinity causes major reductions in yield and quality of crops worldwide. The plant root is the first organ sensing soil alkalinity, which results in shorter primary roots. However, the mechanism underlying alkaline stress-mediated inhibition of root elongation remains to be further elucidated. Here, we report that alkaline conditions inhibit primary root elongation of Arabidopsis (Arabidopsis thaliana) seedlings by reducing cell division potential in the meristem zones and that ethylene signaling affects this process. The ethylene perception antagonist silver (Ag+) alleviated the inhibition of root elongation by alkaline stress. Moreover, the ethylene signaling mutants ethylene response1-3 (etr1-3), ethylene insensitive2 (ein2), and ein3-1 showed less reduction in root length under alkaline conditions, indicating a reduced sensitivity to alkalinity. Ethylene biosynthesis also was found to play a role in alkaline stress-mediated root inhibition; the ethylene overproducer1-1 mutant, which overproduces ethylene because of increased stability of 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASE5, was hypersensitive to alkaline stress. In addition, the ethylene biosynthesis inhibitor cobalt (Co2+) suppressed alkaline stress-mediated inhibition of root elongation. We further found that alkaline stress caused an increase in auxin levels by promoting expression of auxin biosynthesis-related genes, but the increase in auxin levels was reduced in the roots of the etr1-3 and ein3-1 mutants and in Ag+/Co2+-treated wild-type plants. Additional genetic and physiological data showed that AUXIN1 (AUX1) was involved in alkaline stress-mediated inhibition of root elongation. Taken together, our results reveal that ethylene modulates alkaline stress-mediated inhibition of root growth by increasing auxin accumulation by stimulating the expression of AUX1 and auxin biosynthesis-related genes. PMID:26109425

  18. Genetic Transformation and Hairy Root Induction Enhance the Antioxidant Potential of Lactuca serriola L.

    Directory of Open Access Journals (Sweden)

    Mohamed A. El-Esawi

    2017-01-01

    Full Text Available Lactuca serriola L. is a herbaceous species, used for human nutrition and medicinal purposes. The high antioxidant capacity of L. serriola indicates the possibility of enhancing its edible and health potential by increasing the flavonoid and phenolic contents. The present study aimed at enhancing the production of phenolics and flavonoids by hairy root cultures in Lactuca serriola transformed with Agrobacterium rhizogenes strain AR15834 harbouring the rolB gene. The genetic transformation of rolB in transformed roots was validated, and rolB expression level was evaluated using real-time qPCR analysis. Expression levels of flavonoid biosynthesis genes (CHI, PAL, FLS, and CHS were assessed in the hairy and nontransformed roots. Results showed higher expression levels in the transgenic roots than in the nontransformed ones (p<0.01. Transgenic hairy roots exhibited a 54.8–96.7% increase in the total phenolic content, 38.1–76.2% increase in the total flavonoid content, and 56.7–96.7% increase in the total reducing power when compared with the nontransgenic roots (p<0.01. DPPH results also revealed that the transgenic hairy roots exhibited a 31.6–50% increase in antioxidant potential, when compared to normal roots. This study addressed the enhancement of secondary metabolite biosynthesis by hairy root induction in L. serriola.

  19. Deep sequencing reveals transcriptome re-programming of Polygonum multiflorum thunb. roots to the elicitation with methyl jasmonate.

    Science.gov (United States)

    Liu, Hongchang; Wu, Wei; Hou, Kai; Chen, Junwen; Zhao, Zhi

    2016-02-01

    The phytohormone methyl jasmonate (MeJA) has been successfully used as an effective elicitor to enhance production of stilbenoid which is induced in plants as a secondary metabolite possibly in defense against herbivores and pathogens. However, the mechanism of MeJA-mediated stilbenoid biosynthesis remains unclear. Genomic information for Polygonum multiflorum Thunb. (P. multiflorum) is currently unavailable. To obtain insight into the global regulation mechanism of MeJA in the steady state of stilbene glucoside production (26 h after MeJA elicitation), especially on stilbene glucoside biosynthesis, we sequenced the transcriptomes of MeJA-treated and untreated P. multiflorum roots and obtained more than 51 million clean reads, from which 79,565 unigenes were obtained by de novo assembly. 56,972 unigenes were annotated against databases including Nr, Nt, Swiss-Prot, KEGG and COG. 18,677 genes expressed differentially between untreated and treated roots. Expression level analysis indicated that a large number of genes were associated with plant-pathogen interaction, plant hormone signal transduction, stilbenoid backbone biosynthesis, and phenylpropanoid biosynthesis. 15 known genes involved in the biosynthesis of stilbenoid backbone were found with 7 genes showing increased transcript abundance following elicitation of MeJA. The significantly up (down)-regulated changes of 70 genes in stilbenoid biosynthesis were validated by qRT-PCR assays and PCR product sequencing. According to the expression changes and the previously proposed enzyme functions, multiple candidates for the unknown steps in stilbene glucoside biosynthesis were identified. We also found some genes putatively involved in the transcription factors. This comprehensive description of gene expression information could greatly facilitate our understanding of the molecular mechanisms of MeJA-mediated stilbenoid biosynthesis in P. multiflorum roots. Our results shed new light on the global regulation

  20. Rapid Methods to Distinguish Heterodera schachtii from Heterodera glycines Using PCR Technique

    Directory of Open Access Journals (Sweden)

    Hyoung Rai Ko

    2017-09-01

    Full Text Available The purpose of this study was to develop rapid methods for distinguishing between Heterodera schachtii and H. glycines detected from chinese cabbage fields of highland in Gangwon, Korea. To do this, we performed PCR-RFLP and PCR with the primers set developed in this study for GC147, GC408 and PM001 population, H. schachtii, and YS224, DA142 and BC115 population, H. glycines. Eight restriction enzymes generated RFLP profiles of mtDNA COI region for populations of H. schachtii and H. glycines, repectively. As a result, treatment of two restriction enzymes, RsaI and HinfI, were allowed to distinguish H. schachtii from H. glycines based on the differences of DNA band patterns. The primer set, #JBS1, #JBG1 and #JB3R, amplified specific fragments with 277 and 339 bp of H. schachtii, 339 bp of H. glycines, respectively, while it did not amplify fragments from three root-knot nematodes and two root-lesion nematodes. Thus, the primer set developed in this study could be a good method, which is used to distinguish between H. schachtii and H. glycines.

  1. Metabolic transition in mycorrhizal tomato roots

    Directory of Open Access Journals (Sweden)

    Javier eRivero

    2015-06-01

    Full Text Available Beneficial plant-microorganism interactions are widespread in nature. Among them, the symbiosis between plant roots and arbuscular mycorrhizal fungi is of major importance, commonly improving host nutrition and tolerance against environmental and biotic challenges. This manuscript addresses the main metabolic changes that take place in a well established symbiosis between tomato and two common arbuscular mycorrhizal fungi: Rhizophagus irregularis and Funneliformis mosseae. Principal component analysis of metabolites, determined by non-targeted liquid chromatography-mass spectrometry analysis, showed a strong metabolic rearrangement in mycorrhizal roots. There was generally a negative impact of mycorrhizal symbiosis on amino-acid content, mainly on those involved in phenylpropanoids biosynthesis. On the other hand, clusters of compounds, which accumulate more in the mycorrhizal roots than in the non-mycorrhizal roots, contain many intermediaries in amino-acid and sugar metabolism and the oxylipin pathway. The metabolic reprogramming also affected other pathways from the secondary metabolism, mainly phenyl alcohols (lignins and lignans and vitamins. The results showed that source metabolites of these pathways decreased in mycorrhizal roots, whilst the products derived from -linolenic and amino acids presented higher concentrations in AMF-colonized roots. Mycorrhization, therefore, increased the flux into those pathways. Venn-diagram analysis showed that there are many induced signals shared by both mycorrhizal interactions, pointing to general mycorrhiza-associated changes in the tomato metabolome. Moreover, fungus-specific fingerprints were also found, suggesting that specific molecular alterations may underlie the reported functional diversity of the symbiosis. Since most positively regulated pathways were related to stress response mechanisms, their potential contribution to improved host stress tolerance is discussed.

  2. Dehydrocostus lactone is exuded from sunflower roots and stimulates germination of the root parasite Orobanche cumana.

    Science.gov (United States)

    Joel, Daniel M; Chaudhuri, Swapan K; Plakhine, Dina; Ziadna, Hammam; Steffens, John C

    2011-05-01

    The germination of the obligate root parasites of the Orobanchaceae depends on the perception of chemical stimuli from host roots. Several compounds, collectively termed strigolactones, stimulate the germination of the various Orobanche species, but do not significantly elicit germination of Orobanche cumana, a specific parasite of sunflower. Phosphate starvation markedly decreased the stimulatory activity of sunflower root exudates toward O. cumana, and fluridone - an inhibitor of the carotenoid biosynthesis pathway - did not inhibit the production of the germination stimulant in both shoots and roots of young sunflower plants, indicating that the stimulant is not a strigolactone. We identified the natural germination stimulant from sunflower root exudates by bioassay-driven purification. Its chemical structure was elucidated as the guaianolide sesquiterpene lactone dehydrocostus lactone (DCL). Low DCL concentrations effectively stimulate the germination of O. cumana seeds but not of Phelipanche aegyptiaca (syn. Orobanche aegyptiaca). DCL and other sesquiterpene lactones were found in various plant organs, but were previously not known to be exuded to the rhizosphere where they can interact with other organisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Griseorhodins D-F, neuroactive intermediates and end products of post-PKS tailoring modification in Griseorhodin biosynthesis.

    Science.gov (United States)

    Lin, Zhenjian; Zachariah, Malcolm M; Marett, Lenny; Hughen, Ronald W; Teichert, Russell W; Concepcion, Gisela P; Haygood, Margo G; Olivera, Baldomero M; Light, Alan R; Schmidt, Eric W

    2014-05-23

    The griseorhodins belong to a family of extensively modified aromatic polyketides that exhibit activities such as inhibition of HIV reverse transcriptase and human telomerase. The vast structural diversity of this group of polyketides is largely introduced by enzymatic oxidations, which can significantly influence the bioactivity profile. Four new compounds, griseorhodins D-F, were isolated from a griseorhodin producer, Streptomyces sp. CN48+, based upon their enhancement of calcium uptake in a mouse dorsal root ganglion primary cell culture assay. Two of these compounds, griseorhodins D1 and D2, were shown to be identical to the major, previously uncharacterized products of a grhM mutant in an earlier griseorhodin biosynthesis study. Their structures enabled the establishment of a more complete hypothesis for the biosynthesis of griseorhodins and related compounds. The other two compounds, griseorhodins E and F, represent new products of post-polyketide synthase tailoring in griseorhodin biosynthesis and showed significant binding activity in a human dopamine active transporter assay.

  4. Relationships between root diameter, root length and root branching along lateral roots in adult, field-grown maize

    OpenAIRE

    Wu, Qian; Pag?s, Lo?c; Wu, Jie

    2016-01-01

    Background and Aims Root diameter, especially apical diameter, plays an important role in root development and function. The variation in diameter between roots, and along roots, affects root structure and thus the root system?s overall foraging performance. However, the effect of diameter variation on root elongation, branching and topological connections has not been examined systematically in a population of high-order roots, nor along the roots, especially for mature plants grown in the f...

  5. Tooth Eruption without Roots

    OpenAIRE

    Wang, X.-P.

    2013-01-01

    Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the diffic...

  6. Integration of Transcriptome, Proteome and Metabolism Data Reveals the Alkaloids Biosynthesis in Macleaya cordata and Macleaya microcarpa

    Science.gov (United States)

    Liu, Fuqing; Huang, Peng; Zhu, Pengcheng; Chen, Jinjun; Shi, Mingming; Guo, Fang; Cheng, Pi; Zeng, Jing; Liao, Yifang; Gong, Jing; Zhang, Hong-Mei; Wang, Depeng; Guo, An-Yuan; Xiong, Xingyao

    2013-01-01

    Background The Macleaya spp., including Macleaya cordata and Macleaya microcarpa, are traditional anti-virus, inflammation eliminating, and insecticide herb medicines for their isoquinoline alkaloids. They are also known as the basis of the popular natural animal food addictive in Europe. However, few studies especially at genomics level were conducted on them. Hence, we performed the Macleaya spp. transcriptome and integrated it with iTRAQ proteome analysis in order to identify potential genes involved in alkaloids biosynthesis. Methodology and Principal Findings We elaborately designed the transcriptome, proteome and metabolism profiling for 10 samples of both species to explore their alkaloids biosynthesis. From the transcriptome data, we obtained 69367 and 78255 unigenes for M. cordata and M. microcarpa, in which about two thirds of them were similar to sequences in public databases. By metabolism profiling, reverse patterns for alkaloids sanguinarine, chelerythrine, protopine, and allocryptopine were observed in different organs of two species. We characterized the expressions of enzymes in alkaloid biosynthesis pathways. We also identified more than 1000 proteins from iTRAQ proteome data. Our results strongly suggest that the root maybe the organ for major alkaloids biosynthesis of Macleaya spp. Except for biosynthesis, the alkaloids storage and transport were also important for their accumulation. The ultrastructure of laticifers by SEM helps us to prove the alkaloids maybe accumulated in the mature roots. Conclusions/Significance To our knowledge this is the first study to elucidate the genetic makeup of Macleaya spp. This work provides clues to the identification of the potential modulate genes involved in alkaloids biosynthesis in Macleaya spp., and sheds light on researches for non-model medicinal plants by integrating different high-throughput technologies. PMID:23326424

  7. Distinguishing modified gravity from dark energy

    International Nuclear Information System (INIS)

    Bertschinger, Edmund; Zukin, Phillip

    2008-01-01

    The acceleration of the Universe can be explained either through dark energy or through the modification of gravity on large scales. In this paper we investigate modified gravity models and compare their observable predictions with dark energy models. Modifications of general relativity are expected to be scale independent on superhorizon scales and scale dependent on subhorizon scales. For scale-independent modifications, utilizing the conservation of the curvature scalar and a parametrized post-Newtonian formulation of cosmological perturbations, we derive results for large-scale structure growth, weak gravitational lensing, and cosmic microwave background anisotropy. For scale-dependent modifications, inspired by recent f(R) theories we introduce a parametrization for the gravitational coupling G and the post-Newtonian parameter γ. These parametrizations provide a convenient formalism for testing general relativity. However, we find that if dark energy is generalized to include both entropy and shear stress perturbations, and the dynamics of dark energy is unknown a priori, then modified gravity cannot in general be distinguished from dark energy using cosmological linear perturbations.

  8. Distinguishing psychological characteristics of expert cricket batsmen.

    Science.gov (United States)

    Weissensteiner, Juanita R; Abernethy, Bruce; Farrow, Damian; Gross, John

    2012-01-01

    This paper sought to determine the psychological characteristics and skills that are fundamental to batting success in the sport of cricket. Following on from the findings of an earlier qualitative investigation which suggested that a favourable mix of psychological attributes and skills are critical to high performance in batting (Weissensteiner et al.(10)), adult-aged batsmen of two different skill levels (highly skilled n=11; lesser skilled n=10) completed a battery of psychological tests that included measures of mental toughness (Mental Toughness Inventory), perfectionism (Multidimensional Perfectionism Scale), coping ability (Athletic Coping Skills Inventory-28), and optimism (Attributional Styles Questionnaire). Contrary to the research hypothesis, it was found that the highly skilled batsmen were only distinguishable from batsmen of lesser skill by their higher degree of global mental toughness. The skilled batsmen scored significantly higher on mental toughness dimensions relating to motivation (Personal Bests, Task Value and Commitment), coping skill (Perseverance) and self-belief (Potential). If mental toughness can be reliably predicted at an earlier age, it may be an attribute worthy of inclusion in future talent identification and development programs. Copyright © 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  9. Regulation of anthocyanin and proanthocyanidin biosynthesis by Medicago truncatula bHLH transcription factor MtTT8.

    Science.gov (United States)

    Li, Penghui; Chen, Beibei; Zhang, Gaoyang; Chen, Longxiang; Dong, Qiang; Wen, Jiangqi; Mysore, Kirankumar S; Zhao, Jian

    2016-05-01

    The MYB- basic helix-loop-helix (bHLH)-WD40 complexes regulating anthocyanin and proanthocyanidin (PA) biosynthesis in plants are not fully understood. Here Medicago truncatula bHLH MtTT8 was characterized as a central component of these ternary complexes that control anthocyanin and PA biosynthesis. Mttt8 mutant seeds have a transparent testa phenotype with reduced PAs and anthocyanins. MtTT8 restores PA and anthocyanin productions in Arabidopsis tt8 mutant. Ectopic expression of MtTT8 restores anthocyanins and PAs in mttt8 plant and hairy roots and further enhances both productions in wild-type hairy roots. Transcriptomic analyses and metabolite profiling of mttt8 mutant seeds and M. truncatula hairy roots (mttt8 mutant, mttt8 mutant complemented with MtTT8, or MtTT8 overexpression lines) indicate that MtTT8 regulates a subset of genes involved in PA and anthocyanin biosynthesis. MtTT8 is genetically regulated by MtLAP1, MtPAR and MtWD40-1. Combinations of MtPAR, MtLAP1, MtTT8 and MtWD40-1 activate MtTT8 promoter in yeast assay. MtTT8 interacts with these transcription factors to form regulatory complexes. MtTT8, MtWD40-1 and an MYB factor, MtPAR or MtLAP1, interacted and activated promoters of anthocyanidin reductase and anthocyanidin synthase to regulate PA and anthocyanin biosynthesis, respectively. Our results provide new insights into the complex regulation of PA and anthocyanin biosynthesis in M. truncatula. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  10. Root production method system

    Science.gov (United States)

    Wayne Lovelace

    2002-01-01

    The RPM system (Root Production Method) is a multistep production system of container tree production that places primary emphasis on the root system because the root system ultimately determines the tree's survival and performance in its outplanted environment. This particular container production system has been developed to facilitate volume production, in a...

  11. Armillaria root rot

    Science.gov (United States)

    First described on grapevines in California in the 1880s, Armillaria root rot occurs in all major grape-growing regions of the state. The causal fungus, Armillaria mellea, infects woody grapevine roots and the base of the trunk (the root collar), resulting in a slow decline and eventual death of the...

  12. Root canal irrigation

    NARCIS (Netherlands)

    van der Sluis, L.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, L.E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root

  13. The Root Canal Biofilm

    NARCIS (Netherlands)

    van der Sluis, L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, Michel; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root

  14. Integral and Multidimensional Linear Distinguishers with Correlation Zero

    DEFF Research Database (Denmark)

    Bogdanov, Andrey; Leander, Gregor; Nyberg, Kaisa

    2012-01-01

    Zero-correlation cryptanalysis uses linear approximations holding with probability exactly 1/2. In this paper, we reveal fundamental links of zero-correlation distinguishers to integral distinguishers and multidimensional linear distinguishers. We show that an integral implies zero......-correlation linear approximations and that a zero-correlation linear distinguisher is actually a special case of multidimensional linear distinguishers. These observations provide new insight into zero-correlation cryptanalysis which is illustrated by attacking a Skipjack variant and round-reduced CAST-256 without...

  15. LDRD 149045 final report distinguishing documents.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Scott A.

    2010-09-01

    This LDRD 149045 final report describes work that Sandians Scott A. Mitchell, Randall Laviolette, Shawn Martin, Warren Davis, Cindy Philips and Danny Dunlavy performed in 2010. Prof. Afra Zomorodian provided insight. This was a small late-start LDRD. Several other ongoing efforts were leveraged, including the Networks Grand Challenge LDRD, and the Computational Topology CSRF project, and the some of the leveraged work is described here. We proposed a sentence mining technique that exploited both the distribution and the order of parts-of-speech (POS) in sentences in English language documents. The ultimate goal was to be able to discover 'call-to-action' framing documents hidden within a corpus of mostly expository documents, even if the documents were all on the same topic and used the same vocabulary. Using POS was novel. We also took a novel approach to analyzing POS. We used the hypothesis that English follows a dynamical system and the POS are trajectories from one state to another. We analyzed the sequences of POS using support vector machines and the cycles of POS using computational homology. We discovered that the POS were a very weak signal and did not support our hypothesis well. Our original goal appeared to be unobtainable with our original approach. We turned our attention to study an aspect of a more traditional approach to distinguishing documents. Latent Dirichlet Allocation (LDA) turns documents into bags-of-words then into mixture-model points. A distance function is used to cluster groups of points to discover relatedness between documents. We performed a geometric and algebraic analysis of the most popular distance functions and made some significant and surprising discoveries, described in a separate technical report.

  16. Profiling of the Major Phenolic Compounds and Their Biosynthesis Genes in Sophora flavescens Aiton

    Directory of Open Access Journals (Sweden)

    Jeongyeo Lee

    2018-01-01

    Full Text Available Sophorae Radix (Sophora flavescens Aiton has long been used in traditional medicine in East Asia due to the various biological activities of its secondary metabolites. Endogenous contents of phenolic compounds (phenolic acid, flavonol, and isoflavone and the main bioactive compounds of Sophorae Radix were analyzed based on the qualitative HPLC analysis and evaluated in different organs and at different developmental stages. In total, 11 compounds were detected, and the composition of the roots and aerial parts (leaves, stems, and flowers was significantly different. trans-Cinnamic acid and p-coumaric acid were observed only in the aerial parts. Large amounts of rutin and maackiain were detected in the roots. Four phenolic acid compounds (benzoic acid, caffeic acid, ferulic acid, and chlorogenic acid and four flavonol compounds (kaempferol, catechin hydrate, epicatechin, and rutin were higher in aerial parts than in roots. To identify putative genes involved in phenolic compounds biosynthesis, a total of 41 transcripts were investigated. Expression patterns of these selected genes, as well as the multiple isoforms for the genes, varied by organ and developmental stage, implying that they are involved in the biosynthesis of various phenolic compounds both spatially and temporally.

  17. Plant tropane alkaloid biosynthesis evolved independently in the Solanaceae and Erythroxylaceae.

    Science.gov (United States)

    Jirschitzka, Jan; Schmidt, Gregor W; Reichelt, Michael; Schneider, Bernd; Gershenzon, Jonathan; D'Auria, John Charles

    2012-06-26

    The pharmacologically important tropane alkaloids have a scattered distribution among angiosperm families, like many other groups of secondary metabolites. To determine whether tropane alkaloids have evolved repeatedly in different lineages or arise from an ancestral pathway that has been lost in most lines, we investigated the tropinone-reduction step of their biosynthesis. In species of the Solanaceae, which produce compounds such as atropine and scopolamine, this reaction is known to be catalyzed by enzymes of the short-chain dehydrogenase/reductase family. However, in Erythroxylum coca (Erythroxylaceae), which accumulates cocaine and other tropane alkaloids, no proteins of the short-chain dehydrogenase/reductase family were found that could catalyze this reaction. Instead, purification of E. coca tropinone-reduction activity and cloning of the corresponding gene revealed that a protein of the aldo-keto reductase family carries out this reaction in E. coca. This protein, designated methylecgonone reductase, converts methylecgonone to methylecgonine, the penultimate step in cocaine biosynthesis. The protein has highest sequence similarity to other aldo-keto reductases, such as chalcone reductase, an enzyme of flavonoid biosynthesis, and codeinone reductase, an enzyme of morphine alkaloid biosynthesis. Methylecgonone reductase reduces methylecgonone (2-carbomethoxy-3-tropinone) stereospecifically to 2-carbomethoxy-3β-tropine (methylecgonine), and has its highest activity, protein level, and gene transcript level in young, expanding leaves of E. coca. This enzyme is not found at all in root tissues, which are the site of tropane alkaloid biosynthesis in the Solanaceae. This evidence supports the theory that the ability to produce tropane alkaloids has arisen more than once during the evolution of the angiosperms.

  18. The Spatial Organization of Glucosinolate Biosynthesis

    DEFF Research Database (Denmark)

    Nintemann, Sebastian

    between the individual classes of glucosinolates under constitutive and induced conditions and identified the source tissues of these defense compounds. Protein-protein interaction studies were carried out to investigate the subcellular organization of glucosinolate biosynthesis. We identified a family...... resistance and nutritional value and many plant specialized metabolites are of high value due to their health promoting characteristics. Glucosinolates are defense compounds found in many crops from the Brassicaceae family and are of high interest because of their nutritional and antinutritional properties...... cells is an open question. Likewise, it is not known how glucosinolate biosynthesis is orchestrated at the subcellular level. These open questions were addressed with several approaches in this project, with the aim of shedding light on the spatial organization of glucosinolate biosynthesis from...

  19. Functional and Evolutionary Relationship between Arginine Biosynthesis and Prokaryotic Lysine Biosynthesis through α-Aminoadipate

    Science.gov (United States)

    Miyazaki, Junichi; Kobashi, Nobuyuki; Nishiyama, Makoto; Yamane, Hisakazu

    2001-01-01

    Our previous studies revealed that lysine is synthesized through α-aminoadipate in an extremely thermophilic bacterium, Thermus thermophilus HB27. Sequence analysis of a gene cluster involved in the lysine biosynthesis of this microorganism suggested that the conversion from α-aminoadipate to lysine proceeds in a way similar to that of arginine biosynthesis. In the present study, we cloned an argD homolog of T. thermophilus HB27 which was not included in the previously cloned lysine biosynthetic gene cluster and determined the nucleotide sequence. A knockout of the argD-like gene, now termed lysJ, in T. thermophilus HB27 showed that this gene is essential for lysine biosynthesis in this bacterium. The lysJ gene was cloned into a plasmid and overexpressed in Escherichia coli, and the LysJ protein was purified to homogeneity. When the catalytic activity of LysJ was analyzed in a reverse reaction in the putative pathway, LysJ was found to transfer the ɛ-amino group of N2-acetyllysine, a putative intermediate in lysine biosynthesis, to 2-oxoglutarate. When N2-acetylornithine, a substrate for arginine biosynthesis, was used as the substrate for the reaction, LysJ transferred the δ-amino group of N2-acetylornithine to 2-oxoglutarate 16 times more efficiently than when N2-acetyllysine was the amino donor. All these results suggest that lysine biosynthesis in T. thermophilus HB27 is functionally and evolutionarily related to arginine biosynthesis. PMID:11489859

  20. Triterpenoid biosynthesis in Euphorbia lathyris latex

    International Nuclear Information System (INIS)

    Hawkins, D.R.

    1987-11-01

    The structures of triterpenols, not previously been known, from Euphorbia lathyris latex are reported. A method for quantifying very small amounts of these compounds was developed. Concerning the biochemistry of the latex, no exogenous cofactors were required for the biosynthesis and the addition of compounds such as NADPAH and ATP do not stimulate the biosynthesis. The addition of DTE or a similar anti-oxidant was found to help reduce the oxidation of the latex, thus increasing the length of time that the latex remains active. The requirement of a divalent cation and the preference for Mn in the pellet was observed. The effect of several inhibitors on the biosynthesis of the triterpenoids was examined. Mevinolin was found to inhibit the biosynthesis of the triterpenoids from acetate, but not mevalonate. A dixon plot of the inhibition of acetate incorporation showed an I 50 concentration of 3.2 μM. Fenpropimorph was found to have little or no effect on the biosynthesis. Tridemorph was found to inhibit the biosynthesis of all of the triterpenoids with an I 50 of 4 μM. It was also observed that the cyclopropyl containing triterpenols, cycloartenol and 24-methylenecycloartenol were inhibited much more strongly than those containing an 8-9 double bond, lanosterol and 24-methylenelanosterol. The evidence indicates, but does not definetely prove, that lanosterol and 24-methylenelanosterol are not made from cycloartenol and 24-methylenecycloartenol via a ring-opening enzyme such as cycloeucalenol-obtusifoliol isomerase. The possibilty that cycloartenol is made via lanosterol was investigated by synthesizing 4-R-4- 3 H-mevalonic acid and incubating latex with a mixture of this and 14 C-mevalonic acid. From the 3 H/ 14 C ratio it was shown that cycloartenol and 24-methylenecycloartenol are not made via an intermediate containing as 8-9 double bond. 88 refs., 15 figs., 30 tabs

  1. Nucleoside antibiotics: biosynthesis, regulation, and biotechnology.

    Science.gov (United States)

    Niu, Guoqing; Tan, Huarong

    2015-02-01

    The alarming rise in antibiotic-resistant pathogens has coincided with a decline in the supply of new antibiotics. It is therefore of great importance to find and create new antibiotics. Nucleoside antibiotics are a large family of natural products with diverse biological functions. Their biosynthesis is a complex process through multistep enzymatic reactions and is subject to hierarchical regulation. Genetic and biochemical studies of the biosynthetic machinery have provided the basis for pathway engineering and combinatorial biosynthesis to create new or hybrid nucleoside antibiotics. Dissection of regulatory mechanisms is leading to strategies to increase the titer of bioactive nucleoside antibiotics. Copyright © 2014. Published by Elsevier Ltd.

  2. Combinatorial Biosynthesis of Polyketides – A Perspective

    Science.gov (United States)

    Wong, Fong T.; Khosla, Chaitan

    2012-01-01

    Since their discovery, polyketide synthases have been attractive targets of biosynthetic engineering to make “unnatural” natural products. Although combinatorial biosynthesis has made encouraging advances over the past two decades, the field remains in its infancy. In this enzyme-centric perspective, we discuss the scientific and technological challenges that could accelerate the adoption of combinatorial biosynthesis as a method of choice for the preparation of encoded libraries of bioactive small molecules. Borrowing a page from the protein structure prediction community, we propose a periodic challenge program to vet the most promising methods in the field, and to foster the collective development of useful tools and algorithms. PMID:22342766

  3. Method for determining heterologous biosynthesis pathways

    KAUST Repository

    Gao, Xin

    2017-08-10

    The present invention relates to a method and system for dynamically analyzing, determining, predicting and displaying ranked suitable heterologous biosynthesis pathways for a specified host. The present invention addresses the problem of finding suitable pathways for the endogenous metabolism of a host organism because the efficacy of heterologous biosynthesis is affected by competing endogenous pathways. The present invention is called MRE (Metabolic Route Explorer), and it was conceived and developed to systematically and dynamically search for, determine, analyze, and display promising heterologous pathways while considering competing endogenous reactions in a given host organism.

  4. Convergent Evolution of Ergothioneine Biosynthesis in Cyanobacteria.

    Science.gov (United States)

    Liao, Cangsong; Seebeck, Florian P

    2017-11-02

    Biosynthesis of N-α-trimethyl-2-thiohistidine (ergothioneine) is a frequent trait in cyanobacteria. This sulfur compound may provide essential relief from oxidative stress related to oxygenic photosynthesis. The central steps in ergothioneine biosynthesis are catalyzed by a histidine methyltransferase and an iron-dependent sulfoxide synthase. In this report, we present evidence that some cyanobacteria recruited and adapted a sulfoxide synthase from a different biosynthetic pathway to make ergothioneine. The discovery of a second origin of ergothioneine production underscores the physiological importance of this metabolite and highlights the evolutionary malleability of the thiohistidine biosynthetic machinery. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Biosynthesis of silver nanoparticles by Aspergillus niger , Fusarium ...

    African Journals Online (AJOL)

    ... scanning electron microscope (SEM). Results indicate the synthesis of silver nanoparticles in the reaction mixture. The synthesis of nanoparticles would be suitable for developing a microbial nanotechnology biosynthesis process for mass scale production. Keywords: Silver nanoparticles, biosynthesis, fungi, Aspergillus.

  6. Identification of Light-Independent Anthocyanin Biosynthesis Mutants Induced by Ethyl Methane Sulfonate in Turnip "Tsuda" (Brassica rapa).

    Science.gov (United States)

    Yang, Jian-Fei; Chen, Yun-Zhu; Kawabata, Saneyuki; Li, Yu-Hua; Wang, Yu

    2017-06-22

    The epidermis of swollen storage roots in purple cultivars of turnip "Tsuda" ( Brassica rapa ) accumulates anthocyanin in a light-dependent manner, especially in response to UV-A light, of which the mechanism is unclear. In this study, we mutagenized 15,000 seeds by 0.5% ( v / v ) ethyl methane sulfonate (EMS) and obtained 14 mutants with abnormal anthocyanin production in their epidermis of swollen storage roots. These mutants were classified into two groups: the red mutants with constitutive anthocyanin accumulation in their epidermis of storage roots even in underground parts in darkness and the white mutants without anthocyanin accumulation in the epidermis of storage roots in aboveground parts exposed to sunlight. Test cross analysis demonstrated that w9 , w68 , w204 , r15 , r21 , r30 and r57 contained different mutations responsible for their phenotypic variations. Further genetic analysis of four target mutants ( w9 , w68 , w204 and r15 ) indicated that each of them was controlled by a different recessive gene. Intriguingly, the expression profiles of anthocyanin biosynthesis genes, including structural and regulatory genes, coincided with their anthocyanin levels in the epidermis of storage roots in the four target mutants. We proposed that potential genes responsible for the mutations should be upstream factors of the anthocyanin biosynthesis pathway in turnips, which provided resources to further investigate the mechanisms of light-induced anthocyanin accumulation.

  7. Local Auxin Biosynthesis Mediated by a YUCCA Flavin Monooxygenase Regulates Haustorium Development in the Parasitic Plant Phtheirospermum japonicum.

    Science.gov (United States)

    Ishida, Juliane K; Wakatake, Takanori; Yoshida, Satoko; Takebayashi, Yumiko; Kasahara, Hiroyuki; Wafula, Eric; dePamphilis, Claude W; Namba, Shigetou; Shirasu, Ken

    2016-08-01

    Parasitic plants in the Orobanchaceae cause serious agricultural problems worldwide. Parasitic plants develop a multicellular infectious organ called a haustorium after recognition of host-released signals. To understand the molecular events associated with host signal perception and haustorium development, we identified differentially regulated genes expressed during early haustorium development in the facultative parasite Phtheirospermum japonicum using a de novo assembled transcriptome and a customized microarray. Among the genes that were upregulated during early haustorium development, we identified YUC3, which encodes a functional YUCCA (YUC) flavin monooxygenase involved in auxin biosynthesis. YUC3 was specifically expressed in the epidermal cells around the host contact site at an early time point in haustorium formation. The spatio-temporal expression patterns of YUC3 coincided with those of the auxin response marker DR5, suggesting generation of auxin response maxima at the haustorium apex. Roots transformed with YUC3 knockdown constructs formed haustoria less frequently than nontransgenic roots. Moreover, ectopic expression of YUC3 at the root epidermal cells induced the formation of haustorium-like structures in transgenic P. japonicum roots. Our results suggest that expression of the auxin biosynthesis gene YUC3 at the epidermal cells near the contact site plays a pivotal role in haustorium formation in the root parasitic plant P. japonicum. © 2016 American Society of Plant Biologists. All rights reserved.

  8. Local Auxin Biosynthesis Mediated by a YUCCA Flavin Monooxygenase Regulates Haustorium Development in the Parasitic Plant Phtheirospermum japonicum[OPEN

    Science.gov (United States)

    Takebayashi, Yumiko; Kasahara, Hiroyuki; Wafula, Eric; dePamphilis, Claude W.; Namba, Shigetou

    2016-01-01

    Parasitic plants in the Orobanchaceae cause serious agricultural problems worldwide. Parasitic plants develop a multicellular infectious organ called a haustorium after recognition of host-released signals. To understand the molecular events associated with host signal perception and haustorium development, we identified differentially regulated genes expressed during early haustorium development in the facultative parasite Phtheirospermum japonicum using a de novo assembled transcriptome and a customized microarray. Among the genes that were upregulated during early haustorium development, we identified YUC3, which encodes a functional YUCCA (YUC) flavin monooxygenase involved in auxin biosynthesis. YUC3 was specifically expressed in the epidermal cells around the host contact site at an early time point in haustorium formation. The spatio-temporal expression patterns of YUC3 coincided with those of the auxin response marker DR5, suggesting generation of auxin response maxima at the haustorium apex. Roots transformed with YUC3 knockdown constructs formed haustoria less frequently than nontransgenic roots. Moreover, ectopic expression of YUC3 at the root epidermal cells induced the formation of haustorium-like structures in transgenic P. japonicum roots. Our results suggest that expression of the auxin biosynthesis gene YUC3 at the epidermal cells near the contact site plays a pivotal role in haustorium formation in the root parasitic plant P. japonicum. PMID:27385817

  9. Transcriptome and metabolome analysis in shoot and root of Valeriana fauriei.

    Science.gov (United States)

    Park, Yun Ji; Li, Xiaohua; Noh, Seung Jae; Kim, Jae Kwang; Lim, Soon Sung; Park, Nam Il; Kim, Soonok; Kim, Yeon Bok; Kim, Young Ock; Lee, Sang Won; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Park, Sang Un

    2016-04-23

    Valeriana fauriei is commonly used in the treatment of cardiovascular diseases in many countries. Several constituents with various pharmacological properties are present in the roots of Valeriana species. Although many researches on V. fauriei have been done since a long time, further studies in the discipline make a limit due to inadequate genomic information. Hence, Illumina HiSeq 2500 system was conducted to obtain the transcriptome data from shoot and root of V. fauriei. A total of 97,595 unigenes were noticed from 346,771,454 raw reads after preprocessing and assembly. Of these, 47,760 unigens were annotated with Uniprot BLAST hits and mapped to COG, GO and KEGG pathway. Also, 70,013 and 88,827 transcripts were expressed in root and shoot of V. fauriei, respectively. Among the secondary metabolite biosynthesis, terpenoid backbone and phenylpropanoid biosynthesis were large groups, where transcripts was involved. To characterize the molecular basis of terpenoid, carotenoid, and phenylpropanoid biosynthesis, the levels of transcription were determined by qRT-PCR. Also, secondary metabolites content were measured using GC/MS and HPLC analysis for that gene expression correlated with its accumulation respectively between shoot and root of V. fauriei. We have identified the transcriptome using Illumina HiSeq system in shoot and root of V. fauriei. Also, we have demonstrated gene expressions associated with secondary metabolism such as terpenoid, carotenoid, and phenylpropanoid.

  10. Roots: evolutionary origins and biogeochemical significance.

    Science.gov (United States)

    Raven, J A; Edwards, D

    2001-03-01

    Roots, as organs distinguishable developmentally and anatomically from shoots (other than by occurrence of stomata and sporangia on above-ground organs), evolved in the sporophytes of at least two distinct lineages of early vascular plants during their initial major radiation on land in Early Devonian times (c. 410-395 million years ago). This was some 15 million years after the appearance of tracheophytes and c. 50 million years after the earliest embryophytes of presumed bryophyte affinity. Both groups are known initially only from spores, but from comparative anatomy of extant bryophytes and later Lower Devonian fossils it is assumed that, during these times, below-ground structures (if any) other than true roots fulfilled the functions of anchorage and of water and nutrient acquisition, despite lacking an endodermis (as do the roots of extant Lycopodium spp.). By 375 million years ago root-like structures penetrated almost a metre into the substratum, greatly increasing the volume of mineral matter subject to weathering by the higher than atmospheric CO(2) levels generated by plant and microbial respiration in material with restricted diffusive contact with the atmosphere. Chemical weathering consumes CO(2) in converting silicates into bicarbonate and Si(OH)(4). The CO(2) consumed in weathering ultimately came from atmospheric CO(2) via photosynthesis and respiration; this use of CO(2) probably accounts for most of the postulated 10-fold decrease in atmospheric CO(2) from 400-350 million years ago, with significant effects on shoot evolution. Subsequent evolution of roots has yielded much-branched axes down to 40 microm diameter, a lower limit set by long-distance transport constraints. Finer structures involved in the uptake of nutrients of low diffusivity in soil evolved at least 400 million years ago as arbuscular mycorrhizas or as evaginations of "roots" ("root hairs").

  11. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera)

    OpenAIRE

    Kumar Ramesh R.; Reddy Anjaneya Prasanna L.; Subbaiah Chinna J.; Kumar Niranjana A.; Prasad Nagendra H.N.; Bhukya Balakishan

    2011-01-01

    Ashwagandha (Withania somnifera) is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes) and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant) and crude fiber content exhibited strong association among them and ...

  12. Tooth eruption without roots.

    Science.gov (United States)

    Wang, X-P

    2013-03-01

    Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the difficulties in studying late stages of tooth development and tooth movement and the lack of good model systems. Transgenic mice with eruption problems and short or no roots can be used as a powerful model for further deciphering of the cellular, molecular, and genetic mechanisms underlying root formation and tooth eruption. Better understanding of these processes can provide hints on delivering more efficient dental therapies in the future.

  13. Comprehensive transcriptome analysis unravels the existence of crucial genes regulating primary metabolism during adventitious root formation in Petunia hybrida.

    Directory of Open Access Journals (Sweden)

    Amirhossein Ahkami

    Full Text Available To identify specific genes determining the initiation and formation of adventitious roots (AR, a microarray-based transcriptome analysis in the stem base of the cuttings of Petunia hybrida (line W115 was conducted. A microarray carrying 24,816 unique, non-redundant annotated sequences was hybridized to probes derived from different stages of AR formation. After exclusion of wound-responsive and root-regulated genes, 1,354 of them were identified which were significantly and specifically induced during various phases of AR formation. Based on a recent physiological model distinguishing three metabolic phases in AR formation, the present paper focuses on the response of genes related to particular metabolic pathways. Key genes involved in primary carbohydrate metabolism such as those mediating apoplastic sucrose unloading were induced at the early sink establishment phase of AR formation. Transcriptome changes also pointed to a possible role of trehalose metabolism and SnRK1 (sucrose non-fermenting 1- related protein kinase in sugar sensing during this early step of AR formation. Symplastic sucrose unloading and nucleotide biosynthesis were the major processes induced during the later recovery and maintenance phases. Moreover, transcripts involved in peroxisomal beta-oxidation were up-regulated during different phases of AR formation. In addition to metabolic pathways, the analysis revealed the activation of cell division at the two later phases and in particular the induction of G1-specific genes in the maintenance phase. Furthermore, results point towards a specific demand for certain mineral nutrients starting in the recovery phase.

  14. Conjoined lumbosacral nerve roots

    Directory of Open Access Journals (Sweden)

    Atila Yılmaz

    2012-03-01

    Full Text Available Lumbosacral nerve root anomalies are a rare group ofcongenital anatomical anomalies. Various types of anomaliesof the lumbosacral nerve roots have been documentedin the available international literature. Ttheseanomalies may consist of a bifid, conjoined structure, ofa transverse course or of a characteristic anastomizedappearance. Firstly described as an incidental findingduring autopsies or surgical procedures performed forlumbar disk herniations and often asymptomatic, lumbosacralnerve root anomalies have been more frequentlydescribed in the last years due to the advances made inradiological diagnosis.

  15. Biosynthesis and metabolic pathways of pivalic acid

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Kolouchová, I.; Čejková, A.; Sigler, Karel

    2012-01-01

    Roč. 95, č. 6 (2012), s. 1371-1376 ISSN 0175-7598 R&D Projects: GA ČR(CZ) GAP503/11/0215 Institutional support: RVO:61388971 Keywords : Pivalic acid * Isooctane * Biosynthesis Subject RIV: EE - Microbiology, Virology Impact factor: 3.689, year: 2012

  16. Combinatorial biosynthesis of medicinal plant secondary metabolites

    NARCIS (Netherlands)

    Julsing, Mattijs K.; Koulman, Albert; Woerdenbag, Herman J.; Quax, Wim J.; Kayser, Oliver

    2006-01-01

    Combinatorial biosynthesis is a new tool in the generation of novel natural products and for the production of rare and expensive natural products. The basic concept is combining metabolic pathways in different organisms on a genetic level. As a consequence heterologous organisms provide precursors

  17. Biosynthesis of silver nanoparticles synthesized by Aspergillus

    Indian Academy of Sciences (India)

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour ...

  18. Bile acid biosynthesis and its regulation

    Directory of Open Access Journals (Sweden)

    Areta Hebanowska

    2010-10-01

    Full Text Available Bile acid biosynthesis is the main pathway of cholesterol catabolism. Bile acids are more soluble than cholesterol so are easier to excrete. As amphipathic molecules they participate in lipid digestion and absorption in the intestine and they help to excrete free cholesterol with bile. They are also ligands for nuclear receptors regulating the expression of genes involved in cholesterol metabolism. Interconversion of cholesterol into bile acids is an important point of its homeostasis. Seventeen enzymes are engaged in this process and many of them are cytochromes P450. Bile acid synthesis initiation may proceed with the “classical” pathway (starting with cholesterol hydroxylation at the C7α position or the “alternative” pathway (starting with cholesterol hydroxylation at the C27 position. Two additional pathways are possible, though their quantitative significance is small (initiated with cholesterol hydroxylations of C24 and C25 positions. Oxysterols produced are not only intermediates of bile acid biosynthesis but also important regulators of metabolism. Bile acid biosynthesis takes place in the liver, but some enzymes are also present in other organs, where they participate in regulation of cholesterol metabolism. Those enzymes are potential targets for new drugs against cholesterol metabolism disturbances. This article is a brief description of the bile acid biosynthesis pathway and participating enzymes.

  19. Biosynthesis of polyhydroxyalkanotes in wildtype yeasts | Desuoky ...

    African Journals Online (AJOL)

    Biosynthesis of the biodegradable polymers polyhydroxyalkanotes (PHAs) are studied extensively in wild type and genetically modified prokaryotic cells, however the content and structure of PHA in wild type yeasts are not well documented. The purpose of this study was to screen forty yeast isolates collected from different ...

  20. Unedoside derivatives in Nuxia and their biosynthesis

    DEFF Research Database (Denmark)

    Jensen, Søren Rosendal; Ravnkilde, Lene; Schripsema, Jan

    1998-01-01

    isolated, while from N. oppositifolia 2 "-acetyl-3 "-benzoyl-nuxioside was obtained. Both plants contained verbascoside. The biosynthesis of unedoside in N. floribunda was investigated and deoxyloganic acid was found to be a precursor, similar to wh;lt was found for the eight-carbon iridoids in Thunbergia...

  1. Biosynthesis of furanochromones in Pimpinella monoica

    Indian Academy of Sciences (India)

    polyketide origin of their aromatic and pyrone rings while the furan ring originates via an acetate-mevalonate pathway. The plant also utilises glycine and leucine as substrate via acetate. Biotransformation of 3-H-visnagin to (6) but not to (2) was also observed. Keywords. Biosynthesis; furochromones; polyketide origin; ...

  2. Biosynthesis of silver nanoparticles synthesized by Aspergillus ...

    Indian Academy of Sciences (India)

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour ...

  3. RUNTIME DICTIONARIES FOR ROOT

    CERN Document Server

    Wind, David Kofoed

    2013-01-01

    ROOT is the LHC physicists' common tool for data analysis; almost all data is stored using ROOT's I/O system. This system benefits from a custom description of types (a so-called dictionary) that is optimised for the I/O. Until now, the dictionary cannot be provided at run-time; it needs to be prepared in a separate prerequisite step. This project will move the generation of the dictionary to run-time, making use of ROOT 6's new just-in-time compiler. It allows a more dynamic and natural access to ROOT's I/O features especially for user code.

  4. Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants

    Science.gov (United States)

    Yu, Yan; Jin, Chongwei; Sun, Chengliang; Wang, Jinghong; Ye, Yiquan; Zhou, Weiwei; Lu, Lingli; Lin, Xianyong

    2016-01-01

    Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5. Aluminium caused more root inhibition in Yangmai-5 and increased ethylene production at the root apices compared to Xi Aimai-1, whereas the effects were significantly reversed by ethylene biosynthesis inhibitors. The simultaneous exposure of wheat seedlings to Al and ethylene donor, ethephon, or ethylene biosynthesis precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), increased ethylene production and aggravated root inhibition, which was more pronounced in Xi Aimai-1. In contrast, Put treatment decreased ethylene production and alleviated Al-induced root inhibition in both genotypes, and the effects were more conspicuous in Yangmai-5. Furthermore, our results indicated that Al-induced ethylene production was mediated by ACC synthase (ACS) and ACC oxidase, and that Put decreased ethylene production by inhibiting ACS. Altogether, these findings indicate that ethylene is involved in Al-induced root inhibition and this process could be alleviated by Put through inhibiting ACS activity. PMID:26744061

  5. Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants.

    Science.gov (United States)

    Yu, Yan; Jin, Chongwei; Sun, Chengliang; Wang, Jinghong; Ye, Yiquan; Zhou, Weiwei; Lu, Lingli; Lin, Xianyong

    2016-01-08

    Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5. Aluminium caused more root inhibition in Yangmai-5 and increased ethylene production at the root apices compared to Xi Aimai-1, whereas the effects were significantly reversed by ethylene biosynthesis inhibitors. The simultaneous exposure of wheat seedlings to Al and ethylene donor, ethephon, or ethylene biosynthesis precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), increased ethylene production and aggravated root inhibition, which was more pronounced in Xi Aimai-1. In contrast, Put treatment decreased ethylene production and alleviated Al-induced root inhibition in both genotypes, and the effects were more conspicuous in Yangmai-5. Furthermore, our results indicated that Al-induced ethylene production was mediated by ACC synthase (ACS) and ACC oxidase, and that Put decreased ethylene production by inhibiting ACS. Altogether, these findings indicate that ethylene is involved in Al-induced root inhibition and this process could be alleviated by Put through inhibiting ACS activity.

  6. Events Associated with Early Age-Related Decline in Adventitious Rooting Competence of Eucalyptus globulus Labill

    Directory of Open Access Journals (Sweden)

    Márcio L. Aumond

    2017-10-01

    Full Text Available The development of adventitious roots is affected by several factors, including the age of the cutting donor plant, which negatively affects rooting capacity. Eucalyptus globulus quickly loses rooting capacity of cuttings as the donor plant ages, although the molecular and biochemical mechanisms behind this process are still unclear. To better understand the bases of rooting competence loss in E. globulus, the time required for a significant decline in rhizogenic ability without exogenous auxin was determined in microcuttings derived from donor plants of different ages after sowing. Tip cuttings of donor plants were severed before and after loss of rooting competence of microcuttings to test the hypothesis that auxin and carbohydrate homeostasis regulate rooting competence decline. There were no significant changes in concentration of carbohydrates, flavonoids, or proteins before and after the loss of rooting capacity. Peroxidase (EC 1.11.1.7 total activity increased with loss of rooting competence. Auxin concentration showed the opposite pattern. In good agreement, TAA1, a key gene in auxin biosynthesis, had lower expression after loss of rooting capacity. The same applied to the auxin receptor gene TIR1, suggesting reduced auxin sensitivity. On the other hand, genes associated with auxin response repression (TPL, IAA12 or with the action of cytokinins, the rhizogenesis inhibitor-related ARR1, showed higher expression in plants with lower rooting competence. Taken together, data suggest that age negatively affects E. globulus rooting by a combination of factors. Decreased endogenous auxin concentration, possibly caused by less biosynthesis, lower auxin sensitivity, higher expression of genes inhibiting auxin action, as well as of genes related to the action of cytokinins, appear to play roles in this process.

  7. Events Associated with Early Age-Related Decline in Adventitious Rooting Competence of Eucalyptus globulus Labill

    Science.gov (United States)

    Aumond, Márcio L.; de Araujo, Artur T.; de Oliveira Junkes, Camila F.; de Almeida, Márcia R.; Matsuura, Hélio N.; de Costa, Fernanda; Fett-Neto, Arthur G.

    2017-01-01

    The development of adventitious roots is affected by several factors, including the age of the cutting donor plant, which negatively affects rooting capacity. Eucalyptus globulus quickly loses rooting capacity of cuttings as the donor plant ages, although the molecular and biochemical mechanisms behind this process are still unclear. To better understand the bases of rooting competence loss in E. globulus, the time required for a significant decline in rhizogenic ability without exogenous auxin was determined in microcuttings derived from donor plants of different ages after sowing. Tip cuttings of donor plants were severed before and after loss of rooting competence of microcuttings to test the hypothesis that auxin and carbohydrate homeostasis regulate rooting competence decline. There were no significant changes in concentration of carbohydrates, flavonoids, or proteins before and after the loss of rooting capacity. Peroxidase (EC 1.11.1.7) total activity increased with loss of rooting competence. Auxin concentration showed the opposite pattern. In good agreement, TAA1, a key gene in auxin biosynthesis, had lower expression after loss of rooting capacity. The same applied to the auxin receptor gene TIR1, suggesting reduced auxin sensitivity. On the other hand, genes associated with auxin response repression (TPL, IAA12) or with the action of cytokinins, the rhizogenesis inhibitor-related ARR1, showed higher expression in plants with lower rooting competence. Taken together, data suggest that age negatively affects E. globulus rooting by a combination of factors. Decreased endogenous auxin concentration, possibly caused by less biosynthesis, lower auxin sensitivity, higher expression of genes inhibiting auxin action, as well as of genes related to the action of cytokinins, appear to play roles in this process. PMID:29067033

  8. Wild tobacco genomes reveal the evolution of nicotine biosynthesis.

    Science.gov (United States)

    Xu, Shuqing; Brockmöller, Thomas; Navarro-Quezada, Aura; Kuhl, Heiner; Gase, Klaus; Ling, Zhihao; Zhou, Wenwu; Kreitzer, Christoph; Stanke, Mario; Tang, Haibao; Lyons, Eric; Pandey, Priyanka; Pandey, Shree P; Timmermann, Bernd; Gaquerel, Emmanuel; Baldwin, Ian T

    2017-06-06

    Nicotine, the signature alkaloid of Nicotiana species responsible for the addictive properties of human tobacco smoking, functions as a defensive neurotoxin against attacking herbivores. However, the evolution of the genetic features that contributed to the assembly of the nicotine biosynthetic pathway remains unknown. We sequenced and assembled genomes of two wild tobaccos, Nicotiana attenuata (2.5 Gb) and Nicotiana obtusifolia (1.5 Gb), two ecological models for investigating adaptive traits in nature. We show that after the Solanaceae whole-genome triplication event, a repertoire of rapidly expanding transposable elements (TEs) bloated these Nicotiana genomes, promoted expression divergences among duplicated genes, and contributed to the evolution of herbivory-induced signaling and defenses, including nicotine biosynthesis. The biosynthetic machinery that allows for nicotine synthesis in the roots evolved from the stepwise duplications of two ancient primary metabolic pathways: the polyamine and nicotinamide adenine dinucleotide (NAD) pathways. In contrast to the duplication of the polyamine pathway that is shared among several solanaceous genera producing polyamine-derived tropane alkaloids, we found that lineage-specific duplications within the NAD pathway and the evolution of root-specific expression of the duplicated Solanaceae-specific ethylene response factor that activates the expression of all nicotine biosynthetic genes resulted in the innovative and efficient production of nicotine in the genus Nicotiana Transcription factor binding motifs derived from TEs may have contributed to the coexpression of nicotine biosynthetic pathway genes and coordinated the metabolic flux. Together, these results provide evidence that TEs and gene duplications facilitated the emergence of a key metabolic innovation relevant to plant fitness.

  9. The roots of nodulins.

    NARCIS (Netherlands)

    Nap, J.P.H.; Bisseling, T.

    1990-01-01

    Nodulin gene expression is an integral and highly specific part of the formation of nitrogenfixing nodules on the roots of leguminous plants. Dependent on the time of expression during root nodule development, nodulin genes can be divided into early and late nodulin genes. A brief overview of the

  10. Irrational Square Roots

    Science.gov (United States)

    Misiurewicz, Michal

    2013-01-01

    If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?

  11. Local Transcriptional Control of YUCCA Regulates Auxin Promoted Root-Growth Inhibition in Response to Aluminium Stress in Arabidopsis.

    Science.gov (United States)

    Liu, Guangchao; Gao, Shan; Tian, Huiyu; Wu, Wenwen; Robert, Hélène S; Ding, Zhaojun

    2016-10-01

    Auxin is necessary for the inhibition of root growth induced by aluminium (Al) stress, however the molecular mechanism controlling this is largely unknown. Here, we report that YUCCA (YUC), which encodes flavin monooxygenase-like proteins, regulates local auxin biosynthesis in the root apex transition zone (TZ) in response to Al stress. Al stress up-regulates YUC3/5/7/8/9 in the root-apex TZ, which we show results in the accumulation of auxin in the root-apex TZ and root-growth inhibition during the Al stress response. These Al-dependent changes in the regulation of YUCs in the root-apex TZ and YUC-regulated root growth inhibition are dependent on ethylene signalling. Increasing or disruption of ethylene signalling caused either enhanced or reduced up-regulation, respectively, of YUCs in root-apex TZ in response to Al stress. In addition, ethylene enhanced root growth inhibition under Al stress was strongly alleviated in yuc mutants or by co-treatment with yucasin, an inhibitor of YUC activity, suggesting a downstream role of YUCs in this process. Moreover, ethylene-insensitive 3 (EIN3) is involved into the direct regulation of YUC9 transcription in this process. Furthermore, we demonstrated that PHYTOCHROME INTERACTING FACTOR4 (PIF4) functions as a transcriptional activator for YUC5/8/9. PIF4 promotes Al-inhibited primary root growth by regulating the local expression of YUCs and auxin signal in the root-apex TZ. The Al-induced expression of PIF4 in root TZ acts downstream of ethylene signalling. Taken together, our results highlight a regulatory cascade for YUCs-regulated local auxin biosynthesis in the root-apex TZ mediating root growth inhibition in response to Al stress.

  12. Local Transcriptional Control of YUCCA Regulates Auxin Promoted Root-Growth Inhibition in Response to Aluminium Stress in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Guangchao Liu

    2016-10-01

    Full Text Available Auxin is necessary for the inhibition of root growth induced by aluminium (Al stress, however the molecular mechanism controlling this is largely unknown. Here, we report that YUCCA (YUC, which encodes flavin monooxygenase-like proteins, regulates local auxin biosynthesis in the root apex transition zone (TZ in response to Al stress. Al stress up-regulates YUC3/5/7/8/9 in the root-apex TZ, which we show results in the accumulation of auxin in the root-apex TZ and root-growth inhibition during the Al stress response. These Al-dependent changes in the regulation of YUCs in the root-apex TZ and YUC-regulated root growth inhibition are dependent on ethylene signalling. Increasing or disruption of ethylene signalling caused either enhanced or reduced up-regulation, respectively, of YUCs in root-apex TZ in response to Al stress. In addition, ethylene enhanced root growth inhibition under Al stress was strongly alleviated in yuc mutants or by co-treatment with yucasin, an inhibitor of YUC activity, suggesting a downstream role of YUCs in this process. Moreover, ethylene-insensitive 3 (EIN3 is involved into the direct regulation of YUC9 transcription in this process. Furthermore, we demonstrated that PHYTOCHROME INTERACTING FACTOR4 (PIF4 functions as a transcriptional activator for YUC5/8/9. PIF4 promotes Al-inhibited primary root growth by regulating the local expression of YUCs and auxin signal in the root-apex TZ. The Al-induced expression of PIF4 in root TZ acts downstream of ethylene signalling. Taken together, our results highlight a regulatory cascade for YUCs-regulated local auxin biosynthesis in the root-apex TZ mediating root growth inhibition in response to Al stress.

  13. Phosphate starvation of maize inhibits lateral root formation and alters gene expression in the lateral root primordium zone

    Directory of Open Access Journals (Sweden)

    Li Zhaoxia

    2012-06-01

    Full Text Available Abstract Background Phosphorus (P is an essential macronutrient for all living organisms. Maize (Zea mays is an important human food, animal feed and energy crop throughout the world, and enormous quantities of phosphate fertilizer are required for maize cultivation. Thus, it is important to improve the efficiency of the use of phosphate fertilizer for maize. Results In this study, we analyzed the maize root response to phosphate starvation and performed a transcriptomic analysis of the 1.0-1.5 cm lateral root primordium zone. In the growth of plants, the root-to-shoot ratio (R/L was reduced in both low-phosphate (LP and sufficient-phosphate (SP solutions, but the ratio (R/L exhibited by the plants in the LP solution was higher than that of the SP plants. The growth of primary roots was slightly promoted after 6 days of phosphate starvation, whereas the numbers of lateral roots and lateral root primordia were significantly reduced, and these differences were increased when associated with the stress caused by phosphate starvation. Among the results of a transcriptomic analysis of the maize lateral root primordium zone, there were two highlights: 1 auxin signaling participated in the response and the modification of root morphology under low-phosphate conditions, which may occur via local concentration changes due to the biosynthesis and transport of auxin, and LOB domain proteins may be an intermediary between auxin signaling and root morphology; and 2 the observed retardation of lateral root development was the result of co-regulation of DNA replication, transcription, protein synthesis and degradation and cell growth. Conclusions These results indicated that maize roots show a different growth pattern than Arabidopsis under low-phosphate conditions, as the latter species has been observed to halt primary root growth when the root tip comes into contact with low-phosphate media. Moreover, our findings enrich our understanding of plant

  14. Distinguishability of Biological Material Using Ultraviolet Multi-Spectral Fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P.C.; Heinen, R.J.; Rigdon, L.D.; Rosenthal, S.E.; Shokair, I.R.; Siragusa, G.R.; Tisone, G.C.; Wagner, J.S.

    1998-10-14

    Recent interest in the detection and analysis of biological samples by spectroscopic methods has led to questions concerning the degree of distinguishability and biological variability of the ultraviolet (W) fluorescent spectra from such complex samples. We show that the degree of distinguishability of such spectra is readily determined numerically.

  15. Distinguishing attack on five-round Feistel networks

    DEFF Research Database (Denmark)

    Knudsen, Lars Ramkilde; Raddum, H

    2003-01-01

    Recently it was shown (by J. Patarin) how to distinguish a general five-round Feistel network from a random permutation using O(2/sup 3n/2/) chosen plaintexts or O(2/sup 7n/4/) known plaintexts. The present authors report improvement of these results and a distinguisher is presented which uses ro...

  16. Charles L. Brewer Distinguished Teaching of Psychology Award.

    Science.gov (United States)

    2014-01-01

    The American Psychological Foundation (APF) Charles L. Brewer Award for Distinguished Teaching of Psychology recognizes an outstanding career contribution to the teaching of psychology. The 2014 recipient of the Charles L. Brewer Distinguished Teaching of Psychology Award is Mary E. Kite. 2014 APA, all rights reserved

  17. Identical Distinguishable Gas Particles in the Real World

    Indian Academy of Sciences (India)

    IAS Admin

    indistinguishable particles or of nonidentical distinguishable particles, it requires more care to identify a gas of identical distinguishable particles. In undergraduate physics courses treating either quantum me- chanics or classical statistical mechanics, students are introduced to the concept of a gas of particles which may be ...

  18. Analysis of Arabidopsis mutants deficient in flavonoid biosynthesis

    International Nuclear Information System (INIS)

    Shirley, B.W.; Kubasek, W.L.; Storz, G.; Bruggemann, E.; Koornneef, M.; Ausubel, F.M.; Goodman, H.M.

    1995-01-01

    Eleven loci that play a role in the synthesis of flavonoids in Arabidopsis are described. Mutations at these loci, collectively named transparent testa (tt), disrupt the synthesis of brown pigments in the seed coat (testa). Several of these loci (tt3, tt4, tt5 and ttg) are also required for the accumulation of purple anthocyanins in leaves and stems and one locus (ttg) plays additional roles in trichome and root hair development. Specific functions were previously assigned to tt1-7 and ttg. Here, the results of additional genetic, biochemical and molecular analyses of these mutants are described. Genetic map positions were determined for tt8, tt9 and tt10. Thin-layer chromatography identified tissue- and locus-specific differences in the flavonols and anthocyanidins synthesized by mutant and wild-type plants. It was found that UV light reveals distinct differences in the floral tissues of tt3, tt4, tt5, tt6 and ttg, even though these tissues are indistinguishable under visible light. Evidence was also uncovered that tt8 and ttg specifically affect dihydroflavonol reductase gene expression. A summary of these and previously published results are incorporated into an overview of the genetics of flavonoid biosynthesis in Arabidopsis

  19. Proteolytic Pathways Induced by Herbicides That Inhibit Amino Acid Biosynthesis

    Science.gov (United States)

    Zulet, Amaia; Gil-Monreal, Miriam; Villamor, Joji Grace; Zabalza, Ana; van der Hoorn, Renier A. L.; Royuela, Mercedes

    2013-01-01

    Background The herbicides glyphosate (Gly) and imazamox (Imx) inhibit the biosynthesis of aromatic and branched-chain amino acids, respectively. Although these herbicides inhibit different pathways, they have been reported to show several common physiological effects in their modes of action, such as increasing free amino acid contents and decreasing soluble protein contents. To investigate proteolytic activities upon treatment with Gly and Imx, pea plants grown in hydroponic culture were treated with Imx or Gly, and the proteolytic profile of the roots was evaluated through fluorogenic kinetic assays and activity-based protein profiling. Results Several common changes in proteolytic activity were detected following Gly and Imx treatment. Both herbicides induced the ubiquitin-26 S proteasome system and papain-like cysteine proteases. In contrast, the activities of vacuolar processing enzymes, cysteine proteases and metacaspase 9 were reduced following treatment with both herbicides. Moreover, the activities of several putative serine protease were similarly increased or decreased following treatment with both herbicides. In contrast, an increase in YVADase activity was observed under Imx treatment versus a decrease under Gly treatment. Conclusion These results suggest that several proteolytic pathways are responsible for protein degradation upon herbicide treatment, although the specific role of each proteolytic activity remains to be determined. PMID:24040092

  20. ADP1 Affects Plant Architecture by Regulating Local Auxin Biosynthesis

    Science.gov (United States)

    Li, Shibai; Qin, Genji; Novák, Ondřej; Pěnčík, Aleš; Ljung, Karin; Aoyama, Takashi; Liu, Jingjing; Murphy, Angus; Gu, Hongya; Tsuge, Tomohiko; Qu, Li-Jia

    2014-01-01

    Plant architecture is one of the key factors that affect plant survival and productivity. Plant body structure is established through the iterative initiation and outgrowth of lateral organs, which are derived from the shoot apical meristem and root apical meristem, after embryogenesis. Here we report that ADP1, a putative MATE (multidrug and toxic compound extrusion) transporter, plays an essential role in regulating lateral organ outgrowth, and thus in maintaining normal architecture of Arabidopsis. Elevated expression levels of ADP1 resulted in accelerated plant growth rate, and increased the numbers of axillary branches and flowers. Our molecular and genetic evidence demonstrated that the phenotypes of plants over-expressing ADP1 were caused by reduction of local auxin levels in the meristematic regions. We further discovered that this reduction was probably due to decreased levels of auxin biosynthesis in the local meristematic regions based on the measured reduction in IAA levels and the gene expression data. Simultaneous inactivation of ADP1 and its three closest homologs led to growth retardation, relative reduction of lateral organ number and slightly elevated auxin level. Our results indicated that ADP1-mediated regulation of the local auxin level in meristematic regions is an essential determinant for plant architecture maintenance by restraining the outgrowth of lateral organs. PMID:24391508

  1. Identification of anthocyanin biosynthesis related microRNAs in a distinctive Chinese radish (Raphanus sativus L.) by high-throughput sequencing.

    Science.gov (United States)

    Sun, Yuyan; Qiu, Yang; Duan, Mengmeng; Wang, Jinglei; Zhang, Xiaohui; Wang, Haiping; Song, Jiangping; Li, Xixiang

    2017-02-01

    Anthocyanins are widely distributed water-soluble phytochemical pigments belonging to the flavonoid group. To date, limited knowledge is available about the regulatory roles of miRNAs in anthocyanin biosynthesis in plants. To identify the miRNAs associated with anthocyanin biosynthesis in radish, five small RNA (sRNA) libraries constructed from 'Xinlimei' radish roots at 11, 21, 44, 56 and 73 days (d) were examined using high-throughput sequencing technology. A total of 102.02 million (M) clean reads were generated, from which 483 known and 1415 novel miRNAs were identified. Combined with target prediction and annotation, 72 differentially expressed miRNAs (52 known and 20 novel miRNAs) were more likely to participate in anthocyanin biosynthesis. Several target genes for these miRNAs encode a few transcription factors, including Myb domain (MYB), basic helix-loop-helix (bHLH), WD40 repeat, squamosa promoter binding protein like (SPL), auxin response factor (ARF), ethylene insensitive 3 (EIN3), WRKY and MADS-box proteins. Furthermore, the expression patterns of some anthocyanin biosynthesis related miRNAs and their corresponding targets were validated by RT-qPCR. Based on the characterization of anthocyanin biosynthesis related miRNAs and their target genes, a putative miRNA-target module regulating anthocyanin biosynthesis was proposed. This study represents the first genome-wide identification of miRNAs associated with anthocyanin biosynthesis in radish, and provides insights into the molecular mechanisms underlying regulation of anthocyanin biosynthesis in radish and other crops.

  2. Enhancement of Thiamine Biosynthesis in Oil Palm Seedlings by Colonization of Endophytic Fungus Hendersonia toruloidea.

    Science.gov (United States)

    Kamarudin, Amirah N; Lai, Kok S; Lamasudin, Dhilia U; Idris, Abu S; Balia Yusof, Zetty N

    2017-01-01

    Thiamine, or vitamin B1 plays an indispensable role as a cofactor in crucial metabolic reactions including glycolysis, pentose phosphate pathway and the tricarboxylic acid cycle in all living organisms. Thiamine has been shown to play a role in plant adaptation toward biotic and abiotic stresses. The modulation of thiamine biosynthetic genes in oil palm seedlings was evaluated in response to root colonization by endophytic Hendersonia toruloidea . Seven-month-old oil palm seedlings were inoculated with H. toruloidea and microscopic analyses were performed to visualize the localization of endophytic H. toruloidea in oil palm roots. Transmission electron microscopy confirmed that H. toruloidea colonized cortical cells. The expression of thiamine biosynthetic genes and accumulation of total thiamine in oil palm seedlings were also evaluated. Quantitative real-time PCR was performed to measure transcript abundances of four key thiamine biosynthesis genes ( THI4 , THIC , TH1 , and TPK ) on days 1, 7, 15, and 30 in response to H. toruloidea colonization. The results showed an increase of up to 12-fold in the expression of all gene transcripts on day 1 post-inoculation. On days 7, 15, and 30 post-inoculation, the relative expression levels of these genes were shown to be downregulated. Thiamine accumulation was observed on day 7 post-colonization and subsequently decreased until day 30. This work provides the first evidence for the enhancement of thiamine biosynthesis by endophytic colonization in oil palm seedlings.

  3. Combinatorial biosynthesis of polyketides--a perspective.

    Science.gov (United States)

    Wong, Fong T; Khosla, Chaitan

    2012-04-01

    Since their discovery, polyketide synthases have been attractive targets of biosynthetic engineering to make 'unnatural' natural products. Although combinatorial biosynthesis has made encouraging advances over the past two decades, the field remains in its infancy. In this enzyme-centric perspective, we discuss the scientific and technological challenges that could accelerate the adoption of combinatorial biosynthesis as a method of choice for the preparation of encoded libraries of bioactive small molecules. Borrowing a page from the protein structure prediction community, we propose a periodic challenge program to vet the most promising methods in the field, and to foster the collective development of useful tools and algorithms. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Structural basis for phosphatidylinositol-phosphate biosynthesis

    Science.gov (United States)

    Clarke, Oliver B.; Tomasek, David; Jorge, Carla D.; Dufrisne, Meagan Belcher; Kim, Minah; Banerjee, Surajit; Rajashankar, Kanagalaghatta R.; Shapiro, Lawrence; Hendrickson, Wayne A.; Santos, Helena; Mancia, Filippo

    2015-10-01

    Phosphatidylinositol is critical for intracellular signalling and anchoring of carbohydrates and proteins to outer cellular membranes. The defining step in phosphatidylinositol biosynthesis is catalysed by CDP-alcohol phosphotransferases, transmembrane enzymes that use CDP-diacylglycerol as donor substrate for this reaction, and either inositol in eukaryotes or inositol phosphate in prokaryotes as the acceptor alcohol. Here we report the structures of a related enzyme, the phosphatidylinositol-phosphate synthase from Renibacterium salmoninarum, with and without bound CDP-diacylglycerol to 3.6 and 2.5 Å resolution, respectively. These structures reveal the location of the acceptor site, and the molecular determinants of substrate specificity and catalysis. Functional characterization of the 40%-identical ortholog from Mycobacterium tuberculosis, a potential target for the development of novel anti-tuberculosis drugs, supports the proposed mechanism of substrate binding and catalysis. This work therefore provides a structural and functional framework to understand the mechanism of phosphatidylinositol-phosphate biosynthesis.

  5. Occurrence and biosynthesis of carotenoids in phytoplankton.

    Science.gov (United States)

    Huang, Jim Junhui; Lin, Shaoling; Xu, Wenwen; Cheung, Peter Chi Keung

    2017-09-01

    Naturally occurring carotenoids are important sources of antioxidants, anti-cancer compounds and anti-inflammatory agents and there is thus considerable market demand for their pharmaceutical applications. Carotenoids are widely distributed in marine and freshwater organisms including microalgae, phytoplankton, crustaceans and fish, as well as in terrestrial plants and birds. Recently, phytoplankton-derived carotenoids have received much attention due to their abundance, rapid rate of biosynthesis and unique composition. The carotenoids that accumulate in particular phytoplankton phyla are synthesized by specific enzymes and play unique physiological roles. This review focuses on studies related to the occurrence of carotenoids in different phytoplankton phyla and the molecular aspects of their biosynthesis. Recent biotechnological advances in the isolation and characterization of some representative carotenoid synthases in phytoplankton are also discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Chemical genetics to examine cellulose biosynthesis

    Directory of Open Access Journals (Sweden)

    Seth eDebolt

    2013-01-01

    Full Text Available Long-term efforts to decode plant cellulose biosynthesis via molecular genetics and biochemical strategies are being enhanced by the ever-expanding scale of omics technologies. An alternative approach to consider are the prospects for inducing change in plant metabolism using exogenously supplied chemical ligands. Cellulose biosynthesis inhibitors (CBI have been identified among known herbicides, during diverse combinatorial chemical libraries screens, and natural chemical screens from microbial agents. In this review, we summarize the current knowledge of the inhibitory effects of CBIs and further group them by how they influence fluorescently tagged cellulose synthase A (CESA proteins. Additional attention is paid to the continuing development of the CBI toolbox to explore the cell biology and genetic mechanisms underpinning effector molecule activity.

  7. A Radish Basic Helix-Loop-Helix Transcription Factor, RsTT8 Acts a Positive Regulator for Anthocyanin Biosynthesis

    Directory of Open Access Journals (Sweden)

    Sun-Hyung Lim

    2017-11-01

    Full Text Available The MYB-bHLH-WDR (MBW complex activates anthocyanin biosynthesis through the transcriptional regulation. RsMYB1 has been identified as a key player in anthocyanin biosynthesis in red radish (Raphanus sativus L., but its partner bHLH transcription factor (TF remains to be determined. In this study, we isolated a bHLH TF gene from red radish. Phylogenetic analysis indicated that this gene belongs to the TT8 clade of the IIIF subgroup of bHLH TFs, and we thus designated this gene RsTT8. Subcellular localization analysis showed that RsTT8-sGFP was localized to the nuclei of Arabidopsis thaliana protoplasts harboring the RsTT8-sGFP construct. We evaluated anthocyanin biosynthesis and RsTT8 expression levels in three radish varieties (N, C, and D that display different red phenotypes in the leaves, root flesh, and root skins. The root flesh of the C variety and the leaves and skins of the D variety exhibit intense red pigmentation; in these tissues, RsTT8 expression showed totally positive association with the expression of RsMYB1 TF and of five of eight tested anthocyanin biosynthesis genes (i.e., RsCHS, RsCHI, RsF3H, RsDFR, and RsANS. Heterologous co-expression of both RsTT8 and RsMYB1 in tobacco leaves dramatically increased the expression of endogenous anthocyanin biosynthesis genes and anthocyanin accumulation. Furthermore, a yeast two-hybrid assay showed that RsTT8 interacts with RsMYB1 at the MYB-interacting region (MIR, and a transient transactivation assay indicated that RsTT8 activates the RsCHS and RsDFR promoters when co-expressed with RsMYB1. Complementation of the Arabidopsis tt8-1 mutant, which lacks red pigmentation in the leaves and seeds, with RsTT8 restored red pigmentation, and resulted in high anthocyanin and proanthocyanidin contents in the leaves and seeds, respectively. Together, these results show that RsTT8 functions as a regulatory partner with RsMYB1 during anthocyanin biosynthesis.

  8. Discovery, Biosynthesis and Stress-Related Accumulation of Dolabradiene-Derived Defenses in Maize.

    Science.gov (United States)

    Mafu, Sibongile; Ding, Yezhang; Murphy, Katherine M; Yaacoobi, Omar; Addison, J Bennett; Wang, Qiang; Shen, Zhouxin; Briggs, Steven P; Bohlmann, Jörg; Castro-Falcon, Gabriel; Hughes, Chambers C; Betsiashvili, Mariam; Huffaker, Alisa; Schmelz, Eric A; Zerbe, Philipp

    2018-04-01

    Terpenoids are a major component of maize ( Zea mays ) chemical defenses that mediate responses to herbivores, pathogens, and other environmental challenges. Here, we describe the biosynthesis and elicited production of a class of maize diterpenoids, named dolabralexins. Dolabralexin biosynthesis involves the sequential activity of two diterpene synthases, ENT -COPALYL DIPHOSPHATE SYNTHASE (ZmAN2) and KAURENE SYNTHASE-LIKE4 (ZmKSL4). Together, ZmAN2 and ZmKSL4 form the diterpene hydrocarbon dolabradiene. In addition, we biochemically characterized a cytochrome P450 monooxygenase, ZmCYP71Z16, which catalyzes the oxygenation of dolabradiene to yield the epoxides 15,16-epoxydolabrene (epoxydolabrene) and 3β-hydroxy-15,16-epoxydolabrene (epoxydolabranol). The absence of dolabradiene and epoxydolabranol in Zman2 mutants under elicited conditions confirmed the in vivo biosynthetic requirement of ZmAN2. Combined mass spectrometry and NMR experiments demonstrated that much of the epoxydolabranol is further converted into 3β,15,16-trihydroxydolabrene (trihydroxydolabrene). Metabolite profiling of field-grown maize root tissues indicated that dolabralexin biosynthesis is widespread across common maize cultivars, with trihydroxydolabrene as the predominant diterpenoid. Oxidative stress induced dolabralexin accumulation and transcript expression of ZmAN2 and ZmKSL4 in root tissues, and metabolite and transcript accumulation were up-regulated in response to elicitation with the fungal pathogens Fusarium verticillioides and Fusarium graminearum Consistently, epoxydolabranol significantly inhibited the growth of both pathogens in vitro at 10 µg mL -1 , while trihydroxydolabrene-mediated inhibition was specific to F verticillioides These findings suggest that dolabralexins have defense-related roles in maize stress interactions and expand the known chemical space of diterpenoid defenses as genetic targets for understanding and ultimately improving maize resilience. © 2018

  9. Microbial biosynthesis of nontoxic gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Swarup, E-mail: swaruproy@klyuniv.ac.in [Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal (India); Das, Tapan Kumar [Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, West Bengal (India); Maiti, Guru Prasad [Department of Molecular Biology and Biotechnology, University of Kalyani, Kalyani 741235, West Bengal (India); Department of Anesthesiology, Texas Tech University Health science Center, 3601 4th Street, Lubbock, TX 79430 (United States); Basu, Utpal [Department of Molecular Biology and Biotechnology, University of Kalyani, Kalyani 741235, West Bengal (India)

    2016-01-15

    Graphical abstract: The manuscript deals with the fungus mediated optimized biologically synthesized GNPs using Aspergillus foetidus and characterization of biosynthesized GNPs using various physico-chemical methods. The fairly stable synthesized nanoparticles have size in the range of 10–40 nm. Cytotoxicity study of biosynthesized GNPs on Human lung cancer cell line A549 showed no significant toxicity of GNPs. - Highlights: • A novel biosynthesis process of GNPs using Aspergillus foetidus. • Biosynthesized GNPs are in the range of 10–40 nm as observed from TEM. • This process of synthesis is an optimized biosynthesis process of GNPs. • Biosynthesized GNPs are noncytotoxic against A549 cell line. - Abstract: We study the extracellular biosynthesis of gold nanoparticles (GNPs) using the fungal species Aspergillus foetidus. The formation of GNPs were initially monitored by visual observation and then characterized with the help of various characterization techniques. X-ray diffraction (XRD) results revealed distinctive formation of face centered cubic crystalline GNPs. From field emission scanning electron microscopy (FESEM) the morphology of the nanoparticles were found to be roughly spherical and within the size range of 30–50 nm. The spherical and polydispersed GNPs in the range of 10–40 nm were observed by transmission electron microscopy (TEM) analysis. It was established that alkaline pH, 1 mM gold salt concentration and 75 °C temperature were the respective optimum parameter for biosynthesis of GNPs. Cell cytotoxicity of GNP was compared with that of normal gold salt solution on A549 cell. The A549 cell growth in presence of GNPs was found to be comparatively less toxic than the gold ion.

  10. Microbial biosynthesis of nontoxic gold nanoparticles

    International Nuclear Information System (INIS)

    Roy, Swarup; Das, Tapan Kumar; Maiti, Guru Prasad; Basu, Utpal

    2016-01-01

    Graphical abstract: The manuscript deals with the fungus mediated optimized biologically synthesized GNPs using Aspergillus foetidus and characterization of biosynthesized GNPs using various physico-chemical methods. The fairly stable synthesized nanoparticles have size in the range of 10–40 nm. Cytotoxicity study of biosynthesized GNPs on Human lung cancer cell line A549 showed no significant toxicity of GNPs. - Highlights: • A novel biosynthesis process of GNPs using Aspergillus foetidus. • Biosynthesized GNPs are in the range of 10–40 nm as observed from TEM. • This process of synthesis is an optimized biosynthesis process of GNPs. • Biosynthesized GNPs are noncytotoxic against A549 cell line. - Abstract: We study the extracellular biosynthesis of gold nanoparticles (GNPs) using the fungal species Aspergillus foetidus. The formation of GNPs were initially monitored by visual observation and then characterized with the help of various characterization techniques. X-ray diffraction (XRD) results revealed distinctive formation of face centered cubic crystalline GNPs. From field emission scanning electron microscopy (FESEM) the morphology of the nanoparticles were found to be roughly spherical and within the size range of 30–50 nm. The spherical and polydispersed GNPs in the range of 10–40 nm were observed by transmission electron microscopy (TEM) analysis. It was established that alkaline pH, 1 mM gold salt concentration and 75 °C temperature were the respective optimum parameter for biosynthesis of GNPs. Cell cytotoxicity of GNP was compared with that of normal gold salt solution on A549 cell. The A549 cell growth in presence of GNPs was found to be comparatively less toxic than the gold ion.

  11. Tetrahydrobiopterin biosynthesis, utilization and pharmacological effects.

    Science.gov (United States)

    Werner-Felmayer, G; Golderer, G; Werner, E R

    2002-04-01

    Tetrahydrobiopterin (H4-biopterin) is an essential cofactor of a set of enzymes that are of central metabolic importance, i.e. the hydroxylases of the three aromatic amino acids phenylalanine, tyrosine, and tryptophan, of ether lipid oxidase, and of the three nitric oxide synthase (NOS) isoenzymes. As a consequence, H4-biopterin plays a key role in a vast number of biological processes and pathological states associated with neurotransmitter formation, vasorelaxation, and immune response. In mammals, its biosynthesis is controlled by hormones, cytokines and certain immune stimuli. This review aims to summarize recent developments concerning regulation of H4-biopterin biosynthetic and regulatory enzymes and pharmacological effects of H4-biopterin in various conditions, e.g. endothelial dysfunction or apoptosis of neuronal cells. Also, approaches towards gene therapy of diseases like the different forms of phenylketonuria or of Parkinson's disease are reviewed. Additional emphasis is given to H4-biopterin biosynthesis and function in non-mammalian species such as fruit fly, zebra fish, fungi, slime molds, the bacterium Nocardia as well as to the parasitic protozoan genus of Leishmania that is not capable of pteridine biosynthesis but has evolved a sophisticated salvage network for scavenging various pteridine compounds, notably folate and biopterin.

  12. Exopolysaccharide biosynthesis by Lactobacillus helveticus ATCC 15807.

    Science.gov (United States)

    Torino, M I; Mozzi, F; Font de Valdez, G

    2005-08-01

    Exopolysaccharide (EPS) production and the activities of the enzymes involved in sugar nucleotide biosynthesis in Lactobacillus helveticus ATCC 15807 under controlled pH conditions were investigated. Batch fermentations using lactose as energy source showed higher EPS synthesis by L. helveticus ATCC 15807 at pH 4.5 with respect to pH 6.2, the enzyme alpha-phosphoglucomutase (alpha-PGM) being correlated with both total and specific EPS production. When glucose was used as carbon source instead of lactose, the lower EPS synthesis obtained was linked to a decrease in alpha-PGM and galactose 1-phosphate-uridyltransferase (GalT) activities, the reduction of the latter being more pronounced. Higher EPS production by L. helveticus ATCC 15807 at the acidic constant pH of 4.5 requires that both alpha-PGM and GalT activities are high. These enzymes are needed to synthesize UDP-glucose and UDP-galactose for supplying the corresponding monomers for EPS biosynthesis. Although differences are observed in EPS production by this strain regarding the energy source (lactose or glucose), the monomeric composition of the polymers produced is independent of the carbohydrate used. The obtained results contribute to a better understanding of the physiological factors that affect EPS biosynthesis by lactobacilli, which could help in the correct handling of the fermentation parameters within the fermented dairy industry.

  13. Lipopolysaccharide Structure and Biosynthesis in Helicobacter pylori.

    Science.gov (United States)

    Li, Hong; Liao, Tingting; Debowski, Aleksandra W; Tang, Hong; Nilsson, Hans-Olof; Stubbs, Keith A; Marshall, Barry J; Benghezal, Mohammed

    2016-12-01

    This review covers the current knowledge and gaps in Helicobacter pylori lipopolysaccharide (LPS) structure and biosynthesis. H. pylori is a Gram-negative bacterium which colonizes the luminal surface of the human gastric epithelium. Both a constitutive alteration of the lipid A preventing TLR4 elicitation and host mimicry of the Lewis antigen decorated O-antigen of H. pylori LPS promote immune escape and chronic infection. To date, the complete structure of H. pylori LPS is not available, and the proposed model is a linear arrangement composed of the inner core defined as the hexa-saccharide (Kdo-LD-Hep-LD-Hep-DD-Hep-Gal-Glc), the outer core composed of a conserved trisaccharide (-GlcNAc-Fuc-DD-Hep-) linked to the third heptose of the inner core, the glucan, the heptan and a variable O-antigen, generally consisting of a poly-LacNAc decorated with Lewis antigens. Although the glycosyltransferases (GTs) responsible for the biosynthesis of the H. pylori O-antigen chains have been identified and characterized, there are many gaps in regard to the biosynthesis of the core LPS. These limitations warrant additional mutagenesis and structural studies to obtain the complete LPS structure and corresponding biosynthetic pathway of this important gastric bacterium. © 2016 John Wiley & Sons Ltd.

  14. Distinguishability of countable quantum states and von Neumann lattice

    International Nuclear Information System (INIS)

    Kawakubo, Ryûitirô; Koike, Tatsuhiko

    2016-01-01

    The condition for distinguishability of a countably infinite number of pure states by a single measurement is given. Distinguishability is to be understood as the possibility of an unambiguous measurement. For a finite number of states, it is known that the necessary and sufficient condition of distinguishability is that the states are linearly independent. For an infinite number of states, several natural classes of distinguishability can be defined. We give a necessary and sufficient condition for a system of pure states to be distinguishable. It turns out that each level of distinguishability naturally corresponds to one of the generalizations of linear independence to families of infinite vectors. As an important example, we apply the general theory to von Neumann’s lattice, a subsystem of coherent states which corresponds to a lattice in the classical phase space. We prove that the condition for distinguishability is that the area of the fundamental region of the lattice is greater than the Planck constant, and also find subtle behavior on the threshold. These facts reveal the measurement theoretical meaning of the Planck constant and give a justification for the interpretation that it is the smallest unit of area in the phase space. The cases of uncountably many states and of mixed states are also discussed. (paper)

  15. Identification and characterization of ANAC042, a transcription factor family gene involved in the regulation of camalexin biosynthesis in Arabidopsis.

    Science.gov (United States)

    Saga, Hirohisa; Ogawa, Takumi; Kai, Kosuke; Suzuki, Hideyuki; Ogata, Yoshiyuki; Sakurai, Nozomu; Shibata, Daisuke; Ohta, Daisaku

    2012-05-01

    Camalexin is the major phytoalexin in Arabidopsis. An almost complete set of camalexin biosynthetic enzymes have been elucidated but only limited information is available regarding molecular mechanisms regulating camalexin biosynthesis. Here, we demonstrate that ANAC042, a member of the NAM, ATAF1/2, and CUC2 (NAC) transcription factor family genes, is involved in camalexin biosynthesis induction. T-DNA insertion mutants of ANAC042 failed to accumulate camalexin at the levels achieved in the wild type, and were highly susceptible to Alternaria brassicicola infection. The camalexin biosynthetic genes CYP71A12, CYP71A13, and CYP71B15/PAD3 were not fully induced in the mutants, indicating that the camalexin defects were at least partly a result of reduced expression levels of these P450 genes. β-Glucuronidase (GUS)-reporter assays demonstrated tissue-specific induction of ANAC042 in response to differential pathogen infections. Bacterial flagellin (Flg22) induced ANAC042 expression in the root-elongation zone, the camalexin biosynthetic site, and the induction was abolished in the presence of either a general kinase inhibitor (K252a), a Ca(2+)-chelator (BAPTA), or methyl jasmonate. The GUS-reporter assay revealed repression of the Flg22-dependent ANAC042 expression in the ethylene-insensitive ein2-1 background but not in sid2-2 plants defective for salicylic acid biosynthesis. We discuss ANAC042 as a key transcription factor involved in previously unknown regulatory mechanisms to induce phytoalexin biosynthesis in Arabidopsis.

  16. 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.

  17. Identification of a Second Site of Pyrrolizidine Alkaloid Biosynthesis in Comfrey to Boost Plant Defense in Floral Stage.

    Science.gov (United States)

    Kruse, Lars H; Stegemann, Thomas; Sievert, Christian; Ober, Dietrich

    2017-05-01

    Pyrrolizidine alkaloids (PAs) are toxic secondary metabolites that are found in several distantly related families of the angiosperms. The first specific step in PA biosynthesis is catalyzed by homospermidine synthase (HSS), which has been recruited several times independently by duplication of the gene encoding deoxyhypusine synthase, an enzyme involved in the posttranslational activation of the eukaryotic initiation factor 5A. HSS shows highly diverse spatiotemporal gene expression in various PA-producing species. In comfrey ( Symphytum officinale ; Boraginaceae), PAs are reported to be synthesized in the roots, with HSS being localized in cells of the root endodermis. Here, we show that comfrey plants activate a second site of HSS expression when inflorescences start to develop. HSS has been localized in the bundle sheath cells of specific leaves. Tracer feeding experiments have confirmed that these young leaves express not only HSS but the whole PA biosynthetic route. This second site of PA biosynthesis results in drastically increased PA levels within the inflorescences. The boost of PA biosynthesis is proposed to guarantee optimal protection especially of the reproductive structures. © 2017 American Society of Plant Biologists. All Rights Reserved.

  18. The relationship between thiamine and two symbioses: Root nodule symbiosis and arbuscular mycorrhiza.

    Science.gov (United States)

    Nagae, Miwa; Parniske, Martin; Kawaguchi, Masayoshi; Takeda, Naoya

    2016-12-01

    Lotus japonicus THIC is expressed in all organs, and the encoded protein catalyzes thiamine biosynthesis. Loss of function produces chlorosis, a typical thiamine-deficiency phenotype, and mortality. To investigate thiamine's role in symbiosis, we focused on THI1, a thiamine-biosynthesis gene expressed in roots, nodules, and seeds. The thi1 mutant had green leaves, but formed small nodules and immature seeds. These phenotypes were rescued by THI1 complementation and by exogenous thiamine. Thus, THI1 is required for nodule enlargement and seed maturation. On the other hand, colonization by arbuscular mycorrhiza (AM) fungus Rhizophagus irregularis was not affected in the thi1 mutant or by exogenous thiamine. However, spores of R. irregularis stored more thiamine than the source (host plants), despite lacking thiamine biosynthesis genes. Therefore, disturbance of the thiamine supply would affect progeny phenotypes such as spore formation and hyphal growth. Further investigation will be required to elucidate thiamine's effect on AM.

  19. Biosynthesis and biotransformation of bile acids

    Directory of Open Access Journals (Sweden)

    Šarenac Tanja M.

    2017-01-01

    Full Text Available Bile acids are steroidal compounds, which contain 24 carbon atoms. They can be classified into two major groups: primary and secondary. The most abundant bile acids: The primary bile acids include cholic acid and chenodeoxycholic acid, while the major secondary bile acids are deoxycholic acid and litocholic acid. Bile acids are important physiological agents for intestinal absorption of nutrients and are used for biliary lipid secretion, toxic metabolites and xenobiotics. The aim of this paper is to analyze biosynthesis and biotransformation of bile acids, as preparation for practical usage in laboratory and clinical conditions. Topic: Biosynthesis and biotransformation of bile acids: The biosynthesis of bile acids is the dominant metabolic pathway for catabolism of cholesterol in humans. The classical route of biosynthesis of bile acids is embarking on the conversion of cholesterol into 7α-hydroxycholesterol using enzyme 7α-cholesterol hydroxylase (CYP7A1. This enzyme is one of the microsomal cytochrome P450 enzyme is localized exclusively in the liver. Classical road is the main road in the biosynthesis of bile acids, and its total contribution amounts to 90% for people, and 75% in mice. CYP 7A1 enzyme is considered to be sensitive to the inhibition of carbon monoxide, and the condition for the effect of NADPH, the oxygen, lecithin, and the NADPH-cytochrome P450 reductase. Bile acids are important signaling molecules and metabolic controls which activate the nuclear receptor and the G protein-coupled receptors (GPCR, a signaling lipid regulation of the liver, glucose and energy homeostasis. Also, bile acids maintain metabolic homeostasis. Biotransformation of bile acids: The conversion of cholesterol into bile acids just important for maintenance of cholesterol homeostasis, but also to prevent the accumulation of cholesterol, triglycerides and toxic metabolites as well as violations of the liver and other organs. Enterohepatic circulation of

  20. 4,4,4-trifluoro-3-(indole-3-)butyric acid promotes root elongation in Lactuca sativa independent of ethylene synthesis and pH

    Science.gov (United States)

    Zhang, Nenggang; Hasenstein, Karl H.

    2002-01-01

    We studied the mode of action of 4,4,4-trifluoro-3- (indole-3-) butyric acid (TFIBA), a recently described root growth stimulator, on primary root growth of Lactuca sativa L. seedlings. TFIBA (100 micromoles) promoted elongation of primary roots by 40% in 72 h but inhibited hypocotyl growth by 35%. TFIBA induced root growth was independent of pH. TFIBA did not affect ethylene production, but reduced the inhibitory effect of ethylene on root elongation. TFIBA promoted root growth even in the presence of the ethylene biosynthesis inhibitor L-alpha-(2-aminoethoxyvinyl)glycine. TFIBA and the ethylene-binding inhibitor silver thiosulphate (STS) had a similar effect on root elongation. The results indicate that TFIBA-stimulated root elongation was neither pH-dependent nor related to inhibition of ethylene synthesis, but was possibly related to ethylene action.

  1. Ethylene-auxin interactions regulate lateral root initiation and emergence in Arabidopsis thaliana.

    Science.gov (United States)

    Ivanchenko, Maria G; Muday, Gloria K; Dubrovsky, Joseph G

    2008-07-01

    Plant root systems display considerable plasticity in response to endogenous and environmental signals. Auxin stimulates pericycle cells within elongating primary roots to enter de novo organogenesis, leading to the establishment of new lateral root meristems. Crosstalk between auxin and ethylene in root elongation has been demonstrated, but interactions between these hormones in root branching are not well characterized. We find that enhanced ethylene synthesis, resulting from the application of low concentrations of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), promotes the initiation of lateral root primordia. Treatment with higher doses of ACC strongly inhibits the ability of pericycle cells to initiate new lateral root primordia, but promotes the emergence of existing lateral root primordia: behaviour that is also seen in the eto1 mutation. These effects are correlated with decreased pericycle cell length and increased lateral root primordia cell width. When auxin is applied simultaneously with ACC, ACC is unable to prevent the auxin stimulation of lateral root formation in the root tissues formed prior to ACC exposure. However, in root tissues formed after transfer to ACC, in which elongation is reduced, auxin does not rescue the ethylene inhibition of primordia initiation, but instead increases it by several fold. Mutations that block auxin responses, slr1 and arf7 arf19, render initiation of lateral root primordia insensitive to the promoting effect of low ethylene levels, and mutations that inhibit ethylene-stimulated auxin biosynthesis, wei2 and wei7, reduce the inhibitory effect of higher ethylene levels, consistent with ethylene regulating root branching through interactions with auxin.

  2. GA(3) enhances root responsiveness to exogenous IAA by modulating auxin transport and signalling in Arabidopsis.

    Science.gov (United States)

    Li, Guijun; Zhu, Changhua; Gan, Lijun; Ng, Denny; Xia, Kai

    2015-03-01

    We used auxin-signalling mutants, auxin transport mutants, and auxin-related marker lines to show that exogenously applied GA enhances auxin-induced root inhibition by affecting auxin signalling and transport. Variation in root elongation is valuable when studying the interactions of phytohormones. Auxins influence the biosynthesis and signalling of gibberellins (GAs), but the influence of GAs on auxins in root elongation is poorly understood. This study was conducted to investigate the effect of GA3 on Arabidopsis root elongation in the presence of auxin. Root elongation was inhibited in roots treated with both IAA and GA3, compared to IAA alone, and the effect was dose dependent. Further experiments showed that GA3 could modulate auxin signalling based on root elongation in auxin-signalling mutants and the expression of auxin-responsive reporters. The GA3-enhanced inhibition of root elongation observed in the wild type was not found in the auxin-signalling mutants tir1-1 and axr1-3. GA3 increased DR5::GUS expression in the root meristem and elongation zones, and IAA2::GUS in the columella. The DR5rev::GFP signal was enhanced in columella cells of the root caps and in the elongation zone in GA3-treated seedling roots. A reduction was observed in the stele of PAC-treated roots. We also examined the effect of GA3 on auxin transport. The enhanced responsiveness caused by GA3 was not observed in the auxin influx mutant aux1-7 or the efflux mutant eir1-1. Additional molecular data demonstrated that GA3 could promote auxin transport via AUX1 and PIN proteins. However, GA3-induced PIN gene expression did not fully explain GA-enhanced PIN protein accumulation. These results suggest that GA3 is involved in auxin-mediated primary root elongation by modulating auxin signalling and transport, and thus enhances root responsiveness to exogenous IAA.

  3. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera

    Directory of Open Access Journals (Sweden)

    Kumar Ramesh R.

    2011-01-01

    Full Text Available Ashwagandha (Withania somnifera is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant and crude fiber content exhibited strong association among them and showed significant positive genotypic correlation with yield. Starch-fiber ratio (SFR, determinant of brittle root texture showed strong negative association with root yield. The total alkaloid content had positive genotypic correlation with root yield. So genetic upgradation should aim at optimum balance between two divergent groups of traits i.e. root yield traits (root morphometric traits and crude fiber content and root textural quality traits (starch content and SFR to develop superior genotypes with better yield and quality.

  4. Root lattices and quasicrystals

    Science.gov (United States)

    Baake, M.; Joseph, D.; Kramer, P.; Schlottmann, M.

    1990-10-01

    It is shown that root lattices and their reciprocals might serve as the right pool for the construction of quasicrystalline structure models. All noncrystallographic symmetries observed so far are covered in minimal embedding with maximal symmetry.

  5. Roots and routes

    DEFF Research Database (Denmark)

    Christensen, Ann-Dorte; Jensen, Sune Qvotrup

    2011-01-01

    This article is about transnational migrants, how they construct belonging to ‘new’ places where they have arrived, and how the feelings of belonging to their places of origin change when they go back. The theoretical part of the article outlines the relationship between migration and belonging...... arguing that there is a dynamic interplay between roots and routes in people's lives. The empirical point of departure is narratives about roots and routes by ethnic minorities settled in Aalborg East, an underprivileged neighbourhood in northern Denmark. One of the main findings is a gap between....... A somewhat paradoxical finding is that it appears to be more difficult for transnational migrants to maintain their roots in the country of origin when they go back than it was to establish new roots in the host country...

  6. Isolation and screening of rhizobia for auxin biosynthesis and growth promotion of mung bean (Vigna radiata L. seedlings under axenic conditions

    Directory of Open Access Journals (Sweden)

    Muhammad Ashfaq Anjum, Zahir Ahmad Zahir, Muhammad Arshad and Muhammad Ashraf

    2011-04-01

    Full Text Available A series of screening experiments to evaluate the effectiveness of rhizobia for producing auxins and improvegrowth and nodulation of mungbean (Vigna radiata L. were carried out under axenic conditions. Forty fouriolatess of rhizobia were isolated using standard procedures. Auxin biosynthesis by these rhizobial isolates wasdetermined in the absence and presence of L-Trp, a physiological precursor of auxins. Rhizobial isolates variedwidely in auxins biosynthesis capabilities. On the basis of auxins biosynthesis, a pouch experiment was conductedfor screening thirty four efficient isolates of rhizobia for the growth promotion of mung bean. Results of pouch studyshowed that inoculation with selected rhizobial isolates increased the root /shoot length, fresh, and dry shoot weightof mung bean up to 33, 59, 71, 148, 107 and 188%, respectively, over untreated control. Further studies are neededunder glasshouse and field conditions for confirmation of these results.

  7. Evidence supporting need satisfaction and frustration as two distinguishable constructs.

    Science.gov (United States)

    Longo, Ylenio; Alcaraz-Ibáñez, Manuel; Sicilia, Alvaro

    2018-02-01

    This paper aims to (1) investigate whether psychological need satisfaction and frustration are distinguishable constructs or part of a single continuum, and (2) to develop and validate the Spanish version of the Need Satisfaction and Frustration Scale (NSFS). Confirmatory factor analysis (CFA) and exploratory structural equation models (ESEM) were tested using three samples ( N total = 959). In all samples, a CFA model specifying satisfaction and frustration of each psychological need as distinguishable constructs fit the data better than models specifying them as part of a continuum, even after including method corrections (CFA) or cross-loadings (ESEM). Scale score reliabilities were adequate only when the satisfaction and frustration of each need were treated as distinguishable constructs. The paper provides strong support for specifying need satisfaction and frustration as distinguishable but correlated constructs, as well as adequate evidence of dimensionality, reliability and criterion validity for the Spanish version of the NSFS.

  8. Charles L. Brewer Award for Distinguished Teaching of Psychology

    Science.gov (United States)

    American Psychologist, 2007

    2007-01-01

    This article announces the 2007 recipient of the Charles L. Brewer Award for Distinguished Teaching of Psychology: Baron Perlman. A brief biography, highlighting areas of special focus in Perlman's work, is provided.

  9. Development of children's ability to distinguish sarcasm and verbal irony.

    Science.gov (United States)

    Glenwright, Melanie; Pexman, Penny M

    2010-03-01

    Adults distinguish between ironic remarks directed at targets (sarcasm) and ironic remarks not directed at specific targets. We investigated the development of children's appreciation for this distinction by presenting these speech acts to 71 five- to six-year-olds and 71 nine- to ten-year-olds. Five- to six-year-olds were beginning to understand the non-literal meanings of sarcastic speakers and ironic speakers but did not distinguish ironic and sarcastic speakers' intentions. Nine- to ten-year-olds were more accurate at understanding sarcastic and ironic speakers and they distinguished these speakers' intentions, rating sarcastic criticisms as more 'mean' than ironic criticisms. These results show that children can determine the non-literal meanings of sarcasm and irony by six years of age but do not distinguish the pragmatic purposes of these speech acts until later in middle childhood.

  10. Organic Milk Quality in the Netherlands : Distinguishable from conventional milk?

    NARCIS (Netherlands)

    Hospers-Brands, A.J.T.M.; Burgt, van der G.J.H.M.

    2009-01-01

    Recent studies have indicated possible positive interactions between organic animal production and, particularly, and various vitamins. As possible distinguishing quality parameters for organic milk, the differences between organic and conventional milk in Netherlands for fatty acid composition and

  11. Identical Distinguishable Gas Particles in the Real World

    Indian Academy of Sciences (India)

    IAS Admin

    fuzzy quantum particles.' In this case, the overlap of their wavefunctions during collisional mixing makes it impos- sible to distinguish individual particles. Any gas of identical quantum particles will necessarily be indistinguishable, even if it.

  12. Cold storage of rooted and non-rooted carnation cuttings

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... The specific objectives of this study were to evaluate the effect of storage duration on the survival rate of rooted cuttings and to determine the rooting and survival rates of non-rooted cuttings for two standard carnation cultivars (that is., Dianora and Vittorio). The survival rates of rooted cuttings showed ...

  13. Entropic Lower Bound for Distinguishability of Quantum States

    Directory of Open Access Journals (Sweden)

    Seungho Yang

    2015-01-01

    Full Text Available For a system randomly prepared in a number of quantum states, we present a lower bound for the distinguishability of the quantum states, that is, the success probability of determining the states in the form of entropy. When the states are all pure, acquiring the entropic lower bound requires only the density operator and the number of the possible states. This entropic bound shows a relation between the von Neumann entropy and the distinguishability.

  14. Imaging Prostatic Lipids to Distinguish Aggressive Prostate Cancer

    Science.gov (United States)

    2016-12-01

    Award Number: W81XWH-12-1-0168 TITLE: Imaging Prostatic Lipids to Distinguish Aggressive Prostate Cancer PRINCIPAL INVESTIGATOR: Jackilen...Imaging Prostatic Lipids to Distinguish Aggressive Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-12-1-0168 5c. PROGRAM ELEMENT NUMBER...overexpression, lipid accumulation, lipid oxidation, and tumor aggressiveness will be explored using metabolomics. Plan: Employing a cross-sectional

  15. Relationships between root diameter, root length and root branching along lateral roots in adult, field-grown maize.

    Science.gov (United States)

    Wu, Qian; Pagès, Loïc; Wu, Jie

    2016-03-01

    Root diameter, especially apical diameter, plays an important role in root development and function. The variation in diameter between roots, and along roots, affects root structure and thus the root system's overall foraging performance. However, the effect of diameter variation on root elongation, branching and topological connections has not been examined systematically in a population of high-order roots, nor along the roots, especially for mature plants grown in the field. A method combining both excavation and analysis was applied to extract and quantify root architectural traits of adult, field-grown maize plants. The relationships between root diameter and other root architectural characteristics are analysed for two maize cultivars. The basal diameter of the lateral roots (orders 1-3) was highly variable. Basal diameter was partly determined by the diameter of the bearing segment. Basal diameter defined a potential root length, but the lengths of most roots fell far short of this. This was explained partly by differences in the pattern of diameter change along roots. Diameter tended to decrease along most roots, with the steepness of the gradient of decrease depending on basal diameter. The longest roots were those that maintained (or sometimes increased) their diameters during elongation. The branching density (cm(-1)) of laterals was also determined by the diameter of the bearing segment. However, the location of this bearing segment along the mother root was also involved - intermediate positions were associated with higher densities of laterals. The method used here allows us to obtain very detailed records of the geometry and topology of a complex root system. Basal diameter and the pattern of diameter change along a root were associated with its final length. These relationships are especially useful in simulations of root elongation and branching in source-sink models. © The Author 2016. Published by Oxford University Press on behalf of the Annals

  16. Towards Novel Techniques for Root Phenotyping Using GPR

    Science.gov (United States)

    Kobylinski, C.; Neely, H.; Everett, M. E.; Hays, D. B.; Lewis, K.

    2017-12-01

    The ability to phenotype roots in situ would provide information for carbon sequestration potential through increased root mass, possible water-seeking strategies by plants, and generate data for plant breeders. One technique for root phenotyping is to measure differences in soil moisture and use this data to infer root presence or absence. Current technologies for soil moisture detection include electromagnetic induction and neutron moisture meters; however, ground penetrating radar (GPR) has been suggested to monitor root phenotypes. The objective of this study is to use GPR as a novel technique for detecting roots and classifying root phenotypes based on the detection of differences in dielectric permittivity in response to changes in soil water content. The study will be conducted at two sites in Texas: Thrall, TX (Burleson clay) and Lubbock, TX (Olton clay loam). Three root types will be investigated: fibrous (grain sorghum), tap root (cowpea), and mixed (9-species). Data will be collected along a 10 m linear transect in each plot with a PulseEkko GPR bi-static unit operating at a radio frequency of 500 MHz. Additionally, an EM38-MK2 survey will be performed along each transect. Soil surface moisture readings will be collected with a ML3 ThetaProbe soil moisture sensor and a neutron moisture meter will be used to obtain soil moisture measurements down to 1.2 m. Measurements will be collected every two weeks throughout the growing season. Soil properties including particle size distribution, cation exchange capacity, and bulk density will also be measured. GPR's ability to distinguish root types across soils will be assessed.

  17. Adaptation of root growth to increased ambient temperature requires auxin and ethylene coordination in Arabidopsis

    DEFF Research Database (Denmark)

    Fei, Qionghui; Wei, Shaodong; Zhou, Zhaoyang

    2017-01-01

    Key message: A fresh look at the roles of auxin, ethylene, and polar auxin transport during the plant root growth response to warmer ambient temperature (AT). Abstract: The ambient temperature (AT) affects plant growth and development. Plants can sense changes in the AT, but how this change......-naphthaleneacetic acid, but not indole-3-acetic acid (IAA). AUX1, PIN1, and PIN2 are involved in the ckrc1-1 root gravity response under increased AT. Furthermore, CKRC1-dependent auxin biosynthesis was critical for maintaining PIN1, PIN2, and AUX1 expression at elevated temperatures. Ethylene was also involved...... in this regulation through the ETR1 pathway. Higher AT can promote CKRC1-dependent auxin biosynthesis by enhancing ETR1-mediated ethylene signaling. Our research suggested that the interaction between auxin and ethylene and that the interaction-mediated polar auxin transport play important roles during the plant...

  18. Organization of peripheral nerves and spinal roots of the Atlantic stingray, Dasyatis sabina.

    Science.gov (United States)

    Coggeshall, R E; Leonard, R B; Applebaum, M L; Willis, W D

    1978-01-01

    1. The sizes and numbers of axons in peripheral nerves and spinal roots were investigated in the stingray, Dasyatis sabina. 2. The axons of the dorsal and ventral roots do not mingle in peripheral nerves of this animal as they do in higher vertebrates. Thus, it was usually possible to split the peripheral nerve into two portions, one containing only dorsal root axons, the other containing only ventral root axons. This feature was useful for the analysis of certain aspects of spinal cord organization. 3. The fact that dorsal and ventral root axons were segregated in peripheral nerves enabled us to demonstrate, without experimental surgery, that the central processes of the dorsal root ganglion cells and the proximal ventral root axons were 10-20% narrower, on the average, than the distal processes of the same dorsal root ganglion cells or the distal parts of the same ventral root axons. 4. The stingray is remarkable in having very few unmyelinated axons in the dorsal roots, ventral roots, or peripheral nerves. This paucity of unmyelinated axons distinguishes the Atlantic stingrays from all other vertebrates whose roots and nerves have been examined for unmyelinated fibers. 5. Similar findings were obtained for one spotted eagle ray (Aetobatus narinari) and two cow-nose rays (Rhinoptera bonasus).

  19. A Metabolomic Approach for the Discrimination of Red Ginseng Root Parts and Targeted Validation.

    Science.gov (United States)

    In, Gyo; Seo, Hyun Kyu; Park, Hee-Won; Jang, Kyoung Hwa

    2017-03-15

    Ginsenosides are used as existing markers of red ginseng (RG) quality, and ginsenoside ratios are also indicative of the different components of red ginseng. For the analysis and classification of ginsenoside content, red ginseng was separated into three parts, namely, main roots, lateral roots, and fine roots, and each extract was subjected to ultra-performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-QToF-MS) with multivariate statistical analysis. Principal component analysis (PCA) showed a clear discrimination between the extracts of main roots and fine roots and suggested discrimination markers (four for the main roots and five for the fine roots). The fine root markers were identified as ginsenoside. We identified two markers for the main roots of red ginseng in this study. Moreover, the contents of 22 ginsenosides were analyzed in all three components of red ginseng. Fine roots have the highest protopanaxadiol (PPD)/protopanaxatriol (PPT) ratio. The PPD group of ginsenosides, which is quantitatively dominant in fine roots, clearly distinguishes the main roots from the other parts.

  20. The "Green" Root Beer Laboratory

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2010-01-01

    No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has…

  1. The Biosynthesis of Capuramycin-type Antibiotics

    Science.gov (United States)

    Cai, Wenlong; Goswami, Anwesha; Yang, Zhaoyong; Liu, Xiaodong; Green, Keith D.; Barnard-Britson, Sandra; Baba, Satoshi; Funabashi, Masanori; Nonaka, Koichi; Sunkara, Manjula; Morris, Andrew J.; Spork, Anatol P.; Ducho, Christian; Garneau-Tsodikova, Sylvie; Thorson, Jon S.; Van Lanen, Steven G.

    2015-01-01

    A-500359s, A-503083s, and A-102395 are capuramycin-type nucleoside antibiotics that were discovered using a screen to identify inhibitors of bacterial translocase I, an essential enzyme in peptidoglycan cell wall biosynthesis. Like the parent capuramycin, A-500359s and A-503083s consist of three structural components: a uridine-5′-carboxamide (CarU), a rare unsaturated hexuronic acid, and an aminocaprolactam, the last of which is substituted by an unusual arylamine-containing polyamide in A-102395. The biosynthetic gene clusters for A-500359s and A-503083s have been reported, and two genes encoding a putative non-heme Fe(II)-dependent α-ketoglutarate:UMP dioxygenase and an l-Thr:uridine-5′-aldehyde transaldolase were uncovered, suggesting that C–C bond formation during assembly of the high carbon (C6) sugar backbone of CarU proceeds from the precursors UMP and l-Thr to form 5′-C-glycyluridine (C7) as a biosynthetic intermediate. Here, isotopic enrichment studies with the producer of A-503083s were used to indeed establish l-Thr as the direct source of the carboxamide of CarU. With this knowledge, the A-102395 gene cluster was subsequently cloned and characterized. A genetic system in the A-102395-producing strain was developed, permitting the inactivation of several genes, including those encoding the dioxygenase (cpr19) and transaldolase (cpr25), which abolished the production of A-102395, thus confirming their role in biosynthesis. Heterologous production of recombinant Cpr19 and CapK, the transaldolase homolog involved in A-503083 biosynthesis, confirmed their expected function. Finally, a phosphotransferase (Cpr17) conferring self-resistance was functionally characterized. The results provide the opportunity to use comparative genomics along with in vivo and in vitro approaches to probe the biosynthetic mechanism of these intriguing structures. PMID:25855790

  2. Heme biosynthesis and its regulation : Toward understanding and improvement of heme biosynthesis in filamentous fungi.

    NARCIS (Netherlands)

    S. de Weert; P.J. Punt; Christien Lokman; C.A. van den Hondel; A.C. Franken; A.F. Ram

    2011-01-01

    Heme biosynthesis in fungal host strains has acquired considerable interest in relation to the production of secreted heme-containing peroxidases. Class II peroxidase enzymes have been suggested as eco-friendly replacements of polluting chemical processes in industry. These peroxidases are naturally

  3. Heme biosynthesis and its regulation: Towards understanding and improvement of heme biosynthesis in filamentous fungi

    NARCIS (Netherlands)

    Franken, A.C.W.; Lokman, B.C.; Ram, A.F.J.; Punt, P.J.; Hondel, C.A.M.J.J. van den; Weert, S. de

    2011-01-01

    Heme biosynthesis in fungal host strains has acquired considerable interest in relation to the production of secreted heme-containing peroxidases. Class II peroxidase enzymes have been suggested as eco-friendly replacements of polluting chemical processes in industry. These peroxidases are naturally

  4. Unedoside derivatives in Nuxia and their biosynthesis

    DEFF Research Database (Denmark)

    Jensen, Søren Rosendal; Ravnkilde, Lene; Schripsema, Jan

    1998-01-01

    An investigation of two species of Nuxia showed that this genus is characterized by the presence of the eight-carbon iridoid glucoside unedoside and/or its derivatives. From N. floribunda unedoside, nuxioside (6-O-alpha-L-rhamnopyranosyl-unedoside) and 2 "-acetyl-3 "-cinnamoyl-nuxioside were...... isolated, while from N. oppositifolia 2 "-acetyl-3 "-benzoyl-nuxioside was obtained. Both plants contained verbascoside. The biosynthesis of unedoside in N. floribunda was investigated and deoxyloganic acid was found to be a precursor, similar to wh;lt was found for the eight-carbon iridoids in Thunbergia...

  5. Biosynthesis of Gold Nanoparticles Using Pseudomonas Aeruginosa

    International Nuclear Information System (INIS)

    Abd El-Aziz, M.; Badr, Y.; Mahmoud, M. A.

    2007-01-01

    Pseudomonas aeruginosa were used for extracellular biosynthesis of gold nanoparticles (Au NPs). Consequently, Au NPs were formed due to reduction of gold ion by bacterial cell supernatant of P. aeruginos ATCC 90271, P. aeruginos (2) and P. aeruginos (1). The UV-Vis. and fluorescence spectra of the bacterial as well as chemical prepared Au NPs were recorded. Transmission electron microscopy (TEM) micrograph showed the formation of well-dispersed gold nanoparticles in the range of 15-30 nm. The process of reduction being extracellular and may lead to the development of an easy bioprocess for synthesis of Au NPs

  6. Developing New Antibiotics with Combinatorial Biosynthesis

    Science.gov (United States)

    Pohl, Nicola L.

    2000-11-01

    Polyketide synthases (PKSs), a class of enzymes found in soil bacteria that produce antibiotics such as erythromycin, string together acetate units using basic organic reactions. The manipulation of the sequence of these reactions at the genetic level has resulted in an alteration of the corresponding chemical structure of the antibiotic produced by the bacteria. This process, called combinatorial biosynthesis, allows the generation of many presently unknown complex structures that can be tested for antibacterial activity, thereby contributing to the race against antibiotic-resistant infectious bacteria.

  7. Biosynthesis of silver nanoparticles using Saccharomyces cerevisiae.

    Science.gov (United States)

    Korbekandi, Hassan; Mohseni, Soudabeh; Mardani Jouneghani, Rasoul; Pourhossein, Meraj; Iravani, Siavash

    2016-01-01

    The objectives of this study were the biosynthesis of silver nanoparticles (NPs) by biotransformations using Saccharomyces cerevisiae and analysis of the sizes and shapes of the NPs produced. Dried and freshly cultured S. cerevisiae were used as the biocatalyst. Dried yeast synthesized few NPs, but freshly cultured yeast produced a large amount of them. Silver NPs were spherical, 2-20 nm in diameter, and the NPs with the size of 5.4 nm were the most frequent ones. NPs were seen inside the cells, within the cell membrane, attached to the cell membrane during the exocytosis, and outside of the cells.

  8. An assessment of the role of ethylene in mediating lettuce (Lactuca sativa) root growth at high temperatures.

    Science.gov (United States)

    Qin, L; He, J; Lee, S K; Dodd, I C

    2007-01-01

    Growth of temperate lettuce (Lactuca sativa) plants aeroponically in tropical greenhouses under ambient root-zone temperatures (A-RZTs) exposes roots to temperatures of up to 40 degrees C during the middle of the day, and severely limits root and shoot growth. The role of ethylene in inhibiting growth was investigated with just-germinated (24-h-old) seedlings in vitro, and 10-d-old plants grown aeroponically. Compared with seedlings maintained at 20 degrees C, root elongation in vitro was inhibited by 39% and root diameter increased by 25% under a temperature regime (38 degrees C/24 degrees C for 7 h/17 h) that simulated A-RZT in the greenhouse. The effects on root elongation were partially alleviated by supplying the ethylene biosynthesis inhibitors aminooxyacetic acid (100-500 microM) or aminoisobutyric acid (5-100 microM) to the seedlings. Application of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid to seedlings grown at 20 degrees C mimicked the high temperature effects on root elongation (1 microM) and root diameter (1 mM). Compared with plants grown at a constant 20 degrees C root-zone temperature, A-RZT plants showed decreased stomatal conductance, leaf relative water content, photosynthetic CO(2) assimilation, shoot and root biomass, total root length, the number of root tips, and root surface area, but increased average root diameter. Addition of 10 microM ACC to the nutrient solution of plants grown at a constant 20 degrees C root-zone temperature mimicked the effects of A-RZT on these parameters but did not influence relative water content. Addition of 30 microM aminoisobutyric acid or 100 microM aminooxyacetic acid to the nutrient solution of A-RZT plants increased stomatal conductance and relative water content and decreased average root diameter, but had no effect on other root parameters or root and shoot biomass or photosynthetic CO(2) assimilation. Although ethylene is important in regulating root morphology and elongation at A

  9. Coupling Deep Transcriptome Analysis with Untargeted Metabolic Profiling in Ophiorrhiza pumila to Further the Understanding of the Biosynthesis of the Anti-Cancer Alkaloid Camptothecin and Anthraquinones

    Science.gov (United States)

    Yamazaki, Mami; Mochida, Keiichi; Asano, Takashi; Nakabayashi, Ryo; Chiba, Motoaki; Udomson, Nirin; Yamazaki, Yasuyo; Goodenowe, Dayan B.; Sankawa, Ushio; Yoshida, Takuhiro; Toyoda, Atsushi; Totoki, Yasushi; Sakaki, Yoshiyuki; Góngora-Castillo, Elsa; Buell, C. Robin; Sakurai, Tetsuya; Saito, Kazuki

    2013-01-01

    The Rubiaceae species, Ophiorrhiza pumila, accumulates camptothecin, an anti-cancer alkaloid with a potent DNA topoisomerase I inhibitory activity, as well as anthraquinones that are derived from the combination of the isochorismate and hemiterpenoid pathways. The biosynthesis of these secondary products is active in O. pumila hairy roots yet very low in cell suspension culture. Deep transcriptome analysis was conducted in O. pumila hairy roots and cell suspension cultures using the Illumina platform, yielding a total of 2 Gb of sequence for each sample. We generated a hybrid transcriptome assembly of O. pumila using the Illumina-derived short read sequences and conventional Sanger-derived expressed sequence tag clones derived from a full-length cDNA library constructed using RNA from hairy roots. Among 35,608 non-redundant unigenes, 3,649 were preferentially expressed in hairy roots compared with cell suspension culture. Candidate genes involved in the biosynthetic pathway for the monoterpenoid indole alkaloid camptothecin were identified; specifically, genes involved in post-strictosamide biosynthetic events and genes involved in the biosynthesis of anthraquinones and chlorogenic acid. Untargeted metabolomic analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) indicated that most of the proposed intermediates in the camptothecin biosynthetic pathway accumulated in hairy roots in a preferential manner compared with cell suspension culture. In addition, a number of anthraquinones and chlorogenic acid preferentially accumulated in hairy roots compared with cell suspension culture. These results suggest that deep transcriptome and metabolome data sets can facilitate the identification of genes and intermediates involved in the biosynthesis of secondary products including camptothecin in O. pumila. PMID:23503598

  10. The biosynthesis of sesquiterpene lactones in chicory (Cichorium intybus L.) roots

    OpenAIRE

    Kraker, de, J.W.

    2002-01-01

    Wild chicory(Cichorium intybusL.) is a blue-flowered composite plant that has spread all over the world from the Mediterranean. Sprouts of chicory var.foliosumHegi that are grown in the dark became popula...

  11. Transcriptional regulation of chlorogenic acid biosynthesis in carrot root slices exposed to UV-B light

    Science.gov (United States)

    Orange carrots are well known for their nutritional value as producers of ß-carotene, a Vitamin A precursor. Lesser known, is their ability to accumulate antioxidants such as chlorogenic acid. Chlorogenic acid is produced through the same biosynthetic pathway that produces lignins, anthocyanins, f...

  12. The biosynthesis of sesquiterpene lactones in chicory (Cichorium intybus L.) roots

    NARCIS (Netherlands)

    Kraker, de J.W.

    2002-01-01

    Wild chicory(Cichorium intybusL.) is a blue-flowered composite plant that has spread all over the world from the Mediterranean. Sprouts

  13. Characterization of two TT2-type MYB transcription factors regulating proanthocyanidin biosynthesis in tetraploid cotton, Gossypium hirsutum.

    Science.gov (United States)

    Lu, Nan; Roldan, Marissa; Dixon, Richard A

    2017-08-01

    Two TT2-type MYB transcription factors identified from tetraploid cotton are involved in regulating proanthocyanidin biosynthesis, providing new strategies for engineering condensed tannins in crops. Proanthocyanidins (PAs), also known as condensed tannins, are important secondary metabolites involved in stress resistance in plants, and are health supplements that help to reduce cholesterol levels. As one of the most widely grown crops in the world, cotton provides the majority of natural fabrics and is a supplemental food for ruminant animals. The previous studies have suggested that PAs present in cotton are a major contributor to fiber color. However, the biosynthesis of PAs in cotton still remains to be elucidated. AtTT2 (transparent testa 2) is a MYB family transcription factor from Arabidopsis that initiates the biosynthesis of PAs by inducing the expression of multiple genes in the pathway. In this study, we isolated two R2R3-type MYB transcription factors from Gossypium hirsutum that are homologous to AtTT2. Expression analysis showed that both genes were expressed at different levels in various cotton tissues, including leaf, seed coat, and fiber. Protoplast transactivation assays revealed that these two GhMYBs were able to activate promoters of genes encoding enzymes in the PA biosynthesis pathway, namely anthocyanidin reductase and leucoanthocyanidin reductase. Complementation experiments showed that both of the GhMYBs were able to recover the transparent testa seed coat phenotype of the Arabidopsis tt2 mutant by restoring PA biosynthesis. Ectopic expression of either of the two GhMYBs in Medicago truncatula hairy roots increased the contents of anthocyanins and PAs compared to control lines expressing the GUS gene, and expression levels of MtDFR, MtLAR, and MtANR were also elevated in lines expressing GhMYBs. Together, these data provide new insights into engineering condensed tannins in cotton.

  14. Fine-tuning by strigolactones of root response to low phosphate.

    Science.gov (United States)

    Kapulnik, Yoram; Koltai, Hinanit

    2016-03-01

    Strigolactones are plant hormones that regulate the development of different plant parts. In the shoot, they regulate axillary bud outgrowth and in the root, root architecture and root-hair length and density. Strigolactones are also involved with communication in the rhizosphere, including enhancement of hyphal branching of arbuscular mycorrhizal fungi. Here we present the role and activity of strigolactones under conditions of phosphate deprivation. Under these conditions, their levels of biosynthesis and exudation increase, leading to changes in shoot and root development. At least for the latter, these changes are likely to be associated with alterations in auxin transport and sensitivity. On the other hand, strigolactones may positively affect plant-mycorrhiza interactions and thereby promote phosphate acquisition by the plant. Strigolactones may be a way for plants to fine-tune their growth pattern under phosphate deprivation. © 2015 Institute of Botany, Chinese Academy of Sciences.

  15. Root system architecture in Arabidopsis grown in culture is regulated by sucrose uptake in the aerial tissues.

    Science.gov (United States)

    Macgregor, Dana R; Deak, Karen I; Ingram, Paul A; Malamy, Jocelyn E

    2008-10-01

    This article presents a detailed model for the regulation of lateral root formation in Arabidopsis thaliana seedlings grown in culture. We demonstrate that direct contact between the aerial tissues and sucrose in the growth media is necessary and sufficient to promote emergence of lateral root primordia from the parent root. Mild osmotic stress is perceived by the root, which then sends an abscisic acid-dependent signal that causes a decrease in the permeability of aerial tissues; this reduces uptake of sucrose from the culture media, which leads to a repression of lateral root formation. Osmotic repression of lateral root formation in culture can be overcome by mutations that cause the cuticle of a plant's aerial tissues to become more permeable. Indeed, we report here that the previously described lateral root development2 mutant overcomes osmotic repression of lateral root formation because of a point mutation in Long Chain Acyl-CoA Synthetase2, a gene essential for cutin biosynthesis. Together, our findings (1) impact the interpretation of experiments that use Arabidopsis grown in culture to study root system architecture; (2) identify sucrose as an unexpected regulator of lateral root formation; (3) demonstrate mechanisms by which roots communicate information to aerial tissues and receive information in turn; and (4) provide insights into the regulatory pathways that allow plants to be developmentally plastic while preserving the essential balance between aboveground and belowground organs.

  16. Isoprenoid Biosynthesis Inhibitors Targeting Bacterial Cell Growth.

    Science.gov (United States)

    Desai, Janish; Wang, Yang; Wang, Ke; Malwal, Satish R; Oldfield, Eric

    2016-10-06

    We synthesized potential inhibitors of farnesyl diphosphate synthase (FPPS), undecaprenyl diphosphate synthase (UPPS), or undecaprenyl diphosphate phosphatase (UPPP), and tested them in bacterial cell growth and enzyme inhibition assays. The most active compounds were found to be bisphosphonates with electron-withdrawing aryl-alkyl side chains which inhibited the growth of Gram-negative bacteria (Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa) at ∼1-4 μg mL -1 levels. They were found to be potent inhibitors of FPPS; cell growth was partially "rescued" by the addition of farnesol or overexpression of FPPS, and there was synergistic activity with known isoprenoid biosynthesis pathway inhibitors. Lipophilic hydroxyalkyl phosphonic acids inhibited UPPS and UPPP at micromolar levels; they were active (∼2-6 μg mL -1 ) against Gram-positive but not Gram-negative organisms, and again exhibited synergistic activity with cell wall biosynthesis inhibitors, but only indifferent effects with other inhibitors. The results are of interest because they describe novel inhibitors of FPPS, UPPS, and UPPP with cell growth inhibitory activities as low as ∼1-2 μg mL -1 . © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. BIOSYNTHESIS AND PROPERTIES OF ANTIBIOTIC BATUMIN

    Directory of Open Access Journals (Sweden)

    V. V. Klochko

    2014-12-01

    Full Text Available Biosynthesis of antistaphylococcal antibiotic batumin under periodic conditions of Pseudomonas batumici growth has been studied. Antibiotic synthesis in fermenter occurred across the culture growth and achieved its maximal value after 50–55 hours. The active oxygen utilization by the producing strain was observed during 20–55 hours of fermentation with maximum after 40–45 hours. Antibiotic yield was 175–180 mg/l and depended on intensity of aeration. contrast to «freshly isolated» antibiotic after fermentation the long-term kept batumin has shown two identical by molecular mass peaks according to the chromato-mass spectrometric analysis. Taking into account of batumin molecule structure the conclusion has been made that the most probable isomerization type is keto-enolic tautomerism. At the same time batumin is diastereoisomer of kalimantacin A which has the same chemical structure. The optic rotation angle is [α]d25 = +56.3° for kalimantacin and [α]d25 = –13.5° for batumin. The simultaneous P. batumici growth and antibiotic biosynthesis and the ability of this molecule to optical isomerisation and keto-enolic forms formation allow us to suppose that batumin plays a certain role in metabolism of the producing strain.

  18. Essences in Metabolic Engineering of Lignan Biosynthesis

    Directory of Open Access Journals (Sweden)

    Honoo Satake

    2015-05-01

    Full Text Available Lignans are structurally and functionally diverse phytochemicals biosynthesized in diverse plant species and have received wide attentions as leading compounds of novel drugs for tumor treatment and healthy diets to reduce of the risks of lifestyle-related non-communicable diseases. However, the lineage-specific distribution and the low-amount of production in natural plants, some of which are endangered species, hinder the efficient and stable production of beneficial lignans. Accordingly, the development of new procedures for lignan production is of keen interest. Recent marked advances in the molecular and functional characterization of lignan biosynthetic enzymes and endogenous and exogenous factors for lignan biosynthesis have suggested new methods for the metabolic engineering of lignan biosynthesis cascades leading to the efficient, sustainable, and stable lignan production in plants, including plant cell/organ cultures. Optimization of light conditions, utilization of a wide range of elicitor treatments, and construction of transiently gene-transfected or transgenic lignan-biosynthesizing plants are mainly being attempted. This review will present the basic and latest knowledge regarding metabolic engineering of lignans based on their biosynthetic pathways and biological activities, and the perspectives in lignan production via metabolic engineering.

  19. Benzylisoquinoline alkaloid biosynthesis in opium poppy.

    Science.gov (United States)

    Beaudoin, Guillaume A W; Facchini, Peter J

    2014-07-01

    Opium poppy (Papaver somniferum) is one of the world's oldest medicinal plants and remains the only commercial source for the narcotic analgesics morphine, codeine and semi-synthetic derivatives such as oxycodone and naltrexone. The plant also produces several other benzylisoquinoline alkaloids with potent pharmacological properties including the vasodilator papaverine, the cough suppressant and potential anticancer drug noscapine and the antimicrobial agent sanguinarine. Opium poppy has served as a model system to investigate the biosynthesis of benzylisoquinoline alkaloids in plants. The application of biochemical and functional genomics has resulted in a recent surge in the discovery of biosynthetic genes involved in the formation of major benzylisoquinoline alkaloids in opium poppy. The availability of extensive biochemical genetic tools and information pertaining to benzylisoquinoline alkaloid metabolism is facilitating the study of a wide range of phenomena including the structural biology of novel catalysts, the genomic organization of biosynthetic genes, the cellular and sub-cellular localization of biosynthetic enzymes and a variety of biotechnological applications. In this review, we highlight recent developments and summarize the frontiers of knowledge regarding the biochemistry, cellular biology and biotechnology of benzylisoquinoline alkaloid biosynthesis in opium poppy.

  20. Molecular Regulation of Antibiotic Biosynthesis in Streptomyces

    Science.gov (United States)

    Liu, Gang; Chandra, Govind; Niu, Guoqing

    2013-01-01

    SUMMARY Streptomycetes are the most abundant source of antibiotics. Typically, each species produces several antibiotics, with the profile being species specific. Streptomyces coelicolor, the model species, produces at least five different antibiotics. We review the regulation of antibiotic biosynthesis in S. coelicolor and other, nonmodel streptomycetes in the light of recent studies. The biosynthesis of each antibiotic is specified by a large gene cluster, usually including regulatory genes (cluster-situated regulators [CSRs]). These are the main point of connection with a plethora of generally conserved regulatory systems that monitor the organism's physiology, developmental state, population density, and environment to determine the onset and level of production of each antibiotic. Some CSRs may also be sensitive to the levels of different kinds of ligands, including products of the pathway itself, products of other antibiotic pathways in the same organism, and specialized regulatory small molecules such as gamma-butyrolactones. These interactions can result in self-reinforcing feed-forward circuitry and complex cross talk between pathways. The physiological signals and regulatory mechanisms may be of practical importance for the activation of the many cryptic secondary metabolic gene cluster pathways revealed by recent sequencing of numerous Streptomyces genomes. PMID:23471619

  1. Biosynthesis of nanoparticles using microbes- a review.

    Science.gov (United States)

    Hulkoti, Nasreen I; Taranath, T C

    2014-09-01

    The biosynthesis of nanoparticles by microorganism is a green and eco-friendly technology. This review focuses on the use of consortium of diverse microorganisms belonging to both prokaryotes and eukaryotes for the synthesis of metallic nanoparticles viz. silver, gold, platinum, zirconium, palladium, iron, cadmium and metal oxides such as titanium oxide, zinc oxide, etc. These microorganisms include bacteria, actinomycetes, fungi and algae. The synthesis of nanoparticles may be intracellular or extracellular. The several workers have reported that NADH dependent nitrate reductase enzyme plays a vital role in the conversion of metallic ions to nanoparticles. The FTIR study reveals that diverse biomolecules viz. carboxyl group, primary and secondary amines, amide I, II, and III bands etc serve as a tool for bioreduction and capping agents there by offering stability to particles by preventing agglomeration and growth. The size and shape of the nanoparticles vary with the organism employed and conditions employed during the synthesis which included pH, temperature and substrate concentration. The microorganisms provide diverse environment for biosynthesis of nanoparticles. These particles are safe and eco-friendly with a lot of applications in medicine, agriculture, cosmetic industry, drug delivery and biochemical sensors. The challenges for redressal include optimal production and minimal time to obtain desired size and shape, to enhance the stability of nanoparticles and optimization of specific microorganisms for specific application. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Biological characteristics of Bacillus amyloliquefaciens AK-0 and suppression of ginseng root rot caused by Cylindrocarpon destructans.

    Science.gov (United States)

    Kim, Y S; Balaraju, K; Jeon, Y H

    2017-01-01

    The effect of Bacillus amyloliquefaciens AK-0 (AK-0) on ginseng root rot disease caused by Cylindrocarpon destructans was investigated. From 190 ginseng rhizosphere bacteria, AK-0 was selected for further analysis; its morphological characteristics were investigated by microscopy. AK-0 was identified as B. amyloliquefaciens using the Biolog system, 16S rRNA gene sequence analysis and examination of morphological and biochemical characteristics. Bacterial population and media optimization were estimated by the bacterial growth curve. The number of AK-0 cells was relatively higher in brain-heart infusion (BHI) medium than in other media. The potential antifungal effect of AK-0 culture filtrate on the in vitro conidial germination of C. destructans and root rot development on root discs and 4-year-old ginseng roots were assessed. Polymerase chain reaction (PCR) analysis of antibiotic biosynthesis gene expression suggested that the release of antibiotic compounds is involved in the antifungal effect of AK-0 and the suppression of ginseng root rot. These results indicate that the CF of AK-0 has antifungal effects on fungal pathogens of ginseng, resulting in the suppression of root rot disease caused by C. destructans. AK-0 is a potential source of novel bioactive metabolites. AK-0 CF exhibited antifungal effects against C. destructans on ginseng roots. PCR analysis indicated that the AK-0 harbours genes involved in the biosynthesis of antimicrobial compounds. © 2016 The Society for Applied Microbiology.

  3. Metabolic shift from withasteroid formation to phenylpropanoid accumulation in cryptogein-cotransformed hairy roots of Withania somnifera (L.) Dunal.

    Science.gov (United States)

    Sil, Bipradut; Mukherjee, Chiranjit; Jha, Sumita; Mitra, Adinpunya

    2015-07-01

    Cotransformed hairy roots containing a gene that encodes a fungal elicitor protein, β-cryptogein, were established in Withania somnifera, a medicinal plant widely used in Indian systems of medicine. To find out whether β-cryptogein protein endogenously elicits the pathway of withasteroid biosynthesis, withaferin A and withanolide A contents along with transcript accumulation of farnesyl pyrophosphate (FPP) synthase, 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR), and sterol glycosyltransferase (SGT) were analyzed in both cryptogein-cotransformed and normal hairy roots of W. somnifera. It was observed that the withaferin A and withanolide A contents were drastically higher in normal hairy roots than cryptogein-cotransformed ones. Similar trends were also observed on the levels of transcript accumulation. Subsequently, the enzyme activity of phenylalanine ammonia lyase (PAL), one of the key enzymes of phenylpropanoid pathway, was measured in both cryptogein-cotransformed and normal hairy roots of W. somnifera along with the levels of PAL transcript accumulation. Upliftment of PAL activity was observed in cryptogein-cotransformed hairy roots as compared to the normal ones, and the PAL expression also reflected a similar trend, i.e., enhanced expression in the cryptogein-cotransformed lines. Upliftment of wall-bound ferulic acid accumulation was also observed in the cryptogein-cotransformed lines, as compared to normal hairy root lines. Thus, the outcome of the above studies suggests a metabolic shift from withanolide accumulation to phenylpropanoid biosynthesis in cryptogein-cotransformed hairy roots of W. somnifera.

  4. Rare cause of post-squalene disorder of cholesterol biosynthesis ...

    African Journals Online (AJOL)

    Errors of cholesterol biosynthesis represent a heterogeneous group of metabolic disorders. The aim of the authors of this article is to present a case of a patient with typical symptoms of a rare post-squalene disorder of cholesterol biosynthesis, its diagnostics and progress in neonatal period. The differential diagnosis of a ...

  5. Rapid biosynthesis of cadmium sulfide (CdS) nanoparticles using ...

    African Journals Online (AJOL)

    Rapid biosynthesis of cadmium sulfide (CdS) nanoparticles using culture supernatants of Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633 and Lactobacillus ... The process of extracellular and fast biosynthesis may help in the development of an easy and eco-friendly route for the synthesis of CdS nanoparticles.

  6. Ant trail pheromone biosynthesis is triggered by a neuropeptide hormone.

    Directory of Open Access Journals (Sweden)

    Man-Yeon Choi

    Full Text Available Our understanding of insect chemical communication including pheromone identification, synthesis, and their role in behavior has advanced tremendously over the last half-century. However, endocrine regulation of pheromone biosynthesis has progressed slowly due to the complexity of direct and/or indirect hormonal activation of the biosynthetic cascades resulting in insect pheromones. Over 20 years ago, a neurohormone, pheromone biosynthesis activating neuropeptide (PBAN was identified that stimulated sex pheromone biosynthesis in a lepidopteran moth. Since then, the physiological role, target site, and signal transduction of PBAN has become well understood for sex pheromone biosynthesis in moths. Despite that PBAN-like peptides (∼200 have been identified from various insect Orders, their role in pheromone regulation had not expanded to the other insect groups except for Lepidoptera. Here, we report that trail pheromone biosynthesis in the Dufour's gland (DG of the fire ant, Solenopsis invicta, is regulated by PBAN. RNAi knock down of PBAN gene (in subesophageal ganglia or PBAN receptor gene (in DG expression inhibited trail pheromone biosynthesis. Reduced trail pheromone was documented analytically and through a behavioral bioassay. Extension of PBAN's role in pheromone biosynthesis to a new target insect, mode of action, and behavioral function will renew research efforts on the involvement of PBAN in pheromone biosynthesis in Insecta.

  7. Biosynthesis and chemical transformation of benzoxazinoids in rye during seed germination and the identification of a rye Bx6-like gene

    DEFF Research Database (Denmark)

    Tanwir, Fariha; Dionisio, Giuseppe; B. Adhikari, Khem

    2017-01-01

    forms of benzoxazinoids accumulated in roots rather than in shoots during seedling development, in particular reaching high levels of HMBOA-glc in roots. Chemical profiles of benzoxazinoid accumulation in the developing seedling reflected the combined effects of de novo biosynthesis of the compounds...... development in rye. Our results showed that ScBx genes had highest levels of expression at 24–30 h after germination, followed by a decrease at later stages. For ScBx1-ScBx5 genes expression was higher in shoots compared with root tissues and vice versa for ScBx6-like gene transcripts. Moreover, methylated...... as well as the turnover of compounds either pre-stored in the embryo or de novo biosynthesized. Bioinformatic analysis, together with the differential distribution of ScBx6-like transcripts in root and shoot tissues, suggested the presence of a ZmBx6 homolog encoding a 2-oxoglutarate dependent...

  8. Nitric oxide mediates strigolactone signaling in auxin and ethylene-sensitive lateral root formation in sunflower seedlings.

    Science.gov (United States)

    Bharti, Niharika; Bhatla, Satish C

    2015-01-01

    Strigolactones (SLs) play significant role in shaping root architecture whereby auxin-SL crosstalk has been observed in SL-mediated responses of primary root elongation, lateral root formation and adventitious root (AR) initiation. Whereas GR24 (a synthetic strigolactone) inhibits LR and AR formation, the effect of SL biosynthesis inhibitor (fluridone) is just the opposite (root proliferation). Naphthylphthalamic acid (NPA) leads to LR proliferation but completely inhibits AR development. The diffusive distribution of PIN1 in the provascular cells in the differentiating zone of the roots in response to GR24, fluridone or NPA treatments further indicates the involvement of localized auxin accumulation in LR development responses. Inhibition of LR formation by GR24 treatment coincides with inhibition of ACC synthase activity. Profuse LR development by fluridone and NPA treatments correlates with enhanced [Ca(2+)]cyt in the apical region and differentiating zones of LR, indicating a critical role of [Ca(2+)] in LR development in response to the coordinated action of auxins, ethylene and SLs. Significant enhancement of carotenoid cleavage dioxygenase (CCD) activity (enzyme responsible for SL biosynthesis) in tissue homogenates in presence of cPTIO (NO scavenger) indicates the role of endogenous NO as a negative modulator of CCD activity. Differences in the spatial distribution of NO in the primary and lateral roots further highlight the involvement of NO in SL-modulated root morphogenesis in sunflower seedlings. Present work provides new report on the negative modulation of SL biosynthesis through modulation of CCD activity by endogenous nitric oxide during SL-modulated LR development.

  9. Functional identification of valerena-1,10-diene synthase, a terpene synthase catalyzing a unique chemical cascade in the biosynthesis of biologically active sesquiterpenes in Valeriana officinalis.

    Science.gov (United States)

    Yeo, Yun-Soo; Nybo, S Eric; Chittiboyina, Amar G; Weerasooriya, Aruna D; Wang, Yan-Hong; Góngora-Castillo, Elsa; Vaillancourt, Brieanne; Buell, C Robin; DellaPenna, Dean; Celiz, Mary Dawn; Jones, A Daniel; Wurtele, Eve Syrkin; Ransom, Nick; Dudareva, Natalia; Shaaban, Khaled A; Tibrewal, Nidhi; Chandra, Suman; Smillie, Troy; Khan, Ikhlas A; Coates, Robert M; Watt, David S; Chappell, Joe

    2013-02-01

    Valerian is an herbal preparation from the roots of Valeriana officinalis used as an anxiolytic and sedative and in the treatment of insomnia. The biological activities of valerian are attributed to valerenic acid and its putative biosynthetic precursor valerenadiene, sesquiterpenes, found in V. officinalis roots. These sesquiterpenes retain an isobutenyl side chain whose origin has been long recognized as enigmatic because a chemical rationalization for their biosynthesis has not been obvious. Using recently developed metabolomic and transcriptomic resources, we identified seven V. officinalis terpene synthase genes (VoTPSs), two that were functionally characterized as monoterpene synthases and three that preferred farnesyl diphosphate, the substrate for sesquiterpene synthases. The reaction products for two of the sesquiterpene synthases exhibiting root-specific expression were characterized by a combination of GC-MS and NMR in comparison to the terpenes accumulating in planta. VoTPS7 encodes for a synthase that biosynthesizes predominately germacrene C, whereas VoTPS1 catalyzes the conversion of farnesyl diphosphate to valerena-1,10-diene. Using a yeast expression system, specific labeled [(13)C]acetate, and NMR, we investigated the catalytic mechanism for VoTPS1 and provide evidence for the involvement of a caryophyllenyl carbocation, a cyclobutyl intermediate, in the biosynthesis of valerena-1,10-diene. We suggest a similar mechanism for the biosynthesis of several other biologically related isobutenyl-containing sesquiterpenes.

  10. Functional Identification of Valerena-1,10-diene Synthase, a Terpene Synthase Catalyzing a Unique Chemical Cascade in the Biosynthesis of Biologically Active Sesquiterpenes in Valeriana officinalis*

    Science.gov (United States)

    Yeo, Yun-Soo; Nybo, S. Eric; Chittiboyina, Amar G.; Weerasooriya, Aruna D.; Wang, Yan-Hong; Góngora-Castillo, Elsa; Vaillancourt, Brieanne; Buell, C. Robin; DellaPenna, Dean; Celiz, Mary Dawn; Jones, A. Daniel; Wurtele, Eve Syrkin; Ransom, Nick; Dudareva, Natalia; Shaaban, Khaled A.; Tibrewal, Nidhi; Chandra, Suman; Smillie, Troy; Khan, Ikhlas A.; Coates, Robert M.; Watt, David S.; Chappell, Joe

    2013-01-01

    Valerian is an herbal preparation from the roots of Valeriana officinalis used as an anxiolytic and sedative and in the treatment of insomnia. The biological activities of valerian are attributed to valerenic acid and its putative biosynthetic precursor valerenadiene, sesquiterpenes, found in V. officinalis roots. These sesquiterpenes retain an isobutenyl side chain whose origin has been long recognized as enigmatic because a chemical rationalization for their biosynthesis has not been obvious. Using recently developed metabolomic and transcriptomic resources, we identified seven V. officinalis terpene synthase genes (VoTPSs), two that were functionally characterized as monoterpene synthases and three that preferred farnesyl diphosphate, the substrate for sesquiterpene synthases. The reaction products for two of the sesquiterpene synthases exhibiting root-specific expression were characterized by a combination of GC-MS and NMR in comparison to the terpenes accumulating in planta. VoTPS7 encodes for a synthase that biosynthesizes predominately germacrene C, whereas VoTPS1 catalyzes the conversion of farnesyl diphosphate to valerena-1,10-diene. Using a yeast expression system, specific labeled [13C]acetate, and NMR, we investigated the catalytic mechanism for VoTPS1 and provide evidence for the involvement of a caryophyllenyl carbocation, a cyclobutyl intermediate, in the biosynthesis of valerena-1,10-diene. We suggest a similar mechanism for the biosynthesis of several other biologically related isobutenyl-containing sesquiterpenes. PMID:23243312

  11. Transcriptome profiling of sweetpotato tuberous roots during low temperature storage.

    Science.gov (United States)

    Ji, Chang Yoon; Chung, Won-Hyong; Kim, Ho Soo; Jung, Won Yong; Kang, Le; Jeong, Jae Cheol; Kwak, Sang-Soo

    2017-03-01

    Sweetpotato [Ipomoea batatas (L.) Lam] is a globally important root crop with high industrial value. However, because sweetpotato tuberous roots undergo chilling injuries that negatively affect their quality at temperatures below 10 °C, postharvest damage during the winter season is a major constraint for industrialization. To understand chilling injury response during postharvest low temperature storage, we used next-generation sequencing technology to comprehensive analyze the transcriptome of tuberous roots stored at optimal (13 °C) or low temperature (4 °C) for 6 weeks. From nine cDNA libraries, we produced 298,765,564 clean reads, which were de novo assembled into 58,392 unigenes with an average length of 1100 bp. A total of 3216 differentially expressed genes (DEGs) were detected and categorized into six clusters, of which clusters 2, 4, and 5 (1464 DEGs) were up-regulated under low temperature. The genes in these three clusters are involved in biosynthesis of unsaturated fatty acids, pathogen defense, and phenylalanine metabolism. By contrast, genes in clusters 1, 3, and 6 (1752 DEGs), which were generally down-regulated at low temperature, encode antioxidant enzymes or are involved in glycerophospholipid, carbohydrate, or energy metabolism. We confirmed the results of the transcriptome analysis by quantitative RT-PCR. Our transcriptome analysis will advance our understanding of the comprehensive mechanisms of chilling injury during low temperature storage and facilitate improvements in postharvest storage of sweetpotato tuberous roots. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Biosynthesis of the neural cell adhesion molecule: characterization of polypeptide C

    DEFF Research Database (Denmark)

    Nybroe, O; Albrechtsen, M; Dahlin, J

    1985-01-01

    The biosynthesis of the neural cell adhesion molecule (N-CAM) was studied in primary cultures of rat cerebral glial cells, cerebellar granule neurons, and skeletal muscle cells. The three cell types produced different N-CAM polypeptide patterns. Glial cells synthesized a 135,000 Mr polypeptide B...... and a 115,000 Mr polypeptide C, whereas neurons expressed a 200,000 Mr polypeptide A as well as polypeptide B. Skeletal muscle cells produced polypeptide B. The polypeptides synthesized by the three cell types were immunochemically identical. The membrane association of polypeptide C was investigated...... with methods that distinguish peripheral and integral membrane proteins. Polypeptide C was found to be a peripheral membrane protein, whereas polypeptides A and B were integral membrane proteins with cytoplasmic domains of approximately 50,000 and approximately 25,000 Mr, respectively. The affinity...

  13. A transcriptional analysis of carotenoid, chlorophyll and plastidial isoprenoid biosynthesis genes during development and osmotic stress responses in Arabidopsis thaliana

    KAUST Repository

    Meier, Stuart

    2011-05-19

    Background: The carotenoids are pure isoprenoids that are essential components of the photosynthetic apparatus and are coordinately synthesized with chlorophylls in chloroplasts. However, little is known about the mechanisms that regulate carotenoid biosynthesis or the mechanisms that coordinate this synthesis with that of chlorophylls and other plastidial synthesized isoprenoid-derived compounds, including quinones, gibberellic acid and abscisic acid. Here, a comprehensive transcriptional analysis of individual carotenoid and isoprenoid-related biosynthesis pathway genes was performed in order to elucidate the role of transcriptional regulation in the coordinated synthesis of these compounds and to identify regulatory components that may mediate this process in Arabidopsis thaliana.Results: A global microarray expression correlation analysis revealed that the phytoene synthase gene, which encodes the first dedicated and rate-limiting enzyme of carotenogenesis, is highly co-expressed with many photosynthesis-related genes including many isoprenoid-related biosynthesis pathway genes. Chemical and mutant analysis revealed that induction of the co-expressed genes following germination was dependent on gibberellic acid and brassinosteroids (BR) but was inhibited by abscisic acid (ABA). Mutant analyses further revealed that expression of many of the genes is suppressed in dark grown plants by Phytochrome Interacting transcription Factors (PIFs) and activated by photoactivated phytochromes, which in turn degrade PIFs and mediate a coordinated induction of the genes. The promoters of PSY and the co-expressed genes were found to contain an enrichment in putative BR-auxin response elements and G-boxes, which bind PIFs, further supporting a role for BRs and PIFs in regulating expression of the genes. In osmotically stressed root tissue, transcription of Calvin cycle, methylerythritol 4-phosphate pathway and carotenoid biosynthesis genes is induced and uncoupled from that of

  14. Metagenomics at Grass Roots

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 22; Issue 3. Metagenomics at Grass Roots. Sudeshna ... benefit human health, agriculture, and ecosystemfunctions. This article provides a brief history of technicaladvances in metagenomics, including DNA sequencing methods,and some case studies.

  15. (Lamiaceae) root extracts

    African Journals Online (AJOL)

    Purpose: To evaluate the larvicidal, nematicidal, antifeedant, and antifungal effects of 10 solvent extracts of Mentha spicata root. Methods: Ten solvent extracts were investigated for their total flavonoid and phenolic content and screened for larvicidal, nematicidal, antifeedant, and antifungal activities. The total phenolic ...

  16. Root-knot nematodes induce pattern-triggered immunity in Arabidopsis thaliana roots.

    Science.gov (United States)

    Teixeira, Marcella A; Wei, Lihui; Kaloshian, Isgouhi

    2016-07-01

    Root-knot nematodes (RKNs; Meloidogyne spp.) are plant parasites with a broad host range causing great losses worldwide. To parasitize their hosts, RKNs establish feeding sites in roots known as giant cells. The majority of work studying plant-RKN interactions in susceptible hosts addresses establishment of the giant cells and there is limited information on the early defense responses. Here we characterized early defense or pattern-triggered immunity (PTI) against RKNs in Arabidopsis thaliana. To address PTI, we evaluated known canonical PTI signaling mutants with RKNs and investigated the expression of PTI marker genes after RKN infection using both quantitative PCR and β-glucuronidase reporter transgenic lines. We showed that PTI-compromised plants have enhanced susceptibility to RKNs, including the bak1-5 mutant. BAK1 is a common partner of distinct receptors of microbe- and damage-associated molecular patterns. Furthermore, our data indicated that nematode recognition leading to PTI responses involves camalexin and glucosinolate biosynthesis. While the RKN-induced glucosinolate biosynthetic pathway was BAK1-dependent, the camalexin biosynthetic pathway was only partially dependent on BAK1. Combined, our results indicate the presence of BAK1-dependent and -independent PTI against RKNs in A. thaliana, suggesting the existence of diverse nematode recognition mechanisms. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  17. Cysteine Biosynthesis Controls Serratia marcescens Phospholipase Activity.

    Science.gov (United States)

    Anderson, Mark T; Mitchell, Lindsay A; Mobley, Harry L T

    2017-08-15

    Serratia marcescens causes health care-associated opportunistic infections that can be difficult to treat due to a high incidence of antibiotic resistance. One of the many secreted proteins of S. marcescens is the PhlA phospholipase enzyme. Genes involved in the production and secretion of PhlA were identified by screening a transposon insertion library for phospholipase-deficient mutants on phosphatidylcholine-containing medium. Mutations were identified in four genes ( cyaA , crp , fliJ , and fliP ) that are involved in the flagellum-dependent PhlA secretion pathway. An additional phospholipase-deficient isolate harbored a transposon insertion in the cysE gene encoding a predicted serine O -acetyltransferase required for cysteine biosynthesis. The cysE requirement for extracellular phospholipase activity was confirmed using a fluorogenic phospholipase substrate. Phospholipase activity was restored to the cysE mutant by the addition of exogenous l-cysteine or O -acetylserine to the culture medium and by genetic complementation. Additionally, phlA transcript levels were decreased 6-fold in bacteria lacking cysE and were restored with added cysteine, indicating a role for cysteine-dependent transcriptional regulation of S. marcescens phospholipase activity. S. marcescens cysE mutants also exhibited a defect in swarming motility that was correlated with reduced levels of flhD and fliA flagellar regulator gene transcription. Together, these findings suggest a model in which cysteine is required for the regulation of both extracellular phospholipase activity and surface motility in S. marcescens IMPORTANCE Serratia marcescens is known to secrete multiple extracellular enzymes, but PhlA is unusual in that this protein is thought to be exported by the flagellar transport apparatus. In this study, we demonstrate that both extracellular phospholipase activity and flagellar function are dependent on the cysteine biosynthesis pathway. Furthermore, a disruption of cysteine

  18. A comparative modeling and molecular docking study on Mycobacterium tuberculosis targets involved in peptidoglycan biosynthesis.

    Science.gov (United States)

    Fakhar, Zeynab; Naiker, Suhashni; Alves, Claudio N; Govender, Thavendran; Maguire, Glenn E M; Lameira, Jeronimo; Lamichhane, Gyanu; Kruger, Hendrik G; Honarparvar, Bahareh

    2016-11-01

    An alarming rise of multidrug-resistant Mycobacterium tuberculosis strains and the continuous high global morbidity of tuberculosis have reinvigorated the need to identify novel targets to combat the disease. The enzymes that catalyze the biosynthesis of peptidoglycan in M. tuberculosis are essential and noteworthy therapeutic targets. In this study, the biochemical function and homology modeling of MurI, MurG, MraY, DapE, DapA, Alr, and Ddl enzymes of the CDC1551 M. tuberculosis strain involved in the biosynthesis of peptidoglycan cell wall are reported. Generation of the 3D structures was achieved with Modeller 9.13. To assess the structural quality of the obtained homology modeled targets, the models were validated using PROCHECK, PDBsum, QMEAN, and ERRAT scores. Molecular dynamics simulations were performed to calculate root mean square deviation (RMSD) and radius of gyration (Rg) of MurI and MurG target proteins and their corresponding templates. For further model validation, RMSD and Rg for selected targets/templates were investigated to compare the close proximity of their dynamic behavior in terms of protein stability and average distances. To identify the potential binding mode required for molecular docking, binding site information of all modeled targets was obtained using two prediction algorithms. A docking study was performed for MurI to determine the potential mode of interaction between the inhibitor and the active site residues. This study presents the first accounts of the 3D structural information for the selected M. tuberculosis targets involved in peptidoglycan biosynthesis.

  19. Genes associated with 2-methylisoborneol biosynthesis in cyanobacteria: isolation, characterization, and expression in response to light.

    Directory of Open Access Journals (Sweden)

    Zhongjie Wang

    Full Text Available The volatile microbial metabolite 2-methylisoborneol (2-MIB is a root cause of taste and odor issues in freshwater. Although current evidence suggests that 2-MIB is not toxic, this compound degrades water quality and presents problems for water treatment. To address these issues, cyanobacteria and actinomycetes, the major producers of 2-MIB, have been investigated extensively. In this study, two 2-MIB producing strains, coded as Pseudanabaena sp. and Planktothricoids raciborskii, were used in order to elucidate the genetic background, light regulation, and biochemical mechanisms of 2-MIB biosynthesis in cyanobacteria. Genome walking and PCR methods revealed that two adjacent genes, SAM-dependent methyltransferanse gene and monoterpene cyclase gene, are responsible for GPP methylation and subsequent cyclization to 2-MIB in cyanobacteria. These two genes are located in between two homologous cyclic nucleotide-binding protein genes that may be members of the Crp-Fnr regulator family. Together, this sequence of genes forms a putative operon. The synthesis of 2-MIB is similar in cyanobacteria and actinomycetes. Comparison of the gene arrangement and functional sites between cyanobacteria and other organisms revealed that gene recombination and gene transfer probably occurred during the evolution of 2-MIB-associated genes. All the microorganisms examined have a common origin of 2-MIB biosynthesis capacity, but cyanobacteria represent a unique evolutionary lineage. Gene expression analysis suggested that light is a crucial, but not the only, active regulatory factor for the transcription of 2-MIB synthesis genes. This light-regulated process is immediate and transient. This study is the first to identify the genetic background and evolution of 2-MIB biosynthesis in cyanobacteria, thus enhancing current knowledge on 2-MIB contamination of freshwater.

  20. Comparative Transcriptomic Analysis of Grape Berry in Response to Root Restriction during Developmental Stages

    Directory of Open Access Journals (Sweden)

    Feng Leng

    2016-10-01

    Full Text Available Root restriction improved berry quality by being involved in diverse aspects of grapevine life. However, the molecular mechanism driving this process is not understood very well. In this study, the ‘Summer Black’ grape berry (Vitis vinifera × V. labrusca under root restriction was investigated, which showed an increase of total soluble solids (TSS, color index of red grapes (CIRG value, anthocyanins accumulation, total phenolics and total procyanidins contents during berry development compared with those in control berries. The transcriptomic changes induced by root restriction in ‘Summer Black’ grape over the course of berry development were analyzed by RNA-Seq method. A total of 29,971 genes were generated in ‘Summer Black’ grape berry during development, among which, 1606 genes were significantly responded to root restriction. Furthermore, 1264, 313, 141, 246 and 19 sequences were significantly changed at S1, S2, S3, S4 and S5 sample points, respectively. The gene (VIT_04s0023g02290 predicted as a salicylate O-methyltransferase was differentially expressed in all developmental stages. Gene Ontology (GO enrichment showed that response to organic nitrogen, response to endogenous stimulus, flavonoid metabolic process, phenylpropanoid biosynthetic process and cell wall macromolecule metabolic process were the main significant differential categories. Kyoto Encyclopedia of Genes and Genomes (KEGG pathway enrichment revealed plant–pathogen interaction, plant hormone signal transduction, flavone and flavonol biosynthesis, flavonoid biosynthesis and glucosinolate biosynthesis were the main significant differential pathways. The results of the present study provided a genetic base for the understanding of grape berry fruit quality improvement under root restriction.

  1. Distinguishing between Dirac and Majorana neutrinos withtwo-particle interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Thomas D.

    2006-03-02

    Two-particle interferometry, a second-order interferenceeffect, is explored as another possible tool to distinguish betweenmassive Dirac and Majorana neutrinos. A simple theoretical framework isdiscussed in the context of several gedanken experiments. The method canin principle provide both the mass scale and the quantum nature of theneutrino for a certain class of incoherent left-handed sourcecurrents.

  2. 29 CFR 794.107 - “Establishment” distinguished.

    Science.gov (United States)

    2010-07-01

    ... the definition of “enterprise” in section 3(r), as set forth in § 794.106, that the activities of the... § 794.107 “Establishment” distinguished. The “enterprise” referred to in the section 7(b)(3) exemption... “an entire business or enterprise” which may include several separate places of business. (See...

  3. Distinguishing between Exogenous and Endogenous Intent-to-Transfer Students

    Science.gov (United States)

    Okun, Morris A.; Karoly, Paul; Martin, Jessica L.; Benshoff, Annja

    2009-01-01

    In this article, we distinguish between 2 types of students who intend to transfer and graduate from another institution. During the fall of 2006, 507 first-semester students attending a state university completed a survey. Seventy-six percent of the students indicated that they planned on graduating from the University (intent-to-persist), 16%…

  4. Investigation of soil salinity to distinguish boundary line between ...

    African Journals Online (AJOL)

    Gradual drying of Urmia Lake has left vast saline areas all around it, increasing the risk of salinization of agricultural lands next to the Lake. The current research was aimed to predict soil salinity and distinguish the boundary line between saline and agricultural lands by taking in to account the spatial variability of soil salinity ...

  5. Distinguishing method for contamination/radio-activation of radioactive wastes

    International Nuclear Information System (INIS)

    Fukazawa, Takuji; Kato, Keiichiro; Koda, Satoshi.

    1994-01-01

    The present invention concerns a method of distinguishing the contamination/radio-activation of radioactive wastes used in processing wastes generated upon dismantling of exhausted nuclear reactors. Especially, contaminated/radio-activation is distinguished for wastes having openings such as pipes and valves, by utilizing scattering of γ-rays or γ-ray to β-ray ratio. That is, ratio of scattered γ-rays and direct γ-rays or ratio of β-rays and γ-rays from radioactive wastes are measured and compared by a radiation detector, to distinguish whether the radioactive wastes contaminated materials or radio-activated materials. For example, when an object to be measured having an opening is contaminated at the inner side, the radiation detector facing to the opening mainly detects high direct γ-rays emitted from the object to be measured while a radiation detector not facing the opening mainly detects high scattered γ-rays relatively. On the other hand, when the object is a radio-activated material, any of the detectors detect scattered γ-rays, so that they can be distinguished by these ratios. (I.S.)

  6. Distinguishing between Realistic and Fantastical Figures in Iran

    Science.gov (United States)

    Davoodi, Telli; Corriveau, Kathleen H.; Harris, Paul L.

    2016-01-01

    Children in the United States come to distinguish historical from fictional story figures between the ages of 3 and 5 years, guided by the plausibility of the story events surrounding the figure (Corriveau, Kim, Schwalen, & Harris, 2009; Woolley & Cox, 2007). However, U.S. children vary in their reactions to stories that include…

  7. Metabolic markers as possible diagnostic tools to distinguish ...

    African Journals Online (AJOL)

    No metabolic markers could distinguish between gram positive and gram negative septicemia. α-Amino-adipic acid, citramalic acid and xanthurenic acid, produced only by bacteria, show promise. Alanine and glycine increased significantly over 24 h and can be used as diagnostic markers and perhaps as markers of ...

  8. Studies to distinguish between human and animal faecal pollution ...

    African Journals Online (AJOL)

    A variety of techniques have been described to distinguish between human and animal faecal pollution of water. F-RNA (male-specific) coliphages have been classified into four sero-groups and evidence has been presented that two of these sero-groups are specific for human excreta and the other two for animal excreta.

  9. Cancer Prevention: Distinguishing Strength of Evidence from Strength of Opinion

    Science.gov (United States)

    Barnett S. Kramer, MD, MPH, Associate Director for Disease Prevention and Director of the Office of Medical Applications of Research in the Office of Disease Prevention, Office of the Director, National Institutes of Health, Bethesda, MD, presented "Cancer Prevention: Distinguishing Strength of Evidence from Strength of Opinion".

  10. DMBT1 expression distinguishes anorectal from cutaneous melanoma

    DEFF Research Database (Denmark)

    Helmke, Burkhard Maria; Renner, Marcus; Poustka, Annemarie

    2009-01-01

    or with melanocytic naevi. While AMs are clearly distinguished from CM by displaying few BRAF mutations, they are commonly indistinguishable from CM at the level of gene expression. The aim was to carry out expression analyses of classical immunohistochemical markers and of the protein deleted in malignant brain...

  11. Ability to distinguish whisky (uisge beatha) from brandy (cognac).

    Science.gov (United States)

    Campbell, E J; Campbell, D M; Roberts, R S

    To assess ability to distinguish between first rate malt whisky and brandy and between different brands of each. Crossover with two sessions of 12 blindfold tastings of two whiskies and two brandies before and after supper, repeated not more than seven days later. Dundas, Ontario. 4 volunteers aged 50-68 years, all moderate drinkers of alcohol and members of a wine club. Proportion of samples correctly identified (whisky v brandy) and, of those, the proportion of brands correctly identified. Only one participant produced irrefutable statistical evidence (P < 0.0001) of being able to distinguish between whisky and brandy, correctly identifying 50/51 (98%) samples. Two participants achieved some success in identification (72%, P = 0.0031 and 65% P = 0.031). The fourth participant's responses reflected pure guesswork. Brandy was no easier to identify than whisky (P = 0.84). The participant who was best able to distinguish between whisky and brandy was also best able to identify correctly the brand of whisky (100%, P < 0.0001). Despite the fact that not all participants completed the full number of tastings the results show that some participants could distinguish neither between malt whisky and brandy nor between different brands of whisky and brandy. However, the success of one participant shows that "it can be done" and that his whisky specific ability is acquired not innate.

  12. Kelly D. Brownell: Award for Distinguished Scientific Applications of Psychology

    Science.gov (United States)

    American Psychologist, 2012

    2012-01-01

    Presents a short biography of Kelly D. Brownwell, winner of the American Psychological Association's Award for Distinguished Scientific Applications of Psychology (2012). He won the award for outstanding contributions to our understanding of the etiology and management of obesity and the crisis it poses for the modern world. A seminal thinker in…

  13. Metabolic markers as possible diagnostic tools to distinguish ...

    African Journals Online (AJOL)

    Jane

    2010-12-20

    Dec 20, 2010 ... In conclusion, (in PDF file it is conclusively) metabolites can be used to diagnose septicemia and possibly its progression, but not to distinguish between gram positive and gram negative septicemia. Key words: Septicaemia, baboon, Gram negative, Gram positive, metabolic marker. INTRODUCTION.

  14. Studies to distinguish between human and animal faecal pollution ...

    African Journals Online (AJOL)

    Human enteric viral infections are considered to be predominantly associated with human wastes, as opposed to animal wastes, and a distinction between these has benefits for water quality control and risk assessment. A variety of techniques have been described to distinguish between human and animal faecal pollution ...

  15. Plasma sarcosine does not distinguish early and advanced stages ...

    African Journals Online (AJOL)

    Introduction. Diagnosis of prostate cancer by prostate specific antigen (PSA) is error-prone and cannot distinguish benign prostatic hyperplasia (BPH) from malignant disease, nor identify aggressive and indolent types. Methods. We determined serum sarcosine (N-methylglycine) in 328 cancer patients by gas ...

  16. Daniel L. Schacter: Award for Distinguished Scientific Contributions

    Science.gov (United States)

    American Psychologist, 2012

    2012-01-01

    Presents Daniel L. Schacter as one of the winners of the American Psychological Association's Award for Distinguished Scientific Contributions (2012). Daniel L. Schacter's major theoretical and empirical contributions include groundbreaking research on the psychological and neural foundations of implicit and explicit memory, memory distortions and…

  17. Compound specific stable isotopes as probes for distinguishing the sources of biomolecules in terrestrial and extraterrestrial materials

    Science.gov (United States)

    Engel, M. H.; Macko, S. A.

    2003-04-01

    Life on Earth consists of orderly arrangements of several key types of organic compounds (amino acids, sugars, fatty acids, nucleic bases) that are the building blocks of proteins, carbohydrates, lipids and nucleotides. Subsequent to death, macromolecules are commonly broken down to their molecular constituents or other similar scale components. Thus, in ancient terrestrial and extraterrestrial materials, it is far more likely to expect the presence of simple compounds such as amino acids rather than the proteins from which they were possibly derived. Given that amino acids, for example, are common components of all extinct and extant organisms, the challenge has been to develop methods for distinguishing their sources. Stable isotopes are powerful probes for determining the origins of organic matter. Amino acid constituents of all organisms on Earth exhibit characteristic stable isotope compositions owing to fractionations associated with their biosynthesis. These fractionations are distinct from those observed for amino acids formed by abiotic processes. Thus it should be possible to use isotopes as probes for determining whether amino acids in ancient rocks on Earth are biotic or abiotic, based on their relative isotopic compositions. Also, owing to differences in the isotope compositions of precursors, amino acids in extraterrestrial materials such as carbonaceous meteorites are moderately to substantially enriched in the heavy isotopes of C, N and H relative to terrestrial amino acids. Assuming that the isotope compositions of the gaseous components of, for example, the Martian atmosphere were distinct from Earth at such time when organic molecules may have formed, it should be possible to distinguish these components from terrestrial contaminants by determining their isotope compositions and/or those of their respective enantiomers. Also, if life as we know it existed on another planet such as Mars, fractionations characteristic of biosynthesis should be

  18. Three Principles of Diversity-Generating Biosynthesis.

    Science.gov (United States)

    Gu, Wenjia; Schmidt, Eric W

    2017-10-17

    Natural products are significant therapeutic agents and valuable drug leads. This is likely owing to their three-dimensional structural complexity, which enables them to form complex interactions with biological targets. Enzymes from natural product biosynthetic pathways show great potential to generate natural product-like compounds and libraries. Many challenges still remain in biosynthesis, such as how to rationally synthesize small molecules with novel structures and how to generate maximum chemical diversity. In this Account, we describe recent advances from our laboratory in the synthesis of natural product-like libraries using natural biosynthetic machinery. Our work has focused on the pat and tru biosynthetic pathways to patellamides, trunkamide, and related compounds from cyanobacterial symbionts in marine tunicates. These belong to the cyanobactin class of natural products, which are part of the larger group of ribosomally synthesized and post-translationally modified peptides (RiPPs). These results have enabled the synthesis of rationally designed small molecules and libraries covering more than 1 million estimated derivatives. Because the RiPPs are translated on the ribosome and then enzymatically modified, they are highly compatible with recombinant technologies. This is important because it means that the resulting natural products, their derivatives, and wholly new compounds can be synthesized using the tools of genetic engineering. The RiPPs also represent possibly the most widespread group of bioactive natural products, although this is in part because of the broad definition of what constitutes a RiPP. In addition, the underlying ideas may form the basis for broad-substrate biosynthetic pathways beyond the RiPPs. For example, some of the ideas about kinetic ordering of broad substrate pathways may apply to polyketide or nonribosomal peptide biosynthesis as well. While making these products, we have sought to understand what makes biosynthetic

  19. Polyamine biosynthesis during germination of yeast ascospores.

    Science.gov (United States)

    Brawley, J V; Ferro, A J

    1979-01-01

    The role of the diamine putrescine during germination and outgrowth of ascospores of Saccharomyces cerevisiae was examined. Ornithine decarboxylase activity increased and declined rapidly during germination and outgrowth; peak activity was attained after the cells had proceeded through the G1 interval of the cell cycle, whereas minimal activity was present at the completion of the first cell division. alpha-Methylornithine inhibited both ornithine decarboxylase activity and the in vivo accumulation of putrescine. In the presence of alpha-methylornithireak dormancy and proceed through one cell division. Subsequent cellular growth, however, was retarded but not completely inhibited. The supplementation of Methylglyoxal bis(guanylhydrazone) to sporulation medium greatly inhibited this sexual process. These data suggest that the synthesis of putrescine is not required for the breaking of spore dormancy, but that polyamine biosynthesis may be essential for meiosis and sporulation. PMID:387744

  20. Biosynthesis and function of plant lipids

    International Nuclear Information System (INIS)

    Thomson, W.W.; Mudd, J.B.; Gibbs, M.

    1983-01-01

    The Sixth Annual Symposium in Botany and Plant Physiology was held January 13-15, 1983, at the University of California, Riverside. This volume comprises the papers that were presented. Subjects discussed at the symposium covered a wide range in the field of plant lipids. Biosynthesis of lipids occupied an important fraction of the presentations at the symposium. Subjects included detailed studies of the enzymes of fatty acid synthesis, several discussions of the incorporation of fatty acids into glycerolipids and the further modification of the fatty acids, and the synthesis of glycerolipids and desaturation of fatty acids in both maturing oilseeds and chloroplasts. The physicochemical studies of glycerolipids and sterols in artificial membranes have led to distinct conclusions about their behaviour which must be relevant in the biological membrane. Results on the functional consequences of modifying the galactolipid composition in the chloroplast were an encouraging sign of progress in the attempts to relate membrane lipid composition to physiological function

  1. Biosurfactant Mediated Biosynthesis of Selected Metallic Nanoparticles

    Science.gov (United States)

    Płaza, Grażyna A.; Chojniak, Joanna; Banat, Ibrahim M.

    2014-01-01

    Developing a reliable experimental protocol for the synthesis of nanomaterials is one of the challenging topics in current nanotechnology particularly in the context of the recent drive to promote green technologies in their synthesis. The increasing need to develop clean, nontoxic and environmentally safe production processes for nanoparticles to reduce environmental impact, minimize waste and increase energy efficiency has become essential in this field. Consequently, recent studies on the use of microorganisms in the synthesis of selected nanoparticles are gaining increased interest as they represent an exciting area of research with considerable development potential. Microorganisms are known to be capable of synthesizing inorganic molecules that are deposited either intra- or extracellularly. This review presents a brief overview of current research on the use of biosurfactants in the biosynthesis of selected metallic nanoparticles and their potential importance. PMID:25110864

  2. Terpenoids and Their Biosynthesis in Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Bagmi Pattanaik

    2015-01-01

    Full Text Available Terpenoids, or isoprenoids, are a family of compounds with great structural diversity which are essential for all living organisms. In cyanobacteria, they are synthesized from the methylerythritol-phosphate (MEP pathway, using glyceraldehyde 3-phosphate and pyruvate produced by photosynthesis as substrates. The products of the MEP pathway are the isomeric five-carbon compounds isopentenyl diphosphate and dimethylallyl diphosphate, which in turn form the basic building blocks for formation of all terpenoids. Many terpenoid compounds have useful properties and are of interest in the fields of pharmaceuticals and nutrition, and even potentially as future biofuels. The MEP pathway, its function and regulation, and the subsequent formation of terpenoids have not been fully elucidated in cyanobacteria, despite its relevance for biotechnological applications. In this review, we summarize the present knowledge about cyanobacterial terpenoid biosynthesis, both regarding the native metabolism and regarding metabolic engineering of cyanobacteria for heterologous production of non-native terpenoids.

  3. Terpenoids and Their Biosynthesis in Cyanobacteria

    Science.gov (United States)

    Pattanaik, Bagmi; Lindberg, Pia

    2015-01-01

    Terpenoids, or isoprenoids, are a family of compounds with great structural diversity which are essential for all living organisms. In cyanobacteria, they are synthesized from the methylerythritol-phosphate (MEP) pathway, using glyceraldehyde 3-phosphate and pyruvate produced by photosynthesis as substrates. The products of the MEP pathway are the isomeric five-carbon compounds isopentenyl diphosphate and dimethylallyl diphosphate, which in turn form the basic building blocks for formation of all terpenoids. Many terpenoid compounds have useful properties and are of interest in the fields of pharmaceuticals and nutrition, and even potentially as future biofuels. The MEP pathway, its function and regulation, and the subsequent formation of terpenoids have not been fully elucidated in cyanobacteria, despite its relevance for biotechnological applications. In this review, we summarize the present knowledge about cyanobacterial terpenoid biosynthesis, both regarding the native metabolism and regarding metabolic engineering of cyanobacteria for heterologous production of non-native terpenoids. PMID:25615610

  4. A Molecular Description of Cellulose Biosynthesis

    Science.gov (United States)

    McNamara, Joshua T.; Morgan, Jacob L.W.; Zimmer, Jochen

    2016-01-01

    Cellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Despite the biological and societal importance of cellulose, the molecular mechanism by which it is synthesized is now only beginning to emerge. On the basis of recent advances in structural and molecular biology on bacterial cellulose synthases, we review emerging concepts of how the enzymes polymerize glucose molecules, how the nascent polymer is transported across the plasma membrane, and how bacterial cellulose biosynthesis is regulated during biofilm formation. Additionally, we review evolutionary commonalities and differences between cellulose synthases that modulate the nature of the cellulose product formed. PMID:26034894

  5. Biosurfactant Mediated Biosynthesis of Selected Metallic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Grażyna A. Płaza

    2014-08-01

    Full Text Available Developing a reliable experimental protocol for the synthesis of nanomaterials is one of the challenging topics in current nanotechnology particularly in the context of the recent drive to promote green technologies in their synthesis. The increasing need to develop clean, nontoxic and environmentally safe production processes for nanoparticles to reduce environmental impact, minimize waste and increase energy efficiency has become essential in this field. Consequently, recent studies on the use of microorganisms in the synthesis of selected nanoparticles are gaining increased interest as they represent an exciting area of research with considerable development potential. Microorganisms are known to be capable of synthesizing inorganic molecules that are deposited either intra- or extracellularly. This review presents a brief overview of current research on the use of biosurfactants in the biosynthesis of selected metallic nanoparticles and their potential importance.

  6. Introduction to the ROOT System

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    Introduction to the ROOT data handling system. ROOT is used in some for or another by all LHC experiments and will be used by all for final data analysis. The introduction gives an overview of the system. Prerequisite knowledge: C++

  7. Variation in root wood anatomy

    NARCIS (Netherlands)

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  8. [Opine biosynthesis and catabolism genes of Agrobacterium tumefaciens and Agrobacterium rhizogenes].

    Science.gov (United States)

    Vladimirov, I A; Matveeva, T V; Lutova, L A

    2015-02-01

    Agrobacterium is a genus of soil bacteria with the ability to transform plant cells by a T-DNA-sequence located on the pTi/pRi- plasmid containing a set of genes expressed in plant cells. Expression of these genes leads to a proliferation of transformed cells, with the subsequent formation of tumors or growths of roots and the synthesis of opines--products of the condensation of amino acids with ketoacids or sugars used by Agrobacteria as a source of carbon and nitrogen. In this review, we systematized the information about most common opines in plant--Agrobacterium systems and their biosynthesis and catabolism genes, as well as the role of opines in the interaction of pathogenic Agrobacterium with plants and with other Agrobacterium strains, including the genetic consequences of such interactions.

  9. Engineering Plant Architecture via CRISPR/Cas9-mediated Alteration of Strigolactone Biosynthesis

    KAUST Repository

    Butt, Haroon

    2018-01-28

    Precision plant genome engineering holds much promise for targeted improvement of crop traits via unprecedented single-base level control over the genetic material. Strigolactones (SLs) are a key determinant of plant architecture, known for their role in inhibiting shoot branching (tillering). Here, we used CRISPR/Cas9 in rice (Oryza sativa) for targeted disruption of CAROTENOID CLEAVAGE DIOXYGENASE 7 (CCD7), which controls a key step in SL biosynthesis. The ccd7 mutants exhibited a striking increase in tillering, combined with a dwarf phenotype, which could be rescued by application of the synthetic SL analog GR24. Striga germination assays and liquid chromatography mass spectrometry analysis showed that root exudates of ccd7 mutants were also SL deficient. Taken together, our results show the power of CRISPR/Cas9 for targeted engineering of plant architecture and for elucidating the molecular underpinnings of architecture-related traits.

  10. Acylphloroglucinol Biosynthesis in Strawberry Fruit1

    Science.gov (United States)

    Song, Chuankui; Ring, Ludwig; Hoffmann, Thomas; Huang, Fong-Chin; Slovin, Janet; Schwab, Wilfried

    2015-01-01

    Phenolics have health-promoting properties and are a major group of metabolites in fruit crops. Through reverse genetic analysis of the functions of four ripening-related genes in the octoploid strawberry (Fragaria × ananassa), we discovered four acylphloroglucinol (APG)-glucosides as native Fragaria spp. fruit metabolites whose levels were differently regulated in the transgenic fruits. The biosynthesis of the APG aglycones was investigated by examination of the enzymatic properties of three recombinant Fragaria vesca chalcone synthase (FvCHS) proteins. CHS is involved in anthocyanin biosynthesis during ripening. The F. vesca enzymes readily catalyzed the condensation of two intermediates in branched-chain amino acid metabolism, isovaleryl-Coenzyme A (CoA) and isobutyryl-CoA, with three molecules of malonyl-CoA to form phlorisovalerophenone and phlorisobutyrophenone, respectively, and formed naringenin chalcone when 4-coumaroyl-CoA was used as starter molecule. Isovaleryl-CoA was the preferred starter substrate of FvCHS2-1. Suppression of CHS activity in both transient and stable CHS-silenced fruit resulted in a substantial decrease of APG glucosides and anthocyanins and enhanced levels of volatiles derived from branched-chain amino acids. The proposed APG pathway was confirmed by feeding isotopically labeled amino acids. Thus, Fragaria spp. plants have the capacity to synthesize pharmaceutically important APGs using dual functional CHS/(phloriso)valerophenone synthases that are expressed during fruit ripening. Duplication and adaptive evolution of CHS is the most probable scenario and might be generally applicable to other plants. The results highlight that important promiscuous gene function may be missed when annotation relies solely on in silico analysis. PMID:26169681

  11. Concerted transcription of auxin and carbohydrate homeostasis-related genes underlies improved adventitious rooting of microcuttings derived from far-red treated Eucalyptus globulus Labill mother plants.

    Science.gov (United States)

    Ruedell, Carolina Michels; de Almeida, Márcia Rodrigues; Fett-Neto, Arthur Germano

    2015-12-01

    Economically important plant species, such as Eucalyptus globulus, are often rooting recalcitrant. We have previously shown that far-red light enrichment applied to E. globulus donor-plants improved microcutting rooting competence and increased rooting zone/shoot carbohydrate ratio. To better understand this developmental response, the relative expression profiles of genes involved in auxin signaling (ARF6, ARF8, AGO1), biosynthesis (YUC3) and transport (AUX1, PIN1, PIN2); sucrose cleavage (SUS1, CWINV1), transport (SUC5), hexose phosphorylation (HXK1, FLN1) and starch biosynthesis (SS3) were quantified during adventitious rooting of E. globulus microcuttings derived from donor plants exposed to far-red or white light. Expression of auxin transport-related genes increased in the first days of root induction. Far-red enrichment of donor plants induced ARF6, ARF8 and AGO1 in microcuttings. The first two gene products could activate GH3 and other rooting related genes, whereas AGO1 deregulation of the repressor ARF17 may relief rooting inhibition. Increased sink strength at the basal stem with sucrose unloading in root tissue mediated by SUC and subsequent hydrolysis by SUS1 were also supported by gene expression profile. Fructose phosphorylation and starch biosynthesis could also contribute to proper carbon allocation at the site of rooting, as evidenced by increased expression of related genes. These data are in good agreement with increased contents of hexoses and starch at the cutting base severed from far-red exposed donor plants. To sum up, pathways integrating auxin and carbohydrate metabolism were activated in microcuttings derived from donor plants exposed to far red light enrichment, thereby improving rooting response in E. globulus. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Ethylene responses in rice roots and coleoptiles are differentially regulated by a carotenoid isomerase-mediated abscisic acid pathway.

    Science.gov (United States)

    Yin, Cui-Cui; Ma, Biao; Collinge, Derek Phillip; Pogson, Barry James; He, Si-Jie; Xiong, Qing; Duan, Kai-Xuan; Chen, Hui; Yang, Chao; Lu, Xiang; Wang, Yi-Qin; Zhang, Wan-Ke; Chu, Cheng-Cai; Sun, Xiao-Hong; Fang, Shuang; Chu, Jin-Fang; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2015-04-01

    Ethylene and abscisic acid (ABA) act synergistically or antagonistically to regulate plant growth and development. ABA is derived from the carotenoid biosynthesis pathway. Here, we analyzed the interplay among ethylene, carotenoid biogenesis, and ABA in rice (Oryza sativa) using the rice ethylene response mutant mhz5, which displays a reduced ethylene response in roots but an enhanced ethylene response in coleoptiles. We found that MHZ5 encodes a carotenoid isomerase and that the mutation in mhz5 blocks carotenoid biosynthesis, reduces ABA accumulation, and promotes ethylene production in etiolated seedlings. ABA can largely rescue the ethylene response of the mhz5 mutant. Ethylene induces MHZ5 expression, the production of neoxanthin, an ABA biosynthesis precursor, and ABA accumulation in roots. MHZ5 overexpression results in enhanced ethylene sensitivity in roots and reduced ethylene sensitivity in coleoptiles. Mutation or overexpression of MHZ5 also alters the expression of ethylene-responsive genes. Genetic studies revealed that the MHZ5-mediated ABA pathway acts downstream of ethylene signaling to inhibit root growth. The MHZ5-mediated ABA pathway likely acts upstream but negatively regulates ethylene signaling to control coleoptile growth. Our study reveals novel interactions among ethylene, carotenogenesis, and ABA and provides insight into improvements in agronomic traits and adaptive growth through the manipulation of these pathways in rice. © 2015 American Society of Plant Biologists. All rights reserved.

  13. Springback in root gravitropism

    Science.gov (United States)

    Leopold, A. C.; Wettlaufer, S. H.

    1989-01-01

    Conditions under which a gravistimulus of Merit corn roots (Zea mays L.) is withdrawn result in a subsequent loss of gravitropic curvature, an effect which we refer to as springback.' This loss of curvature begins within 1 to 10 minutes after removal of the gravistimulus. It occurs regardless of the presence or absence of the root cap. It is insensitive to inhibitors of auxin transport (2,3,5-triiodobenzoic acid, naphthylphthalamic [correction of naphthylphthalmaic] acid) or to added auxin (2,4-dichlorophenoxyacetic acid). Springback is prevented if a clinostat treatment is interjected to neutralize gravistimulation during germination, which suggests that the change in curvature is a response to a memory' effect carried over from a prior gravistimulation.

  14. Aquaporins and root water uptake

    Science.gov (United States)

    Water is one of the most critical resources limiting plant growth and crop productivity, and root water uptake is an important aspect of plant physiology governing plant water use and stress tolerance. Pathways of root water uptake are complex and are affected by root structure and physiological res...

  15. Expressing Parallelism with ROOT

    Science.gov (United States)

    Piparo, D.; Tejedor, E.; Guiraud, E.; Ganis, G.; Mato, P.; Moneta, L.; Valls Pla, X.; Canal, P.

    2017-10-01

    The need for processing the ever-increasing amount of data generated by the LHC experiments in a more efficient way has motivated ROOT to further develop its support for parallelism. Such support is being tackled both for shared-memory and distributed-memory environments. The incarnations of the aforementioned parallelism are multi-threading, multi-processing and cluster-wide executions. In the area of multi-threading, we discuss the new implicit parallelism and related interfaces, as well as the new building blocks to safely operate with ROOT objects in a multi-threaded environment. Regarding multi-processing, we review the new MultiProc framework, comparing it with similar tools (e.g. multiprocessing module in Python). Finally, as an alternative to PROOF for cluster-wide executions, we introduce the efforts on integrating ROOT with state-of-the-art distributed data processing technologies like Spark, both in terms of programming model and runtime design (with EOS as one of the main components). For all the levels of parallelism, we discuss, based on real-life examples and measurements, how our proposals can increase the productivity of scientists.

  16. Expressing Parallelism with ROOT

    Energy Technology Data Exchange (ETDEWEB)

    Piparo, D. [CERN; Tejedor, E. [CERN; Guiraud, E. [CERN; Ganis, G. [CERN; Mato, P. [CERN; Moneta, L. [CERN; Valls Pla, X. [CERN; Canal, P. [Fermilab

    2017-11-22

    The need for processing the ever-increasing amount of data generated by the LHC experiments in a more efficient way has motivated ROOT to further develop its support for parallelism. Such support is being tackled both for shared-memory and distributed-memory environments. The incarnations of the aforementioned parallelism are multi-threading, multi-processing and cluster-wide executions. In the area of multi-threading, we discuss the new implicit parallelism and related interfaces, as well as the new building blocks to safely operate with ROOT objects in a multi-threaded environment. Regarding multi-processing, we review the new MultiProc framework, comparing it with similar tools (e.g. multiprocessing module in Python). Finally, as an alternative to PROOF for cluster-wide executions, we introduce the efforts on integrating ROOT with state-of-the-art distributed data processing technologies like Spark, both in terms of programming model and runtime design (with EOS as one of the main components). For all the levels of parallelism, we discuss, based on real-life examples and measurements, how our proposals can increase the productivity of scientists.

  17. Deep sequencing of Lotus corniculatus L. reveals key enzymes and potential transcription factors related to the flavonoid biosynthesis pathway.

    Science.gov (United States)

    Wang, Ying; Hua, Wenping; Wang, Jian; Hannoufa, Abdelali; Xu, Ziqin; Wang, Zhezhi

    2013-04-01

    Lotus corniculatus L. is used worldwide as a forage crop due to its abundance of secondary metabolites and its ability to grow in severe environments. Although the entire genome of L. corniculatus var. japonicus R. is being sequenced, the differences in morphology and production of secondary metabolites between these two related species have led us to investigate this variability at the genetic level, in particular the differences in flavonoid biosynthesis. Our goal is to use the resulting information to develop more valuable forage crops and medicinal materials. Here, we conducted Illumina/Solexa sequencing to profile the transcriptome of L. corniculatus. We produced 26,492,952 short reads that corresponded to 2.38 gigabytes of total nucleotides. These reads were then assembled into 45,698 unigenes, of which a large number associated with secondary metabolism were annotated. In addition, we identified 2,998 unigenes based on homology with L. japonicus transcription factors (TFs) and grouped them into 55 families. Meanwhile, a comparison of four tag-based digital gene expression libraries, built from the flowers, pods, leaves, and roots, revealed distinct patterns of spatial expression of candidate unigenes in flavonoid biosynthesis. Based on these results, we identified many key enzymes from L. corniculatus which were different from reference genes of L. japonicus, and five TFs that are potential enhancers in flavonoid biosynthesis. Our results provide initial genetics resources that will be valuable in efforts to manipulate the flavonoid metabolic pathway in plants.

  18. P-HYDROXYPHENYLPYRUVATE DIOXYGENASE from Medicago sativa is involved in vitamin E biosynthesis and abscisic acid-mediated seed germination

    Science.gov (United States)

    Jiang, Jishan; Chen, Zhihong; Ban, Liping; Wu, Yudi; Huang, Jianping; Chu, Jinfang; Fang, Shuang; Wang, Zan; Gao, Hongwen; Wang, Xuemin

    2017-01-01

    P-HYDROXYPHENYLPYRUVATE DIOXYGENASE (HPPD) is the first committed enzyme involved in the biosynthesis of vitamin E, and is characterized by catalyzing the conversion of p-hydroxyphenyl pyruvate (HPP) to homogentisic acid (HGA). Here, an HPPD gene was cloned from Medicago sativa L. and designated MsHPPD, which was expressed at high levels in alfalfa leaves. PEG 6000 (polyethylene glycol), NaCl, abscisic acid and salicylic acid were shown to significantly induce MsHPPD expression, especially in the cotyledons and root tissues. Overexpression of MsHPPD was found to significantly increase the level of β-tocotrienol and the total vitamin E content in Arabidopsis seeds. Furthermore, these transgenic Arabidopsis seeds exhibited an accelerated germination time, compared with wild-type seeds under normal conditions, as well as under NaCl and ABA treatments. Meanwhile, the expression level of several genes associated with ABA biosynthesis (NCED3, NCED5 and NCED9) and the ABA signaling pathway (RAB18, ABI3 and ABI5) were significantly down-regulated in MsHPPD-overexpressing transgenic lines, as well as the total free ABA content. Taken together, these results demonstrate that MsHPPD functions not only in the vitamin E biosynthetic pathway, but also plays a critical role in seed germination via affecting ABA biosynthesis and signaling. PMID:28084442

  19. P-HYDROXYPHENYLPYRUVATE DIOXYGENASE from Medicago sativa is involved in vitamin E biosynthesis and abscisic acid-mediated seed germination.

    Science.gov (United States)

    Jiang, Jishan; Chen, Zhihong; Ban, Liping; Wu, Yudi; Huang, Jianping; Chu, Jinfang; Fang, Shuang; Wang, Zan; Gao, Hongwen; Wang, Xuemin

    2017-01-13

    P-HYDROXYPHENYLPYRUVATE DIOXYGENASE (HPPD) is the first committed enzyme involved in the biosynthesis of vitamin E, and is characterized by catalyzing the conversion of p-hydroxyphenyl pyruvate (HPP) to homogentisic acid (HGA). Here, an HPPD gene was cloned from Medicago sativa L. and designated MsHPPD, which was expressed at high levels in alfalfa leaves. PEG 6000 (polyethylene glycol), NaCl, abscisic acid and salicylic acid were shown to significantly induce MsHPPD expression, especially in the cotyledons and root tissues. Overexpression of MsHPPD was found to significantly increase the level of β-tocotrienol and the total vitamin E content in Arabidopsis seeds. Furthermore, these transgenic Arabidopsis seeds exhibited an accelerated germination time, compared with wild-type seeds under normal conditions, as well as under NaCl and ABA treatments. Meanwhile, the expression level of several genes associated with ABA biosynthesis (NCED3, NCED5 and NCED9) and the ABA signaling pathway (RAB18, ABI3 and ABI5) were significantly down-regulated in MsHPPD-overexpressing transgenic lines, as well as the total free ABA content. Taken together, these results demonstrate that MsHPPD functions not only in the vitamin E biosynthetic pathway, but also plays a critical role in seed germination via affecting ABA biosynthesis and signaling.

  20. Diagnosis of vertical root fractures in endodontically treated teeth utilising Digital Subtraction Radiography: A case series report.

    Science.gov (United States)

    Mikrogeorgis, Georgios; Eirinaki, Eleni; Kapralos, Vasileios; Koutroulis, Andreas; Lyroudia, Kleoniki; Pitas, Ioannis

    2017-12-11

    Vertical root fractures are commonly associated with root-filled teeth. Diagnosis is challenging because the clinical signs are not completely pathognomonic, and conventional periapical radiography is often unreliable. Digital subtraction radiography (DSR) is able to detect small radiographic changes between two successive radiographs by subtracting out consistent radiographic elements. Its use could possibly assist in the diagnostic procedure. Four cases are presented to demonstrate the potential use of DSR in the detection of vertical root fractures in endodontically treated teeth. After the digital subtractions had been carried out, a dark line in the body of the roots was distinguishable, raising the possibility of the presence of a vertical root fracture. The use of contrast enhancement and pseudocolouring techniques assisted with the diagnosis of vertical root fractures. DSR proved to be a useful diagnostic tool for the detection of vertical root fractures in these four clinical cases. © 2017 Australian Society of Endodontology Inc.

  1. Heteroconium chaetospira induces resistance to clubroot via upregulation of host genes involved in jasmonic acid, ethylene, and auxin biosynthesis.

    Directory of Open Access Journals (Sweden)

    Rachid Lahlali

    Full Text Available An endophytic fungus, Heteroconium chaetospira isolate BC2HB1 (Hc, suppressed clubroot (Plasmodiophora brassicae -Pb on canola in growth-cabinet trials. Confocal microscopy demonstrated that Hc penetrated canola roots and colonized cortical tissues. Based on qPCR analysis, the amount of Hc DNA found in canola roots at 14 days after treatment was negatively correlated (r = 0.92, P<0.001 with the severity of clubroot at 5 weeks after treatment at a low (2×10(5 spores pot(-1 but not high (2×10(5 spores pot(-1 dose of pathogen inoculum. Transcript levels of nine B. napus (Bn genes in roots treated with Hc plus Pb, Pb alone and a nontreated control were analyzed using qPCR supplemented with biochemical analysis for the activity of phenylalanine ammonia lyases (PAL. These genes encode enzymes involved in several biosynthetic pathways related potentially to plant defence. Hc plus Pb increased the activity of PAL but not that of the other two genes (BnCCR and BnOPCL involved also in phenylpropanoid biosynthesis, relative to Pb inoculation alone. In contrast, expression of several genes involved in the jasmonic acid (BnOPR2, ethylene (BnACO, auxin (BnAAO1, and PR-2 protein (BnPR-2 biosynthesis were upregulated by 63, 48, 3, and 3 fold, respectively, by Hc plus Pb over Pb alone. This indicates that these genes may be involved in inducing resistance in canola by Hc against clubroot. The upregulation of BnAAO1 appears to be related to both pathogenesis of clubroot and induced defence mechanisms in canola roots. This is the first report on regulation of specific host genes involved in induced plant resistance by a non-mycorrhizal endophyte.

  2. Regulation of sesquiterpenoid metabolism in recombinant and elicited Valeriana officinalis hairy roots.

    Science.gov (United States)

    Ricigliano, Vincent; Kumar, Santosh; Kinison, Scott; Brooks, Christopher; Nybo, S Eric; Chappell, Joe; Howarth, Dianella G

    2016-05-01

    The medicinal properties of Valerian (Valeriana officinalis) root preparations are attributed to the anxiolytic sesquiterpenoid valerenic acid and its biosynthetic precursors valerenal and valerenadiene, as well as the anti-inflammatory sesquiterpenoid β-caryophyllene. In order to study and engineer the biosynthesis of these pharmacologically active metabolites, a binary vector co-transformation system was developed for V. officinalis hairy roots. The relative expression levels and jasmonate-inducibility of a number of genes associated with sesquiterpenoid metabolism were profiled in roots: farnesyl pyrophosphate synthase (VoFPS), valerendiene synthase (VoVDS), germacrene C synthase (VoGCS), and a cytochrome P450 (CYP71D442) putatively associated with terpene metabolism based on sequence homology. Recombinant hairy root lines overexpressing VoFPS or VoVDS were generated and compared to control cultures. Overexpression of the VoFPS cDNA increased levels of the corresponding transcript 4- to 8-fold and sesquiterpene hydrocarbon accumulation by 1.5- to 4-fold. Overexpression of the VoVDS cDNA increased the corresponding transcript levels 5- to 9-fold and markedly increased yields of the oxygenated sesquiterpenoids valerenic acid and valerenal. Our findings suggest that the availability of cytoplasmic farnesyl diphosphate and valerenadiene are potential bottlenecks in Valeriana-specific sesquiterpenoid biosynthesis, which is also subject to regulation by methyl jasmonate elicitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Promoting scopolamine biosynthesis in transgenic Atropa belladonna plants with pmt and h6h overexpression under field conditions.

    Science.gov (United States)

    Xia, Ke; Liu, Xiaoqiang; Zhang, Qiaozhuo; Qiang, Wei; Guo, Jianjun; Lan, Xiaozhong; Chen, Min; Liao, Zhihua

    2016-09-01

    Atropa belladonna is one of the most important plant sources for producing pharmaceutical tropane alkaloids (TAs). T1 progeny of transgenic A. belladonna, in which putrescine N-methyltransferase (EC. 2.1.1.53) from Nicotiana tabacum (NtPMT) and hyoscyamine 6β-hydroxylase (EC. 1.14.11.14) from Hyoscyamus niger (HnH6H) were overexpressed, were established to investigate TA biosynthesis and distribution in ripe fruits, leaves, stems, primary roots and secondary roots under field conditions. Both NtPMT and HnH6H were detected at the transcriptional level in transgenic plants, whereas they were not detected in wild-type plants. The transgenes did not influence the root-specific expression patterns of endogenous TA biosynthetic genes in A. belladonna. All four endogenous TA biosynthetic genes (AbPMT, AbTRI, AbCYP80F1 and AbH6H) had the highest/exclusive expression levels in secondary roots, suggesting that TAs were mainly synthesized in secondary roots. T1 progeny of transgenic A. belladonna showed an impressive scopolamine-rich chemotype that greatly improved the pharmaceutical value of A. belladonna. The higher efficiency of hyoscyamine conversion was found in aerial than in underground parts. In aerial parts of transgenic plants, hyoscyamine was totally converted to downstream alkaloids, especially scopolamine. Hyoscyamine, anisodamine and scopolamine were detected in underground parts, but scopolamine and anisodamine were more abundant than hyoscyamine. The exclusively higher levels of anisodamine in roots suggested that it might be difficult for its translocation from root to aerial organs. T1 progeny of transgenic A. belladonna, which produces scopolamine at very high levels (2.94-5.13 mg g(-1)) in field conditions, can provide more valuable plant materials for scopolamine production. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Root reinforcement and slope bioengineering stabilization by Spanish Broom (Spartium junceum L.

    Directory of Open Access Journals (Sweden)

    F. Giadrossich

    2009-09-01

    Full Text Available The present paper deals with the root system's characteristics of Spanish Broom (Spartium junceum L., a species whose capacity for adaptating and resisting to drought is worth investigating. In particular, the aims of the study were 1 to investigate the plant's bio-mechanical aspects and 2 to verify whether root reinforcement and the field rooting ability of stem cuttings enhance its potential for use in slope stabilization and soil bio-engineering techniques, particularly in the Mediterranean areas. Single root specimens were sampled and tested for tensile strength, obtaining classic tensile strength-diameter relationships. Analysis were performed on the root systems in order to assess root density distribution. The Root Area Ratio (RAR was analyzed by taking both direct and indirect measurements, the latter relying on image processing. The data obtained were used to analyze the stability of an artificial slope (landfill and the root reinforcement. The measurement and calculation of mean root number, mean root diameter, RAR, root cohesion and Factor of safety are presented in order to distinguish the effect of plant origin and propagation. Furthermore, tests were performed to assess the possibility of agamic propagation (survival rate of root-ball endowed plants, rooting from stem cuttings. These tests confirmed that agamic propagation is difficult, even though roots were produced from some buried stems, and for practical purposes it has been ruled out. Our results show that Spanish Broom has good bio-mechanical characteristics with regard to slope stabilization, even in critical pedoclimatic conditions and where inclinations are quite steep, and it is effective on soil depths up to about 50 cm, in agreement with other studies on Mediterranean species. It is effective in slope stabilization, but less suitable for soil bio-engineering or for triggering natural plant succession.

  5. Brassinosteroid signaling-dependent root responses to prolonged elevated ambient temperature.

    Science.gov (United States)

    Martins, Sara; Montiel-Jorda, Alvaro; Cayrel, Anne; Huguet, Stéphanie; Roux, Christine Paysant-Le; Ljung, Karin; Vert, Grégory

    2017-08-21

    Due to their sessile nature, plants have to cope with and adjust to their fluctuating environment. Temperature elevation stimulates the growth of Arabidopsis aerial parts. This process is mediated by increased biosynthesis of the growth-promoting hormone auxin. How plant roots respond to elevated ambient temperature is however still elusive. Here we present strong evidence that temperature elevation impinges on brassinosteroid hormone signaling to alter root growth. We show that elevated temperature leads to increased root elongation, independently of auxin or factors known to drive temperature-mediated shoot growth. We further demonstrate that brassinosteroid signaling regulates root responses to elevated ambient temperature. Increased growth temperature specifically impacts on the level of the brassinosteroid receptor BRI1 to downregulate brassinosteroid signaling and mediate root elongation. Our results establish that BRI1 integrates temperature and brassinosteroid signaling to regulate root growth upon long-term changes in environmental conditions associated with global warming.Moderate heat stimulates the growth of Arabidopsis shoots in an auxin-dependent manner. Here, Martins et al. show that elevated ambient temperature modifies root growth by reducing the BRI1 brassinosteroid-receptor protein level and downregulating brassinosteroid signaling.

  6. Role of root hydrophobic barriers in salt exclusion of a mangrove plant Avicennia officinalis.

    Science.gov (United States)

    Krishnamurthy, Pannaga; Jyothi-Prakash, Pavithra A; Qin, Lin; He, Jie; Lin, Qingsong; Loh, Chiang-Shiong; Kumar, Prakash P

    2014-07-01

    Salt exclusion at the roots and salt secretion in the leaves were examined in a mangrove, Avicennia officinalis. The non-secretor mangrove Bruguiera cylindrica was used for comparative study of hydrophobic barrier formation in the roots. Bypass flow was reduced when seedlings were previously treated with high salt concentration. A biseriate exodermis was detected in the salt-treated roots, along with an enhanced deposition of hydrophobic barriers in the endodermis. These barriers reduced Na(+) loading into the xylem, accounting for a 90-95% salt exclusion in A. officinalis. Prominent barriers were found in the roots of B. cylindrica even in the absence of salt treatment. A cytochrome P450 gene that may regulate suberin biosynthesis was up-regulated within hours of salt treatment in A. officinalis roots and leaves, corresponding with increased suberin deposition. X-ray microanalysis showed preferential deposition of Na(+) and Cl(-) in the root cortex compared with the stele, suggesting that the endodermis is the primary site of salt exclusion. Enhanced salt secretion and increased suberin deposition surrounding the salt glands were seen in the leaves with salt treatment. Overall, these data show that the deposition of apoplastic barriers increases resistance to bypass flow leading to efficient salt exclusion at the roots in mangroves. © 2014 John Wiley & Sons Ltd.

  7. An efficient method of distinguishing chaos from noise

    International Nuclear Information System (INIS)

    It is an important problem in chaos theory whether an observed irregular signal is deterministic chaotic or stochastic. We propose an efficient method for distinguishing deterministic chaotic from stochastic time series for short scalar time series. We first investigate, with the increase of the embedding dimension, the changing trend of the distance between two points which stay close in phase space. And then, we obtain the differences between Gaussian white noise and deterministic chaotic time series underlying this method. Finally, numerical experiments are presented to testify the validity and robustness of the method. Simulation results indicate that our method can distinguish deterministic chaotic from stochastic time series effectively even when the data are short and contaminated. (general)

  8. Mastomys (rodentia: muridae) species distinguished by hemoglobin pattern differences.

    Science.gov (United States)

    Robbins, C B; Krebs, J W; Johnson, K M

    1983-05-01

    Hemoglobin electrophoresis patterns were found to be reliable markers for distinguishing two species of Mastomys in Sierra Leone having 32 and 38 chromosomes. All 32-chromosome animals exhibited a single hemoglobin pattern, whereas those with 38-chromosomes had four distinguishable patterns. Both karyotypes were present throughout Sierra Leone. The 38-chromosome species was more prevalent in the Guinea savanna zone to the north, while the 32-chromosome species was most dominant in human-modified high forest areas of the eastern and southern parts of the country. In almost all situations the 32-chromosome species was more common in houses than in bush habitats; the reverse was true for Mastomys having 38 chromosomes. Analysis of hemoglobin patterns thus becomes useful for species identification, and is necessary to understand the roles of the different Mastomys forms as reservoirs of human diseases, such as Lassa fever in West Africa.

  9. Can accretion disk properties distinguish gravastars from black holes?

    International Nuclear Information System (INIS)

    Harko, Tiberiu; Kovacs, Zoltan; Lobo, Francisco S N

    2009-01-01

    Gravastars, hypothetic astrophysical objects, consisting of a dark energy condensate surrounded by a strongly correlated thin shell of anisotropic matter, have been proposed as an alternative to the standard black hole picture of general relativity. Observationally distinguishing between astrophysical black holes and gravastars is a major challenge for this latter theoretical model. This is due to the fact that in static gravastars large stability regions (of the transition layer of these configurations) exist that are sufficiently close to the expected position of the event horizon, so that it would be difficult to distinguish the exterior geometry of gravastars from an astrophysical black hole. However, in the context of stationary and axially symmetrical geometries, a possibility of distinguishing gravastars from black holes is through the comparative study of thin accretion disks around rotating gravastars and Kerr-type black holes, respectively. In the present paper, we consider accretion disks around slowly rotating gravastars, with all the metric tensor components estimated up to the second order in the angular velocity. Due to the differences in the exterior geometry, the thermodynamic and electromagnetic properties of the disks (energy flux, temperature distribution and equilibrium radiation spectrum) are different for these two classes of compact objects, consequently giving clear observational signatures. In addition to this, it is also shown that the conversion efficiency of the accreting mass into radiation is always smaller than the conversion efficiency for black holes, i.e. gravastars provide a less efficient mechanism for converting mass to radiation than black holes. Thus, these observational signatures provide the possibility of clearly distinguishing rotating gravastars from Kerr-type black holes.

  10. Bringing to Market Technological Innovation: What Distinguishes Success from Failure

    OpenAIRE

    Frattini, Federico; Massis, Alfredo De; Chiesa, Vittorio; Cassia, Lucio; Campopiano, Giovanna

    2012-01-01

    Commercialization is a critical step in technological innovation. Nevertheless, many scholars believe that it is often the least well-managed activity of the whole innovation process. The launch stage seems to be particularly critical in high-technology markets because of the volatility, interconnectedness and the proliferation of new technologies they experience. However, academic and practitioners' literature has not, so far, developed a clear understanding of the factors that distinguish a...

  11. Distinguishing new physics scenarios with polarized electron and ...

    Indian Academy of Sciences (India)

    Distinguishing new physics scenarios. Figure 1. Left panel: ΛH vs. ΛAA confusion region from e+e− → e+e−. Right panel: ΛLL vs. ΛRR confusion region from e+e− → l+l− (l = µ, τ). √ s = 0.5 TeV, Lint = 100 fb−1. the identification reaches are rather high compared to the current bounds, depend- ing on energy and luminosity, ...

  12. Phylogenetic and evolutionary patterns in microbial carotenoid biosynthesis are revealed by comparative genomics.

    Directory of Open Access Journals (Sweden)

    Jonathan L Klassen

    previously. This phylogenetic framework is applicable to understanding the evolution of specific carotenoid biosynthetic proteins or the unique characteristics of carotenoid biosynthetic evolution in a specific phylogenetic lineage. Together, these analyses suggest a "bramble" model for microbial carotenoid biosynthesis whereby later biosynthetic steps exhibit greater evolutionary plasticity and reticulation compared to those closer to the biosynthetic "root". Structural diversification may be constrained ("trimmed" where selection is strong, but less so where selection is weaker. These analyses also highlight likely productive avenues for future research and bioprospecting by identifying both gaps in current knowledge and taxa which may particularly facilitate carotenoid diversification.

  13. The strigolactone biosynthesis gene DWARF27 is co-opted in rhizobium symbiosis.

    Science.gov (United States)

    van Zeijl, Arjan; Liu, Wei; Xiao, Ting Ting; Kohlen, Wouter; Yang, Wei-Cai; Bisseling, Ton; Geurts, René

    2015-10-26

    Strigolactones are a class of plant hormones whose biosynthesis is activated in response to phosphate starvation. This involves several enzymes, including the carotenoid cleavage dioxygenases 7 (CCD7) and CCD8 and the carotenoid isomerase DWARF27 (D27). D27 expression is known to be responsive to phosphate starvation. In Medicago truncatula and rice (Oryza sativa) this transcriptional response requires the GRAS-type proteins NSP1 and NSP2; both proteins are essential for rhizobium induced root nodule formation in legumes. In line with this, we questioned whether MtNSP1-MtNSP2 dependent MtD27 regulation is co-opted in rhizobium symbiosis. We provide evidence that MtD27 is involved in strigolactone biosynthesis in M. truncatula roots upon phosphate stress. Spatiotemporal expression studies revealed that this gene is also highly expressed in nodule primordia and subsequently becomes restricted to the meristem and distal infection zone of a mature nodules. A similar expression pattern was found for MtCCD7 and MtCCD8. Rhizobium lipo-chitooligosaccharide (LCO) application experiments revealed that of these genes MtD27 is most responsive in an MtNSP1 and MtNSP2 dependent manner. Symbiotic expression of MtD27 requires components of the symbiosis signaling pathway; including MtDMI1, MtDMI2, MtDMI3/MtCCaMK and in part MtERN1. This in contrast to MtD27 expression upon phosphate starvation, which only requires MtNSP1 and MtNSP2. Our data show that the phosphate-starvation responsive strigolactone biosynthesis gene MtD27 is also rapidly induced by rhizobium LCO signals in an MtNSP1 and MtNSP2-dependent manner. Additionally, we show that MtD27 is co-expressed with MtCCD7 and MtCCD8 in nodule primordia and in the infection zone of mature nodules.

  14. Root hairs increase root exudation and rhizosphere extension

    Science.gov (United States)

    Holz, Maire; Zarebandanadkouki, Mohsen; Kuzyakov, Yakov; Carmintati, Andrea

    2017-04-01

    Plant roots employ various mechanisms to increase their access to limited soil resources. An example of such strategies is the production of root hairs. Root hairs extend the root surface and therefore increase the access to nutrients. Additionally, carbon release from root hairs might facilitate nutrient uptake by spreading of carbon in the rhizosphere and enhancing microbial activity. The aim of this study was to test: i) how root hairs change the allocation of carbon in the soil-plant system; ii) whether root hairs exude carbon into the soil and iii) how differences in C release between plants with and without root hairs affect rhizosphere extension. We grew barley plants with and without root hairs (wild type: WT, bald root barley: brb) in rhizoboxes filled with a sandy soil. Root elongation was monitored over time. After 4 weeks of growth, plants were labelled with 14CO2. A filter paper was placed on the soil surface before labelling and was removed after 36 h. 14C imaging of the soil surface and of the filter paper was used to quantify the allocation of 14C into the roots and the exudation of 14C, respectively. Plants were sampled destructively one day after labeling to quantify 14C in the plant-soil system. 14CO2 release from soil over time (17 d) was quantified by trapping CO2 in NaOH with an additional subset of plants. WT and brb plants had a similar aboveground biomass and allocated similar amounts of 14C into shoots (170 KBq for WT; 152 KBq for brb) and roots one day after labelling. Biomass of root, rhizosphere soil as well as root elongation were lower for brb compared to the wild type. WT plants transported more C from the shoots to the roots (22.8% for WT; 13.8% for brb) and from the root into the rhizosphere (8.8% for WT 3.5% for brb). Yet lower amounts of 14CO2 were released from soil over time for WT. Radial and longitudinal rhizosphere extension was increased for WT compared to brb (4.7 vs. 2.6 mm; 5.6 vs. 3.1 cm). The total exudation which was

  15. Arabidopsis and Maize RidA Proteins Preempt Reactive Enamine/Imine Damage to Branched-Chain Amino Acid Biosynthesis in Plastids[C][W][OPEN

    Science.gov (United States)

    Niehaus, Thomas D.; Nguyen, Thuy N.D.; Gidda, Satinder K.; ElBadawi-Sidhu, Mona; Lambrecht, Jennifer A.; McCarty, Donald R.; Downs, Diana M.; Cooper, Arthur J.L.; Fiehn, Oliver; Mullen, Robert T.; Hanson, Andrew D.

    2014-01-01

    RidA (for Reactive Intermediate Deaminase A) proteins are ubiquitous, yet their function in eukaryotes is unclear. It is known that deleting Salmonella enterica ridA causes Ser sensitivity and that S. enterica RidA and its homologs from other organisms hydrolyze the enamine/imine intermediates that Thr dehydratase forms from Ser or Thr. In S. enterica, the Ser-derived enamine/imine inactivates a branched-chain aminotransferase; RidA prevents this damage. Arabidopsis thaliana and maize (Zea mays) have a RidA homolog that is predicted to be plastidial. Expression of either homolog complemented the Ser sensitivity of the S. enterica ridA mutant. The purified proteins hydrolyzed the enamines/imines formed by Thr dehydratase from Ser or Thr and protected the Arabidopsis plastidial branched-chain aminotransferase BCAT3 from inactivation by the Ser-derived enamine/imine. In vitro chloroplast import assays and in vivo localization of green fluorescent protein fusions showed that Arabidopsis RidA and Thr dehydratase are chloroplast targeted. Disrupting Arabidopsis RidA reduced root growth and raised the root and shoot levels of the branched-chain amino acid biosynthesis intermediate 2-oxobutanoate; Ser treatment exacerbated these effects in roots. Supplying Ile reversed the root growth defect. These results indicate that plastidial RidA proteins can preempt damage to BCAT3 and Ile biosynthesis by hydrolyzing the Ser-derived enamine/imine product of Thr dehydratase. PMID:25070638

  16. Arbuscular mycorrhiza-specific enzymes FatM and RAM2 fine-tune lipid biosynthesis to promote development of arbuscular mycorrhiza.

    Science.gov (United States)

    Bravo, Armando; Brands, Mathias; Wewer, Vera; Dörmann, Peter; Harrison, Maria J

    2017-06-01

    During arbuscular mycorrhizal symbiosis (AMS), considerable amounts of lipids are generated, modified and moved within the cell to accommodate the fungus in the root, and it has also been suggested that lipids are delivered to the fungus. To determine the mechanisms by which root cells redirect lipid biosynthesis during AMS we analyzed the roles of two lipid biosynthetic enzymes (FatM and RAM2) and an ABC transporter (STR) that are required for symbiosis and conserved uniquely in plants that engage in AMS. Complementation analyses indicated that the biochemical function of FatM overlaps with that of other Fat thioesterases, in particular FatB. The essential role of FatM in AMS was a consequence of timing and magnitude of its expression. Lipid profiles of fatm and ram2 suggested that FatM increases the outflow of 16:0 fatty acids from the plastid, for subsequent use by RAM2 to produce 16:0 β-monoacylglycerol. Thus, during AMS, high-level, specific expression of key lipid biosynthetic enzymes located in the plastid and the endoplasmic reticulum enables the root cell to fine-tune lipid biosynthesis to increase the production of β-monoacylglycerols. We propose a model in which β-monoacylglycerols, or a derivative thereof, are exported out of the root cell across the periarbuscular membrane for ultimate use by the fungus. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  17. Distinguishing snoring sounds from breath sounds: a straightforward matter?

    Science.gov (United States)

    Rohrmeier, Christian; Herzog, Michael; Ettl, Tobias; Kuehnel, Thomas S

    2014-03-01

    Although snoring is a common problem, no unequivocal definition yet exists for this acoustic phenomenon. The primary study objective was to investigate whether snoring sounds can be distinguished at all clearly from breath sounds. Our secondary objective was to evaluate whether the sound pressure level in common use and psychoacoustic parameters are suitable for making this distinction. Twenty-five subjects exposed to 55 sound sequences were asked to decide whether these were breath sounds or snoring sounds, and to indicate how certain they were about their decision. The sound pressure level and the psychoacoustic parameters of loudness, sharpness, roughness, and fluctuation strength were then analyzed, and psychoacoustic annoyance was calculated from these parameters. Sixteen percent of the sound sequences could not be classified unequivocally, although the individual raters stated that they were still moderately certain about their decision. The sound pressure level and psychoacoustic parameters were capable of distinguishing between breath sounds and snoring sounds. The optimum for sensitivity and specificity was 76.9 and 78.8 %, respectively. Because snoring appears to be a subjective impression, at least in part, a generally valid acoustic definition therefore seems to be impossible. The sound pressure level and psychoacoustic parameters are suitable for distinguishing between breath sounds and snoring sounds. Nevertheless, when interpreting results, the only moderate validity of these parameters due to the absence of a universally valid definition of snoring should be taken into account.

  18. Optimization of In Vitro Techniques for Distinguishing between Live and Dead Second Stage Juveniles of Heterodera glycines and Meloidogyne incognita.

    Directory of Open Access Journals (Sweden)

    Ni Xiang

    Full Text Available Heterodera glycines (Soybean Cyst nematode, or SCN and Meloidogyne incognita (Root-Knot nematode, or RKN are two damaging plant-parasitic nematodes on important field crops. Developing a quick method to distinguish between live and dead SCN and RKN second stage juveniles (J2 is vital for high throughput screening of pesticides or biological compounds against SCN and RKN. The in vitro assays were conducted in 96-well plates to determine the optimum chemical stimulus to distinguish between live and dead SCN and RKN J2. Sodium carbonate (Na2CO3, sodium bicarbonate (NaHCO3, and sodium hydroxide (NaOH were evaluated for the nematode response to see if these compounds can help distinguish between viable from the dead J2. Results indicated that live SCN J2 responded equally (P ≤ 0.05 to 1 μl Na2CO3 and 10 μl NaHCO3 in 100 μl of water at pH = 10. Live SCN J2 responded by twisting their bodies in a curling shape and increasing rate of movements within 2 minutes of exposure. The twisting activity continued for up to 30 minutes. Live RKN J2 responded by increasing activity with the application of 1 μl NaOH in 100 μl of water at pH = 10 also in the 2 minutes to 30 minutes time frame. Furthermore, in growth chamber tests to confirm the infectivity of live SCN. The live SCN as determined by exposure to 1 μl of Na2CO3 indicated 60.5% of the SCN J2 were alive and of those, 29.5% were infective and entered the soybean roots. The 1 μl of NaOH stimulus revealed that 75.2% RKN J2 were alive and of those, 14.9% were infective and entered soybean roots. These results confirmed that 1 μl of Na2CO3 added to 100 μl suspension of SCN J2 and 1 μl of NaOH added to 100 μl suspension of RKN J2 are the effective stimuli for rapidly distinguishing between live and dead SCN and RKN J2 in vitro. SCN and RKN J2 responded differently to different compounds.

  19. Hydraulic conductivity of rice roots.

    Science.gov (United States)

    Miyamoto, N; Steudle, E; Hirasawa, T; Lafitte, R

    2001-09-01

    A pressure chamber and a root pressure probe technique have been used to measure hydraulic conductivities of rice roots (root Lp(r) per m(2) of root surface area). Young plants of two rice (Oryza sativa L.) varieties (an upland variety, cv. Azucena and a lowland variety, cv. IR64) were grown for 31-40 d in 12 h days with 500 micromol m(-2) s(-1) PAR and day/night temperatures of 27 degrees C and 22 degrees C. Root Lp(r) was measured under conditions of steady-state and transient water flow. Different growth conditions (hydroponic and aeroponic culture) did not cause visible differences in root anatomy in either variety. Values of root Lp(r) obtained from hydraulic (hydrostatic) and osmotic water flow were of the order of 10(-8) m s(-1) MPa(-1) and were similar when using the different techniques. In comparison with other herbaceous species, rice roots tended to have a higher hydraulic resistance of the roots per unit root surface area. The data suggest that the low overall hydraulic conductivity of rice roots is caused by the existence of apoplastic barriers in the outer root parts (exodermis and sclerenchymatous (fibre) tissue) and by a strongly developed endodermis rather than by the existence of aerenchyma. According to the composite transport model of the root, the ability to adapt to higher transpirational demands from the shoot should be limited for rice because there were minimal changes in root Lp(r) depending on whether hydrostatic or osmotic forces were acting. It is concluded that this may be one of the reasons why rice suffers from water shortage in the shoot even in flooded fields.

  20. Engineering E. coli for caffeic acid biosynthesis from renewable sugars.

    Science.gov (United States)

    Zhang, Haoran; Stephanopoulos, Gregory

    2013-04-01

    Caffeic acid is a valuable aromatic compound that possesses many important pharmacological activities. In structure, caffeic acid belongs to the hydroxycinnamic acid family and can be biosynthesized from the aromatic amino acid tyrosine. In the present paper, the caffeic acid biosynthesis pathway was reconstituted in engineered Escherichia coli to produce caffeic acid from simple biomass sugar glucose and xylose. Different engineering approaches were utilized to optimize the production. Specifically, two parallel biosynthesis routes leading from tyrosine to caffeic acid were studied. The copy number of the intermediate biosynthesis genes was varied to find appropriate gene doses for caffeic acid biosynthesis. Three different media, including a MOPS medium, a synthetic medium, and a rich medium, were also examined to improve the production. The highest specific caffeic acid production achieved was 38 mg/L/OD. Lastly, cultivation of engineered E. coli in a bioreactor resulted in a production of 106 mg/L caffeic acid after 4 days.

  1. Biosynthesis, regulation and biological role of strigolactones in rice

    NARCIS (Netherlands)

    Moura Luis Cardoso, De C.S.

    2014-01-01

    In her thesis Catarina Cardoso studied strigolactone biosynthesis in rice. Strigolactones are multifunctional compounds produced by plants. They are plant hormones that regulate plant architecture, but in addition plants release strigolactones into the soil to communicate and initiate beneficial

  2. Transcriptome analysis of Panax vietnamensis var. fuscidicus discovers putative ocotillol-type ginsenosides biosynthesis genes and genetic markers.

    Science.gov (United States)

    Zhang, Guang-Hui; Ma, Chun-Hua; Zhang, Jia-Jin; Chen, Jun-Wen; Tang, Qing-Yan; He, Mu-Han; Xu, Xiang-Zeng; Jiang, Ni-Hao; Yang, Sheng-Chao

    2015-03-08

    P. vietnamensis var. fuscidiscus, called "Yesanqi" in Chinese, is a new variety of P. vietnamensis, which was first found in Jinping County, the southern part of Yunnan Province, China. Compared with other Panax plants, this species contains higher content of ocotillol-type saponin, majonoside R2. Despite the pharmacological importance of ocotillol-type saponins, little is known about their biosynthesis in plants. Hence, P. vietnamensis var. fuscidiscus is a suitable medicinal herbal plant species to study biosynthesis of ocotillol-type saponins. In addition, the available genomic information of this important herbal plant is lacking. To investigate the P. vietnamensis var. fuscidiscus transcriptome, Illumina HiSeq™ 2000 sequencing platform was employed. We produced 114,703,210 clean reads, assembled into 126,758 unigenes, with an average length of 1,304 bp and N50 of 2,108 bp. Among these 126,758 unigenes, 85,214 unigenes (67.23%) were annotated based on the information available from the public databases. The transcripts encoding the known enzymes involved in triterpenoid saponins biosynthesis were identified in our Illumina dataset. A full-length cDNA of three Squalene epoxidase (SE) genes were obtained using reverse transcription PCR (RT-PCR) and the expression patterns of ten unigenes were analyzed by reverse transcription quantitative real-time PCR (RT-qPCR). Furthermore, 15 candidate cytochrome P450 genes and 17 candidate UDP-glycosyltransferase genes most likely to involve in triterpenoid saponins biosynthesis pathway were discovered from transcriptome sequencing of P. vietnamensis var. fuscidiscus. We further analyzed the data and found 21,320 simple sequence repeats (SSRs), 30 primer pairs for SSRs were randomly selected for validation of the amplification and polymorphism in 13 P. vietnamensis var. fuscidiscus accessions. Meanwhile, five major triterpene saponins in roots of P. vietnamensis var. fuscidicus were determined using high performance

  3. Cylindrocarpon root rot: multi-gene analysis reveals novel species within the Ilyonectria radicicola species complex

    NARCIS (Netherlands)

    Cabral, A.; Groenewald, J.Z.; Rego, C.; Oliveira, H.; Crous, P.W.

    2012-01-01

    Ilyonectria radicicola and its Cylindrocarpon-like anamorph represent a species complex that is commonly associated with root rot disease symptoms on a range of hosts. During the course of this study, several species could be distinguished from I. radicicola sensu stricto based on morphological and

  4. NAD+ biosynthesis, aging, and disease [version 1; referees: 2 approved

    OpenAIRE

    Sean Johnson; Shin–ichiro Imai

    2018-01-01

    Nicotinamide adenine dinucleotide (NAD+) biosynthesis and its regulation have recently been attracting markedly increasing interest. Aging is marked by a systemic decrease in NAD+ across multiple tissues. The dysfunction of NAD+ biosynthesis plays a critical role in the pathophysiologies of multiple diseases, including age-associated metabolic disorders, neurodegenerative diseases, and mental disorders. As downstream effectors, NAD+-dependent enzymes, such as sirtuins, are involved in the pro...

  5. PgLOX6 encoding a lipoxygenase contributes to jasmonic acid biosynthesis and ginsenoside production in Panax ginseng.

    Science.gov (United States)

    Rahimi, Shadi; Kim, Yu-Jin; Sukweenadhi, Johan; Zhang, Dabing; Yang, Deok-Chun

    2016-11-01

    Ginsenosides, the valuable pharmaceutical compounds in Panax ginseng, are triterpene saponins that occur mainly in ginseng plants. It was shown that in vitro treatment with the phytohormone jasmonic acid (JA) is able to increase ginsenoside production in ginseng plants. To understand the molecular link between JA biosynthesis and ginsenoside biosynthesis, we identified a JA biosynthetic 13-lipoxygenase gene (PgLOX6) in P. ginseng that promotes ginsenoside production. The expression of PgLOX6 was high in vascular bundles, which corresponds with expression of ginsenoside biosynthetic genes. Consistent with the role of PgLOX6 in synthesizing JA and promoting ginsenoside synthesis, transgenic plants overexpressing PgLOX6 in Arabidopsis had increased amounts of JA and methyl jasmonate (MJ), increased expression of triterpene biosynthetic genes such as squalene synthase (AtSS1) and squalene epoxidase (AtSE1), and increased squalene content. Moreover, transgenic ginseng roots overexpressing PgLOX6 had around 1.4-fold increased ginsenoside content and upregulation of ginsenoside biosynthesis-related genes including PgSS1, PgSE1, and dammarenediol synthase (PgDDS), which is similar to that of treatment with MJ. However, MJ treatment of transgenic ginseng significantly enhanced JA and MJ, associated with a 2.8-fold increase of ginsenoside content compared with the non-treated, non-transgenic control plant, which was 1.4 times higher than the MJ treatment effect on non-transgenic plants. These results demonstrate that PgLOX6 is responsible for the biosynthesis of JA and promotion of the production of triterpenoid saponin through up-regulating the expression of ginsenoside biosynthetic genes. This work provides insight into the role of JA in biosynthesizing secondary metabolites and provides a molecular tool for increasing ginsenoside production. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  6. The Arabidopsis thiamin-deficient mutant pale green1 lacks thiamin monophosphate phosphatase of the vitamin B1 biosynthesis pathway.

    Science.gov (United States)

    Hsieh, Wei-Yu; Liao, Jo-Chien; Wang, Hsin-Tzu; Hung, Tzu-Huan; Tseng, Ching-Chih; Chung, Tsui-Yun; Hsieh, Ming-Hsiun

    2017-07-01

    Thiamin diphosphate (TPP, vitamin B 1 ) is an essential coenzyme present in all organisms. Animals obtain TPP from their diets, but plants synthesize TPPde novo. We isolated and characterized an Arabidopsis pale green1 (pale1) mutant that contained higher concentrations of thiamin monophosphate (TMP) and less thiamin and TPP than the wild type. Supplementation with thiamin, but not the thiazole and pyrimidine precursors, rescued the mutant phenotype, indicating that the pale1 mutant is a thiamin-deficient mutant. Map-based cloning and whole-genome sequencing revealed that the pale1 mutant has a mutation in At5g32470 encoding a TMP phosphatase of the TPP biosynthesis pathway. We further confirmed that the mutation of At5g32470 is responsible for the mutant phenotypes by complementing the pale1 mutant with constructs overexpressing full-length At5g32470. Most plant TPP biosynthetic enzymes are located in the chloroplasts and cytosol, but At5g32470-GFP localized to the mitochondrion of the root, hypocotyl, mesophyll and guard cells of the 35S:At5g32470-GFP complemented plants. The subcellular localization of a functional TMP phosphatase suggests that the complete vitamin B1 biosynthesis pathway may involve the chloroplasts, mitochondria and cytosol in plants. Analysis of PALE1 promoter-uidA activity revealed that PALE1 is mainly expressed in vascular tissues of Arabidopsis seedlings. Quantitative RT-PCR analysis of TPP biosynthesis genes and genes encoding the TPP-dependent enzymes pyruvate dehydrogenase, α-ketoglutarate dehydrogenase and transketolase revealed that the transcript levels of these genes were upregulated in the pale1 mutant. These results suggest that endogenous levels of TPP may affect the expression of genes involved in TPP biosynthesis and TPP-dependent enzymes. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  7. Proline accumulation in leaves of Periploca sepium via both biosynthesis up-regulation and transport during recovery from severe drought.

    Directory of Open Access Journals (Sweden)

    Yuyan An

    Full Text Available Drought resistance and recovery ability are two important requisites for plant adaptation to drought environments. Proline (Pro metabolism has been a major concern in plant drought tolerance. However, roles of Pro metabolism in plant recovery ability from severe drought stress are largely unexplored. Periploca sepium Bunge has gained increasing attention for its adaptation to dry environments. Here, we investigated Pro metabolism in different tissues of P. sepium seedlings in the course of drought stress and recovery. We found that leaf Pro metabolism response during post-drought recovery was dependant on drought severity. Pro biosynthesis was down-regulated during recovery from -0.4 MPa but increased continually and notably during recovery from -1.0 MPa. Significant correlation between Pro concentration and Δ1-pyrroline-5-carboxylate synthetase activity indicates that Glutamate pathway is the predominant synthesis route during both drought and re-watering periods. Ornithine δ-aminotransferase activity was up-regulated significantly only during recovery from -1.0 MPa, suggesting positive contribution of ornithine pathway to improving plant recovery capacity from severe drought. In addition to up-regulation of biosynthesis, Pro transport from stems and roots also contributed to high Pro accumulation in leaves and new buds during recovery from -1.0 MPa, as indicated by the combined analysis of Pro concentration and its biosynthesis in stems, roots and new buds. Except its known roles as energy, carbon and nitrogen sources for plant rapid recovery, significant positive correlation between Pro concentration and total antioxidant activity indicates that Pro accumulation can also promote plant damage repair ability by up-regulating antioxidant activity during recovery from severe drought stress.

  8. MsmiR156 affects global gene expression and promotes root regenerative capacity and nitrogen fixation activity in alfalfa.

    Science.gov (United States)

    Aung, Banyar; Gao, Ruimin; Gruber, Margaret Y; Yuan, Ze-Chun; Sumarah, Mark; Hannoufa, Abdelali

    2017-08-01

    MicroRNA156 (miR156) regulates a network of downstream genes to affect plant growth and development. We previously generated alfalfa (Medicago sativa) plants that overexpress homologous miR156 (MsmiR156OE), and identified three of its SPL target genes. These plants exhibited increased vegetative yield, delayed flowering and longer roots. In this study, we aimed to elucidate the effect of miR156 on the root system, including effect on nodulation and nitrogen fixation. We found that MsmiR156 overexpression increases root regeneration capacity in alfalfa, but with little effect on root biomass at the early stages of root development. MsmiR156 also promotes nitrogen fixation activity by upregulating expression of nitrogenase-related genes FixK, NifA and RpoH in roots inoculated with Sinorrhizobium meliloti. Furthermore, we conducted transcriptomics analysis of MsmiR156OE alfalfa roots and identified differentially expressed genes belonging to 132 different functional categories, including plant cell wall organization, peptidyl-hypusine synthesis, and response to water stress. Expression analysis also revealed miR156 effects on genes involved in nodulation, root development and phytohormone biosynthesis. The present findings suggest that miR156 regulates root development and nitrogen fixation activity. Taken together, these findings highlight the important role that miR156 may play as a tool in the biotechnological improvement of alfalfa, and potentially other crops.

  9. Auxin secretion by Bacillus amyloliquefaciens FZB42 both stimulates root exudation and limits phosphorus uptake in Triticum aestivum

    Science.gov (United States)

    2014-01-01

    Background The use of auxin-producing rhizosphere bacteria as agricultural products promises increased root production and therefore greater phosphate (Pi) uptake. Whilst such bacteria promote root production in vitro, the nature of the bacteria-plant interaction in live soil, particularly concerning any effects on nutrient uptake, are not known. This study uses Bacillus amyloliquefaciens FZB42, an auxin-producing rhizobacterium, as a dressing on Triticum aestivum seeds. It then examines the effects on root production, Pi uptake, Pi-related gene expression and organic carbon (C) exudation. Results Seed treatment with B. amyloliquefaciens FZB42 increased root production at low environmental Pi concentrations, but significantly repressed root Pi uptake. This coincided with an auxin-mediated reduction in expression of the Pi transporters TaPHT1.8 and TaPHT1.10. Applied exogenous auxin also triggered an increase in root C exudation. At high external Pi concentrations, root production was promoted by B. amyloliquefaciens FZB42, but Pi uptake was unaffected. Conclusions We conclude that, alongside promoting root production, auxin biosynthesis by B. amyloliquefaciens FZB42 both re-models Pi transporter expression and elevates organic C exudation. This shows the potential importance of rhizobacterial-derived auxin following colonisation of root surfaces, and the nature of this bacteria-plant interaction in soil. PMID:24558978

  10. [Effects of fertilization on fine root diameter, root length and specific root length in Larix kaempferi plantation].

    Science.gov (United States)

    Yu, Li-zhong; Ding, Guo-quan; Shi, Jian-wei; Yu, Shui-qiang; Zhu, Jiao-jun; Zhao, Lian-fu

    2007-05-01

    With 16 years old Larix kaempfersoil plantation in the mountainous area of eastern Liaoning Province as test object, this paper studied the effects of fertilization on the fine root diameter, root length, and specific root length (SRL) of the first to fifth order roots. The results showed that with ascending root orders, the mean fine root diameter and root length increased, while the SRL decreased significantly. Among the five order roots, the first order roots were the thinnest in diameter, the shortest in length, and the highest in SRL, but the fifth order roots were in reverse. The variance coefficients for the fine root diameter, root length, and SRL increased from the first to the fifth order roots. Except for the first order roots, soil depth had no significant influence on the fine root diameter, root length and SRL. Fertilization affected the fine root diameter, root length, and SRL of the first and the second order roots significantly, hut had little effects on other order roots. N fertilization decreased the mean diameter of the first and the second order roots significantly, and N or N + P fertilization decreased the mean length of the first order roots in surface soil (0-10 cm) significantly. The SRL of the first order roots in surface soil increased significantly under N fertilization.

  11. Expression of Root-Related Transcription Factors Associated with Flooding Tolerance of Soybean (Glycine max

    Directory of Open Access Journals (Sweden)

    Babu Valliyodan

    2014-09-01

    Full Text Available Much research has been conducted on the changes in gene expression of the model plant Arabidopsis to low-oxygen stress. Flooding results in a low oxygen environment in the root zone. However, there is ample evidence that tolerance to soil flooding is more than tolerance to low oxygen alone. In this study, we investigated the physiological response and differential expression of root-related transcription factors (TFs associated with the tolerance of soybean plants to soil flooding. Differential responses of PI408105A and S99-2281 plants to ten days of soil flooding were evaluated at physiological, morphological and anatomical levels. Gene expression underlying the tolerance response was investigated using qRT-PCR of root-related TFs, known anaerobic genes, and housekeeping genes. Biomass of flood-sensitive S99-2281 roots remained unchanged during the entire 10 days of flooding. Flood-tolerant PI408105A plants exhibited recovery of root growth after 3 days of flooding. Flooding induced the development of aerenchyma and adventitious roots more rapidly in the flood-tolerant than the flood-sensitive genotype. Roots of tolerant plants also contained more ATP than roots of sensitive plants at the 7th and 10th days of flooding. Quantitative transcript analysis identified 132 genes differentially expressed between the two genotypes at one or more time points of flooding. Expression of genes related to the ethylene biosynthesis pathway and formation of adventitious roots was induced earlier and to higher levels in roots of the flood-tolerant genotype. Three potential flood-tolerance TFs which were differentially expressed between the two genotypes during the entire 10-day flooding duration were identified. This study confirmed the expression of anaerobic genes in response to soil flooding. Additionally, the differential expression of TFs associated with soil flooding tolerance was not qualitative but quantitative and temporal. Functional analyses of

  12. The Roots of Beowulf

    Science.gov (United States)

    Fischer, James R.

    2014-01-01

    The first Beowulf Linux commodity cluster was constructed at NASA's Goddard Space Flight Center in 1994 and its origins are a part of the folklore of high-end computing. In fact, the conditions within Goddard that brought the idea into being were shaped by rich historical roots, strategic pressures brought on by the ramp up of the Federal High-Performance Computing and Communications Program, growth of the open software movement, microprocessor performance trends, and the vision of key technologists. This multifaceted story is told here for the first time from the point of view of NASA project management.

  13. Fenarimol, a Pyrimidine-Type Fungicide, Inhibits Brassinosteroid Biosynthesis

    Directory of Open Access Journals (Sweden)

    Keimei Oh

    2015-07-01

    Full Text Available The plant steroid hormone brassinosteroids (BRs are important signal mediators that regulate broad aspects of plant growth and development. With the discovery of brassinoazole (Brz, the first specific inhibitor of BR biosynthesis, several triazole-type BR biosynthesis inhibitors have been developed. In this article, we report that fenarimol (FM, a pyrimidine-type fungicide, exhibits potent inhibitory activity against BR biosynthesis. FM induces dwarfism and the open cotyledon phenotype of Arabidopsis seedlings in the dark. The IC50 value for FM to inhibit stem elongation of Arabidopsis seedlings grown in the dark was approximately 1.8 ± 0.2 μM. FM-induced dwarfism of Arabidopsis seedlings could be restored by brassinolide (BL but not by gibberellin (GA. Assessment of the target site of FM in BR biosynthesis by feeding BR biosynthesis intermediates indicated that FM interferes with the side chain hydroxylation of BR biosynthesis from campestanol to teasterone. Determination of the binding affinity of FM to purified recombinant CYP90D1 indicated that FM induced a typical type II binding spectrum with a Kd value of approximately 0.79 μM. Quantitative real-time PCR analysis of the expression level of the BR responsive gene in Arabidopsis seedlings indicated that FM induces the BR deficiency in Arabidopsis.

  14. Lignan formation in hairy root cultures of Edelweiss (Leontopodium nivale ssp. alpinum (Cass.) Greuter)

    Science.gov (United States)

    Wawrosch, Christoph; Schwaiger, Stefan; Stuppner, Hermann; Kopp, Brigitte

    2014-01-01

    A hairy root line of Edelweiss (Leontopodium nivale ssp. alpinum (Cass.) Greuter) was obtained upon transformation with Agrobacterium rhizogenes strain ATCC15834. Elicitation of this line with silver nitrate, sucrose, methyl jasmonate and yeast extract at various concentrations in most cases resulted in a stimulation of lignan biosynthesis. Through elicitation with 6% sucrose the roots accumulated the pharmacologically active lignans leoligin and 5-methoxy-leoligin at levels of 0.0678% and 0.0372%, respectively, without significant growth inhibition. These lignan levels were comparable to those found in intact roots of cultivated Edelweiss. The biotechnological production of leoligin could be an attractive option for the continuous, field culture-independent production of the valuable secondary metabolites leoligin and 5-methoxy-leoligin. PMID:24932777

  15. A hydraulic signal in root-to-shoot signalling of water shortage.

    Science.gov (United States)

    Christmann, Alexander; Weiler, Elmar W; Steudle, Ernst; Grill, Erwin

    2007-10-01

    Photosynthesis and biomass production of plants are controlled by the water status of the soil. Upon soil drying, plants can reduce water consumption by minimizing transpiration through stomata, the closable pores of the leaf. The phytohormone abscisic acid (ABA) mediates stomatal closure, and is the assigned signal for communicating water deficit from the root to the shoot. However, our study does not support ABA as the proposed long-distance signal. The shoot response to limited soil water supply is not affected by the capacity to generate ABA in the root; however, the response does require ABA biosynthesis and signalling in the shoot. Soil water stress elicits a hydraulic response in the shoot, which precedes ABA signalling and stomatal closure. Attenuation of the hydraulic response in various plants prevented long-distance signalling of water stress, consistent with root-to-shoot communication by a hydraulic signal.

  16. Gibberellin regulates infection and colonization of host roots by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Takeda, Naoya; Handa, Yoshihiro; Tsuzuki, Syusaku; Kojima, Mikiko; Sakakibara, Hitoshi; Kawaguchi, Masayoshi

    2015-01-01

    Arbuscular mycorrhiza (AM) is established by the entry of AM fungi into the host plant roots and the formation of symbiotic structures called arbuscules. The host plant supplies photosynthetic products to the AM fungi, which in return provide phosphate and other minerals to the host through the arbuscules. Both partners gain great advantages from this symbiotic interaction, and both regulate AM development. Our recent work revealed that gibberellic acids (GAs) are required for AM development in the legume Lotus japonicus. GA signaling interact with symbiosis signaling pathways, directing AM fungal colonization in host roots. Expression analysis showed that genes for GA biosynthesis and metabolism were induced in host roots around AM fungal hyphae, suggesting that the GA signaling changes with both location and time during AM development. The fluctuating GA concentrations sometimes positively and sometimes negatively affect the expression of AM-induced genes that regulate AM fungal infection and colonization.

  17. Matching roots to their environment.

    Science.gov (United States)

    White, Philip J; George, Timothy S; Gregory, Peter J; Bengough, A Glyn; Hallett, Paul D; McKenzie, Blair M

    2013-07-01

    Plants form the base of the terrestrial food chain and provide medicines, fuel, fibre and industrial materials to humans. Vascular land plants rely on their roots to acquire the water and mineral elements necessary for their survival in nature or their yield and nutritional quality in agriculture. Major biogeochemical fluxes of all elements occur through plant roots, and the roots of agricultural crops have a significant role to play in soil sustainability, carbon sequestration, reducing emissions of greenhouse gasses, and in preventing the eutrophication of water bodies associated with the application of mineral fertilizers. This article provides the context for a Special Issue of Annals of Botany on 'Matching Roots to Their Environment'. It first examines how land plants and their roots evolved, describes how the ecology of roots and their rhizospheres contributes to the acquisition of soil resources, and discusses the influence of plant roots on biogeochemical cycles. It then describes the role of roots in overcoming the constraints to crop production imposed by hostile or infertile soils, illustrates root phenotypes that improve the acquisition of mineral elements and water, and discusses high-throughput methods to screen for these traits in the laboratory, glasshouse and field. Finally, it considers whether knowledge of adaptations improving the acquisition of resources in natural environments can be used to develop root systems for sustainable agriculture in the future.

  18. Preliminary studies of the biosynthesis of Austin

    International Nuclear Information System (INIS)

    Wicnienski, N.A.

    1979-01-01

    Aspergillus ustus is one of the most prevalent fungi in the soil. There are now two reports of the occurrence of toxin-producing strains of this fungus on stored foodstuffs. In addition, strains of A. ustus have been isolated along with Penicillium species from samples of South African cheeses. All A. ustus isolates tested were judged to be highly toxic to ducklings when grown on maize meal, however, the toxins involved were not isolated. Austin is the trivial name of one of the toxins made by the fungus found on stored food. Preliminary work to studying the biosynthesis of this compound using 13 C-labeled sodium acetate is reported here. The feasibility of the biosynthetic study was determined by feeding [1- 14 C]-sodium acetate to A. ustus cultures. The assignments made in the 13 C-nmr spectrum of Austin are shown. The lowest dilution factor obtained in [1- 14 C]-sodium acetate feeding experiments was 14. This dilution factor is sufficiently low to allow a successful feeding of [1,2- 13 C 2 ]-sodium acetate. A new metabolite of A. ustus, deacetylaustin, was isolated and identified. An alkaloid of unknown structure was also isolated from the fungus

  19. Tyrosine biosynthesis, metabolism, and catabolism in plants.

    Science.gov (United States)

    Schenck, Craig A; Maeda, Hiroshi A

    2018-05-01

    L-Tyrosine (Tyr) is an aromatic amino acid (AAA) required for protein synthesis in all organisms, but synthesized de novo only in plants and microorganisms. In plants, Tyr also serves as a precursor of numerous specialized metabolites that have diverse physiological roles as electron carriers, antioxidants, attractants, and defense compounds. Some of these Tyr-derived plant natural products are also used in human medicine and nutrition (e.g. morphine and vitamin E). While the Tyr biosynthesis and catabolic pathways have been extensively studied in microbes and animals, respectively, those of plants have received much less attention until recently. Accumulating evidence suggest that the Tyr biosynthetic pathways differ between microbes and plants and even within the plant kingdom, likely to support the production of lineage-specific plant specialized metabolites derived from Tyr. The interspecies variations of plant Tyr pathway enzymes can now be used to enhance the production of Tyr and Tyr-derived compounds in plants and other synthetic biology platforms. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA biosynthesis

    Directory of Open Access Journals (Sweden)

    Guo-Qiang Chen

    2017-09-01

    Full Text Available Polyhydroxyalkanoates (PHA have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth of microorganisms as well as difficulty of downstream separation. Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles, developments of engineering approaches for the extremophiles, increase on carbon substrates to PHA conversion and controlling Mw of PHA. The concept proof studies could still be conducted on E. coli or Pseudomonas spp. that are easily used for molecular manipulations. In this review, we will use E. coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.

  1. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA) biosynthesis.

    Science.gov (United States)

    Chen, Guo-Qiang; Jiang, Xiao-Ran

    2017-09-01

    Polyhydroxyalkanoates (PHA) have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw) and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth of microorganisms as well as difficulty of downstream separation. Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles, developments of engineering approaches for the extremophiles, increase on carbon substrates to PHA conversion and controlling Mw of PHA. The concept proof studies could still be conducted on E. coli or Pseudomonas spp. that are easily used for molecular manipulations. In this review, we will use E. coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.

  2. Biosynthesis of myristic acid in luminescent bacteria

    International Nuclear Information System (INIS)

    Byers, D.M.

    1987-01-01

    In vivo pulse-label studies have demonstrated that luminescent bacteria can provide myritic acid (14:0) required for the synthesis of the luciferase substrate myristyl aldehyde. Luminescent wild type Vibrio harveyi incubated with [ 14 C] acetate in a nutrient-depleted medium accumulated substantial tree [ 14 C]fatty acid (up to 20% of the total lipid label). Radio-gas chromatography revealed that > 75% of the labeled fatty acid is 14:0. No free fatty acid was detected in wild type cells labeled prior to the development of bioluminescence in the exponential growth phase, or in a dark mutant of V. harveyi (mutant M17) that requires exogenous 14:0 for light emission. The preferential accumulation of 14:0 was not observed when wild type cells were labeled with [ 14 C]acetate in regular growth medium. Moreover, all V. harveyi strains exhibited similar fatty acid mass compositions regardless of the state of bioluminescence. Since earlier work has shown that a luminescence-related acyltransferase (defective in the M17 mutant) can catalyze the deacylation of fatty acyl-acyl carrier protein in vitro, the present results are consistent with a model in which this enzyme diverts 14:0 to the luminescence system during fatty acid biosynthesis. Under normal conditions, the supply of 14:0 by this pathway is tightly regulated such that bioluminescence development does not significantly alter the total fatty acid composition

  3. Control of triacylglycerol biosynthesis in plants

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-31

    Seeds of most species of the Umbelliferae (Apiaciae), Araliaceae, and Garryaceae families are characterized by their high content of the unusual C[sub 18] monounsaturated fatty acid petroselinic acid (18:l[Delta][sup 6cis]). Prior to a recent report of this lab, little was known of the biosynthetic origin of the cis[Delta][sup 6] double bond of petroselinic acid. Such knowledge may be of both biochemical and biotechnological significance. Because petroselinic acid is potentially the product of a novel desaturase, information regarding its synthesis may contribute to an understanding of fatty acid desaturation mechanisms in plants. Through chemical cleavage at its double bond, petroselinic acid can be used as a precursor of lauric acid (12:0), a component of detergents and surfactants, and adipic acid (6:0 dicarboxylic), the monomeric component of nylon 6,6. Therefore, the development of an agronomic source of an oil rich in petroselinic acid is of biotechnological interest. As such, studies of petroselinic acid biosynthesis may provide basic information required for any attempt to genetically engineer the production and accumulation of this fatty acid in an existing oilseed.

  4. 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

  5. The regulation and biosynthesis of antimycins

    Directory of Open Access Journals (Sweden)

    Ryan F. Seipke

    2013-11-01

    Full Text Available Antimycins (>40 members were discovered nearly 65 years ago but the discovery of the gene cluster encoding antimycin biosynthesis in 2011 has facilitated rapid progress in understanding the unusual biosynthetic pathway. Antimycin A is widely used as a piscicide in the catfish farming industry and also has potent killing activity against insects, nematodes and fungi. The mode of action of antimycins is to inhibit cytochrome c reductase in the electron transport chain and halt respiration. However, more recently, antimycin A has attracted attention as a potent and selective inhibitor of the mitochondrial anti-apoptotic proteins Bcl-2 and Bcl-xL. Remarkably, this inhibition is independent of the main mode of action of antimycins such that an artificial derivative named 2-methoxyantimycin A inhibits Bcl-xL but does not inhibit respiration. The Bcl-2/Bcl-xL family of proteins are over-produced in cancer cells that are resistant to apoptosis-inducing chemotherapy agents, so antimycins have great potential as anticancer drugs used in combination with existing chemotherapeutics. Here we review what is known about antimycins, the regulation of the ant gene cluster and the unusual biosynthetic pathway.

  6. Estrogen biosynthesis in human uterine adenomyosis

    International Nuclear Information System (INIS)

    Urabe, Mamoru; Yamamoto, Takara; Kitawaki, Jo; Honjo, Hideo; Okada, Hiroji

    1989-01-01

    Estrogen biosynthesis (aromatiase activity) was investigated in human adenomyosis tissue and compared with that of the normal myometrium, endometrium, and endometrical cancer tissues. Homogenates were incubated with [1,2,6,7- 3 H]androstenedione and NADPH at 37 deg. C for 1 h. After stopping the enzymatic reaction with ethyl acetate, [4- 14 C]estrone and [4- 14 C]estradiol-17β were added to the incubated sample. Estrone and estradiol were purified and identified by Bio-Rad AG1-X2 column chromatography, thin-layer chromatography and co-crystallization. Estrogen formed in the incubated sample was calculated from the 3 H/ 14 C ratio of the final crystal. The value for estrone formed from androstenedione was 52-132 fmol . h -1. g -1 wet weight. Aromatase activity in the adenomyosis tissues was higher than that in normal endometrial or myometrial tissues, but lower than that found in myometrial or endometrial tumour tissue. Furthermore, we investigated the effect of danazol, progresterone, and medroxyprogesterone acetate on adenomyosis cells in primary cultures. Aromatase activity in adenomyosis was blocked by danazol, but stimulated by progesterone and MPA. These results indicate that aromatase activity in adenomyosis may contribute to the growth of the ectopic endometrial tissue which occurs in this disease. (author)

  7. Glycoprotein biosynthesis by human normal platelets

    International Nuclear Information System (INIS)

    Rodriguez, P.; Bello, O.; Apitz-Castro, R.

    1987-01-01

    Incorporation of radioactive Man, Gal, Fuc, Glc-N, and NANA into washed human normal platelets and endogenous glycoproteins has been found. Both parameters were time dependent. Analysis of hydrolyzed labeled glycoproteins by paper chromatography revealed that the radioactive monosaccharide incubated with the platelets had not been converted into other sugars. Acid hydrolysis demonstrates the presence of a glycosidic linkage. All the effort directed to the demonstration of the existence of a lipid-sugar intermediate in intact human platelets yielded negative results for Man and Glc-N used as precursors. The incorporation of these sugars into glycoproteins is insensitive to bacitracin, suggesting no involvement of lipid-linked saccharides in the synthesis of glycoproteins in human blood platelets. The absence of inhibition of the glycosylation process in the presence of cycloheximide suggests that the sugars are added to proteins present in the intact platelets. These results support the contention that glycoprotein biosynthesis in human blood platelets observed under our experimental conditions is effected through direct sugar nucleotide glycosylation

  8. Biosynthesis and metabolism of steroids in molluscs.

    Science.gov (United States)

    Fernandes, Denise; Loi, Barbara; Porte, Cinta

    2011-11-01

    Molluscs are the second most diverse animal group, they are ecologically important and they are considered excellent indicators of ecosystem health. Some species have been widely used in pollution biomonitoring programs; however, their endocrinology is still poorly known. Despite some studies reporting the presence of (vertebrate-type) steroids in molluscs, information regarding enzymatic pathways involved in steroid synthesis and further catabolism of those steroids is still fragmentary. Regarding steroidogenesis, a number of excellent studies were performed in the 70s using different radio-labelled steroid precursors and detecting the formation of different metabolites. But, since then a long gap of research exist until the late 90s when the 'endocrine disruption' issue raised the need of a better knowledge of mollusc (and invertebrate) endocrinology in order to assess alterations caused by pollutants. Here we summarize past and recent studies dealing with steroid biosynthesis and metabolism in different mollusc species. Most of these studies suggest the involvement of steroids in mollusc reproduction. However, the knowledge is still fragmentary and many questions remain to be answered. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Transcriptional analysis of apple fruit proanthocyanidin biosynthesis

    Science.gov (United States)

    Henry-Kirk, Rebecca A.

    2012-01-01

    Proanthocyanidins (PAs) are products of the flavonoid pathway, which also leads to the production of anthocyanins and flavonols. Many flavonoids have antioxidant properties and may have beneficial effects for human health. PAs are found in the seeds and fruits of many plants. In apple fruit (Malus × domestica Borkh.), the flavonoid biosynthetic pathway is most active in the skin, with the flavan-3-ols, catechin, and epicatechin acting as the initiating units for the synthesis of PA polymers. This study examined the genes involved in the production of PAs in three apple cultivars: two heritage apple cultivars, Hetlina and Devonshire Quarrenden, and a commercial cultivar, Royal Gala. HPLC analysis shows that tree-ripe fruit from Hetlina and Devonshire Quarrenden had a higher phenolic content than Royal Gala. Epicatechin and catechin biosynthesis is under the control of the biosynthetic enzymes anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR1), respectively. Counter-intuitively, real-time quantitative PCR analysis showed that the expression levels of Royal Gala LAR1 and ANR were significantly higher than those of both Devonshire Quarrenden and Hetlina. This suggests that a compensatory feedback mechanism may be active, whereby low concentrations of PAs may induce higher expression of gene transcripts. Further investigation is required into the regulation of these key enzymes in apple. Abbreviations:ANOVAanalysis of varianceANRanthocyanidin reductaseDADdiode array detectorDAFBdays after full bloomDFRdihydroflavonol reductaseLARleucoanthocyanidin reductaseLC-MSliquid chromatography/mass spectrometryPAproanthocyanidinqPCRreal-time quantitative PCR PMID:22859681

  10. Explorations into the biosynthesis of bioscorine

    Energy Technology Data Exchange (ETDEWEB)

    Michelson, R.H.

    1988-01-01

    The biosynthesis of dioscorine in Dioscorea hispida has been studied by the feeding of putative precursors labelled at specific positions with {sup 2}H, {sup 3}H, and {sup 14}C. Administration of (3-{sup 14}C)3-hydroxy-3-methylglutaric acid to D. hispida by the wick method afforded dioscorine labelled preferentially at the C{sub 10} position implying that the biosynthetic pathway to the acetate-derived half of the dioscorine skeleton is going through this compound. Administration of ethyl (6-{sup 14}C)orsellinate to D. hispida by the wick method failed to give an appreciable incorporation into dioscroine thereby disproving an alternative mechanism describing the formation of the acetate-derived half of the dioscorine skeleton. Two attempts to simulate the alternative mechanism by oxidatively cleaving ethyl orsellinate also failed, further disfavoring this mechanism. Administration of (2,3){sup 13}C{sub 2}, {sup 14}C{sub 2}succinic acid, (3-{sup 14}C)aspartic acid and (7a-{sup 14}C)tryptophan by the leaf painting method gave very low incorporations into dioscorine making determination of the source of the nicotinic acid half of the dioscorine skeleton inconclusive. Administration of (6-{sup 2}H, {sup 3}H)nicotinic acid to D. hispida by the wick method afforded dioscorine exhibiting complete retention of {sup 3}H thereby disfavoring a mechanism involving a 3,6-dihydropyridine intermediate in the formation of the dioscorine skeleton.

  11. Identification of a Second Site of Pyrrolizidine Alkaloid Biosynthesis in Comfrey to Boost Plant Defense in Floral Stage1,2[OPEN

    Science.gov (United States)

    Stegemann, Thomas; Sievert, Christian

    2017-01-01

    Pyrrolizidine alkaloids (PAs) are toxic secondary metabolites that are found in several distantly related families of the angiosperms. The first specific step in PA biosynthesis is catalyzed by homospermidine synthase (HSS), which has been recruited several times independently by duplication of the gene encoding deoxyhypusine synthase, an enzyme involved in the posttranslational activation of the eukaryotic initiation factor 5A. HSS shows highly diverse spatiotemporal gene expression in various PA-producing species. In comfrey (Symphytum officinale; Boraginaceae), PAs are reported to be synthesized in the roots, with HSS being localized in cells of the root endodermis. Here, we show that comfrey plants activate a second site of HSS expression when inflorescences start to develop. HSS has been localized in the bundle sheath cells of specific leaves. Tracer feeding experiments have confirmed that these young leaves express not only HSS but the whole PA biosynthetic route. This second site of PA biosynthesis results in drastically increased PA levels within the inflorescences. The boost of PA biosynthesis is proposed to guarantee optimal protection especially of the reproductive structures. PMID:28275146

  12. Isolation of biosynthesis related transcripts of 2,3,5,4'-tetrahydroxy stilbene-2-O-β-D-glucoside from Fallopia multiflora by suppression subtractive hybridization

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    2014-07-01

    Full Text Available 2,3,5,4'-tetrahydroxy stilbene-2-O-ß-D-glucoside (THSG exerts multiple pharmacodynamic actions, found in Fallopia multiflora, but the biosynthesis pathway of THSG is still unclear. To clear this ambiguity, we constructed suppression subtractive hybridization (SSH libraries to screen the genes involved in THSG biosynthesis from two F. multiflora varieties, which vary significantly in THSG content. Twelve non-redundant differentially expressed sequence tags were obtained and the full lengths of 4 unreported fragments were amplified by rapid amplification of cDNA ends. We totally got 7 full-length transcripts, and all of them were aligned to the transcriptome and digital gene expression tag profiling database of four F. multiflora tissues (root, stem and leaf from Deqing F. multiflora and another root from Chongqing F. multiflora; data unpublished using local BLAST. The results showed that there was a significant, organ specific difference in the expression of fragments and full-length sequences. All the sequences were annotated by aligning to nucleotide and protein databases. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that THSG biosynthesis was correlated with multiple life activities.

  13. De Novo RNA Sequencing and Expression Analysis of Aconitum carmichaelii to Analyze Key Genes Involved in the Biosynthesis of Diterpene Alkaloids

    Directory of Open Access Journals (Sweden)

    Megha Rai

    2017-12-01

    Full Text Available Aconitum carmichaelii is an important medicinal herb used widely in China, Japan, India, Korea, and other Asian countries. While extensive research on the characterization of metabolic extracts of A. carmichaelii has shown accumulation of numerous bioactive metabolites including aconitine and aconitine-type diterpene alkaloids, its biosynthetic pathway remains largely unknown. Biosynthesis of these secondary metabolites is tightly controlled and mostly occurs in a tissue-specific manner; therefore, transcriptome analysis across multiple tissues is an attractive method to identify the molecular components involved for further functional characterization. In order to understand the biosynthesis of secondary metabolites, Illumina-based deep transcriptome profiling and analysis was performed for four tissues (flower, bud, leaf, and root of A. carmichaelii, resulting in 5.5 Gbps clean RNA-seq reads assembled into 128,183 unigenes. Unigenes annotated as possible rate-determining steps of an aconitine-type biosynthetic pathway were highly expressed in the root, in accordance with previous reports describing the root as the accumulation site for these metabolites. We also identified 21 unigenes annotated as cytochrome P450s and highly expressed in roots, which represent candidate unigenes involved in the diversification of secondary metabolites. Comparative transcriptome analysis of A. carmichaelii with A. heterophyllum identified 20,232 orthogroups, representing 30,633 unigenes of A. carmichaelii, gene ontology enrichment analysis of which revealed essential biological process together with a secondary metabolic process to be highly enriched. Unigenes identified in this study are strong candidates for aconitine-type diterpene alkaloid biosynthesis, and will serve as useful resources for further validation studies.

  14. RootJS : Node.js Bindings for ROOT 6

    OpenAIRE

    Beffart, Theo; Früh, Maximilian; Haas, Christoph; Rajgopal, Sachin; Schwabe, Jonas; Wolff, Christoph; Szuba, Marek

    2017-01-01

    We present rootJS, an interface making it possible to seamlessly integrate ROOT 6 into applications written for Node.js, the JavaScript runtime platform increasingly commonly used to create high-performance Web applications. ROOT features can be called both directly from Node.js code and by JIT-compiling C++ macros. All rootJS methods are invoked asynchronously and support callback functions, allowing non-blocking operation of Node.js applications using them. Last but not least, our bindings ...

  15. Expression of Root Genes in Arabidopsis Seedlings Grown by Standard and Improved Growing Methods

    Directory of Open Access Journals (Sweden)

    Yanli Qu

    2017-05-01

    Full Text Available Roots of Arabidopsis thaliana seedlings grown in the laboratory using the traditional plant-growing culture system (TPG were covered to maintain them in darkness. This new method is based on a dark chamber and is named the improved plant-growing method (IPG. We measured the light conditions in dark chambers, and found that the highest light intensity was dramatically reduced deeper in the dark chamber. In the bottom and side parts of dark chambers, roots were almost completely shaded. Using the high-throughput RNA sequencing method on the whole RNA extraction from roots, we compared the global gene expression levels in roots of seedlings from these two conditions and identified 141 differently expressed genes (DEGs between them. According to the KEGG (Kyoto Encyclopedia of Genes and Genomes enrichment, the flavone and flavonol biosynthesis and flavonoid biosynthesis pathways were most affected among all annotated pathways. Surprisingly, no genes of known plant photoreceptors were identified as DEGs by this method. Considering that the light intensity was decreased in the IPG system, we collected four sections (1.5 cm for each of Arabidopsis roots grown in TPG and IPG conditions, and the spatial-related differential gene expression levels of plant photoreceptors and polar auxin transporters, including CRY1, CRY2, PHYA, PHYB, PHOT1, PHOT2, and UVR8 were analyzed by qRT-PCR. Using these results, we generated a map of the spatial-related expression patterns of these genes under IPG and TPG conditions. The expression levels of light-related genes in roots is highly sensitive to illumination and it provides a background reference for selecting an improved culture method for laboratory-maintained Arabidopsis seedlings.

  16. Expression of Root Genes in Arabidopsis Seedlings Grown by Standard and Improved Growing Methods.

    Science.gov (United States)

    Qu, Yanli; Liu, Shuai; Bao, Wenlong; Xue, Xian; Ma, Zhengwen; Yokawa, Ken; Baluška, František; Wan, Yinglang

    2017-05-03

    Roots of Arabidopsis thaliana seedlings grown in the laboratory using the traditional plant-growing culture system (TPG) were covered to maintain them in darkness. This new method is based on a dark chamber and is named the improved plant-growing method (IPG). We measured the light conditions in dark chambers, and found that the highest light intensity was dramatically reduced deeper in the dark chamber. In the bottom and side parts of dark chambers, roots were almost completely shaded. Using the high-throughput RNA sequencing method on the whole RNA extraction from roots, we compared the global gene expression levels in roots of seedlings from these two conditions and identified 141 differently expressed genes (DEGs) between them. According to the KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment, the flavone and flavonol biosynthesis and flavonoid biosynthesis pathways were most affected among all annotated pathways. Surprisingly, no genes of known plant photoreceptors were identified as DEGs by this method. Considering that the light intensity was decreased in the IPG system, we collected four sections (1.5 cm for each) of Arabidopsis roots grown in TPG and IPG conditions, and the spatial-related differential gene expression levels of plant photoreceptors and polar auxin transporters, including CRY1 , CRY2 , PHYA , PHYB , PHOT1 , PHOT2 , and UVR8 were analyzed by qRT-PCR. Using these results, we generated a map of the spatial-related expression patterns of these genes under IPG and TPG conditions. The expression levels of light-related genes in roots is highly sensitive to illumination and it provides a background reference for selecting an improved culture method for laboratory-maintained Arabidopsis seedlings.

  17. Nicotinamidase participates in the salvage pathway of NAD biosynthesis in Arabidopsis.

    Science.gov (United States)

    Wang, Guodong; Pichersky, Eran

    2007-03-01

    Nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which is derived from NAD, have important roles as a redox carriers in metabolism. A combination of de novo and salvage pathways contribute to the biosynthesis of NAD in all organisms. The pathways and enzymes of the NAD salvage pathway in yeast and animals, which diverge at nicotinamide, have been extensively studied. Yeast cells convert nicotinamide to nicotinic acid, while mammals lack the enzyme nicotinamidase and instead convert nicotinamide to nicotinamide mononucleotide. Here we show that Arabidopsis thaliana gene At2g22570 encodes a nicotinamidase, which is expressed in all tissues, with the highest levels observed in roots and stems. The 244-residue protein, designated AtNIC1, converts nicotinamide to nicotinic acid and has a Km value of 118 +/- 17 microM and a Kcat value of 0.93 +/- 0.13 sec(-1). Plants homozygous for a null AtNIC1 allele, nic1-1, have lower levels of NAD and NADP under normal growth conditions, indicating that AtNIC1 participates in a yeast-type NAD salvage pathway. Mutant plants also exhibit hypersensitivity to treatments of abscisic acid and NaCl, which is correlated with their inability to increase the cellular levels of NAD(H) under these growth conditions, as occurs in wild-type plants. We also show that the growth of the roots of wild-type but not nic1-1 mutant plants is inhibited and distorted by nicotinamide.

  18. Cytomorphologic features distinguishing Bethesda category IV thyroid lesions from parathyroid

    Directory of Open Access Journals (Sweden)

    Simon Sung

    2017-01-01

    Full Text Available Background: Thyroid follicular cells share similar cytomorphological features with parathyroid. Without a clinical suspicion, the distinction between a thyroid neoplasm and an intrathyroidal parathyroid can be challenging. The aim of this study was to assess the distinguishing cytomorphological features of parathyroid (including intrathyroidal and Bethesda category IV (Beth-IV thyroid follicular lesions, which carry a 15%–30% risk of malignancy and are often followed up with surgical resection. Methods: A search was performed to identify “parathyroid” diagnoses in parathyroid/thyroid-designated fine-needle aspirations (FNAs and Beth-IV thyroid FNAs (follicular and Hurthle cell, all with diagnostic confirmation through surgical pathology, immunocytochemical stains, Afirma® analysis, and/or clinical correlation. Unique cytomorphologic features were scored (0-3 or noted as present versus absent. Statistical analysis was performed using R 3.3.1 software. Results: We identified five FNA cases with clinical suspicion of parathyroid neoplasm, hyperthyroidism, or thyroid lesion that had an eventual final diagnosis of the parathyroid lesion (all female; age 20–69 years and 12 Beth-IV diagnoses (11 female, 1 male; age 13–64 years. The following cytomorphologic features are useful distinguishing features (P value: overall pattern (0.001, single cells (0.001, cell size compared to red blood cell (0.01, nuclear irregularity (0.001, presence of nucleoli (0.001, nuclear-to-cytoplasmic ratio (0.007, and nuclear chromatin quality (0.028. Conclusions: There are cytomorphologic features that distinguish Beth-IV thyroid lesions and (intrathyroidal parathyroid. These features can aid in rendering correct diagnoses and appropriate management.

  19. ROOT Tutorial for Summer Students

    CERN Multimedia

    CERN. Geneva; Piparo, Danilo

    2015-01-01

    ROOT is a "batteries-included" tool kit for data analysis, storage and visualization. It is widely used in High Energy Physics and other disciplines such as Biology, Finance and Astrophysics. This event is an introductory tutorial to ROOT and comprises a front lecture and hands on exercises. IMPORTANT NOTE: The tutorial is based on ROOT 6.04 and NOT on the ROOT5 series.  IMPORTANT NOTE: if you have ROOT 6.04 installed on your laptop, you will not need to install any virtual machine. The instructions showing how to install the virtual machine on which you can find ROOT 6.04 can be found under "Material" on this page.

  20. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  1. Genetic profiles distinguish different types of hereditary ovarian cancer

    DEFF Research Database (Denmark)

    Domanska, Katarina; Malander, Susanne; Staaf, Johan

    2010-01-01

    Heredity represents the strongest risk factor for ovarian cancer with disease predisposing mutations identified in 15% of the tumors. With the aim to identify genetic classifiers for hereditary ovarian cancer, we profiled hereditary ovarian cancers linked to the hereditary breast and ovarian cancer...... as a control group. Unsupervised cluster analysis identified two distinct subgroups related to genetic complexity. Sporadic and HBOC associated tumors had complex genetic profiles with an average 41% of the genome altered, whereas the mismatch repair defective tumors had stable genetic profiles...... that HBOC and HNPCC associated ovarian cancer develop along distinct genetic pathways and genetic profiles can thus be applied to distinguish between different types of hereditary ovarian cancer....

  2. How bees distinguish patterns by green and blue modulation

    Directory of Open Access Journals (Sweden)

    Horridge A

    2015-10-01

    Full Text Available Adrian Horridge Biological Sciences, Australian National University, Canberra, ACT, Australia Abstract: In the 1920s, Mathilde Hertz found that trained bees discriminated between shapes or patterns of similar size by something related to total length of contrasting contours. This input is now interpreted as modulation in green and blue receptor channels as flying bees scan in the horizontal plane. Modulation is defined as total contrast irrespective of sign multiplied by length of edge displaying that contrast, projected to vertical, therefore, combining structure and contrast in a single input. Contrast is outside the eye; modulation is a phasic response in receptor pathways inside. In recent experiments, bees trained to distinguish color detected, located, and measured three independent inputs and the angles between them. They are the tonic response of the blue receptor pathway and modulation of small-field green or (less preferred blue receptor pathways. Green and blue channels interacted intimately at a peripheral level. This study explores in more detail how various patterns are discriminated by these cues. The direction of contrast at a boundary was not detected. Instead, bees located and measured total modulation generated by horizontal scanning of contrasts, irrespective of pattern. They also located the positions of isolated vertical edges relative to other landmarks and distinguished the angular widths between vertical edges by green or blue modulation alone. The preferred inputs were the strongest green modulation signal and angular width between outside edges, irrespective of color. In the absence of green modulation, the remaining cue was a measure and location of blue modulation at edges. In the presence of green modulation, blue modulation was inhibited. Black/white patterns were distinguished by the same inputs in blue and green receptor channels. Left–right polarity and mirror images could be discriminated by retinotopic green

  3. How to distinguish dark energy and modified gravity?

    International Nuclear Information System (INIS)

    Wei Hao; Zhang Shuangnan

    2008-01-01

    The current accelerated expansion of our universe could be due to an unknown energy component (dark energy) or a modification of general relativity (modified gravity). In the literature it has been proposed that combining the probes of the cosmic expansion history and growth history can distinguish between dark energy and modified gravity. In this work, without invoking nontrivial dark energy clustering, we show that the possible interaction between dark energy and dark matter could make the interacting dark model and the modified gravity model indistinguishable. An explicit example is also given. Therefore, it is required to seek some complementary probes beyond the ones of cosmic expansion history and growth history.

  4. How bees distinguish patterns by green and blue modulation.

    Science.gov (United States)

    Horridge, Adrian

    2015-01-01

    In the 1920s, Mathilde Hertz found that trained bees discriminated between shapes or patterns of similar size by something related to total length of contrasting contours. This input is now interpreted as modulation in green and blue receptor channels as flying bees scan in the horizontal plane. Modulation is defined as total contrast irrespective of sign multiplied by length of edge displaying that contrast, projected to vertical, therefore, combining structure and contrast in a single input. Contrast is outside the eye; modulation is a phasic response in receptor pathways inside. In recent experiments, bees trained to distinguish color detected, located, and measured three independent inputs and the angles between them. They are the tonic response of the blue receptor pathway and modulation of small-field green or (less preferred) blue receptor pathways. Green and blue channels interacted intimately at a peripheral level. This study explores in more detail how various patterns are discriminated by these cues. The direction of contrast at a boundary was not detected. Instead, bees located and measured total modulation generated by horizontal scanning of contrasts, irrespective of pattern. They also located the positions of isolated vertical edges relative to other landmarks and distinguished the angular widths between vertical edges by green or blue modulation alone. The preferred inputs were the strongest green modulation signal and angular width between outside edges, irrespective of color. In the absence of green modulation, the remaining cue was a measure and location of blue modulation at edges. In the presence of green modulation, blue modulation was inhibited. Black/white patterns were distinguished by the same inputs in blue and green receptor channels. Left-right polarity and mirror images could be discriminated by retinotopic green modulation alone. Colors in areas bounded by strong green contrast were distinguished as more or less blue than the

  5. Antiplasmodial dimeric chalcone derivatives from the roots of Uvaria siamensis.

    Science.gov (United States)

    Salae, Abdul-Wahab; Chairerk, Orapan; Sukkoet, Piyanut; Chairat, Therdsak; Prawat, Uma; Tuntiwachwuttikul, Pittaya; Chalermglin, Piya; Ruchirawat, Somsak

    2017-03-01

    Four dimeric chalcone derivatives, 8″,9″-dihydrowelwitschin H, uvarins A-C, a naphthalene derivative, 2-hydroxy-3-methoxy-6-(4'- hydroxyphenyl)naphthalene, and the known dimeric chalcones, dependensin and welwitschin E, flavonoids, a cyclohexane oxide derivative, an aromatic aldehyde were isolated from the roots of Uvaria siamensis (Annonaceae). The structures of the compounds were elucidated by spectroscopic analysis, as well as by comparison with literature data. The isolated compounds with a sufficient amount for biological assays were evaluated for their antimalarial, antimycobacterial, and cytotoxic activities. The dimeric chalcones 8″,9″-dihydrowelwitschin H, uvarins B and C, dependensin and welwitschin E showed strong antiplasmodial activity with IC 50 values of 3.10, 3.02, 3.09, 4.21 and 3.99 μg/mL, respectively. A possible biosynthesis pathway of the dimeric chalcones is discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Comparing Leaf and Root Insertion

    Directory of Open Access Journals (Sweden)

    Jaco Geldenhuys

    2010-07-01

    Full Text Available We consider two ways of inserting a key into a binary search tree: leaf insertion which is the standard method, and root insertion which involves additional rotations. Although the respective cost of constructing leaf and root insertion binary search trees trees, in terms of comparisons, are the same in the average case, we show that in the worst case the construction of a root insertion binary search tree needs approximately 50% of the number of comparisons required by leaf insertion.

  7. Root communication among desert shrubs.

    OpenAIRE

    Mahall, B E; Callaway, R M

    1991-01-01

    Descriptive and experimental studies of desert shrub distributions have revealed important questions about the mechanisms by which plants interact. For example, do roots interact by mechanisms other than simple competition for limiting resources? We investigated this question using the desert shrubs Ambrosia dumosa and Larrea tridentata grown in chambers that allowed observation of roots during intraplant and intra- and interspecific interplant encounters. Two types of root "communication" we...

  8. Facilitative root interactions in intercrops

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Jensen, E.S.

    2005-01-01

    Facilitation takes place when plants ameliorate the environment of their neighbours, and increase their growth and survival. Facilitation occurs in natural ecosystems as well as in agroecosystems. We discuss examples of facilitative root interactions in intercropped agroecosystems; including...... of root architecture, exudation of growth stimulating substances, and biofumigation. Facilitative root interactions are most likely to be of importance in nutrient poor soils and in low-input agroecosystems due to critical interspecific competition for plant growth factors. However, studies from more...

  9. Proteomics of Maize Root Development.

    Science.gov (United States)

    Hochholdinger, Frank; Marcon, Caroline; Baldauf, Jutta A; Yu, Peng; Frey, Felix P

    2018-01-01

    Maize forms a complex root system with structurally and functionally diverse root types that are formed at different developmental stages to extract water and mineral nutrients from soil. In recent years proteomics has been intensively applied to identify proteins involved in shaping the three-dimensional architecture and regulating the function of the maize root system. With the help of developmental mutants, proteomic changes during the initiation and emergence of shoot-borne, lateral and seminal roots have been examined. Furthermore, root hairs were surveyed to understand the proteomic changes during the elongation of these single cell type structures. In addition, primary roots have been used to study developmental changes of the proteome but also to investigate the proteomes of distinct tissues such as the meristematic zone, the elongation zone as well as stele and cortex of the differentiation zone. Moreover, subcellular fractions of the primary root including cell walls, plasma membranes and secreted mucilage have been analyzed. Finally, the superior vigor of hybrid seedling roots compared to their parental inbred lines was studied on the proteome level. In summary, these studies provide novel insights into the complex proteomic interactions of the elaborate maize root system during development.

  10. Proteomics of Maize Root Development

    Directory of Open Access Journals (Sweden)

    Frank Hochholdinger

    2018-03-01

    Full Text Available Maize forms a complex root system with structurally and functionally diverse root types that are formed at different developmental stages to extract water and mineral nutrients from soil. In recent years proteomics has been intensively applied to identify proteins involved in shaping the three-dimensional architecture and regulating the function of the maize root system. With the help of developmental mutants, proteomic changes during the initiation and emergence of shoot-borne, lateral and seminal roots have been examined. Furthermore, root hairs were surveyed to understand the proteomic changes during the elongation of these single cell type structures. In addition, primary roots have been used to study developmental changes of the proteome but also to investigate the proteomes of distinct tissues such as the meristematic zone, the elongation zone as well as stele and cortex of the differentiation zone. Moreover, subcellular fractions of the primary root including cell walls, plasma membranes and secreted mucilage have been analyzed. Finally, the superior vigor of hybrid seedling roots compared to their parental inbred lines was studied on the proteome level. In summary, these studies provide novel insights into the complex proteomic interactions of the elaborate maize root system during development.

  11. Properties of Estimated Characteristic Roots

    DEFF Research Database (Denmark)

    Nielsen, Bent; Nielsen, Heino Bohn

    Estimated characteristic roots in stationary autoregressions are shown to give rather noisy information about their population equivalents. This is remarkable given the central role of the characteristic roots in the theory of autoregressive processes. In the asymptotic analysis the problems appear...... when multiple roots are present as this imply a non-differentiability so the d-method does not apply, convergence rates are slow, and the asymptotic distribution is non-normal. In finite samples this has a considerable influence on the finite sample distribution unless the roots are far apart...

  12. GENETIC ANALYSIS OF ABSCISIC ACID BIOSYNTHESIS

    Energy Technology Data Exchange (ETDEWEB)

    MCCARTY D R

    2012-01-10

    The carotenoid cleavage dioxygenases (CCD) catalyze synthesis of a variety of apo-carotenoid secondary metabolites in plants, animals and bacteria. In plants, the reaction catalyzed by the 11, 12, 9-cis-epoxy carotenoid dioxygenase (NCED) is the first committed and key regulated step in synthesis of the plant hormone, abscisic acid (ABA). ABA is a key regulator of plant stress responses and has critical functions in normal root and seed development. The molecular mechanisms responsible for developmental control of ABA synthesis in plant tissues are poorly understood. Five of the nine CCD genes present in the Arabidopsis genome encode NCED's involved in control of ABA synthesis in the plant. This project is focused on functional analysis of these five AtNCED genes as a key to understanding developmental regulation of ABA synthesis and dissecting the role of ABA in plant development. For this purpose, the project developed a comprehensive set of gene knockouts in the AtNCED genes that facilitate genetic dissection of ABA synthesis. These mutants were used in combination with key molecular tools to address the following specific objectives: (1) the role of ABA synthesis in root development; (2) developmental control of ABA synthesis in seeds; (3) analysis of ATNCED over-expressers; (4) preliminary crystallography of the maize VP14 protein.

  13. [Effects of elicitors on growth of adventitious roots and contents of secondary metabolites in Tripterygium wilfordii Hook. f].

    Science.gov (United States)

    Li, Yan; Zhao, Lei; Cui, Lei; Lei, Jiamin; Zhang, Xing

    2015-05-01

    To study the effects of the extract of fungal elicitor, AgNO3, MeJA and yeast on the growth and content of secondary metabolites of adventitious roots in Tripterygium wilfordii. The above elicitors were supplemented to the medium, the growth and the content of secondary metabolites were measured. When the medium was supplemented with the elicitor Glomerella cingulata or Collectotrichum gloeosporioides, the content of triptolide was increased by 2.24 and 1.93-fold, the alkaloids content was increased by 2.02 and 2.07-fold, respectively. The optimal concentration of G. cingulata was 50 μg/mL for accumulation of triptolide, alkaloids and for the growth of adventitious roots. AgNO3 inhibited the growth of adventitious roots and the accumulation of the alkaloids, whereas it (at 25 μmol/L) increased the accumulation of triptolide by 1.71-fold compared to the control. The growth of adventitious roots, the contents of triptolide and alkaloids were increased 1.04, 1.64 and 2.12-folds, respectively when MeJA was at 50 μmol/L. When the concentration of yeast reached 2 g/L, the content of triptolide increased 1.48-folds. This research demonstrated that supplementation of AgNO3 and yeast enhanced the biosynthesis of triptolide in adventitious roots and the synergism of G. cingulata and MeJA could promote the biosynthesis of both triptolide and alkaloids.

  14. Differentially expressed transcripts from leaf and root tissue of Chlorophytum borivilianum: a plant with high medicinal value.

    Science.gov (United States)

    Kumar, Sunil; Kalra, Shikha; Kumar, Sanjay; Kaur, Jagdeep; Singh, Kashmir

    2012-12-10

    Chlorophytum borivilianum is one of the important medicinal plants used for treating different health problems such as diabetes, arthritis, physical weakness, etc. Saponins present in C. borivilianum are the primary source of its significant medicinal properties and are synthesized by mevalonate and non-mevalonate pathways in plants. However, the biosynthesis of these compounds at molecular level is not studied in C. borivilianum. Cloning and sequencing of genes involved in metabolic processes are prerequisite to study the gene expression, their regulation and genetic engineering experiments. Expressed sequence tags (ESTs) provide a quick insight into various genes and their tissue specific expression. Suppression subtractive hybridization (SSH) libraries were constructed using mRNA from leaf and root tissues of C. borivilianum. High quality non-redundant 506 and 303 ESTs were generated from leaf and root specific libraries respectively. These sequences were analyzed using bioinformatics tools and grouped into different categories based on their similarity and cellular functions such as photosynthesis, metabolism, transcription factors, cell signaling, defense, stress response etc. ESTs also showed similarity with genes involved in saponins biosynthesis such as squalene synthase, squalene epoxidase, cytochrome p450, glycosyltransferase, etc. Semi-quantitative analysis of some of the ESTs involved in saponins biosynthesis confirmed their differential regulation in leaves and roots. These ESTs will provide an efficient resource to accelerate gene discovery in C. borivilianum and will help in determining promising targets for genetic engineering of saponins pathway. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Yeast Extract Stimulates Ginsenoside Production in Hairy Root Cultures of American Ginseng Cultivated in Shake Flasks and Nutrient Sprinkle Bioreactors.

    Science.gov (United States)

    Kochan, Ewa; Szymczyk, Piotr; Kuźma, Łukasz; Lipert, Anna; Szymańska, Grażyna

    2017-05-26

    One of the most effective strategies to enhance metabolite biosynthesis and accumulation in biotechnological systems is the use of elicitation processes. This study assesses the influence of different concentrations of yeast extract (YE) on ginsenoside biosynthesis in Panax quinquefolium (American ginseng) hairy roots cultivated in shake flasks and in a nutrient sprinkle bioreactor after 3 and 7 days of elicitation. The saponin content was determined using HPLC. The maximum yield (20 mg g -1 d.w.) of the sum of six examined ginsenosides (Rb1, Rb2, Rc, Rd, Re and Rg1) in hairy roots cultivated in shake flasks was achieved after application of YE at 50 mg L -1 concentration and 3 day exposure time. The ginsenoside level was 1.57 times higher than that attained in control medium. The same conditions of elicitation (3 day time of exposure and 50 mg L -1 of YE) also favourably influenced the biosynthesis of studied saponins in bioreactor cultures. The total ginsenoside content was 32.25 mg g -1 d.w. and was higher than that achieved in control medium and in shake flasks cultures. Obtained results indicated that yeast extract can be used to increase ginsenoside production in hairy root cultures of P. quinquefolium .

  16. Dithiolopyrrolone Natural Products: Isolation, Synthesis and Biosynthesis

    Science.gov (United States)

    Qin, Zhiwei; Huang, Sheng; Yu, Yi; Deng, Hai

    2013-01-01

    Dithiolopyrrolones are a class of antibiotics that possess the unique pyrrolinonodithiole (4H-[1,2] dithiolo [4,3-b] pyrrol-5-one) skeleton linked to two variable acyl groups. To date, there are approximately 30 naturally occurring dithiolopyrrolone compounds, including holomycin, thiolutin, and aureothricin, and more recently thiomarinols, a unique class of hybrid marine bacterial natural products containing a dithiolopyrrolone framework linked by an amide bridge with an 8-hydroxyoctanoyl chain linked to a monic acid. Generally, dithiolopyrrolone antibiotics have broad-spectrum antibacterial activity against various microorganisms, including Gram-positive and Gram-negative bacteria, and even parasites. Holomycin appeared to be active against rifamycin-resistant bacteria and also inhibit the growth of the clinical pathogen methicillin-resistant Staphylococcus aureus N315. Its mode of action is believed to inhibit RNA synthesis although the exact mechanism has yet to be established in vitro. A recent work demonstrated that the fish pathogen Yersinia ruckeri employs an RNA methyltransferase for self-resistance during the holomycin production. Moreover, some dithiolopyrrolone derivatives have demonstrated promising antitumor activities. The biosynthetic gene clusters of holomycin have recently been identified in S. clavuligerus and characterized biochemically and genetically. The biosynthetic gene cluster of thiomarinol was also identified from the marine bacterium Pseudoalteromonas sp. SANK 73390, which was uniquely encoded by two independent pathways for pseudomonic acid and pyrrothine in a novel plasmid. The aim of this review is to give an overview about the isolations, characterizations, synthesis, biosynthesis, bioactivities and mode of action of this unique family of dithiolopyrrolone natural products, focusing on the period from 1940s until now. PMID:24141227

  17. Biosynthesis of 2'-deoxycoformycin by Streptomyces antibioticus

    International Nuclear Information System (INIS)

    Hanvey, J.C.

    1986-01-01

    The biosynthesis of 2'-deoxycoformycin by Streptomyces antibioticus has been investigated. Previous studies indicated that a purine nycleoside is the precursor for ten of the eleven carbons of deoxycoformycin. It was proposed that carbon-7 of the seven-membered, 1,3-diazepine-ring of deoxycoformycin is not derived from the purine ring but by an insertion of a one-carbon unit between N-1 and C-6 of the purine ring. Carbon-1 of D-ribose has now been identified as the precursor for carbon 7 (and 1') of deoxycoformycin. Although the tetrahydrofolate/one-carbon pool contributes one carbon units to carbons-2 and 8 of the purine ring, which become carbons-5 and 2 of deoxycoformycin, it is not involved in the formation of carbon-7. The retention of the tritium on carbon-2 of [2,8- 3 H]-adenosine in deoxycoformycin indicates that guanosine is not the nucleoside precursor of deoxycoformycin. The failure to detect the incorporation of 18 O from [6- 18 O]-inosine in deoxycoformycin suggests that inosine is not the purine nucleoside precursor of deoxycoformycin. Therefore, it is proposed that adenosine and carbon-1 and d-ribose are the carbon-nitrogen precursors of deoxycoformycin. A mechanism for the insertion of carbon-1 of d-ribose into the pyrimidine portion of the purine ring has been proposed. Using cell-free extracts of S. antibioticus, 8-ketodeoxycoformycin and 8-ketocoformycin can be converted to deoxycoformycin and coformycin, respectively. The enzyme which reduces the 8-keto groups has been characterized and partially purified

  18. Distinguishing stress fractures from pathologic fractures: a multimodality approach

    International Nuclear Information System (INIS)

    Fayad, Laura M.; Kamel, Ihab R.; Kawamoto, Satomi; Bluemke, David A.; Fishman, Elliot K.; Frassica, Frank J.

    2005-01-01

    Whereas stress fractures occur in normal or metabolically weakened bones, pathologic fractures occur at the site of a bone tumor. Unfortunately, stress fractures may share imaging features with pathologic fractures on plain radiography, and therefore other modalities are commonly utilized to distinguish these entities. Additional cross-sectional imaging with CT or MRI as well as scintigraphy and PET scanning is often performed for further evaluation. For the detailed assessment of a fracture site, CT offers a high-resolution view of the bone cortex and periosteum which aids the diagnosis of a pathologic fracture. The character of underlying bone marrow patterns of destruction can also be ascertained along with evidence of a soft tissue mass. MRI, however, is a more sensitive technique for the detection of underlying bone marrow lesions at a fracture site. In addition, the surrounding soft tissues, including possible involvement of adjacent muscle, can be well evaluated with MRI. While bone scintigraphy and FDG-PET are not specific, they offer a whole-body screen for metastases in the case of a suspected malignant pathologic fracture. In this review, we present select examples of fractures that underscore imaging features that help distinguish stress fractures from pathologic fractures, since accurate differentiation of these entities is paramount. (orig.)

  19. Award for Distinguished Contributions to Education and Training in psychology.

    Science.gov (United States)

    2017-12-01

    This award is given by the Board of Educational Affairs in recognition of the efforts of psychologists who have made distinguished contributions to education and training, who have produced imaginative innovations, or who have been involved in the developmental phases of programs in education and training in psychology. These contributions might include important research on education and training; the development of effective materials for instruction; the establishment of workshops, conferences, or networks of communication for education and training; achievement and leadership in administration that facilitates education and training; or activity in professional organizations that promote excellence. The Award for Distinguished Contributions to Education and Training in psychology recognizes a specific contribution to education and training. The Career designation is added to the award at the discretion of the Education and Training Awards Committee to recognize continuous significant contributions made over a lifelong career in psychology. This year the Education and Training Awards Committee selected a psychologist for the Career designation. The 2017 recipients of the APA Education and Training Contributions Awards were selected by the 2016 Education and Training Awards Committee appointed by the Board of Educational Affairs (BEA). Members of the 2016 Education and Training Awards Committee were Erica Wise, PhD (Chair); Ron Rozensky, PhD; Jane D. Halonen, PhD; Sharon Berry, PhD (Chair Elect); Emil Rodolfa, PhD; and Sylvia A. Rosenfield, PhD. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. Distinguishing deterministic and noise components in ELM time series

    International Nuclear Information System (INIS)

    Zvejnieks, G.; Kuzovkov, V.N

    2004-01-01

    Full text: One of the main problems in the preliminary data analysis is distinguishing the deterministic and noise components in the experimental signals. For example, in plasma physics the question arises analyzing edge localized modes (ELMs): is observed ELM behavior governed by a complicate deterministic chaos or just by random processes. We have developed methodology based on financial engineering principles, which allows us to distinguish deterministic and noise components. We extended the linear auto regression method (AR) by including the non-linearity (NAR method). As a starting point we have chosen the nonlinearity in the polynomial form, however, the NAR method can be extended to any other type of non-linear functions. The best polynomial model describing the experimental ELM time series was selected using Bayesian Information Criterion (BIC). With this method we have analyzed type I ELM behavior in a subset of ASDEX Upgrade shots. Obtained results indicate that a linear AR model can describe the ELM behavior. In turn, it means that type I ELM behavior is of a relaxation or random type

  1. Causal topology in future and past distinguishing spacetimes

    Science.gov (United States)

    Parrikar, Onkar; Surya, Sumati

    2011-08-01

    The causal structure of a strongly causal spacetime is particularly well endowed. Not only does it determine the conformal spacetime geometry when the spacetime dimension n > 2, as shown by Malament and Hawking-King-McCarthy (MHKM), but also the manifold dimension. The MHKM result, however, applies more generally to spacetimes satisfying the weaker causality condition of future and past distinguishability (FPD), and it is an important question whether the causal structure of such spacetimes can determine the manifold dimension. In this work, we show that the answer to this question is in the affirmative. We investigate the properties of future or past distinguishing spacetimes and show that their causal structures determine the manifold dimension. This gives a non-trivial generalization of the MHKM theorem and suggests that there is a causal topology for FPD spacetimes which encodes manifold dimension and which is strictly finer than the Alexandrov topology. We show that such a causal topology does exist. We construct it using a convergence criterion based on sequences of 'chain intervals' which are the causal analogues of null geodesic segments. We show that when the region of strong causality violation satisfies a local achronality condition, this topology is equivalent to the manifold topology in an FPD spacetime.

  2. Causal topology in future and past distinguishing spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Parrikar, Onkar [Birla Institute of Technology and Science-Pilani, Goa campus, Goa 403 726 (India); Surya, Sumati, E-mail: ssurya@rri.res.in [Raman Research Institute, CV Raman Ave, Sadashivanagar, Bangalore 560 080 (India)

    2011-08-07

    The causal structure of a strongly causal spacetime is particularly well endowed. Not only does it determine the conformal spacetime geometry when the spacetime dimension n > 2, as shown by Malament and Hawking-King-McCarthy (MHKM), but also the manifold dimension. The MHKM result, however, applies more generally to spacetimes satisfying the weaker causality condition of future and past distinguishability (FPD), and it is an important question whether the causal structure of such spacetimes can determine the manifold dimension. In this work, we show that the answer to this question is in the affirmative. We investigate the properties of future or past distinguishing spacetimes and show that their causal structures determine the manifold dimension. This gives a non-trivial generalization of the MHKM theorem and suggests that there is a causal topology for FPD spacetimes which encodes manifold dimension and which is strictly finer than the Alexandrov topology. We show that such a causal topology does exist. We construct it using a convergence criterion based on sequences of 'chain intervals' which are the causal analogues of null geodesic segments. We show that when the region of strong causality violation satisfies a local achronality condition, this topology is equivalent to the manifold topology in an FPD spacetime.

  3. Useful tests on pleural fluid that distinguish transudates from exudates.

    Science.gov (United States)

    Porcel, J M; Vives, M; Vicente de Vera, M C; Cao, G; Rubio, M; Rivas, M C

    2001-11-01

    We aimed to compare the classic Light's criteria with different testing strategies in an effort to improve the accuracy of pleural fluid (PF) categorization. Thirty-two patients with transudates and 140 with exudates on the basis of their clinical diagnosis were entered into the study. We examined the discriminative properties of 10 analytes in the identification of PF, both singly and in combination with an 'or' rule, to see which was best in distinguishing a transudate from an exudate. A combination of PF lactate dehydrogenase (LD) > 307 U/L (two-thirds of the upper limit of the serum LD reference range) with either PF cholesterol > 1.55 mmol/L or PF to serum protein ratio > 0.5 had a diagnostic accuracy similar to that of Light's criteria. We suggest the use of PF LD and cholesterol in combination as an alternative method for distinguishing pleural transudates from exudates. This test combination avoids the need for venepuncture and the simultaneous collection of a blood sample.

  4. Effects of different concentarions of auxins on rooting and root ...

    African Journals Online (AJOL)

    The effect of auxins and their different concentrations on rooting and root characters of air and ground layers of jojoba was assessed at Maxima Estate Private Limited Farm, Hyderabad, India in 1998. Auxins IBA, NAA and their mixture (IBA + NAA) at concentrations of 1000, 2000, 4000 and 6000 ppm with lanolin paste were ...

  5. Radiographing roots and shoots

    International Nuclear Information System (INIS)

    Shariffah Noor Khamseah Al Idid

    1985-01-01

    The effect of seed orientation on germination time and on shoot and root growth patterns is studied. Neutron radiography is used to observe the development of 4 types of plants, maize, greenpea, soya bean and padi. These plants were grown in varying orientations; sand sizes, sand thicknesses, and level of water content. Radiography of the seeds and plants were obtained for time exposure ranging from 3-12 hours and at reactor thermal power level, ranging from 500-750 kilowatts. Results obtained showed that seeds planted in varying orientations need different length of time for shoot emergence. Neutron radiography is now developed to other areas of non-industrial applications in Malaysia. (A.J.)

  6. Back to the roots!

    DEFF Research Database (Denmark)

    Woermann, Niklas

    2017-01-01

    This article argues that one can revive the critical edge that postmodernist theory has brought to marketing, thinking without subscribing to any particular school of (critical) theory by following the principle of methodological situationalism. The roots of postmodernist critique lie in careful...... empirical observation of how social reality is being constructed in local contexts. Because knowledge, subjects, power, and value are social accomplishments, they are neither fixed nor without alternative. Many key developments in marketing theory such as assemblage theory, practice and consumer tribes...... of social order into account, hence fail to provide sensible insight. I propose the principle of methodological situationalism as a litmus test to the analytical strength of a theory or piece of research. The principle states that theoretically adequate accounts of social phenomena must be grounded...

  7. Antipeptide antibodies that can distinguish specific subunit polypeptides of glutamine synthetase from bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    Cai, X.; Henry, R. L.; Takemoto, L. J.; Guikema, J. A.; Wong, P. P.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The amino acid sequences of the beta and gamma subunit polypeptides of glutamine synthetase from bean (Phaseolus vulgaris L.) root nodules are very similar. However, there are small regions within the sequences that are significantly different between the two polypeptides. The sequences between amino acids 2 and 9 and between 264 and 274 are examples. Three peptides (gamma 2-9, gamma 264-274, and beta 264-274) corresponding to these sequences were synthesized. Antibodies against these peptides were raised in rabbits and purified with corresponding peptide-Sepharose affinity chromatography. Western blot analysis of polyacrylamide gel electrophoresis of bean nodule proteins demonstrated that the anti-beta 264-274 antibodies reacted specifically with the beta polypeptide and the anti-gamma 264-274 and anti-gamma 2-9 antibodies reacted specifically with the gamma polypeptide of the native and denatured glutamine synthetase. These results showed the feasibility of using synthetic peptides in developing antibodies that are capable of distinguishing proteins with similar primary structures.

  8. Reprogramming of Strawberry (Fragaria vesca) Root Transcriptome in Response to Phytophthora cactorum

    Science.gov (United States)

    Blande, Daniel; Kärenlampi, Sirpa; Kokko, Harri

    2016-01-01

    Crown rot (Phytophthora cactorum) causes significant economic losses in strawberry production. The best control strategy would be to use resistant cultivars, but polygenically inherited resistance makes the breeding of the garden strawberry (Fragaria × ananassa) challenging. The diploid wild strawberry Fragaria vesca Hawaii 4 genotype was shown previously to have resistance against crown rot. To explore the resistance mechanisms, we inoculated the roots of Hawaii 4 with P. cactorum in a novel in vitro hydroponic system to minimize interference caused by other microbes. Major reprogramming of the root transcriptome occurred, involving 30% of the genes. The surveillance system of the plant shifted from the development mode to the defense mode. Furthermore, the immune responses as well as many genes involved in the biosynthesis of the defense hormones jasmonic acid, ethylene and salicylic acid were up-regulated. Several major allergen-like genes encoding PR-10 proteins were highly expressed in the inoculated plants, suggesting that they also have a crucial role in the defense responses against P. cactorum. Additionally, flavonoids and terpenoids may be of vital importance, as several genes involved in their biosynthesis were up-regulated. The cell wall biosynthesis and developmental processes were down-regulated, possibly as a result of the down-regulation of the key genes involved in the biosynthesis of growth-promoting hormones brassinosteroids and auxin. Of particular interest was the expression of potential resistance genes in the recently identified P. cactorum resistance locus RPc-1. These new findings help to target the breeding efforts aiming at more resistant strawberry cultivars. PMID:27518577

  9. Reprogramming of Strawberry (Fragaria vesca) Root Transcriptome in Response to Phytophthora cactorum.

    Science.gov (United States)

    Toljamo, Anna; Blande, Daniel; Kärenlampi, Sirpa; Kokko, Harri

    2016-01-01

    Crown rot (Phytophthora cactorum) causes significant economic losses in strawberry production. The best control strategy would be to use resistant cultivars, but polygenically inherited resistance makes the breeding of the garden strawberry (Fragaria × ananassa) challenging. The diploid wild strawberry Fragaria vesca Hawaii 4 genotype was shown previously to have resistance against crown rot. To explore the resistance mechanisms, we inoculated the roots of Hawaii 4 with P. cactorum in a novel in vitro hydroponic system to minimize interference caused by other microbes. Major reprogramming of the root transcriptome occurred, involving 30% of the genes. The surveillance system of the plant shifted from the development mode to the defense mode. Furthermore, the immune responses as well as many genes involved in the biosynthesis of the defense hormones jasmonic acid, ethylene and salicylic acid were up-regulated. Several major allergen-like genes encoding PR-10 proteins were highly expressed in the inoculated plants, suggesting that they also have a crucial role in the defense responses against P. cactorum. Additionally, flavonoids and terpenoids may be of vital importance, as several genes involved in their biosynthesis were up-regulated. The cell wall biosynthesis and developmental processes were down-regulated, possibly as a result of the down-regulation of the key genes involved in the biosynthesis of growth-promoting hormones brassinosteroids and auxin. Of particular interest was the expression of potential resistance genes in the recently identified P. cactorum resistance locus RPc-1. These new findings help to target the breeding efforts aiming at more resistant strawberry cultivars.

  10. Siderophore Biosynthesis Governs the Virulence of Uropathogenic Escherichia coli by Coordinately Modulating the Differential Metabolism.

    Science.gov (United States)

    Su, Qiao; Guan, Tianbing; He, Yan; Lv, Haitao

    2016-04-01

    Urinary tract infections impose substantial health burdens on women worldwide. Urinary tract infections often incur a high risk of recurrence and antibiotic resistance, and uropathogenic E. coli accounts for approximately 80% of clinically acquired cases. The diagnosis of, treatment of, and drug development for urinary tract infections remain substantial challenges due to the complex pathogenesis of this condition. The clinically isolated UPEC 83972 strain was found to produce four siderophores: yersiniabactin, aerobactin, salmochelin, and enterobactin. The biosyntheses of some of these siderophores implies that the virulence of UPEC is mediated via the targeting of primary metabolism. However, the differential modulatory roles of siderophore biosyntheses on the differential metabolomes of UPEC and non-UPEC strains remain incompletely understood. In the present study, we sought to investigate how the differential metabolomes can be used to distinguish UPEC from non-UPEC strains and to determine the associated regulatory roles of siderophore biosynthesis. Our results are the first to demonstrate that the identified differential metabolomes strongly differentiated UPEC from non-UPEC strains. Furthermore, we performed metabolome assays of mutants with different patterns of siderophore deletions; the data revealed that the mutations of all four siderophores exerted a stronger modulatory role on the differential metabolomes of the UPEC and non-UPEC strains relative to the mutation of any single siderophore and that this modulatory role primarily involved amino acid metabolism, oxidative phosphorylation in the carbon fixation pathway, and purine and pyrimidine metabolism. Surprisingly, the modulatory roles were strongly dependent on the type and number of mutated siderophores. Taken together, these results demonstrated that siderophore biosynthesis coordinately modulated the differential metabolomes and thus may indicate novel targets for virulence-based diagnosis

  11. Dithiolopyrrolones: biosynthesis, synthesis, and activity of a unique class of disulfide-containing antibiotics.

    Science.gov (United States)

    Li, Bo; Wever, Walter J; Walsh, Christopher T; Bowers, Albert A

    2014-07-01

    Covering: up to 2014. Dithiolopyrrolone (DTP) group antibiotics were first isolated in the early half of the 20th century, but only recently has research been reawakened by insights gained from the synthesis and biosynthesis of this structurally intriguing class of molecules. DTPs are characterized by an electronically unique bicyclic structure, which contains a compact disulfide bridge between two ene-thiols. Points of diversity within the compound class occur outside of the bicyclic core, at the two amide nitrogens. Such modifications distinguish three of the most well studied members of the class, holomycin, thiolutin, and aureothricin; the DTP core has also more recently been identified in the marine antibiotic thiomarinol, in which it is linked to a marinolic acid moiety, analog of the FDA-approved topical antibiotic Bactroban® (GlaxoSmithKline). Dithiolopyrrolones exhibit relatively broad-spectrum antibiotic activity against many Gram-positive and Gram-negative bacteria, as well as strains of Mycobacterium tuberculosis. Additionally, they have been shown to exhibit potent and selective anti-cancer activity. Despite this promising profile, there is still much unknown about the mechanisms of action for DTPs. Early reports suggested that they inhibit yeast growth at the level of transcription and that this effect is largely responsible for their distinctive microbial static properties; a similar mechanism is supported in bacteria. Elucidation of biosynthetic pathways for holomycin in Streptomyces clavuligerus and Yersinia ruckeri and thiomarinol in Alteromonas rava sp. nov. SANK 73390, have contributed evidence suggesting that multiple mechanisms may be operative in the activity of these compounds. This review will comprehensively cover the history and development of dithiolopyrrolones with particular emphasis on the biosynthesis, synthesis, biological activity and mechanism of action.

  12. Abnormal Ergosterol Biosynthesis Activates Transcriptional Responses to Antifungal Azoles.

    Science.gov (United States)

    Hu, Chengcheng; Zhou, Mi; Wang, Wenzhao; Sun, Xianyun; Yarden, Oded; Li, Shaojie

    2018-01-01

    Fungi transcriptionally upregulate expression of azole efflux pumps and ergosterol biosynthesis pathway genes when exposed to antifungal agents that target ergosterol biosynthesis. To date, these transcriptional responses have been shown to be dependent on the presence of the azoles and/or depletion of ergosterol. Using an inducible promoter to regulate Neurospora crassa erg11 , which encodes the major azole target, sterol 14α-demethylase, we were able to demonstrate that the CDR4 azole efflux pump can be transcriptionally activated by ergosterol biosynthesis inhibition even in the absence of azoles. By analyzing ergosterol deficient mutants, we demonstrate that the transcriptional responses by cdr4 and, unexpectedly, genes encoding ergosterol biosynthesis enzymes ( erg genes) that are responsive to azoles, are not dependent on ergosterol depletion. Nonetheless, deletion of erg2 , which encodes C-8 sterol isomerase, also induced expression of cdr4 . Deletion of erg2 also induced the expression of erg24 , the gene encoding C-14 sterol reductase, but not other tested erg genes which were responsive to erg11 inactivation. This indicates that inhibition of specific steps of ergosterol biosynthesis can result in different transcriptional responses, which is further supported by our results obtained using different ergosterol biosynthesis inhibitors. Together with the sterol profiles, these results suggest that the transcriptional responses by cdr4 and erg genes are associated with accumulation of specific sterol intermediate(s). This was further supported by the fact that when the erg2 mutant was treated with ketoconazole, upstream inhibition overrode the effects by downstream inhibition on ergosterol biosynthesis pathway. Even though cdr4 expression is associated with the accumulation of sterol intermediates, intra- and extracellular sterol analysis by HPLC-MS indicated that the transcriptional induction of cdr4 did not result in efflux of the accumulated intermediate

  13. Stimulation of artemisinin biosynthesis in Artemisia annua hairy ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-06-07

    . Hairy root (HR3) of A. annua was used in this study, which was routinely ... H2O2 generation. H2O2 production from elicited hairy roots was measured by chemiluminescence method (Hu et al., 2003). The luminescence.

  14. Rhizosphere microbial community structure in relation to root location and plant iron nutritional status.

    Science.gov (United States)

    Yang, C H; Crowley, D E

    2000-01-01

    Root exudate composition and quantity vary in relation to plant nutritional status, but the impact of the differences on rhizosphere microbial communities is not known. To examine this question, we performed an experiment with barley (Hordeum vulgare) plants under iron-limiting and iron-sufficient growth conditions. Plants were grown in an iron-limiting soil in root box microcosms. One-half of the plants were treated with foliar iron every day to inhibit phytosiderophore production and to alter root exudate composition. After 30 days, the bacterial communities associated with different root zones, including the primary root tips, nonelongating secondary root tips, sites of lateral root emergence, and older roots distal from the tip, were characterized by using 16S ribosomal DNA (rDNA) fingerprints generated by PCR-denaturing gradient gel electrophoresis (DGGE). Our results showed that the microbial communities associated with the different root locations produced many common 16S rDNA bands but that the communities could be distinguished by using correspondence analysis. Approximately 40% of the variation between communities could be attributed to plant iron nutritional status. A sequence analysis of clones generated from a single 16S rDNA band obtained at all of the root locations revealed that there were taxonomically different species in the same band, suggesting that the resolving power of DGGE for characterization of community structure at the species level is limited. Our results suggest that the bacterial communities in the rhizosphere are substantially different in different root zones and that a rhizosphere community may be altered by changes in root exudate composition caused by changes in plant iron nutritional status.

  15. Mandibular molar root morphology in Neanderthals and Late Pleistocene and recent Homo sapiens.

    Science.gov (United States)

    Kupczik, Kornelius; Hublin, Jean-Jacques

    2010-11-01

    Neanderthals have a distinctive suite of dental features, including large anterior crown and root dimensions and molars with enlarged pulp cavities. Yet, there is little known about variation in molar root morphology in Neanderthals and other recent and fossil members of Homo. Here, we provide the first comprehensive metric analysis of permanent mandibular molar root morphology in Middle and Late Pleistocene Homo neanderthalensis, and Late Pleistocene (Aterian) and recent Homo sapiens. We specifically address the question of whether root form can be used to distinguish between these groups and assess whether any variation in root form can be related to differences in tooth function. We apply a microtomographic imaging approach to visualise and quantify the external and internal dental morphologies of both isolated molars and molars embedded in the mandible (n=127). Univariate and multivariate analyses reveal both similarities (root length and pulp volume) and differences (occurrence of pyramidal roots and dental tissue volume proportion) in molar root morphology among penecontemporaneous Neanderthals and Aterian H. sapiens. In contrast, the molars of recent H. sapiens are markedly smaller than both Pleistocene H. sapiens and Neanderthals, but share with the former the dentine volume reduction and a smaller root-to-crown volume compared with Neanderthals. Furthermore, we found the first molar to have the largest average root surface area in recent H. sapiens and Neanderthals, although in the latter the difference between M(1) and M(2) is small. In contrast, Aterian H. sapiens root surface areas peak at M(2). Since root surface area is linked to masticatory function, this suggests a distinct occlusal loading regime in Neanderthals compared with both recent and Pleistocene H. sapiens. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack

    Science.gov (United States)

    Huber, Meret; Epping, Janina; Schulze Gronover, Christian; Fricke, Julia; Aziz, Zohra; Brillatz, Théo; Swyers, Michael; Köllner, Tobias G.; Vogel, Heiko; Hammerbacher, Almuth; Triebwasser-Freese, Daniella; Robert, Christelle A. M.; Verhoeven, Koen; Preite, Veronica; Gershenzon, Jonathan; Erb, Matthias

    2016-01-01

    Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha), and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground. PMID:26731567

  17. A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack.

    Directory of Open Access Journals (Sweden)

    Meret Huber

    2016-01-01

    Full Text Available Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg. decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha, and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground.

  18. A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack.

    Science.gov (United States)

    Huber, Meret; Epping, Janina; Schulze Gronover, Christian; Fricke, Julia; Aziz, Zohra; Brillatz, Théo; Swyers, Michael; Köllner, Tobias G; Vogel, Heiko; Hammerbacher, Almuth; Triebwasser-Freese, Daniella; Robert, Christelle A M; Verhoeven, Koen; Preite, Veronica; Gershenzon, Jonathan; Erb, Matthias

    2016-01-01

    Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha), and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground.

  19. Jasmonate-induced biosynthesis of andrographolide in Andrographis paniculata.

    Science.gov (United States)

    Sharma, Shiv Narayan; Jha, Zenu; Sinha, Rakesh Kumar; Geda, Arvind Kumar

    2015-02-01

    Andrographolide is a prominent secondary metabolite found in Andrographis paniculata that exhibits enormous pharmacological effects. In spite of immense value, the normal biosynthesis of andrographolide results in low amount of the metabolite. To induce the biosynthesis of andrographolide, we attempted elicitor-induced activation of andrographolide biosynthesis in cell cultures of A. paniculata. This was carried out by using methyl jasmonate (MeJA) as an elicitor. Among the various concentrations of MeJA tested at different time periods, 5 µM MeJA yielded 5.25 times more andrographolide content after 24 h of treatment. The accumulation of andrographolide was correlated with the expression level of known regulatory genes (hmgs, hmgr, dxs, dxr, isph and ggps) of mevalonic acid (MVA) and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways. These results established the involvement of MeJA in andrographolide biosynthesis by inducing the transcription of its biosynthetic pathways genes. The coordination of isph, ggps and hmgs expression highly influenced the andrographolide biosynthesis. © 2014 Scandinavian Plant Physiology Society.

  20. Biosynthesis and functions of sulfur modifications in tRNA

    Directory of Open Access Journals (Sweden)

    Naoki eShigi

    2014-04-01

    Full Text Available Sulfur is an essential element for a variety of cellular constituents in all living organisms. In tRNA molecules, there are many sulfur-containing nucleosides, such as the derivatives of 2‑thiouridine (s2U, 4-thiouridine (s4U, 2-thiocytidine (s2C, and 2-methylthioadenosine (ms2A. Earlier studies established the functions of these modifications for accurate and efficient translation, including proper recognition of the codons in mRNA or stabilization of tRNA structure. In many cases, the biosynthesis of these sulfur modifications starts with cysteine desulfurases, which catalyze the generation of persulfide (an activated form of sulfur from cysteine. Many sulfur-carrier proteins are responsible for delivering this activated sulfur to each biosynthesis pathway. Finally, specific modification enzymes activate target tRNAs and then incorporate sulfur atoms. Intriguingly, the biosynthesis of 2-thiouridine in all domains of life is functionally and evolutionarily related to the ubiquitin-like post-translational modification system of cellular proteins in eukaryotes. This review summarizes the recent characterization of the biosynthesis of sulfur modifications in tRNA and the novel roles of this modification in cellular functions in various model organisms, with a special emphasis on 2-thiouridine derivatives. Each biosynthesis pathway of sulfur-containing molecules is mutually modulated via sulfur trafficking, and 2-thiouridine and codon usage bias have been proposed to control the translation of specific genes.

  1. Searching for Roots / Pierre Gervasoni

    Index Scriptorium Estoniae

    Gervasoni, Pierre

    1997-01-01

    Uuest heliplaadist "Searching for Roots. Eduard Tubin: Symphonie no 11; Arvo Pärt: Nekrolog-Symphonie no 1; Erkki-Sven Tüür: Searching for Roots - Insula deserta - Zeitraum; Orchestre philharmonique royal de Stockholm, Paavo Järvi (direction)" Virgin Classics 5 45212 2 (distribue par EMI)

  2. Cytokinin signaling during root development.

    Science.gov (United States)

    Bishopp, Anthony; Help, Hanna; Helariutta, Ykä

    2009-01-01

    The cytokinin class of phytohormones regulates division and differentiation of plant cells. They are perceived and signaled by a phosphorelay mechanism similar to those observed in prokaryotes. Research into the components of phosphorelay had previously been marred by genetic redundancy. However, recent studies have addressed this with the creation of high-order mutants. In addition, several new elements regulating cytokinin signaling have been identified. This has uncovered many roles in diverse developmental and physiological processes. In this review, we look at these processes specifically in the context of root development. We focus on the formation and maintenance of the root apical meristem, primary and secondary vascular development, lateral root emergence and development, and root nodulation. We believe that the root is an ideal organ with which to investigate cytokinin signaling in a wider context.

  3. Physical root-soil interactions.

    Science.gov (United States)

    Kolb, Evelyne; Legué, Valérie; Bogeat-Triboulot, Marie-Béatrice

    2017-11-16

    Plant root system development is highly modulated by the physical properties of the soil and especially by its mechanical resistance to penetration. The interplay between the mechanical stresses exerted by the soil and root growth is of particular interest for many communities, in agronomy and soil science as well as in biomechanics and plant morphogenesis. In contrast to aerial organs, roots apices must exert a growth pressure to penetrate strong soils and reorient their growth trajectory to cope with obstacles like stones or hardpans or to follow the tortuous paths of the soil porosity. In this review, we present the main macroscopic investigations of soil-root physical interactions in the field and combine them with simple mechanistic modeling derived from model experiments at the scale of the individual root apex.

  4. Roots of the Chromatic Polynomial

    DEFF Research Database (Denmark)

    Perrett, Thomas

    The chromatic polynomial of a graph G is a univariate polynomial whose evaluation at any positive integer q enumerates the proper q-colourings of G. It was introduced in connection with the famous four colour theorem but has recently found other applications in the field of statistical physics....... In this thesis we study the real roots of the chromatic polynomial, termed chromatic roots, and focus on how certain properties of a graph affect the location of its chromatic roots. Firstly, we investigate how the presence of a certain spanning tree in a graph affects its chromatic roots. In particular we prove...... of certain minor-closed families of graphs. Later, we study the Tutte polynomial of a graph, which contains the chromatic polynomial as a specialisation. We discuss a technique of Thomassen using which it is possible to deduce that the roots of the chromatic polynomial are dense in certain intervals. We...

  5. Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster.

    Science.gov (United States)

    Danjon, Frédéric; Caplan, Joshua S; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area or cross-sectional diameter (CSD) of a root and the dry weight of biomass (DWd) or root volume (Vd) that has grown (i.e., is descendent) from a point. Specification of this relationship allows one to quantify root architectural patterns and estimate the amount of material lost when root systems are extracted from the soil. However, specifications of this relationship generally do not account for the fact that root systems are comprised of multiple types of roots. We assessed whether the relationship between CSD and Vd varies as a function of root type. Additionally, we sought to identify a more accurate and time-efficient method for estimating missing root volume than is currently available. We used a database that described the 3D root architecture of Pinus pinaster root systems (5, 12, or 19 years) from a stand in southwest France. We determined the relationship between CSD and Vd for 10,000 root segments from intact root branches. Models were specified that did and did not account for root type. The relationships were then applied to the diameters of 11,000 broken root ends to estimate the volume of missing roots. CSD was nearly linearly related to the square root of Vd, but the slope of the curve varied greatly as a function of root type. Sinkers and deep roots tapered rapidly, as they were limited by available soil depth. Distal shallow roots tapered gradually, as they were less limited spatially. We estimated that younger trees lost an average of 17% of root volume when excavated, while older trees lost 4%. Missing volumes were smallest in the central parts of root systems and largest in distal shallow roots. The slopes of the curves for each root type are synthetic parameters that account for differentiation due to genetics, soil properties, or mechanical stimuli. Accounting for this differentiation is critical to estimating root loss accurately.

  6. Daniel M. Wegner: Award for Distinguished Scientific Contributions.

    Science.gov (United States)

    2011-11-01

    Presents Daniel M. Wegner, the 2011 winner of the American Psychological Association Award for Distinguished Scientific Contributions. "For seminal contributions that span psychology's breadth--from cognitive to social to personality to clinical--and that reach beyond its borders to philosophy and neuroscience. Daniel M. Wegner's studies on transactive memory, action identification, ironic processes, and apparent mental causation all bear his characteristic mark: a beautiful idea brought to life by an elegant experiment. He has spent his scientific career identifying new and important problems and then offering solutions that sparkle with originality and insight. He has seen doors where others saw walls, opened them to reveal new rooms, and illuminated their dark corners." (PsycINFO Database Record (c) 2011 APA, all rights reserved). 2011 APA, all rights reserved

  7. Distinguishing high surf from volcanic long-period earthquakes

    Science.gov (United States)

    Lyons, John; Haney, Matt; Fee, David; Paskievitch, John F.

    2014-01-01

    Repeating long-period (LP) earthquakes are observed at active volcanoes worldwide and are typically attributed to unsteady pressure fluctuations associated with fluid migration through the volcanic plumbing system. Nonvolcanic sources of LP signals include ice movement and glacial outburst floods, and the waveform characteristics and frequency content of these events often make them difficult to distinguish from volcanic LP events. We analyze seismic and infrasound data from an LP swarm recorded at Pagan volcano on 12–14 October 2013 and compare the results to ocean wave data from a nearby buoy. We demonstrate that although the events show strong similarity to volcanic LP signals, the events are not volcanic but due to intense surf generated by a passing typhoon. Seismo-acoustic methods allow for rapid distinction of volcanic LP signals from those generated by large surf and other sources, a critical task for volcano monitoring.

  8. A distinguishing gravitational property for gravitational equation in higher dimensions

    International Nuclear Information System (INIS)

    Dadhich, Naresh

    2016-01-01

    It is well known that Einstein gravity is kinematic (meaning that there is no non-trivial vacuum solution; i.e. the Riemann tensor vanishes whenever the Ricci tensor does so) in 3 dimension because the Riemann tensor is entirely given in terms of the Ricci tensor. Could this property be universalized for all odd dimensions in a generalized theory? The answer is yes, and this property uniquely singles out pure Lovelock (it has only one Nth order term in the action) gravity for which the Nth order Lovelock-Riemann tensor is indeed given in terms of the corresponding Ricci tensor for all odd, d = 2N + 1, dimensions. This feature of gravity is realized only in higher dimensions and it uniquely picks out pure Lovelock gravity from all other generalizations of Einstein gravity. It serves as a good distinguishing and guiding criterion for the gravitational equation in higher dimensions. (orig.)

  9. What distinguishes passive recipients from active decliners of sales flyers

    DEFF Research Database (Denmark)

    Jensen, Birger Boutrup; Orquin, Jacob Lund; Bech-Larsen, Tino

    2014-01-01

    While sales flyer ad spending in Denmark has increased over the last decade ,the proportion of consumers declining to receive such flyers has been ever-increasing. To address this paradox, attitudinal and behavioural factors distinguishing passive recipients from active decliners of sales flyers...... are examined. The results reveal that decliners compared to receivers are less price conscious and that they perceive flyers as more inconvenient and less useful. Although decliners generally use other media less for deal searching than receivers, they are more inclined to search for grocery deals...... on the Internet.To reach the decliners, retailers could focus on the possibilities of the Internet, but to stop the trend of escalating numbers of decliners, retailers will have to address the perceived inconvenience and uselessness of sales flyers....

  10. Chamber catalogues of optical and fluorescent signatures distinguish bioaerosol classes

    Science.gov (United States)

    Hernandez, Mark; Perring, Anne E.; McCabe, Kevin; Kok, Greg; Granger, Gary; Baumgardner, Darrel

    2016-07-01

    Rapid bioaerosol characterization has immediate applications in the military, environmental and public health sectors. Recent technological advances have facilitated single-particle detection of fluorescent aerosol in near real time; this leverages controlled ultraviolet exposures with single or multiple wavelengths, followed by the characterization of associated fluorescence. This type of ultraviolet induced fluorescence has been used to detect airborne microorganisms and their fragments in laboratory studies, and it has been extended to field studies that implicate bioaerosol to compose a substantial fraction of supermicron atmospheric particles. To enhance the information yield that new-generation fluorescence instruments can provide, we report the compilation of a referential aerobiological catalogue including more than 50 pure cultures of common airborne bacteria, fungi and pollens, recovered at water activity equilibrium in a mesoscale chamber (1 m3). This catalogue juxtaposes intrinsic optical properties and select bandwidths of fluorescence emissions, which manifest to clearly distinguish between major classes of airborne microbes and pollens.

  11. Remotely Distinguishing and Mapping Endogenic Water on the Moon

    Science.gov (United States)

    Klima, Rachel L.; Petro, Noah E.

    2017-01-01

    Water and/or hydroxyl detected remotely on the lunar surface originates from several sources: (i) comets and other exogenous debris; (ii) solar wind implantation; (iii) the lunar interior. While each of these sources is interesting in its own right, distinguishing among them is critical for testing hypotheses for the origin and evolution of the Moon and our Solar System. Existing spacecraft observations are not of high enough spectral resolution to uniquely characterize the bonding energies of the hydroxyl molecules that have been detected. Nevertheless, the spatial distribution and associations of H, OH- or H2O with specific lunar lithologies provide some insight into the origin of lunar hydrous materials. The global distribution of OH-/H2O as detected using infrared spectroscopic measurements from orbit is here examined, with particular focus on regional geological features that exhibit OH-/H2O absorption band strengths that differ from their immediate surroundings.

  12. Genetic profiles distinguish different types of hereditary ovarian cancer

    DEFF Research Database (Denmark)

    Domanska, Katarina; Malander, Susanne; Staaf, Johan

    2010-01-01

    Heredity represents the strongest risk factor for ovarian cancer with disease predisposing mutations identified in 15% of the tumors. With the aim to identify genetic classifiers for hereditary ovarian cancer, we profiled hereditary ovarian cancers linked to the hereditary breast and ovarian canc...... that HBOC and HNPCC associated ovarian cancer develop along distinct genetic pathways and genetic profiles can thus be applied to distinguish between different types of hereditary ovarian cancer.......Heredity represents the strongest risk factor for ovarian cancer with disease predisposing mutations identified in 15% of the tumors. With the aim to identify genetic classifiers for hereditary ovarian cancer, we profiled hereditary ovarian cancers linked to the hereditary breast and ovarian cancer...... (HBOC) syndrome and the hereditary non-polyposis colorectal cancer (HNPCC) syndrome. Genome-wide array comparative genomic hybridization was applied to 12 HBOC associated tumors with BRCA1 mutations and 8 HNPCC associated tumors with mismatch repair gene mutations with 24 sporadic ovarian cancers...

  13. Award for Distinguished Contributions to the International Advancement of Psychology.

    Science.gov (United States)

    2017-12-01

    This award is given to individuals who have made sustained and enduring contributions to international cooperation and the advancement of knowledge in psychology. The 2017 recipient of the APA Award for Distinguished Contributions to the International Advancement of Psychology was selected by the 2016 Committee on International Relations in Psychology (CIRP). The members of the 2016 CIRP were Melissa Morgan Consoli, PhD, and Arpana G. Inman, PhD (Co-chairs); Rehman Abdulrehman, PhD; Gonzalo Bacigalupe, EdD; Frederic Bemak, EdD; Brigitte Khoury, PhD; Susan Nolan, PhD; Nancy Sidun, PsyD; and Danny Wedding, PhD. Dr. Morgan Consoli, Dr. Inman, Dr. Nolan, and Doctor Sidun were members of the subcommittee for the 2017 award. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. RootJS: Node.js Bindings for ROOT 6

    Science.gov (United States)

    Beffart, Theo; Früh, Maximilian; Haas, Christoph; Rajgopal, Sachin; Schwabe, Jonas; Wolff, Christoph; Szuba, Marek

    2017-10-01

    We present rootJS, an interface making it possible to seamlessly integrate ROOT 6 into applications written for Node.js, the JavaScript runtime platform increasingly commonly used to create high-performance Web applications. ROOT features can be called both directly from Node.js code and by JIT-compiling C++ macros. All rootJS methods are invoked asynchronously and support callback functions, allowing non-blocking operation of Node.js applications using them. Last but not least, our bindings have been designed to platform-independent and should therefore work on all systems supporting both ROOT 6 and Node.js. Thanks to rootJS it is now possible to create ROOT-aware Web applications taking full advantage of the high performance and extensive capabilities of Node.js. Examples include platforms for the quality assurance of acquired, reconstructed or simulated data, book-keeping and e-log systems, and even Web browser-based data visualisation and analysis.

  15. Simulated multipolarized MAPSAR images to distinguish agricultural crops

    Directory of Open Access Journals (Sweden)

    Wagner Fernando Silva

    2012-06-01

    Full Text Available Many researchers have shown the potential of Synthetic Aperture Radar (SAR images for agricultural applications, particularly for monitoring regions with limitations in terms of acquiring cloud free optical images. Recently, Brazil and Germany began a feasibility study on the construction of an orbital L-band SAR sensor referred to as MAPSAR (Multi-Application Purpose SAR. This sensor provides L-band images in three spatial resolutions and polarimetric, interferometric and stereoscopic capabilities. Thus, studies are needed to evaluate the potential of future MAPSAR images. The objective of this study was to evaluate multipolarized MAPSAR images simulated by the airborne SAR-R99B sensor to distinguish coffee, cotton and pasture fields in Brazil. Discrimination among crops was evaluated through graphical and cluster analysis of mean backscatter values, considering single, dual and triple polarizations. Planting row direction of coffee influenced the backscatter and was divided into two classes: parallel and perpendicular to the sensor look direction. Single polarizations had poor ability to discriminate the crops. The overall accuracies were less than 59 %, but the understanding of the microwave interaction with the crops could be explored. Combinations of two polarizations could differentiate various fields of crops, highlighting the combination VV-HV that reached 78 % overall accuracy. The use of three polarizations resulted in 85.4 % overall accuracy, indicating that the classes pasture and parallel coffee were fully discriminated from the other classes. These results confirmed the potential of multipolarized MAPSAR images to distinguish the studied crops and showed considerable improvement in the accuracy of the results when the number of polarizations was increased.

  16. Using MT2 to distinguish dark matter stabilization symmetries

    International Nuclear Information System (INIS)

    Agashe, Kaustubh; Kim, Doojin; Zhu Lijun; Walker, Devin G. E.

    2011-01-01

    We examine the potential of using colliders to distinguish models with parity (Z 2 ) stabilized dark matter (DM) from models in which the DM is stabilized by other symmetries, taking the latter to be a Z 3 symmetry for illustration. The key observation is that a heavier mother particle charged under a Z 3 stabilization symmetry can decay into one or two DM particles along with standard model particles. This can be contrasted with the decay of a mother particle charged under a parity symmetry; typically, only one DM particle appears in the decay chain. The arXiv:1003.0899 studied the distributions of visible invariant mass from the decay of a single such mother particle in order to highlight the resulting distinctive signatures of Z 3 symmetry versus parity symmetry stabilized dark matter candidates. We now describe a complementary study which focuses on decay chains of the two mother particles which are necessarily present in these events. We also include in our analysis the missing energy/momentum in the event. For the Z 3 symmetry stabilized mothers, the resulting inclusive final state can have two, three or four DM particles. In contrast, models with Z 2 symmetry can have only two. We show that the shapes and edges of the distribution of M T2 -type variables, along with ratio of the visible momentum/energy on the two sides of the event, are powerful in distinguishing these different scenarios. Finally we conclude by outlining future work which focuses on reducing combinatoric ambiguities from reconstructing multijet events. Increasing the reconstruction efficiency can allow better reconstruction of events with two or three dark matter candidates in the final state.

  17. Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

    Directory of Open Access Journals (Sweden)

    Joshua D. Campbell

    2018-04-01

    Full Text Available Summary: This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs from five sites associated with smoking and/or human papillomavirus (HPV. SCCs harbor 3q, 5p, and other recurrent chromosomal copy-number alterations (CNAs, DNA mutations, and/or aberrant methylation of genes and microRNAs, which are correlated with the expression of multi-gene programs linked to squamous cell stemness, epithelial-to-mesenchymal differentiation, growth, genomic integrity, oxidative damage, death, and inflammation. Low-CNA SCCs tended to be HPV(+ and display hypermethylation with repression of TET1 demethylase and FANCF, previously linked to predisposition to SCC, or harbor mutations affecting CASP8, RAS-MAPK pathways, chromatin modifiers, and immunoregulatory molecules. We uncovered hypomethylation of the alternative promoter that drives expression of the ΔNp63 oncogene and embedded miR944. Co-expression of immune checkpoint, T-regulatory, and Myeloid suppressor cells signatures may explain reduced efficacy of immune therapy. These findings support possibilities for molecular classification and therapeutic approaches. : Campbell et al. reveal that squamous cell cancers from different tissue sites may be distinguished from other cancers and subclassified molecularly by recurrent alterations in chromosomes, DNA methylation, messenger and microRNA expression, or by mutations. These affect squamous cell pathways and programs that provide candidates for therapy. Keywords: genomics, transcriptomics, proteomics, head and neck squamous cell carcinoma, lung squamous cell carcinoma, esophageal squamous cell carcinoma, cervical squamous cell carcinoma, bladder carcinoma with squamous differentiation, human papillomavirus

  18. Generalized Pauli principle for particles with distinguishable traits.

    Science.gov (United States)

    Liu, Dan; Vanasse, Jared; Müller, Gerhard; Karbach, Michael

    2012-01-01

    The s=3/2 Ising spin chain with uniform nearest-neighbor coupling, quadratic single-site potential, and magnetic field is shown to be equivalent to a system of 17 species of particles with internal structure. The same set of particles (with different energies) is shown to generate the spectrum of the s=1/2 Ising chain with dimerized nearest-neighbor coupling. The particles are free of interaction energies even at high densities. The mutual exclusion statistics of particles from all species is determined by their internal structure and encoded in a generalized Pauli principle. The exact statistical mechanical analysis can be performed for thermodynamically open or closed systems and with arbitrary energies assigned to all particle species. Special circumstances make it possible to merge two or more species into a single species. All traits that distinguish the original species become ignorable. The particles from the merged species are effectively indistinguishable and obey modified exclusion statistics. Different mergers may yield the same end product, implying that the inverse process (splitting any species into subspecies) is not unique. In a macroscopic system of two merged species at thermal equilibrium, the concentrations of the original species satisfy a functional relation governed by their mutual statistical interaction. That relation is derivable from an extremum principle. In the Ising context the system is open and the particle energies depend on the Hamiltonian parameters. Simple models of polymerization and solitonic paramagnetism each represent a closed system of two species that can transform into each other. Here they represent distinguishable traits with different energies of the same physical particle. © 2012 American Physical Society

  19. Purine Biosynthesis Metabolically Constrains Intracellular Survival of Uropathogenic Escherichia coli

    Science.gov (United States)

    Shaffer, Carrie L.; Zhang, Ellisa W.; Dudley, Anne G.; Dixon, Beverly R. E. A.; Guckes, Kirsten R.; Breland, Erin J.; Floyd, Kyle A.; Casella, Daniel P.; Algood, Holly M. Scott; Clayton, Douglass B.

    2016-01-01

    ABSTRACT The ability to de novo synthesize purines has been associated with the intracellular survival of multiple bacterial pathogens. Uropathogenic Escherichia coli (UPEC), the predominant cause of urinary tract infections, undergoes a transient intracellular lifestyle during which bacteria clonally expand into multicellular bacterial communities within the cytoplasm of bladder epithelial cells. Here, we characterized the contribution of the conserved de novo purine biosynthesis-associated locus cvpA-purF to UPEC pathogenesis. Deletion of cvpA-purF, or of purF alone, abolished de novo purine biosynthesis but did not impact bacterial adherence properties in vitro or in the bladder lumen. However, upon internalization by bladder epithelial cells, UPEC deficient in de novo purine biosynthesis was unable to expand into intracytoplasmic bacterial communities over time, unless it was extrachromosomally complemented. These findings indicate that UPEC is deprived of purine nucleotides within the intracellular niche and relies on de novo purine synthesis to meet this metabolic requirement. PMID:27795353

  20. NAD+ biosynthesis, aging, and disease [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Sean Johnson

    2018-02-01

    Full Text Available Nicotinamide adenine dinucleotide (NAD+ biosynthesis and its regulation have recently been attracting markedly increasing interest. Aging is marked by a systemic decrease in NAD+ across multiple tissues. The dysfunction of NAD+ biosynthesis plays a critical role in the pathophysiologies of multiple diseases, including age-associated metabolic disorders, neurodegenerative diseases, and mental disorders. As downstream effectors, NAD+-dependent enzymes, such as sirtuins, are involved in the progression of such disorders. These recent studies implicate NAD+ biosynthesis as a potential target for preventing and treating age-associated diseases. Indeed, new studies have demonstrated the therapeutic potential of supplementing NAD+ intermediates, such as nicotinamide mononucleotide and nicotinamide riboside, providing a proof of concept for the development of an effective anti-aging intervention.

  1. Zincophorin – biosynthesis in Streptomyces griseus and antibiotic properties

    Directory of Open Access Journals (Sweden)

    Walther, Elisabeth

    2016-11-01

    Full Text Available Zincophorin is a polyketide antibiotic that possesses potent activity against Gram-positive bacteria, including human pathogens. While a number of total syntheses of this highly functionalized natural product were reported since its initial discovery, the genetic basis for the biosynthesis of zincophorin has remained unclear. In this study, the co-linearity inherent to polyketide pathways was used to identify the zincophorin biosynthesis gene cluster in the genome of the natural producer HKI 0741. Interestingly, the same locus is fully conserved in the streptomycin-producing actinomycete IFO 13350, suggesting that the latter bacterium is also capable of zincophorin biosynthesis. Biological profiling of zincophorin revealed a dose-dependent inhibition of the Gram-positive bacterium . The antibacterial effect, however, is accompanied by cytotoxicity. Antibiotic and cytotoxic activities were completely abolished upon esterification of the carboxylic acid group in zincophorin.

  2. Genes Involved in the Biosynthesis and Transport of Acinetobactin in

    Directory of Open Access Journals (Sweden)

    Tarik Hasan

    2015-03-01

    Full Text Available Pathogenic bacteria survive in iron-limited host environments by using several iron acquisition mechanisms. Acinetobacter baumannii, causing serious infections in compromised patients, produces an iron-chelating molecule, called acinetobactin, which is composed of equimolar quantities of 2,3-dihydroxybenzoic acid (DHBA, L-threonine, and N-hydroxyhistamine, to compete with host cells for iron. Genes that are involved in the production and transport of acinetobactin are clustered within the genome of A. baumannii. A recent study showed that entA, located outside of the acinetobactin gene cluster, plays important roles in the biosynthesis of the acinetobactin precursor DHBA and in bacterial pathogenesis. Therefore, understanding the genes that are associated with the biosynthesis and transport of acinetobactin in the bacterial genome is required. This review is intended to provide a general overview of the genes in the genome of A. baumannii that are required for acinetobactin biosynthesis and transport.

  3. Inhibitors of amino acids biosynthesis as antifungal agents.

    Science.gov (United States)

    Jastrzębowska, Kamila; Gabriel, Iwona

    2015-02-01

    Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of amino acids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.

  4. Some aspects of genetic control of antibiotic biosynthesis in Streptomyces

    Directory of Open Access Journals (Sweden)

    М. P. Teplitskaya

    2005-12-01

    Full Text Available These work contain a review of basic hypotheses and experimental information in relation to the problem of antibiotic synthesis regulation by the bacteria of the Streptomyces family. Data on cluster organization of antibiotics biosynthesis genes in these microorganisms were generalized. The examples of the positive and negative specific control of antibiotic production genes were resulted. Except for it, proofs that confirm participation of a few genes of more high level in the process of initiation and expression of antibiotics biosynthesis genes also were found. In this connection А-factor role in the mechanism of cascade-organized process of streptomycin biosynthesis control, some other antibiotics and spore determinations is discussed in detail.

  5. Methyl Transfer in Glucosinolate Biosynthesis Mediated by Indole Glucosinolate O-Methyltransferase 5.

    Science.gov (United States)

    Pfalz, Marina; Mukhaimar, Maisara; Perreau, François; Kirk, Jayne; Hansen, Cecilie Ida Cetti; Olsen, Carl Erik; Agerbirk, Niels; Kroymann, Juergen

    2016-12-01

    Indole glucosinolates (IGs) are plant secondary metabolites that are derived from the amino acid tryptophan. The product of Arabidopsis (Arabidopsis thaliana) IG core biosynthesis, indol-3-ylmethyl glucosinolate (I3M), can be modified by hydroxylation and subsequent methoxylation of the indole ring in position 1 (1-IG modification) or 4 (4-IG modification). Products of the 4-IG modification pathway mediate plant-enemy interactions and are particularly important for Arabidopsis innate immunity. While CYP81Fs encoding cytochrome P450 monooxygenases and IGMTs encoding indole glucosinolate O-methyltransferases have been identified as key genes for IG modification, our knowledge about the IG modification pathways is not complete. In particular, it is unknown which enzyme is responsible for methyl transfer in the 1-IG modification pathway and whether this pathway plays a role in defense, similar to 4-IG modification. Here, we analyze two Arabidopsis transfer DNA insertion lines with targeted metabolomics. We show that biosynthesis of 1-methoxyindol-3-ylmethyl glucosinolate (1MOI3M) from I3M involves the predicted unstable intermediate 1-hydroxyindol-3-ylmethyl glucosinolate (1OHI3M) and that IGMT5, a gene with moderate similarity to previously characterized IGMTs, encodes the methyltransferase that is responsible for the conversion of 1OHI3M to 1MOI3M. Disruption of IGMT5 function increases resistance against the root-knot nematode Meloidogyne javanica and suggests a potential role for the 1-IG modification pathway in Arabidopsis belowground defense. © 2016 American Society of Plant Biologists. All Rights Reserved.

  6. Molecular Evolution and Functional Characterization of a Bifunctional Decarboxylase Involved in Lycopodium Alkaloid Biosynthesis1[OPEN

    Science.gov (United States)

    Bunsupa, Somnuk; Hanada, Kousuke; Maruyama, Akira; Aoyagi, Kaori; Komatsu, Kana; Ueno, Hideki; Yamashita, Madoka; Sasaki, Ryosuke; Oikawa, Akira; Yamazaki, Mami

    2016-01-01

    Lycopodium alkaloids (LAs) are derived from lysine (Lys) and are found mainly in Huperziaceae and Lycopodiaceae. LAs are potentially useful against Alzheimer’s disease, schizophrenia, and myasthenia gravis. Here, we cloned the bifunctional lysine/ornithine decarboxylase (L/ODC), the first gene involved in LA biosynthesis, from the LA-producing plants Lycopodium clavatum and Huperzia serrata. We describe the in vitro and in vivo functional characterization of the L. clavatum L/ODC (LcL/ODC). The recombinant LcL/ODC preferentially catalyzed the decarboxylation of l-Lys over l-ornithine (l-Orn) by about 5 times. Transient expression of LcL/ODC fused with the amino or carboxyl terminus of green fluorescent protein, in onion (Allium cepa) epidermal cells and Nicotiana benthamiana leaves, showed LcL/ODC localization in the cytosol. Transgenic tobacco (Nicotiana tabacum) hairy roots and Arabidopsis (Arabidopsis thaliana) plants expressing LcL/ODC enhanced the production of a Lys-derived alkaloid, anabasine, and cadaverine, respectively, thus, confirming the function of LcL/ODC in plants. In addition, we present an example of the convergent evolution of plant Lys decarboxylase that resulted in the production of Lys-derived alkaloids in Leguminosae (legumes) and Lycopodiaceae (clubmosses). This convergent evolution event probably occurred via the promiscuous functions of the ancestral Orn decarboxylase, which is an enzyme involved in the primary metabolism of polyamine. The positive selection sites were detected by statistical analyses using phylogenetic trees and were confirmed by site-directed mutagenesis, suggesting the importance of those sites in granting the promiscuous function to Lys decarboxylase while retaining the ancestral Orn decarboxylase function. This study contributes to a better understanding of LA biosynthesis and the molecular evolution of plant Lys decarboxylase. PMID:27303024

  7. 4-coumarate: CoA ligase partitions metabolites for eugenol biosynthesis.

    Science.gov (United States)

    Rastogi, Shubhra; Kumar, Ritesh; Chanotiya, Chandan S; Shanker, Karuna; Gupta, Madan M; Nagegowda, Dinesh A; Shasany, Ajit K

    2013-08-01

    Biosynthesis of eugenol shares its initial steps with that of lignin, involving conversion of hydroxycinnamic acids to their corresponding coenzyme A (CoA) esters by 4-coumarate:CoA ligases (4CLs). In this investigation, a 4CL (OS4CL) was identified from glandular trichome-rich tissue of Ocimum sanctum with high sequence similarity to an isoform (OB4CL_ctg4) from Ocimum basilicum. The levels of OS4CL and OB4CL_ctg4-like transcripts were highest in O. sanctum trichome, followed by leaf, stem and root. The eugenol content in leaf essential oil was positively correlated with the expression of OS4CL in the leaf at different developmental stages. Recombinant OS4CL showed the highest activity with p-coumaric acid, followed by ferulic, caffeic and trans-cinnamic acids. Transient RNA interference (RNAi) suppression of OS4CL in O. sanctum leaves caused a reduction in leaf eugenol content and trichome transcript level, with a considerable increase in endogenous p-coumaric, ferulic, trans-cinnamic and caffeic acids. A significant reduction in the expression levels was observed for OB4CL_ctg4-related transcripts in suppressed trichome compared with transcripts similar to the other four isoforms (OB4CL_ctg1, 2, 3 and 5). Sinapic acid and lignin content were also unaffected in RNAi suppressed leaf samples. Transient expression of OS4CL-green fluorescent protein fusion protein in Arabidopsis protoplasts was associated with the cytosol. These results indicate metabolite channeling of intermediates towards eugenol by a specific 4CL and is the first report demonstrating the involvement of 4CL in creation of virtual compartments through substrate utilization and committing metabolites for eugenol biosynthesis at an early stage of the pathway.

  8. Increased root hair density by loss of WRKY6 in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Markus G. Stetter

    2017-01-01

    Full Text Available Root hairs are unicellular elongations of certain rhizodermal cells that improve the uptake of sparingly soluble and immobile soil nutrients. Among different Arabidopsis thaliana genotypes, root hair density, length and the local acclimation to low inorganic phosphate (Pi differs considerably, when analyzed on split agar plates. Here, genome-wide association fine mapping identified significant single nucleotide polymorphisms associated with the increased root hair density in the absence of local phosphate on chromosome 1. A loss-of-functionmutant of the candidate transcription factor gene WRKY6, which is involved in the acclimation of plants to low phosphorus, had increased root hair density. This is partially explained by a reduced cortical cell diameter in wrky6-3, reducing the rhizodermal cell numbers adjacent to the cortical cells. As a consequence, rhizodermal cells in positions that are in contact with two cortical cells are found more often, leading to higher hair density. Distinct cortical cell diameters and epidermal cell lengths distinguish other Arabidopsis accessions with distinct root hair density and −Pi response from diploid Col-0, while tetraploid Col-0 had generally larger root cell sizes, which explain longer hairs. A distinct radial root morphology within Arabidopsis accessions and wrky6-3explains some, but not all, differences in the root hair acclimation to –Pi.

  9. Examining the transcriptional response of overexpressing anthranilate synthase in the hairy roots of an important medicinal plant Catharanthus roseus by RNA-seq.

    Science.gov (United States)

    Sun, Jiayi; Manmathan, Harish; Sun, Cheng; Peebles, Christie A M

    2016-05-06

    Clinically important anti-cancer drugs vinblastine and vincristine are solely synthesized by the terpenoid indole alkaloid (TIA) pathway in Catharanthus roseus. Anthranilate synthase (AS) is a rate-limiting enzyme in the TIA pathway. The transgenic C. roseus hairy root line overexpressing a feedback insensitive ASα subunit under the control of an inducible promoter and the ASβ subunit constitutively was previously created for the overproduction of TIAs. However, both increases and decreases in TIAs were detected after overexpressing ASα. Although genetic modification is targeted to one gene in the TIA pathway, it could trigger global transcriptional changes that can directly or indirectly affect TIA biosynthesis. In this study, Illumina sequencing and RT-qPCR were used to detect the transcriptional responses to overexpressing AS, which can increase understanding of the complex regulation of the TIA pathway and further inspire rational metabolic engineering for enhanced TIA production in C. roseus hairy roots. Overexpressing AS in C. roseus hairy roots altered the transcription of most known TIA pathway genes and regulators after 12, 24, and 48 h induction detected by RT-qPCR. Changes in the transcriptome of C. roseus hairy roots was further investigated 18 hours after ASα induction and compared to the control hairy roots using RNA-seq. A unigene set of 30,281 was obtained by de novo assembly of the sequencing reads. Comparison of the differentially expressed transcriptional profiles resulted in 2853 differentially expressed transcripts. Functional annotation of these transcripts revealed a complex and systematically transcriptome change in ASαβ hairy roots. Pathway analysis shows alterations in many pathways such as aromatic amino acid biosynthesis, jasmonic acid (JA) biosynthesis and other secondary metabolic pathways after perturbing AS. Moreover, many genes in overall stress response were differentially expressed after overexpressing ASα. The

  10. Medico-legal aspects of vertical root fractures in root filled teeth

    DEFF Research Database (Denmark)

    Rosen, E; Tsesis, I; Tamse, A

    2012-01-01

    To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT).......To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT)....

  11. Recent advances in combinatorial biosynthesis for drug discovery

    Directory of Open Access Journals (Sweden)

    Sun H

    2015-02-01

    Full Text Available Huihua Sun,1,* Zihe Liu,1,* Huimin Zhao,1,2 Ee Lui Ang1 1Metabolic Engineering Research Laboratory, Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, Singapore; 2Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA *These authors contributed equally to this work Abstract: Because of extraordinary structural diversity and broad biological activities, natural products have played a significant role in drug discovery. These therapeutically important secondary metabolites are assembled and modified by dedicated biosynthetic pathways in their host living organisms. Traditionally, chemists have attempted to synthesize natural product analogs that are important sources of new drugs. However, the extraordinary structural complexity of natural products sometimes makes it challenging for traditional chemical synthesis, which usually involves multiple steps, harsh conditions, toxic organic solvents, and byproduct wastes. In contrast, combinatorial biosynthesis exploits substrate promiscuity and employs engineered enzymes and pathways to produce novel “unnatural” natural products, substantially expanding the structural diversity of natural products with potential pharmaceutical value. Thus, combinatorial biosynthesis provides an environmentally friendly way to produce natural product analogs. Efficient expression of the combinatorial biosynthetic pathway in genetically tractable heterologous hosts can increase the titer of the compound, eventually resulting in less expensive drugs. In this review, we will discuss three major strategies for combinatorial biosynthesis: 1 precursor-directed biosynthesis; 2 enzyme-level modification, which includes swapping of the entire domains, modules and subunits, site-specific mutagenesis, and directed evolution; 3 pathway-level recombination. Recent examples of combinatorial biosynthesis employing these

  12. Root and leaf abscisic acid concentration impact on gas exchange in tomato (Lycopersicon esculentum Mill plants subjected to partial root-zone drying

    Directory of Open Access Journals (Sweden)

    Maria Valerio

    2017-03-01

    Full Text Available Partial root-zone drying (PRD is a deficit irrigation technique with great potential for water saving. A split-root experiment was conducted on tomato in controlled environment in order to test the response of two long-time storage cultivars to PRD. Ponderosa tomato, a cultivar with yellow fruits, was compared to Giallo tondo di Auletta, a local cultivar from southern Campania (Italy. Plants were subjected to three irrigation treatments: plants receiving an amount of water equivalent to 100% of plant evapotranspiration (V100; plants in which 50% of the amount of water given to V100 was supplied (V50; and plants where one root compartment was irrigated at 50% of water requirements and the other compartment was allowed to dry, and thereafter every side was rewetted alternatively (PRD. The highest levels of leaf abscisic acid (ABA [on average equal to 104 ng g–1 fresh weight FW] were measured in PRD and V50, at 70 days after transplantation. Root ABA concentration in both PRD and V50 reached mean values of 149 ng g–1 FW. There were differences for the irrigation regime in root ABA biosynthesis and accumulation under partial root-zone drying and conventional deficit irrigation (V50. Assimilation rate, stomatal conductance and intercellular CO2 concentration decreased in relation to the irrigation regime by 22, 36 and 12%, respectively, in PRD, V50 and V100 at 50 days after transplantation. Ponderosa variety accumulated 20% more dry matter than Auletta and significant differences were observed in leaf area. In both PRD and V50 of the two varieties, it was possible to save on average 46% of water. Our results indicate that there is still space to optimise the PRD strategy, to further improve the cumulative physiological effects of the root-sourced signaling system.

  13. Auxin and cytokinin metabolism and root morphological modifications in Arabidopsis thaliana seedlings infected with Cucumber mosaic virus (CMV) or exposed to cadmium.

    Science.gov (United States)

    Vitti, Antonella; Nuzzaci, Maria; Scopa, Antonio; Tataranni, Giuseppe; Remans, Tony; Vangronsveld, Jaco; Sofo, Adriano

    2013-03-26

    Arabidopsis thaliana L. is a model plant but little information is available about morphological root changes as part of a phytohormonal common response against both biotic and abiotic stressors. For this purpose, two-week-old Arabidopsis seedlings were treated with 10 µM CdSO4 or infected with CMV. After 12 days the entire aerial parts and the root system were analyzed, and the presence of CMV or the accumulation of Cd were detected. Microscopic analysis revealed that both CMV and Cd influenced root morphology by a marked development in the length of root hairs and an intense root branching if compared to controls. Among the three treatments, Cd-treated seedlings showed a shorter root axis length and doubled their lateral root diameter, while the lateral roots of CMV-infected seedlings were the longest. The root growth patterns were accompanied by significant changes in the levels of indole-3-acetic acid, trans-zeatin riboside, dihydrozeatin riboside, as a probable consequence of the regulation of some genes involved in their biosynthesis/degradation. The opposite role on root development played by the phythormones studied is discussed in detail. The results obtained could provide insights into novel strategies for plant defense against pathogens and plant protection against pollutants.

  14. Final Report on Regulation of Guaiacyl and Syringyl Monolignol Biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Vincent L. Chiang

    2006-03-09

    The focus of this research is to understand syringyl monolignol biosynthesis that leads to the formation of syringyl lignin, a type of lignin that can be easily removed during biomass conversion. We have achieved the three originally proposed goals for this project. (1) SAD and CAD genes (enzyme catalytic and kinetic properties) and their functional relevance to CAld5H/AldOMT pathway, (2) spatiotemporal expression patterns of Cald5H, AldOMT, SAD and CAD genes, and (3) functions of CAld5H, AldOMT, and SAD genes in vivo using transgenic aspen. Furthermore, we also found that microRNA might be involved in the upstream regulatory network of lignin biosynthesis and wood formation. The achievements are as below. (1) Based on biochemical and molecular studies, we discovered a novel syringyl-specific alcohol dehydrogenase (SAD) involved in monolignol biosynthesis in angiosperm trees. Through CAld5H/OMT/SAD mediation, syringyl monolignol biosynthesis branches out from guaiacyl pathway at coniferaldehyde; (2) The function of CAld5H gene in this syringyl monolignol biosynthesis pathway also was confirmed in vivo in transgenic Populus; (3) The proposed major monolignol biosynthesis pathways were further supported by the involving biochemical functions of CCR based on a detailed kinetic study; (4) Gene promoter activity analysis also supported the cell-type specific expression of SAD and CAD genes in xylem tissue, consistent with the cell-specific locations of SAD and CAD proteins and with the proposed pathways; (5) We have developed a novel small interfering RNA (siRNA)-mediated stable gene-silencing system in transgenic plants; (6) Using the siRNA and P. trichocarpa transformation/regeneration systems we are currently producing transgenic P. trichocarpa to investigate the interactive functions of CAD and SAD in regulating guaiacyl and syringyl lignin biosynthesis; (7) We have cloned for the first time from a tree species, P. trichocarpa, small regulatory RNAs termed micro

  15. Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

    Directory of Open Access Journals (Sweden)

    Franziska Hemmerling

    2016-07-01

    Full Text Available This review highlights the biosynthesis of heterocycles in polyketide natural products with a focus on oxygen and nitrogen-containing heterocycles with ring sizes between 3 and 6 atoms. Heterocycles are abundant structural elements of natural products from all classes and they often contribute significantly to their biological activity. Progress in recent years has led to a much better understanding of their biosynthesis. In this context, plenty of novel enzymology has been discovered, suggesting that these pathways are an attractive target for future studies.

  16. Topical problems in the biosynthesis of red blood pigment

    International Nuclear Information System (INIS)

    Franck, B.

    1982-01-01

    Uroporphyrinogen III plays a key role in the biosynthesis of heme, the red pigment of blood. In vivo studies with specifically 14 C- and 3 H-labeled precursors have revealed that the formation of uroporphyrinogen III in the organism follows several primary and subsidiary pathways. Model experiments on the pattern of biosynthesis have led to simple and effective methods of synthesizing uroporphyrin analogs and have shwon that their production is strongly favored thermodynamically, The biologically important porphyrins thus available permit a mechanistic explanantion of the light-induced dermatoses in porphyria diseases and suggest promising medical applications in diagnosis and therapy. (orig.)

  17. Carbon extension in peptidylnucleoside biosynthesis by radical-SAM enzymes

    Science.gov (United States)

    Lilla, Edward A.; Yokoyama, Kenichi

    2016-01-01

    Nikkomycins and polyoxins are antifungal peptidylnucleoside (PN) antibiotics active against human and plant pathogens. Here, we report that during PN biosynthesis in Streptomyces cacaoi and Streptomyces tendae, the C5′-extension of the nucleoside essential for downstream structural diversification is catalyzed by a conserved radical S-adenosyl-L-methionine (SAM) enzyme, PolH or NikJ. This is distinct from the nucleophilic mechanism reported for antibacterial nucleosides and represents a novel mechanism of nucleoside natural product biosynthesis. PMID:27642865

  18. Phosphoribosyl Diphosphate (PRPP): Biosynthesis, Enzymology, Utilization, and Metabolic Significance

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; Andersen, Kasper R; Kilstrup, Mogens

    2017-01-01

    . PRPP is utilized in the biosynthesis of purine and pyrimidine nucleotides, the amino acids histidine and tryptophan, the cofactors NAD and tetrahydromethanopterin, arabinosyl monophosphodecaprenol, and certain aminoglycoside antibiotics. The participation of PRPP in each of these metabolic pathways...... analysis. PRPP, furthermore, is an effector molecule of purine and pyrimidine nucleotide biosynthesis, either by binding to PurR or PyrR regulatory proteins or as an allosteric activator of carbamoylphosphate synthetase. Genetic analyses have disclosed a number of mutants altered in the PRPP synthase...

  19. [Biosynthesis of benzoisochromanequinones antibiotics from streptomycetes--a review].

    Science.gov (United States)

    Wang, Wei; Wang, Huili; Li, Aiying

    2012-05-04

    Benzoisochromanequinones antibiotics, a group of bioactive polyketide compounds with aromatic polyketide skeletal cores, are accumulated in streptomycetes. The biosynthesis of benzoisochromanequinones antibiotics has triggered great interest because they not only represent model biosynthetic mechanisms of aromatic polyketide skeletal structures, but also possess a variety of tailoring modifications rendering them highly structural and bioactive diversity. Here we reviewed important advances in biosynthesis of benzoisochromanequinones antibiotics in recent 25 years with focusing on the modification mechanisms of these compounds and on the prospects of the metabolic engineering and pharmaceutical discovery of benzoisochromanequinones antibiotics.

  20. Structure, Biosynthesis, and Occurrence of Bacterial Pyrrolizidine Alkaloids.

    Science.gov (United States)

    Schimming, Olivia; Challinor, Victoria L; Tobias, Nicholas J; Adihou, Hélène; Grün, Peter; Pöschel, Laura; Richter, Christian; Schwalbe, Harald; Bode, Helge B

    2015-10-19

    Pyrrolizidine alkaloids (PAs) are widespread plant natural products with potent toxicity and bioactivity. Herein, the identification of bacterial PAs from entomopathogenic bacteria using differential analysis by 2D NMR spectroscopy (DANS) and mass spectrometry is described. Their biosynthesis was elucidated to involve a non-ribosomal peptide synthetase. The occurrence of these biosynthesis gene clusters in Gram-negative and Gram-positive bacteria indicates an important biological function in bacteria. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Root anatomical phenes predict root penetration ability and biomechanical properties in maize (Zea Mays)

    OpenAIRE

    Chimungu, Joseph G.; Loades, Kenneth W.; Lynch, Jonathan P.

    2015-01-01

    The ability of roots to penetrate hard soil is important for crop productivity but specific root phenes contributing to this ability are poorly understood. Root penetrability and biomechanical properties are likely to vary in the root system dependent on anatomical structure. No information is available to date on the influence of root anatomical phenes on root penetrability and biomechanics. Root penetration ability was evaluated using a wax layer system. Root tensile and bending strength we...

  2. Nicotinamide adenine dinucleotide biosynthesis promotes liver regeneration.

    Science.gov (United States)

    Mukherjee, Sarmistha; Chellappa, Karthikeyani; Moffitt, Andrea; Ndungu, Joan; Dellinger, Ryan W; Davis, James G; Agarwal, Beamon; Baur, Joseph A

    2017-02-01

    The regenerative capacity of the liver is essential for recovery from surgical resection or injuries induced by trauma or toxins. During liver regeneration, the concentration of nicotinamide adenine dinucleotide (NAD) falls, at least in part due to metabolic competition for precursors. To test whether NAD availability restricts the rate of liver regeneration, we supplied nicotinamide riboside (NR), an NAD precursor, in the drinking water of mice subjected to partial hepatectomy. NR increased DNA synthesis, mitotic index, and mass restoration in the regenerating livers. Intriguingly, NR also ameliorated the steatosis that normally accompanies liver regeneration. To distinguish the role of hepatocyte NAD levels from any systemic effects of NR, we generated mice overexpressing nicotinamide phosphoribosyltransferase, a rate-limiting enzyme for NAD synthesis, specifically in the liver. Nicotinamide phosphoribosyltransferase overexpressing mice were mildly hyperglycemic at baseline and, similar to mice treated with NR, exhibited enhanced liver regeneration and reduced steatosis following partial hepatectomy. Conversely, mice lacking nicotinamide phosphoribosyltransferase in hepatocytes exhibited impaired regenerative capacity that was completely rescued by administering NR. NAD availability is limiting during liver regeneration, and supplementation with precursors such as NR may be therapeutic in settings of acute liver injury. (Hepatology 2017;65:616-630). © 2016 by the American Association for the Study of Liver Diseases.

  3. Root development during soil genesis: effects of root-root interactions, mycorrhizae, and substrate

    Science.gov (United States)

    Salinas, A.; Zaharescu, D. G.

    2015-12-01

    A major driver of soil formation is the colonization and transformation of rock by plants and associated microbiota. In turn, substrate chemical composition can also influence the capacity for plant colonization and development. In order to better define these relationships, a mesocosm study was set up to analyze the effect mycorrhizal fungi, plant density and rock have on root development, and to determine the effect of root morphology on weathering and soil formation. We hypothesized that plant-plant and plant-fungi interactions have a stronger influence on root architecture and rock weathering than the substrate composition alone. Buffalo grass (Bouteloua dactyloides) was grown in a controlled environment in columns filled with either granular granite, schist, rhyolite or basalt. Each substrate was given two different treatments, including grass-microbes and grass-microbes-mycorrhizae and incubated for 120, 240, and 480 days. Columns were then extracted and analyzed for root morphology, fine fraction, and pore water major element content. Preliminary results showed that plants produced more biomass in rhyolite, followed by schist, basalt, and granite, indicating that substrate composition is an important driver of root development. In support of our hypothesis, mycorrhizae was a strong driver of root development by stimulating length growth, biomass production, and branching. However, average root length and branching also appeared to decrease in response to high plant density, though this trend was only present among roots with mycorrhizal fungi. Interestingly, fine fraction production was negatively correlated with average root thickness and volume. There is also slight evidence indicating that fine fraction production is more related to substrate composition than root morphology, though this data needs to be further analyzed. Our hope is that the results of this study can one day be applied to agricultural research in order to promote the production of crops

  4. Non-canonical WOX11-mediated root branching contributes to plasticity in arabidopsis root system architecture

    NARCIS (Netherlands)

    Sheng, Lihong; Hu, Xiaomei; Du, Yujuan; Zhang, Guifang; Huang, Hai; Scheres, Ben; Xu, Lin

    2017-01-01

    Lateral roots (LRs), which originate from the growing root, and adventitious roots (ARs), which are formed from non-root organs, are the main contributors to the post-embryonic root system in Arabidopsis. However, our knowledge of how formation of the root system is altered in response to diverse

  5. Molecular diagnosis of Phytophthora cinnamomi associated with root rot in avocado producing areas of Ecuador

    Directory of Open Access Journals (Sweden)

    Diana Elizabeth Toapanta-Gallegos

    2017-05-01

    Full Text Available One of the most damaging diseases in cultivation of avocado (Persea americana Mill. is root rot associated with Phytophthora cinnamomi Rands. This disease causes progressive wilt and even death of the tree. The objective of this study was to identify the presence of P. cinnamomi in two productive areas of avocado in Ecuador using the molecular technique PCR-RFLP. Tree root samples were obtained with root rot symptoms in the production areas, from which 10 isolates were morphologically identified with Phytophthora spp. infection. To distinguish among the various Phytophthora species, a molecular analysis was performed using molecular markers in the ITSregion of the ribosomal DNA (rDNA. The ITSdigestion fragment obtained by PCR with the Ta qI enzyme confirmed the presence of Phytophthora cinnamomi in the isolated samples, and its association with root rot in the sampled production areas.

  6. Calcium ion dependency of ethylene production in segments of primary roots of Zea mays

    Science.gov (United States)

    Hasenstein, K. H.; Evans, M. L.

    1986-01-01

    We investigated the effect of Ca2+ on ethylene production in 2-cm long apical segments from primary roots of corn (Zea mays L., B73 x Missouri 17) seedlings. The seedlings were raised under different conditions of Ca2+ availability. Low-Ca and high-Ca seedlings were raised by soaking the grains and watering the seedlings with distilled water or 10 mM CaCl2, respectively. Segments from high-Ca roots produced more than twice as much ethylene as segments from low-Ca roots. Indoleacetic acid (IAA; 1 micromole) enhanced ethylene production in segments from both low-Ca and high-Ca roots but auxin-induced promotion of ethylene production was consistently higher in segments from high-Ca roots. Addition of 1-aminocyclopropane-1-carboxylic acid (ACC) to root segments from low-Ca seedlings doubled total ethylene production and the rate of production remained fairly constant during a 24 h period of monitoring. In segments from high-Ca seedlings ACC also increased total ethylene production but most of the ethylene was produced within the first 6 h. The data suggest that Ca2+ enhances the conversion of ACC to ethylene. The terminal 2 mm of the root tip were found to be especially important to ethylene biosynthesis by apical segments and, experiments using 45Ca2+ as tracer indicated that the apical 2 mm of the root is the region of strongest Ca2+ accumulation. Other cations such as Mn2+, Mg2+, and K+ could largely substitute for Ca2+. The significance of these findings is discussed with respect to recent evidence for gravity-induced Ca2+ redistribution and its relationship to the establishment of asymmetric growth during gravitropic curvature.

  7. Hypocotyl adventitious root organogenesis differs from lateral root development.

    Science.gov (United States)

    Verstraeten, Inge; Schotte, Sébastien; Geelen, Danny

    2014-01-01

    Wound-induced adventitious root (AR) formation is a requirement for plant survival upon root damage inflicted by pathogen attack, but also during the regeneration of plant stem cuttings for clonal propagation of elite plant varieties. Yet, adventitious rooting also takes place without wounding. This happens for example in etiolated Arabidopsis thaliana hypocotyls, in which AR initiate upon de-etiolation or in tomato seedlings, in which AR initiate upon flooding or high water availability. In the hypocotyl AR originate from a cell layer reminiscent to the pericycle in the primary root (PR) and the initiated AR share histological and developmental characteristics with lateral roots (LRs). In contrast to the PR however, the hypocotyl is a determinate structure with an established final number of cells. This points to differences between the induction of hypocotyl AR and LR on the PR, as the latter grows indeterminately. The induction of AR on the hypocotyl takes place in environmental conditions that differ from those that control LR formation. Hence, AR formation depends on differentially regulated gene products. Similarly to AR induction in stem cuttings, the capacity to induce hypocotyl AR is genotype-dependent and the plant growth regulator auxin is a key regulator controlling the rooting response. The hormones cytokinins, ethylene, jasmonic acid, and strigolactones in general reduce the root-inducing capacity. The involvement of this many regulators indicates that a tight control and fine-tuning of the initiation and emergence of AR exists. Recently, several genetic factors, specific to hypocotyl adventitious rooting in A. thaliana, have been uncovered. These factors reveal a dedicated signaling network that drives AR formation in the Arabidopsis hypocotyl. Here we provide an overview of the environmental and genetic factors controlling hypocotyl-born AR and we summarize how AR formation and the regulating factors of this organogenesis are distinct from LR

  8. Hypocotyl adventitious root organogenesis differs from lateral root development

    Directory of Open Access Journals (Sweden)

    Inge eVerstraeten

    2014-09-01

    Full Text Available Wound-induced adventitious root (AR formation is a requirement for plant survival upon root damage inflicted by pathogen attack, but also during the regeneration of plant stem cuttings for clonal propagation of elite plant varieties. Yet, adventitious rooting also takes place without wounding. This happens for example in etiolated Arabidopsis thaliana hypocotyls, in which AR initiate upon de-etiolation or in tomato seedlings, in which AR initiate upon flooding or high water availability. In the hypocotyl AR originate from a cell layer reminiscent to the pericycle in the primary root (PR and the initiated AR share histological and developmental characteristics with lateral roots (LR. In contrast to the PR however, the hypocotyl is a determinate structure with an established final number of cells. This points to differences between the induction of hypocotyl AR and LR on the PR, as the latter grows indeterminately. The induction of AR on the hypocotyl takes place in environmental conditions that differ from those that control LR formation. Hence, AR formation depends on differentially regulated gene products. Similarly to AR induction in stem cuttings, the capacity to induce hypocotyl AR is genotype-dependent and the plant growth regulator auxin is a key regulator controlling the rooting response. The hormones cytokinins, ethylene, jasmonic acid and strigolactones in general reduce the root-inducing capacity. The involvement of this many regulators indicates that a tight control and fine-tuning of the initiation and emergence of AR exists. Recently, several genetic factors, specific to hypocotyl adventitious rooting in Arabidopsis thaliana, have been uncovered. These factors reveal a dedicated signaling network that drives AR formation in the Arabidopsis hypocotyl. Here we provide an overview of the environmental and genetic factors controlling hypocotyl-born AR and we summarize how AR formation and the regulating factors of this organogenesis are

  9. Siderophore biosynthesis coordinately modulated the virulence-associated interactive metabolome of uropathogenic Escherichia coli and human urine.

    Science.gov (United States)

    Su, Qiao; Guan, Tianbing; Lv, Haitao

    2016-04-14

    Uropathogenic Escherichia coli (UPEC) growth in women's bladders during urinary tract infection (UTI) incurs substantial chemical exchange, termed the "interactive metabolome", which primarily accounts for the metabolic costs (utilized metabolome) and metabolic donations (excreted metabolome) between UPEC and human urine. Here, we attempted to identify the individualized interactive metabolome between UPEC and human urine. We were able to distinguish UPEC from non-UPEC by employing a combination of metabolomics and genetics. Our results revealed that the interactive metabolome between UPEC and human urine was markedly different from that between non-UPEC and human urine, and that UPEC triggered much stronger perturbations in the interactive metabolome in human urine. Furthermore, siderophore biosynthesis coordinately modulated the individualized interactive metabolome, which we found to be a critical component of UPEC virulence. The individualized virulence-associated interactive metabolome contained 31 different metabolites and 17 central metabolic pathways that were annotated to host these different metabolites, including energetic metabolism, amino acid metabolism, and gut microbe metabolism. Changes in the activities of these pathways mechanistically pinpointed the virulent capability of siderophore biosynthesis. Together, our findings provide novel insights into UPEC virulence, and we propose that siderophores are potential targets for further discovery of drugs to treat UPEC-induced UTI.

  10. Effects of ethylene on the kinetics of curvature and auxin redistribution in gravistimulated roots of Zea mays

    Science.gov (United States)

    Lee, J. S.; Evans, M. L.

    1990-01-01

    We tested the involvement of ethylene in maize (Zea mays L.) root gravitropism by measuring the kinetics of curvature and lateral auxin movement in roots treated with ethylene, inhibitors of ethylene synthesis, or inhibitors of ethylene action. In the presence of ethylene the latent period of gravitropic curvature appeared to be increased somewhat. However, ethylene-treated roots continued to curve after control roots had reached their final angle of curvature. Consequently, maximum curvature in the presence of ethylene was much greater in ethylene-treated roots than in controls. Inhibitors of ethylene biosynthesis or action had effects on the kinetics of curvature opposite to that of ethylene, i.e. the latent period appeared to be shortened somewhat while total curvature was reduced relative to that of controls. Label from applied 3H-indole-3-acetic acid was preferentially transported toward the lower side of stimulated roots. In parallel with effects on curvature, ethylene treatment delayed the development of gravity-induced asymmetric auxin movement across the root but extended its duration once initiated. The auxin transport inhibitor, 1-N-naphthylphthalamic acid reduced both gravitropic curvature and the effect of ethylene on curvature. Since neither ethylene nor inhibitors of ethylene biosynthesis or action prevented curvature, we conclude that ethylene does not mediate the primary differential growth response causing curvature. Because ethylene affects curvature and auxin transport in parallel, we suggest that ethylene modifies curvature by affecting gravity-induced lateral transport of auxin, perhaps by interfering with adaptation of the auxin transport system to the gravistimulus.

  11. 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.

  12. Distinguishing Failure to Cure From Complication After Penile Prosthesis Implantation.

    Science.gov (United States)

    Pineda, Miguel; Burnett, Arthur L

    2017-05-01

    A successful penile prosthesis implantation (PPI) surgery can be defined by outcomes beyond the absence of complications. To introduce the concept of failure to cure (FTC) in the context of PPI to more accurately gauge postoperative outcomes after PPI. Consecutive patients from our sexual function registry who underwent PPI from January 2011 to December 2013 were analyzed. Demographics, previous treatment of erectile dysfunction, comorbidities, social history, postoperative problems (POPs), and surgical outcomes were tabulated. Patients completed the International Index of Erection Function (IIEF) and the Erectile Dysfunction Inventory of Treatment Satisfaction questionnaires. We defined a complication, according to the Clavien-Dindo classification, as any deviation from the ideal postoperative course that is not inherent in the procedure and does not constitute an FTC. FTC was defined as a POP that was not a complication. The χ 2 tests, t-tests, or Wilcoxon rank-sum tests were used. Patient-reported and objective outcomes after PPI. Our enrollment consisted of 185 patients, and we contacted 124 (67%). Of these, 16 (12.9%) had a POP requiring reoperation. Eight patients developed surgical complications (three infections, four erosions, and one chronic pain). Eight patients had FTC (four malpositions and four malfunctions). Factors that correlated with POPs were previous PPI, body mass index higher than 30 kg/m 2 , and previous treatment with intracorporal injections (P .05 for all comparisons). POPs after PPI surgery can be more accurately categorized using the Clavien-Dindo classification of surgical complications to more clearly distinguish surgical complications from FTC. Limitations of our study include its retrospective approach. Our series included a large proportion of patients treated for prostate cancer, which limits the generalizability of our findings. We also had a relatively short median follow-up time of 27 months. Patient-reported outcome

  13. IAA transport in corn roots includes the root cap

    International Nuclear Information System (INIS)

    Hasenstein, K.H.

    1989-01-01

    In earlier reports we concluded that auxin is the growth regulator that controls gravicurvature in roots and that the redistribution of auxin occurs within the root cap. Since other reports did not detect auxin in the root cap, we attempted to confirm the IAA does move through the cap. Agar blocks containing 3 H-IAA were applied to the cut surface of 5 mm long apical segments of primary roots of corn (mo17xB73). After 30 to 120 min radioactivity (RA) of the cap and root tissue was determined. While segments suspended in water-saturated air accumulated very little RA in the cap, application of 0.5 μ1 of dist. water to the cap (=controls) increased RA of the cap dramatically. Application to the cap of 0.5 μ1 of sorbitol or the Ca 2+ chelator EGTA reduced cap RA to 46% and 70% respectively compared to water, without affecting uptake. Control root segments gravireacted faster than non-treated or osmoticum or EGTA treated segments. The data indicate that both the degree of hydration and calcium control the amount of auxin moving through the cap

  14. Biosynthesis of allene oxides in Physcomitrella patens

    Directory of Open Access Journals (Sweden)

    Scholz Julia

    2012-11-01

    Full Text Available Abstract Background The moss Physcomitrella patens contains C18- as well as C20-polyunsaturated fatty acids that can be metabolized by different enzymes to form oxylipins such as the cyclopentenone cis(+-12-oxo phytodienoic acid. Mutants defective in the biosynthesis of cyclopentenones showed reduced fertility, aberrant sporophyte morphology and interrupted sporogenesis. The initial step in this biosynthetic route is the conversion of a fatty acid hydroperoxide to an allene oxide. This reaction is catalyzed by allene oxide synthase (AOS belonging as hydroperoxide lyase (HPL to the cytochrome P450 family Cyp74. In this study we characterized two AOS from P. patens, PpAOS1 and PpAOS2. Results Our results show that PpAOS1 is highly active with both C18 and C20-hydroperoxy-fatty acid substrates, whereas PpAOS2 is fully active only with C20-substrates, exhibiting trace activity (~1000-fold lower kcat/KM with C18 substrates. Analysis of products of PpAOS1 and PpHPL further demonstrated that both enzymes have an inherent side activity mirroring the close inter-connection of AOS and HPL catalysis. By employing site directed mutagenesis we provide evidence that single amino acid residues in the active site are also determining the catalytic activity of a 9-/13-AOS – a finding that previously has only been reported for substrate specific 13-AOS. However, PpHPL cannot be converted into an AOS by exchanging the same determinant. Localization studies using YFP-labeled AOS showed that PpAOS2 is localized in the plastid while PpAOS1 may be found in the cytosol. Analysis of the wound-induced cis(+-12-oxo phytodienoic acid accumulation in PpAOS1 and PpAOS2 single knock-out mutants showed that disruption of PpAOS1, in contrast to PpAOS2, results in a significantly decreased cis(+-12-oxo phytodienoic acid formation. However, the knock-out mutants of neither PpAOS1 nor PpAOS2 showed reduced fertility, aberrant sporophyte morphology or interrupted sporogenesis

  15. Auxin-Induced Ethylene Triggers Abscisic Acid Biosynthesis and Growth Inhibition1

    Science.gov (United States)

    Hansen, Hauke; Grossmann, Klaus

    2000-01-01

    The growth-inhibiting effects of indole-3-acetic acid (IAA) at high concentration and the synthetic auxins 7-chloro-3-methyl-8-quinolinecarboxylic acid (quinmerac), 2-methoxy-3,6-dichlorobenzoic acid (dicamba), 4-amino-3,6,6-trichloropicolinic acid (picloram), and naphthalene acetic acid, were investigated in cleavers (Galium aparine). When plants were root treated with 0.5 mm IAA, shoot epinasty and inhibition of root and shoot growth developed during 24 h. Concomitantly, 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activity, and ACC and ethylene production were transiently stimulated in the shoot tissue within 2 h, followed by increases in immunoreactive (+)-abscisic acid (ABA) and its precursor xanthoxal (xanthoxin) after 5 h. After 24 h of treatment, levels of xanthoxal and ABA were elevated up to 2- and 24-fold, relative to control, respectively. In plants treated with IAA, 7-chloro-3-methyl-8-quinolinecarboxylic acid, naphthalene acetic acid, 2-methoxy-3,6-dichlorobenzoic acid, and 4-amino-3,6,6-trichloropicolinic acid, levels of ethylene, ACC, and ABA increased in close correlation with inhibition of shoot growth. Aminoethoxyvinyl-glycine and cobalt ions, which inhibit ethylene synthesis, decreased ABA accumulation and growth inhibition, whereas the ethylene-releasing ethephon promoted ABA levels and growth inhibition. In accordance, tomato mutants defective in ethylene perception (never ripe) did not produce the xanthoxal and ABA increases and growth inhibition induced by auxins in wild-type plants. This suggests that auxin-stimulated ethylene triggers ABA accumulation and the consequent growth inhibition. Reduced catabolism most probably did not contribute to ABA increase, as indicated by immunoanalyses of ABA degradation and conjugation products in shoot tissue and by pulse experiments with [3H]-ABA in cell suspensions of G. aparine. In contrast, studies using inhibitors of ABA biosynthesis (fluridone, naproxen, and tungstate), ABA

  16. Tetraploid Rangpur lime rootstock increases drought tolerance via enhanced constitutive root abscisic acid production.

    Science.gov (United States)

    Allario, Thierry; Brumos, Javier; Colmenero-Flores, Jose M; Iglesias, Domingo J; Pina, Jose A; Navarro, Luis; Talon, Manuel; Ollitrault, Patrick; Morillon, Raphaël

    2013-04-01

    Whole-genome duplication, or polyploidy, is common in many plant species and often leads to better adaptation to adverse environmental condition. However, little is known about the physiological and molecular determinants underlying adaptation. We examined the drought tolerance in diploid (2x) and autotetraploid (4x) clones of Rangpur lime (Citrus limonia) rootstocks grafted with 2x Valencia Delta sweet orange (Citrus sinensis) scions, named V/2xRL and V/4xRL, respectively. Physiological experiments to study root-shoot communication associated with gene expression studies in roots and leaves were performed. V/4xRL was much more tolerant to water deficit than V/2xRL. Gene expression analysis in leaves and roots showed that more genes related to the response to water stress were differentially expressed in V/2xRL than in V/4xRL. Prior to the stress, when comparing V/4xRL to V/2xRL, V/4xRL leaves had lower stomatal conductance and greater abscisic acid (ABA) content. In roots, ABA content was higher in V/4xRL and was associated to a greater expression of drought responsive genes, including CsNCED1, a pivotal regulatory gene of ABA biosynthesis. We conclude that tetraploidy modifies the expression of genes in Rangpur lime citrus roots to regulate long-distance ABA signalling and adaptation to stress. © 2012 Blackwell Publishing Ltd.

  17. Genetic basis of coaggregation receptor polysaccharide biosynthesis in Streptococcus sanguinis and related species.

    Science.gov (United States)

    Yang, J; Yoshida, Y; Cisar, J O

    2014-02-01

    Interbacterial adhesion between streptococci and actinomyces promotes early dental plaque biofilm development. Recognition of coaggregation receptor polysaccharides (RPS) on strains of Streptococcus sanguinis, Streptococcus gordonii and Streptococcus oralis by Actinomyces spp. type 2 fimbriae is the principal mechanism of these interactions. Previous studies of genetic loci for synthesis of RPS (rps) and RPS precursors (rml, galE1 and galE2) in S. gordonii 38 and S. oralis 34 revealed differences between these strains. To determine whether these differences are strain-specific or species-specific, we identified and compared loci for polysaccharide biosynthesis in additional strains of these species and in several strains of the previously unstudied species, S. sanguinis. Genes for synthesis of RPS precursors distinguished the rps loci of different streptococci. Hence, rml genes for synthesis of TDP-L-Rha were in rps loci of S. oralis strains but at other loci in S. gordonii and S. sanguinis. Genes for two distinct galactose epimerases were also distributed differently. Hence, galE1 for epimerization of UDP-Glc and UDP-Gal was in galactose operons of S. gordonii and S. sanguinis strains but surprisingly, this gene was not present in S. oralis. Moreover, galE2 for epimerization of both UDP-Glc and UDP-Gal and UDP-GlcNAc and UDP-GalNAc was at a different locus in each species, including rps operons of S. sanguinis. The findings provide insight into cell surface properties that distinguish different RPS-producing streptococci and open an approach for identifying these bacteria based on the arrangement of genes for synthesis of polysaccharide precursors. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  18. Charles L. Brewer Award for Distinguished Teaching of Psychology: Neil Lutsky

    Science.gov (United States)

    American Psychologist, 2011

    2011-01-01

    The American Psychological Foundation (APF) Charles L. Brewer Award for Distinguished Teaching of Psychology recognizes an outstanding career contribution to the teaching of psychology. The 2011 recipient of the Distinguished Teaching Award is Neil Lutsky. Dorothy W. Cantor, president of the APF, will present the APF Distinguished Teaching Award…

  19. Research leadership: should clinical directors be distinguished researchers?

    Science.gov (United States)

    Allison, Stephen; Goodall, Amanda H; Bastiampillai, Tarun

    2016-06-01

    Clinical directors established research-led healthcare by combining research, teaching and clinical excellence within the teaching hospitals. This research culture created high clinical standards, which benefited patients, the workforce and healthcare organisations. The current paper explores this research leadership role for clinical directors. It reviews studies arising from the theory of expert leadership, which focuses on the relationship between a leader's core knowledge and organisational performance. More specifically, we examine the expert leader's research track record, the associations with their organisation's performance, and the influence of research activity on clinical excellence. Distinguished researchers still lead the most prestigious teaching hospitals and the most trusted departments of psychiatry in the United States where the clinical directorate structure originated. It is also known that good scholars can improve research output when appointed to leadership positions. This suggests that the clinical director's research track record should be a consideration at a time when research is being embedded in Australia's local health networks. A clinical director's leadership may influence the research performance of their department and contribute to the quality of mental healthcare. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  20. Distinguishing human cell types based on housekeeping gene signatures.

    Science.gov (United States)

    Oyolu, Chuba; Zakharia, Fouad; Baker, Julie

    2012-03-01

    'In this report, we use single cell gene expression to identify transcriptional patterns emerging during the differentiation of human embryonic stem cells (hESCs) into the endodermal lineage. Endoderm-specific transcripts are highly variable between individual CXCR4(+) endodermal cells, suggesting that either the cells generated from in vitro differentiation are distinct or that these embryonic cells tolerate a high degree of transcript variability. Housekeeping transcripts, on the other hand, are far more consistently expressed within the same cellular population. However, when we compare the levels of housekeeping transcripts between hESCs and derived endoderm, patterns emerge that can be used to clearly separate the two embryonic cell types. We further compared four additional human cell types, including 293T, induced pluripotent stem cell (iPSC), HepG2, and endoderm-derived iPSC. In each case, the relative levels of housekeeping transcripts defined a particular cell fate. Interestingly, we find that three transcripts, LDHA, NONO, and ACTB, contribute the most to this diversity and together serve to segregate all six cell types. Overall, this suggests that levels of housekeeping transcripts, which are expressed within all cells, can be leveraged to distinguish between human cell types and thus may serve as important biomarkers for stem cell biology and other disciplines. Copyright © 2011 AlphaMed Press.