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Sample records for thaliana constitutively expressing

  1. Constitutive non-inducible expression of the Arabidopsis thaliana Nia 2 gene in two nitrate reductase mutants of Nicotiana plumbaginifolia.

    Science.gov (United States)

    Kaye, C; Crawford, N M; Malmberg, R L

    1997-04-01

    We have isolated a haploid cell line of N. plumbaginifolia, hNP 588, that is constitutive and not inducible for nitrate reductase. Nitrate reductase mutants were isolated from hNP 588 protoplasts upon UV irradiation. Two of these nitrate reductase-deficient cell lines, nia 3 and nia 25, neither of which contained any detectable nitrate reductase activity, were selected for complementation studies. A cloned Arabidopsis thaliana nitrate reductase gene Nia 2 was introduced into each of the two mutants resulting in 56 independent kanamycin-resistant cell lines. Thirty of the 56 kanamycin-resistant cell lines were able to grow on nitrate as the sole nitrogen source. Eight of these were further analyzed for nitrate reductase enzyme activity and nitrate reductase mRNA production. All eight lines had detectable nitrate reductase activity ranging from 7% to 150% of wild-type hNP 588 callus. The enzyme activity levels were not influenced by the nitrogen source in the medium. The eight lines examined expressed a constitutive, non-inducible 3.2 kb mRNA species that was not present in untransformed controls.

  2. Constitutive expression of a salinity-induced wheat WRKY transcription factor enhances salinity and ionic stress tolerance in transgenic Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yuxiang, E-mail: yuxiangqin@126.com [Department of Biotechnology, University of Jinan, Jinan 250022 (China); Tian, Yanchen [The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan 250100 (China); Han, Lu; Yang, Xinchao [Department of Biotechnology, University of Jinan, Jinan 250022 (China)

    2013-11-15

    Highlights: •A class II WRKY transcription factor, TaWRKY79 was isolated and characterized. •TaWRKY79 was induced by NaCl or abscisic acid. •843 bp regulatory segment was sufficient to respond to ABA or NaCl treatment. •TaWRKY79 enhanced salinity and ionic tolerance while reduced sensitivity to ABA. •TaWRKY79 increased salinity and ionic tolerance in an ABA-dependent pathway. -- Abstract: The isolation and characterization of TaWRKY79, a wheat class II WRKY transcription factor, is described. Its 1297 bp coding region includes a 987 bp long open reading frame. TaWRKY79 was induced by stressing seedlings with either NaCl or abscisic acid (ABA). When a fusion between an 843 bp segment upstream of the TaWRKY79 coding sequence and GUS was introduced into Arabidopsis thaliana, GUS staining indicated that this upstream segment captured the sequence(s) required to respond to ABA or NaCl treatment. When TaWRKY79 was constitutively expressed as a transgene in A. thaliana, the transgenic plants showed an improved capacity to extend their primary root in the presence of either 100 mM NaCl, 10 mM LiCl or 2 μM ABA. The inference was that TaWRKY79 enhanced the level of tolerance to both salinity and ionic stress, while reducing the level of sensitivity to ABA. The ABA-related genes ABA1, ABA2 ABI1 and ABI5 were all up-regulated in the TaWRKY79 transgenic plants, suggesting that the transcription factor operates in an ABA-dependent pathway.

  3. Constitutive expression of a salinity-induced wheat WRKY transcription factor enhances salinity and ionic stress tolerance in transgenic Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Qin, Yuxiang; Tian, Yanchen; Han, Lu; Yang, Xinchao

    2013-01-01

    Highlights: •A class II WRKY transcription factor, TaWRKY79 was isolated and characterized. •TaWRKY79 was induced by NaCl or abscisic acid. •843 bp regulatory segment was sufficient to respond to ABA or NaCl treatment. •TaWRKY79 enhanced salinity and ionic tolerance while reduced sensitivity to ABA. •TaWRKY79 increased salinity and ionic tolerance in an ABA-dependent pathway. -- Abstract: The isolation and characterization of TaWRKY79, a wheat class II WRKY transcription factor, is described. Its 1297 bp coding region includes a 987 bp long open reading frame. TaWRKY79 was induced by stressing seedlings with either NaCl or abscisic acid (ABA). When a fusion between an 843 bp segment upstream of the TaWRKY79 coding sequence and GUS was introduced into Arabidopsis thaliana, GUS staining indicated that this upstream segment captured the sequence(s) required to respond to ABA or NaCl treatment. When TaWRKY79 was constitutively expressed as a transgene in A. thaliana, the transgenic plants showed an improved capacity to extend their primary root in the presence of either 100 mM NaCl, 10 mM LiCl or 2 μM ABA. The inference was that TaWRKY79 enhanced the level of tolerance to both salinity and ionic stress, while reducing the level of sensitivity to ABA. The ABA-related genes ABA1, ABA2 ABI1 and ABI5 were all up-regulated in the TaWRKY79 transgenic plants, suggesting that the transcription factor operates in an ABA-dependent pathway

  4. Water deficits and heat shock effects on photosynthesis of a transgenic Arabidopsis thaliana constitutively expressing ABP9, a bZIP transcription factor

    DEFF Research Database (Denmark)

    Zhang, Xia; Wollenweber, Bernd; Jiang, Dong

    2008-01-01

    The effects of water deficits (WD), heat shock (HS), and both (HSWD) on photosynthetic carbon- and light-use efficiencies together with leaf ABA content, pigment composition and expressions of stress- and light harvesting-responsive genes were investigated in ABP9 [ABA-responsive-element (ABRE...... transport rate (ETR) in 5P2 plants were depressed under optimal growth conditions (control) in relation to WT, they were enhanced under HS and HSWD. These results indicate that ABP9 transgenic plants are less susceptible to stress than the WT. In addition, the increased ABA contents in both WT and 5P2......, altered expression of stress-regulated or light harvesting-responsive genes was observed. Collectively, our results indicate that constitutive expression of ABP9 improves the photosynthetic capacity of plants under stress by adjusting photosynthetic pigment composition, dissipating excess light energy...

  5. Stochastic gene expression in Arabidopsis thaliana.

    Science.gov (United States)

    Araújo, Ilka Schultheiß; Pietsch, Jessica Magdalena; Keizer, Emma Mathilde; Greese, Bettina; Balkunde, Rachappa; Fleck, Christian; Hülskamp, Martin

    2017-12-14

    Although plant development is highly reproducible, some stochasticity exists. This developmental stochasticity may be caused by noisy gene expression. Here we analyze the fluctuation of protein expression in Arabidopsis thaliana. Using the photoconvertible KikGR marker, we show that the protein expressions of individual cells fluctuate over time. A dual reporter system was used to study extrinsic and intrinsic noise of marker gene expression. We report that extrinsic noise is higher than intrinsic noise and that extrinsic noise in stomata is clearly lower in comparison to several other tissues/cell types. Finally, we show that cells are coupled with respect to stochastic protein expression in young leaves, hypocotyls and roots but not in mature leaves. Our data indicate that stochasticity of gene expression can vary between tissues/cell types and that it can be coupled in a non-cell-autonomous manner.

  6. 50/50 Expressional Odds of Retention Signifies the Distinction between Retained Introns and Constitutively Spliced Introns in Arabidopsis thaliana

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    Rui Mao

    2017-10-01

    Full Text Available Intron retention, one of the most prevalent alternative splicing events in plants, can lead to introns retained in mature mRNAs. However, in comparison with constitutively spliced introns (CSIs, the relevantly distinguishable features for retained introns (RIs are still poorly understood. This work proposes a computational pipeline to discover novel RIs from multiple next-generation RNA sequencing (RNA-Seq datasets of Arabidopsis thaliana. Using this pipeline, we detected 3,472 novel RIs from 18 RNA-Seq datasets and re-confirmed 1,384 RIs which are currently annotated in the TAIR10 database. We also use the expression of intron-containing isoforms as a new feature in addition to the conventional features. Based on these features, RIs are highly distinguishable from CSIs by machine learning methods, especially when the expressional odds of retention (i.e., the expression ratio of the RI-containing isoforms relative to the isoforms without RIs for the same gene reaches to or larger than 50/50. In this case, the RIs and CSIs can be clearly separated by the Random Forest with an outstanding performance of 0.95 on AUC (the area under a receiver operating characteristics curve. The closely related characteristics to the RIs include the low strength of splice sites, high similarity with the flanking exon sequences, low occurrence percentage of YTRAY near the acceptor site, existence of putative intronic splicing silencers (ISSs, i.e., AG/GA-rich motifs and intronic splicing enhancers (ISEs, i.e., TTTT-containing motifs, and enrichment of Serine/Arginine-Rich (SR proteins and heterogeneous nuclear ribonucleoparticle proteins (hnRNPs.

  7. Human intrinsic factor expressed in the plant Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Fedosov, Sergey N; Laursen, Niels B; Nexø, Ebba

    2003-01-01

    and contamination by other B12 binders. We tested the use of recombinant plants for large-scale production of pathogen-free human recombinant IF. Human IF was successfully expressed in the recombinant plant Arabidopsis thaliana. Extract from fresh plants possessed high B12-binding capacity corresponding to 70 mg...... to recombinant IF and gastric IF were alike, as was the interaction of recombinant and native IF with the specific receptor cubilin. The data presented show that recombinant plants have a great potential as a large-scale source of human IF for analytical and therapeutic purposes.......Intrinsic factor (IF) is the gastric protein that promotes the intestinal uptake of vitamin B12. Gastric IF from animal sources is used in diagnostic tests and in vitamin pills. However, administration of animal IF to humans becomes disadvantageous because of possible pathogenic transmission...

  8. Human intrinsic factor expressed in the plant Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Fedosov, Sergey N; Laursen, Niels B; Nexø, Ebba

    2003-01-01

    and contamination by other B12 binders. We tested the use of recombinant plants for large-scale production of pathogen-free human recombinant IF. Human IF was successfully expressed in the recombinant plant Arabidopsis thaliana. Extract from fresh plants possessed high B12-binding capacity corresponding to 70 mg......Intrinsic factor (IF) is the gastric protein that promotes the intestinal uptake of vitamin B12. Gastric IF from animal sources is used in diagnostic tests and in vitamin pills. However, administration of animal IF to humans becomes disadvantageous because of possible pathogenic transmission...... IF per 1 kg wet weight. The dried plants still retained 60% of the IF activity. The purified IF preparation consisted of a 50-kDa glycosylated protein with the N-terminal sequence of mature IF. Approximately one-third of the protein was cleaved at the internal site em leader PSNP downward arrow GPGP...

  9. Arabidopsis thaliana cdd1 mutant uncouples the constitutive activation of salicylic acid signalling from growth defects.

    Science.gov (United States)

    Swain, Swadhin; Roy, Shweta; Shah, Jyoti; Van Wees, Saskia; Pieterse, Corné M; Nandi, Ashis K

    2011-12-01

    Arabidopsis genotypes with a hyperactive salicylic acid-mediated signalling pathway exhibit enhanced disease resistance, which is often coupled with growth and developmental defects, such as dwarfing and spontaneous necrotic lesions on the leaves, resulting in reduced biomass yield. In this article, we report a novel recessive mutant of Arabidopsis, cdd1 (constitutive defence without defect in growth and development1), that exhibits enhanced disease resistance associated with constitutive salicylic acid signalling, but without any observable pleiotropic phenotype. Both NPR1 (NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1)-dependent and NPR1-independent salicylic acid-regulated defence pathways are hyperactivated in cdd1 mutant plants, conferring enhanced resistance against bacterial pathogens. However, a functional NPR1 allele is required for the cdd1-conferred heightened resistance against the oomycete pathogen Hyaloperonospora arabidopsidis. Salicylic acid accumulates at elevated levels in cdd1 and cdd1 npr1 mutant plants and is necessary for cdd1-mediated PR1 expression and disease resistance phenotypes. In addition, we provide data which indicate that the cdd1 mutation negatively regulates the npr1 mutation-induced hyperactivation of ethylene/jasmonic acid signalling. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.

  10. Variations in constitutive and inducible UV-B tolerance; dissecting photosystem II protection in Arabidopsis thaliana accessions.

    Science.gov (United States)

    Jansen, Marcel A K; Martret, Bénedicte Le; Koornneef, Maarten

    2010-01-01

    The rise in ultraviolet-B (UV-B) (280-315 nm) radiation levels, that is a consequence of stratospheric ozone layer depletion, has triggered extensive research on the effects of UV-B on plants. Plants raised under natural sunlight conditions are generally well protected from the potentially harmful effects of UV-B radiation. However, it is mostly unknown to which extent UV protection is constitutive and/or induced. In this study, we have analysed the role of constitutive and inducible protection responses in avoiding UV-B damage to photosystem II of photosynthesis. We have assayed the UV susceptibility of photosystem II in 224 Arabidopsis thaliana accessions from across the Northern hemisphere, and found a continuum of constitutive UV-protection levels, with some accessions being UV sensitive and others UV tolerant. Statistical analysis showed only very weak associations between constitutive UV tolerance and the geographic origin of accessions. Instead, most of the variance in constitutive UV-B protection of photosynthesis is present at the level of local Arabidopsis populations originating in the same geographic and climatic area. The variance in constitutive UV protection is, however, small compared to the amplitude of environmentally induced changes in UV protection. Thus, our data emphasise the importance of inducible responses for the protection of photosystem II against UV-B. Remarkably, the conditions that induce UV-protective responses vary; accessions from lower latitudes were found to switch-on UV defences more readily than those of higher latitudes. Such altered regulation of induction may comprise a suitable adaptation response when levels of a stressor are fluctuating in the short term, but predictable over longer periods.

  11. Heterologous expression of the wheat aquaporin gene TaTIP2;2 compromises the abiotic stress tolerance of Arabidopsis thaliana.

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    Chunhui Xu

    Full Text Available Aquaporins are channel proteins which transport water across cell membranes. We show that the bread wheat aquaporin gene TaTIP2;2 maps to the long arm of chromosome 7b and that its product localizes to the endomembrane system. The gene is expressed constitutively in both the root and the leaf, and is down-regulated by salinity and drought stress. Salinity stress induced an increased level of C-methylation within the CNG trinucleotides in the TaTIP2;2 promoter region. The heterologous expression of TaTIP2;2 in Arabidopsis thaliana compromised its drought and salinity tolerance, suggesting that TaTIP2;2 may be a negative regulator of abiotic stress. The proline content of transgenic A. thaliana plants fell, consistent with the down-regulation of P5CS1, while the expression of SOS1, SOS2, SOS3, CBF3 and DREB2A, which are all stress tolerance-related genes acting in an ABA-independent fashion, was also down-regulated. The supply of exogenous ABA had little effect either on TaTIP2;2 expression in wheat or on the phenotype of transgenic A. thaliana. The expression level of the ABA signalling genes ABI1, ABI2 and ABF3 remained unaltered in the transgenic A. thaliana plants. Thus TaTIP2;2 probably regulates the response to stress via an ABA-independent pathway(s.

  12. Phytoremediation potential of Arabidopsis thaliana, expressing ectopically a vacuolar proton pump, for the industrial waste phosphogypsum.

    Science.gov (United States)

    Khoudi, Habib; Maatar, Yafa; Brini, Faïçal; Fourati, Amine; Ammar, Najoua; Masmoudi, Khaled

    2013-01-01

    transgenic A. thaliana lines were more Cd-tolerant than the WT plants. These results suggested that ectopic expression of a vacuolar proton pump in A. thaliana plants can lead to various biotechnological applications including the phytoremediation of industrial wastes.

  13. Heterologous expression of two GPATs from Jatropha curcas alters seed oil levels in transgenic Arabidopsis thaliana.

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    Misra, Aparna; Khan, Kasim; Niranjan, Abhishek; Kumar, Vinod; Sane, Vidhu A

    2017-10-01

    Oils and fats are stored in endosperm during seed development in the form of triacylglycerols. Three acyltransferases: glycerol-3-phosphate acyltransferase (GPAT), lysophosphatidyl acyltransferase (LPAT) and diacylglycerol acyltransferase (DGAT) are involved in the storage lipid biosynthesis and catalyze the stepwise acylation of glycerol backbone. In this study two members of GPAT gene family (JcGPAT1 and JcGPAT2) from Jatropha seeds were identified and characterized. Sequence analysis suggested that JcGPAT1 and JcGPAT2 are homologous to Arabidopsis acyltransferase-1 (ATS1) and AtGPAT9 respectively. The sub-cellular localization studies of these two GPATs showed that JcGPAT1 localizes into plastid whereas JcGPAT2 localizes in to endoplasmic reticulum. JcGPAT1 and JcGPAT2 expressed throughout the seed development with higher expression in fully matured seed compared to immature seed. The transcript levels of JcGPAT2 were higher in comparison to JcGPAT1 in different developmental stages of seed. Over-expression of JcGPAT1 and JcGPAT2 under constitutive and seed specific promoters in Arabidopsis thaliana increased total oil content. Transgenic seeds of JcGPAT2-OE lines accumulated 43-60% more oil than control seeds whereas seeds of Arabidopsis lines over-expressing plastidial GPAT lead to only 13-20% increase in oil content. Functional characterization of GPAT homologues of Jatropha in Arabidopsis suggested that these are involved in oil biosynthesis but might have specific roles in Jatropha. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Differentially expressed genes associated with dormancy or germination of Arabidopsis thaliana seeds

    NARCIS (Netherlands)

    Toorop, P.E.; Barroco, R.M.; Engler, G.; Groot, S.P.C.; Hilhorst, H.W.M.

    2005-01-01

    Differential display analysis using dormant and non-dormant Arabidopsis thaliana (L.) Heynh seeds resulted in a set of genes that were associated with either dormancy or germination. Expression of the germination-associated genes AtRPL36B and AtRPL27B, encoding two ribosomal proteins, was

  15. Vacuolar and cytosolic cytokinin dehydrogenases of Arabidopsis thaliana: heterologous expression, purification and properties

    Czech Academy of Sciences Publication Activity Database

    Kowalska, M.; Galuszka, Petr; Frébortová, Jitka; Šebela, M.; Béres, Tibor; Hluska, T.; Šmehilová, M.; Bilyeu, K. D.; Frébort, Ivo

    2010-01-01

    Roč. 71, č. 17 (2010), s. 1970-1978 ISSN 0031-9422 R&D Projects: GA ČR GA301/08/1649 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arabidopsis thaliana * Pichia pastoris expression system * Electron acceptor Subject RIV: CE - Biochemistry Impact factor: 3.150, year: 2010

  16. Comparative differential gene expression analysis of nucleus-encoded proteins for Rafflesia cantleyi against Arabidopsis thaliana

    Science.gov (United States)

    Ng, Siuk-Mun; Lee, Xin-Wei; Wan, Kiew-Lian; Firdaus-Raih, Mohd

    2015-09-01

    Regulation of functional nucleus-encoded proteins targeting the plastidial functions was comparatively studied for a plant parasite, Rafflesia cantleyi versus a photosynthetic plant, Arabidopsis thaliana. This study involved two species of different feeding modes and different developmental stages. A total of 30 nucleus-encoded proteins were found to be differentially-regulated during two stages in the parasite; whereas 17 nucleus-encoded proteins were differentially-expressed during two developmental stages in Arabidopsis thaliana. One notable finding observed for the two plants was the identification of genes involved in the regulation of photosynthesis-related processes where these processes, as expected, seem to be present only in the autotroph.

  17. The Arabidopsis DREB2 genetic pathway is constitutively repressed by basal phosphoinositide-dependent phospholipase C coupled to diacylglycerol kinase in Arabidopsis thaliana

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    Nabila eDjafi

    2013-08-01

    Full Text Available Phosphoinositide-dependent phospholipases C (PI-PLCs are activated in response to various stimuli. They utilize substrates provided by type III-Phosphatidylinositol-4 kinases (PI4KIII to produce inositol triphosphate and diacylglycerol (DAG that is phosphorylated into phosphatidic acid (PA by DAG-kinases (DGKs. The roles of PI4KIIIs, PI-PLCs and DGKs in basal signalling are poorly understood. We investigated the control of gene expression by basal PI-PLC pathway in Arabidopsis thaliana suspension cells. A transcriptome-wide analysis allowed the identification of genes whose expression was altered by edelfosine, 30 µM wortmannin or R59022, inhibitors of PI-PLCs, PI4KIIIs and DGKs, respectively. We found that a gene responsive to one of these molecules is more likely to be similarly regulated by the other two inhibitors. The common action of these agents is to inhibit PA formation, showing that basal PI-PLCs act, in part, on gene expression through their coupling to DGKs. Amongst the genes up-regulated in presence of the inhibitors, were some DREB2 genes, in suspension cells and in seedlings. The DREB2 genes encode transcription factors with major roles in responses to environmental stresses, including dehydration. They bind to C-repeat motifs, known as Drought-Responsive Elements, that are indeed enriched in the promoters of genes up-regulated by PI-PLC pathway inhibitors. PA can also be produced by phospholipases D (PLDs. We show that the DREB2 genes that are up-regulated by PI-PLC inhibitors are positively or negatively regulated, or indifferent, to PLD basal activity. Our data show that the DREB2 genetic pathway is constitutively repressed in resting conditions and that DGK coupled to PI-PLC is active in this process, in suspension cells and seedlings. We discuss how this basal negative regulation of DREB2 genes is compatible with their stress-triggered positive regulation.

  18. Recombinant vectors construction for cellobiohydrolase encoding gene constitutive expression

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    Leontina GURGU

    2012-12-01

    Full Text Available Cellobiohydrolases (EC 3.2.1.91 are important exo enzymes involved in cellulose hydrolysis alongside endoglucanases (EC 3.2.1.4 and β-glucosidases (EC 3.2.1.21. Heterologous cellobiohydrolase gene expression under constitutive promoter control using Saccharomyces cerevisiae as host system is of great importance for a successful SSF process. From this point of view, the main objective of the work was to use Yeplac181 expression vector as a recipient for cellobiohdrolase - cbhB encoding gene expression under the control of the actin promoter, in Saccharomyces cerevisiae. Two hybridvectors, YEplac-Actp and YEplac-Actp-CbhB, were generated usingEscherichia coli XLI Blue for the cloning experiments. Constitutive cbhB gene expression was checked by proteine gel electrophoresis (SDS-PAGE after insertion of these constructs into Saccharomyces cerevisiae.

  19. Expression of artificial microRNAs in transgenic Arabidopsis thaliana confers virus resistance.

    Science.gov (United States)

    Niu, Qi-Wen; Lin, Shih-Shun; Reyes, Jose Luis; Chen, Kuan-Chun; Wu, Hui-Wen; Yeh, Shyi-Dong; Chua, Nam-Hai

    2006-11-01

    Plant microRNAs (miRNAs) regulate the abundance of target mRNAs by guiding their cleavage at the sequence complementary region. We have modified an Arabidopsis thaliana miR159 precursor to express artificial miRNAs (amiRNAs) targeting viral mRNA sequences encoding two gene silencing suppressors, P69 of turnip yellow mosaic virus (TYMV) and HC-Pro of turnip mosaic virus (TuMV). Production of these amiRNAs requires A. thaliana DICER-like protein 1. Transgenic A. thaliana plants expressing amiR-P69(159) and amiR-HC-Pro(159) are specifically resistant to TYMV and TuMV, respectively. Expression of amiR-TuCP(159) targeting TuMV coat protein sequences also confers specific TuMV resistance. However, transgenic plants that express both amiR-P69(159) and amiR-HC-Pro(159) from a dimeric pre-amiR-P69(159)/amiR-HC-Pro(159) transgene are resistant to both viruses. The virus resistance trait is displayed at the cell level and is hereditable. More important, the resistance trait is maintained at 15 degrees C, a temperature that compromises small interfering RNA-mediated gene silencing. The amiRNA-mediated approach should have broad applicability for engineering multiple virus resistance in crop plants.

  20. Identification of imprinted genes subject to parent-of-origin specific expression in Arabidopsis thaliana seeds

    LENUS (Irish Health Repository)

    McKeown, Peter C

    2011-08-12

    Abstract Background Epigenetic regulation of gene dosage by genomic imprinting of some autosomal genes facilitates normal reproductive development in both mammals and flowering plants. While many imprinted genes have been identified and intensively studied in mammals, smaller numbers have been characterized in flowering plants, mostly in Arabidopsis thaliana. Identification of additional imprinted loci in flowering plants by genome-wide screening for parent-of-origin specific uniparental expression in seed tissues will facilitate our understanding of the origins and functions of imprinted genes in flowering plants. Results cDNA-AFLP can detect allele-specific expression that is parent-of-origin dependent for expressed genes in which restriction site polymorphisms exist in the transcripts derived from each allele. Using a genome-wide cDNA-AFLP screen surveying allele-specific expression of 4500 transcript-derived fragments, we report the identification of 52 maternally expressed genes (MEGs) displaying parent-of-origin dependent expression patterns in Arabidopsis siliques containing F1 hybrid seeds (3, 4 and 5 days after pollination). We identified these MEGs by developing a bioinformatics tool (GenFrag) which can directly determine the identities of transcript-derived fragments from (i) their size and (ii) which selective nucleotides were added to the primers used to generate them. Hence, GenFrag facilitates increased throughput for genome-wide cDNA-AFLP fragment analyses. The 52 MEGs we identified were further filtered for high expression levels in the endosperm relative to the seed coat to identify the candidate genes most likely representing novel imprinted genes expressed in the endosperm of Arabidopsis thaliana. Expression in seed tissues of the three top-ranked candidate genes, ATCDC48, PDE120 and MS5-like, was confirmed by Laser-Capture Microdissection and qRT-PCR analysis. Maternal-specific expression of these genes in Arabidopsis thaliana F1 seeds was

  1. Identification of imprinted genes subject to parent-of-origin specific expression in Arabidopsis thaliana seeds

    Directory of Open Access Journals (Sweden)

    Wennblom Trevor J

    2011-08-01

    Full Text Available Abstract Background Epigenetic regulation of gene dosage by genomic imprinting of some autosomal genes facilitates normal reproductive development in both mammals and flowering plants. While many imprinted genes have been identified and intensively studied in mammals, smaller numbers have been characterized in flowering plants, mostly in Arabidopsis thaliana. Identification of additional imprinted loci in flowering plants by genome-wide screening for parent-of-origin specific uniparental expression in seed tissues will facilitate our understanding of the origins and functions of imprinted genes in flowering plants. Results cDNA-AFLP can detect allele-specific expression that is parent-of-origin dependent for expressed genes in which restriction site polymorphisms exist in the transcripts derived from each allele. Using a genome-wide cDNA-AFLP screen surveying allele-specific expression of 4500 transcript-derived fragments, we report the identification of 52 maternally expressed genes (MEGs displaying parent-of-origin dependent expression patterns in Arabidopsis siliques containing F1 hybrid seeds (3, 4 and 5 days after pollination. We identified these MEGs by developing a bioinformatics tool (GenFrag which can directly determine the identities of transcript-derived fragments from (i their size and (ii which selective nucleotides were added to the primers used to generate them. Hence, GenFrag facilitates increased throughput for genome-wide cDNA-AFLP fragment analyses. The 52 MEGs we identified were further filtered for high expression levels in the endosperm relative to the seed coat to identify the candidate genes most likely representing novel imprinted genes expressed in the endosperm of Arabidopsis thaliana. Expression in seed tissues of the three top-ranked candidate genes, ATCDC48, PDE120 and MS5-like, was confirmed by Laser-Capture Microdissection and qRT-PCR analysis. Maternal-specific expression of these genes in Arabidopsis thaliana F1

  2. Kontrolle der Expression des UNUSUAL FLORAL ORGANS (UFO) Gens in Arabidopsis thaliana

    OpenAIRE

    Hobe, Martin

    2004-01-01

    Die vorliegende Arbeit befaßt sich mit der Kontrolle des Expressionsmusters des UNUSUAL FLORAL ORGANS (UFO) Gens von Arabidopsis thaliana. UFO wird im Sproß- und Blütenmeristemen aller Entwicklungsstadien der Pflanze exprimiert. In Blütenmeristemen agiert UFO als Kofaktor von LEAFY (LFY) bei der Aktivierung der Organidentitätsgene des zweiten und dritten Wirtels. UFO stellt also einen generellen Faktor der Musterbildung in Meristemen dar. Um regulatorische Gene, die die Expression von UFO bee...

  3. Time-Delay Effects on Constitutive Gene Expression*

    International Nuclear Information System (INIS)

    Feng Yan-Ling; Wang Dan; Tang Xu-Lei; Dong Jian-Min

    2017-01-01

    The dynamics of constitutive gene expression with delayed mRNA degradation is investigated, where the intrinsic noise caused by the small number of reactant molecules is introduced. It is found that the oscillatory behavior claimed in previous investigations does not appear in the approximation of small time delay, and the steady state distribution still follows the Poisson law. Furthermore, we introduce the extrinsic noise induced by surrounding environment to explore the effects of this noise and time delay on the Fano factor. Based on a delay Langevin equation and the corresponding Fokker–Planck equation, the distribution of mRNA copy-number is achieved analytically. The time delay and extrinsic noise play similar roles in the gene expression system, that is, they are able to result in the deviation of the Fano factor from 1 evidently. The measured Fano factor for constitutive gene expression is slightly larger than 1, which is perhaps attributed to the time-delay effect. (paper)

  4. Growth enhancement and gene expression of Arabidopsis thaliana irradiated with active oxygen species

    Science.gov (United States)

    Watanabe, Satoshi; Ono, Reoto; Hayashi, Nobuya; Shiratani, Masaharu; Tashiro, Kosuke; Kuhara, Satoru; Inoue, Asami; Yasuda, Kaori; Hagiwara, Hiroko

    2016-07-01

    The characteristics of plant growth enhancement effect and the mechanism of the enhancement induced by plasma irradiation are investigated using various active species in plasma. Active oxygen species in oxygen plasma are effective for growth enhancement of plants. DNA microarray analysis of Arabidopsis thaliana indicates that the genes coding proteins that counter oxidative stresses by eliminating active oxygen species are expressed at significantly high levels. The size of plant cells increases owing to oxygen plasma irradiation. The increases in gene expression levels and cell size suggest that the increase in the expression level of the expansin protein is essential for plant growth enhancement phenomena.

  5. Probing cytokinin homeostasis in Arabidopsis thaliana by constitutively overexpressing two forms of the maize cytokinin oxidase/dehydrogenase 1 gene

    Czech Academy of Sciences Publication Activity Database

    Kopečný, D.; Tarkowski, Petr; Majira, M.; Bouchez-Mahiout, I.; Nogué, F.; Laurière, M.; Sandberg, G.; Laloue, M.; Houba-Hérin, N.

    2006-01-01

    Roč. 171, č. 1 (2006), s. 114-122 ISSN 0168-9452 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arabidopsis thaliana * Cytokinin oxidase/dehydrogenase * Homeostasis Subject RIV: CE - Biochemistry Impact factor: 1.631, year: 2006

  6. Gravity-regulated gene expression in Arabidopsis thaliana

    Science.gov (United States)

    Sederoff, Heike; Brown, Christopher S.; Heber, Steffen; Kajla, Jyoti D.; Kumar, Sandeep; Lomax, Terri L.; Wheeler, Benjamin; Yalamanchili, Roopa

    Plant growth and development is regulated by changes in environmental signals. Plants sense environmental changes and respond to them by modifying gene expression programs to ad-just cell growth, differentiation, and metabolism. Functional expression of genes comprises many different processes including transcription, translation, post-transcriptional and post-translational modifications, as well as the degradation of RNA and proteins. Recently, it was discovered that small RNAs (sRNA, 18-24 nucleotides long), which are heritable and systemic, are key elements in regulating gene expression in response to biotic and abiotic changes. Sev-eral different classes of sRNAs have been identified that are part of a non-cell autonomous and phloem-mobile network of regulators affecting transcript stability, translational kinetics, and DNA methylation patterns responsible for heritable transcriptional silencing (epigenetics). Our research has focused on gene expression changes in response to gravistimulation of Arabidopsis roots. Using high-throughput technologies including microarrays and 454 sequencing, we iden-tified rapid changes in transcript abundance of genes as well as differential expression of small RNA in Arabidopsis root apices after minutes of reorientation. Some of the differentially regu-lated transcripts are encoded by genes that are important for the bending response. Functional mutants of those genes respond faster to reorientation than the respective wild type plants, indicating that these proteins are repressors of differential cell elongation. We compared the gravity responsive sRNAs to the changes in transcript abundances of their putative targets and identified several potential miRNA: target pairs. Currently, we are using mutant and transgenic Arabidopsis plants to characterize the function of those miRNAs and their putative targets in gravitropic and phototropic responses in Arabidopsis.

  7. Gene expression analysis of WRKY transcription factors in Arabidopsis thaliana cell cultures during a parabolic flight

    Science.gov (United States)

    Babbick, Maren; Barjaktarović, Žarko; Hampp, Ruediger

    Plants sense gravity by specialized cells (statocytes) and adjust growth and development accordingly. It has, however, also been shown that plant cells which are not part of specialized tissues are also able to sense gravitational forces. Therefore we used undifferentiated, homogeneous cell cultures of Arabidopsis thaliana (cv. Columbia) in order to identify early alterations in gene expression as a response to altered gravitational field strengths. In this contribution we report on cell cultures exposed to parabolic flights (approximately 20 sec of microgravity). For this short-term exposure study, we specifically checked for genes at the beginning of signal transduction chains, such as those coding for transcription factors (TFs). TFs are small proteins that regulate expression of their target genes by binding to specific promoter sequences. Our main focus were members of the so-called WRKY TF family. WRKY TFs are known to be involved in various physiological processes like senescence and pathogen defense. By quantifying transcriptional changes of these genes by real-time RT-PCR, we wanted to find out, how gene expression is affected by both hyperand microgravity conditions during a parabolic flight. For this purpose Arabidopsis thaliana callus cultures were metabolically quenched by the injection of RNAlater at the end of the microgravity-phase of each parabola. The data we present will show how fast changes in amounts of transcripts will occur, and to what degree the expression profiles are comparable with data obtained from exposures to hypergravity and simulated microgravity.

  8. Sugar regulation of SUGAR TRANSPORTER PROTEIN 1 (STP1) expression in Arabidopsis thaliana

    Science.gov (United States)

    Cordoba, Elizabeth; Aceves-Zamudio, Denise Lizeth; Hernández-Bernal, Alma Fabiola; Ramos-Vega, Maricela; León, Patricia

    2015-01-01

    Sugars regulate the expression of many genes at the transcriptional level. In Arabidopsis thaliana, sugars induce or repress the expression of >1800 genes, including the STP1 (SUGAR TRANSPORTER PROTEIN 1) gene, which encodes an H+/monosaccharide cotransporter. STP1 transcript levels decrease more rapidly after the addition of low concentrations of sugars than the levels of other repressed genes, such as DIN6 (DARK-INDUCED 6). We found that this regulation is exerted at the transcriptional level and is initiated by phosphorylatable sugars. Interestingly, the sugar signal that modulates STP1 expression is transmitted through a HEXOKINASE 1-independent signalling pathway. Finally, analysis of the STP1 5′ regulatory region allowed us to delimit a region of 309bp that contains the cis elements implicated in the glucose regulation of STP1 expression. Putative cis-acting elements involved in this response were identified. PMID:25281700

  9. Evaluation of glyphosate resistance in Arabidopsis thaliana expressing an altered target site EPSPS.

    Science.gov (United States)

    Sammons, R Douglas; You, Jinsong; Qi, Youlin; Flasinski, Stanislaw; Kavanaugh, Christina; Washam, Jeannie; Ostrander, Elizabeth; Wang, Dafu; Heck, Greg

    2018-05-01

    Glyphosate-resistant goosegrass has recently evolved and is homozygous for the double mutant of EPSPS (T 102 I, P 106 S or TIPS). These same mutations combined with EPSPS overexpression, have been used to create transgenic glyphosate-resistant crops. Arabidopsis thaliana (Wt EPSPS K i ∼ 0.5 μM) was engineered to express a variant AtEPSPS-T 102 I, P 106 A (TIPA K i = 150 μM) to determine the resistance magnitude for a more potent variant EPSPS that might evolve in weeds. Transgenic A. thaliana plants, homozygous for one, two or four copies of AtEPSPS-TIPA, had resistance (IC 50 values, R/S) as measured by seed production ranging from 4.3- to 16-fold. Plants treated in reproductive stage were male sterile with a range of R/S from 10.1- to 40.6-fold. A significant hormesis (∼ 63% gain in fresh weight) was observed for all genotypes when treated at the initiation of reproductive stage with 0.013 kg ha -1 . AtEPSPS-TIPA enzyme activity was proportional to copy number and correlated with resistance magnitude. A. thaliana, as a model weed expressing one copy of AtEPSPS-TIPA (300-fold more resistant), had only 4.3-fold resistance to glyphosate for seed production. Resistance behaved as a single dominant allele. Vegetative tissue resistance was 4.7-fold greater than reproductive tissue resistance and was linear with gene copy number. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  10. Nitrite reductase expression is regulated at the post-transcriptional level by the nitrogen source in Nicotiana plumbaginifolia and Arabidopsis thaliana.

    Science.gov (United States)

    Crété, P; Caboche, M; Meyer, C

    1997-04-01

    Higher plant nitrite reductase (NiR) is a monomeric chloroplastic protein catalysing the reduction of nitrite, the product of nitrate reduction, to ammonium. The expression of this enzyme is controlled at the transcriptional level by light and by the nitrogen source. In order to study the post-transcriptional regulation of NiR, Nicotiana plumbaginifolia and Arabidopsis thaliana were transformed with a chimaeric NiR construct containing the tobacco leaf NiR1 coding sequence driven by the CaMV 35S RNA promoter. Transformed plants did not show any phenotypic difference when compared with the wild-type, although they overexpressed NiR activity in the leaves. When these plants were grown in vitro on media containing either nitrate or ammonium as sole nitrogen source, NiR mRNA derived from transgene expression was constitutively expressed, whereas NiR activity and protein level were strongly reduced on ammonium-containing medium. These results suggest that, together with transcriptional control, post-transcriptional regulation by the nitrogen source is operating on NiR expression. This post-transcriptional regulation of tobacco leaf NiR1 expression was observed not only in the closely related species N. plumbaginifolia but also in the more distant species A. thaliana.

  11. Studies on gene expressions analyses for Arabidopsis thaliana plants stimulated by space flight condition

    Science.gov (United States)

    Lu, Jinying; Liu, Min; Pan, Yi; Li, Huasheng

    We carried out whole-genome microarray to screen the transcript profile of Arabidopsis thaliana seedlings after three treatment: space microgravity condition( Seedlings grown in microgravity state of space flight of SIMBOX on Shenzhou-8), 1g centrifugal force in space(Seedlings grown in 1g centrifugal force state of space flight of SIMBOX on Shenzhou-8) and ground control. The result of microarray analysis is as followed: There were 368 genes significantly differentially expressed in space microgravity condition compared with that in 1g centrifuge space condition. Space radiation caused 246 genes significantly differentially expressed between seedlings in 1g centrifuge space condition and ground control. Space conditions (including microgravity and radiation) caused 621 genes significantly differentially expressed between seedlings in space microgravity condition and ground control. Microgravity and radiation as a single factor can cause plant gene expression change, but two factors synergism can produce some new effects on plant gene expression. The function of differential expression genes were analyst by bioinformatics, and we found the expression of genes related with stress were more different, such as the dehydration of protein (dehydrin Xero2) expression is up-regulated 57 times; low-temperature-induced protein expression is up-regulated in 49 times; heat shock protein expression is up-regulated 20 times; transcription factor DREB2A expression increase 25 times; protein phosphatase 2C expression is up-regulated 14 times; transcription factor NAM-like protein expression is up-regulated 13 times; cell wall metabolism related genes (xyloglucan, endo-1, 4-beta-D-glucanase) expression is down-regulated in 15 times. The results provide scientific data for the mechanism of space mutation.

  12. Enhanced Toxic Metal Accumulation in Engineered Bacterial Cells Expressing Arabidopsis thaliana Phytochelatin Synthase

    Science.gov (United States)

    Sauge-Merle, Sandrine; Cuiné, Stéphan; Carrier, Patrick; Lecomte-Pradines, Catherine; Luu, Doan-Trung; Peltier, Gilles

    2003-01-01

    Phytochelatins (PCs) are metal-binding cysteine-rich peptides, enzymatically synthesized in plants and yeasts from glutathione in response to heavy metal stress by PC synthase (EC 2.3.2.15). In an attempt to increase the ability of bacterial cells to accumulate heavy metals, the Arabidopsis thaliana gene encoding PC synthase (AtPCS) was expressed in Escherichia coli. A marked accumulation of PCs was observed in vivo together with a decrease in the glutathione cellular content. When bacterial cells expressing AtPCS were placed in the presence of heavy metals such as cadmium or the metalloid arsenic, cellular metal contents were increased 20- and 50-fold, respectively. We discuss the possibility of using genes of the PC biosynthetic pathway to design bacterial strains or higher plants with increased abilities to accumulate toxic metals, and also arsenic, for use in bioremediation and/or phytoremediation processes. PMID:12514032

  13. Spatio-Temporal Expression Patterns of Arabidopsis thaliana and Medicago truncatula Defensin-Like Genes

    Science.gov (United States)

    Nallu, Sumitha; Wang, Lin; Botanga, Christopher J.; Gomez, S. Karen; Costa, Liliana M.; Harrison, Maria J.; Samac, Deborah A.; Glazebrook, Jane; Katagiri, Fumiaki; Gutierrez-Marcos, Jose F.; VandenBosch, Kathryn A.

    2013-01-01

    Plant genomes contain several hundred defensin-like (DEFL) genes that encode short cysteine-rich proteins resembling defensins, which are well known antimicrobial polypeptides. Little is known about the expression patterns or functions of many DEFLs because most were discovered recently and hence are not well represented on standard microarrays. We designed a custom Affymetrix chip consisting of probe sets for 317 and 684 DEFLs from Arabidopsis thaliana and Medicago truncatula, respectively for cataloging DEFL expression in a variety of plant organs at different developmental stages and during symbiotic and pathogenic associations. The microarray analysis provided evidence for the transcription of 71% and 90% of the DEFLs identified in Arabidopsis and Medicago, respectively, including many of the recently annotated DEFL genes that previously lacked expression information. Both model plants contain a subset of DEFLs specifically expressed in seeds or fruits. A few DEFLs, including some plant defensins, were significantly up-regulated in Arabidopsis leaves inoculated with Alternaria brassicicola or Pseudomonas syringae pathogens. Among these, some were dependent on jasmonic acid signaling or were associated with specific types of immune responses. There were notable differences in DEFL gene expression patterns between Arabidopsis and Medicago, as the majority of Arabidopsis DEFLs were expressed in inflorescences, while only a few exhibited root-enhanced expression. By contrast, Medicago DEFLs were most prominently expressed in nitrogen-fixing root nodules. Thus, our data document salient differences in DEFL temporal and spatial expression between Arabidopsis and Medicago, suggesting distinct signaling routes and distinct roles for these proteins in the two plant species. PMID:23527067

  14. An extensive (co-expression analysis tool for the cytochrome P450 superfamily in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Provart Nicholas J

    2008-04-01

    Full Text Available Abstract Background Sequencing of the first plant genomes has revealed that cytochromes P450 have evolved to become the largest family of enzymes in secondary metabolism. The proportion of P450 enzymes with characterized biochemical function(s is however very small. If P450 diversification mirrors evolution of chemical diversity, this points to an unexpectedly poor understanding of plant metabolism. We assumed that extensive analysis of gene expression might guide towards the function of P450 enzymes, and highlight overlooked aspects of plant metabolism. Results We have created a comprehensive database, 'CYPedia', describing P450 gene expression in four data sets: organs and tissues, stress response, hormone response, and mutants of Arabidopsis thaliana, based on public Affymetrix ATH1 microarray expression data. P450 expression was then combined with the expression of 4,130 re-annotated genes, predicted to act in plant metabolism, for co-expression analyses. Based on the annotation of co-expressed genes from diverse pathway annotation databases, co-expressed pathways were identified. Predictions were validated for most P450s with known functions. As examples, co-expression results for P450s related to plastidial functions/photosynthesis, and to phenylpropanoid, triterpenoid and jasmonate metabolism are highlighted here. Conclusion The large scale hypothesis generation tools presented here provide leads to new pathways, unexpected functions, and regulatory networks for many P450s in plant metabolism. These can now be exploited by the community to validate the proposed functions experimentally using reverse genetics, biochemistry, and metabolic profiling.

  15. Spatio-temporal expression patterns of Arabidopsis thaliana and Medicago truncatula defensin-like genes.

    Directory of Open Access Journals (Sweden)

    Mesfin Tesfaye

    Full Text Available Plant genomes contain several hundred defensin-like (DEFL genes that encode short cysteine-rich proteins resembling defensins, which are well known antimicrobial polypeptides. Little is known about the expression patterns or functions of many DEFLs because most were discovered recently and hence are not well represented on standard microarrays. We designed a custom Affymetrix chip consisting of probe sets for 317 and 684 DEFLs from Arabidopsis thaliana and Medicago truncatula, respectively for cataloging DEFL expression in a variety of plant organs at different developmental stages and during symbiotic and pathogenic associations. The microarray analysis provided evidence for the transcription of 71% and 90% of the DEFLs identified in Arabidopsis and Medicago, respectively, including many of the recently annotated DEFL genes that previously lacked expression information. Both model plants contain a subset of DEFLs specifically expressed in seeds or fruits. A few DEFLs, including some plant defensins, were significantly up-regulated in Arabidopsis leaves inoculated with Alternaria brassicicola or Pseudomonas syringae pathogens. Among these, some were dependent on jasmonic acid signaling or were associated with specific types of immune responses. There were notable differences in DEFL gene expression patterns between Arabidopsis and Medicago, as the majority of Arabidopsis DEFLs were expressed in inflorescences, while only a few exhibited root-enhanced expression. By contrast, Medicago DEFLs were most prominently expressed in nitrogen-fixing root nodules. Thus, our data document salient differences in DEFL temporal and spatial expression between Arabidopsis and Medicago, suggesting distinct signaling routes and distinct roles for these proteins in the two plant species.

  16. High yield expression and purification of equilibrative nucleoside transporter 7 (ENT7) from Arabidopsis thaliana.

    Science.gov (United States)

    Girke, Christopher; Arutyunova, Elena; Syed, Maria; Traub, Michaela; Möhlmann, Torsten; Lemieux, M Joanne

    2015-09-01

    Equilibrative nucleoside transporters (ENTs) facilitate the import of nucleosides and their analogs into cells in a bidirectional, non-concentrative manner. However, in contrast to their name, most characterized plant ENTs act in a concentrative manner. A direct characterization of any ENT protein has been hindered due to difficulties in overexpression and obtaining pure recombinant protein. The equilibrative nucleoside transporter 7 from Arabidopsis thaliana (AtENT7) was expressed in Xenopus laevis oocytes to assess mechanism of substrate uptake. Recombinant protein fused to enhanced green fluorescent protein (eGFP) was expressed in Pichia pastoris to characterize its oligomeric state by gel filtration and substrate binding by microscale thermophoresis (MST). AtENT7 expressed in X. laevis oocytes works as a classic equilibrative transporter. The expression of AtENT7-eGFP in the P. pastoris system yielded milligram amounts of pure protein that exists as stable homodimers. The concentration dependent binding of purine and pyrimidine nucleosides to the purified recombinant protein, assessed by MST, confirmed that AtENT7-eGFP is properly folded. For the first time the binding of nucleobases was observed for AtENT7. The availability of pure recombinant AtENT7 will permit detailed kinetic and structural studies of this unique member of the ENT family and, given the functional similarity to mammalian ENTs, will serve as a good model for understanding the structural basis of translocation mechanism for the family. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Identification and Expression Profiling of Radiation-sensitive Genes Using Plant Model System, Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Kim, Dong-Sub; Kang, Si-Yong; Lee, Geung-Joo; Kim, Jin-Baek

    2008-06-01

    The purpose of this study is to characterize genes specifically expressed in response to ionizing energy (gamma-rays) of acute irradiation and elucidate signalling mechanisms via functional analysis of isolated genes in Arabidopsis thaliana. Recent improvements in DNA microarray technologies and bioinformatics have made it possible to look for common features of ionizing radiation-responsive genes and their regulatory regions. It has produced massive quantities of gene expression and other functional genomics data, and its application will increase in plant genomics. In this study, we used oligonucleotide microarrays to detect the Arabidopsis genes expressed differentially by a gamma-irradiation during the vegetative (VT, 21 DAG) and reproductive (RT, 28 DAG) stages. Wild-type (Ler) Arabidopsis was irradiated with gamma-rays with 100 and 800 Gy doses. Among the 21,500 genes represented in the Agilent chip, approximately 13,500 ( ∼ 61.4 %) responsive genes to ν -irradiation were expressed with signal intensity greater than 192 when compared to the combined control (non-irradiated vegetative and reproductive pool). Expression patterns of several radiation inducible genes were confirmed by RT-PCR and Northern blotting. Our microarray results may contribute to an overall understanding of the type and quantities of genes that are expressed by an acute gamma-irradiation. In addition, to investigate the oxidative damage caused by irradiation, RT-PCR analysis for the expression of antioxidant isoenzyme genes, and a Transmission Electron Microscope (TEM) observation for visualizing the H 2 O 2 scavenging activity in leaves were applied

  18. Heat shock protein Hsp90-2 expression in the Arabidopsis thaliana seedlings under clinorotation

    Science.gov (United States)

    Kozeko, Liudmyla

    Heat shock proteins 90 kDa (Hsp90) are abundant under normal conditions and induced by stress. This family is distinguished from other chaperones in that most of its substrates are signal transduction proteins. Previously, we determined some time-dependent increase in the Hsp90 level in pea seedlings in response to simulated microgravity that indicated a stress-reaction. However, expression of the individual members of the Hsp90 family have specific pattern. The purpose of this study was to investigate possible alterations in the gene expression pattern of cytosolic Hsp90-2 in Arabidopsis thaliana seedlings under 2D-clinorotation. To obtain detailed expression pattern of the HSP90-2 genes we used seeds that provides a resource of loss-of-function mutations gene expression patterns via translational fusions with the reporter gene, GUS (a line N 166718, NASC). There were two variants of the experiment: 1) seedlings grew under clinorotation for 10, 12, 14 d; 2) seedlings grew in the stationary conditions for 10 d followed by clinorotation for 3 h -at 22o C and 16h light cycle. The seedlings grown in the stationary conditions were used as a control. GUS staining showed that HSP90-2 expression was regulated during seedling development and affected by clinorotation in the heterozygous mutant plants. In the homozygous for the mutation plants, HSP90-2 expression was stable during seedling development and not affected by clinorotation. GUS staining was observed in cotyledons, leaves and hypocotyls of the seedlings (especially intense in vascular bundles), indicating intensive cellular processes with participation of this chaperone. Possible pathways of influence of clinorotation on HSP90-2 expression are discussed.

  19. Identification and Expression Profiling of Radiation-sensitive Genes Using Plant Model System, Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Sub; Kang, Si-Yong; Lee, Geung-Joo; Kim, Jin-Baek

    2008-06-15

    The purpose of this study is to characterize genes specifically expressed in response to ionizing energy (gamma-rays) of acute irradiation and elucidate signalling mechanisms via functional analysis of isolated genes in Arabidopsis thaliana. Recent improvements in DNA microarray technologies and bioinformatics have made it possible to look for common features of ionizing radiation-responsive genes and their regulatory regions. It has produced massive quantities of gene expression and other functional genomics data, and its application will increase in plant genomics. In this study, we used oligonucleotide microarrays to detect the Arabidopsis genes expressed differentially by a gamma-irradiation during the vegetative (VT, 21 DAG) and reproductive (RT, 28 DAG) stages. Wild-type (Ler) Arabidopsis was irradiated with gamma-rays with 100 and 800 Gy doses. Among the 21,500 genes represented in the Agilent chip, approximately 13,500 ({sup {approx}}61.4 %) responsive genes to {nu} -irradiation were expressed with signal intensity greater than 192 when compared to the combined control (non-irradiated vegetative and reproductive pool). Expression patterns of several radiation inducible genes were confirmed by RT-PCR and Northern blotting. Our microarray results may contribute to an overall understanding of the type and quantities of genes that are expressed by an acute gamma-irradiation. In addition, to investigate the oxidative damage caused by irradiation, RT-PCR analysis for the expression of antioxidant isoenzyme genes, and a Transmission Electron Microscope (TEM) observation for visualizing the H{sub 2}O{sub 2} scavenging activity in leaves were applied.

  20. Gene expression and hormone autonomy in radiation-induced tumors of Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Persinger, S.M.; Town, C.D.

    1989-01-01

    In order to study the molecular genetics of factor controlling plant cell growth, we have isolated a group of radiation-induced tumors from Arabidopsis thaliana. Tumors appeared on plants derived from 60 Co gamma-irradiated seed or seedlings, and are capable of hormone-autonomous growth in culture. We have used vertebrate oncogene probes to explore the hypothesis that the tumors arose by the radiation-induced activation of growth-regulating plant oncogenes. One probe, int-2, was used to isolate cDNA clones representing an mRNA differentially expressed between tumors and hormone-dependent callus tissue. The genomic organization and function of this and other differentially expressed Arabidopsis sequences are being further characterized. A second area of study concerns the hormonal status of individual tumors. Tumor tissue varies in color, texture, and degree of differentiation: while some tumors appear undifferentiated, one consistently produces roots, and others occasionally develop shoots or leaflets. The tumors have characteristic growth rates on hormone-free medium, and growth in response to exogenous hormones differs among the tumors themselves and from wild-type. Characterization of the relationships between hormonal status, morphogenesis, and gene expression should yield valuable insights into the mechanisms regulating plant growth and development

  1. Constitutive and regulated expression vectors to construct polyphosphate deficient bacteria

    Directory of Open Access Journals (Sweden)

    Jerez Carlos A

    2009-03-01

    Full Text Available Abstract Background Inorganic polyphosphate (polyP, a polymer of tens or hundreds of phosphate residues linked by ATP-like bonds, is found in all organisms and performs a wide variety of functions. PolyP is synthesized in bacterial cells by the actions of polyphosphate kinases (PPK1 and PPK2 and degraded by an exopolyphosphatase (PPX. Bacterial cells with polyP deficiencies are impaired in many structural and important cellular functions such as motility, quorum sensing, biofilm formation and virulence. Knockout mutants of the ppk1 gene have been the most frequent strategy employed to generate polyP deficient cells. Results As an alternative method to construct polyP-deficient bacteria we developed constitutive and regulated broad-host-range vectors for depleting the cellular polyP content. This was achieved by the overexpression of yeast exopolyphosphatase (PPX1. Using this approach in a polyphosphate accumulating bacteria (Pseudomonas sp. B4, we were able to eliminate most of the cellular polyP (>95%. Furthermore, the effect of overexpression of PPX1 resembled the functional defects found in motility and biofilm formation in a ppk1 mutant from Pseudomonas aeruginosa PAO1. The plasmids constructed were also successfully replicated in other bacteria such as Escherichia coli, Burkholderia and Salmonella. Conclusion To deplete polyP contents in bacteria broad-host-range expression vectors can be used as an alternative and more efficient method compared with the deletion of ppk genes. It is of great importance to understand why polyP deficiency affects vital cellular processes in bacteria. The construction reported in this work will be of great relevance to study the role of polyP in microorganisms with non-sequenced genomes or those in which orthologs to ppk genes have not been identified.

  2. YUCCA6 over-expression demonstrates auxin function in delaying leaf senescence in Arabidopsis thaliana

    KAUST Repository

    Kim, Jeong Im

    2011-04-21

    The Arabidopsis thaliana YUCCA family of flavin monooxygenase proteins catalyses a rate-limiting step in de novo auxin biosynthesis. A YUCCA6 activation mutant, yuc6-1D, has been shown to contain an elevated free IAA level and to display typical high-auxin phenotypes. It is reported here that Arabidopsis plants over-expressing YUCCA6, such as the yuc6-1D activation mutant and 35S:YUC6 transgenic plants, displayed dramatic longevity. In addition, plants over-expressing YUCCA6 exhibited classical, delayed dark-induced and hormone-induced senescence in assays using detached rosette leaves. However, plants over-expressing an allele of YUCCA6, that carries mutations in the NADPH cofactor binding site, exhibited neither delayed leaf senescence phenotypes nor phenotypes typical of auxin overproduction. When the level of free IAA was reduced in yuc6-1D by conjugation to lysine, yuc6-1D leaves senesced at a rate similar to the wild-type leaves. Dark-induced senescence in detached leaves was accompanied by a decrease in their free IAA content, by the reduced expression of auxin biosynthesis enzymes such as YUCCA1 and YUCCA6 that increase cellular free IAA levels, and by the increased expression of auxin-conjugating enzymes encoded by the GH3 genes that reduce the cellular free auxin levels. Reduced transcript abundances of SAG12, NAC1, and NAC6 during senescence in yuc6-1D compared with the wild type suggested that auxin delays senescence by directly or indirectly regulating the expression of senescence-associated genes. 2011 The Author(s).

  3. Heterologous Expression of Two Jatropha Aquaporins Imparts Drought and Salt Tolerance and Improves Seed Viability in Transgenic Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Kasim Khan

    Full Text Available Drought and high salinity are environmental conditions that cause adverse effects on the growth and productivity of crops. Aquaporins are small integral membrane proteins that belong to the family of the major intrinsic proteins (MIPs, with members in animals, plants and microbes, where they facilitate the transport of water and/or small neutral solutes thereby affecting water balance. In this study we characterized two aquaporin genes namely, plasma membrane intrinsic protein (PIP2;7 and tonoplast intrinsic protein TIP1;3 from Jatropha curcas that are localised to the plasma membrane and vacuole respectively. Transgenic Arabidopsis thaliana lines over-expressing JcPIP2;7 and JcTIP1;3 under a constitutive promoter show improved germination under high salt and mannitol compared to control seeds. These transgenic plants also show increased root length under abiotic stress conditions compared to wild type Col-0 plants. Transgenic lines exposed to drought conditions by withholding water for 20 days, were able to withstand water stress and attained normal growth after re-watering unlike control plants which could not survive. Transgenic lines also had better seed yield than control under salt stress. Importantly, seed viability of transgenic plants grown under high salt concentration was 35%-45% compared to less than 5% for control seeds obtained from plants growing under salt stress. The effect of JcPIP2;7 and JcTIP1;3 on improving germination and seed viability in drought and salinity make these important candidates for genetic manipulation of plants for growth in saline soils.

  4. The nuclear immune receptor RPS4 is required for RRS1SLH1-dependent constitutive defense activation in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Kee Hoon Sohn

    2014-10-01

    Full Text Available Plant nucleotide-binding leucine-rich repeat (NB-LRR disease resistance (R proteins recognize specific "avirulent" pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs. How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4 and RRS1 (resistance to Ralstonia solanacearum 1, function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NB-LRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1 mutant encodes an RRS1 allele (RRS1SLH1 with a single amino acid (leucine insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed

  5. DOG1 expression is predicted by the seed-maturation envornment and contributes to geographical variation in germination in Arabidopsis thaliana

    NARCIS (Netherlands)

    Chiang, G.C.K.; Bartsch, M.; Barua, D.; Nakabayashi, K.; Debieu, M.; Kronholm, I.; Koornneef, M.; Soppe, W.J.J.; Donohue, K.; Meaux, De J.

    2011-01-01

    Seasonal germination timing of Arabidopsis thaliana strongly influences overall life history expression and is the target of intense natural selection. This seasonal germination timing depends strongly on the interaction between genetics and seasonal environments both before and after seed

  6. The constitutional right to freedom of expression: How enforceable ...

    African Journals Online (AJOL)

    Erna Kinsey

    have been directly affected by the need to ensure that their operations and rules are constitutionally and legislatively compatible. .... decisions about dress in the educational context of the school. .... time, until she was paid at the end of the month, to purchase the shoes ..... The Promotion of Equality and Prevention of Unfair.

  7. The constitutional right to freedom of expression: how enforceable ...

    African Journals Online (AJOL)

    reaching consequences on society. As organs of state, schools have been directly affected by the need to ensure that their operations and rules are constitutionally and legislatively compatible. Human rights do not exist purely as an ideal but must ...

  8. Superoxide-responsive gene expression in Arabidopsis thaliana and Zea mays.

    Science.gov (United States)

    Xu, Junhuan; Tran, Thu; Padilla Marcia, Carmen S; Braun, David M; Goggin, Fiona L

    2017-08-01

    Superoxide (O 2 - ) and other reactive oxygen species (ROS) are generated in response to numerous biotic and abiotic stresses. Different ROS have been reported to elicit different transcriptional responses in plants, and so ROS-responsive marker genes and promoter::reporter gene fusions have been proposed as indirect means of detecting ROS and discriminating among different species. However, further information about the specificity of transcriptional responses to O 2 - is needed in order to assess potential markers for this critical stress-responsive signaling molecule. Using qRT-PCR, the expression of 12 genes previously reported to be upregulated by O 2 - was measured in Arabidopsis thaliana plants exposed to elicitors of common stress-responsive ROS: methyl viologen (an inducer of O 2 - ), rose bengal (an inducer of singlet oxygen, 1 ΔO 2 ), and exogenous hydrogen peroxide (H 2 O 2 ). Surprisingly, Zinc-Finger Protein 12 (AtZAT12), which had previously been used as a reporter for H 2 O 2 , responded more strongly to O 2 - than to H 2 O 2 ; moreover, the expression of an AtZAT12 promoter-reporter fusion (AtZAT12::Luc) was enhanced by diethyldithiocarbamate, which inhibits dismutation of O 2 - to H 2 O 2 . These results suggest that AtZAT12 is transcriptionally upregulated in response to O 2 - , and that AtZAT12::Luc may be a useful biosensor for detecting O 2 - generation in vivo. In addition, transcripts encoding uncoupling proteins (AtUCPs) showed selectivity for O 2 - in Arabidopsis, and an AtUCP homolog upregulated by methyl viologen was also identified in maize (Zea mays L.), indicating that there are O 2 - -responsive members of this family in monocots. These results expand our limited knowledge of ROS-responsive gene expression in monocots, as well as O 2 - -selective responses in dicots. Copyright © 2017 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

  9. Expression and crystallographic studies of the Arabidopsis thaliana GDP-D-mannose pyrophosphorylase VTC1.

    Science.gov (United States)

    Zhao, Shun; Liu, Lin

    2016-10-01

    GDP-D-mannose pyrophosphorylase catalyzes the production of GDP-D-mannose, an intermediate product in the plant ascorbic acid (AsA) biosynthetic pathway. This enzyme is a key regulatory target in AsA biosynthesis and is encoded by VITAMIN C DEFECTIVE 1 (VTC1) in the Arabidopsis thaliana genome. Here, recombinant VTC1 was expressed, purified and crystallized. Diffraction data were obtained from VTC1 crystals grown in the absence and presence of substrate using X-rays. The ligand-free VTC1 crystal diffracted X-rays to 3.3 Å resolution and belonged to space group R32, with unit-cell parameters a = b = 183.6, c = 368.5 Å, α = β = 90, γ = 120°; the crystal of VTC1 in the presence of substrate diffracted X-rays to 1.75 Å resolution and belonged to space group P2 1 , with unit-cell parameters a = 70.8, b = 83.9, c = 74.5 Å, α = γ = 90.0, β = 114.9°.

  10. Effects of aneuploidy on genome structure, expression, and interphase organization in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Bruno Huettel

    2008-10-01

    Full Text Available Aneuploidy refers to losses and/or gains of individual chromosomes from the normal chromosome set. The resulting gene dosage imbalance has a noticeable affect on the phenotype, as illustrated by aneuploid syndromes, including Down syndrome in humans, and by human solid tumor cells, which are highly aneuploid. Although the phenotypic manifestations of aneuploidy are usually apparent, information about the underlying alterations in structure, expression, and interphase organization of unbalanced chromosome sets is still sparse. Plants generally tolerate aneuploidy better than animals, and, through colchicine treatment and breeding strategies, it is possible to obtain inbred sibling plants with different numbers of chromosomes. This possibility, combined with the genetic and genomics tools available for Arabidopsis thaliana, provides a powerful means to assess systematically the molecular and cytological consequences of aberrant numbers of specific chromosomes. Here, we report on the generation of Arabidopsis plants in which chromosome 5 is present in triplicate. We compare the global transcript profiles of normal diploids and chromosome 5 trisomics, and assess genome integrity using array comparative genome hybridization. We use live cell imaging to determine the interphase 3D arrangement of transgene-encoded fluorescent tags on chromosome 5 in trisomic and triploid plants. The results indicate that trisomy 5 disrupts gene expression throughout the genome and supports the production and/or retention of truncated copies of chromosome 5. Although trisomy 5 does not grossly distort the interphase arrangement of fluorescent-tagged sites on chromosome 5, it may somewhat enhance associations between transgene alleles. Our analysis reveals the complex genomic changes that can occur in aneuploids and underscores the importance of using multiple experimental approaches to investigate how chromosome numerical changes condition abnormal phenotypes and

  11. Evolution of stress-regulated gene expression in duplicate genes of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Cheng Zou

    2009-07-01

    Full Text Available Due to the selection pressure imposed by highly variable environmental conditions, stress sensing and regulatory response mechanisms in plants are expected to evolve rapidly. One potential source of innovation in plant stress response mechanisms is gene duplication. In this study, we examined the evolution of stress-regulated gene expression among duplicated genes in the model plant Arabidopsis thaliana. Key to this analysis was reconstructing the putative ancestral stress regulation pattern. By comparing the expression patterns of duplicated genes with the patterns of their ancestors, duplicated genes likely lost and gained stress responses at a rapid rate initially, but the rate is close to zero when the synonymous substitution rate (a proxy for time is > approximately 0.8. When considering duplicated gene pairs, we found that partitioning of putative ancestral stress responses occurred more frequently compared to cases of parallel retention and loss. Furthermore, the pattern of stress response partitioning was extremely asymmetric. An analysis of putative cis-acting DNA regulatory elements in the promoters of the duplicated stress-regulated genes indicated that the asymmetric partitioning of ancestral stress responses are likely due, at least in part, to differential loss of DNA regulatory elements; the duplicated genes losing most of their stress responses were those that had lost more of the putative cis-acting elements. Finally, duplicate genes that lost most or all of the ancestral responses are more likely to have gained responses to other stresses. Therefore, the retention of duplicates that inherit few or no functions seems to be coupled to neofunctionalization. Taken together, our findings provide new insight into the patterns of evolutionary changes in gene stress responses after duplication and lay the foundation for testing the adaptive significance of stress regulatory changes under highly variable biotic and abiotic environments.

  12. The FOUR LIPS and MYB88 transcription factor genes are widely expressed in Arabidopsis thaliana during development.

    Science.gov (United States)

    Lei, Qin; Lee, EunKyoung; Keerthisinghe, Sandra; Lai, Lien; Li, Meng; Lucas, Jessica R; Wen, Xiaohong; Ren, Xiaolin; Sack, Fred D

    2015-09-01

    The FOUR LIPS (FLP) and MYB88 transcription factors, which are closely related in structure and function, control the development of stomata, as well as entry into megasporogenesis in Arabidopsis thaliana. However, other locations where these transcription factors are expressed are poorly described. Documenting additional locations where these genes are expressed might define new functions for these genes. Expression patterns were examined throughout vegetative and reproductive development. The expression from two transcriptional-reporter fusions were visualized with either β-glucuronidase (GUS) or green fluorescence protein (GFP). Both flp and myb88 genes were expressed in many, previously unreported locations, consistent with the possibility of additional functions for FLP and MYB88. Moreover, expression domains especially of FLP display sharp cutoffs or boundaries. In addition to stomatal and reproductive development, FLP and MYB88, which are R2R3 MYB transcription factor genes, are expressed in many locations in cells, tissues, and organs. © 2015 Botanical Society of America.

  13. Human eosinophils constitutively express a unique serine protease, PRSS33.

    Science.gov (United States)

    Toyama, Sumika; Okada, Naoko; Matsuda, Akio; Morita, Hideaki; Saito, Hirohisa; Fujisawa, Takao; Nakae, Susumu; Karasuyama, Hajime; Matsumoto, Kenji

    2017-07-01

    Eosinophils play important roles in asthma, especially airway remodeling, by producing various granule proteins, chemical mediators, cytokines, chemokines and proteases. However, protease production by eosinophils is not fully understood. In the present study, we investigated the production of eosinophil-specific proteases/proteinases by transcriptome analysis. Human eosinophils and other cells were purified from peripheral blood by density gradient sedimentation and negative/positive selections using immunomagnetic beads. Protease/proteinase expression in eosinophils and release into the supernatant were evaluated by microarray analysis, qPCR, ELISA, flow cytometry and immunofluorescence staining before and after stimulation with eosinophil-activating cytokines and secretagogues. mRNAs for extracellular matrix proteins in human normal fibroblasts were measured by qPCR after exposure to recombinant protease serine 33 (PRSS33) protein (rPRSS33), created with a baculovirus system. Human eosinophils expressed relatively high levels of mRNA for metalloproteinase 25 (MMP25), a disintegrin and metalloprotease 8 (ADAM8), ADAM10, ADAM19 and PRSS33. Expression of PRSS33 was the highest and eosinophil-specific. PRSS33 mRNA expression was not affected by eosinophil-activating cytokines. Immunofluorescence staining showed that PRSS33 was co-localized with an eosinophil granule protein. PRSS33 was not detected in the culture supernatant of eosinophils even after stimulation with secretagogues, but its cell surface expression was increased. rPRSS33 stimulation of human fibroblasts increased expression of collagen and fibronectin mRNAs, at least in part via protease-activated receptor-2 activation. Activated eosinophils may induce fibroblast extracellular matrix protein synthesis via cell surface expression of PRSS33, which would at least partly explain eosinophils' role(s) in airway remodeling. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier

  14. STAT3-mediated constitutive expression of SOCS-3 in cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Brender, C; Nielsen, M; Kaltoft, K

    2001-01-01

    ) obtained from affected skin from a patient with mycosis fungoides (MF) and from peripheral blood from a patient with Sezary syndrome (SS). In contrast, constitutive SOCS-3 expression is not found in the leukemic Jurkat T-cell line, the MOLT-4 acute lymphoblastic leukemia cell line, and the monocytic......, it has been hypothesized that an aberrant SOCS expression plays a role in neoplastic transformation. This study reports on a constitutive SOCS-3 expression in cutaneous T-cell lymphoma (CTCL) cell lines. SOCS-3 protein is constitutively expressed in tumor cell lines (but not in nonmalignant T cells...... leukemic cell line U937. Expression of SOCS-3 coincides with a constitutive activation of STAT3 in CTCL tumor cells, and stable transfection of CTCL tumor cells with a dominant negative STAT3 strongly inhibits SOCS-3 expression, whereas transfection with wild-type STAT3 does not. Moreover, the reduced SOCS...

  15. DOG1 expression is predicted by the seed-maturation envornment and contributes to geographical variation in germination in Arabidopsis thaliana

    OpenAIRE

    Chiang, G.C.K.; Bartsch, M.; Barua, D.; Nakabayashi, K.; Debieu, M.; Kronholm, I.; Koornneef, M.; Soppe, W.J.J.; Donohue, K.; Meaux, De, J.

    2011-01-01

    Seasonal germination timing of Arabidopsis thaliana strongly influences overall life history expression and is the target of intense natural selection. This seasonal germination timing depends strongly on the interaction between genetics and seasonal environments both before and after seed dispersal. DELAY OF GERMINATION 1 (DOG1) is the first gene that has been identified to be associated with natural variation in primary dormancy in A. thaliana. Here, we report interaccession variation in DO...

  16. YUCCA6 over-expression demonstrates auxin function in delaying leaf senescence in Arabidopsis thaliana

    KAUST Repository

    Kim, Jeong Im; Murphy, Angus S.; Baek, Dongwon; Lee, Shin-Woo; Yun, Dae-Jin; Bressan, Ray A.; Narasimhan, Meena L.

    2011-01-01

    The Arabidopsis thaliana YUCCA family of flavin monooxygenase proteins catalyses a rate-limiting step in de novo auxin biosynthesis. A YUCCA6 activation mutant, yuc6-1D, has been shown to contain an elevated free IAA level and to display typical

  17. Functional characterization of Brassica napus DNA topoisomerase Iα-1 and its effect on flowering time when expressed in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Gao, Chenhao; Qi, Shuanghui; Liu, Kaige; Li, Dong; Jin, Changyu; Duan, Shaowei; Zhang, Meng; Chen, Mingxun

    2017-01-01

    Previous studies have shown that DNA topoisomerase Iα (AtTOP1α) has specific developmental functions during growth and development in Arabidopsis thaliana. However, little is known about the roles of DNA topoisomerases in the closely related and commercially important plant, rapeseed (Brassica napus). Here, the full-length BnTOP1α-1 coding sequence was cloned from the A2 subgenome of the Brassica napus inbred line L111. We determine that all BnTOP1α paralogs showed differing patterns of expression in different organs of L111, and that when expressed in tobacco leaves as a fusion protein with green fluorescent protein, BnTOP1α-1 localized to the nucleus. We further showed that ectopic expression of BnTOP1α-1 in the A. thaliana top1α-7 mutant fully complemented the early flowering phenotype of the mutant. Moreover, altered expression levels in top1α-7 seedlings of several key genes controlling flowering time were restored to wild type levels by ectopic expression of BnTOP1α-1. These results provide valuable insights into the roles of rapeseed DNA topoisomerases in flowering time, and provide a promising target for genetic manipulation of this commercially significant process in rapeseed. - Highlights: • BnTOP1α-1 was cloned from the A2 subgenome of Brassica napus inbred line L111. • BnTOP1α-1 rescued the early flowering phenotype of the Attop1α-7 mutant. • BnTOP1α-1 rescued the altered expression of flowering time genes in the Attop1α-mutant. • The functions of BnTOP1α-1 and AtTOP1α are likely conserved.

  18. Expression of the dspA/E gene of Erwinia amylovora in non-host plant Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Hasan Murat Aksoy

    2017-01-01

    Full Text Available In the Erwinia amylovora genome, the hrp gene cluster containing the dspA/E/EB/F operon plays a crucial role in mediating the pathogenicity and the hypersensitive response (HR in the host plant. The role of the dspA/E gene derived from E. amylovora was investigated by monitoring the expression of the β-glucuronidase (GUS reporter system in transgenic Arabidopsis thaliana cv. Pri-Gus seedlings. A mutant ΔdspA/E strain of E. amylovora was generated to contain a deletion of the dspA/E gene for the purpose of this study. Two-week-old seedlings of GUS transgenic Arabidopsis were vacuum-infiltrated with the wild-type and the mutant (ΔdspA/E E. amylovora strains. The Arabidopsis seedlings were fixed and stained for GUS activity after 3–5 days following infiltration. The appearance of dense spots with blue staining on the Arabidopsis leaves indicated the typical characteristic of GUS activity. This observation indicated that the wild-type E. amylovora strain had induced a successful and efficient infection on the A. thaliana Pri-Gus leaves. In contrast, there was no visible GUS expression on leaf tissues which were inoculated with the ΔdspA/E mutant E. amylovora strain. These results indicate that the dspA/E gene is required by the bacterial cells to induce HR in non-host plants.

  19. Brief Considerations on the German Constitutional Approach of the Freedom of Expression

    Directory of Open Access Journals (Sweden)

    Carmen MOLDOVAN

    2015-08-01

    Full Text Available The process of understanding the concept of freedom of expression is very complex and it implies thorough knowledge of the constitutional values and the analysis of the constitutional tradition of different legal systems. At the same time, a balancing operation is necessary between the value of freedom of speech and other fundamental rights, process that establishes limits of the expression such as criminalizing hate speech or other actions which affect the individual dignity. The human dignity has become a constant component of the constitutional case law of many States that share the same characteristics due to the promotion of fundamental rights. In the absence of a hierarchy of rights and fundamental freedom, freedom of expression is analyzed in many cases as a primary right (Kentridge, 1996, p. 254 that prevails over other fundamental rights. This study aims to analyze the landmarks of the German constitutional interpretation of the concept of freedom of expression, to identify its scope and types of speech excluded from the constitutional protection. The choice of this constitutional legal order was justified by the complexity of this topic and the specificity of the German history and tradition, elements that have contributed to an interesting vision in the matter of conflict between different fundamental rights.

  20. Expression, purification, crystallization and preliminary X-ray diffraction analysis of Arabidopsis thaliana cyclophilin 38 (AtCyp38)

    International Nuclear Information System (INIS)

    Vasudevan, Dileep; Gopalan, Gayathri; He, Zengyong; Luan, Sheng; Swaminathan, Kunchithapadam

    2005-01-01

    Crystallization of Arabidopsis thaliana cyclophilin 38. The crystal diffracts X-rays to 2.5 Å resolution. AtCyp38 is one of the highly divergent multidomain cyclophilins from Arabidopsis thaliana. A recombinant form of AtCyp38 (residues 83–437) was expressed in Escherichia coli and purified to homogeneity. The protein was crystallized using the vapour-batch technique with PEG 6000 and t-butanol as precipitants. Crystals of recombinant AtCyp38 diffracted X-rays to better than 2.5 Å resolution at 95 K using a synchrotron-radiation source. The crystal belongs to the C-centred orthorhombic space group C222 1 , with unit-cell parameters a = 58.2, b = 95.9, c = 167.5 Å, and contains one molecule in the asymmetric unit. The selenomethionine derivative of the AtCyp38 protein was overexpressed, purified and crystallized in the same space group and data were collected to 3.5 Å at the NSLS synchrotron. The structure is being solved by the MAD method

  1. Nucleolin is required for DNA methylation state and the expression of rRNA gene variants in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Frédéric Pontvianne

    2010-11-01

    Full Text Available In eukaryotes, 45S rRNA genes are arranged in tandem arrays in copy numbers ranging from several hundred to several thousand in plants. Although it is clear that not all copies are transcribed under normal growth conditions, the molecular basis controlling the expression of specific sets of rRNA genes remains unclear. Here, we report four major rRNA gene variants in Arabidopsis thaliana. Interestingly, while transcription of one of these rRNA variants is induced, the others are either repressed or remain unaltered in A. thaliana plants with a disrupted nucleolin-like protein gene (Atnuc-L1. Remarkably, the most highly represented rRNA gene variant, which is inactive in WT plants, is reactivated in Atnuc-L1 mutants. We show that accumulated pre-rRNAs originate from RNA Pol I transcription and are processed accurately. Moreover, we show that disruption of the AtNUC-L1 gene induces loss of symmetrical DNA methylation without affecting histone epigenetic marks at rRNA genes. Collectively, these data reveal a novel mechanism for rRNA gene transcriptional regulation in which the nucleolin protein plays a major role in controlling active and repressed rRNA gene variants in Arabidopsis.

  2. Expression of pH-sensitive green fluorescent protein in Arabidopsis thaliana

    Science.gov (United States)

    Moseyko, N.; Feldman, L. J.

    2001-01-01

    This is the first report on using green fluorescent protein (GFP) as a pH reporter in plants. Proton fluxes and pH regulation play important roles in plant cellular activity and therefore, it would be extremely helpful to have a plant gene reporter system for rapid, non-invasive visualization of intracellular pH changes. In order to develop such a system, we constructed three vectors for transient and stable transformation of plant cells with a pH-sensitive derivative of green fluorescent protein. Using these vectors, transgenic Arabidopsis thaliana and tobacco plants were produced. Here the application of pH-sensitive GFP technology in plants is described and, for the first time, the visualization of pH gradients between different developmental compartments in intact whole-root tissues of A. thaliana is reported. The utility of pH-sensitive GFP in revealing rapid, environmentally induced changes in cytoplasmic pH in roots is also demonstrated.

  3. Heterologous expression of three Camellia sinensis small heat shock protein genes confers temperature stress tolerance in yeast and Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Mingle; Zou, Zhongwei; Li, Qinghui; Xin, Huahong; Zhu, Xujun; Chen, Xuan; Li, Xinghui

    2017-07-01

    CsHSP17.7, CsHSP18.1, and CsHSP21.8 expressions are induced by heat and cold stresses, and CsHSP overexpression confers tolerance to heat and cold stresses in transgenic Pichia pastoris and Arabidopsis thaliana. Small heat shock proteins (sHSPs) are crucial for protecting plants against biotic and abiotic stresses, especially heat stress. However, knowledge concerning the functions of Camellia sinensis sHSP in heat and cold stresses remains poorly understood. In this study, three C. sinensis sHSP genes (i.e., CsHSP17.7, CsHSP18.1, and CsHSP21.8) were isolated and characterized using suppression subtractive hybridization (SSH) technology. The CsHSPs expression levels in C. sinensis leaves were significantly up-regulated by heat and cold stresses. Phylogenetic analyses revealed that CsHSP17.7, CsHSP18.1, and CsHSP21.8 belong to sHSP Classes I, II, and IV, respectively. Heterologous expression of the three CsHSP genes in Pichia pastoris cells enhanced heat and cold stress tolerance. When exposed to heat and cold treatments, transgenic Arabidopsis thaliana plants overexpressing CsHSP17.7, CsHSP18.1, and CsHSP21.8 had lower malondialdehyde contents, ion leakage, higher proline contents, and transcript levels of stress-related genes (e.g., AtPOD, AtAPX1, AtP5CS2, and AtProT1) compared with the control line. In addition, improved seed germination vigor was also observed in the CsHSP-overexpressing seeds under heat stress. Taken together, our results suggest that the three identified CsHSP genes play key roles in heat and cold tolerance.

  4. Quantitative expression analysis of selected transcription factors in pavement, basal and trichome cells of mature leaves from Arabidopsis thaliana.

    Science.gov (United States)

    Schliep, Martin; Ebert, Berit; Simon-Rosin, Ulrike; Zoeller, Daniela; Fisahn, Joachim

    2010-05-01

    Gene expression levels of several transcription factors from Arabidopsis thaliana that were described previously to be involved in leaf development and trichome formation were analysed in trichome, basal and pavement cells of mature leaves. Single cell samples of these three cells types were collected by glass micro-capillaries. Real-time reverse transcription (RT)-PCR was used to analyse expression patterns of the following transcription factors: MYB23, MYB55, AtHB1, FILAMENTOUS FLOWER (FIL)/YABBY1 (YAB1), TRIPTYCHON (TRY) and CAPRICE (CPC). A difference in the expression patterns of TRY and CPC was revealed. Contrary to the CPC expression pattern, no transcripts of TRY could be detected in pavement cells. FIL/YAB1 was exclusively expressed in trichome cells. AtHB1 was highly expressed throughout all three cell types. MYB55 was higher expressed in basal cells than in trichome and pavement cells. MYB23 showed a pattern of low expression in pavement cells, medium in basal cells and high expression in trichomes. Expression patterns obtained by single cell sampling and real-time RT-PCR were compared to promoter GUS fusions of the selected transcription factors. Therefore, we regenerated two transgenic Arabidopsis lines that expressed the GUS reporter gene under control of the promoters of MYB55 and YAB1. In conclusion, despite their function in leaf morphogenesis, all six transcription factors were detected in mature leaves. Furthermore, single cell sampling and promoter GUS staining patterns demonstrated the predominant presence of MYB55 in basal cells as compared to pavement cells and trichomes.

  5. GENE EXPRESSION CHANGES IN ARABIDOPSIS THALIANA SEEDLING ROOTS EXPOSED TO THE MUNITION HEXAHYDRO-1,3,5-TRINITRO-1,3,5-TRIAZINE

    Science.gov (United States)

    Arabidopsis thaliana root transcriptome responses to the munition, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), were assessed using serial analysis of gene expression (SAGE). Comparison of the transcriptional profile for the RDX response to a profile previously described for Ar...

  6. Sequence and RT-PCR expression analysis of two peroxidases from Arabidopsis thaliana belonging to a novel evolutionary branch of plant perioxidases

    DEFF Research Database (Denmark)

    Kjærsgård, I.V.H.; Jespersen, H.M.; Rasmussen, Søren Kjærsgård

    1997-01-01

    cDNA clones encoding two new Arabidopsis thaliana peroxidases, ATP la and ATP 2a, have been identified by searching the Arabidopsis database of expressed sequence tags (dbEST). They represent a novel branch of hitherto uncharacterized plant peroxidases which is only 35% identical in amino acid...

  7. Comparisons between Arabidopsis thaliana and Drosophila melanogaster in relation to Coding and Noncoding Sequence Length and Gene Expression

    Directory of Open Access Journals (Sweden)

    Rachel Caldwell

    2015-01-01

    Full Text Available There is a continuing interest in the analysis of gene architecture and gene expression to determine the relationship that may exist. Advances in high-quality sequencing technologies and large-scale resource datasets have increased the understanding of relationships and cross-referencing of expression data to the large genome data. Although a negative correlation between expression level and gene (especially transcript length has been generally accepted, there have been some conflicting results arising from the literature concerning the impacts of different regions of genes, and the underlying reason is not well understood. The research aims to apply quantile regression techniques for statistical analysis of coding and noncoding sequence length and gene expression data in the plant, Arabidopsis thaliana, and fruit fly, Drosophila melanogaster, to determine if a relationship exists and if there is any variation or similarities between these species. The quantile regression analysis found that the coding sequence length and gene expression correlations varied, and similarities emerged for the noncoding sequence length (5′ and 3′ UTRs between animal and plant species. In conclusion, the information described in this study provides the basis for further exploration into gene regulation with regard to coding and noncoding sequence length.

  8. Expression of NO scavenging hemoglobin is involved in the timing of bolting in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Hebelstrup, Kim Henrik; Jensen, Erik Østergaard

    2008-01-01

    -symbiotic hemoglobin gene, GLB2, in Arabidopsis thaliana. Lines with GLB1 silencing had a significant delay of bolting and after bolting, shoots reverted to the rosette vegetative phase by formation of aerial rosettes at lateral meristems. Lines with overexpression of GLB1 or GLB2 bolted earlier than wild type plants....... By germinating the lines in a medium containing the nitric oxide (NO) donor, sodium nitroprusside (SNP), it was demonstrated that both GLB1 and GLB2 promote bolting by antagonizing the effect of NO, suggesting that non-symbiotic plant hemoglobin controls bolting by scavenging the floral transition signal...... molecule, NO. So far, NO scavenging has only been demonstrated for class 1 non-symbiotic hemoglobins. A direct assay in Arabidopsis leaf cells shows that GLB1 as well as the class 2 non-symbiotic hemoglobin, GLB2, scavenge NO in vivo. NO has also been demonstrated to be a growth stimulating signal...

  9. Identification of novel miRNAs and miRNA dependent developmental shifts of gene expression in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Shuhua Zhan

    Full Text Available microRNAs (miRNAs are small, endogenous RNAs of 20 approximately 25 nucleotides, processed from stem-loop regions of longer RNA precursors. Plant miRNAs act as negative regulators of target mRNAs predominately by slicing target transcripts, and a number of miRNAs play important roles in development. We analyzed a number of published datasets from Arabidopsis thaliana to characterize novel miRNAs, novel miRNA targets, and miRNA-regulated developmental changes in gene expression. These data include microarray profiling data and small RNA (sRNA deep sequencing data derived from miRNA biogenesis/transport mutants, microarray profiling data of mRNAs in a developmental series, and computational predictions of conserved genomic stem-loop structures. Our conservative analyses identified five novel mature miRNAs and seven miRNA targets, including one novel target gene. Two complementary miRNAs that target distinct mRNAs were encoded by one gene. We found that genes targeted by known miRNAs, and genes up-regulated or down-regulated in miRNA mutant inflorescences, are highly expressed in the wild type inflorescence. In addition, transcripts upregulated within the mutant inflorescences were abundant in wild type leaves and shoot meristems and low in pollen and seed. Downregulated transcripts were abundant in wild type pollen and seed and low in shoot meristems, roots and leaves. Thus, disrupting miRNA function causes the inflorescence transcriptome to resemble the leaf and meristem and to differ from pollen and seed. Applications of our computational approach to other species and the use of more liberal criteria than reported here will further expand the number of identified miRNAs and miRNA targets. Our findings suggest that miRNAs have a global role in promoting vegetative to reproductive transitions in A. thaliana.

  10. Genetic requirements for high constitutive SOS expression in recA730 mutants of Escherichia coli.

    Science.gov (United States)

    Vlašić, Ignacija; Šimatović, Ana; Brčić-Kostić, Krunoslav

    2011-09-01

    The RecA protein in its functional state is in complex with single-stranded DNA, i.e., in the form of a RecA filament. In SOS induction, the RecA filament functions as a coprotease, enabling the autodigestion of the LexA repressor. The RecA filament can be formed by different mechanisms, but all of them require three enzymatic activities essential for the processing of DNA double-stranded ends. These are helicase, 5'-3' exonuclease, and RecA loading onto single-stranded DNA (ssDNA). In some mutants, the SOS response can be expressed constitutively during the process of normal DNA metabolism. The RecA730 mutant protein is able to form the RecA filament without the help of RecBCD and RecFOR mediators since it better competes with the single-strand binding (SSB) protein for ssDNA. As a consequence, the recA730 mutants show high constitutive SOS expression. In the study described in this paper, we studied the genetic requirements for constitutive SOS expression in recA730 mutants. Using a β-galactosidase assay, we showed that the constitutive SOS response in recA730 mutants exhibits different requirements in different backgrounds. In a wild-type background, the constitutive SOS response is partially dependent on RecBCD function. In a recB1080 background (the recB1080 mutation retains only helicase), constitutive SOS expression is partially dependent on RecBCD helicase function and is strongly dependent on RecJ nuclease. Finally, in a recB-null background, the constitutive SOS expression of the recA730 mutant is dependent on the RecJ nuclease. Our results emphasize the importance of the 5'-3' exonuclease for high constitutive SOS expression in recA730 mutants and show that RecBCD function can further enhance the excellent intrinsic abilities of the RecA730 protein in vivo. Copyright © 2011, American Society for Microbiology. All Rights Reserved.

  11. Changes in Gene Expression of Arabidopsis Thaliana Cell Cultures Upon Exposure to Real and Simulated Partial- g Forces

    Science.gov (United States)

    Fengler, Svenja; Spirer, Ina; Neef, Maren; Ecke, Margret; Hauslage, Jens; Hampp, Rüdiger

    2016-06-01

    Cell cultures of the plant model organism Arabidopsis thaliana were exposed to partial- g forces during parabolic flight and clinostat experiments (0.16 g, 0.38 g and 0.5 g were tested). In order to investigate gravity-dependent alterations in gene expression, samples were metabolically quenched by the fixative RNA later Ⓡ to stabilize nucleic acids and used for whole-genome microarray analysis. An attempt to identify the potential threshold acceleration for the gravity-dependent response showed that the smaller the experienced g-force, the greater was the susceptibility of the cell cultures. Compared to short-term μ g during a parabolic flight, the number of differentially expressed genes under partial- g was lower. In addition, the effect on the alteration of amounts of transcripts decreased during partial- g parabolic flight due to the sequence of the different parabolas (0.38 g, 0.16 g and μ g). A time-dependent analysis under simulated 0.5 g indicates that adaptation occurs within minutes. Differentially expressed genes (at least 2-fold up- or down-regulated in expression) under real flight conditions were to some extent identical with those affected by clinorotation. The highest number of homologuous genes was detected within seconds of exposure to 0.38 g (both flight and clinorotation). To a considerable part, these genes deal with cell wall properties. Additionally, responses specific for clinorotation were observed.

  12. Mercuric ion reduction and resistance in transgenic Arabidopsis thaliana plants expressing a modified bacterial merA gene.

    Science.gov (United States)

    Rugh, C L; Wilde, H D; Stack, N M; Thompson, D M; Summers, A O; Meagher, R B

    1996-01-01

    With global heavy metal contamination increasing, plants that can process heavy metals might provide efficient and ecologically sound approaches to sequestration and removal. Mercuric ion reductase, MerA, converts toxic Hg2+ to the less toxic, relatively inert metallic mercury (Hg0) The bacterial merA sequence is rich in CpG dinucleotides and has a highly skewed codon usage, both of which are particularly unfavorable to efficient expression in plants. We constructed a mutagenized merA sequence, merApe9, modifying the flanking region and 9% of the coding region and placing this sequence under control of plant regulatory elements. Transgenic Arabidopsis thaliana seeds expressing merApe9 germinated, and these seedlings grew, flowered, and set seed on medium containing HgCl2 concentrations of 25-100 microM (5-20 ppm), levels toxic to several controls. Transgenic merApe9 seedlings evolved considerable amounts of Hg0 relative to control plants. The rate of mercury evolution and the level of resistance were proportional to the steady-state mRNA level, confirming that resistance was due to expression of the MerApe9 enzyme. Plants and bacteria expressing merApe9 were also resistant to toxic levels of Au3+. These and other data suggest that there are potentially viable molecular genetic approaches to the phytoremediation of metal ion pollution. Images Fig. 2 Fig. 3 Fig. 4 PMID:8622910

  13. Heterologous Expression of Secreted Bacterial BPP and HAP Phytases in Plants Stimulates Arabidopsis thaliana Growth on Phytate

    Directory of Open Access Journals (Sweden)

    Lia R. Valeeva

    2018-02-01

    Full Text Available Phytases are specialized phosphatases capable of releasing inorganic phosphate from myo-inositol hexakisphosphate (phytate, which is highly abundant in many soils. As inorganic phosphorus reserves decrease over time in many agricultural soils, genetic manipulation of plants to enable secretion of potent phytases into the rhizosphere has been proposed as a promising approach to improve plant phosphorus nutrition. Several families of biotechnologically important phytases have been discovered and characterized, but little data are available on which phytase families can offer the most benefits toward improving plant phosphorus intake. We have developed transgenic Arabidopsis thaliana plants expressing bacterial phytases PaPhyC (HAP family of phytases and 168phyA (BPP family under the control of root-specific inducible promoter Pht1;2. The effects of each phytase expression on growth, morphology and inorganic phosphorus accumulation in plants grown on phytate hydroponically or in perlite as the only source of phosphorus were investigated. The most enzymatic activity for both phytases was detected in cell wall-bound fractions of roots, indicating that these enzymes were efficiently secreted. Expression of both bacterial phytases in roots improved plant growth on phytate and resulted in larger rosette leaf area and diameter, higher phosphorus content and increased shoot dry weight, implying that these plants were indeed capable of utilizing phytate as the source of phosphorus for growth and development. When grown on phytate the HAP-type phytase outperformed its BPP-type counterpart for plant biomass production, though this effect was only observed in hydroponic conditions and not in perlite. Furthermore, we found no evidence of adverse side effects of microbial phytase expression in A. thaliana on plant physiology and seed germination. Our data highlight important functional differences between these members of bacterial phytase families and indicate

  14. Heterologous Expression of Secreted Bacterial BPP and HAP Phytases in Plants Stimulates Arabidopsis thaliana Growth on Phytate.

    Science.gov (United States)

    Valeeva, Lia R; Nyamsuren, Chuluuntsetseg; Sharipova, Margarita R; Shakirov, Eugene V

    2018-01-01

    Phytases are specialized phosphatases capable of releasing inorganic phosphate from myo -inositol hexakisphosphate (phytate), which is highly abundant in many soils. As inorganic phosphorus reserves decrease over time in many agricultural soils, genetic manipulation of plants to enable secretion of potent phytases into the rhizosphere has been proposed as a promising approach to improve plant phosphorus nutrition. Several families of biotechnologically important phytases have been discovered and characterized, but little data are available on which phytase families can offer the most benefits toward improving plant phosphorus intake. We have developed transgenic Arabidopsis thaliana plants expressing bacterial phytases PaPhyC (HAP family of phytases) and 168phyA (BPP family) under the control of root-specific inducible promoter Pht1;2 . The effects of each phytase expression on growth, morphology and inorganic phosphorus accumulation in plants grown on phytate hydroponically or in perlite as the only source of phosphorus were investigated. The most enzymatic activity for both phytases was detected in cell wall-bound fractions of roots, indicating that these enzymes were efficiently secreted. Expression of both bacterial phytases in roots improved plant growth on phytate and resulted in larger rosette leaf area and diameter, higher phosphorus content and increased shoot dry weight, implying that these plants were indeed capable of utilizing phytate as the source of phosphorus for growth and development. When grown on phytate the HAP-type phytase outperformed its BPP-type counterpart for plant biomass production, though this effect was only observed in hydroponic conditions and not in perlite. Furthermore, we found no evidence of adverse side effects of microbial phytase expression in A. thaliana on plant physiology and seed germination. Our data highlight important functional differences between these members of bacterial phytase families and indicate that future

  15. Heterologous Expression of Secreted Bacterial BPP and HAP Phytases in Plants Stimulates Arabidopsis thaliana Growth on Phytate

    Science.gov (United States)

    Valeeva, Lia R.; Nyamsuren, Chuluuntsetseg; Sharipova, Margarita R.; Shakirov, Eugene V.

    2018-01-01

    Phytases are specialized phosphatases capable of releasing inorganic phosphate from myo-inositol hexakisphosphate (phytate), which is highly abundant in many soils. As inorganic phosphorus reserves decrease over time in many agricultural soils, genetic manipulation of plants to enable secretion of potent phytases into the rhizosphere has been proposed as a promising approach to improve plant phosphorus nutrition. Several families of biotechnologically important phytases have been discovered and characterized, but little data are available on which phytase families can offer the most benefits toward improving plant phosphorus intake. We have developed transgenic Arabidopsis thaliana plants expressing bacterial phytases PaPhyC (HAP family of phytases) and 168phyA (BPP family) under the control of root-specific inducible promoter Pht1;2. The effects of each phytase expression on growth, morphology and inorganic phosphorus accumulation in plants grown on phytate hydroponically or in perlite as the only source of phosphorus were investigated. The most enzymatic activity for both phytases was detected in cell wall-bound fractions of roots, indicating that these enzymes were efficiently secreted. Expression of both bacterial phytases in roots improved plant growth on phytate and resulted in larger rosette leaf area and diameter, higher phosphorus content and increased shoot dry weight, implying that these plants were indeed capable of utilizing phytate as the source of phosphorus for growth and development. When grown on phytate the HAP-type phytase outperformed its BPP-type counterpart for plant biomass production, though this effect was only observed in hydroponic conditions and not in perlite. Furthermore, we found no evidence of adverse side effects of microbial phytase expression in A. thaliana on plant physiology and seed germination. Our data highlight important functional differences between these members of bacterial phytase families and indicate that future crop

  16. Transgenic Expression of Constitutively Active RAC1 Disrupts Mouse Rod Morphogenesis

    Science.gov (United States)

    Song, Hongman; Bush, Ronald A.; Vijayasarathy, Camasamudram; Fariss, Robert N.; Kjellstrom, Sten; Sieving, Paul A.

    2014-01-01

    Purpose. Dominant-active RAC1 rescues photoreceptor structure in Drosophila rhodopsin-null mutants, indicating an important role in morphogenesis. This report assesses the morphogenetic effect of activated RAC1 during mammalian rod photoreceptor development using transgenic mice that express constitutively active (CA) RAC1. Methods. Transgenic mice were generated by expressing CA RAC1 under control of the Rhodopsin promoter, and morphological features of the photoreceptors were evaluated by histology, immunohistochemistry, and transmission electron microscopy. Function was evaluated by electroretinography. Potential protein partners of CA RAC1 were identified by co-immunoprecipitation of retinal extracts. Results. Constitutively active RAC1 expression in differentiating rods disrupted outer retinal lamination as early as postnatal day (P)6, and many photoreceptor cell nuclei were displaced apically into the presumptive subretinal space. These photoreceptors did not develop normal inner and outer segments and had abnormal placement of synaptic elements. Some photoreceptor nuclei were also mislocalized into the inner nuclear layer. Extensive photoreceptor degeneration was subsequently observed in the adult animal. Constitutively active RAC1 formed a complex with the polarity protein PAR6 and with microtubule motor dynein in mouse retina. The normal localization of the PAR6 complex was disrupted in CA RAC1-expressing rod photoreceptors. Conclusions. Constitutively active RAC1 had a profound negative effect on mouse rod cell viability and development. Rod photoreceptors in the CA RAC1 retina exhibited a defect in polarity and migration. Constitutively active RAC1 disrupted rod morphogenesis and gave a phenotype resembling that found in the Crumbs mutant. PAR6 and dynein are two potential downstream effectors that may be involved in CA RAC1-mediated defective mouse photoreceptor morphogenesis. PMID:24651551

  17. Whole genome expression and biochemical correlates of extreme constitutional types defined in Ayurveda.

    Science.gov (United States)

    Prasher, Bhavana; Negi, Sapna; Aggarwal, Shilpi; Mandal, Amit K; Sethi, Tav P; Deshmukh, Shailaja R; Purohit, Sudha G; Sengupta, Shantanu; Khanna, Sangeeta; Mohammad, Farhan; Garg, Gaurav; Brahmachari, Samir K; Mukerji, Mitali

    2008-09-09

    Ayurveda is an ancient system of personalized medicine documented and practiced in India since 1500 B.C. According to this system an individual's basic constitution to a large extent determines predisposition and prognosis to diseases as well as therapy and life-style regime. Ayurveda describes seven broad constitution types (Prakritis) each with a varying degree of predisposition to different diseases. Amongst these, three most contrasting types, Vata, Pitta, Kapha, are the most vulnerable to diseases. In the realm of modern predictive medicine, efforts are being directed towards capturing disease phenotypes with greater precision for successful identification of markers for prospective disease conditions. In this study, we explore whether the different constitution types as described in Ayurveda has molecular correlates. Normal individuals of the three most contrasting constitutional types were identified following phenotyping criteria described in Ayurveda in Indian population of Indo-European origin. The peripheral blood samples of these individuals were analysed for genome wide expression levels, biochemical and hematological parameters. Gene Ontology (GO) and pathway based analysis was carried out on differentially expressed genes to explore if there were significant enrichments of functional categories among Prakriti types. Individuals from the three most contrasting constitutional types exhibit striking differences with respect to biochemical and hematological parameters and at genome wide expression levels. Biochemical profiles like liver function tests, lipid profiles, and hematological parameters like haemoglobin exhibited differences between Prakriti types. Functional categories of genes showing differential expression among Prakriti types were significantly enriched in core biological processes like transport, regulation of cyclin dependent protein kinase activity, immune response and regulation of blood coagulation. A significant enrichment of

  18. Isolation and characterization of an auxin-inducible glutathione S-transferase gene of Arabidopsis thaliana

    NARCIS (Netherlands)

    Kop, D.A.M. van der; Schuyer, M.; Scheres, B.J.G.; Zaal, B.J. van der; Hooykaas, P.J.J.

    1996-01-01

    Genes homologous to the auxin-inducible Nt103 glutathione S-transferase (GST) gene of tobacco, were isolated from a genomic library of Arabidopsis thaliana. We isolated a λ clone containing an auxin-inducible gene, At103-1a, and part of a constitutively expressed gene, At103-1b. The coding regions

  19. Constitutive type VI secretion system expression gives Vibrio cholerae intra- and interspecific competitive advantages.

    Directory of Open Access Journals (Sweden)

    Daniel Unterweger

    Full Text Available The type VI secretion system (T6SS mediates protein translocation across the cell membrane of Gram-negative bacteria, including Vibrio cholerae - the causative agent of cholera. All V. cholerae strains examined to date harbor gene clusters encoding a T6SS. Structural similarity and sequence homology between components of the T6SS and the T4 bacteriophage cell-puncturing device suggest that the T6SS functions as a contractile molecular syringe to inject effector molecules into prokaryotic and eukaryotic target cells. Regulation of the T6SS is critical. A subset of V. cholerae strains, including the clinical O37 serogroup strain V52, express T6SS constitutively. In contrast, pandemic strains impose tight control that can be genetically disrupted: mutations in the quorum sensing gene luxO and the newly described regulator gene tsrA lead to constitutive T6SS expression in the El Tor strain C6706. In this report, we examined environmental V. cholerae isolates from the Rio Grande with regard to T6SS regulation. Rough V. cholerae lacking O-antigen carried a nonsense mutation in the gene encoding the global T6SS regulator VasH and did not display virulent behavior towards Escherichia coli and other environmental bacteria. In contrast, smooth V. cholerae strains engaged constitutively in type VI-mediated secretion and displayed virulence towards prokaryotes (E. coli and other environmental bacteria and a eukaryote (the social amoeba Dictyostelium discoideum. Furthermore, smooth V. cholerae strains were able to outcompete each other in a T6SS-dependent manner. The work presented here suggests that constitutive T6SS expression provides V. cholerae with an advantage in intraspecific and interspecific competition.

  20. Low glutathione regulates gene expression and the redox potentials of the nucleus and cytosol in Arabidopsis thaliana.

    Science.gov (United States)

    Schnaubelt, Daniel; Queval, Guillaume; Dong, Yingping; Diaz-Vivancos, Pedro; Makgopa, Matome Eugene; Howell, Gareth; De Simone, Ambra; Bai, Juan; Hannah, Matthew A; Foyer, Christine H

    2015-02-01

    Reduced glutathione (GSH) is considered to exert a strong influence on cellular redox homeostasis and to regulate gene expression, but these processes remain poorly characterized. Severe GSH depletion specifically inhibited root meristem development, while low root GSH levels decreased lateral root densities. The redox potential of the nucleus and cytosol of Arabidopsis thaliana roots determined using roGFP probes was between -300 and -320 mV. Growth in the presence of the GSH-synthesis inhibitor buthionine sulfoximine (BSO) increased the nuclear and cytosolic redox potentials to approximately -260 mV. GSH-responsive genes including transcription factors (SPATULA, MYB15, MYB75), proteins involved in cell division, redox regulation (glutaredoxinS17, thioredoxins, ACHT5 and TH8) and auxin signalling (HECATE), were identified in the GSH-deficient root meristemless 1-1 (rml1-1) mutant, and in other GSH-synthesis mutants (rax1-1, cad2-1, pad2-1) as well as in the wild type following the addition of BSO. Inhibition of auxin transport had no effect on organ GSH levels, but exogenous auxin decreased the root GSH pool. We conclude that GSH depletion significantly increases the redox potentials of the nucleus and cytosol, and causes arrest of the cell cycle in roots but not shoots, with accompanying transcript changes linked to altered hormone responses, but not oxidative stress. © 2013 John Wiley & Sons Ltd.

  1. Transgenerational changes in plant physiology and in transposon expression in response to UV-C stress in Arabidopsis thaliana.

    Science.gov (United States)

    Migicovsky, Zoe; Kovalchuk, Igor

    2014-01-01

    Stress has a negative impact on crop yield by altering a gain in biomass and affecting seed set. Recent reports suggest that exposure to stress also influences the response of the progeny. In this paper, we analyzed seed size, leaf size, bolting time and transposon expression in 2 consecutive generations of Arabidopsis thaliana plants exposed to moderate UV-C stress. Since previous reports suggested a potential role of Dicer-like (DCL) proteins in the establishment of transgenerational response, we used dcl2, dcl3 and dcl4 mutants in parallel with wild-type plants. These studies revealed that leaf number decreased in the progeny of UV-C stressed plants, and bolting occurred later. Transposons were also re-activated in the progeny of stressed plants. Changes in the dcl mutants were less prominent than in wild-type plants. DCL2 and DCL3 appeared to be more important in the transgenerational stress memory than DCL4 because transgenerational changes were less profound in the dcl2 and dcl3 mutants.

  2. Foxl1-Expressing Mesenchymal Cells Constitute the Intestinal Stem Cell NicheSummary

    Directory of Open Access Journals (Sweden)

    Reina Aoki

    2016-03-01

    Full Text Available Background & Aims: Intestinal epithelial stem cells that express leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5 and/or B cell specific Moloney murine leukemia virus integration site 1 (Bmi1 continuously replicate and generate differentiated cells throughout life. Previously, Paneth cells were suggested to constitute an epithelium-intrinsic niche that regulates the behavior of these stem cells. However, ablating Paneth cells has no effect on the maintenance of functional stem cells. Here, we show definitively that a small subset of mesenchymal subepithelial cells expressing the winged-helix transcription factor forkhead box l1 (Foxl1 are a critical component of the intestinal stem cell niche. Methods: We genetically ablated Foxl1+ mesenchymal cells in adult mice using 2 separate models by expressing either the human or simian diphtheria toxin receptor under Foxl1 promoter control. Conclusions: Killing Foxl1+ cells by diphtheria toxin administration led to an abrupt cessation of proliferation of both epithelial stem- and transit-amplifying progenitor cell populations that was associated with a loss of active Wnt signaling to the intestinal epithelium. Therefore, Foxl1-expressing mesenchymal cells constitute the fundamental niche for intestinal stem cells. Keywords: Intestinal Stem Cell Niche, Wnt, Mesenchyme

  3. Controlled expression of pectic enzymes in Arabidopsis thaliana enhances biomass conversion without adverse effects on growth.

    Science.gov (United States)

    Tomassetti, Susanna; Pontiggia, Daniela; Verrascina, Ilaria; Reca, Ida Barbara; Francocci, Fedra; Salvi, Gianni; Cervone, Felice; Ferrari, Simone

    2015-04-01

    Lignocellulosic biomass from agriculture wastes is a potential source of biofuel, but its use is currently limited by the recalcitrance of the plant cell wall to enzymatic digestion. Modification of the wall structural components can be a viable strategy to overcome this bottleneck. We have previously shown that the expression of a fungal polygalacturonase (pga2 from Aspergillus niger) in Arabidopsis and tobacco plants reduces the levels of de-esterified homogalacturonan in the cell wall and significantly increases saccharification efficiency. However, plants expressing pga2 show stunted growth and reduced biomass production, likely as a consequence of an extensive loss of pectin integrity during the whole plant life cycle. We report here that the expression in Arabidopsis of another pectic enzyme, the pectate lyase 1 (PL1) of Pectobacterium carotovorum, under the control of a chemically inducible promoter, results, after induction of the transgene, in a saccharification efficiency similar to that of plants expressing pga2. However, lines with high levels of transgene induction show reduced growth even in the absence of the inducer. To overcome the problem of plant fitness, we have generated Arabidopsis plants that express pga2 under the control of the promoter of SAG12, a gene expressed only during senescence. These plants expressed pga2 only at late stages of development, and their growth was comparable to that of WT plants. Notably, leaves and stems of transgenic plants were more easily digested by cellulase, compared to WT plants, only during senescence. Expression of cell wall-degrading enzymes at the end of the plant life cycle may be therefore a useful strategy to engineer crops unimpaired in biomass yield but improved for bioconversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Arabidopsis thaliana MLO genes are expressed in discrete domains during reproductive development.

    Science.gov (United States)

    Davis, Thomas C; Jones, Daniel S; Dino, Arianna J; Cejda, Nicholas I; Yuan, Jing; Willoughby, Andrew C; Kessler, Sharon A

    2017-12-01

    MLOs in Plant Reproduction. The MILDEW RESISTANCE LOCUS-O (MLO) protein family, comprised of 15 members, plays roles in diverse cell-cell communication processes such as powdery mildew susceptibility, root thigmomorphogenesis, and pollen tube reception. The NORTIA (NTA, AtMLO7) gene is expressed in the synergid cells of the female gametophyte where it functions in intercellular communication with the pollen tube. Discrepancies between previously published promoter::GUS and promoter::gene-GUS constructs expression patterns led us to explore the regulation of NTA expression. Here we found via NTA pro ::gNTA-GUS truncations that sequences within the NTA gene negatively regulate its expression in the stomata and carpel walls. This led to the hypothesis that other MLO family members may also have additional regulatory sequences within the gene. MLO pro ::gMLO-GUS constructs were examined for each family member focusing specifically on flowers in order to determine whether other MLOs could play a role in reproductive cell-cell communication. Notably, several MLOs were expressed in the pollen, in the stigma, in the pollinated style, and in the synergids and central cell. These findings indicate that other MLOs in addition to NTA could play a role in reproduction. Previous studies on the MLO family showed that phylogenetically related MLOs had redundant functions in powdery mildew infection and root thigmomorphogenesis; however, MLO expression in reproductive tissues did not strictly follow phylogenetic relationships, indicating that MLOs from different evolutionary origins may have been recruited for function in sexual reproduction.

  5. Integrating ribosomal promoter vectors that offer a choice of constitutive expression profiles in Leishmania donovani.

    Science.gov (United States)

    Soysa, Radika; Tran, Khoa D; Ullman, Buddy; Yates, Phillip A

    2015-12-01

    We have designed a novel series of integrating ribosomal RNA promoter vectors with five incrementally different constitutive expression profiles, covering a 250-fold range. Differential expression was achieved by placing different combinations of synthetic or leishmanial DNA sequences upstream and downstream of the transgene coding sequence in order to modulate pre-mRNA processing efficiency and mRNA stability, respectively. All of the vectors have extensive multiple cloning sites, and versions are available for producing N- or C- terminal GFP fusions at each of the possible relative expression levels. In addition, the modular configuration of the vectors allows drug resistance cassettes and other components to be readily exchanged. In toto, these vectors should be useful additions to the toolkit available for molecular and genetic studies of Leishmania donovani. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Geomagnetic Field (Gmf) and Plant Evolution: Investigating the Effects of Gmf Reversal on Arabidopsis thaliana Development and Gene Expression.

    Science.gov (United States)

    Bertea, Cinzia M; Narayana, Ravishankar; Agliassa, Chiara; Rodgers, Christopher T; Maffei, Massimo E

    2015-11-30

    One of the most stimulating observations in plant evolution is a correlation between the occurrence of geomagnetic field (GMF) reversals (or excursions) and the moment of the radiation of Angiosperms. This led to the hypothesis that alterations in GMF polarity may play a role in plant evolution. Here, we describe a method to test this hypothesis by exposing Arabidopsis thaliana to artificially reversed GMF conditions. We used a three-axis magnetometer and the collected data were used to calculate the magnitude of the GMF. Three DC power supplies were connected to three Helmholtz coil pairs and were controlled by a computer to alter the GMF conditions. Plants grown in Petri plates were exposed to both normal and reversed GMF conditions. Sham exposure experiments were also performed. Exposed plants were photographed during the experiment and images were analyzed to calculate root length and leaf areas. Arabidopsis total RNA was extracted and Quantitative Real Time-PCR (qPCR) analyses were performed on gene expression of CRUCIFERIN 3 (CRU3), copper transport protein1 (COTP1), Redox Responsive Transcription Factor1 (RRTF1), Fe Superoxide Dismutase 1, (FSD1), Catalase3 (CAT3), Thylakoidal Ascorbate Peroxidase (TAPX), a cytosolic Ascorbate Peroxidase1 (APX1), and NADPH/respiratory burst oxidase protein D (RbohD). Four different reference genes were analysed to normalize the results of the qPCR. The best of the four genes was selected and the most stable gene for normalization was used. Our data show for the first time that reversing the GMF polarity using triaxial coils has significant effects on plant growth and gene expression. This supports the hypothesis that GMF reversal contributes to inducing changes in plant development that might justify a higher selective pressure, eventually leading to plant evolution.

  7. Conditional expression of constitutively active estrogen receptor {alpha} in chondrocytes impairs longitudinal bone growth in mice

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Kazuhiro [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Tsukui, Tohru [Experimental Animal Laboratory, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Imazawa, Yukiko; Horie-Inoue, Kuniko [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Inoue, Satoshi, E-mail: INOUE-GER@h.u-tokyo.ac.jp [Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan); Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan); Department of Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo (Japan)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Conditional transgenic mice expressing constitutively active estrogen receptor {alpha} (caER{alpha}) in chondrocytes were developed. Black-Right-Pointing-Pointer Expression of caER{alpha} in chondrocytes impaired longitudinal bone growth in mice. Black-Right-Pointing-Pointer caER{alpha} affects chondrocyte proliferation and differentiation. Black-Right-Pointing-Pointer This mouse model is useful for understanding the physiological role of ER{alpha}in vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caER{alpha}{sup ColII}, expressing constitutively active mutant estrogen receptor (ER) {alpha} in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caER{alpha}{sup ColII} mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caER{alpha}{sup ColII} mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caER{alpha}{sup ColII} mice. These results suggest that ER{alpha} is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.

  8. Conditional expression of constitutively active estrogen receptor α in chondrocytes impairs longitudinal bone growth in mice

    International Nuclear Information System (INIS)

    Ikeda, Kazuhiro; Tsukui, Tohru; Imazawa, Yukiko; Horie-Inoue, Kuniko; Inoue, Satoshi

    2012-01-01

    Highlights: ► Conditional transgenic mice expressing constitutively active estrogen receptor α (caERα) in chondrocytes were developed. ► Expression of caERα in chondrocytes impaired longitudinal bone growth in mice. ► caERα affects chondrocyte proliferation and differentiation. ► This mouse model is useful for understanding the physiological role of ERαin vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caERα ColII , expressing constitutively active mutant estrogen receptor (ER) α in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caERα ColII mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caERα ColII mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caERα ColII mice. These results suggest that ERα is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.

  9. Plasmodium yoelii yoelii 17XNL constitutively expressing GFP throughout the life cycle.

    Science.gov (United States)

    Ono, Takeshi; Tadakuma, Takushi; Rodriguez, Ana

    2007-03-01

    Plasmodium yoelii is a rodent parasite commonly used as a model to study malaria infection. It is the preferred model parasite for liver-stage immunological studies and is also widely used to study hepatocyte, erythrocyte and mosquito infection. We have generated a P. yoelii yoelii 17XNL line that is stably transfected with the green fluorescent protein (gfp) gene. This parasite line constitutively expresses high levels of GFP during the complete parasite life cycle including liver, blood and mosquito stages. These fluorescent parasites can be used in combination with fluorescence activated cell sorting or live microscopy for a wide range of experimental applications.

  10. The complex between SOS3 and SOS2 regulatory domain from Arabidopsis thaliana: cloning, expression, purification, crystallization and preliminary X-ray analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Barrena, María José; Moreno-Pérez, Sandra; Angulo, Iván; Martínez-Ripoll, Martín; Albert, Armando, E-mail: xalbert@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química Física ‘Rocasolano’, Consejo Superior de Investigaciones Científicas, Serrano 119, E-28006 Madrid (Spain)

    2007-07-01

    Recombinant SOS3 and SOS2 regulatory domain from A. thaliana have been coexpressed in E. coli, purified and crystallized by the hanging-drop vapour-diffusion method. An X-ray data set has been collected at 2.0 Å resolution. The salt-tolerance genes SOS3 (salt overly sensitive 3) and SOS2 (salt overly sensitive 2) regulatory domain of Arabidopsis thaliana were cloned into a polycistronic plasmid and the protein complex was expressed in Escherichia coli, allowing purification to homogeneity in three chromatographic steps. Crystals were grown using vapour-diffusion techniques. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 44.14, b = 57.39, c = 141.90 Å.

  11. Constitutive and inducible expression of SKALP/elafin provides anti-elastase defense in human epithelia.

    Science.gov (United States)

    Pfundt, R; van Ruissen, F; van Vlijmen-Willems, I M; Alkemade, H A; Zeeuwen, P L; Jap, P H; Dijkman, H; Fransen, J; Croes, H; van Erp, P E; Schalkwijk, J

    1996-01-01

    Skin-derived antileukoproteinase (SKALP), also known as elafin, is a serine proteinase inhibitor first discovered in keratinocytes from hyperproliferative human epidermis. In addition to the proteinase inhibiting domain which is directed against polymorphonuclear leukocyte (PMN) derived enzymes such as elastase and proteinase 3, SKALP contains multiple transglutaminase (TGase) substrate domains which enable crosslinking to extracellular and cell envelope proteins. Here we show that SKALP is constitutively expressed in several epithelia that are continuously subjected to inflammatory stimuli, such as the oral cavity and the vagina where it co-localizes with type 1 TGase. All epithelia from sterile body cavities are negative for SKALP. In general, stratified squamous epithelia are positive, whereas pseudostratified epithelia, simple/glandular epithelia and normal epidermis are negative. SKALP was found in fetal tissues of the oral cavity from 17 wk gestation onwards where it continued to be expressed up to adult life. Remarkably, in fetal epidermis SKALP was found from week 28 onwards, but was downregulated to undetectable levels in neonatal skin within three months, suggesting a role during pregnancy in feto-maternal interactions or in the early maturation phase of the epidermis. Immunoelectron microscopy revealed the presence of SKALP in secretory vesicles including the lamellar granules. In culture models for epidermal keratinocytes we found that expression of the endogenous SKALP gene provided protection against cell detachment caused by purified elastase or activated PMNs. Addition of exogenous recombinant SKALP fully protected the keratinocytes against PMN-dependent detachment whereas superoxide dismutase and catalase were only marginally effective. These findings strongly suggest that the constitutive expression of SKALP in squamous epithelia, and the inducible expression in epidermis participate in the control of epithelial integrity, by inhibiting PMN

  12. Transgenic mice expressing constitutive active MAPKAPK5 display gender-dependent differences in exploration and activity

    Directory of Open Access Journals (Sweden)

    Moens Ugo

    2007-11-01

    Full Text Available Abstract Background The mitogen-activated protein kinases, MAPKs for short, constitute cascades of signalling pathways involved in the regulation of several cellular processes that include cell proliferation, differentiation and motility. They also intervene in neurological processes like fear conditioning and memory. Since little remains known about the MAPK-Activated Protein Kinase, MAPKAPK5, we constructed the first MAPKAPK knockin mouse model, using a constitutive active variant of MAPKAPK5 and analyzed the resulting mice for changes in anxiety-related behaviour. Methods We performed primary SHIRPA observations during background breeding into the C57BL/6 background and assessed the behaviour of the background-bred animals on the elevated plus maze and in the light-dark test. Our results were analyzed using Chi-square tests and homo- and heteroscedatic T-tests. Results Female transgenic mice displayed increased amounts of head dips and open arm time on the maze, compared to littermate controls. In addition, they also explored further into the open arm on the elevated plus maze and were less active in the closed arm compared to littermate controls. Male transgenic mice displayed no differences in anxiety, but their locomotor activity increased compared to non-transgenic littermates. Conclusion Our results revealed anxiety-related traits and locomotor differences between transgenic mice expressing constitutive active MAPKAPK5 and control littermates.

  13. ABI3 mediates dehydration stress recovery response in Arabidopsis thaliana by regulating expression of downstream genes.

    Science.gov (United States)

    Bedi, Sonia; Sengupta, Sourabh; Ray, Anagh; Nag Chaudhuri, Ronita

    2016-09-01

    ABI3, originally discovered as a seed-specific transcription factor is now implicated to act beyond seed physiology, especially during abiotic stress. In non-seed plants, ABI3 is known to act in desiccation stress signaling. Here we show that ABI3 plays a role in dehydration stress response in Arabidopsis. ABI3 gene was upregulated during dehydration stress and its expression was maintained during subsequent stress recovery phases. Comparative gene expression studies in response to dehydration stress and stress recovery were done with genes which had potential ABI3 binding sites in their upstream regulatory regions. Such studies showed that several genes including known seed-specific factors like CRUCIFERIN1, CRUCIFERIN3 and LEA-group of genes like LEA76, LEA6, DEHYDRIN LEA and LEA-LIKE got upregulated in an ABI3-dependent manner, especially during the stress recovery phase. ABI3 got recruited to regions upstream to the transcription start site of these genes during dehydration stress response through direct or indirect DNA binding. Interestingly, ABI3 also binds to its own promoter region during such stress signaling. Nucleosomes covering potential ABI3 binding sites in the upstream sequences of the above-mentioned genes alter positions, and show increased H3 K9 acetylation during stress-induced transcription. ABI3 thus mediates dehydration stress signaling in Arabidopsis through regulation of a group of genes that play a role primarily during stress recovery phase. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Predicting protein-protein interactions in Arabidopsis thaliana through integration of orthology, gene ontology and co-expression

    Directory of Open Access Journals (Sweden)

    Vandepoele Klaas

    2009-06-01

    Full Text Available Abstract Background Large-scale identification of the interrelationships between different components of the cell, such as the interactions between proteins, has recently gained great interest. However, unraveling large-scale protein-protein interaction maps is laborious and expensive. Moreover, assessing the reliability of the interactions can be cumbersome. Results In this study, we have developed a computational method that exploits the existing knowledge on protein-protein interactions in diverse species through orthologous relations on the one hand, and functional association data on the other hand to predict and filter protein-protein interactions in Arabidopsis thaliana. A highly reliable set of protein-protein interactions is predicted through this integrative approach making use of existing protein-protein interaction data from yeast, human, C. elegans and D. melanogaster. Localization, biological process, and co-expression data are used as powerful indicators for protein-protein interactions. The functional repertoire of the identified interactome reveals interactions between proteins functioning in well-conserved as well as plant-specific biological processes. We observe that although common mechanisms (e.g. actin polymerization and components (e.g. ARPs, actin-related proteins exist between different lineages, they are active in specific processes such as growth, cancer metastasis and trichome development in yeast, human and Arabidopsis, respectively. Conclusion We conclude that the integration of orthology with functional association data is adequate to predict protein-protein interactions. Through this approach, a high number of novel protein-protein interactions with diverse biological roles is discovered. Overall, we have predicted a reliable set of protein-protein interactions suitable for further computational as well as experimental analyses.

  15. Expression variation in connected recombinant populations of Arabidopsis thaliana highlights distinct transcriptome architectures

    Directory of Open Access Journals (Sweden)

    Cubillos Francisco A

    2012-03-01

    Full Text Available Abstract Background Expression traits can vary quantitatively between individuals and have a complex inheritance. Identification of the genetics underlying transcript variation can help in the understanding of phenotypic variation due to genetic factors regulating transcript abundance and shed light into divergence patterns. So far, only a limited number of studies have addressed this subject in Arabidopsis, with contrasting results due to dissimilar statistical power. Here, we present the transcriptome architecture in leaf tissue of two RIL sets obtained from a connected-cross design involving 3 commonly used accessions. We also present the transcriptome architecture observed in developing seeds of a third independent cross. Results The utilisation of the novel R/eqtl package (which goal is to automatize and extend functions from the R/qtl package allowed us to map 4,290 and 6,534 eQTLs in the Cvi-0 × Col-0 and Bur-0 × Col-0 recombinant populations respectively. In agreement with previous studies, we observed a larger phenotypic variance explained by eQTLs in linkage with the controlled gene (potentially cis-acting, compared to distant loci (acting necessarily indirectly or in trans. Distant eQTLs hotspots were essentially not conserved between crosses, but instead, cross-specific. Accounting for confounding factors using a probabilistic approach (VBQTL increased the mapping resolution and the number of significant associations. Moreover, using local eQTLs obtained from this approach, we detected evidence for a directional allelic effect in genes with related function, where significantly more eQTLs than expected by chance were up-regulated from one of the accessions. Primary experimental data, analysis parameters, eQTL results and visualisation of LOD score curves presented here are stored and accessible through the QTLstore service database http://qtlstore.versailles.inra.fr/. Conclusions Our results demonstrate the extensive diversity and

  16. Expression Profile of Stress-responsive Arabidopsis thaliana miRNAs and their Target Genes in Response to Inoculation with Pectobacterium carotovorum subsp. carotovorum.

    Science.gov (United States)

    Djami-Tchatchou, A T; Ntushelo, K

    2017-01-01

    Pectobacterium carotovorum subsp. carotovorum (Pcc) is a soft rot bacterium which upon entry into the plant macerates plant tissues by producing plant cell wall degrading enzymes. It has a wide host range which includes carrot, potato, tomato, leafy greens, squash and other cucurbits, onion, green peppers and cassava. During plant-microbe interactions, one of the ways of plant response to pathogen infection is through the small RNA silencing mechanism. Under pathogen attack the plant utilizes microRNAs to regulate gene expression by means of mediating gene silencing at transcriptional and post-transcriptional level. This study aims to assess for the first time, the expression profile of some stress-responsive miRNA and differential expression pattern of their target genes in Arabidopsis thaliana inoculated with Pcc. Leaves of five weeks old Arabidopsis thaliana plants were infected with Pcc and the quantitative real time-PCR, was used to investigate after 0, 24, 48 and 72 h post infection, the expression profiling of the stress-responsive miRNAs which include: miR156, miR159, miR169, miR393, miR396 miR398, miR399 and miR408 along with their target genes which include: Squamosa promoter-binding-like protein, myb domain protein 101, nuclear factor Y subunit A8, concanavalin A-like lectin protein kinase, growth regulating factor 4, copper superoxide dismutase, ubiquitin-protein ligase and plantacyanin respectively. The findings showed that the overexpression of 6 miRNAs at 24, 48 and 72 h after infection resulted in the repression of their target genes and the expression of 2 miRNAs didn't affect their target genes. These results provide the first indication of the miRNAs role in response to the infection of Pcc in A. thaliana and open new vistas for a better understanding of miRNA regulation of plant response to Pcc.

  17. Cytokinin Regulation of Gene Expression in the AHP Gene Family in Arabidopsis thaliana

    Czech Academy of Sciences Publication Activity Database

    Hradilová, Jana; Malbeck, Jiří; Brzobohatý, Břetislav

    2007-01-01

    Roč. 26, č. 3 (2007), s. 229-244 ISSN 0721-7595 R&D Projects: GA MŠk LN00A081; GA MŠk 1M06030; GA MŠk(CZ) LC06034; GA AV ČR(CZ) IAA600380507; GA AV ČR IAA600040612 Institutional research plan: CEZ:AV0Z50380511; CEZ:AV0Z50040702 Source of funding: V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje Keywords : gene expression * AHP gene family * cytokinin signal transduction Subject RIV: EF - Botanics Impact factor: 2.220, year: 2007

  18. Expression of Cucumber mosaic virus suppressor 2b alters FWA methylation and its siRNA accumulation in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Sadia Hamera

    2016-11-01

    Full Text Available The Cucumber mosaic virus (CMV suppressor 2b co-localizes with AGO4 in cytoplasmic and nuclear fractions of Arabidopsis thaliana. Biochemical fractionation of A. thaliana cellular extracts revealed that 2b and AGO4 coexist in multiple size exclusions. 2b transgenic A. thaliana exhibited an enhanced accumulation of 24nt siRNAs from flowering wageningen (FWA and other heterochromatic loci. These plants also exhibited hypo-methylation of an endogenous- as well as transgene-FWA promoter at non-CG sites. In corroboration, both transgenic 2b and CMV infection affected the regulation of transposons which mimics the ago4 phenotype. In conclusion, 2b perturbs plant defense by interfering with AGO4-regulated transcriptional gene silencing.

  19. [Learning and Memory Capacity and NMDA Receptor Expression in Shen Deficiency Constitution Rats].

    Science.gov (United States)

    Sun, Yu-ru; Sun, Yao-guang; Zhang, Qi; Wang, Xiao-di; Wang, Xing; Sun, Li-jun

    2016-05-01

    To explore material bases and neurobiological mechanisms of "Shen storing will" by observing learning and memory capacities and N-methyl-D-aspartic acid (NMDA) receptor expressions in Shen deficiency constitution (SDC) rats. Totally 40 SD rats were randomly divided into the model group, the Zuogui Pill (ZP) group, the Yougui Pill (YP) group, the blank control group (consisting of normal pregnant rats), 10 in each group. SDC young rat model (inherent deficiency and postnatal malnutrition) was prepared by the classic way of "cat scaring rat". Medication started when they were scared by cat. Rats in the ZP group and the YP group were administered by gastrogavage with ZP suspension 0.1875 g/mL and YP suspension 0.0938 g/mL respectively. Equal volume of normal saline was administered to rats in the blank control group and the model group by gastrogavage. All medication was given once per day, 5 days in a week for 2 consecutive months. Learning and memory capacities were detected by Morris water maze test. Expressions of NMDA receptor subunits NR2A and NR2B in hippocamus were detected by immunohistochemical method. Compared with the blank control group, the latency period, total distance in Morris water maze test were longer in the model group (P learning and memory capacities and lowered NMDA receptor expressions. ZP and YP could up-regulate learning and memory capacities and NMDA receptor expressions, thereby improving deterioration of brain functions in SDC rats.

  20. Cesium Toxicity Alters MicroRNA Processing and AGO1 Expressions in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Il Lae Jung

    Full Text Available MicroRNAs (miRNAs are short RNA fragments that play important roles in controlled gene silencing, thus regulating many biological processes in plants. Recent studies have indicated that plants modulate miRNAs to sustain their survival in response to a variety of environmental stimuli, such as biotic stresses, cold, drought, nutritional starvation, and toxic heavy metals. Cesium and radio-cesium contaminations have arisen as serious problems that both impede plant growth and enter the food chain through contaminated plants. Many studies have been performed to define plant responses against cesium intoxication. However, the complete profile of miRNAs in plants during cesium intoxication has not been established. Here we show the differential expression of the miRNAs that are mostly down-regulated during cesium intoxication. Furthermore, we found that cesium toxicity disrupts both the processing of pri-miRNAs and AGONOUTE 1 (AGO1-mediated gene silencing. AGO 1 seems to be especially destabilized by cesium toxicity, possibly through a proteolytic regulatory pathway. Our study presents a comprehensive profile of cesium-responsive miRNAs, which is distinct from that of potassium, and suggests two possible mechanisms underlying the cesium toxicity on miRNA metabolism.

  1. Cis-regulatory PLETHORA promoter elements directing root and nodule expression are conserved between Arabidopsis thaliana and Medicago truncatula

    NARCIS (Netherlands)

    Franssen, H.G.J.M.; Kulikova, O.; Willemsen, V.A.; Heidstra, R.

    2017-01-01

    Nodules are unique organs formed on roots of legumes by soil-borne bacteria, collectively known as rhizobium. Recently, we have shown that orthologs of the AINTEGUMENTA-like (AIL) AP2 transcription factors PLETHORA (PLT) 1 to 4, that redundantly regulate Arabidopsis thaliana root development are

  2. Neutralization of Bacterial YoeBSpn Toxicity and Enhanced Plant Growth in Arabidopsis thaliana via Co-Expression of the Toxin-Antitoxin Genes

    Science.gov (United States)

    Abu Bakar, Fauziah; Yeo, Chew Chieng; Harikrishna, Jennifer Ann

    2016-01-01

    Bacterial toxin-antitoxin (TA) systems have various cellular functions, including as part of the general stress response. The genome of the Gram-positive human pathogen Streptococcus pneumoniae harbors several putative TA systems, including yefM-yoeBSpn, which is one of four systems that had been demonstrated to be biologically functional. Overexpression of the yoeBSpn toxin gene resulted in cell stasis and eventually cell death in its native host, as well as in Escherichia coli. Our previous work showed that induced expression of a yoeBSpn toxin-Green Fluorescent Protein (GFP) fusion gene apparently triggered apoptosis and was lethal in the model plant, Arabidopsis thaliana. In this study, we investigated the effects of co-expression of the yefMSpn antitoxin and yoeBSpn toxin-GFP fusion in transgenic A. thaliana. When co-expressed in Arabidopsis, the YefMSpn antitoxin was found to neutralize the toxicity of YoeBSpn-GFP. Interestingly, the inducible expression of both yefMSpn antitoxin and yoeBSpn toxin-GFP fusion in transgenic hybrid Arabidopsis resulted in larger rosette leaves and taller plants with a higher number of inflorescence stems and increased silique production. To our knowledge, this is the first demonstration of a prokaryotic antitoxin neutralizing its cognate toxin in plant cells. PMID:27104531

  3. Neutralization of Bacterial YoeBSpn Toxicity and Enhanced Plant Growth in Arabidopsis thaliana via Co-Expression of the Toxin-Antitoxin Genes

    Directory of Open Access Journals (Sweden)

    Fauziah Abu Bakar

    2016-04-01

    Full Text Available Bacterial toxin-antitoxin (TA systems have various cellular functions, including as part of the general stress response. The genome of the Gram-positive human pathogen Streptococcus pneumoniae harbors several putative TA systems, including yefM-yoeBSpn, which is one of four systems that had been demonstrated to be biologically functional. Overexpression of the yoeBSpn toxin gene resulted in cell stasis and eventually cell death in its native host, as well as in Escherichia coli. Our previous work showed that induced expression of a yoeBSpn toxin-Green Fluorescent Protein (GFP fusion gene apparently triggered apoptosis and was lethal in the model plant, Arabidopsis thaliana. In this study, we investigated the effects of co-expression of the yefMSpn antitoxin and yoeBSpn toxin-GFP fusion in transgenic A. thaliana. When co-expressed in Arabidopsis, the YefMSpn antitoxin was found to neutralize the toxicity of YoeBSpn-GFP. Interestingly, the inducible expression of both yefMSpn antitoxin and yoeBSpn toxin-GFP fusion in transgenic hybrid Arabidopsis resulted in larger rosette leaves and taller plants with a higher number of inflorescence stems and increased silique production. To our knowledge, this is the first demonstration of a prokaryotic antitoxin neutralizing its cognate toxin in plant cells.

  4. Constitutive expression of Vitreoscilla haemoglobin in Sphingomonas elodea to improve gellan gum production.

    Science.gov (United States)

    Wu, X C; Chen, Y M; Li, Y D; Li, O; Zhu, L; Qian, C D; Tao, X L; Teng, Y

    2011-02-01

    To improve a commercially used strain for gellan production by exogenous Vitreoscilla haemoglobin (VHb). VHb gene was expressed in Sphingomonas elodea under the control of constitutive bla promoter. Biochemical activity of expressed VHb was confirmed by CO-difference spectra analysis that exhibited a characteristic absorption maximum at 419 nm. During cultivation, not only enhanced cell growth was detected, but also 20% improvement in gellan production was observed after 48 h of incubation, with a maximum yield of 16·82 g l(-1). Moreover, maximum sucrose conversion efficiency (g gellan per g sucrose) was 57·8, 20% higher than that of the parental strain. We further examined the polysaccharide production of VHb-expressing strain at different aeration levels in Erlenmeyer flasks. Again, in all cases, a significant enhancement of gellan production was observed, and the enhancement was more significant under oxygen-limiting conditions (up to 26·8%). VHb exhibited positive effect on cell growth and gellan yield of S. elodea, especially under hypoxic conditions. This is the first application of VHb as an effective metabolic engineering strategy in S. elodea to regulate cell growth and optimize gellan yield. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  5. Transgenic tobacco plants constitutively expressing peanut BTF3 exhibit increased growth and tolerance to abiotic stresses.

    Science.gov (United States)

    Pruthvi, V; Rama, N; Parvathi, M S; Nataraja, K N

    2017-05-01

    Abiotic stresses limit crop growth and productivity worldwide. Cellular tolerance, an important abiotic stress adaptive trait, involves coordinated activities of multiple proteins linked to signalling cascades, transcriptional regulation and other diverse processes. Basal transcriptional machinery is considered to be critical for maintaining transcription under stressful conditions. From this context, discovery of novel basal transcription regulators from stress adapted crops like peanut would be useful for improving tolerance of sensitive plant types. In this study, we prospected a basal transcription factor, BTF3 from peanut (Arachis hypogaea L) and studied its relevance in stress acclimation by over expression in tobacco. AhBTF3 was induced under PEG-, NaCl-, and methyl viologen-induced stresses in peanut. The constitutive expression of AhBTF3 in tobacco increased plant growth under non stress condition. The transgenic plants exhibited superior phenotype compared to wild type under mannitol- and NaCl-induced stresses at seedling level. The enhanced cellular tolerance of transgenic plants was evidenced by higher cell membrane stability, reactive oxygen species (ROS) scavenging activity, seedling survival and vigour than wild type. The transgenic lines showed better in vitro regeneration capacity on growth media supplemented with NaCl than wild type. Superior phenotype of transgenic plants under osmotic and salinity stresses seems to be due to constitutive activation of genes of multiple pathways linked to growth and stress adaptation. The study demonstrated that AhBTF3 is a positive regulator of growth and stress acclimation and hence can be considered as a potential candidate gene for crop improvement towards stress adaptation. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. Expression of Stipa purpurea SpCIPK26 in Arabidopsis thaliana Enhances Salt and Drought Tolerance and Regulates Abscisic Acid Signaling

    Science.gov (United States)

    Zhou, Yanli; Sun, Xudong; Yang, Yunqiang; Li, Xiong; Cheng, Ying; Yang, Yongping

    2016-01-01

    Stipa purpurea (S. purpurea) is the dominant plant species in the alpine steppe of the Qinghai-Tibet Plateau, China. It is highly resistant to cold and drought conditions. However, the underlying mechanisms regulating the stress tolerance are unknown. In this study, a CIPK gene from S. purpurea (SpCIPK26) was isolated. The SpCIPK26 coding region consisted of 1392 bp that encoded 464 amino acids. The protein has a highly conserved catalytic structure and regulatory domain. The expression of SpCIPK26 was induced by drought and salt stress. SpCIPK26 overexpression in Arabidopsis thaliana (A. thaliana) plants provided increased tolerance to drought and salt stress in an abscisic acid (ABA)-dependent manner. Compared with wild-type A. thaliana plants, SpCIPK26-overexpressing plants had higher survival rates, water potentials, and photosynthetic efficiency (Fv/Fm), as well as lower levels of reactive oxygen species (ROS) following exposure to drought and salt stress. Gene expression analyses indicated stress-inducible genes (RD29A, RD29B, and ABF2) and a ROS-scavenger gene (CAT1) were upregulated in SpCIPK26-overexpressing plants after stress treatments. All of these marker genes are associated with ABA-responsive cis-acting elements. Additionally, the similarities in the gene expression patterns following ABA, mannitol, and NaCl treatments suggest SpCIPK26 has an important role during plant responses to drought and salt stress and in regulating ABA signaling. PMID:27338368

  7. Prediction of operon-like gene clusters in the Arabidopsis thaliana genome based on co-expression analysis of neighboring genes.

    Science.gov (United States)

    Wada, Masayoshi; Takahashi, Hiroki; Altaf-Ul-Amin, Md; Nakamura, Kensuke; Hirai, Masami Y; Ohta, Daisaku; Kanaya, Shigehiko

    2012-07-15

    Operon-like arrangements of genes occur in eukaryotes ranging from yeasts and filamentous fungi to nematodes, plants, and mammals. In plants, several examples of operon-like gene clusters involved in metabolic pathways have recently been characterized, e.g. the cyclic hydroxamic acid pathways in maize, the avenacin biosynthesis gene clusters in oat, the thalianol pathway in Arabidopsis thaliana, and the diterpenoid momilactone cluster in rice. Such operon-like gene clusters are defined by their co-regulation or neighboring positions within immediate vicinity of chromosomal regions. A comprehensive analysis of the expression of neighboring genes therefore accounts a crucial step to reveal the complete set of operon-like gene clusters within a genome. Genome-wide prediction of operon-like gene clusters should contribute to functional annotation efforts and provide novel insight into evolutionary aspects acquiring certain biological functions as well. We predicted co-expressed gene clusters by comparing the Pearson correlation coefficient of neighboring genes and randomly selected gene pairs, based on a statistical method that takes false discovery rate (FDR) into consideration for 1469 microarray gene expression datasets of A. thaliana. We estimated that A. thaliana contains 100 operon-like gene clusters in total. We predicted 34 statistically significant gene clusters consisting of 3 to 22 genes each, based on a stringent FDR threshold of 0.1. Functional relationships among genes in individual clusters were estimated by sequence similarity and functional annotation of genes. Duplicated gene pairs (determined based on BLAST with a cutoff of EOperon-like clusters tend to include genes encoding bio-machinery associated with ribosomes, the ubiquitin/proteasome system, secondary metabolic pathways, lipid and fatty-acid metabolism, and the lipid transfer system. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Degradation of lignin β-aryl ether units in Arabidopsis thaliana expressing LigD, LigF and LigG from Sphingomonas paucimobilis SYK-6

    DEFF Research Database (Denmark)

    Mnich, Ewelina; Vanholme, Ruben; Oyarce, Paula

    2017-01-01

    Lignin is a major polymer in the secondary plant cell wall and composed of hydrophobic interlinked hydroxyphenylpropanoid units. The presence of lignin hampers conversion of plant biomass into biofuels; plants with modified lignin are therefore being investigated for increased digestibility....... The bacterium Sphingomonas paucimobilis produces lignin-degrading enzymes including LigD, LigF and LigG involved in cleaving the most abundant lignin inter-unit linkage, the β-aryl ether bond. In this study, we expressed the LigD, LigF and LigG (LigDFG) genes in Arabidopsis thaliana to introduce post...

  9. Arabidopsis thaliana sucrose phosphate synthase (sps) genes are expressed differentially in organs and tissues, and their transcription is regulated by osmotic stress.

    Science.gov (United States)

    Solís-Guzmán, María Gloria; Argüello-Astorga, Gerardo; López-Bucio, José; Ruiz-Herrera, León Francisco; López-Meza, Joel Edmundo; Sánchez-Calderón, Lenin; Carreón-Abud, Yazmín; Martínez-Trujillo, Miguel

    2017-11-01

    Sucrose is synthesized from UDP-Glc and Fru-6-phosphate via the activity of sucrose-phosphate synthase (SPS) enzymes, which produce Suc-6-phosphate. Suc-6-phosphate is rapidly dephosphorylated by phosphatases to produce Suc and inorganic phosphate. Arabidopsis has four sps genes encoding SPS enzymes. Of these enzymes, AtSPS1F and AtSPS2F have been grouped with other dicotyledonous SPS enzymes, while AtSPS3F and AtSPS4F are included in groups with both dicotyledonous and monocotyledonous SPS enzymes. In this work, we generated Arabidopsis thaliana transformants containing the promoter region of each sps gene fused to gfp::uidA reporter genes. A detailed characterization of expression conferred by the sps promoters in organs and tissues was performed. We observed expression of AtSPS1F, AtSPS2F and AtSPS3F in the columella roots of the plants that support sucrose synthesis. Hence, these findings support the idea that sucrose synthesis occurs in the columella cells, and suggests that sucrose has a role in this tissue. In addition, the expression of AtSPS4F was identified in embryos and suggests its participation in this developmental stage. Quantitative transcriptional analysis of A. thaliana plants grown in media with different osmotic potential showed that AtSPS2F and AtSPS4F respond to osmotic stress. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Expression of Vitis amurensis VaERF20 in Arabidopsis thaliana Improves Resistance to Botrytis cinerea and Pseudomonas syringae pv. Tomato DC3000

    Directory of Open Access Journals (Sweden)

    Mengnan Wang

    2018-03-01

    Full Text Available Ethylene response factor (ERF transcription factors play important roles in regulating immune responses in plants. In our study, we characterized a member of the ERF transcription factor family, VaERF20, from the Chinese wild Vitis genotype, V. amurensis Rupr “Shuangyou”. Phylogenetic analysis indicated that VaERF20 belongs to group IXc of the ERF family, in which many members are known to contribute to fighting pathogen infection. Consistent with this, expression of VaERF20 was induced by treatment with the necrotrophic fungal pathogen Botrytis cinerea (B. cinerea in “Shuangyou” and V. vinifera “Red Globe”. Arabidopsis thaliana plants over-expressing VaERF20 displayed enhanced resistance to B. cinerea and the bacterium Pseudomonas syringae pv. tomato (Pst DC3000. Patterns of pathogen-induced reactive oxygen species (ROS accumulation were entirely distinct in B. cinerea and PstDC3000 inoculated plants. Examples of both salicylic acid (SA and jasmonic acid/ethylene (JA/ET responsive defense genes were up-regulated after B. cinerea and PstDC3000 inoculation of the VaERF20-overexpressing transgenic A. thaliana plants. Evidence of pattern-triggered immunity (PTI, callose accumulation and stomatal defense, together with increased expression of PTI genes, was also greater in the transgenic lines. These data indicate that VaERF20 participates in various signal transduction pathways and acts as an inducer of immune responses.

  11. Expression of cinnamyl alcohol dehydrogenases and their putative homologues during Arabidopsis thaliana growth and development: lessons for database annotations?

    Science.gov (United States)

    Kim, Sung-Jin; Kim, Kye-Won; Cho, Man-Ho; Franceschi, Vincent R; Davin, Laurence B; Lewis, Norman G

    2007-07-01

    A major goal currently in Arabidopsis research is determination of the (biochemical) function of each of its approximately 27,000 genes. To date, however, 12% of its genes actually have known biochemical roles. In this study, we considered it instructive to identify the gene expression patterns of nine (so-called AtCAD1-9) of 17 genes originally annotated by The Arabidopsis Information Resource (TAIR) as cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195) homologues [see Costa, M.A., Collins, R.E., Anterola, A.M., Cochrane, F.C., Davin, L.B., Lewis N.G., 2003. An in silico assessment of gene function and organization of the phenylpropanoid pathway metabolic networks in Arabidopsis thaliana and limitations thereof. Phytochemistry 64, 1097-1112.]. In agreement with our biochemical studies in vitro [Kim, S.-J., Kim, M.-R., Bedgar, D.L., Moinuddin, S.G.A., Cardenas, C.L., Davin, L.B., Kang, C.-H., Lewis, N.G., 2004. Functional reclassification of the putative cinnamyl alcohol dehydrogenase multigene family in Arabidopsis. Proc. Natl. Acad. Sci. USA 101, 1455-1460.], and analysis of a double mutant [Sibout, R., Eudes, A., Mouille, G., Pollet, B., Lapierre, C., Jouanin, L., Séguin A., 2005. Cinnamyl Alcohol Dehydrogenase-C and -D are the primary genes involved in lignin biosynthesis in the floral stem of Arabidopsis. Plant Cell 17, 2059-2076.], both AtCAD5 (At4g34230) and AtCAD4 (At3g19450) were found to have expression patterns consistent with development/formation of different forms of the lignified vascular apparatus, e.g. lignifying stem tissues, bases of trichomes, hydathodes, abscission zones of siliques, etc. Expression was also observed in various non-lignifying zones (e.g. root caps) indicative of, perhaps, a role in plant defense. In addition, expression patterns of the four CAD-like homologues were investigated, i.e. AtCAD2 (At2g21730), AtCAD3 (At2g21890), AtCAD7 (At4g37980) and AtCAD8 (At4g37990), each of which previously had been demonstrated to have low CAD

  12. Carbon Costs of Constitutive and Expressed Resistance to a Non-Native Pathogen in Limber Pine.

    Directory of Open Access Journals (Sweden)

    Patrick J Vogan

    Full Text Available Increasing the frequency of resistance to the non-native fungus Cronartium ribicola (causative agent of white pine blister rust, WPBR in limber pine populations is a primary management objective to sustain high-elevation forest communities. However, it is not known to what extent genetic disease resistance is costly to plant growth or carbon economy. In this study, we measured growth and leaf-level physiology in (1 seedling families from seed trees that have previously been inferred to carry or not carry Cr4, the dominant R gene allele conferring complete, gene-for-gene resistance to WPBR in limber pine, and (2 populations that were and were not infected with C. ribicola. We found that, in the absence of C. ribicola exposure, there was no significant difference in carbon relations between families born from seed trees that harbor the resistance allele compared to those that lack it, either to plant growth and phenology or leaf-level photosynthetic traits. However, post-infection with C. ribicola, growth was significantly reduced in inoculation survivors expressing complete resistance compared to uninoculated seedlings. Furthermore, inoculation survivors exhibited significant increases in a suite of traits including photosynthetic rate, respiration rate, leaf N, and stomatal conductance and a decrease in photosynthetic water-use efficiency. The lack of constitutive carbon costs associated with Cr4 resistance in non-stressed limber pine is consistent with a previous report that the R gene allele is not under selection in the absence of C. ribicola and suggests that host resistance may not bear a constitutive cost in pathosystems that have not coevolved. However, under challenge by C. ribicola, complete resistance to WPBR in limber pine has a significant cost to plant growth, though enhanced carbon acquisition post-infection may offset this somewhat. These costs and effects on performance further complicate predictions of this species' response in

  13. AtMRP6/AtABCC6, an ATP-Binding Cassette transporter gene expressed during early steps of seedling development and up-regulated by cadmium in Arabidopsis thaliana

    Science.gov (United States)

    Gaillard, Stéphane; Jacquet, Hélène; Vavasseur, Alain; Leonhardt, Nathalie; Forestier, Cyrille

    2008-01-01

    Background ABC proteins constitute one of the largest families of transporters found in all living organisms. In Arabidopsis thaliana, 120 genes encoding ABC transporters have been identified. Here, the characterization of one member of the MRP subclass, AtMRP6, is described. Results This gene, located on chromosome 3, is bordered by AtMRP3 and AtMRP7. Using real-time quantitative PCR (RT-Q-PCR) and the GUS reporter gene, we found that this gene is essentially expressed during early seedling development, in the apical meristem and at initiation point of secondary roots, especially in xylem-opposite pericycle cells where lateral roots initiate. The level of expression of AtMRP6 in response to various stresses was explored and a significant up-regulation after cadmium (Cd) treatment was detected. Among the three T-DNA insertion lines available from the Salk Institute library, two knock-out mutants, Atmrp6.1 and Atmrp6.2 were invalidated for the AtMRP6 gene. In the presence of Cd, development of leaves was more affected in the mutants than wild-type plants, whereas root elongation and ramification was comparable. Conclusion The position of AtMRP6 on chromosome 3, flanked by two other MRP genes, (all of which being induced by Cd) suggests that AtMRP6 is part of a cluster involved in metal tolerance, although additional functions in planta cannot be discarded. PMID:18307782

  14. Blue light alters miR167 expression and microRNA-targeted auxin response factor genes in Arabidopsis thaliana plants.

    Science.gov (United States)

    Pashkovskiy, Pavel P; Kartashov, Alexander V; Zlobin, Ilya E; Pogosyan, Sergei I; Kuznetsov, Vladimir V

    2016-07-01

    The effect of blue LED (450 nm) on the photomorphogenesis of Arabidopsis thaliana Col-0 plants and the transcript levels of several genes, including miRNAs, photoreceptors and auxin response factors (ARF) was investigated. It was observed that blue light accelerated the generative development, reduced the rosette leaf number, significantly reduced the leaf area, dry biomass and led to the disruption of conductive tissue formation. The blue LED differentially influenced the transcript levels of several phytochromes (PHY a, b, c, d, and e), cryptochromes (CRY 1 and 2) and phototropins (PHOT 1 and 2). At the same time, the blue LED significantly increased miR167 expression compared to a fluorescent lamp or white LEDs. This increase likely resulted in the enhanced transcription of the auxin response factor genes ARF4 and ARF8, which are regulated by this miRNA. These findings support the hypothesis that the effects of blue light on A. thaliana are mediated by auxin signalling pathway involving miRNA-dependent regulation of ARF gene expression. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. Two Silene vulgaris copper transporters residing in different cellular compartments confer copper hypertolerance by distinct mechanisms when expressed in Arabidopsis thaliana.

    Science.gov (United States)

    Li, Yanbang; Iqbal, Mazhar; Zhang, Qianqian; Spelt, Cornelis; Bliek, Mattijs; Hakvoort, Henk W J; Quattrocchio, Francesca M; Koes, Ronald; Schat, Henk

    2017-08-01

    Silene vulgaris is a metallophyte of calamine, cupriferous and serpentine soils all over Europe. Its metallicolous populations are hypertolerant to zinc (Zn), cadmium (Cd), copper (Cu) or nickel (Ni), compared with conspecific nonmetallicolous populations. These hypertolerances are metal-specific, but the underlying mechanisms are poorly understood. We investigated the role of HMA5 copper transporters in Cu-hypertolerance of a S. vulgaris copper mine population. Cu-hypertolerance in Silene is correlated and genetically linked with enhanced expression of two HMA5 paralogs, SvHMA5I and SvHMA5II, each of which increases Cu tolerance when expressed in Arabidopsis thaliana. Most Spermatophytes, except Brassicaceae, possess homologs of SvHMA5I and SvHMA5II, which originate from an ancient duplication predating the appearance of spermatophytes. SvHMA5II and the A. thaliana homolog AtHMA5 localize in the endoplasmic reticulum and upon Cu exposure move to the plasma membrane, from where they are internalized and degraded in the vacuole. This resembles trafficking of mammalian homologs and is apparently an extremely ancient mechanism. SvHMA5I, instead, neofunctionalized and always resides on the tonoplast, likely sequestering Cu in the vacuole. Adaption of Silene to a Cu-polluted soil is at least in part due to upregulation of two distinct HMA5 transporters, which contribute to Cu hypertolerance by distinct mechanisms. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  16. Functional characterization of a heterologously expressed Brassica napus WRKY41-1 transcription factor in regulating anthocyanin biosynthesis in Arabidopsis thaliana.

    Science.gov (United States)

    Duan, Shaowei; Wang, Jianjun; Gao, Chenhao; Jin, Changyu; Li, Dong; Peng, Danshuai; Du, Guomei; Li, Yiqian; Chen, Mingxun

    2018-03-01

    Previous studies have shown that a plant WRKY transcription factor, WRKY41, has multiple functions, and regulates seed dormancy, hormone signaling pathways, and both biotic and abiotic stress responses. However, it is not known about the roles of AtWRKY41 from the model plant, Arabidopsis thaliana, and its ortholog, BnWRKY41, from the closely related and important oil-producing crop, Brassica napus, in the regulation of anthocyanin biosynthesis. Here, we found that the wrky41 mutation in A. thaliana resulted in a significant increase in anthocyanin levels in rosette leaves, indicating that AtWRKY41 acts as repressor of anthocyanin biosynthesis. RNA sequencing and quantitative real-time PCR analysis revealed increased expression of three regulatory genes AtMYB75, AtMYB111, and AtMYBD, and two structural genes, AT1G68440 and AtGSTF12, all of which contribute to anthocyanin biosynthesis, in the sixth rosette leaves of wrky41-2 plants at 20 days after germination. We cloned the full length complementary DNA of BnWRKY41-1 from the C2 subgenome of the B. napus genotype Westar and observed that, when overexpressed in tobacco leaves as a fusion protein with green fluorescent protein, BnWRKY41-1 is localized to the nucleus. We further showed that overexpression of BnWRKY41-1 in the A. thaliana wrky41-2 mutant rescued the higher anthocyanin content phenotype in rosette leaves of the mutant. Moreover, the elevated expression levels in wrky41-2 rosette leaves of several important regulatory and structural genes regulating anthocyanin biosynthesis were not observed in the BnWRKY41-1 overexpressing lines. These results reveal that BnWRKY41-1 has a similar role with AtWRKY41 in regulating anthocyanin biosynthesis when overexpressed in A. thaliana. This gene represents a promising target for genetically manipulating B. napus to increase the amounts of anthocyanins in rosette leaves. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Functional loss of GABA transaminase (GABA-T) expressed early leaf senescence under various stress conditions in Arabidopsis thaliana

    OpenAIRE

    Jalil, Syed Uzma; Ahmad, Iqbal; Ansari, Mohammad Israil

    2017-01-01

    GABA-transaminase (GABA-T) involved in carbon and nitrogen metabolism during the plant development process via GABA shunt and GABA-T mutant, which is defective in GABA catabolism, is ideal model to examine the role of GABA-T in plant development and leaf senescence of plant. We have characterized GABA transaminase knock out mutant pop2-1 that is transition and pop2-3 which is T-DNA insertion mutant of Arabidopsis thaliana during various stress conditions.The GABA-T knockout mutant plants disp...

  18. Loss of constitutive ABCB1 expression in breast cancer associated with worse prognosis

    Directory of Open Access Journals (Sweden)

    Delou JM

    2017-06-01

    histopathological variables was also evaluated. The Kaplan–Meier curves and multivariate Cox regression analyses were conducted to identify independent predictors of disease-free survival of patients with breast cancer. ABCB1 was detected in 86.3% (656 of breast tumors, 98.8% (606 of nonmalignant mammary tissue adjacent to tumors, and 100% (28 of benign lesions. Reduced ABCB1 protein levels in breast tumors was associated with triple-negative subtype (adjusted odds ratio [ORadj] =0.24; 95% confidence interval [CI] =0.13–0.45, lymph node status < pN2 (ORadj =0.27; 95% CI =0.10–0.71, tumor size >2 cm (ORadj =0.55; 95% CI =0.32–0.93, and hypertensive status (ORadj =0.42; 95% CI =0.24–0.73, and it was significantly associated with shorter disease-free survival, either for all breast cancer patients (p log-rank =0.012; hazard ratio [HR] =3.46; 95% CI =1.21–9.91 or for those with triple-negative tumors (p log-rank =0.007; HR =11.41; 95% CI =1.29–100.67. The loss of constitutive ABCB1 expression in breast cancer, especially in triple-negative tumors, seems to indicate a subgroup of worse prognosis. Keywords: multidrug resistance, single-nucleotide polymorphisms, immunohistochemistry, disease-free survival, triple-negative breast cancer, hypertension

  19. Interferon beta 1, an intermediate in the tumor necrosis factor alpha- induced increased MHC class I expression and an autocrine regulator of the constitutive MHC class I expression

    OpenAIRE

    1987-01-01

    In conclusion, our observations indicate that the constitutive MHC class I expression is regulated by autocrine production of IFN-beta 1. TNF-alpha acts as an enhancer of the autocrine production of IFN-beta 1, and consequently as an enhancer of the MHC class I expression and viral protection.

  20. Functional loss of GABA transaminase (GABA-T expressed early leaf senescence under various stress conditions in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Syed Uzma Jalil

    2017-06-01

    Full Text Available GABA-transaminase (GABA-T involved in carbon and nitrogen metabolism during the plant development process via GABA shunt and GABA-T mutant, which is defective in GABA catabolism, is ideal model to examine the role of GABA-T in plant development and leaf senescence of plant. We have characterized GABA transaminase knock out mutant pop2-1 that is transition and pop2-3 which is T-DNA insertion mutant of Arabidopsis thaliana during various stress conditions.The GABA-T knockout mutant plants displayed precocious leaf senescence, which was accompanied by the assays of physiological parameters of leaf senescence during various stress conditions. Furthermore, our physiological evidence indicates that pop2-1 and pop2-3 mutations rapidly decreased the efficiency of leaf photosynthesis, chlorophyll content, GABA content, GABA-T, and glutamate decarboxylase (GAD activity and on the other hand increases membrane ion leakage, malondialdehyde (MDA level in stress induced leaves. However, cell viability assay by trypan blue and insitu Hydrogen peroxidation assay by 3,3-diaminobenzidine (DAB in stress induced leaves also display that pop2-1 and pop2-3 mutant leaves show oversensitivity in response to different stress conditions as compared to wild type. These results strongly indicate that the loss-of-function of GABA transaminase gene induces early leaf senescence in Arabidopsis thaliana during various stress conditions.

  1. Phytoremediation of arsenic from the contaminated soil using transgenic tobacco plants expressing ACR2 gene of Arabidopsis thaliana.

    Science.gov (United States)

    Nahar, Noor; Rahman, Aminur; Nawani, Neelu N; Ghosh, Sibdas; Mandal, Abul

    2017-11-01

    We have cloned, characterized and transformed the AtACR2 gene (arsenic reductase 2) of Arabidopsis thaliana into the genome of tobacco (Nicotiana tabacum, var Sumsun). Our results revealed that the transgenic tobacco plants are more tolerant to arsenic than the wild type ones. These plants can grow on culture medium containing 200μM arsenate, whereas the wild type can barely survive under this condition. Furthermore, when exposed to 100μM arsenate for 35days the amount of arsenic accumulated in the shoots of transgenic plants was significantly lower (28μg/g d wt.) than that found in the shoots of non-transgenic controls (40μg/g d wt.). However, the arsenic content in the roots of transgenic plants was significantly higher (2400μg/g d. wt.) than that (2100μg/g d. wt.) observed in roots of wild type plants. We have demonstrated that Arabidopsis thaliana AtACR2 gene is a potential candidate for genetic engineering of plants to develop new crop cultivars that can be grown on arsenic contaminated fields to reduce arsenic content of the soil and can become a source of food containing no arsenic or exhibiting substantially reduced amount of this metalloid. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Nanoparticle-specific changes in Arabidopsis thaliana gene expression after exposure to ZnO, TiO2, and fullerene soot

    International Nuclear Information System (INIS)

    Landa, Premysl; Vankova, Radomira; Andrlova, Jana; Hodek, Jan; Marsik, Petr; Storchova, Helena; White, Jason C.; Vanek, Tomas

    2012-01-01

    Highlights: ► Exposure to different nanoparticles resulted in specific changes in gene transcription. ► Nano ZnO caused most dramatic changes in Arabidopsis gene expression. ► Nano ZnO was the most toxic and up-regulated most stress-related genes. ► Fullerene soot caused significant gene expression response – mainly stress-related. ► Nano TiO 2 had weak impact on Arabidopsis gene expression indicating minimal toxicity. - Abstract: The effect of exposure to 100 mg/L zinc oxide (nZnO), fullerene soot (FS) or titanium dioxide (nTiO 2 ) nanoparticles on gene expression in Arabidopsis thaliana roots was studied using microarrays. After 7 d, nZnO, FS, or nTiO 2 exposure resulted in 660 up- and 826 down-regulated genes, 232 up- and 189 down-regulated genes, and 80 up- and 74 down-regulated genes, respectively (expression difference > 2-fold; p[t test] 2 exposure, which resulted in up- and down-regulation of genes involved mainly in responses to biotic and abiotic stimuli. The data clearly indicate that the mechanisms of phytotoxicity are highly nanoparticle dependent despite of a limited overlap in gene expression response.

  3. The promoter of the Arabidopsis thaliana plastocyanin gene contains a far upstream enhancer-like element involved in chloroplast-dependent expression.

    Science.gov (United States)

    Vorst, O; Kock, P; Lever, A; Weterings, B; Weisbeek, P; Smeekens, S

    1993-12-01

    Plastocyanin is part of the photosynthetic electron transport chain in the chloroplast and is encoded in the nucleus. Expression of the Arabidopsis thaliana plastocyanin gene is organ specific: high mRNA levels are observed in young green parts of the plant. Furthermore, expression is dependent on the presence of light and functional chloroplasts. When grown in the presence of norflurazon under white light conditions, resulting in the photo-oxidative destruction of the chloroplast, plastocyanin mRNA levels are strongly reduced. A -1579 to -9 promoter fragment confers light-regulated and chloroplast-dependent expression to the beta-glucuronidase reporter gene in transgenic tobacco plants. This suggests that regulation takes place at the level of transcription. A plastocyanin promoter deletion series ranging from -1579 to -121 which was also tested in tobacco, revealed the presence of a strong positive regulating element (PRE) in the -1579 to -705 region. Deletion of this part of the promoter resulted in a approximately 100-fold reduction of GUS expression as measured in mature leaves. Surprisingly, this enhancer-like element was capable of stimulating transcription from a position downstream of its reporter. Moreover, it could also activate a truncated CaMV 35S promoter. Deletion of this element coincides with the loss of chloroplast-dependency of reporter gene expression, as judged by norflurazon treatment of transgenic seedlings. So, the activity of the PRE itself might depend on the presence of functional chloroplasts.

  4. AthaMap web tools for the analysis of transcriptional and posttranscriptional regulation of gene expression in Arabidopsis thaliana.

    Science.gov (United States)

    Hehl, Reinhard; Bülow, Lorenz

    2014-01-01

    The AthaMap database provides a map of verified and predicted transcription factor (TF) and small RNA-binding sites for the A. thaliana genome. The database can be used for bioinformatic predictions of putative regulatory sites. Several online web tools are available that address specific questions. Starting with the identification of transcription factor-binding sites (TFBS) in any gene of interest, colocalizing TFBS can be identified as well as common TFBS in a set of user-provided genes. Furthermore, genes can be identified that are potentially targeted by specific transcription factors or small inhibitory RNAs. This chapter provides detailed information on how each AthaMap web tool can be used online. Examples on how this database is used to address questions in circadian and diurnal regulation are given. Furthermore, complementary databases and databases that go beyond questions addressed with AthaMap are discussed.

  5. Brassica napusGLABRA3-1 promotes anthocyanin biosynthesis and trichome formation in true leaves when expressed in Arabidopsis thaliana.

    Science.gov (United States)

    Gao, C; Guo, Y; Wang, J; Li, D; Liu, K; Qi, S; Jin, C; Duan, S; Gong, J; Li, Z; Chen, M

    2018-01-01

    Previous studies have shown that GLABRA3 (AtGL3), a bHLH transcription factor, plays essential roles in anthocyanin biosynthesis and trichome formation in Arabidopsis thaliana. However, there have been no such studies of a homologue, BnGL3, from the closely related crop, Brassica napus. Here, we analysed the BnGL3-1 coding domain sequence from the B. napus cultivar QINYOU Seven, identified conserved protein domains and performed a phylogenetic analysis to elucidate its relationship with homologues form a range of plant species. When expressed in tobacco leaves as a fusion protein with green fluorescent protein, BnGL3-1 accumulated in the nucleus, consistent with its predicted function as a transcription factor. Ectopic expression of the BnGL3-1 gene in the A. thaliana gl3-3 mutant resulted in levels of anthocyanins and numbers of trichomes in true leaves that were higher than in wild-type plants. Moreover, overexpression of BnGL3-1 in gl3-3 compensated for the promotion and repression of genes involved in anthocyanin biosynthesis and trichome formation, respectively, that has been reported in gl3-3 young shoots and expanding true leaves. This study provides new insights into GL3 function in anthocyanin biosynthesis and trichome formation in crucifers, and represents a promising target for genetic manipulation of B. napus. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  6. Expression, purification and preliminary X-ray diffraction studies of VERNALIZATION1208–341 from Arabidopsis thaliana

    International Nuclear Information System (INIS)

    King, Gordon; Hill, Justine M.; Martin, Jennifer L.; Mylne, Joshua S.

    2009-01-01

    A C-terminal fragment of VERNALIZATION1 from A. thaliana, a DNA-binding protein required for the acceleration of flowering in response to prolonged cold treatment, was crystallized. X-ray diffraction data were collected to a resolution of 2.1 Å. VERNALIZATION1 (VRN1) is required in the model plant Arabidopsis thaliana for the epigenetic suppression of the floral repressor FLC by prolonged cold treatment. Stable suppression of FLC accelerates flowering, a physiological process known as vernalization. VRN1 is a 341-residue DNA-binding protein that contains two plant-specific B3 domains (B3a and B3b), a putative nuclear localization sequence (NLS) and two putative PEST domains. VRN1 208–341 includes the second B3 domain and a region upstream that is highly conserved in the VRN1 orthologues of other dicotyledonous plants. VRN1 208–341 was crystallized by the hanging-drop method in 0.05 M sodium acetate pH 6.0 containing 1.0 M NaCl and 18%(w/v) PEG 3350. Preliminary X-ray diffraction data analysis revealed that the VRN1 208–341 crystal diffracted to 2.1 Å and belonged to space group C2, with unit-cell parameters a = 105.2, b = 47.9, c = 61.2 Å, α = 90.0, β = 115.4, γ = 90.0°. Assuming that two molecules occupy the asymmetric unit, a Matthews coefficient of 2.05 Å 3 Da −1 and a solvent content of 40.1% were calculated

  7. Overexpression of LOV KELCH protein 2 confers dehydration tolerance and is associated with enhanced expression of dehydration-inducible genes in Arabidopsis thaliana.

    Science.gov (United States)

    Miyazaki, Yuji; Abe, Hiroshi; Takase, Tomoyuki; Kobayashi, Masatomo; Kiyosue, Tomohiro

    2015-05-01

    The overexpression of LKP2 confers dehydration tolerance in Arabidopsis thaliana ; this is likely due to enhanced expression of dehydration-inducible genes and reduced stomatal opening. LOV KELCH protein 2 (LKP2) modulates the circadian rhythm and flowering time in plants. In this study, we observed that LKP2 overexpression enhanced dehydration tolerance in Arabidopsis. Microarray analysis demonstrated that expression of water deprivation-responsive genes was higher in the absence of dehydration stress in transgenic Arabidopsis plants expressing green fluorescent protein-tagged LKP2 (GFP-LKP2) than in control transgenic plants expressing GFP. After dehydration followed by rehydration, GFP-LKP2 plants developed more leaves and roots and exhibited higher survival rates than control plants. In the absence of dehydration stress, four dehydration-inducible genes, namely DREB1A, DREB1B, DREB1C, and RD29A, were expressed in GFP-LKP2 plants, whereas they were not expressed or were expressed at low levels in control plants. Under dehydration stress, the expression of DREB2B and RD29A peaked faster in the GFP-LKP2 plants than in control plants. The stomatal aperture of GFP-LKP2 plants was smaller than that of control plants. These results suggest that the dehydration tolerance of GFP-LKP2 plants is caused by upregulation of DREB1A-C/CBF1-3 and their downstream targets; restricted stomatal opening in the absence of dehydration stress also appears to contribute to the phenotype. The rapid and high expression of DREB2B and its downstream target genes also likely accounts for some features of the GFP-LKP2 phenotype. Our results suggest that LKP2 can be used for biotechnological applications not only to adjust the flowering time control but also to enhance dehydration tolerance.

  8. Identification of reference genes for quantitative expression analysis using large-scale RNA-seq data of Arabidopsis thaliana and model crop plants.

    Science.gov (United States)

    Kudo, Toru; Sasaki, Yohei; Terashima, Shin; Matsuda-Imai, Noriko; Takano, Tomoyuki; Saito, Misa; Kanno, Maasa; Ozaki, Soichi; Suwabe, Keita; Suzuki, Go; Watanabe, Masao; Matsuoka, Makoto; Takayama, Seiji; Yano, Kentaro

    2016-10-13

    In quantitative gene expression analysis, normalization using a reference gene as an internal control is frequently performed for appropriate interpretation of the results. Efforts have been devoted to exploring superior novel reference genes using microarray transcriptomic data and to evaluating commonly used reference genes by targeting analysis. However, because the number of specifically detectable genes is totally dependent on probe design in the microarray analysis, exploration using microarray data may miss some of the best choices for the reference genes. Recently emerging RNA sequencing (RNA-seq) provides an ideal resource for comprehensive exploration of reference genes since this method is capable of detecting all expressed genes, in principle including even unknown genes. We report the results of a comprehensive exploration of reference genes using public RNA-seq data from plants such as Arabidopsis thaliana (Arabidopsis), Glycine max (soybean), Solanum lycopersicum (tomato) and Oryza sativa (rice). To select reference genes suitable for the broadest experimental conditions possible, candidates were surveyed by the following four steps: (1) evaluation of the basal expression level of each gene in each experiment; (2) evaluation of the expression stability of each gene in each experiment; (3) evaluation of the expression stability of each gene across the experiments; and (4) selection of top-ranked genes, after ranking according to the number of experiments in which the gene was expressed stably. Employing this procedure, 13, 10, 12 and 21 top candidates for reference genes were proposed in Arabidopsis, soybean, tomato and rice, respectively. Microarray expression data confirmed that the expression of the proposed reference genes under broad experimental conditions was more stable than that of commonly used reference genes. These novel reference genes will be useful for analyzing gene expression profiles across experiments carried out under various

  9. Enhancement of Chlorogenic Acid Production in Hairy Roots of Platycodon grandiflorum by Over-Expression of An Arabidopsis thaliana Transcription Factor AtPAP1

    Directory of Open Access Journals (Sweden)

    Pham Anh Tuan

    2014-08-01

    Full Text Available To improve the production of chlorogenic acid (CGA in hairy roots of Platycodon grandiflorum, we induced over-expression of Arabidopsis thaliana transcription factor production of anthocyanin pigment (AtPAP1 using an Agrobacterium rhizogenes-mediated transformation system. Twelve hairy root lines showing over-expression of AtPAP1 were generated. In order to investigate the regulation of AtPAP1 on the activities of CGA biosynthetic genes, the expression levels of seven P. grandiflorum CGA biosynthetic genes were analyzed in the hairy root line that had the greatest accumulation of AtPAP1 transcript, OxPAP1-1. The introduction of AtPAP1 increased the mRNA levels of all examined CGA biosynthetic genes and resulted in a 900% up-regulation of CGA accumulation in OxPAP1-1 hairy roots relative to controls. This suggests that P. grandiflorum hairy roots that over-express the AtPAP1 gene are a potential alternative source of roots for the production of CGA.

  10. Engineering of red cells of Arabidopsis thaliana and comparative genome-wide gene expression analysis of red cells versus wild-type cells.

    Science.gov (United States)

    Shi, Ming-Zhu; Xie, De-Yu

    2011-04-01

    We report metabolic engineering of Arabidopsis red cells and genome-wide gene expression analysis associated with anthocyanin biosynthesis and other metabolic pathways between red cells and wild-type (WT) cells. Red cells of A. thaliana were engineered for the first time from the leaves of production of anthocyanin pigment 1-Dominant (pap1-D). These red cells produced seven anthocyanin molecules including a new one that was characterized by LC-MS analysis. Wild-type cells established as a control did not produce anthocyanins. A genome-wide microarray analysis revealed that nearly 66 and 65% of genes in the genome were expressed in the red cells and wild-type cells, respectively. In comparison with the WT cells, 3.2% of expressed genes in the red cells were differentially expressed. The expression levels of 14 genes involved in the biosynthetic pathway of anthocyanin were significantly higher in the red cells than in the WT cells. Microarray and RT-PCR analyses demonstrated that the TTG1-GL3/TT8-PAP1 complex regulated the biosynthesis of anthocyanins. Furthermore, most of the genes with significant differential expression levels in the red cells versus the WT cells were characterized with diverse biochemical functions, many of which were mapped to different metabolic pathways (e.g., ribosomal protein biosynthesis, photosynthesis, glycolysis, glyoxylate metabolism, and plant secondary metabolisms) or organelles (e.g., chloroplast). We suggest that the difference in gene expression profiles between the two cell lines likely results from cell types, the overexpression of PAP1, and the high metabolic flux toward anthocyanins.

  11. Nanoparticle-specific changes in Arabidopsis thaliana gene expression after exposure to ZnO, TiO{sub 2}, and fullerene soot

    Energy Technology Data Exchange (ETDEWEB)

    Landa, Premysl [Laboratory of Plant Biotechnologies, Institute of Experimental Botany AS CR, v.v.i., 165 02 Prague 6 - Lysolaje (Czech Republic); Vankova, Radomira [Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany AS CR, v.v.i., 165 02 Prague 6 - Lysolaje (Czech Republic); Andrlova, Jana [Laboratory of Plant Biotechnologies, Institute of Experimental Botany AS CR, v.v.i., 165 02 Prague 6 - Lysolaje (Czech Republic); Department of Crop Sciences and Agroforestry, Institute of Tropics and Subtropics, Czech University of Life Sciences Prague, 165 21 Prague 6 - Suchdol (Czech Republic); Hodek, Jan [Department of Molecular Biology, Crop Research Institute, v.v.i., 161 06 Praha 6 - Ruzyne (Czech Republic); Marsik, Petr [Laboratory of Plant Biotechnologies, Institute of Experimental Botany AS CR, v.v.i., 165 02 Prague 6 - Lysolaje (Czech Republic); Storchova, Helena [Plant Reproduction Laboratory, Institute of Experimental Botany AS CR, v.v.i., 165 02 Prague 6 - Lysolaje (Czech Republic); White, Jason C. [Department of Analytical Chemistry, Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06512 (United States); Vanek, Tomas, E-mail: vanek@ueb.cas.cz [Laboratory of Plant Biotechnologies, Institute of Experimental Botany AS CR, v.v.i., 165 02 Prague 6 - Lysolaje (Czech Republic)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Exposure to different nanoparticles resulted in specific changes in gene transcription. Black-Right-Pointing-Pointer Nano ZnO caused most dramatic changes in Arabidopsis gene expression. Black-Right-Pointing-Pointer Nano ZnO was the most toxic and up-regulated most stress-related genes. Black-Right-Pointing-Pointer Fullerene soot caused significant gene expression response - mainly stress-related. Black-Right-Pointing-Pointer Nano TiO{sub 2} had weak impact on Arabidopsis gene expression indicating minimal toxicity. - Abstract: The effect of exposure to 100 mg/L zinc oxide (nZnO), fullerene soot (FS) or titanium dioxide (nTiO{sub 2}) nanoparticles on gene expression in Arabidopsis thaliana roots was studied using microarrays. After 7 d, nZnO, FS, or nTiO{sub 2} exposure resulted in 660 up- and 826 down-regulated genes, 232 up- and 189 down-regulated genes, and 80 up- and 74 down-regulated genes, respectively (expression difference > 2-fold; p[t test] < 0.05). The genes induced by nZnO and FS include mainly ontology groups annotated as stress responsive, including both abiotic (oxidative, salt, water deprivation) and biotic (wounding and defense to pathogens) stimuli. The down-regulated genes upon nZnO exposure were involved in cell organization and biogenesis, including translation, nucleosome assembly and microtubule based process. FS largely repressed the transcription of genes involved in electron transport and energy pathways. Only mild changes in gene expression were observed upon nTiO{sub 2} exposure, which resulted in up- and down-regulation of genes involved mainly in responses to biotic and abiotic stimuli. The data clearly indicate that the mechanisms of phytotoxicity are highly nanoparticle dependent despite of a limited overlap in gene expression response.

  12. Expression of transcription factors after short-term exposure of Arabidopsis thaliana cell cultures to hypergravity and simulated microgravity (2-D/3-D clinorotation, magnetic levitation)

    Science.gov (United States)

    Babbick, M.; Dijkstra, C.; Larkin, O. J.; Anthony, P.; Davey, M. R.; Power, J. B.; Lowe, K. C.; Cogoli-Greuter, M.; Hampp, R.

    Gravity is an important environmental factor that controls plant growth and development. Studies have shown that the perception of gravity is not only a property of specialized cells, but can also be performed by undifferentiated cultured cells. In this investigation, callus of Arabidopsis thaliana cv. Columbia was used to investigate the initial steps of gravity-related signalling cascades, through altered expression of transcription factors (TFs). TFs are families of small proteins that regulate gene expression by binding to specific promoter sequences. Based on microarray studies, members of the gene families WRKY, MADS-box, MYB, and AP2/EREBP were selected for investigation, as well as members of signalling chains, namely IAA 19 and phosphoinositol-4-kinase. Using qRT-PCR, transcripts were quantified within a period of 30 min in response to hypergravity (8 g), clinorotation [2-D clinostat and 3-D random positioning machine (RPM)] and magnetic levitation (ML). The data indicated that (1) changes in gravity induced stress-related signalling, and (2) exposure in the RPM induced changes in gene expression which resemble those of magnetic levitation. Two dimensional clinorotation resulted in responses similar to those caused by hypergravity. It is suggested that RPM and ML are preferable to simulate microgravity than clinorotation.

  13. Arabidopsis thaliana plants expressing Rift Valley fever virus antigens: Mice exhibit systemic immune responses as the result of oral administration of the transgenic plants.

    Science.gov (United States)

    Kalbina, Irina; Lagerqvist, Nina; Moiane, Bélisario; Ahlm, Clas; Andersson, Sören; Strid, Åke; Falk, Kerstin I

    2016-11-01

    The zoonotic Rift Valley fever virus affects livestock and humans in Africa and on the Arabian Peninsula. The economic impact of this pathogen due to livestock losses, as well as its relevance to public health, underscores the importance of developing effective and easily distributed vaccines. Vaccines that can be delivered orally are of particular interest. Here, we report the expression in transformed plants (Arabidopsis thaliana) of Rift Valley fever virus antigens. The antigens used in this study were the N protein and a deletion mutant of the Gn glycoprotein. Transformed lines were analysed for specific mRNA and protein content by RT-PCR and Western blotting, respectively. Furthermore, the plant-expressed antigens were evaluated for their immunogenicity in mice fed the transgenic plants. After oral intake of fresh transgenic plant material, a proportion of the mice elicited specific IgG antibody responses, as compared to the control animals that were fed wild-type plants and of which none sero-converted. Thus, we show that transgenic plants can be readily used to express and produce Rift Valley Fever virus proteins, and that the plants are immunogenic when given orally to mice. These are promising findings and provide a basis for further studies on edible plant vaccines against the Rift Valley fever virus. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Ectopic expression of ubiquitin-conjugating enzyme gene from wild rice, OgUBC1, confers resistance against UV-B radiation and Botrytis infection in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Jeon, En Hee; Pak, Jung Hun; Kim, Mi Jin; Kim, Hye Jeong; Shin, Sang Hyun; Lee, Jai Heon; Kim, Doh Hoon; Oh, Ju Sung; Oh, Boung-Jun; Jung, Ho Won; Chung, Young Soo

    2012-01-01

    Highlights: ► We isolated a novel E2 ubiquitin-conjugating enzyme from leaves of wild rice plants. ► The OgUBC1 was highly expressed in leaves treated with SA and UV-B radiation. ► The recombinant OgUBC1 has an enzymatic activity of E2 in vitro. ► The OgUBC1 could protect disruption of plant cells by UV-B radiation. ► OgUBC1 confers disease resistance and UV-B tolerance in transgenic Arabidopsis plants. -- Abstract: A previously unidentified gene encoding ubiquitin-conjugating enzyme was isolated from leaves of wild rice plant treated with wounding and microbe-associated molecular patterns. The OgUBC1 gene was composed of 148 amino acids and contained a typical active site and 21 ubiquitin thioester intermediate interaction residues and 4 E3 interaction residues. Both exogenous application of salicylic acid and UV-B irradiation triggered expression of OgUBC1 in leaves of wild rice. Recombinant OgUBC1 proteins bound to ubiquitins in vitro, proposing that the protein might act as E2 enzyme in planta. Heterologous expression of the OgUBC1 in Arabidopsis thaliana protected plants from cellular damage caused by an excess of UV-B radiation. A stable expression of chalcone synthase gene was detected in leaves of OgUBC1-expressing Arabidopsis, resulting in producing higher amounts of anthocyanin than those in wild-type Col-0 plants. Additionally, both pathogenesis-related gene1 and 5 were transcribed in the transgenic Arabidopsis in the absence of pathogen infection. The OgUBC1-expressing plants were resistant to the infection of Botrytis cinerea. Taken together, we suggested that the OgUBC1 is involved in ubiquitination process important for cellular response against biotic and abiotic stresses in plants.

  15. Ectopic expression of ubiquitin-conjugating enzyme gene from wild rice, OgUBC1, confers resistance against UV-B radiation and Botrytis infection in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, En Hee; Pak, Jung Hun; Kim, Mi Jin; Kim, Hye Jeong [Department of Genetic Engineering, Dong-A University, Busan 604-714 (Korea, Republic of); Shin, Sang Hyun [National Crop Experiment Station, Rural Development Administration, Suwon 441-100 (Korea, Republic of); Lee, Jai Heon; Kim, Doh Hoon; Oh, Ju Sung [Department of Genetic Engineering, Dong-A University, Busan 604-714 (Korea, Republic of); Oh, Boung-Jun [BioControl Center, Jeonnam 516-942 (Korea, Republic of); Jung, Ho Won, E-mail: hwjung@dau.ac.kr [Department of Genetic Engineering, Dong-A University, Busan 604-714 (Korea, Republic of); Chung, Young Soo, E-mail: chungys@dau.ac.kr [Department of Genetic Engineering, Dong-A University, Busan 604-714 (Korea, Republic of)

    2012-10-19

    Highlights: Black-Right-Pointing-Pointer We isolated a novel E2 ubiquitin-conjugating enzyme from leaves of wild rice plants. Black-Right-Pointing-Pointer The OgUBC1 was highly expressed in leaves treated with SA and UV-B radiation. Black-Right-Pointing-Pointer The recombinant OgUBC1 has an enzymatic activity of E2 in vitro. Black-Right-Pointing-Pointer The OgUBC1 could protect disruption of plant cells by UV-B radiation. Black-Right-Pointing-Pointer OgUBC1 confers disease resistance and UV-B tolerance in transgenic Arabidopsis plants. -- Abstract: A previously unidentified gene encoding ubiquitin-conjugating enzyme was isolated from leaves of wild rice plant treated with wounding and microbe-associated molecular patterns. The OgUBC1 gene was composed of 148 amino acids and contained a typical active site and 21 ubiquitin thioester intermediate interaction residues and 4 E3 interaction residues. Both exogenous application of salicylic acid and UV-B irradiation triggered expression of OgUBC1 in leaves of wild rice. Recombinant OgUBC1 proteins bound to ubiquitins in vitro, proposing that the protein might act as E2 enzyme in planta. Heterologous expression of the OgUBC1 in Arabidopsis thaliana protected plants from cellular damage caused by an excess of UV-B radiation. A stable expression of chalcone synthase gene was detected in leaves of OgUBC1-expressing Arabidopsis, resulting in producing higher amounts of anthocyanin than those in wild-type Col-0 plants. Additionally, both pathogenesis-related gene1 and 5 were transcribed in the transgenic Arabidopsis in the absence of pathogen infection. The OgUBC1-expressing plants were resistant to the infection of Botrytis cinerea. Taken together, we suggested that the OgUBC1 is involved in ubiquitination process important for cellular response against biotic and abiotic stresses in plants.

  16. Ectopic phytocystatin expression leads to enhanced drought stress tolerance in soybean (Glycine max) and Arabidopsis thaliana through effects on strigolactone pathways and can also result in improved seed traits.

    Science.gov (United States)

    Quain, Marian D; Makgopa, Matome E; Márquez-García, Belén; Comadira, Gloria; Fernandez-Garcia, Nieves; Olmos, Enrique; Schnaubelt, Daniel; Kunert, Karl J; Foyer, Christine H

    2014-09-01

    Ectopic cystatin expression has long been used in plant pest management, but the cysteine protease, targets of these inhibitors, might also have important functions in the control of plant lifespan and stress tolerance that remain poorly characterized. We therefore characterized the effects of expression of the rice cystatin, oryzacystatin-I (OCI), on the growth, development and stress tolerance of crop (soybean) and model (Arabidopsis thaliana) plants. Ectopic OCI expression in soybean enhanced shoot branching and leaf chlorophyll accumulation at later stages of vegetative development and enhanced seed protein contents and decreased the abundance of mRNAs encoding strigolactone synthesis enzymes. The OCI-expressing A. thaliana showed a slow-growth phenotype, with increased leaf numbers and enhanced shoot branching at flowering. The OCI-dependent inhibition of cysteine proteases enhanced drought tolerance in soybean and A. thaliana, photosynthetic CO2 assimilation being much less sensitive to drought-induced inhibition in the OCI-expressing soybean lines. Ectopic OCI expression or treatment with the cysteine protease inhibitor E64 increased lateral root densities in A. thaliana. E64 treatment also increased lateral root densities in the max2-1 mutants that are defective in strigolactone signalling, but not in the max3-9 mutants that are defective in strigolactone synthesis. Taken together, these data provide evidence that OCI-inhibited cysteine proteases participate in the control of growth and stress tolerance through effects on strigolactones. We conclude that cysteine proteases are important targets for manipulation of plant growth, development and stress tolerance, and also seed quality traits. © 2014 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  17. Expression, crystallization and preliminary X-ray diffraction analysis of the CMM2 region of the Arabidopsis thaliana Morpheus’ molecule 1 protein

    International Nuclear Information System (INIS)

    Petty, Tom J.; Nishimura, Taisuke; Emamzadah, Soheila; Gabus, Caroline; Paszkowski, Jerzy; Halazonetis, Thanos D.; Thore, Stéphane

    2010-01-01

    In order to investigate its function in transcriptional gene silencing, the highly conserved motif 2 from A. thaliana Morpheus’ molecule 1 protein was expressed, purified and crystallized. X-ray diffraction analysis is reported to a resolution of 3.2 Å. Of the known epigenetic control regulators found in plants, the Morpheus’ molecule 1 (MOM1) protein is atypical in that the deletion of MOM1 does not affect the level of epigenetic marks controlling the transcriptional status of the genome. A short 197-amino-acid fragment of the MOM1 protein sequence can complement MOM1 deletion when coupled to a nuclear localization signal, suggesting that this region contains a functional domain that compensates for the loss of the full-length protein. Numerous constructs centred on the highly conserved MOM1 motif 2 (CMM2) present in these 197 residues have been generated and expressed in Escherichia coli. Following purification and crystallization screening, diamond-shaped single crystals were obtained that diffracted to ∼3.2 Å resolution. They belonged to the trigonal space group P3 1 21 (or P3 2 21), with unit-cell parameters a = 85.64, c = 292.74 Å. Structure determination is ongoing

  18. Over-expression of Arabidopsis thaliana SFD1/GLY1, the gene encoding plastid localized glycerol-3-phosphate dehydrogenase, increases plastidic lipid content in transgenic rice plants.

    Science.gov (United States)

    Singh, Vijayata; Singh, Praveen Kumar; Siddiqui, Adnan; Singh, Subaran; Banday, Zeeshan Zahoor; Nandi, Ashis Kumar

    2016-03-01

    Lipids are the major constituents of all membranous structures in plants. Plants possess two pathways for lipid biosynthesis: the prokaryotic pathway (i.e., plastidic pathway) and the eukaryotic pathway (i.e., endoplasmic-reticulum (ER) pathway). Whereas some plants synthesize galactolipids from diacylglycerol assembled in the plastid, others, including rice, derive their galactolipids from diacylglycerols assembled by the eukaryotic pathway. Arabidopsis thaliana glycerol-3-phosphate dehydrogenase (G3pDH), coded by SUPPRESSOR OF FATTY ACID DESATURASE 1 (SFD1; alias GLY1) gene, catalyzes the formation of glycerol 3-phosphate (G3p), the backbone of many membrane lipids. Here SFD1 was introduced to rice as a transgene. Arabidopsis SFD1 localizes in rice plastids and its over-expression increases plastidic membrane lipid content in transgenic rice plants without any major impact on ER lipids. The results suggest that over-expression of plastidic G3pDH enhances biosynthesis of plastid-localized lipids in rice. Lipid composition in the transgenic plants is consistent with increased phosphatidylglycerol synthesis in the plastid and increased galactolipid synthesis from diacylglycerol produced via the ER pathway. The transgenic plants show a higher photosynthetic assimilation rate, suggesting a possible application of this finding in crop improvement.

  19. Constitutive expression of nitrate reductase allows normal growth and development of Nicotiana plumbaginifolia plants.

    Science.gov (United States)

    Vincentz, M; Caboche, M

    1991-01-01

    A nitrate reductase (NR) deficient mutant of Nicotiana plumbaginifolia totally impaired in the production of NR transcript and protein was restored for NR activity by transformation with a chimaeric NR gene. This gene was composed of a full-length tobacco NR cDNA fused to the CaMV 35S promoter and to termination signals from the tobacco NR gene. The transgenic plants we obtained were viable and fertile and expressed from one-fifth to three times the wild-type NR activity in their leaves. The analysis of chimeric NR gene expression in these plants showed, by comparison with wild-type plants, that the regulation of NR gene expression by light, nitrate and circadian rhythm takes place at the transcriptional level. However, unlike nitrate, light was required for the accumulation of NR protein in transgenic plants, suggesting that NR expression is also controlled at the translational and/or post-translational level. Images PMID:2022181

  20. A constitutively expressed antifungal peptide protects Tenebrio molitor during a natural infection by the entomopathogenic fungus Beauveria bassiana.

    Science.gov (United States)

    Maistrou, Sevasti; Paris, Véronique; Jensen, Annette B; Rolff, Jens; Meyling, Nicolai V; Zanchi, Caroline

    2018-09-01

    Antimicrobial peptides have been well studied in the context of bacterial infections. Antifungal peptides have received comparatively less attention. Fungal pathogens of insects and their hosts represent a unique opportunity to study host-pathogen interactions due to the million of years of co-evolution they share. In this study, we investigated role of a constitutively expressed thaumatin-like peptide with antifungal activity expressed by the mealworm beetle Tenebrio molitor, named Tenecin 3, during a natural infection with the entomopathogenic fungus Beauveria bassiana. We monitored the effect of the expression of Tenecin 3 on the survival of infected hosts as well as on the progression of the fungal infection inside the host. Finally, we tested the activity of Tenecin 3 against B. bassiana. These findings could help improving biocontrol strategies and help understanding the evolution of antifungal peptides as a defense mechanism. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Ectopic Expression of the Wild Grape WRKY Transcription Factor VqWRKY52 in Arabidopsis thaliana Enhances Resistance to the Biotrophic Pathogen Powdery Mildew But Not to the Necrotrophic Pathogen Botrytis cinerea.

    Science.gov (United States)

    Wang, Xianhang; Guo, Rongrong; Tu, Mingxing; Wang, Dejun; Guo, Chunlei; Wan, Ran; Li, Zhi; Wang, Xiping

    2017-01-01

    WRKY transcription factors are known to play important roles in plant responses to biotic stresses. We previously showed that the expression of the WRKY gene, VqWRKY52 , from Chinese wild Vitis quinquangularis was strongly induced 24 h post inoculation with powdery mildew. In this study, we analyzed the expression levels of VqWRKY52 following treatment with the defense related hormones salicylic acid (SA) and methyl jasmonate, revealing that VqWRKY52 was strongly induced by SA but not JA. We characterized the VqWRKY52 gene, which encodes a WRKY III gene family member, and found that ectopic expression in Arabidopsis thaliana enhanced resistance to powdery mildew and Pseudomonas syringae pv. tomato DC3000, but increased susceptibility to Botrytis cinerea , compared with wild type (WT) plants. The transgenic A. thaliana lines displayed strong cell death induced by the biotrophic powdery mildew pathogen, the hemibiotrophic P. syringe pathogen and the necrotrophic pathogen B. cinerea . In addition, the relative expression levels of various defense-related genes were compared between the transgenic A. thaliana lines and WT plants following the infection by different pathogens. Collectively, the results indicated that VqWRKY52 plays essential roles in the SA dependent signal transduction pathway and that it can enhance the hypersensitive response cell death triggered by microbial pathogens.

  2. High-level expression, purification and characterization of a constitutively active thromboxane A2 receptor polymorphic variant.

    Directory of Open Access Journals (Sweden)

    Bing Xu

    Full Text Available G protein-coupled receptors (GPCRs exhibit some level of basal signaling even in the absence of a bound agonist. This basal or constitutive signaling can have important pathophysiological roles. In the past few years, a number of high resolution crystal structures of GPCRs have been reported, including two crystal structures of constitutively active mutants (CAM of the dim-light receptor, rhodopsin. The structural characterizations of CAMs are impeded by the lack of proper expression systems. The thromboxane A2 receptor (TP is a GPCR that mediates vasoconstriction and promotes thrombosis in response to the binding of thromboxane. Here, we report on the expression and purification of a genetic variant and CAM in TP, namely A160T, using tetracycline-inducible HEK293S-TetR and HEK293S (GnTI¯-TetR cell lines. Expression of the TP and the A160T genes in these mammalian cell lines resulted in a 4-fold increase in expression to a level of 15.8 ±0.3 pmol of receptor/mg of membrane protein. The receptors expressed in the HEK293S (GnTI(--TetR cell line showed homogeneous glycosylation. The functional yield of the receptors using a single step affinity purification was 45 µg/10⁶ cells. Temperature- dependent secondary structure changes of the purified TP and A160T receptors were characterized using circular dichroism (CD spectropolarimetry. The CD spectra shows that the loss of activity or thermal sensitivity that was previously observed for the A160T mutant, is not owing to large unfolding of the protein but rather to a more subtle effect. This is the first study to report on the successful high-level expression, purification, and biophysical characterization of a naturally occurring, diffusible ligand activated GPCR CAM.

  3. Constitutive expression of pluripotency-associated genes in mesodermal progenitor cells (MPCs.

    Directory of Open Access Journals (Sweden)

    Simone Pacini

    Full Text Available BACKGROUND: We recently characterized a progenitor of mesodermal lineage (MPCs from the human bone marrow of adults or umbilical cord blood. These cells are progenitors able to differentiate toward mesenchymal, endothelial and cardiomyogenic lineages. Here we present an extensive molecular characterization of MPCs, from bone marrow samples, including 39 genes involved in stem cell machinery, differentiation and cell cycle regulation. METHODOLOGY/PRINCIPAL FINDINGS: MPCs are cytofluorimetrically characterized and quantitative RT-PCR was performed to evaluate the gene expression profile, comparing it with MSCs and hESCs lines. Immunofluorescence and dot-blot analysis confirm qRT-PCR data. MPCs exhibit an increased expression of OCT4, NANOG, SALL4, FBX15, SPP1 and to a lesser extent c-MYC and KLF4, but lack LIN28 and SOX2. MPCs highly express SOX15. CONCLUSIONS/SIGNIFICANCE: MPCs express many pluripotency-associated genes and show a peculiar Oct-4 molecular circuit. Understanding this unique molecular mechanism could lead to identifying MPCs as feasible, long telomeres, target cells for reprogramming with no up-regulation of the p53 pathway. Furthermore MPCs are easily and inexpensively harvested from human bone marrow.

  4. Establishment of Sf9 transformants constitutively expressing PBAN receptor variants: application to functional evaluation

    Science.gov (United States)

    To facilitate further evaluation of pheromone biosynthesis activating neuropeptide receptor (PBANR) functionality and regulation, we generated cultured insect cell lines stably expressing a number of fluorescent Bombyx mori PBANR (BommoPBANR) and Pseudaletia separata PBANR (PsesePBANR) variants incl...

  5. Constitutive expression of a costimulatory ligand on antigen-presenting cells in the nervous system drives demyelinating disease

    DEFF Research Database (Denmark)

    Zehntner, Simone P; Brisebois, Marcel; Tran, Elise

    2003-01-01

    that transgenic mice constitutively expressing the costimulatory ligand B7.2/CD86 on microglia in the central nervous system (CNS) and on related cells in the proximal peripheral nervous tissue spontaneously develop autoimmune demyelinating disease. Disease-affected nervous tissue in transgenic mice showed...... recipients but not into non-transgenic recipients. These data provide evidence that B7/CD28 interactions within the nervous tissue are critical determinants of disease development. Our findings have important implications for understanding the etiology of nervous system autoimmune diseases such as multiple...

  6. Transcriptomic and proteomic approach to identify differentially expressed genes and proteins in Arabidopsis thaliana mutants lacking chloroplastic 1 and cytosolic FBPases reveals several levels of metabolic regulation.

    Science.gov (United States)

    Soto-Suárez, Mauricio; Serrato, Antonio J; Rojas-González, José A; Bautista, Rocío; Sahrawy, Mariam

    2016-12-01

    During the photosynthesis, two isoforms of the fructose-1,6-bisphosphatase (FBPase), the chloroplastidial (cFBP1) and the cytosolic (cyFBP), catalyse the first irreversible step during the conversion of triose phosphates (TP) to starch or sucrose, respectively. Deficiency in cyFBP and cFBP1 isoforms provokes an imbalance of the starch/sucrose ratio, causing a dramatic effect on plant development when the plastidial enzyme is lacking. We study the correlation between the transcriptome and proteome profile in rosettes and roots when cFBP1 or cyFBP genes are disrupted in Arabidopsis thaliana knock-out mutants. By using a 70-mer oligonucleotide microarray representing the genome of Arabidopsis we were able to identify 1067 and 1243 genes whose expressions are altered in the rosettes and roots of the cfbp1 mutant respectively; whilst in rosettes and roots of cyfbp mutant 1068 and 1079 genes are being up- or down-regulated respectively. Quantitative real-time PCR validated 100% of a set of 14 selected genes differentially expressed according to our microarray analysis. Two-dimensional (2-D) gel electrophoresis-based proteomic analysis revealed quantitative differences in 36 and 26 proteins regulated in rosettes and roots of cfbp1, respectively, whereas the 18 and 48 others were regulated in rosettes and roots of cyfbp mutant, respectively. The genes differentially expressed and the proteins more or less abundant revealed changes in protein metabolism, RNA regulation, cell signalling and organization, carbon metabolism, redox regulation, and transport together with biotic and abiotic stress. Notably, a significant set (25%) of the proteins identified were also found to be regulated at a transcriptional level. This transcriptomic and proteomic analysis is the first comprehensive and comparative study of the gene/protein re-adjustment that occurs in photosynthetic and non-photosynthetic organs of Arabidopsis mutants lacking FBPase isoforms.

  7. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

    Directory of Open Access Journals (Sweden)

    Nadal Anna

    2012-09-01

    Full Text Available Abstract Background The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER, analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP, had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM

  8. Expression of transcription factors after short-term exposure of Arabidopsis thaliana cell cultures to hyper-g, and to simulated and sounding rocket micro-g

    Science.gov (United States)

    Hampp, R.; Babbick, M.

    Previous microarray studies with cell cultures of Arabidopsis thaliana cv Columbia have shown responses in gene expression which were partly specific to exposure to microgravity sounding rocket experiment TEXUS In order to get access to early responses upon changes in gravitational fields we used exposure times as short as 2 min For this purpose we selected a range of genes which code for different groups of transcription factors WRKY ERF MYB MADS Samples were taken in 5-min clinorotation 2- and 3-dimensional hypergravity 8g and 2-min intervals sounding rocket experiment Amounts of transcripts were determined by quantitative RT PCR Most transcripts showed a significant transient change in content within a time frame of up to 30 min after changing the external gravitational field strength They could be grouped into 1 basic stress responses which occurred under all conditions 2 clinorotation-related effects which were either identical or opposite between 2D 60 rpm 4x10 -2 g and 3D clinorotation random positioning machine and 3 alterations specific to the microgravity exposure under sounding rocket conditions MAXUS The data are discussed in relation to gravitation-dependent signalling chains and with regard to the simulation of microgravity by means of clinorotation Supported by a grant from the Deutsches Zentrum f u r Luft- und Raumfahrt e V grant no 50 WB 0143

  9. Selective lignin downregulation leads to constitutive defense response expression in alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Gallego-Giraldo, Lina; Jikumaru, Yusuke; Kamiya, Yuji; Tang, Yuhong; Dixon, Richard A

    2011-05-01

    • Downregulation of hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) in alfalfa (Medicago sativa) reduces lignin levels and improves forage quality and saccharification efficiency for bioethanol production. However, the plants have reduced stature. It was previously reported that HCT-down-regulated Arabidopsis have impaired auxin transport, but this has recently been disproved. • To address the basis for the phenotypes of lignin-modified alfalfa, we measured auxin transport, profiled a range of metabolites including flavonoids and hormones, and performed in depth transcriptome analyses. • Auxin transport is unaffected in HCT antisense alfalfa despite increased flavonoid biosynthesis. The plants show increased cytokinin and reduced auxin levels, and gibberellin levels and sensitivity are both reduced. Levels of salicylic, jasmonic and abscisic acids are elevated, associated with massive upregulation of pathogenesis and abiotic stress-related genes and enhanced tolerance to fungal infection and drought. • We suggest that HCT downregulated alfalfa plants exhibit constitutive activation of defense responses, triggered by release of bioactive cell wall fragments and production of hydrogen peroxide as a result of impaired secondary cell wall integrity. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  10. Data from: Effects of multi-generational stress exposure and offspring environment on the expression and persistence of transgenerational effects in Arabidopsis thaliana

    NARCIS (Netherlands)

    Groot, M.; Kooke, R.; Knoben, Nieke; Vergeer, P.; Keurentjes, J.J.B.; Ouborg, N.J.; Verhoeven, Koen J.F.

    2016-01-01

    Phenotype data of A. thaliana plants grown in either a field environment or in a climate chamber environment. In the climate chamber environment plants were grown under control conditions or salt stress.

  11. Herbivore-induced volatile production by Arabidopsis thaliana leads to attraction of the parasitoid Cotesia rubecula: chemical, behavioral, and gene-expression analysis

    NARCIS (Netherlands)

    Poecke, R.M.P.; Posthumus, M.A.; Dicke, M.

    2001-01-01

    Many plant species defend themselves against herbivorous insects indirectly by producing volatiles in response to herbivory. These volatiles attract carnivorous enemies of the herbivores. Research on the model plant Arabidopsis thaliana (L.) Heynh. has contributed considerably to the unraveling of

  12. Constitutive expression of a fungus-inducible carboxylesterase improves disease resistance in transgenic pepper plants.

    Science.gov (United States)

    Ko, Moonkyung; Cho, Jung Hyun; Seo, Hyo-Hyoun; Lee, Hyun-Hwa; Kang, Ha-Young; Nguyen, Thai Son; Soh, Hyun Cheol; Kim, Young Soon; Kim, Jeong-Il

    2016-08-01

    Resistance against anthracnose fungi was enhanced in transgenic pepper plants that accumulated high levels of a carboxylesterase, PepEST in anthracnose-susceptible fruits, with a concurrent induction of antioxidant enzymes and SA-dependent PR proteins. A pepper esterase gene (PepEST) is highly expressed during the incompatible interaction between ripe fruits of pepper (Capsicum annuum L.) and a hemibiotrophic anthracnose fungus (Colletotrichum gloeosporioides). In this study, we found that exogenous application of recombinant PepEST protein on the surface of the unripe pepper fruits led to a potentiated state for disease resistance in the fruits, including generation of hydrogen peroxide and expression of pathogenesis-related (PR) genes that encode mostly small proteins with antimicrobial activity. To elucidate the role of PepEST in plant defense, we further developed transgenic pepper plants overexpressing PepEST under the control of CaMV 35S promoter. Molecular analysis confirmed the establishment of three independent transgenic lines carrying single copy of transgenes. The level of PepEST protein was estimated to be approximately 0.002 % of total soluble protein in transgenic fruits. In response to the anthracnose fungus, the transgenic fruits displayed higher expression of PR genes, PR3, PR5, PR10, and PepThi, than non-transgenic control fruits did. Moreover, immunolocalization results showed concurrent localization of ascorbate peroxidase (APX) and PR3 proteins, along with the PepEST protein, in the infected region of transgenic fruits. Disease rate analysis revealed significantly low occurrence of anthracnose disease in the transgenic fruits, approximately 30 % of that in non-transgenic fruits. Furthermore, the transgenic plants also exhibited resistance against C. acutatum and C. coccodes. Collectively, our results suggest that overexpression of PepEST in pepper confers enhanced resistance against the anthracnose fungi by activating the defense signaling

  13. Evaluation of constitutive iron reductase (AtFRO2 expression on mineral accumulation and distribution in soybean (Glycine max. L

    Directory of Open Access Journals (Sweden)

    Marta Wilton Vasconcelos

    2014-04-01

    Full Text Available Iron is an important micronutrient in human and plant nutrition. Adequate iron nutrition during crop production is central for assuring appropriate iron concentrations in the harvestable organs, for human food or animal feed. The whole-plant movement of iron involves several processes, including the reduction of ferric to ferrous iron at several locations throughout the plant, prior to transmembrane trafficking of ferrous iron. In this study, soybean plants that constitutively expressed the AtFRO2 iron reductase gene were analyzed for leaf iron reductase activity, as well as the effect of this transgene's expression on root, leaf, pod wall, and seed mineral concentrations. High Fe supply, in combination with the constitutive expression of AtFRO2, resulted in significantly higher concentrations of different minerals in roots (K, P, Zn, Ca, Ni, Mg and Mo, pod walls (Fe, K, P, Cu and Ni, leaves (Fe, P, Cu, Ca, Ni and Mg and seeds (Fe, Zn, Cu and Ni. Leaf and pod wall iron concentrations increased as much as 500% in transgenic plants, while seed iron concentrations only increased by 10%, suggesting that factors other than leaf and pod wall reductase activity were limiting the translocation of iron to seeds. Protoplasts isolated from transgenic leaves had three-fold higher reductase activity than controls. Expression levels of the iron storage protein, ferritin, were higher in the transgenic leaves than in wild-type, suggesting that the excess iron may be stored as ferritin in the leaves and therefore unavailable for phloem loading and delivery to the seeds. Also, citrate and malate levels in the roots and leaves of transgenic plants were significantly higher than in wild-type, suggesting that organic acid production could be related to the increased accumulation of minerals in roots, leaves and pod walls, but not in the seeds. All together, these results suggest a more ubiquitous role for the iron reductase in whole-plant mineral accumulation and

  14. Biallelic MLH1 SNP cDNA expression or constitutional promoter methylation can hide genomic rearrangements causing Lynch syndrome.

    Science.gov (United States)

    Morak, Monika; Koehler, Udo; Schackert, Hans Konrad; Steinke, Verena; Royer-Pokora, Brigitte; Schulmann, Karsten; Kloor, Matthias; Höchter, Wilhelm; Weingart, Josef; Keiling, Cortina; Massdorf, Trisari; Holinski-Feder, Elke

    2011-08-01

    A positive family history, germline mutations in DNA mismatch repair genes, tumours with high microsatellite instability, and loss of mismatch repair protein expression are the hallmarks of hereditary non-polyposis colorectal cancer (Lynch syndrome). However, in ~10-15% of cases of suspected Lynch syndrome, no disease-causing mechanism can be detected. Oligo array analysis was performed to search for genomic imbalances in patients with suspected mutation-negative Lynch syndrome with MLH1 deficiency in their colorectal tumours. A deletion in the LRRFIP2 (leucine-rich repeat flightless-interacting protein 2) gene flanking the MLH1 gene was detected, which turned out to be a paracentric inversion on chromosome 3p22.2 creating two new stable fusion transcripts between MLH1 and LRRFIP2. A single-nucleotide polymorphism in MLH1 exon 8 was expressed from both alleles, initially pointing to appropriate MLH1 function at least in peripheral cells. In a second case, an inherited duplication of the MLH1 gene region resulted in constitutional MLH1 promoter methylation. Constitutional MLH1 promoter methylation may therefore in rare cases be a heritable disease mechanism and should not be overlooked in seemingly sporadic patients.

  15. Cytosolic Calcium, hydrogen peroxide, and related gene expression and protein modulation in Arabidopsis thaliana cell cultures respond immediately to altered gravitation: Parabolic flight data

    Science.gov (United States)

    Hampp, Ruediger; Hausmann, Niklas; Neef, Maren; Fengler, Svenja

    Callus cell cultures of Arabidopsis thaliana (cv. Columbia) were exposed to parabolic flights in order to assess molecular short-term responses to altered gravity fields. Using transgenic cell lines, hydrogen peroxide and cytosolic Ca2+ were continuously monitored. In parallel, the metabolism of samples was chemically quenched (RNAlater, Ambion, for RNA; acid/base for NADPH, NADP) at typical stages of a parabola (1g before pull up; end of pull up (1.8 g), end of microgravity (µg, 20 sec), and end of pull out (1.8 g)). Cells exhibited an increase of both Ca2+ and hydrogen peroxide with the onset of µg, and a decline thereafter. This behaviour was accompanied by a decrease of the NADPH/NADP redox ratio, indicating a Ca2+-dependent activation of a NADPH oxidase. Microarray analyses revealed concomitant expression profiles. At the end of the microgravity phase, 396 transcripts were specifically up-, while 485 were down-regulated. Up-regulation was dominated by Ca2+- and ROS(reactive oxygen species)-related gene products. The same material was also used for the analysis of phosphopeptides by 2D SDS PAGE. Relevant spots were identified by liquid chromatography-MS. With the exception of a chaperone (HSP 70-3), hypergravity (1.8 g) and microgravity modified different sets of proteins. These are partly involved in primary metabolism (glycolysis, gluconeogenesis, citrate cycle) and detoxification of reactive oxygen species. Taken together, these data show that both gene expression and protein modulation jointly respond within seconds to alterations in the gravity field, with a focus on metabolic adaptation, signalling and control of ROS.

  16. Production of dengue virus envelope protein domain III-based antigens in tobacco chloroplasts using inducible and constitutive expression systems.

    Science.gov (United States)

    Gottschamel, Johanna; Lössl, Andreas; Ruf, Stephanie; Wang, Yanliang; Skaugen, Morten; Bock, Ralph; Clarke, Jihong Liu

    2016-07-01

    Dengue fever is a disease in many parts of the tropics and subtropics and about half the world's population is at risk of infection according to the World Health Organization. Dengue is caused by any of the four related dengue virus serotypes DEN-1, -2, -3 and -4, which are transmitted to people by Aedes aegypti mosquitoes. Currently there is only one vaccine (Dengvaxia(®)) available (limited to a few countries) on the market since 2015 after half a century's intensive efforts. Affordable and accessible vaccines against dengue are hence still urgently needed. The dengue envelop protein domain III (EDIII), which is capable of eliciting serotype-specific neutralizing antibodies, has become the focus for subunit vaccine development. To contribute to the development of an accessible and affordable dengue vaccine, in the current study we have used plant-based vaccine production systems to generate a dengue subunit vaccine candidate in tobacco. Chloroplast genome engineering was applied to express serotype-specific recombinant EDIII proteins in tobacco chloroplasts using both constitutive and ethanol-inducible expression systems. Expression of a tetravalent antigen fusion construct combining EDIII polypeptides from all four serotypes was also attempted. Transplastomic EDIII-expressing tobacco lines were obtained and homoplasmy was verified by Southern blot analysis. Northern blot analyses showed expression of EDIII antigen-encoding genes. EDIII protein accumulation levels varied for the different recombinant EDIII proteins and the different expression systems, and reached between 0.8 and 1.6 % of total cellular protein. Our study demonstrates the suitability of the chloroplast compartment as a production site for an EDIII-based vaccine candidate against dengue fever and presents a Gateway(®) plastid transformation vector for inducible transgene expression.

  17. PRDM14 is expressed in germ cell tumors with constitutive overexpression altering human germline differentiation and proliferation

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    Joanna J. Gell

    2018-03-01

    Full Text Available Germ cell tumors (GCTs are a heterogeneous group of tumors occurring in gonadal and extragonadal locations. GCTs are hypothesized to arise from primordial germ cells (PGCs, which fail to differentiate. One recently identified susceptibility loci for human GCT is PR (PRDI-BF1 and RIZ domain proteins 14 (PRDM14. PRDM14 is expressed in early primate PGCs and is repressed as PGCs differentiate. To examine PRDM14 in human GCTs we profiled human GCT cell lines and patient samples and discovered that PRDM14 is expressed in embryonal carcinoma cell lines, embryonal carcinomas, seminomas, intracranial germinomas and yolk sac tumors, but is not expressed in teratomas. To model constitutive overexpression in human PGCs, we generated PGC-like cells (PGCLCs from human pluripotent stem cells (PSCs and discovered that elevated expression of PRDM14 does not block early PGC formation. Instead, we show that elevated PRDM14 in PGCLCs causes proliferation and differentiation defects in the germline. Keywords: Germ cell tumor, PRDM14, Cell differentiation, Primordial germ cell, Proliferation

  18. Constitutive gene expression profile segregates toxicity in locally advanced breast cancer patients treated with high-dose hyperfractionated radical radiotherapy

    International Nuclear Information System (INIS)

    Henríquez Hernández, Luis Alberto; Lara, Pedro Carlos; Pinar, Beatriz; Bordón, Elisa; Gallego, Carlos Rodríguez; Bilbao, Cristina; Pérez, Leandro Fernández; Morales, Amílcar Flores

    2009-01-01

    Breast cancer patients show a wide variation in normal tissue reactions after radiotherapy. The individual sensitivity to x-rays limits the efficiency of the therapy. Prediction of individual sensitivity to radiotherapy could help to select the radiation protocol and to improve treatment results. The aim of this study was to assess the relationship between gene expression profiles of ex vivo un-irradiated and irradiated lymphocytes and the development of toxicity due to high-dose hyperfractionated radiotherapy in patients with locally advanced breast cancer. Raw data from microarray experiments were uploaded to the Gene Expression Omnibus Database http://www.ncbi.nlm.nih.gov/geo/ (GEO accession GSE15341). We obtained a small group of 81 genes significantly regulated by radiotherapy, lumped in 50 relevant pathways. Using ANOVA and t-test statistical tools we found 20 and 26 constitutive genes (0 Gy) that segregate patients with and without acute and late toxicity, respectively. Non-supervised hierarchical clustering was used for the visualization of results. Six and 9 pathways were significantly regulated respectively. Concerning to irradiated lymphocytes (2 Gy), we founded 29 genes that separate patients with acute toxicity and without it. Those genes were gathered in 4 significant pathways. We could not identify a set of genes that segregates patients with and without late toxicity. In conclusion, we have found an association between the constitutive gene expression profile of peripheral blood lymphocytes and the development of acute and late toxicity in consecutive, unselected patients. These observations suggest the possibility of predicting normal tissue response to irradiation in high-dose non-conventional radiation therapy regimens. Prospective studies with higher number of patients are needed to validate these preliminary results

  19. Expression pattern of the AHP gene family from Arabidopsis thaliana and organ specific alternative splicing in the AHP5 gene

    Czech Academy of Sciences Publication Activity Database

    Hradilová, Jana; Brzobohatý, Břetislav

    2007-01-01

    Roč. 51, č. 2 (2007), s. 257-267 ISSN 0006-3134 Grant - others:GA MŠk(CZ) LN00A081; GA AV ČR(CZ) IAA600040612 Program:LN; IA Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Arabidopsis two component systems * gene expression analysis * real time RT-PCR Subject RIV: BO - Biophysics Impact factor: 1.259, year: 2007

  20. Gibberellic acid alleviates cadmium toxicity by reducing nitric oxide accumulation and expression of IRT1 in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Zhu, Xiao Fang; Jiang, Tao; Wang, Zhi Wei; Lei, Gui Jie; Shi, Yuan Zhi; Li, Gui Xin; Zheng, Shao Jian

    2012-01-01

    Highlights: ► Cd reduces endogenous GA levels in Arabidopsis. ► GA exogenous applied decreases Cd accumulation in plant. ► GA suppresses the Cd-induced accumulation of NO. ► Decreased NO level downregulates the expression of IRT1. ► Suppressed IRT1 expression reduces Cd transport across plasma membrane. - Abstract: Gibberellic acid (GA) is involved in not only plant growth and development but also plant responses to abiotic stresses. Here it was found that treating the plants with GA concentrations from 0.1 to 5 μM for 24 h had no obvious effect on root elongation in the absence of cadmium (Cd), whereas in the presence of Cd 2+ , GA at 5 μM improved root growth, reduced Cd content and lipid peroxidation in the roots, indicating that GA can partially alleviate Cd toxicity. Cd 2+ increased nitric oxide (NO) accumulation in the roots, but GA remarkably reduced it, and suppressed the up-regulation of the expression of IRT1. In contrary, the beneficial effect of GA on alleviating Cd toxicity was not observed in an IRT1 knock-out mutant irt1, suggesting the involvement of IRT1 in Cd 2+ absorption. Furthermore, the GA-induced reduction of NO and Cd content can also be partially reversed by the application of a NO donor (S-nitrosoglutathione [GSNO]). Taken all these together, the results showed that GA-alleviated Cd toxicity is mediated through the reduction of the Cd-dependent NO accumulation and expression of Cd 2+ uptake related gene-IRT1 in Arabidopsis.

  1. Gibberellic acid alleviates cadmium toxicity by reducing nitric oxide accumulation and expression of IRT1 in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiao Fang [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Jiang, Tao [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Wang, Zhi Wei [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Lei, Gui Jie [Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Shi, Yuan Zhi [The Key Laboratory of Tea Chemical Engineering, Ministry of Agriculture, Yunqi Road 1, Hangzhou 310008 (China); Li, Gui Xin, E-mail: guixinli@zju.edu.cn [College of Agronomy and Biotechnology, Zhejiang University, Hangzhou 310058 (China); Zheng, Shao Jian [State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Cd reduces endogenous GA levels in Arabidopsis. Black-Right-Pointing-Pointer GA exogenous applied decreases Cd accumulation in plant. Black-Right-Pointing-Pointer GA suppresses the Cd-induced accumulation of NO. Black-Right-Pointing-Pointer Decreased NO level downregulates the expression of IRT1. Black-Right-Pointing-Pointer Suppressed IRT1 expression reduces Cd transport across plasma membrane. - Abstract: Gibberellic acid (GA) is involved in not only plant growth and development but also plant responses to abiotic stresses. Here it was found that treating the plants with GA concentrations from 0.1 to 5 {mu}M for 24 h had no obvious effect on root elongation in the absence of cadmium (Cd), whereas in the presence of Cd{sup 2+}, GA at 5 {mu}M improved root growth, reduced Cd content and lipid peroxidation in the roots, indicating that GA can partially alleviate Cd toxicity. Cd{sup 2+} increased nitric oxide (NO) accumulation in the roots, but GA remarkably reduced it, and suppressed the up-regulation of the expression of IRT1. In contrary, the beneficial effect of GA on alleviating Cd toxicity was not observed in an IRT1 knock-out mutant irt1, suggesting the involvement of IRT1 in Cd{sup 2+} absorption. Furthermore, the GA-induced reduction of NO and Cd content can also be partially reversed by the application of a NO donor (S-nitrosoglutathione [GSNO]). Taken all these together, the results showed that GA-alleviated Cd toxicity is mediated through the reduction of the Cd-dependent NO accumulation and expression of Cd{sup 2+} uptake related gene-IRT1 in Arabidopsis.

  2. Differential requirements of two recA mutants for constitutive SOS expression in Escherichia coli K-12.

    Directory of Open Access Journals (Sweden)

    Jarukit Edward Long

    Full Text Available Repairing DNA damage begins with its detection and is often followed by elicitation of a cellular response. In E. coli, RecA polymerizes on ssDNA produced after DNA damage and induces the SOS Response. The RecA-DNA filament is an allosteric effector of LexA auto-proteolysis. LexA is the repressor of the SOS Response. Not all RecA-DNA filaments, however, lead to an SOS Response. Certain recA mutants express the SOS Response (recA(C in the absence of external DNA damage in log phase cells.Genetic analysis of two recA(C mutants was used to determine the mechanism of constitutive SOS (SOS(C expression in a population of log phase cells using fluorescence of single cells carrying an SOS reporter system (sulAp-gfp. SOS(C expression in recA4142 mutants was dependent on its initial level of transcription, recBCD, recFOR, recX, dinI, xthA and the type of medium in which the cells were grown. SOS(C expression in recA730 mutants was affected by none of the mutations or conditions tested above.It is concluded that not all recA(C alleles cause SOS(C expression by the same mechanism. It is hypothesized that RecA4142 is loaded on to a double-strand end of DNA and that the RecA filament is stabilized by the presence of DinI and destabilized by RecX. RecFOR regulate the activity of RecX to destabilize the RecA filament. RecA730 causes SOS(C expression by binding to ssDNA in a mechanism yet to be determined.

  3. A three-component gene expression system and its application for inducible flavonoid overproduction in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Feng, Yue; Cao, Cong-Mei; Vikram, Meenu; Park, Sunghun; Kim, Hye Jin; Hong, Jong Chan; Cisneros-Zevallos, Luis; Koiwa, Hisashi

    2011-03-08

    Inducible gene expression is a powerful tool to study and engineer genes whose overexpression could be detrimental for the host organisms. However, only limited systems have been adopted in plant biotechnology. We have developed an osmotically inducible system using three components of plant origin, RD29a (Responsive to Dehydration 29A) promoter, CBF3 (C-repeat Binding Factor 3) transcription factor and cpl1-2 (CTD phosphatase-like 1) mutation. The osmotic stress responsible RD29a promoter contains the CBF3 binding sites and thus RD29A-CBF3 feedforward cassette enhances induction of RD29a promoter under stress. The cpl1-2 mutation in a host repressor CPL1 promotes stress responsible RD29a promoter expression. The efficacy of this system was tested using PAP1 (Production of Anthocyanin Pigment 1) transgene, a model transcription factor that regulates the anthocyanin pathway in Arabidopsis. While transgenic plants with only one or two of three components did not reproducibly accumulate anthocyanin pigments above the control level, transgenic cpl1 plants containing homozygous RD29a-PAP1 and RD29a-CBF3 transgenes produced 30-fold higher level of total anthocyanins than control plants upon cold treatment. Growth retardation and phytochemical production of transgenic plants were minimum under normal conditions. The flavonoid profile in cold-induced transgenic plants was determined by LC/MS/MS, which resembled that of previously reported pap1-D plants but enriched for kaempferol derivatives. These results establish the functionality of the inducible three-component gene expression system in plant metabolic engineering. Furthermore, we show that PAP1 and environmental signals synergistically regulate the flavonoid pathway to produce a unique flavonoid blend that has not been produced by PAP1 overexpression or cold treatment alone.

  4. A three-component gene expression system and its application for inducible flavonoid overproduction in transgenic Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Yue Feng

    Full Text Available Inducible gene expression is a powerful tool to study and engineer genes whose overexpression could be detrimental for the host organisms. However, only limited systems have been adopted in plant biotechnology. We have developed an osmotically inducible system using three components of plant origin, RD29a (Responsive to Dehydration 29A promoter, CBF3 (C-repeat Binding Factor 3 transcription factor and cpl1-2 (CTD phosphatase-like 1 mutation. The osmotic stress responsible RD29a promoter contains the CBF3 binding sites and thus RD29A-CBF3 feedforward cassette enhances induction of RD29a promoter under stress. The cpl1-2 mutation in a host repressor CPL1 promotes stress responsible RD29a promoter expression. The efficacy of this system was tested using PAP1 (Production of Anthocyanin Pigment 1 transgene, a model transcription factor that regulates the anthocyanin pathway in Arabidopsis. While transgenic plants with only one or two of three components did not reproducibly accumulate anthocyanin pigments above the control level, transgenic cpl1 plants containing homozygous RD29a-PAP1 and RD29a-CBF3 transgenes produced 30-fold higher level of total anthocyanins than control plants upon cold treatment. Growth retardation and phytochemical production of transgenic plants were minimum under normal conditions. The flavonoid profile in cold-induced transgenic plants was determined by LC/MS/MS, which resembled that of previously reported pap1-D plants but enriched for kaempferol derivatives. These results establish the functionality of the inducible three-component gene expression system in plant metabolic engineering. Furthermore, we show that PAP1 and environmental signals synergistically regulate the flavonoid pathway to produce a unique flavonoid blend that has not been produced by PAP1 overexpression or cold treatment alone.

  5. Impact of AtNHX1, a vacuolar Na+/H+ antiporter, upon gene expression during short- and long-term salt stress in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Blumwald Eduardo

    2007-04-01

    Full Text Available Abstract Background AtNHX1, the most abundant vacuolar Na+/H+ antiporter in Arabidopsis thaliana, mediates the transport of Na+ and K+ into the vacuole, influencing plant development and contributing to salt tolerance. In this report, microarray expression profiles of wild type plants, a T-DNA insertion knockout mutant of AtNHX1 (nhx1, and a 'rescued' line (NHX1::nhx1 were exposed to both short (12 h and 48 h and long (one and two weeks durations of a non-lethal salt stress to identify key gene transcripts associated with the salt response that are influenced by AtNHX1. Results 147 transcripts showed both salt responsiveness and a significant influence of AtNHX1. Fifty-seven of these genes showed an influence of the antiporter across all salt treatments, while the remaining genes were influenced as a result of a particular duration of salt stress. Most (69% of the genes were up-regulated in the absence of AtNHX1, with the exception of transcripts encoding proteins involved with metabolic and energy processes that were mostly down-regulated. Conclusion While part of the AtNHX1-influenced transcripts were unclassified, other transcripts with known or putative roles showed the importance of AtNHX1 to key cellular processes that were not necessarily limited to the salt stress response; namely calcium signaling, sulfur metabolism, cell structure and cell growth, as well as vesicular trafficking and protein processing. Only a small number of other salt-responsive membrane transporter transcripts appeared significantly influenced by AtNHX1.

  6. Arabidopsis thaliana Contains Both Ni2+ and Zn2+ Dependent Glyoxalase I Enzymes and Ectopic Expression of the Latter Contributes More towards Abiotic Stress Tolerance in E. coli.

    Directory of Open Access Journals (Sweden)

    Muskan Jain

    Full Text Available The glyoxalase pathway is ubiquitously found in all the organisms ranging from prokaryotes to eukaryotes. It acts as a major pathway for detoxification of methylglyoxal (MG, which deleteriously affects the biological system in stress conditions. The first important enzyme of this system is Glyoxalase I (GLYI. It is a metalloenzyme which requires divalent metal ions for its activity. This divalent metal ion can be either Zn2+ as found in most of eukaryotes or Ni2+ as seen in prokaryotes. In the present study, we have found three active GLYI enzymes (AtGLYI2, AtGLYI3 and AtGLYI6 belonging to different metal activation classes coexisting in Arabidopsis thaliana. These enzymes have been found to efficiently complement the GLYI yeast mutants. These three enzymes have been characterized in terms of their activity, metal dependency, kinetic parameters and their role in conferring tolerance to multiple abiotic stresses in E. coli and yeast. AtGLYI2 was found to be Zn2+ dependent whereas AtGLYI3 and AtGLYI6 were Ni2+ dependent. Enzyme activity of Zn2+ dependent enzyme, AtGLYI2, was observed to be exceptionally high (~250-670 fold as compared to Ni2+ dependent enzymes, AtGLYI3 and AtGLYI6. The activity of these GLYI enzymes correlated well to their role in stress tolerance. Heterologous expression of these enzymes in E. coli led to better tolerance against various stress conditions. This is the first report of a higher eukaryotic species having multiple active GLYI enzymes belonging to different metal activation classes.

  7. Constitutively expressed Protocadherin-α regulates the coalescence and elimination of homotypic olfactory axons through its cytoplasmic region

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    Sonoko eHasegawa

    2012-10-01

    Full Text Available Olfactory sensory neuron (OSN axons coalesce into specific glomeruli in the olfactory bulb (OB according to their odorant receptor (OR expression. Several guidance molecules enhance the coalescence of homotypic OSN projections, in an OR-specific- and neural-activity-dependent manner. However, the mechanism by which homotypic OSN axons are organized into glomeruli is unsolved. We previously reported that the clustered protocadherin-α (Pcdh-α family of diverse cadherin-related molecules plays roles in the coalescence and elimination of homotypic OSN axons throughout development. Here we showed that the elimination of small ectopic homotypic glomeruli required the constitutive expression of a Pcdh-α isoform and Pcdh-α’s cytoplasmic region, but not OR specificity or neural activity. These results suggest that Pcdh-α proteins provide a cytoplasmic signal to regulate repulsive activity for homotypic OSN axons independently of OR expression and neural activity. The counterbalancing effect of Pcdh-α proteins for the axonal coalescence mechanisms mediated by other olfactory guidance molecules indicate a possible mechanism for the organization of homotypic OSN axons into glomeruli during development.

  8. Improvement of enzymatic saccharification yield in Arabidopsis thaliana by ectopic expression of the rice SUB1A-1 transcription factor

    Directory of Open Access Journals (Sweden)

    Lizeth Núñez-López

    2015-03-01

    Full Text Available Saccharification of polysaccharides releases monosaccharides that can be used by ethanol-producing microorganisms in biofuel production. To improve plant biomass as a raw material for saccharification, factors controlling the accumulation and structure of carbohydrates must be identified. Rice SUB1A-1 is a transcription factor that represses the turnover of starch and postpones energy-consuming growth processes under submergence stress. Arabidopsis was employed to test if heterologous expression of SUB1A-1 or SUB1C-1 (a related gene can be used to improve saccharification. Cellulolytic and amylolytic enzymatic treatments confirmed that SUB1A-1 transgenics had better saccharification yield than wild-type (Col-0, mainly from accumulated starch. This improved saccharification yield was developmentally controlled; when compared to Col-0, young transgenic vegetative plants yielded 200–300% more glucose, adult vegetative plants yielded 40–90% more glucose and plants in reproductive stage had no difference in yield. We measured photosynthetic parameters, starch granule microstructure, and transcript abundance of genes involved in starch degradation (SEX4, GWD1, juvenile transition (SPL3-5 and meristematic identity (FUL, SOC1 but found no differences to Col-0, indicating that starch accumulation may be controlled by down-regulation of CONSTANS and FLOWERING LOCUS T by SUB1A-1 as previously reported. SUB1A-1 transgenics also offered less resistance to deformation than wild-type concomitant to up-regulation of AtEXP2 expansin and BGL2 glucan-1,3,-beta-glucosidase. We conclude that heterologous SUB1A-1 expression can improve saccharification yield and softness, two traits needed in bioethanol production.

  9. Expression analysis of the Arabidopsis thaliana AtSpen2 gene, and its relationship with other plant genes encoding Spen proteins

    OpenAIRE

    Solís-Guzmán, María Gloria; Argüello-Astorga, Gerardo; López-Bucio, José; Ruiz-Herrera, León Francisco; López-Meza, Joel; Sánchez-Calderón, Lenin; Carreón-Abud, Yazmín; Martínez-Trujillo, Miguel

    2017-01-01

    Abstract Proteins of the Split ends (Spen) family are characterized by an N-terminal domain, with one or more RNA recognition motifs and a SPOC domain. In Arabidopsis thaliana, the Spen protein FPA is involved in the control of flowering time as a component of an autonomous pathway independent of photoperiod. The A. thaliana genome encodes another gene for a putative Spen protein at the locus At4g12640, herein named AtSpen2. Bioinformatics analysis of the AtSPEN2 SPOC domain revealed low sequ...

  10. Saccharomyces cerevisiae FKBP12 binds Arabidopsis thaliana TOR and its expression in plants leads to rapamycin susceptibility.

    Science.gov (United States)

    Sormani, Rodnay; Yao, Lei; Menand, Benoît; Ennar, Najla; Lecampion, Cécile; Meyer, Christian; Robaglia, Christophe

    2007-06-01

    The eukaryotic TOR pathway controls translation, growth and the cell cycle in response to environmental signals such as nutrients or growth-stimulating factors. The TOR protein kinase can be inactivated by the antibiotic rapamycin following the formation of a ternary complex between TOR, rapamycin and FKBP12 proteins. The TOR protein is also found in higher plants despite the fact that they are rapamycin insensitive. Previous findings using the yeast two hybrid system suggest that the FKBP12 plant homolog is unable to form a complex with rapamycin and TOR, while the FRB domain of plant TOR is still able to bind to heterologous FKBP12 in the presence of rapamycin. The resistance to rapamycin is therefore limiting the molecular dissection of the TOR pathway in higher plants. Here we show that none of the FKBPs from the model plant Arabidopsis (AtFKBPs) is able to form a ternary complex with the FRB domain of AtTOR in the presence of rapamycin in a two hybrid system. An antibody has been raised against the AtTOR protein and binding of recombinant yeast ScFKBP12 to native Arabidopsis TOR in the presence of rapamycin was demonstrated in pull-down experiments. Transgenic lines expressing ScFKBP12 were produced and were found to display a rapamycin-dependent reduction of the primary root growth and a lowered accumulation of high molecular weight polysomes. These results further strengthen the idea that plant resistance to rapamycin evolved as a consequence of mutations in plant FKBP proteins. The production of rapamycin-sensitive plants through the expression of the ScFKBP12 protein illustrates the conservation of the TOR pathway in eukaryotes. Since AtTOR null mutants were found to be embryo lethal 1, transgenic ScFKBP12 plants will provide an useful tool for the post-embryonic study of plant TOR functions. This work also establish for the first time a link between TOR activity and translation in plant cells.

  11. Saccharomyces cerevisiae FKBP12 binds Arabidopsis thaliana TOR and its expression in plants leads to rapamycin susceptibility

    Directory of Open Access Journals (Sweden)

    Meyer Christian

    2007-06-01

    Full Text Available Abstract Background The eukaryotic TOR pathway controls translation, growth and the cell cycle in response to environmental signals such as nutrients or growth-stimulating factors. The TOR protein kinase can be inactivated by the antibiotic rapamycin following the formation of a ternary complex between TOR, rapamycin and FKBP12 proteins. The TOR protein is also found in higher plants despite the fact that they are rapamycin insensitive. Previous findings using the yeast two hybrid system suggest that the FKBP12 plant homolog is unable to form a complex with rapamycin and TOR, while the FRB domain of plant TOR is still able to bind to heterologous FKBP12 in the presence of rapamycin. The resistance to rapamycin is therefore limiting the molecular dissection of the TOR pathway in higher plants. Results Here we show that none of the FKBPs from the model plant Arabidopsis (AtFKBPs is able to form a ternary complex with the FRB domain of AtTOR in the presence of rapamycin in a two hybrid system. An antibody has been raised against the AtTOR protein and binding of recombinant yeast ScFKBP12 to native Arabidopsis TOR in the presence of rapamycin was demonstrated in pull-down experiments. Transgenic lines expressing ScFKBP12 were produced and were found to display a rapamycin-dependent reduction of the primary root growth and a lowered accumulation of high molecular weight polysomes. Conclusion These results further strengthen the idea that plant resistance to rapamycin evolved as a consequence of mutations in plant FKBP proteins. The production of rapamycin-sensitive plants through the expression of the ScFKBP12 protein illustrates the conservation of the TOR pathway in eukaryotes. Since AtTOR null mutants were found to be embryo lethal 1, transgenic ScFKBP12 plants will provide an useful tool for the post-embryonic study of plant TOR functions. This work also establish for the first time a link between TOR activity and translation in plant cells

  12. Identification of centrarchid hepcidins and evidence that 17β-estradiol disrupts constitutive expression of hepcidin-1 and inducible expression of hepcidin-2 in largemouth bass (Micropterus salmoides)

    Science.gov (United States)

    Robertson, L.S.; Iwanowicz, L.R.; Marranca, J.M.

    2009-01-01

    Hepcidin is a highly conserved antimicrobial peptide and iron-regulatory hormone. Here, we identify two hepcidin genes (hep-1 and hep-2) in largemouth bass (Micropterus salmoides) and smallmouth bass (Micropterus dolomieu). Hepcidin-1 contains a putative ATCUN metal-binding site in the amino-terminus that is missing in hepcidin-2, suggesting that hepcidin-1 may function as an iron-regulatory hormone. Both hepcidins are predominately expressed in the liver of largemouth bass, similar to other fish and mammals. Experimental exposure of pond-raised largemouth bass to 17β-estradiol and/or the bacteria Edwardsiella ictaluri led to distinct changes in expression of hep-1 and hep-2. Estradiol reduced the constitutive expression of hep-1 in the liver. Bacterial exposure induced expression of hep-2, suggesting that hepcidin-2 may have an antimicrobial function, and this induction was abolished by estradiol. To our knowledge, this is the first report of the regulation of hepcidin expression by estradiol in either fish or mammals.

  13. Identification of centrarchid hepcidins and evidence that 17beta-estradiol disrupts constitutive expression of hepcidin-1 and inducible expression of hepcidin-2 in largemouth bass (Micropterus salmoides).

    Science.gov (United States)

    Robertson, Laura S; Iwanowicz, Luke R; Marranca, Jamie Marie

    2009-06-01

    Hepcidin is a highly conserved antimicrobial peptide and iron-regulatory hormone. Here, we identify two hepcidin genes (hep-1 and hep-2) in largemouth bass (Micropterus salmoides) and smallmouth bass (Micropterus dolomieu). Hepcidin-1 contains a putative ATCUN metal-binding site in the amino-terminus that is missing in hepcidin-2, suggesting that hepcidin-1 may function as an iron-regulatory hormone. Both hepcidins are predominately expressed in the liver of largemouth bass, similar to other fish and mammals. Experimental exposure of pond-raised largemouth bass to 17beta-estradiol and/or the bacteria Edwardsiella ictaluri led to distinct changes in expression of hep-1 and hep-2. Estradiol reduced the constitutive expression of hep-1 in the liver. Bacterial exposure induced expression of hep-2, suggesting that hepcidin-2 may have an antimicrobial function, and this induction was abolished by estradiol. To our knowledge, this is the first report of the regulation of hepcidin expression by estradiol in either fish or mammals.

  14. Expression of a constitutively activated plasma membrane H+-ATPase in Nicotiana tabacum BY-2 cells results in cell expansion.

    Science.gov (United States)

    Niczyj, Marta; Champagne, Antoine; Alam, Iftekhar; Nader, Joseph; Boutry, Marc

    2016-11-01

    Increased acidification of the external medium by an activated H + -ATPase results in cell expansion, in the absence of upstream activating signaling. The plasma membrane H + -ATPase couples ATP hydrolysis with proton transport outside the cell, and thus creates an electrochemical gradient, which energizes secondary transporters. According to the acid growth theory, this enzyme is also proposed to play a major role in cell expansion, by acidifying the external medium and so activating enzymes that are involved in cell wall-loosening. However, this theory is still debated. To challenge it, we made use of a plasma membrane H + -ATPase isoform from Nicotiana plumbaginifolia truncated from its C-terminal auto-inhibitory domain (ΔCPMA4), and thus constitutively activated. This protein was expressed in Nicotiana tabacum BY-2 suspension cells using a heat shock inducible promoter. The characterization of several independent transgenic lines showed that the expression of activated ΔCPMA4 resulted in a reduced external pH by 0.3-1.2 units, as well as in an increased H + -ATPase activity by 77-155 % (ATP hydrolysis), or 70-306 % (proton pumping) of isolated plasma membranes. In addition, ΔCPMA4-expressing cells were 17-57 % larger than the wild-type cells and displayed abnormal shapes. A proteomic comparison of plasma membranes isolated from ΔCPMA4-expressing and wild-type cells revealed the altered abundance of several proteins involved in cell wall synthesis, transport, and signal transduction. In conclusion, the data obtained in this work showed that H + -ATPase activation is sufficient to induce cell expansion and identified possible actors which intervene in this process.

  15. Nuclear and cellular expression data from the whole 16-cell stage Arabidopsis thaliana embryo and a cell type-specific expression atlas of the early Arabidopsis embryo

    NARCIS (Netherlands)

    Palovaara, J.P.J.

    2017-01-01

    SuperSeries contain expression data from the nuclei of cell types involved in patterning events, with focus on root apical stem cell formation, at 16-cell stage, early globular stage and late globular stage in the early Arabidopsis embryo (atlas). Expression data comparing nuclear and cellular RNA

  16. Yeast Fex1p Is a Constitutively Expressed Fluoride Channel with Functional Asymmetry of Its Two Homologous Domains*

    Science.gov (United States)

    Smith, Kathryn D.; Gordon, Patricia B.; Rivetta, Alberto; Allen, Kenneth E.; Berbasova, Tetyana; Slayman, Clifford; Strobel, Scott A.

    2015-01-01

    Fluoride is a ubiquitous environmental toxin with which all biological species must cope. A recently discovered family of fluoride export (FEX) proteins protects organisms from fluoride toxicity by removing it from the cell. We show here that FEX proteins in Saccharomyces cerevisiae function as ion channels that are selective for fluoride over chloride and that these proteins are constitutively expressed at the yeast plasma membrane. Continuous expression is in contrast to many other toxin exporters in yeast, and this, along with the fact that two nearly duplicate proteins are encoded in the yeast genome, suggests that the threat posed by fluoride ions is frequent and detrimental. Structurally, eukaryotic FEX proteins consist of two homologous four-transmembrane helix domains folded into an antiparallel dimer, where the orientation of the two domains is fixed by a single transmembrane linker helix. Using phylogenetic sequence conservation as a guide, we have identified several functionally important residues. There is substantial functional asymmetry in the effect of mutation at corresponding sites in the two domains. Specifically, mutations to residues in the C-terminal domain proved significantly more detrimental to function than did similar mutations in the N-terminal domain. Our data suggest particular residues that may be important to anion specificity, most notably the necessity of a positive charge near the end of TMH1 in the C-terminal domain. It is possible that a cationic charge at this location may create an electrostatic well for fluoride ions entering the channel from the cytoplasm. PMID:26055717

  17. A constitutively expressed antifungal peptide protects Tenebrio molitor during a natural infection by the entomopathogenic fungus Beauveria bassiana

    DEFF Research Database (Denmark)

    Maistrou, Sevasti; Paris, Véronique; Jensen, Annette Bruun

    2018-01-01

    -evolution they share. In this study, we investigated role of a constitutively expressed thaumatin-like peptide with antifungal activity expressed by the mealworm beetle Tenebrio molitor, named Tenecin 3, during a natural infection with the entomopathogenic fungus Beauveria bassiana. We monitored the effect...

  18. Expression differences for genes involved in lignin, glutathione and sulphate metabolism in response to cadmium in Arabidopsis thaliana and the related Zn/Cd-hyperaccumulator Thlaspi caerulescens

    NARCIS (Netherlands)

    van de Mortel, Judith E.; Schat, Henk; Moerland, Perry D.; Ver Loren van Themaat, Emiel; van der Ent, Sjoerd; Blankestijn, Hetty; Ghandilyan, Artak; Tsiatsiani, Styliani; Aarts, Mark G. M.

    2008-01-01

    Cadmium (Cd) is a widespread, naturally occurring element present in soil, rock, water, plants and animals. Cd is a non-essential element for plants and is toxic at higher concentrations. Transcript profiles of roots of Arabidopsis thaliana (Arabidopsis) and Thlaspi caerulescens plants exposed to Cd

  19. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of AHP2, a signal transmitter protein from Arabidopsis thaliana

    Czech Academy of Sciences Publication Activity Database

    Degtjarik, O.; Dopitová, R.; Puehringer, S.; Nejedlá, E.; Kutý, Michal; Weiss, M.S.; Hejatko, J.; Janda, L.; Kutá-Smatanová, Ivana

    2013-01-01

    Roč. 69, FEB 2013 (2013), s. 158-161 ISSN 1744-3091 Institutional support: RVO:67179843 Keywords : AHP2 * Arabidopsis thaliana * histidine phosphotransfer proteins * multi-step phosphorelay Subject RIV: CE - Biochemistry Impact factor: 0.568, year: 2013

  20. The rules of gene expression in plants: Organ identity and gene body methylation are key factors for regulation of gene expression in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Gutiérrez Rodrigo A

    2008-09-01

    Full Text Available Abstract Background Microarray technology is a widely used approach for monitoring genome-wide gene expression. For Arabidopsis, there are over 1,800 microarray hybridizations representing many different experimental conditions on Affymetrix™ ATH1 gene chips alone. This huge amount of data offers a unique opportunity to infer the principles that govern the regulation of gene expression in plants. Results We used bioinformatics methods to analyze publicly available data obtained using the ATH1 chip from Affymetrix. A total of 1887 ATH1 hybridizations were normalized and filtered to eliminate low-quality hybridizations. We classified and compared control and treatment hybridizations and determined differential gene expression. The largest differences in gene expression were observed when comparing samples obtained from different organs. On average, ten-fold more genes were differentially expressed between organs as compared to any other experimental variable. We defined "gene responsiveness" as the number of comparisons in which a gene changed its expression significantly. We defined genes with the highest and lowest responsiveness levels as hypervariable and housekeeping genes, respectively. Remarkably, housekeeping genes were best distinguished from hypervariable genes by differences in methylation status in their transcribed regions. Moreover, methylation in the transcribed region was inversely correlated (R2 = 0.8 with gene responsiveness on a genome-wide scale. We provide an example of this negative relationship using genes encoding TCA cycle enzymes, by contrasting their regulatory responsiveness to nitrate and methylation status in their transcribed regions. Conclusion Our results indicate that the Arabidopsis transcriptome is largely established during development and is comparatively stable when faced with external perturbations. We suggest a novel functional role for DNA methylation in the transcribed region as a key determinant

  1. Cell-type specific expression of constitutively-active Rheb promotes regeneration of bulbospinal respiratory axons following cervical SCI.

    Science.gov (United States)

    Urban, Mark W; Ghosh, Biswarup; Strojny, Laura R; Block, Cole G; Blazejewski, Sara M; Wright, Megan C; Smith, George M; Lepore, Angelo C

    2018-05-01

    Damage to respiratory neural circuitry and consequent loss of diaphragm function is a major cause of morbidity and mortality in individuals suffering from traumatic cervical spinal cord injury (SCI). Repair of CNS axons after SCI remains a therapeutic challenge, despite current efforts. SCI disrupts inspiratory signals originating in the rostral ventral respiratory group (rVRG) of the medulla from their phrenic motor neuron (PhMN) targets, resulting in loss of diaphragm function. Using a rat model of cervical hemisection SCI, we aimed to restore rVRG-PhMN-diaphragm circuitry by stimulating regeneration of injured rVRG axons via targeted induction of Rheb (ras homolog enriched in brain), a signaling molecule that regulates neuronal-intrinsic axon growth potential. Following C2 hemisection, we performed intra-rVRG injection of an adeno-associated virus serotype-2 (AAV2) vector that drives expression of a constitutively-active form of Rheb (cRheb). rVRG neuron-specific cRheb expression robustly increased mTOR pathway activity within the transduced rVRG neuron population ipsilateral to the hemisection, as assessed by levels of phosphorylated ribosomal S6 kinase. By co-injecting our novel AAV2-mCherry/WGA anterograde/trans-synaptic axonal tracer into rVRG, we found that cRheb expression promoted regeneration of injured rVRG axons into the lesion site, while we observed no rVRG axon regrowth with AAV2-GFP control. AAV2-cRheb also significantly reduced rVRG axonal dieback within the intact spinal cord rostral to the lesion. However, cRheb expression did not promote any recovery of ipsilateral hemi-diaphragm function, as assessed by inspiratory electromyography (EMG) burst amplitudes. This lack of functional recovery was likely because regrowing rVRG fibers did not extend back into the caudal spinal cord to synaptically reinnervate PhMNs that we retrogradely-labeled with cholera toxin B from the ipsilateral hemi-diaphragm. Our findings demonstrate that enhancing neuronal

  2. Ortho-aminoazotoluene activates mouse constitutive androstane receptor (mCAR) and increases expression of mCAR target genes

    International Nuclear Information System (INIS)

    Smetanina, Mariya A.; Pakharukova, Mariya Y.; Kurinna, Svitlana M.; Dong, Bingning; Hernandez, Juan P.; Moore, David D.; Merkulova, Tatyana I.

    2011-01-01

    2'-3-dimethyl-4-aminoazobenzene (ortho-aminoazotoluene, OAT) is an azo dye and a rodent carcinogen that has been evaluated by the International Agency for Research on Cancer (IARC) as a possible (class 2B) human carcinogen. Its mechanism of action remains unclear. We examined the role of the xenobiotic receptor Constitutive Androstane Receptor (CAR, NR1I3) as a mediator of the effects of OAT. We found that OAT increases mouse CAR (mCAR) transactivation in a dose-dependent manner. This effect is specific because another closely related azo dye, 3'-methyl-4-dimethyl-aminoazobenzene (3'MeDAB), did not activate mCAR. Real-time Q-PCR analysis in wild-type C57BL/6 mice revealed that OAT induces the hepatic mRNA expression of the following CAR target genes: Cyp2b10, Cyp2c29, Cyp3a11, Ugt1a1, Mrp4, Mrp2 and c-Myc. CAR-null (Car -/- ) mice showed no increased expression of these genes following OAT treatment, demonstrating that CAR is required for their OAT dependent induction. The OAT-induced CAR-dependent increase of Cyp2b10 and c-Myc expression was confirmed by Western blotting. Immunohistochemistry analysis of wild-type and Car -/- livers showed that OAT did not acutely induce hepatocyte proliferation, but at much later time points showed an unexpected CAR-dependent proliferative response. These studies demonstrate that mCAR is an OAT xenosensor, and indicate that at least some of the biological effects of this compound are mediated by this nuclear receptor. - Highlights: → The azo dye and mouse carcinogen OAT is a very effective mCAR activator. → OAT increases mCAR transactivation in a dose-dependent manner. → OAT CAR-dependently increases the expression of a specific subset of CAR target genes. → OAT induces an unexpectedly deferred, but CAR-dependent hepatocyte proliferation.

  3. Constitutive expression of fluorescent protein by Aspergillus var. niger and Aspergillus carbonarius to monitor fungal colonization in maize plants.

    Science.gov (United States)

    Palencia, Edwin Rene; Glenn, Anthony Elbie; Hinton, Dorothy Mae; Bacon, Charles Wilson

    2013-09-01

    Aspergillus niger and Aspergillus carbonarius are two species in the Aspergillus section Nigri (black-spored aspergilli) frequently associated with peanut (Arachis hypogea), maize (Zea mays), and other plants as pathogens. These infections are symptomless and as such are major concerns since some black aspergilli produce important mycotoxins, ochratoxins A, and the fumonisins. To facilitate the study of the black aspergilli-maize interactions with maize during the early stages of infections, we developed a method that used the enhanced yellow fluorescent protein (eYFP) and the monomeric red fluorescent protein (mRFP1) to transform A. niger and A. carbonarius, respectively. The results were constitutive expressions of the fluorescent genes that were stable in the cytoplasms of hyphae and conidia under natural environmental conditions. The hyphal in planta distribution in 21-day-old seedlings of maize were similar wild type and transformants of A. niger and A. carbonarius. The in planta studies indicated that both wild type and transformants internally colonized leaf, stem and root tissues of maize seedlings, without any visible disease symptoms. Yellow and red fluorescent strains were capable of invading epidermal cells of maize roots intercellularly within the first 3 days after inoculation, but intracellular hyphal growth was more evident after 7 days of inoculation. We also tested the capacity of fluorescent transformants to produce ochratoxin A and the results with A. carbonarius showed that this transgenic strain produced similar concentrations of this secondary metabolite. This is the first report on the in planta expression of fluorescent proteins that should be useful to study the internal plant colonization patterns of two ochratoxigenic species in the Aspergillus section Nigri. © 2013.

  4. Constitutive expression of CaPLA1 conferred enhanced growth and grain yield in transgenic rice plants.

    Science.gov (United States)

    Park, Ki Youl; Kim, Eun Yu; Seo, Young Sam; Kim, Woo Taek

    2016-03-01

    Phospholipids are not only important components of cell membranes, but participate in diverse processes in higher plants. In this study, we generated Capsicum annuum phospholipiase A1 (CaPLA1) overexpressing transgenic rice (Oryza sativa L.) plants under the control of the maize ubiquitin promoter. The T4 CaPLA1-overexpressing rice plants (Ubi:CaPLA1) had a higher root:shoot mass ratio than the wild-type plants in the vegetative stage. Leaf epidermal cells from transgenic plants had more cells than wild-type plants. Genes that code for cyclin and lipid metabolic enzymes were up-regulated in the transgenic lines. When grown under typical paddy field conditions, the transgenic plants produced more tillers, longer panicles and more branches per panicle than the wild-type plants, all of which resulted in greater grain yield. Microarray analysis suggests that gene expressions that are related with cell proliferation, lipid metabolism, and redox state were widely altered in CaPLA1-overexpressing transgenic rice plants. Ubi:CaPLA1 plants had a reduced membrane peroxidation state, as determined by malondialdehyde and conjugated diene levels and higher peroxidase activity than wild-type rice plants. Furthermore, three isoprenoid synthetic genes encoding terpenoid synthase, hydroxysteroid dehydrogenase and 3-hydroxy-3-methyl-glutaryl-CoA reductase were up-regulated in CaPLA1-overexpressing plants. We suggest that constitutive expression of CaPLA1 conferred increased grain yield with enhanced growth in transgenic rice plants by alteration of gene activities related with cell proliferation, lipid metabolism, membrane peroxidation state and isoprenoid biosynthesis.

  5. Increased skin barrier disruption by sodium lauryl sulfate in mice expressing a constitutively active STAT6 in T cells.

    Science.gov (United States)

    DaSilva, Sonia C; Sahu, Ravi P; Konger, Raymond L; Perkins, Susan M; Kaplan, Mark H; Travers, Jeffrey B

    2012-01-01

    Atopic dermatitis (AD) is a pruritic, chronic inflammatory skin disease that affects 10-20% of children and 1-3% of adults worldwide. Recent studies have indicated that the ability of Th2 cytokines, such as interleukin-4 (IL-4) to regulate skin barrier function may be a predisposing factor for AD development. The present studies examined the ability of increased Th2 activity to affect cutaneous barrier function in vivo and epidermal thickening. Mice that express a constitutively active Signal Transducer and Activator of Transcription 6 (STAT6VT) have increased Th2 cells and a predisposition to allergic inflammation were used in these studies, they demonstrate that topical treatment with the irritant sodium lauryl sulfate (SLS) caused increased transepidermal water loss and epidermal thickening in STAT6VT mice over similarly treated wild-type mice. The proliferation marker Ki-67 was increased in the epidermis of STAT6VT compared to the wild-type mice. However, these differences do not appear to be linked to the addition of an irritant as control-treated STAT6VT skin also exhibited elevated Ki-67 levels, suggesting that the increased epidermal thickness in SLS-treated STAT6VT mice is primarily driven by epidermal cell hypertrophy rather than an increase in cellular proliferation. Our results suggest that an environment with increased Th2 cytokines results in abnormal responses to topical irritants.

  6. Association of increased radiocurability of murine carcinomas with low constitutive expression of p21{sup WAF1/CIP1} protein

    Energy Technology Data Exchange (ETDEWEB)

    Akimoto, Tetsuo; Seong, Jinsil; Hunter, Nancy R; Buchmiller, Lara; Mason, Kathy; Milas, Luka

    1999-05-01

    Purpose: The study investigated whether basal, constitutive levels of p21{sup WAF1/CIP1} protein in murine carcinomas are related to in vivo tumor radioresponse. The study is based on recent observations demonstrating that in vitro cancer cell lines are resistant to cytotoxic drugs when they express high basal levels of p21{sup WAF1/CIP1} protein, and that the loss of the p21 gene in the HCT116 human colorectal cancer cell line results in increased radioresponse of xenografts derived from that cell line. Methods and Materials: Protein levels of p21{sup WAF1/CIP1}, p53, bax, and bcl-2 were determined in 8 carcinomas (3 mammary carcinomas designated MCa-4, MCa-29, and MCa-35, 2 squamous cell carcinomas designated SCC-IV and SCC-VII, ovarian adenocarcinoma OCa-I, hepatocarcinoma HCa-I, and adenosquamous carcinoma ACa-SG) syngeneic to C3Hf/Kam mice using Western blot analysis. The tumors, growing in the right hind legs of mice, were 8 mm in diameter at the time of analysis. These tumors greatly differ in their radioresponse, assessed by TCD50 assay, and in their susceptibility to radiation-induced apoptosis. Results: Protein levels of these oncogenes varied among tumors, with p21{sup WAF1/CIP1} showing the greatest variation: its mean densitometric value ranged from 1 to 19. Bcl-2 levels also showed broad variation in densitometric values, from 1 to 10. In comparison, bax and p53 (7 of 8 tumors contained wild-type p53) varied much less among different tumor types; their variation was within a 5-fold range, and the level of p53 was similar in 6 of 8 tumors. Tumor radioresponse correlated significantly (R = 0.77, p = 0.02) only with the magnitude of p21{sup WAF1/CIP1}expression: tumors with high levels of p21{sup WAF1/CIP1}were less radiocurable than those with lower levels. Tumor radiocurability showed a significant positive correlation (p = 0.02) with the extent of radiation-induced apoptosis, indicating that tumors that responded to radiation with higher percentages

  7. Comparison of constitutive and thiabendazole-induced expression of five cytochrome P450 genes in fourth-stage larvae of Haemonchus contortus isolates with different drug susceptibility identifies one gene with high constitutive expression in a multi-resistant isolate

    Directory of Open Access Journals (Sweden)

    Esra Yilmaz

    2017-12-01

    Full Text Available Benzimidazoles (BZs remain amongst the most widely used anthelmintic drug classes against gastro-intestinal nematode infections, although their efficacy is increasingly compromised by resistance. The primary underlying mechanisms for BZ resistance are single-nucleotide polymorphisms (SNPs in the isotype 1 β-tubulin gene causing the substitutions F167Y, E198A or F200Y. However, resistance is believed to be multi-genic and previous studies have shown that isolates carrying 90–100% F200Y can vary considerably in their resistance level in the egg hatch assay (EHA. Cytochrome P450 monooxygenases (CYPs are associated with drug resistance in mammals and arthropods and have been considered as mediators of anthelmintic resistance. In Caenorhabditis elegans, several members of the CYP34/35 and CYP31 families are BZ and/or xenobiotic inducible and thiabendazole (TBZ is metabolised by CYP35D1. Here, expression of all 5 CYPs closely related to the C. elegans CYP34/35 and CYP31 families was investigated in fourth-stage larvae of two susceptible and three BZ-resistant Haemonchus contortus isolates following in vitro exposure to TBZ for 3 and 6 h using real-time RT-PCR. The resistance status of all isolates was determined using EHAs and quantification of resistance-associated β-tubulin SNPs using pyrosequencing. While none of the CYPs was TBZ inducible, constitutive expression of CYP34/35 family member HCOI100383400 was significantly 2.4–3.7-fold higher in the multi-drug resistant WR isolate with the strongest BZ resistance phenotype compared to susceptible and intermediate-level BZ-resistant isolates. Although this increase is only moderate, HCOI100383400 might still be involved in high-level BZ resistance by further decreasing susceptibility in isolates already carrying 100% of a β-tubulin SNP causing BZ resistance. Lower transcript levels were observed for all CYPs in the intermediately resistant IRE isolate in comparison to the susceptible Hc

  8. Constitutive expression of feedback-insensitive cystathionine γ-synthase increases methionine levels in soybean leaves and seeds

    Institute of Scientific and Technical Information of China (English)

    YU Yang; HOU Wen-sheng; YaeI Hacham; SUN Shi; WU Cun-xiang; Ifat Matityahu; SONG Shikui; RacheI Amir; HAN Tian-fu

    2018-01-01

    Soybean (Glycine max (L.) Merr.) is a major crop that provides plant-origin protein and oil for humans and livestock. Although the soybean vegetative tissues and seeds provide a major source of high-quality protein, they suffer from low concentration of an essential sulfur-containing amino acid, methionine, which significantly limits their nutritional quality. The level of methionine is mainly controlled by the first unique enzyme of methionine synthesis, cystathione γ-synthase (CGS). Aiming to elevate methionine level in vegetative tissues and seeds, we constitutively over-expressed a feedback-insensitive Arabidopsis CGS (AtD-CGS) in soybean cultivars, Zigongdongdou (ZD) and Jilinxiaoli 1 (JX). The levels of soluble methionine increased remarkably in leaves of transgenic soybeans compared to wild-type plants (6.6- and 7.3-fold in two transgenic ZD lines, and 3.7-fold in one transgenic JX line). Furthermore, the total methionine contents were significantly increased in seeds of the transgenic ZD lines (1.5- to 4.8-fold increase) and the transgenic JX lines (1.3- to 2.3-fold increase) than in the wild type. The protein contents of the transgenic soybean seeds were significantly elevated compared to the wild type, suggesting that the scarcity of methionine in soybeans may limit protein accumulation in soybean seeds. The increased protein content did not alter the profile of major storage proteins in the seeds. Generally, this study provides a promising strategy to increase the levels of methionine and protein in soybean through the breeding programs.

  9. Impairments in cognition and neural precursor cell proliferation in mice expressing constitutively active glycogen synthase kinase-3

    Directory of Open Access Journals (Sweden)

    Marta ePardo

    2015-03-01

    Full Text Available ABSTRACTBrain glycogen synthase kinase-3 (GSK3 is hyperactive in several neurological conditions that involve impairments in both cognition and neurogenesis. This raises the hypotheses that hyperactive GSK3 may directly contribute to impaired cognition, and that this may be related to deficiencies in neural precursor cells (NPC. To study the effects of hyperactive GSK3 in the absence of disease influences, we compared adult hippocampal NPC proliferation and performance in three cognitive tasks in male and female wild-type mice and GSK3 knockin mice, which express constitutively active GSK3. NPC proliferation was ~40% deficient in both male and female GSK3 knockin mice compared with wild-type mice. Environmental enrichment (EE increased NPC proliferation in male, but not female, GSK3 knockin mice and wild-type mice. Male and female GSK3 knockin mice exhibited impairments in novel object recognition, temporal order memory, and coordinate spatial processing compared with gender-matched wild-type mice. EE restored impaired novel object recognition and temporal ordering in both sexes of GSK3 knockin mice, indicating that this repair was not dependent on NPC proliferation, which was not increased by EE in female GSK3 knockin mice. Acute 1 hr pretreatment with the GSK3 inhibitor TDZD-8 also improved novel object recognition and temporal ordering in male and female GSK3 knockin mice. These findings demonstrate that hyperactive GSK3 is sufficient to impair adult hippocampal NPC proliferation and to impair performance in three cognitive tasks in both male and female mice, but these changes in NPC proliferation do not directly regulate novel object recognition and temporal ordering tasks.

  10. A Bacterial Biosensor for Oxidative Stress Using the Constitutively Expressed Redox-Sensitive Protein roGFP2

    Directory of Open Access Journals (Sweden)

    Carlos R. Arias-Barreiro

    2010-06-01

    Full Text Available A highly specific, high throughput-amenable bacterial biosensor for chemically induced cellular oxidation was developed using constitutively expressed redox-sensitive green fluorescent protein roGFP2 in E. coli (E. coli-roGFP2. Disulfide formation between two key cysteine residues of roGFP2 was assessed using a double-wavelength ratiometric approach. This study demonstrates that only a few minutes were required to detect oxidation using E. coli-roGFP2, in contrast to conventional bacterial oxidative stress sensors. Cellular oxidation induced by hydrogen peroxide, menadione, sodium selenite, zinc pyrithione, triphenyltin and naphthalene became detectable after 10 seconds and reached the maxima between 80 to 210 seconds, contrary to Cd2+, Cu2+, Pb2+, Zn2+ and sodium arsenite, which induced the oxidation maximum immediately. The lowest observable effect concentrations (in ppm were determined as 1.0 x 10−7 (arsenite, 1.0 x 10−4 (naphthalene, 1.0 x 10−4 (Cu2+, 3.8 x 10−4 (H2O2, 1.0 x 10−3 (Cd2+, 1.0 x 10−3 (Zn2+, 1.0 x 10−2 (menadione, 1.0 (triphenyltin, 1.56 (zinc pyrithione, 3.1 (selenite and 6.3 (Pb2+, respectively. Heavy metal-induced oxidation showed unclear response patterns, whereas concentration-dependent sigmoid curves were observed for other compounds. In vivo GSH content and in vitro roGFP2 oxidation assays together with E. coli-roGFP2 results suggest that roGFP2 is sensitive to redox potential change and thiol modification induced by environmental stressors. Based on redox-sensitive technology, E. coli-roGFP2 provides a fast comprehensive detection system for toxicants that induce cellular oxidation.

  11. Up-regulation of phosphoinositide metabolism in tobacco cells constitutively expressing the human type I inositol polyphosphate 5-phosphatase

    Science.gov (United States)

    Perera, Imara Y.; Love, John; Heilmann, Ingo; Thompson, William F.; Boss, Wendy F.; Brown, C. S. (Principal Investigator)

    2002-01-01

    To evaluate the impact of suppressing inositol 1,4,5-trisphosphate (InsP(3)) in plants, tobacco (Nicotiana tabacum) cells were transformed with the human type I inositol polyphosphate 5-phosphatase (InsP 5-ptase), an enzyme which specifically hydrolyzes InsP(3). The transgenic cell lines showed a 12- to 25-fold increase in InsP 5-ptase activity in vitro and a 60% to 80% reduction in basal InsP(3) compared with wild-type cells. Stimulation with Mas-7, a synthetic analog of the wasp venom peptide mastoparan, resulted in an approximately 2-fold increase in InsP(3) in both wild-type and transgenic cells. However, even with stimulation, InsP(3) levels in the transgenic cells did not reach wild-type basal values, suggesting that InsP(3) signaling is compromised. Analysis of whole-cell lipids indicated that phosphatidylinositol 4,5-bisphosphate (PtdInsP(2)), the lipid precursor of InsP(3), was greatly reduced in the transgenic cells. In vitro assays of enzymes involved in PtdInsP(2) metabolism showed that the activity of the PtdInsP(2)-hydrolyzing enzyme phospholipase C was not significantly altered in the transgenic cells. In contrast, the activity of the plasma membrane PtdInsP 5 kinase was increased by approximately 3-fold in the transgenic cells. In vivo labeling studies revealed a greater incorporation of (32)P into PtdInsP(2) in the transgenic cells compared with the wild type, indicating that the rate of PtdInsP(2) synthesis was increased. These studies show that the constitutive expression of the human type I InsP 5-ptase in tobacco cells leads to an up-regulation of the phosphoinositide pathway and highlight the importance of PtdInsP(2) synthesis as a regulatory step in this system.

  12. The Grape VlWRKY3 Gene Promotes Abiotic and Biotic Stress Tolerance in Transgenic Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Rongrong Guo

    2018-04-01

    Full Text Available WRKY transcription factors are known to play important roles in plant responses to various abiotic and biotic stresses. The grape WRKY gene, WRKY3 was previously reported to respond to salt and drought stress, as well as methyl jasmonate and ethylene treatments in Vitis labrusca × V. vinifera cv. ‘Kyoho.’ In the current study, WRKY3 from the ‘Kyoho’ grape cultivar was constitutively expressed in Arabidopsis thaliana under control of the cauliflower mosaic virus 35S promoter. The 35S::VlWRKY3 transgenic A. thaliana plants showed improved salt and drought stress tolerance during the germination, seedling and the mature plant stages. Various physiological traits related to abiotic stress responses were evaluated to gain further insight into the role of VlWRKY3, and it was found that abiotic stress caused less damage to the transgenic seedlings than to the wild-type (WT plants. VlWRKY3 over-expression also resulted in altered expression levels of abiotic stress-responsive genes. Moreover, the 35S::VlWRKY3 transgenic A. thaliana lines showed improved resistance to Golovinomyces cichoracearum, but increased susceptibility to Botrytis cinerea, compared with the WT plants. Collectively, these results indicate that VlWRKY3 plays important roles in responses to both abiotic and biotic stress, and modification of its expression may represent a strategy to enhance stress tolerance in crops.

  13. Tobacco plants respond to the constitutive expression of the tospovirus movement protein Nsm with a heat-reversible sealing of plasmodesmata that impairs development

    NARCIS (Netherlands)

    Rinne, P.L.H.; Boogaard, van den R.; Mensink, G.J.; Kopperud, C.; Kormelink, R.J.M.; Goldbach, R.W.; Schoot, van der C.

    2005-01-01

    Viral infection often results in typical symptoms, the biological background of which has remained elusive. We show that constitutive expression of the NSM viral movement protein (MP) of tomato spotted wilt virus in Nicotiana tabacum is sufficient to induce severe, infection-like symptoms, including

  14. Constitutive expression of tert in thymocytes leads to increased incidence and dissemination of T-cell lymphoma in Lck-Tert mice.

    Science.gov (United States)

    Canela, Andrés; Martín-Caballero, Juan; Flores, Juana M; Blasco, María A

    2004-05-01

    Here we describe a new mouse model with constitutive expression of the catalytic subunit of telomerase (Tert) targeted to thymocytes and peripheral T cells (Lck-Tert mice). Two independent Lck-Tert mouse lines showed higher incidences of spontaneous T-cell lymphoma than the corresponding age-matched wild-type controls, indicating that constitutive expression of Tert promotes lymphoma. Interestingly, T-cell lymphomas in Lck-Tert mice were more disseminated than those in wild-type controls and affected both lymphoid and nonlymphoid tissues, while nonlymphoid tissues were never affected with lymphoma in age-matched wild-type controls. Importantly, these roles of Tert constitutive expression in promoting tumor progression and dissemination were independent of the role of telomerase in telomere length maintenance, since telomere length distributions on a single-cell basis were identical in Lck-Tert and wild-type thymocytes. Finally, Tert constitutive expression did not interfere with telomere capping in Lck-Tert primary thymocytes, although it resulted in greater chromosomal instability upon gamma irradiation in Lck-Tert primary lymphocytes than in controls, suggesting that Tert overexpression may interfere with the cellular response to DNA damage.

  15. Sequence and RT-PCR expression analysis of two peroxidases from Arabidopsis thaliana belonging to a novel evolutionary branch of plant peroxidases.

    Science.gov (United States)

    Kjaersgård, I V; Jespersen, H M; Rasmussen, S K; Welinder, K G

    1997-03-01

    cDNA clones encoding two new Arabidopsis thaliana peroxidases, ATP 1a and ATP 2a, have been identified by searching the Arabidopsis database of expressed sequence tags (dbEST). They represent a novel branch of hitherto uncharacterized plant peroxidases which is only 35% identical in amino acid sequence to the well characterized group of basic plant peroxidases represented by the horseradish (Armoracia rusticana) isoperoxidases HRP C, HRP E5 and the similar Arabidopsis isoperoxidases ATP Ca, ATP Cb, and ATP Ea. However ATP 1a is 87% identical in amino acid sequence to a peroxidase encoded by an mRNA isolated from cotton (Gossypium hirsutum). As cotton and Arabidopsis belong to rather diverse families (Malvaceae and Crucifereae, respectively), in contrast with Arabidopsis and horseradish (both Crucifereae), the high degree of sequence identity indicates that this novel type of peroxidase, albeit of unknown function, is likely to be widespread in plant species. The atp 1 and atp 2 types of cDNA sequences were the most redundant among the 28 different isoperoxidases identified among about 200 peroxidase encoding ESTs. Interestingly, 8 out of totally 38 EST sequences coding for ATP 1 showed three identical nucleotide substitutions. This variant form is designated ATP 1b. Similarly, six out of totally 16 EST sequences coding for ATP 2 showed a number of deletions and nucleotide changes. This variant form is designated ATP 2b. The selected EST clones are full-length and contain coding regions of 993 nucleotides for atp 1a, and 984 nucleotides for atp 2a. These regions show 61% DNA sequence identity. The predicted mature proteins ATP 1a, and ATP 2a are 57% identical in sequence and contain the structurally and functionally important residues, characteristic of the plant peroxidase superfamily. However, they do show two differences of importance to peroxidase catalysis: (1) the asparagine residue linked with the active site distal histidine via hydrogen bonding is absent

  16. Seeing red; the development of pON.mCherry, a broad-host range constitutive expression plasmid for Gram-negative bacteria.

    Directory of Open Access Journals (Sweden)

    Michael J Gebhardt

    Full Text Available The development of plasmid-mediated gene expression control in bacteria revolutionized the field of bacteriology. Many of these expression control systems rely on the addition of small molecules, generally metabolites or non-metabolized analogs thereof, to the growth medium to induce expression of the genes of interest. The paradigmatic example of an expression control system is the lac system from Escherichia coli, which typically relies on the Ptac promoter and the Lac repressor, LacI. In many cases, however, constitutive gene expression is desired, and other experimental approaches require the coordinated control of multiple genes. While multiple systems have been developed for use in E. coli and its close relatives, the utility and/or functionality of these tools does not always translate to other species. For example, for the Gram-negative pathogen, Legionella pneumophila, a causative agent of Legionnaires' Disease, the aforementioned Ptac system represents the only well-established expression control system. In order to enhance the tools available to study bacterial gene expression in L. pneumophila, we developed a plasmid, pON.mCherry, which confers constitutive gene expression from a mutagenized LacI binding site. We demonstrate that pON.mCherry neither interferes with other plasmids harboring an intact LacI-Ptac expression system nor alters the growth of Legionella species during intracellular growth. Furthermore, the broad-host range plasmid backbone of pON.mCherry allows constitutive gene expression in a wide variety of Gram-negative bacterial species, making pON.mCherry a useful tool for the greater research community.

  17. Arabidopsis thaliana peroxidase N

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ostergaard, L

    2000-01-01

    The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C...

  18. Differential expression analysis of boron transporters and some stress-related genes in response to 24-epibrassinolide and boron by semi-quantitative RT-PCR in Arabidopsis thaliana (L. Heynh

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    Surgun Yonca

    2016-01-01

    Full Text Available Plant steroidal hormones, brassinosteroids (BRs, promote plant developmental processes and enhance tolerance to several abiotic stresses including high boron (B stress. To examine the possible role of BR in high B-induced stress at the transcriptional level, we investigated the response of B transporter genes (BOR1-4, high B-induced genes (MATE, Hsp-like, BR-induced genes (Hsp70-4, Hsp90-1 and other stress-related genes (LTI/COR78, LEA4-5 upon exogenous treatments of 24-epibrassinolide (EBL on Arabidopsis thaliana (L. Heynh exposed to high concentrations of boric acid (BA using semi-quantitative RT-PCR. BA treatments led to down regulation of BOR1 and BOR3 genes in leaf and root tissues and higher concentration of EBL further decreased expression of these genes in roots. The expression of high B-induced genes was observed to be upregulated by 1 μM EBL treatment under high B stress in both tissues of the seedlings. The upregulation of BR-induced genes were clearly evident in root tissues co-treated with 1 μM EBL and BA as compared to BA alone. Higher concentration of EBL was found to be more effective in increasing expression of LTI/COR78 gene in root and LEA4-5 gene in shoot tissues. To our knowledge, this is the first report how exogenous application of EBL modulates high B stress responses at molecular level in model plant Arabidopsis thaliana.

  19. IFN-ε is constitutively expressed by cells of the reproductive tract and is inefficiently secreted by fibroblasts and cell lines.

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    Pascale Hermant

    Full Text Available Type-I interferons (IFNs form a large family of cytokines that primarily act to control the early development of viral infections. Typical type-I IFN genes, such as those encoding IFN-α or IFN-β are upregulated by viral infection in many cell types. In contrast, the gene encoding IFN-ε was reported to be constitutively expressed by cells of the female reproductive tract and to contribute to the protection against vaginal infections with herpes simplex virus 2 and Chlamydia muridarum. Our data confirm the lack of induction of IFN-ε expression after viral infection and the constitutive expression of IFN-ε by cells of the female but also of the male reproductive organs. Interestingly, when expressed from transfected expression plasmids in 293T, HeLa or Neuro2A cells, the mouse and human IFN-ε precursors were inefficiently processed and secretion of IFN-ε was minimal. Analysis of chimeric constructs produced between IFN-ε and limitin (IFN-ζ showed that both the signal peptide and the mature moiety of IFN-ε contribute to poor processing of the precursor. Immunofluorescent detection of FLAG-tagged IFN-ε in transfected cells suggested that IFN-ε and chimeric proteins were defective for progression through the secretory pathway. IFN-ε did not, however, act intracellularly and impart an antiviral state to producing cells. Given the constitutive expression of IFN-ε in specialized cells and the poor processing of IFN-ε precursor in fibroblasts and cell lines, we hypothesize that IFN-ε secretion may require a co-factor specifically expressed in cells of the reproductive organs, that might secure the system against aberrant release of this IFN.

  20. Heterologous expression of the Arabidopsis etr1-1 allele inhibits the senescence of carnation flowers

    NARCIS (Netherlands)

    Bovy, A.G.; Angenent, G.C.; Dons, H.J.M.; Altvorst, van A.

    1999-01-01

    The Arabidopsis thaliana etr1-1 allele, capable of conferring ethylene insensitivity in a heterologous host, was introduced into transgenic carnation plants. This gene was expressed under control of either its own promoter, the constitutive CaMV 35S promoter or the flower-specific petunia FBP1

  1. Constitutive STAT3-activation in Sezary syndrome: tyrphostin AG490 inhibits STAT3-activation, interleukin-2 receptor expression and growth of leukemic Sezary cells

    DEFF Research Database (Denmark)

    Eriksen, K W; Kaltoft, K; Mikkelsen, G

    2001-01-01

    are IL-2Ralpha negative. An aberrant expression of IL-2Ralpha has recently been described in cutaneous T-cell lymphoma (CTCL). Here, we study the regulation of IL-2Ralpha expression and STATs in a tumor cell line obtained from peripheral blood from a patient with Sezary syndrome (SS), a leukemic variant...... of CTCL. We show that (1) STAT3 (a transcription factor known to regulate IL-2Ralpha transcription) is constitutively tyrosine-phosphorylated in SS tumor cells, but not in non-malignant T cells; (2) STAT3 binds constitutively to a STAT-binding sequence in the promotor of the IL-2Ralpha gene; (3) the Janus...... kinase inhibitor, tyrphostine AG490, inhibits STAT3 activation, STAT3 DNA binding, and IL-2Ralpha mRNA and protein expression in parallel; and (4) tyrphostine AG490 inhibits IL-2 driven mitogenesis and triggers apoptosis in SS tumor cells. In conclusion, we provide the first example of a constitutive...

  2. Defective interleukin-4/Stat6 activity correlates with increased constitutive expression of negative regulators SOCS-3, SOCS-7, and CISH in colon cancer cells.

    Science.gov (United States)

    Liu, Xiao Hong; Xu, Shuang Bing; Yuan, Jia; Li, Ben Hui; Zhang, Yan; Yuan, Qin; Li, Pin Dong; Li, Feng; Zhang, Wen Jie

    2009-12-01

    Interleukin-4 (IL-4)-induced Stat6 activities (phenotypes) vary among human cancer cells, of which the HT-29 cell line carries an active Stat6(high) phenotype, while Caco-2 carries a defective Stat6(null) phenotype, respectively. Cancer cells with Stat6(high) show resistance to apoptosis and exaggerated metastasis, suggesting the clinical significance of Stat6 phenotypes. We previously showed that Stat6(high) HT-29 cells exhibited low constitutive expression of Stat6-negative regulators SOCS-1 and SHP-1 because of gene hypermethylation. This study further examined the constitutive expression of other closely related SOCS family numbers including SOCS-3, SOCS-5, SOCS-7, and CISH using RT-PCR. Similar to SOCS-1 and SHP-1, Stat6(high) HT-29 cells expressed low constitutive mRNA of SOCS-3, SOCS-7, and CISH than Stat6(null) Caco-2 cells. Interestingly, DNA demethylation using 5-aza-2'-deoxycytidine in HT-29 cells up-regulated mRNA expression of the above genes, indicating a hypermethylation status, which was confirmed by methylation-specific sequencing in selected SOCS-3 gene. Furthermore, defective Stat6(null) Caco-2 exhibited impaired phosphorylation of Stat6 after IL-4 stimulation by flow cytometry, in keeping with the notion of an over-performed negative regulation. The findings that IL-4/Stat6 phenotypes show differential expression of multiple negative regulators suggest a model that a collective force of powerful negative regulators, directly and indirectly, acts on Stat6 activation, which may result in differential Stat6 phenotypes.

  3. The Physiological and Biochemical Mechanisms Providing the Increased Constitutive Cold Resistance in the Potato Plants, Expressing the Yeast SUC2 Gene Encoding Apoplastic Invertase

    Directory of Open Access Journals (Sweden)

    A.N. Deryabin

    2016-05-01

    Full Text Available The expression of heterologous genes in plants is an effective method to improve our understanding of plant resistance mechanisms. The purpose of this work was to investigate the involvement of cell-wall invertase and apoplastic sugars into constitutive cold resistance of potato (Solanum tuberosum L., cv. Dйsirйe plants, which expressed the yeast SUC2 gene encoding apoplastic invertase. WT-plants of a potato served as the control. The increase in the essential cell-wall invertase activity in the leaves of transformed plants indicates significant changes in the cellular carbohydrate metabolism and regulatory function of this enzyme. The activity of yeast invertase changed the composition of intracellular sugars in the leaves of the transformed potato plant. The total content of sugars (sucrose, glucose, fructose in the leaves and apoplast was higher in the transformants, in comparison by WT-plants. Our data indicate higher constitutive resistance of transformants to severe hypothermia conditions compared to WT-plants. This fact allows us to consider cell-wall invertase as a enzyme of carbohydrate metabolism playing an important regulatory role in the metabolic signaling upon forming increased plant resistance to low temperature. Thus, the potato line with the integrated SUC2 gene is a convenient tool to study the role of the apoplastic invertase and the products of its activity during growth, development and formation constitutive resistance to hypothermia.

  4. The in vitro and in vivo effects of constitutive light expression on a bioluminescent strain of the mouse enteropathogen Citrobacter rodentium

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    Hannah M. Read

    2016-06-01

    Full Text Available Bioluminescent reporter genes, such as those from fireflies and bacteria, let researchers use light production as a non-invasive and non-destructive surrogate measure of microbial numbers in a wide variety of environments. As bioluminescence needs microbial metabolites, tagging microorganisms with luciferases means only live metabolically active cells are detected. Despite the wide use of bioluminescent reporter genes, very little is known about the impact of continuous (also called constitutive light expression on tagged bacteria. We have previously made a bioluminescent strain of Citrobacter rodentium, a bacterium which infects laboratory mice in a similar way to how enteropathogenic Escherichia coli (EPEC and enterohaemorrhagic E. coli (EHEC infect humans. In this study, we compared the growth of the bioluminescent C. rodentium strain ICC180 with its non-bioluminescent parent (strain ICC169 in a wide variety of environments. To understand more about the metabolic burden of expressing light, we also compared the growth profiles of the two strains under approximately 2,000 different conditions. We found that constitutive light expression in ICC180 was near-neutral in almost every non-toxic environment tested. However, we also found that the non-bioluminescent parent strain has a competitive advantage over ICC180 during infection of adult mice, although this was not enough for ICC180 to be completely outcompeted. In conclusion, our data suggest that constitutive light expression is not metabolically costly to C. rodentium and supports the view that bioluminescent versions of microbes can be used as a substitute for their non-bioluminescent parents to study bacterial behaviour in a wide variety of environments.

  5. Prostacyclin Synthase: Upregulation during Renal Development and in Glomerular Disease as well as Its Constitutive Expression in Cultured Human Mesangial Cells

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    Thomas Klein

    2015-01-01

    Full Text Available Prostacyclin (PGI2 plays a critical role in nephrogenesis and renal physiology. However, our understanding of how prostacyclin release in the kidney is regulated remains poorly defined. We studied expression of prostacyclin synthase (PGIS in developing and adult human kidneys, and also in selected pediatric renal diseases. We also examined PGI2 formation in human mesangial cells in vitro. We observed abundant expression of PGIS in the nephrogenic cortex in humans and in situ hybridization revealed an identical pattern in mice. In the normal adult kidney, PGIS-immunoreactive protein and mRNA appear to localize to mesangial fields and endothelial and smooth muscle cells of arteries and peritubular capillaries. In kidney biopsies taken from pediatric patients, enhanced expression of PGIS-immunoreactive protein was noted mainly in endothelial cells of patients with IgA-nephropathy. Cultured human mesangial cells produce primarily PGI2 and prostaglandin E2, followed by prostaglandin F2α Cytokine stimulation increased PGI2 formation 24-fold. Under these conditions expression of PGIS mRNA and protein remained unaltered whereas mRNA for cyclooxygenase-2 was markedly induced. In contrast to its constitutive expression in vitro, renal expression of prostacyclin-synthase appears to be regulated both during development and in glomerular disease. Further research is needed to identify the factors involved in regulation of PGIS-expression.

  6. Constitutive expression of TNF-related activation-induced cytokine (TRANCE/receptor activating NF-κB ligand (RANK-L by rat plasmacytoid dendritic cells.

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    Thomas Anjubault

    Full Text Available Plasmacytoid dendritic cells (pDCs are a subset of DCs whose major function relies on their capacity to produce large amount of type I IFN upon stimulation via TLR 7 and 9. This function is evolutionary conserved and place pDC in critical position in the innate immune response to virus. Here we show that rat pDC constitutively express TNF-related activation-induced cytokine (TRANCE also known as Receptor-activating NF-κB ligand (RANKL. TRANCE/RANKL is a member of the TNF superfamily which plays a central role in osteoclastogenesis through its interaction with its receptor RANK. TRANCE/RANK interaction are also involved in lymphoid organogenesis as well as T cell/DC cross talk. Unlike conventional DC, rat CD4(high pDC were shown to constitutively express TRANCE/RANKL both at the mRNA and the surface protein level. TRANCE/RANKL was also induced on the CD4(low subsets of pDC following activation by CpG. The secreted form of TRANCE/RANKL was also produced by rat pDC. Of note, levels of mRNA, surface and secreted TRANCE/RANKL expression were similar to that observed for activated T cells. TRANCE/RANKL expression was found on pDC in all lymphoid organs as well blood and BM with a maximum expression in mesenteric lymph nodes. Despite this TRANCE/RANKL expression, we were unable to demonstrate in vitro osteoclastogenesis activity for rat pDC. Taken together, these data identifies pDC as novel source of TRANCE/RANKL in the immune system.

  7. Constitutional Conservatism

    Science.gov (United States)

    Berkowitz, Peter

    2009-01-01

    After their dismal performance in election 2008, conservatives are taking stock. As they examine the causes that have driven them into the political wilderness and as they explore paths out, they should also take heart. After all, election 2008 shows that America's constitutional order is working as designed. Indeed, while sorting out their errors…

  8. Genome-Wide Constitutively Expressed Gene Analysis and New Reference Gene Selection Based on Transcriptome Data: A Case Study from Poplar/Canker Disease Interaction

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    Jiaping Zhao

    2017-10-01

    Full Text Available A number of transcriptome datasets for differential expression (DE genes have been widely used for understanding organismal biology, but these datasets also contain untapped information that can be used to develop more precise analytical tools. With the use of transcriptome data generated from poplar/canker disease interaction system, we describe a methodology to identify candidate reference genes from high-throughput sequencing data. This methodology will improve the accuracy of RT-qPCR and will lead to better standards for the normalization of expression data. Expression stability analysis from xylem and phloem of Populus bejingensis inoculated with the fungal canker pathogen Botryosphaeria dothidea revealed that 729 poplar transcripts (1.11% were stably expressed, at a threshold level of coefficient of variance (CV of FPKM < 20% and maximum fold change (MFC of FPKM < 2.0. Expression stability and bioinformatics analysis suggested that commonly used house-keeping (HK genes were not the most appropriate internal controls: 70 of the 72 commonly used HK genes were not stably expressed, 45 of the 72 produced multiple isoform transcripts, and some of their reported primers produced unspecific amplicons in PCR amplification. RT-qPCR analysis to compare and evaluate the expression stability of 10 commonly used poplar HK genes and 20 of the 729 newly-identified stably expressed transcripts showed that some of the newly-identified genes (such as SSU_S8e, LSU_L5e, and 20S_PSU had higher stability ranking than most of commonly used HK genes. Based on these results, we recommend a pipeline for deriving reference genes from transcriptome data. An appropriate candidate gene should have a unique transcript, constitutive expression, CV value of expression < 20% (or possibly 30% and MFC value of expression <2, and an expression level of 50–1,000 units. Lastly, when four of the newly identified HK genes were used in the normalization of expression data for 20

  9. Facile high-throughput forward chemical genetic screening by in situ monitoring of glucuronidase-based reporter gene expression in Arabidopsis thaliana

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    Vivek eHalder

    2015-01-01

    Full Text Available The use of biologically active small molecules to perturb biological functions holds enormous potential for investigating complex signaling networks. However, in contrast to animal systems, the search for and application of chemical tools for basic discovery in the plant sciences, generally referred to as ‘chemical genetics’, has only recently gained momentum. In addition to cultured cells, the well-characterized, small-sized model plant Arabidopsis thaliana is suitable for cultivation in microplates, which allows employing diverse cell- or phenotype-based chemical screens. In such screens, a chemical’s bioactivity is typically assessed either through scoring its impact on morphological traits or quantifying molecular attributes such as enzyme or reporter activities. Here, we describe a facile forward chemical screening methodology for intact Arabidopsis seedlings harboring the β-glucuronidase (GUS reporter by directly quantifying GUS activity in situ with 4-methylumbelliferyl-β-D-glucuronide (4-MUG as substrate. The quantitative nature of this screening assay has an obvious advantage over the also convenient histochemical GUS staining method, as it allows application of statistical procedures and unbiased hit selection based on threshold values as well as distinction between compounds with strong or weak bioactivity. At the same time, the in situ bioassay is very convenient requiring less effort and time for sample handling in comparison to the conventional quantitative in vitro GUS assay using 4-MUG, as validated with several Arabidopsis lines harboring different GUS reporter constructs. To demonstrate that the developed assays is particularly suitable for large-scale screening projects, we performed a pilot screen for chemical activators or inhibitors of salicylic acid-mediated defense signaling using the Arabidopsis PR1p::GUS line. Importantly, the screening methodology provided here can be adopted for any inducible GUS reporter line.

  10. A large scale analysis of cDNA in Arabidopsis thaliana: generation of 12,028 non-redundant expressed sequence tags from normalized and size-selected cDNA libraries.

    Science.gov (United States)

    Asamizu, E; Nakamura, Y; Sato, S; Tabata, S

    2000-06-30

    For comprehensive analysis of genes expressed in the model dicotyledonous plant, Arabidopsis thaliana, expressed sequence tags (ESTs) were accumulated. Normalized and size-selected cDNA libraries were constructed from aboveground organs, flower buds, roots, green siliques and liquid-cultured seedlings, respectively, and a total of 14,026 5'-end ESTs and 39,207 3'-end ESTs were obtained. The 3'-end ESTs could be clustered into 12,028 non-redundant groups. Similarity search of the non-redundant ESTs against the public non-redundant protein database indicated that 4816 groups show similarity to genes of known function, 1864 to hypothetical genes, and the remaining 5348 are novel sequences. Gene coverage by the non-redundant ESTs was analyzed using the annotated genomic sequences of approximately 10 Mb on chromosomes 3 and 5. A total of 923 regions were hit by at least one EST, among which only 499 regions were hit by the ESTs deposited in the public database. The result indicates that the EST source generated in this project complements the EST data in the public database and facilitates new gene discovery.

  11. Constitutive expression of the xylanase inhibitor TAXI-III delays Fusarium head blight symptoms in durum wheat transgenic plants.

    Science.gov (United States)

    Moscetti, Ilaria; Tundo, Silvio; Janni, Michela; Sella, Luca; Gazzetti, Katia; Tauzin, Alexandra; Giardina, Thierry; Masci, Stefania; Favaron, Francesco; D'Ovidio, Renato

    2013-12-01

    Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.

  12. Constitutive transgene expression of Stem Cell Antigen-1 in the hair follicle alters the sensitivity to tumor formation and progression

    Directory of Open Access Journals (Sweden)

    Rikke Christensen

    2017-08-01

    Full Text Available The cell surface protein Stem Cell Antigen-1 (Sca-1 marks stem or progenitor cells in several murine tissues and is normally upregulated during cancer development. Although the specific function of Sca-1 remains unknown, Sca-1 seems to play a role in proliferation, differentiation and cell migration in a number of tissues. In the skin epithelium, Sca-1 is highly expressed in the interfollicular epidermis but is absent in most compartments of the hair follicle; however, the function of Sca-1 in the skin has not been investigated. To explore the role of Sca-1 in normal and malignant skin development we generated transgenic mice that express Sca-1 in the hair follicle stem cells that are normally Sca-1 negative. Development of hair follicles and interfollicular epidermis appeared normal in Sca-1 mutant mice; however, follicular induction of Sca-1 expression in bulge region and isthmus stem cells reduced the overall yield of papillomas in a chemical carcinogenesis protocol. Despite that fewer papillomas developed in transgenic mice a higher proportion of the papillomas underwent malignant conversion. These findings suggest that overexpression of Sca-1 in the hair follicle stem cells contributes at different stages of tumour development. In early stages, overexpression of Sca-1 decreases tumour formation while at later stages overexpression of Sca-1 seems to drive tumours towards malignant progression.

  13. Constitutive expression, purification and characterisation of pectin methylesterase from Aspergillus niger in Pichia pastoris for potential application in the fruit juice industry.

    Science.gov (United States)

    Jiang, Xiuping; Chen, Peng; Yin, Maolu; Yang, Qing

    2013-01-01

    Pectin methylesterase (PME) catalyses the hydrolysis of the methyl ester of pectin, yielding free carboxyl groups and methanol. PME is widely used in the food, cosmetic and pharmaceutical industries. PME from Aspergillus niger was constitutively expressed to a high level in the yeast Pichia pastoris. The recombinant PME was purified by a combination of ammonium sulfate fractionation and ion exchange chromatography, giving an overall yield of 28.0%. It appeared as a single band in sodium dodecyl sulfate polyacrylamide gel electrophoresis, with a molecular mass of about 45 kDa. Optimal activity of the enzyme occurred at a temperature of 50 °C and a pH of 4.7. The K(m), V(max) and k(cat) values of the enzyme with respect to pectin were 8.6 mmol L⁻¹ [Formula: See Text], 1.376 mmol min⁻¹ mg⁻¹ and 8.26 × 10² s⁻¹ respectively. Cations such as K⁺, Mg²⁺, Ni²⁺, Mn²⁺ and Co²⁺ slightly inhibited its activity, whereas Na⁺ had no effect. PME from A. niger was constitutively expressed to a high level in P. pastoris without methanol induction. The recombinant PME was purified and characterised and shown to be a good candidate for potential application in the fruit juice industry. Copyright © 2012 Society of Chemical Industry.

  14. Generation of a constitutively expressing Tetracycline repressor (TetR human embryonic stem cell line BJNhem20-TetR

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    Ronak Shetty

    2016-03-01

    Full Text Available Human embryonic stem cell line BJNhem20-TetR was generated using non-viral method. The construct pCAG-TetRnls was transfected using microporation procedure. BJNhem20-TetR can subsequently be transfected with any vector harbouring a TetO (Tet operator sequence to generate doxycycline based inducible line. For example, in human embryonic stem cells, the pSuperior based TetO system has been transfected into a TetR containing line to generate OCT4 knockdown cell line (Zafarana et al., 2009. Thus BJNhem20-TetR can be used as a tool to perturb gene expression in human embryonic stem cells.

  15. Biotic and abiotic stress tolerance in transgenic tomatoes by constitutive expression of S-adenosylmethionine decarboxylase gene.

    Science.gov (United States)

    Hazarika, Pranjal; Rajam, Manchikatla Venkat

    2011-04-01

    Recent findings have implicated the role of polyamines (putrescine, spermidine and spermine) in stress tolerance. Therefore, the present work was carried out with the goal of generating transgenic tomato plants with human S-adenosylmethionine decarboxylase (samdc) gene, a key gene involved in biosynthesis of polyamines, viz. spermidine and spermine and evaluating the transgenic plants for tolerance to both biotic and abiotic stresses. Several putative transgenic tomato plants with normal phenotype were obtained, and the transgene integration and expression was validated by PCR, Southern blot analysis and RT-PCR analysis, respectively. The transgenic plants exhibited high levels of polyamines as compared to the untransformed control plants. They also showed increased resistance against two important fungal pathogens of tomato, the wilt causing Fusarium oxysporum and the early blight causing Alternaria solani and tolerance to multiple abiotic stresses such as salinity, drought, cold and high temperature. These results suggest that engineering polyamine accumulation can confer tolerance to both biotic and abiotic stresses in plants.

  16. Stage 3 immature human natural killer cells found in secondary lymphoid tissue constitutively and selectively express the TH17 cytokine interleukin-22

    Science.gov (United States)

    Hughes, Tiffany; Becknell, Brian; McClory, Susan; Briercheck, Edward; Freud, Aharon G.; Zhang, Xiaoli; Mao, Hsiaoyin; Nuovo, Gerard; Yu, Jianhua

    2009-01-01

    Considerable functional heterogeneity within human natural killer (NK) cells has been revealed through the characterization of distinct NK-cell subsets. Accordingly, a small subset of CD56+NKp44+NK cells, termed NK-22 cells, was recently described within secondary lymphoid tissue (SLT) as IL-22− when resting, with a minor fraction of this population becoming IL-22+ when activated. Here we discover that the vast majority of stage 3 immature NK (iNK) cells in SLT constitutively and selectively express IL-22, a TH17 cytokine important for mucosal immunity, whereas earlier and later stages of NK developmental intermediates do not express IL-22. These iNK cells have a surface phenotype of CD34−CD117+CD161+CD94−, largely lack expression of NKp44 and CD56, and do not produce IFN-γ or possess cytolytic activity. In summary, stage 3 iNK cells are highly enriched for IL-22 and IL-26 messenger RNA, and IL-22 protein production, but do not express IL-17A or IL-17F. PMID:19244159

  17. Ectopic Expression of CsCTR1, a Cucumber CTR-Like Gene, Attenuates Constitutive Ethylene Signaling in an Arabidopsis ctr1-1 Mutant and Expression Pattern Analysis of CsCTR1 in Cucumber (Cucumis sativus

    Directory of Open Access Journals (Sweden)

    Beibei Bie

    2014-09-01

    Full Text Available The gaseous plant hormone ethylene regulates many aspects of plant growth, development and responses to the environment. Constitutive triple response 1 (CTR1 is a central regulator involved in the ethylene signal transduction pathway. To obtain a better understanding of this particular pathway in cucumber, the cDNA-encoding CTR1 (designated CsCTR1 was isolated from cucumber. A sequence alignment and phylogenetic analyses revealed that CsCTR1 has a high degree of homology with other plant CTR1 proteins. The ectopic expression of CsCTR1 in the Arabidopsis ctr1-1 mutant attenuates constitutive ethylene signaling of this mutant, suggesting that CsCTR1 indeed performs its function as negative regulator of the ethylene signaling pathway. CsCTR1 is constitutively expressed in all of the examined cucumber organs, including roots, stems, leaves, shoot apices, mature male and female flowers, as well as young fruits. CsCTR1 expression gradually declined during male flower development and increased during female flower development. Additionally, our results indicate that CsCTR1 can be induced in the roots, leaves and shoot apices by external ethylene. In conclusion, this study provides a basis for further studies on the role of CTR1 in the biological processes of cucumber and on the molecular mechanism of the cucumber ethylene signaling pathway.

  18. Constitutive expression of ftsZ overrides the whi developmental genes to initiate sporulation of Streptomyces coelicolor.

    Science.gov (United States)

    Willemse, Joost; Mommaas, A Mieke; van Wezel, Gilles P

    2012-03-01

    The filamentous soil bacteria Streptomyces undergo a highly complex developmental programme. Before streptomycetes commit themselves to sporulation, distinct morphological checkpoints are passed in the aerial hyphae that are subject to multi-level control by the whi sporulation genes. Here we show that whi-independent expression of FtsZ restores sporulation to the early sporulation mutants whiA, whiB, whiG, whiH, whiI and whiJ. Viability, stress resistance and high-resolution electron microscopy underlined that viable spores were formed. However, spores from sporulation-restored whiA and whiG mutants showed defects in DNA segregation/condensation, while spores from the complemented whiB mutant had increased stress sensitivity, perhaps as a result of changes in the spore sheath. In contrast to the whi mutants, normal sporulation of ssgB null mutants-which fail to properly localise FtsZ-could not be restored by enhancing FtsZ protein levels, forming spore-like bodies that lack spore walls. Our data strongly suggest that the whi genes control a decisive event towards sporulation of streptomycetes, namely the correct timing of developmental ftsZ transcription. The biological significance may be to ensure that sporulation-specific cell division will only start once sufficient aerial mycelium biomass has been generated. Our data shed new light on the longstanding question as to how whi genes control sporulation, which has intrigued scientists for four decades.

  19. Constitutive mRNA expression and protein activity levels of nine ABC efflux transporters in seven permanent cell lines derived from different tissues of rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Fischer, Stephan; Loncar, Jovica; Zaja, Roko; Schnell, Sabine; Schirmer, Kristin; Smital, Tvrtko; Luckenbach, Till

    2011-01-25

    Permanent fish cell lines have become common model systems for determining ecotoxicological effects of pollutants. For these cell lines little is known on the cellular active transport mechanisms that control the amount of a compound entering the cell, such as the MXR (multixenobiotic resistance) system mediated by ATP binding cassette (ABC) transport proteins. Therefore, for toxic evaluation of chemicals with those cells information on MXR is important. We here present data on constitutive mRNA expression and protein activity levels of a series of ABC efflux transporters in seven permanent cell lines derived from liver (RTL-W1; R1) and liver hepatoma (RTH-149), gill (RTgill-W1), gonad (RTG-2), gut (RTgutGC) and brain (RTbrain) of rainbow trout (Oncorhynchus mykiss). In addition to known transporters abcb1 (designated here abcb1a), abcb11, abcc1-3, abcc5 and abcg2, we quantified expression levels of a newly identified abcb1 isoform (abcb1b) and abcc4, previously unknown in trout. Quantitative real time PCR (qPCR) indicated that mRNA of the examined ABC transporters was constitutively expressed in all cell lines. Transporter mRNA expression patterns were similar in all cell lines, with expression levels of abcc transporters being 80 to over 1000 fold higher than for abcg2, abcb1a/b and abcb11 (abcc1-5>abcg2>abcb1a/b, 11). Transporter activity in the cell lines was determined by measuring uptake of transporter type specific fluorescent substrates in the presence of activity inhibitors. The combination of the ABCB1 and ABCC transporter substrate calcein-AM with inhibitors cyclosporine A, PSC833 and MK571 resulted in a concentration-dependent fluorescence increase of up to 3-fold, whereas reversin 205 caused a slight, but not concentration-dependent fluorescence increase. Accumulation of the dyes Hoechst 33342 and 2',7'-dichlorodihydrofluorescein diacetate was basically unchanged in the presence of Ko134 and taurocholate, respectively, indicating low Abcg2 and Abcb11

  20. Role of methyl salicylate on oviposition deterrence in Arabidopsis thaliana.

    Science.gov (United States)

    Groux, Raphaël; Hilfiker, Olivier; Gouhier-Darimont, Caroline; Peñaflor, Maria Fernanda Gomes Villalba; Erb, Matthias; Reymond, Philippe

    2014-07-01

    Plants attacked by herbivores have evolved different strategies that fend off their enemies. Insect eggs deposited on leaves have been shown to inhibit further oviposition through visual or chemical cues. In some plant species, the volatile methyl salicylate (MeSA) repels gravid insects but whether it plays the same role in the model species Arabidopsis thaliana is currently unknown. Here we showed that Pieris brassicae butterflies laid fewer eggs on Arabidopsis plants that were next to a MeSA dispenser or on plants with constitutively high MeSA emission than on control plants. Surprisingly, the MeSA biosynthesis mutant bsmt1-1 treated with egg extract was still repellent to butterflies when compared to untreated bsmt1-1. Moreover, the expression of BSMT1 was not enhanced by egg extract treatment but was induced by herbivory. Altogether, these results provide evidence that the deterring activity of eggs on gravid butterflies is independent of MeSA emission in Arabidopsis, and that MeSA might rather serve as a deterrent in plants challenged by feeding larvae.

  1. The Sporothrix schenckii Gene Encoding for the Ribosomal Protein L6 Has Constitutive and Stable Expression and Works as an Endogenous Control in Gene Expression Analysis

    Directory of Open Access Journals (Sweden)

    Elías Trujillo-Esquivel

    2017-09-01

    Full Text Available Sporothrix schenckii is one of the causative agents of sporotrichosis, a worldwide-distributed mycosis that affects humans and other mammals. The interest in basic and clinical features of this organism has significantly increased in the last years, yet little progress in molecular aspects has been reported. Gene expression analysis is a set of powerful tools that helps to assess the cell response to changes in the extracellular environment, the genetic networks controlling metabolic pathways, and the adaptation to different growth conditions. Most of the quantitative methodologies used nowadays require data normalization, and this is achieved measuring the expression of endogenous control genes. Reference genes, whose expression is assumed to suffer minimal changes regardless the cell morphology, the stage of the cell cycle or the presence of harsh extracellular conditions are commonly used as controls in Northern blotting assays, microarrays, and semi-quantitative or quantitative RT-PCR. Since the biology of the organisms is usually species specific, it is difficult to find a reliable group of universal genes that can be used as controls for data normalization in experiments addressing the gene expression, regardless the taxonomic classification of the organism under study. Here, we compared the transcriptional stability of the genes encoding for elongation factor 1A, Tfc1, a protein involved in transcription initiation on Pol III promoters, ribosomal protein L6, histone H2A, β-actin, β-tubulin, glyceraldehyde 3-phosphate dehydrogenase, UAF30, the upstream activating factor 30, and the transcription initiation factor TFIID subunit 10, during the fungal growth in different culture media and cell morphologies. Our results indicated that only the gene encoding for the ribosomal protein L6 showed a stable and constant expression. Furthermore, it displayed not transcriptional changes when S. schenckii infected larvae of Galleria mellonella or

  2. The TLR4 D299G and T399I SNPs are constitutively active to up-regulate expression of Trif-dependent genes.

    Directory of Open Access Journals (Sweden)

    Georgina L Hold

    Full Text Available Dysregulated Toll-Like Receptor (TLR signalling and genetic polymorphisms in these proteins are linked to many human diseases. We investigated TLR4 functional variants D299G and T399I to assess the impact on LPS-induced responsiveness in comparison to wild-type TLR4. The mechanism by which this occurs in unclear as these SNPs do not lie within the lipid A binding domain or dimerisation sites of the LPS-TLR4/MD2 receptor complexes. Transfection of TLR4D299G, TLR4T399I or TLR4D299G. T399I into HEK cells resulted in constitutive activation of an NF-κB reporter gene and a blunting of the LPS-induced reporter activation compared to WT-TLR4. Unstimulated human monocyte/macrophages, from patients with the D299G and T399I SNPs demonstrated a downregulation of many genes, particularly Tram/Trif signalling pathway constitutents compared to the TLR4 wild-type subjects supporting the concept of basal receptor activity. Monocyte/macrophages from carriers of the TLR4 D299G and T399I polymorphisms stimulated with LPS showed >6 fold lower levels of NF-κB and ∼12 fold higher IFN-β gene expression levels compared to wild-type subjects (P<0.05; MWU test and dramatically altered resultant cytokine profiles. We conclude that these TLR4 SNPs affect constitutive receptor activity which impacts on the hosts ability to respond to LPS challenge leading to a dysregulated sub-optimal immune response to infection.

  3. Partial rescue of postnatal growth plate abnormalities in Ihh mutants by expression of a constitutively active PTH/PTHrP receptor.

    Science.gov (United States)

    Maeda, Yukiko; Schipani, Ernestina; Densmore, Michael J; Lanske, Beate

    2010-02-01

    Indian hedgehog (Ihh) is essential for chondrocyte proliferation/differentiation and osteoblast differentiation during prenatal endochondral bone formation. Ihh expression in postnatal chondrocytes has a non-redundant role in maintaining a growth plate and sustaining trabecular bone after birth. Loss of Ihh in postnatal chondrocytes results in fusion of the growth plate and a decrease in trabecular bone. In order to normalize this abnormal chondrocyte phenotype and to investigate whether a putative rescue of the growth plate anomalies is sufficient to correct the severe alterations in the bone, we expressed a constitutively active PTH/PTHrP receptor (an Ihh downstream target) in the chondrocytes of Col2 alpha 1-Cre ER; Ihh(dld) mice by mating Col2 alpha 1-Cre ER; Ihh(fl/fl) mice with Col2 alpha 1-constitutively active PTH/PTHrP receptor transgenic mice (Jansen, J). Col2 alpha 1-Cre ER; Ihh(f/f); J mice were then injected with tamoxifen at P0 to generate Col2 alpha 1-Cre ER; Ihh(d/d); J mice. In contrast with the previously reported growth plate phenotype of Col2 alpha 1-Cre ER; Ihh(d/d) mice that displayed ectopic chondrocyte hypertrophy at P7, growth plates of Col2 alpha 1-Cre ER; Ihh(d/d); J double mutants were well organized, and exhibited a gene expression pattern similar to the one of control mice. However, expression of osteoblast markers and Dkk1, a Wnt signaling target, remains decreased in the bone collar of Col2 alpha 1-Cre ER; Ihh(d/d); J mice when compared to control mice despite the rescue of abnormal chondrocyte differentiation. Moreover, proliferation of chondrocytes was still significantly impaired in Col2 alpha 1-Cre ER; Ihh(d/d); J mice, and this eventually led to the fusion of the growth plate at P14. In summary, we have demonstrated that expression of a Jansen receptor in chondrocytes was able to rescue abnormal chondrocyte differentiation but not impaired chondrocyte proliferation and the bone anomalies in mice lacking the Ihh gene in

  4. WRKY2/34–VQ20 Modules in Arabidopsis thaliana Negatively Regulate Expression of a Trio of Related MYB Transcription Factors During Pollen Development

    Directory of Open Access Journals (Sweden)

    Rihua Lei

    2018-03-01

    Full Text Available Male gametogenesis in plants is tightly controlled and involves the complex and precise regulation of transcriptional reprogramming. Interactions between WRKY proteins and VQ motif-containing proteins are required to control these complicated transcriptional networks. However, our understanding of the mechanisms by which these complexes affect downstream gene expression is quite limited. In this study, we found that WRKY2 and WKRY34 repress MYB97, MYB101, and MYB120 expression during male gametogenesis. MYB expression was up-regulated in the wrky2-1 wrky34-1 vq20-1 triple mutant during male gametogenesis. The expression levels of six potential targets of the three MYBs increased the most in the wrky2-1 wrky34-1 vq20-1 triple mutant, followed by the wrky2-1 wrky34-1 double mutant, compared with in wild-type. Yeast one-hybrid and dual luciferase reporter assays indicated that WRKY2 and WRKY34 recognized the MYB97 promoter by binding to its W-boxes. MYB97 overexpression caused defects in pollen germination and pollen tube length, which impacted male fertility. Thus, WRKY2/34–VQ20 complexes appear to negatively regulate the expression of certain MYBs during plant male gametogenesis.

  5. Nictaba Homologs from Arabidopsis thaliana Are Involved in Plant Stress Responses

    Directory of Open Access Journals (Sweden)

    Lore Eggermont

    2018-01-01

    Full Text Available Plants are constantly exposed to a wide range of environmental stresses, but evolved complicated adaptive and defense mechanisms which allow them to survive in unfavorable conditions. These mechanisms protect and defend plants by using different immune receptors located either at the cell surface or in the cytoplasmic compartment. Lectins or carbohydrate-binding proteins are widespread in the plant kingdom and constitute an important part of these immune receptors. In the past years, lectin research has focused on the stress-inducible lectins. The Nicotiana tabacum agglutinin, abbreviated as Nictaba, served as a model for one family of stress-related lectins. Here we focus on three non-chimeric Nictaba homologs from Arabidopsis thaliana, referred to as AN3, AN4, and AN5. Confocal microscopy of ArathNictaba enhanced green fluorescent protein (EGFP fusion constructs transiently expressed in N. benthamiana or stably expressed in A. thaliana yielded fluorescence for AN4 and AN5 in the nucleus and the cytoplasm of the plant cell, while fluorescence for AN3 was only detected in the cytoplasm. RT-qPCR analysis revealed low expression for all three ArathNictabas in different tissues throughout plant development. Stress application altered the expression levels, but all three ArathNictabas showed a different expression pattern. Pseudomonas syringae infection experiments with AN4 and AN5 overexpression lines demonstrated a significantly higher tolerance of several transgenic lines to P. syringae compared to wild type plants. Finally, AN4 was shown to interact with two enzymes involved in plant defense, namely TGG1 and BGLU23. Taken together, our data suggest that the ArathNictabas represent stress-regulated proteins with a possible role in plant stress responses. On the long term this research can contribute to the development of more stress-resistant plants.

  6. Constitutively active RAS signaling reduces 1,25 dihydroxyvitamin D-mediated gene transcription in intestinal epithelial cells by reducing vitamin D receptor expression.

    Science.gov (United States)

    DeSmet, Marsha L; Fleet, James C

    2017-10-01

    High vitamin D status is associated with reduced colon cancer risk but these studies ignore the diversity in the molecular etiology of colon cancer. RAS activating mutations are common in colon cancer and they activate pro-proliferative signaling pathways. We examined the impact of RAS activating mutations on 1,25 dihydroxyvitamin D (1,25(OH) 2 D)-mediated gene expression in cultured colon and intestinal cell lines. Transient transfection of Caco-2 cells with a constitutively active mutant K-RAS (G12 V) significantly reduced 1,25(OH) 2 D-induced activity of both a human 25-hydroxyvitamin D, 24 hydroxyase (CYP24A1) promoter-luciferase and an artificial 3X vitamin D response element (VDRE) promoter-luciferase reporter gene. Young Adult Mouse Colon (YAMC) and Rat Intestinal Epithelial (RIE) cell lines with stable expression of mutant H-RAS had suppressed 1,25(OH) 2 D-mediated induction of CYP24A1 mRNA. The RAS effects were associated with lower Vitamin D receptor (VDR) mRNA and protein levels in YAMC and RIE cells and they could be partially reversed by VDR overexpression. RAS-mediated suppression of VDR levels was not due to either reduced VDR mRNA stability or increased VDR gene methylation. However, chromatin accessibility to the VDR gene at the proximal promoter (-300bp), an enhancer region at -6kb, and an enhancer region located in exon 3 was significantly reduced in RAS transformed YAMC cells (YAMC-RAS). These data show that constitutively active RAS signaling suppresses 1,25(OH) 2 D-mediated gene transcription in colon epithelial cells by reducing VDR gene transcription but the mechanism for this suppression is not yet known. These data suggest that cancers with RAS-activating mutations may be less responsive to vitamin D mediated treatment or chemoprevention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Metabolic changes in Arabidopsis thaliana plants overexpressing chalcone synthase

    NARCIS (Netherlands)

    Dao, Thi Thanh Hien

    2010-01-01

    The study has shown that it is possible to introduce the heterologous CHS gene in Arabidopsis thaliana and common multicopies of transgenes containing plants were obtained. Analysis of the change in metabolome of CHS transgenic plants, high expression transgenic lines can be identified by markers

  8. Nanoparticle-specific changes in Arabidopsis thaliana gene expression after exposure to ZnO, TiO2, and fullerene soot

    Czech Academy of Sciences Publication Activity Database

    Landa, Přemysl; Vaňková, Radomíra; Andrlová, Jana; Hodek, J.; Maršík, Petr; Štorchová, Helena; White, J. C.; Vaněk, Tomáš

    2012-01-01

    Roč. 241, Feb 2012 (2012), s. 55-62 ISSN 0304-3894 R&D Projects: GA MŠk(CZ) LH11047 Institutional research plan: CEZ:AV0Z50380511 Keywords : Microarray * Nanoparticles * Gene expression Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 3.925, year: 2012

  9. GEM2Net: from gene expression modeling to -omics networks, a new CATdb module to investigate Arabidopsis thaliana genes involved in stress response.

    Science.gov (United States)

    Zaag, Rim; Tamby, Jean Philippe; Guichard, Cécile; Tariq, Zakia; Rigaill, Guillem; Delannoy, Etienne; Renou, Jean-Pierre; Balzergue, Sandrine; Mary-Huard, Tristan; Aubourg, Sébastien; Martin-Magniette, Marie-Laure; Brunaud, Véronique

    2015-01-01

    CATdb (http://urgv.evry.inra.fr/CATdb) is a database providing a public access to a large collection of transcriptomic data, mainly for Arabidopsis but also for other plants. This resource has the rare advantage to contain several thousands of microarray experiments obtained with the same technical protocol and analyzed by the same statistical pipelines. In this paper, we present GEM2Net, a new module of CATdb that takes advantage of this homogeneous dataset to mine co-expression units and decipher Arabidopsis gene functions. GEM2Net explores 387 stress conditions organized into 18 biotic and abiotic stress categories. For each one, a model-based clustering is applied on expression differences to identify clusters of co-expressed genes. To characterize functions associated with these clusters, various resources are analyzed and integrated: Gene Ontology, subcellular localization of proteins, Hormone Families, Transcription Factor Families and a refined stress-related gene list associated to publications. Exploiting protein-protein interactions and transcription factors-targets interactions enables to display gene networks. GEM2Net presents the analysis of the 18 stress categories, in which 17,264 genes are involved and organized within 681 co-expression clusters. The meta-data analyses were stored and organized to compose a dynamic Web resource. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Arabidopsis thaliana peroxidase N

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ostergaard, L

    2000-01-01

    The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C...... (HRP C). HRP C is 54% identical to ATP N in sequence. When the structures of four class III plant peroxidases are superimposed, the regions with structural differences are non-randomly distributed; all are located in one half of the molecule. The architecture of the haem pocket of ATP N is very similar...... to that of HRP C, in agreement with the low small-molecule substrate specificity of all class III peroxidases. The structure of ATP N suggests that the pH dependence of the substrate turnover will differ from that of HRP C owing to differences in polarity of the residues in the substrate-access channel. Since...

  11. Listeria-vectored vaccine expressing the Mycobacterium tuberculosis 30 kDa major secretory protein via the constitutively active prfA* regulon boosts BCG efficacy against tuberculosis.

    Science.gov (United States)

    Jia, Qingmei; Dillon, Barbara Jane; Masleša-Galić, Saša; Horwitz, Marcus A

    2017-06-19

    A potent vaccine against tuberculosis, one of the world's deadliest diseases, is needed to enhance the immunity of people worldwide, most of whom have been vaccinated with the partially effective BCG vaccine. Here we investigate novel live attenuated recombinant Listeria monocytogenes (rLm) vaccines expressing the Mycobacterium tuberculosis (Mtb) 30 kDa major secretory protein (r30/Ag85B) (rLm30) as heterologous booster vaccines in animals primed with BCG. Using three attenuated Lm vectors, rLm Δ actA (LmI), rLm Δ actA Δ inlB (LmII), and rLm Δ actA Δ inlB prfA * (LmIII), we constructed five rLm30 vaccine candidates expressing the r30 linked in-frame to the Lm Listeriolycin O signal sequence and driven by the hly promoter (h30) or linked in-frame to the ActA N-terminus and driven by the actA promoter (a30). All five rLm30 vaccines secreted r30 in broth and macrophages; while rLm expressing r30 via a constitutively active prfA * regulon (rLmIII/a30) expressed the greatest amount of r30 in broth culture, all five rLm vaccines expressed equivalent amounts of r30 in infected macrophages. In comparative studies, boosting BCG-immunized mice with rLmIII/a30 induced the strongest antigen-specific T-cell responses, including splenic and lung polyfunctional CD4+ T-cells expressing the three cytokines of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-2 (IL-2) ( P vaccines were generally more potent booster vaccines than r30 in adjuvant and a recombinant adenovirus vaccine expressing r30. In a setting in which BCG alone was highly immunoprotective, boosting mice with rLmIII/a30, the most potent of the vaccines, significantly enhanced protection against aerosolized Mtb ( P <0.01). Copyright © 2017 American Society for Microbiology.

  12. An Epstein-Barr virus anti-apoptotic protein constitutively expressed in transformed cells and implicated in burkitt lymphomagenesis: the Wp/BHRF1 link.

    Directory of Open Access Journals (Sweden)

    Gemma L Kelly

    2009-03-01

    Full Text Available Two factors contribute to Burkitt lymphoma (BL pathogenesis, a chromosomal translocation leading to c-myc oncogene deregulation and infection with Epstein-Barr virus (EBV. Although the virus has B cell growth-transforming ability, this may not relate to its role in BL since many of the transforming proteins are not expressed in the tumor. Mounting evidence supports an alternative role, whereby EBV counteracts the high apoptotic sensitivity inherent to the c-myc-driven growth program. In that regard, a subset of BLs carry virus mutants in a novel form of latent infection that provides unusually strong resistance to apoptosis. Uniquely, these virus mutants use Wp (a viral promoter normally activated early in B cell transformation and express a broader-than-usual range of latent antigens. Here, using an inducible system to express the candidate antigens, we show that this marked apoptosis resistance is mediated not by one of the extended range of EBNAs seen in Wp-restricted latency but by Wp-driven expression of the viral bcl2 homologue, BHRF1, a protein usually associated with the virus lytic cycle. Interestingly, this Wp/BHRF1 connection is not confined to Wp-restricted BLs but appears integral to normal B cell transformation by EBV. We find that the BHRF1 gene expression recently reported in newly infected B cells is temporally linked to Wp activation and the presence of W/BHRF1-spliced transcripts. Furthermore, just as Wp activity is never completely eclipsed in in vitro-transformed lines, low-level BHRF1 transcripts remain detectable in these cells long-term. Most importantly, recognition by BHRF1-specific T cells confirms that such lines continue to express the protein independently of any lytic cycle entry. This work therefore provides the first evidence that BHRF1, the EBV bcl2 homologue, is constitutively expressed as a latent protein in growth-transformed cells in vitro and, in the context of Wp-restricted BL, may contribute to virus

  13. Inference of the Genetic Network Regulating Lateral Root Initiation in Arabidopsis thaliana

    KAUST Repository

    Muraro, D.; Voss, U.; Wilson, M.; Bennett, M.; Byrne, H.; De Smet, I.; Hodgman, C.; King, J.

    2013-01-01

    thaliana is stimulated by a cascade of regulators of which only the interactions of its initial elements have been identified. Using simulated gene expression data with known network topology, we compare the performance of inference algorithms, based

  14. Factors affecting UV-B-induced changes in Arabidopsis thaliana L. gene expression: The role of development, protective pigments and the chloroplast signal

    International Nuclear Information System (INIS)

    Jordan, B.R.; James, P.E.; Mackerness, S.A.H.

    1998-01-01

    Gene expression is known to change in response to UV-B radiation. In this paper, we have investigated three factors in Arabidopsis leaves that are likely to influence these changes: development, protective pigments and the 'chloroplast signal'. During late leaf development the major change in pigment composition, after exposure to UV-B radiation, is an increase in UV-absorbing pigments. Chl and Chl a/b ratio do not change substantially. Similarly Chl fluorescence is not altered. In contrast, RNA transcripts of photosynthetic proteins are reduced more in older leaves than in young leaves. To determine the role of flavonoids in UV-B protection, plants of Arabidopsis mutant tt-5, which have reduced flavonoids and sinapic esters, were exposed to UV-B and RNA transcript levels determined. The tt-mutants were more sensitive to UV-B radiation than wild-type. To examine the role of the chloroplast signal in regulating UV-B induced changes in gene expression, Arabidopsis gun mutants (genome uncoupled) have been used. The results show that UV-B-induced down-regulation still takes place in gun mutants and strongly suggests that the chloroplast signal is not required. Overall, this study clearly demonstrates that UV-B-induced changes in gene expression are influenced by both developmental and cellular factors but not chloroplastic factors

  15. Reduced expression of IL-12 p35 by SJL/J macrophages responding to Theiler's virus infection is associated with constitutive activation of IRF-3

    International Nuclear Information System (INIS)

    Dahlberg, Angela; Auble, Mark R.; Petro, Thomas M.

    2006-01-01

    Macrophages responding to viral infections may contribute to autoimmune demyelinating diseases (ADD). Macrophages from ADD-susceptible SJL/J mice responding to Theiler's Virus (TMEV) infection, the TLR7 agonist loxoribine, or the TLR4 agonist-LPS expressed less IL-12 p35 but more IL-12/23 p40 and IFN-β than macrophages from ADD-resistant B10.S mice. While expression of IRF-1 and -7 was similar between B10.S and SJL/J TMEV-infected macrophages, SJL/J but not B10.S macrophages exhibited constitutively active IRF-3. In contrast to overexpressed IRF-1, IRF-5, and IRF-7, which stimulated p35 promoter reporter activity, overexpressed IRF-3 repressed p35 promoter activity in response to TMEV infection, loxoribine, IFN-γ/LPS, but not IFN-γ alone. IRF-3 lessened but did not eliminate IRF-1-stimulated p35 promoter activity. Repression by IRF-3 required bp -172 to -122 of the p35 promoter. The data suggest that pre-activated IRF-3 is a major factor in the differences in IL-12 production between B10.S and SJL/J macrophages responding to TMEV

  16. Expression of an alfalfa (Medicago sativa L.) peroxidase gene in transgenic Arabidopsis thaliana enhances resistance to NaCl and H2O2.

    Science.gov (United States)

    Teng, K; Xiao, G Z; Guo, W E; Yuan, J B; Li, J; Chao, Y H; Han, L B

    2016-05-23

    Peroxidases (PODs) are enzymes that play important roles in catalyzing the reduction of H2O2 and the oxidation of various substrates. They function in many different and important biological processes, such as defense mechanisms, immune responses, and pathogeny. The POD genes have been cloned and identified in many plants, but their function in alfalfa (Medicago sativa L.) is not known, to date. Based on the POD gene sequence (GenBank accession No. L36157.1), we cloned the POD gene in alfalfa, which was named MsPOD. MsPOD expression increased with increasing H2O2. The gene was expressed in all of the tissues, including the roots, stems, leaves, and flowers, particularly in stems and leaves under light/dark conditions. A subcellular analysis showed that MsPOD was localized outside the cells. Transgenic Arabidopsis with MsPOD exhibited increased resistance to H2O2 and NaCl. Moreover, POD activity in the transgenic plants was significantly higher than that in wild-type Arabidopsis. These results show that MsPOD plays an important role in resistance to H2O2 and NaCl.

  17. Ectopic expression of GA 2-oxidase 6 from rapeseed (Brassica napus L.) causes dwarfism, late flowering and enhanced chlorophyll accumulation in Arabidopsis thaliana.

    Science.gov (United States)

    Yan, Jindong; Liao, Xiaoying; He, Reqing; Zhong, Ming; Feng, Panpan; Li, Xinmei; Tang, Dongying; Liu, Xuanming; Zhao, Xiaoying

    2017-02-01

    Gibberellins (GAs) are endogenous hormones that play an important role in higher plant growth and development. GA2-oxidase (GA2ox) promotes catabolism and inactivation of bioactive GAs or their precursors. In this study, we identified the GA2-oxidase gene, BnGA2ox6, and found it to be highly expressed in the silique and flower. Overexpression of BnGA2ox6 in Arabidopsis resulted in GA-deficiency symptoms, including inhibited elongation of the hypocotyl and stem, delayed seed germination, and late flowering. BnGA2ox6 overexpression reduced silique growth, but had no effect on seed development. Additionally, BnGA2ox6 overexpression enhanced chlorophyll b and total chlorophyll accumulation, and downregulated mRNA expression levels of the CHL1 and RCCR genes, which are involved in the chlorophyll degradation. These findings suggest that BnGA2ox6 regulates plant hight, silique development, flowering and chlorophyll accumulation in transgenic Arabidopsis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Threshold-dependent repression of SPL gene expression by miR156/miR157 controls vegetative phase change in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Jia He

    2018-04-01

    Full Text Available Vegetative phase change is regulated by a decrease in the abundance of the miRNAs, miR156 and miR157, and the resulting increase in the expression of their targets, SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL transcription factors. To determine how miR156/miR157 specify the quantitative and qualitative changes in leaf morphology that occur during vegetative phase change, we measured their abundance in successive leaves and characterized the phenotype of mutations in different MIR156 and MIR157 genes. miR156/miR157 decline rapidly between leaf 1&2 and leaf 3 and decrease more slowly after this point. The amount of miR156/miR157 in leaves 1&2 greatly exceeds the threshold required to specify their identity. Subsequent leaves have relatively low levels of miR156/miR157 and are sensitive to small changes in their abundance. In these later-formed leaves, the amount of miR156/miR157 is close to the threshold required to specify juvenile vs. adult identity; a relatively small decrease in the abundance of miR156/157 in these leaves produces a disproportionately large increase in SPL proteins and a significant change in leaf morphology. miR157 is more abundant than miR156 but has a smaller effect on shoot morphology and SPL gene expression than miR156. This may be attributable to the inefficiency with which miR157 is loaded onto AGO1, as well as to the presence of an extra nucleotide at the 5' end of miR157 that is mis-paired in the miR157:SPL13 duplex. miR156 represses different targets by different mechanisms: it regulates SPL9 by a combination of transcript cleavage and translational repression and regulates SPL13 primarily by translational repression. Our results offer a molecular explanation for the changes in leaf morphology that occur during shoot development in Arabidopsis and provide new insights into the mechanism by which miR156 and miR157 regulate gene expression.

  19. Activation of the Constitutive Androstane Receptor induces hepatic lipogenesis and regulates Pnpla3 gene expression in a LXR-independent way

    Energy Technology Data Exchange (ETDEWEB)

    Marmugi, Alice; Lukowicz, Céline; Lasserre, Frederic; Montagner, Alexandra; Polizzi, Arnaud; Ducheix, Simon; Goron, Adeline; Gamet-Payrastre, Laurence [INRA, TOXALIM (Research Centre in Food Toxicology), Toulouse (France); Université de Toulouse, INP, UPS, TOXALIM, Toulouse (France); Gerbal-Chaloin, Sabine [Institute of Regenerative Medicine and Biotherapy, INSERM, U1183 Montpellier (France); Pascussi, Jean Marc [Centre National de la Recherche Scientifique, UMR5203, Institut de Génomique Fonctionnelle, Montpellier (France); Moldes, Marthe [Centre de Recherche Saint-Antoine, INSERM, UMR 938, Sorbonne Universités, Université Paris 6, Paris (France); Institut Hospitalo-Universitaire ICAN, Paris (France); Pineau, Thierry; Guillou, Hervé [INRA, TOXALIM (Research Centre in Food Toxicology), Toulouse (France); Université de Toulouse, INP, UPS, TOXALIM, Toulouse (France); Mselli-Lakhal, Laila, E-mail: laila.lakhal@toulouse.inra.fr [INRA, TOXALIM (Research Centre in Food Toxicology), Toulouse (France); Université de Toulouse, INP, UPS, TOXALIM, Toulouse (France)

    2016-07-15

    The Constitutive Androstane Receptor (CAR, NR1I3) has been newly described as a regulator of energy metabolism. A relevant number of studies using animal models of obesity suggest that CAR activation could be beneficial on the metabolic balance. However, this remains controversial and the underlying mechanisms are still unknown. This work aimed to investigate the effect of CAR activation on hepatic energy metabolism during physiological conditions, i.e. in mouse models not subjected to metabolic/nutritional stress. Gene expression profiling in the liver of CAR knockout and control mice on chow diet and treated with a CAR agonist highlighted CAR-mediated up-regulations of lipogenic genes, concomitant with neutral lipid accumulation. A strong CAR-mediated up-regulation of the patatin-like phospholipase domain-containing protein 3 (Pnpla3) was demonstrated. Pnpla3 is a gene whose polymorphism is associated with the pathogenesis of nonalcoholic fatty liver disease (NAFLD) development. This observation was confirmed in human hepatocytes treated with the antiepileptic drug and CAR activator, phenobarbital and in immortalized human hepatocytes treated with CITCO. Studying the molecular mechanisms controlling Pnpla3 gene expression, we demonstrated that CAR does not act by a direct regulation of Pnpla3 transcription or via the Liver X Receptor but may rather involve the transcription factor Carbohydrate Responsive Element-binding protein. These data provide new insights into the regulation by CAR of glycolytic and lipogenic genes and on pathogenesis of steatosis. This also raises the question concerning the impact of drugs and environmental contaminants in lipid-associated metabolic diseases. - Highlights: • Induction of hepatic glycolytic and lipogenic genes upon CAR activation by TCPOBOP. • These effects are not mediated by the nuclear receptor LXR. • CAR activation resulted in hepatic lipid accumulation. • Pnpla3 expression is regulated by CAR in mouse liver and

  20. Activation of the Constitutive Androstane Receptor induces hepatic lipogenesis and regulates Pnpla3 gene expression in a LXR-independent way

    International Nuclear Information System (INIS)

    Marmugi, Alice; Lukowicz, Céline; Lasserre, Frederic; Montagner, Alexandra; Polizzi, Arnaud; Ducheix, Simon; Goron, Adeline; Gamet-Payrastre, Laurence; Gerbal-Chaloin, Sabine; Pascussi, Jean Marc; Moldes, Marthe; Pineau, Thierry; Guillou, Hervé; Mselli-Lakhal, Laila

    2016-01-01

    The Constitutive Androstane Receptor (CAR, NR1I3) has been newly described as a regulator of energy metabolism. A relevant number of studies using animal models of obesity suggest that CAR activation could be beneficial on the metabolic balance. However, this remains controversial and the underlying mechanisms are still unknown. This work aimed to investigate the effect of CAR activation on hepatic energy metabolism during physiological conditions, i.e. in mouse models not subjected to metabolic/nutritional stress. Gene expression profiling in the liver of CAR knockout and control mice on chow diet and treated with a CAR agonist highlighted CAR-mediated up-regulations of lipogenic genes, concomitant with neutral lipid accumulation. A strong CAR-mediated up-regulation of the patatin-like phospholipase domain-containing protein 3 (Pnpla3) was demonstrated. Pnpla3 is a gene whose polymorphism is associated with the pathogenesis of nonalcoholic fatty liver disease (NAFLD) development. This observation was confirmed in human hepatocytes treated with the antiepileptic drug and CAR activator, phenobarbital and in immortalized human hepatocytes treated with CITCO. Studying the molecular mechanisms controlling Pnpla3 gene expression, we demonstrated that CAR does not act by a direct regulation of Pnpla3 transcription or via the Liver X Receptor but may rather involve the transcription factor Carbohydrate Responsive Element-binding protein. These data provide new insights into the regulation by CAR of glycolytic and lipogenic genes and on pathogenesis of steatosis. This also raises the question concerning the impact of drugs and environmental contaminants in lipid-associated metabolic diseases. - Highlights: • Induction of hepatic glycolytic and lipogenic genes upon CAR activation by TCPOBOP. • These effects are not mediated by the nuclear receptor LXR. • CAR activation resulted in hepatic lipid accumulation. • Pnpla3 expression is regulated by CAR in mouse liver and

  1. A constitutively expressed pair of rpoE2-chrR2 in Azospirillum brasilense Sp7 is required for survival under antibiotic and oxidative stress.

    Science.gov (United States)

    Gupta, Namrata; Kumar, Santosh; Mishra, Mukti Nath; Tripathi, Anil Kumar

    2013-02-01

    Extracytoplasmic function (ECF) sigma factors (σ(E)) are known to bring about changes in gene expression to enable bacteria to adapt to different stresses. The Azospirillum brasilense Sp245 genome harbours nine genes encoding σ(E), of which two are adjacent to the genes encoding ChrR-type zinc-binding anti-sigma (ZAS) factors. We describe here the role and regulation of a new pair of rpoE-chrR, which was found in the genome of A. brasilense Sp7 in addition to the previously described rpoE-chrR pair (designated rpoE1-chrR1). The rpoE2-chrR2 pair is also cotranscribed, and their products show protein-protein interaction. The -10 and -35 promoter elements of rpoE2-chrR2 and rpoE1-chrR1 were similar but not identical. Unlike the promoter of rpoE1-chrR1, the rpoE2-chrR2 promoter was neither autoregulated nor induced by oxidative stress. Inactivation of chrR2 or overexpression of rpoE2 in A. brasilense Sp7 resulted in an overproduction of carotenoids. It also conferred resistance to oxidative stresses and antibiotics. By controlling the synthesis of carotenoids, initiation and elongation of translation, protein folding and purine biosynthesis, RpoE2 seems to play a crucial role in preventing and repairing the cellular damage caused by oxidative stress. Lack of autoregulation and constitutive expression of rpoE2-chrR2 suggest that RpoE2-ChrR2 may provide a rapid mechanism to cope with oxidative stress, wherein singlet oxygen ((1)O(2))-mediated dissociation of the RpoE2-ChrR2 complex might release RpoE2 to drive the expression of its target genes.

  2. Overexpression of SAMDC1 gene in Arabidopsis thaliana increases expression of defense-related genes as well as resistance to Pseudomonas syringae and Hyaloperonospora arabidopsidis

    Directory of Open Access Journals (Sweden)

    Francisco eMarco

    2014-03-01

    Full Text Available It has been previously described that elevation of endogenous spermine levels in Arabidopsis could be achieved by transgenic overexpression of S-Adenosylmethionine decarboxylase (SAMDC or Spermine synthase (SPMS. In both cases, spermine accumulation had an impact on the plant transcriptome, with up-regulation of a set of genes enriched in functional categories involved in defense-related processes against both biotic and abiotic stresses. In this work, the response of SAMDC1-overexpressing plants against bacterial and oomycete pathogens has been tested. The expression of several pathogen defense-related genes was induced in these plants as well as in wild type plants exposed to an exogenous supply of spermine. SAMDC1-overexpressing plants showed an increased tolerance to infection by Pseudomonas syringae and by Hyaloperonospora arabidopsidis. Both results add more evidence to the hypothesis that spermine plays a key role in plant resistance to biotic stress.

  3. AtRTD2: A Reference Transcript Dataset for accurate quantification of alternative splicing and expression changes in Arabidopsis thaliana RNA-seq data

    KAUST Repository

    Zhang, Runxuan

    2016-05-06

    Background Alternative splicing is the major post-transcriptional mechanism by which gene expression is regulated and affects a wide range of processes and responses in most eukaryotic organisms. RNA-sequencing (RNA-seq) can generate genome-wide quantification of individual transcript isoforms to identify changes in expression and alternative splicing. RNA-seq is an essential modern tool but its ability to accurately quantify transcript isoforms depends on the diversity, completeness and quality of the transcript information. Results We have developed a new Reference Transcript Dataset for Arabidopsis (AtRTD2) for RNA-seq analysis containing over 82k non-redundant transcripts, whereby 74,194 transcripts originate from 27,667 protein-coding genes. A total of 13,524 protein-coding genes have at least one alternatively spliced transcript in AtRTD2 such that about 60% of the 22,453 protein-coding, intron-containing genes in Arabidopsis undergo alternative splicing. More than 600 putative U12 introns were identified in more than 2,000 transcripts. AtRTD2 was generated from transcript assemblies of ca. 8.5 billion pairs of reads from 285 RNA-seq data sets obtained from 129 RNA-seq libraries and merged along with the previous version, AtRTD, and Araport11 transcript assemblies. AtRTD2 increases the diversity of transcripts and through application of stringent filters represents the most extensive and accurate transcript collection for Arabidopsis to date. We have demonstrated a generally good correlation of alternative splicing ratios from RNA-seq data analysed by Salmon and experimental data from high resolution RT-PCR. However, we have observed inaccurate quantification of transcript isoforms for genes with multiple transcripts which have variation in the lengths of their UTRs. This variation is not effectively corrected in RNA-seq analysis programmes and will therefore impact RNA-seq analyses generally. To address this, we have tested different genome

  4. Gene Expression, Protein Function and Pathways of Arabidopsis thaliana Responding to Silver Nanoparticles in Comparison to Silver Ions, Cold, Salt, Drought, and Heat

    Directory of Open Access Journals (Sweden)

    Eisa Kohan-Baghkheirati

    2015-03-01

    Full Text Available Silver nanoparticles (AgNPs have been widely used in industry due to their unique physical and chemical properties. However, AgNPs have caused environmental concerns. To understand the risks of AgNPs, Arabidopsis microarray data for AgNP, Ag+, cold, salt, heat and drought stresses were analyzed. Up- and down-regulated genes of more than two-fold expression change were compared, while the encoded proteins of shared and unique genes between stresses were subjected to differential enrichment analyses. AgNPs affected the fewest genes (575 in the Arabidopsis genome, followed by Ag+ (1010, heat (1374, drought (1435, salt (4133 and cold (6536. More genes were up-regulated than down-regulated in AgNPs and Ag+ (438 and 780, respectively while cold down-regulated the most genes (4022. Responses to AgNPs were more similar to those of Ag+ (464 shared genes, cold (202, and salt (163 than to drought (50 or heat (30; the genes in the first four stresses were enriched with 32 PFAM domains and 44 InterPro protein classes. Moreover, 111 genes were unique in AgNPs and they were enriched in three biological functions: response to fungal infection, anion transport, and cell wall/plasma membrane related. Despite shared similarity to Ag+, cold and salt stresses, AgNPs are a new stressor to Arabidopsis.

  5. Expression, crystallization and preliminary X-ray diffraction analysis of the CMM2 region of the Arabidopsis thaliana Morpheus' molecule 1 protein.

    Science.gov (United States)

    Petty, Tom J; Nishimura, Taisuke; Emamzadah, Soheila; Gabus, Caroline; Paszkowski, Jerzy; Halazonetis, Thanos D; Thore, Stéphane

    2010-08-01

    Of the known epigenetic control regulators found in plants, the Morpheus' molecule 1 (MOM1) protein is atypical in that the deletion of MOM1 does not affect the level of epigenetic marks controlling the transcriptional status of the genome. A short 197-amino-acid fragment of the MOM1 protein sequence can complement MOM1 deletion when coupled to a nuclear localization signal, suggesting that this region contains a functional domain that compensates for the loss of the full-length protein. Numerous constructs centred on the highly conserved MOM1 motif 2 (CMM2) present in these 197 residues have been generated and expressed in Escherichia coli. Following purification and crystallization screening, diamond-shaped single crystals were obtained that diffracted to approximately 3.2 A resolution. They belonged to the trigonal space group P3(1)21 (or P3(2)21), with unit-cell parameters a=85.64, c=292.74 A. Structure determination is ongoing.

  6. Expression, crystallization and preliminary X-ray diffraction analysis of the CMM2 region of the Arabidopsis thaliana Morpheus’ molecule 1 protein

    Science.gov (United States)

    Petty, Tom J.; Nishimura, Taisuke; Emamzadah, Soheila; Gabus, Caroline; Paszkowski, Jerzy; Halazonetis, Thanos D.; Thore, Stéphane

    2010-01-01

    Of the known epigenetic control regulators found in plants, the Morpheus’ molecule 1 (MOM1) protein is atypical in that the deletion of MOM1 does not affect the level of epigenetic marks controlling the transcriptional status of the genome. A short 197-amino-acid fragment of the MOM1 protein sequence can complement MOM1 deletion when coupled to a nuclear localization signal, suggesting that this region contains a functional domain that compensates for the loss of the full-length protein. Numerous constructs centred on the highly conserved MOM1 motif 2 (CMM2) present in these 197 residues have been generated and expressed in Escherichia coli. Following purification and crystallization screening, diamond-shaped single crystals were obtained that diffracted to ∼3.2 Å resolution. They belonged to the trigonal space group P3121 (or P3221), with unit-cell parameters a = 85.64, c = 292.74 Å. Structure determination is ongoing. PMID:20693667

  7. Construction and characterization of stable, constitutively expressed, chromosomal green and red fluorescent transcriptional fusions in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei.

    Science.gov (United States)

    Su, Shengchang; Bangar, Hansraj; Saldanha, Roland; Pemberton, Adin; Aronow, Bruce; Dean, Gary E; Lamkin, Thomas J; Hassett, Daniel J

    2014-10-01

    Here, we constructed stable, chromosomal, constitutively expressed, green and red fluorescent protein (GFP and RFP) as reporters in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei. Using bioinformatic approaches and other experimental analyses, we identified P0253 and P1 as potent promoters that drive the optimal expression of fluorescent reporters in single copy in B. anthracis and Burkholderia spp. as well as their surrogate strains, respectively. In comparison, Y. pestis and its surrogate strain need two chromosomal copies of cysZK promoter (P2cysZK) for optimal fluorescence. The P0253-, P2cysZK-, and P1-driven GFP and RFP fusions were first cloned into the vectors pRP1028, pUC18R6KT-mini-Tn7T-Km, pmini-Tn7-gat, or their derivatives. The resultant constructs were delivered into the respective surrogates and subsequently into the select agent strains. The chromosomal GFP- and RFP-tagged strains exhibited bright fluorescence at an exposure time of less than 200 msec and displayed the same virulence traits as their wild-type parental strains. The utility of the tagged strains was proven by the macrophage infection assays and lactate dehydrogenase release analysis. Such strains will be extremely useful in high-throughput screens for novel compounds that could either kill these organisms, or interfere with critical virulence processes in these important bioweapon agents and during infection of alveolar macrophages. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  8. Altered methylation and expression of ER-associated degradation factors in long-term alcohol and constitutive ER stress-induced murine hepatic tumors

    Directory of Open Access Journals (Sweden)

    Hui eHan

    2013-10-01

    Full Text Available Mortality from liver cancer in humans is increasingly attributable to heavy or long-term alcohol consumption. The mechanisms by which alcohol exerts its carcinogenic effect are not well understood. In this study, the role of alcohol-induced endoplasmic reticulum (ER stress response in liver cancer development was investigated using an animal model with a liver knockout of the chaperone BiP and under constitutive hepatic ER stress. Long-term alcohol and high fat diet (HFD feeding resulted in higher levels of serum alanine aminotransferase (ALT, impaired ER stress response, and higher incidence of liver tumor in older (aged 16 months knockout females than in either middle-aged (6 months knockouts or older (aged 16 months wild type females. In the older knockout females, stronger effects of the alcohol on methylation of CpG islands at promoter regions of genes involved in the ER associated degradation (ERAD were also detected. Altered expression of ERAD factors including derlin 3, Creld2 (cysteine-rich with EGF-like domains 2, Herpud1 (ubiquitin-like domain member, Wfs1 (wolfram syndrome gene, and Yod1 (deubiquinating enzyme 1 was co-present with decreased proteasome activities, increased estrogen receptor alpha variant (ERa36, and enhanced phosphorylations of ERK1/2 (extracellular signal-regulated protein kinases 1 and 2 and STAT3 (the signal transducers and activators of transcription in the older knockout female fed alcohol. Our results suggest that long-term alcohol consumption and ageing may promote liver tumorigenesis in females through interfering with DNA methylation and expression of genes involved in the ER associated degradation.

  9. Improved stress tolerance and productivity in transgenic rice plants constitutively expressing the Oryza sativa glutathione synthetase OsGS under paddy field conditions.

    Science.gov (United States)

    Park, Seong-Im; Kim, Young-Saeng; Kim, Jin-Ju; Mok, Ji-Eun; Kim, Yul-Ho; Park, Hyang-Mi; Kim, Il-Sup; Yoon, Ho-Sung

    2017-08-01

    Reactive oxygen species, which increase under various environmental stresses, have deleterious effects on plants. An important antioxidant, glutathione, is used to detoxify reactive oxygen species in plant cells and is mainly produced by two enzymes: gamma-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase (GS). To evaluate the functional roles of the glutathione synthetase gene (OsGS) in rice, we generated four independent transgenic rice plants (TG1-TG4) that overexpressed OsGS under the control of the constitutively expressed OsCc1 promoter. When grown under natural paddy field conditions, the TG rice plants exhibited greater growth development, higher chlorophyll content, and higher GSH/GSSH ratios than control wild-type (WT) rice plants. Subsequently, the TG rice plants enhanced redox homeostasis by preventing hydroperoxide-mediated membrane damage, which improved their adaptation to environmental stresses. As a result, TG rice plants improved rice grain yield and total biomass following increases in panicle number and number of spikelets per panicle, despite differences in climate during the cultivation periods of 2014 and 2015. Overall, our results indicate that OsGS overexpression improved redox homeostasis by enhancing the glutathione pool, which resulted in greater tolerance to environmental stresses in the paddy fields. Copyright © 2017. Published by Elsevier GmbH.

  10. Wound-induced expression of DEFECTIVE IN ANTHER DEHISCENCE1 and DAD1-like lipase genes is mediated by both CORONATINE INSENSITIVE1-dependent and independent pathways in Arabidopsis thaliana.

    Science.gov (United States)

    Ruduś, Izabela; Terai, Haruka; Shimizu, Takafumi; Kojima, Hisae; Hattori, Kazuki; Nishimori, Yuka; Tsukagoshi, Hironaka; Kamiya, Yuji; Seo, Mitsunori; Nakamura, Kenzo; Kępczyński, Jan; Ishiguro, Sumie

    2014-06-01

    Endogenous JA production is not necessary for wound-induced expression of JA-biosynthetic lipase genes such as DAD1 in Arabidopsis. However, the JA-Ile receptor COI1 is often required for their JA-independent induction. Wounding is a serious event in plants that may result from insect feeding and increase the risk of pathogen infection. Wounded plants produce high amounts of jasmonic acid (JA), which triggers the expression of insect and pathogen resistance genes. We focused on the transcriptional regulation of DEFECTIVE IN ANTHER DEHISCENCE1 and six of its homologs including DONGLE (DGL) in Arabidopsis, which encode lipases involved in JA biosynthesis. Plants constitutively expressing DAD1 accumulated a higher amount of JA than control plants after wounding, indicating that the expression of these lipase genes contributes to determining JA levels. We found that the expression of DAD1, DGL, and other DAD1-LIKE LIPASE (DALL) genes is induced upon wounding. Some DALLs were also expressed in unwounded leaves. Further experiments using JA-biosynthetic and JA-response mutants revealed that the wound induction of these genes is regulated by several distinct pathways. DAD1 and most of its homologs other than DALL4 were fully induced without relying on endogenous JA-Ile production and were only partly affected by JA deficiency, indicating that positive feedback by JA is not necessary for induction of these genes. However, DAD1 and DGL required CORONATINE INSENSITIVE1 (COI1) for their expression, suggesting that a molecule other than JA might act as a regulator of COI1. Wound induction of DALL1, DALL2, and DALL3 did not require COI1. This differential regulation of DAD1 and its homologs might explain their functions at different time points after wounding.

  11. An OMV Vaccine Derived from a Capsular Group B Meningococcus with Constitutive FetA Expression: Preclinical Evaluation of Immunogenicity and Toxicity.

    Directory of Open Access Journals (Sweden)

    Gunnstein Norheim

    Full Text Available Following the introduction of effective protein-polysaccharide conjugate vaccines against capsular group C meningococcal disease in Europe, meningococci of capsular group B remain a major cause of death and can result in debilitating sequelae. The outer membrane proteins PorA and FetA have previously been shown to induce bactericidal antibodies in humans. Despite considerable antigenic variation among PorA and FetA OMPs in meningococci, systematic molecular epidemiological studies revealed this variation is highly structured so that a limited repertoire of antigenic types is congruent with the hyperinvasive meningococcal lineages that have caused most of the meningococcal disease in Europe in recent decades. Here we describe the development of a prototype vaccine against capsular group B meningococcal infection based on a N. meningitidis isolate genetically engineered to have constitutive expression of the outer membrane protein FetA. Deoxycholate outer membrane vesicles (dOMVs extracted from cells cultivated in modified Frantz medium contained 21.8% PorA protein, 7.7% FetA protein and 0.03 μg LPS per μg protein (3%. The antibody response to the vaccine was tested in three mouse strains and the toxicological profile of the vaccine was tested in New Zealand white rabbits. Administration of the vaccine, MenPF-1, when given by intramuscular injection on 4 occasions over a 9 week period, was well tolerated in rabbits up to 50 μg/dose, with no evidence of systemic toxicity. These data indicated that the MenPF-1 vaccine had a toxicological profile suitable for testing in a phase I clinical trial.

  12. Constitutive Activation of the G-Protein Subunit G[alpha]s within Forebrain Neurons Causes PKA-Dependent Alterations in Fear Conditioning and Cortical "Arc" mRNA Expression

    Science.gov (United States)

    Kelly, Michele P.; Cheung, York-Fong; Favilla, Christopher; Siegel, Steven J.; Kanes, Stephen J.; Houslay, Miles D.; Abel, Ted

    2008-01-01

    Memory formation requires cAMP signaling; thus, this cascade has been of great interest in the search for cognitive enhancers. Given that medications are administered long-term, we determined the effects of chronically increasing cAMP synthesis in the brain by expressing a constitutively active isoform of the G-protein subunit G[alpha]s…

  13. The genome of Arabidopsis thaliana.

    OpenAIRE

    Goodman, H M; Ecker, J R; Dean, C

    1995-01-01

    Arabidopsis thaliana is a small flowering plant that is a member of the family cruciferae. It has many characteristics--diploid genetics, rapid growth cycle, relatively low repetitive DNA content, and small genome size--that recommend it as the model for a plant genome project. The current status of the genetic and physical maps, as well as efforts to sequence the genome, are presented. Examples are given of genes isolated by using map-based cloning. The importance of the Arabidopsis project ...

  14. Multiple reference genomes and transcriptomes for Arabidopsis thaliana

    KAUST Repository

    Gan, Xiangchao

    2011-08-28

    Genetic differences between Arabidopsis thaliana accessions underlie the plants extensive phenotypic variation, and until now these have been interpreted largely in the context of the annotated reference accession Col-0. Here we report the sequencing, assembly and annotation of the genomes of 18 natural A. thaliana accessions, and their transcriptomes. When assessed on the basis of the reference annotation, one-third of protein-coding genes are predicted to be disrupted in at least one accession. However, re-annotation of each genome revealed that alternative gene models often restore coding potential. Gene expression in seedlings differed for nearly half of expressed genes and was frequently associated with cis variants within 5 kilobases, as were intron retention alternative splicing events. Sequence and expression variation is most pronounced in genes that respond to the biotic environment. Our data further promote evolutionary and functional studies in A. thaliana, especially the MAGIC genetic reference population descended from these accessions. ©2011 Macmillan Publishers Limited. All rights reserved.

  15. Multiple reference genomes and transcriptomes for Arabidopsis thaliana

    KAUST Repository

    Gan, Xiangchao; Stegle, Oliver; Behr, Jonas; Steffen, Joshua G.; Drewe, Philipp; Hildebrand, Katie L.; Lyngsoe, Rune; Schultheiss, Sebastian J.; Osborne, Edward J.; Sreedharan, Vipin T.; Kahles, André ; Bohnert, Regina; Jean, Gé raldine; Derwent, Paul; Kersey, Paul; Belfield, Eric J.; Harberd, Nicholas P.; Kemen, Eric; Toomajian, Christopher; Kover, Paula X.; Clark, Richard M.; Rä tsch, Gunnar; Mott, Richard

    2011-01-01

    Genetic differences between Arabidopsis thaliana accessions underlie the plants extensive phenotypic variation, and until now these have been interpreted largely in the context of the annotated reference accession Col-0. Here we report the sequencing, assembly and annotation of the genomes of 18 natural A. thaliana accessions, and their transcriptomes. When assessed on the basis of the reference annotation, one-third of protein-coding genes are predicted to be disrupted in at least one accession. However, re-annotation of each genome revealed that alternative gene models often restore coding potential. Gene expression in seedlings differed for nearly half of expressed genes and was frequently associated with cis variants within 5 kilobases, as were intron retention alternative splicing events. Sequence and expression variation is most pronounced in genes that respond to the biotic environment. Our data further promote evolutionary and functional studies in A. thaliana, especially the MAGIC genetic reference population descended from these accessions. ©2011 Macmillan Publishers Limited. All rights reserved.

  16. Low Constitutive Cell Surface Expression of HLA-B Is Caused by a Posttranslational Mechanism Involving Glu180 and Arg239

    DEFF Research Database (Denmark)

    Dellgren, Christoffer; Ekwelum, Vanessa A. C.; Ormhøj, Maria

    2016-01-01

    HLA class I cell surface expression is crucial for normal immune responses, and variability in HLA expression may influence the course of infections. We have previously shown that classical HLA class I expression on many human cell types is biased with greatly reduced expression of HLA-B compared...... by affecting HLA processing in the Ag presentation pathway....

  17. The fate of retrotransposed processed genes in Arabidopsis thaliana.

    Science.gov (United States)

    Abdelkarim, Basma T M; Maranda, Vincent; Drouin, Guy

    2017-04-20

    Processed genes are functional genes that have arisen as a result of the retrotransposition of mRNA molecules. We found 6 genes that generated processed genes in the common ancestor of five Brassicaceae species (Arabidopsis thaliana, Arabidopsis lyrata, Capsella rubella, Brassica rapa and Thellungiella parvula). These processed genes have therefore been kept for at least 30millionyears. Analyses of the Ka/Ks ratio of these genes, and of those having given rise to them, show that they evolve relatively slowly and suggest that the processed genes maintained the same function as that of their parental gene. There is a significant negative correlation between the number of ESTs and transcripts produced and the Ka/Ks ratios of the parental genes but not of the processed genes. This suggests that selection has not yet adapted the selective pressure the processed genes experience to their expression level. However, the A. thaliana processed genes tend to be expressed in the same tissues as that of their parental genes. Furthermore, most have a CAATT-box, a TATA-box and are located about 1kb from another protein-coding gene. Altogether, our results suggest that the processed genes found in the A. thaliana genome have been kept to produce more of the same product, and in the same tissues, as that encoded by their parental gene. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  18. Effect of inducers and culturing processes on laccase synthesis in Phanerochaete chrysosporium NCIM 1197 and the constitutive expression of laccase isozymes

    DEFF Research Database (Denmark)

    Manavalan, Arulmani

    2006-01-01

    Phanerochaete chrysosporium NCIM 1197 constitutively secretes considerable level of extracellular enzyme laccase in defined growth medium. Effect of several inducers on laccase production was attempted and found that copper sulphate alone at 30 mM concentration accelerate the laccase production...

  19. The Constitutional Amendment Process

    Science.gov (United States)

    Chism, Kahlil

    2005-01-01

    This article discusses the constitutional amendment process. Although the process is not described in great detail, Article V of the United States Constitution allows for and provides instruction on amending the Constitution. While the amendment process currently consists of six steps, the Constitution is nevertheless quite difficult to change.…

  20. Constitutional Rights in Indonesia

    OpenAIRE

    Judhariksawan

    2018-01-01

    The constitution is fundamental to the life of the modern state as a major foothold in state governance. Includes the guarantee of constitutional rights of citizens. The The constitution is the basis of state organizers to be implemented so that the state is obliged to guarantee the fulfillment of citizens' constitutional rights. Human rights have become an important part of the modern constitution. This study will describe how human rights guarantees become part of consti...

  1. Establishment of an Indirect Genetic Transformation Method for Arabidopsis thaliana ecotype Bangladesh

    Directory of Open Access Journals (Sweden)

    Bulbul AHMED

    2011-11-01

    Full Text Available Arabidopsis thaliana is a small flowering plant belonging to the Brassicaceae family, which is adopted as a model plant for genetic research. Agrobacterium tumifaciensmediated transformation method for A. thaliana ecotype Bangladesh was established. Leaf discs of A. thaliana were incubated with A. tumefaciens strain LBA4404 containing chimeric nos. nptII. nos and intron-GUS genes. Following inoculation and co-cultivation, leaf discs were cultured on selection medium containing 50 mg/l kanamycin + 50 mg/l cefotaxime + 1.5 mg/l NAA and kanamycin resistant shoots were induced from the leaf discs after two weeks. Shoot regeneration was achieved after transferring the tissues onto fresh medium of the same combination. Finally, the shoots were rooted on MS medium containing 50 mg/l kanamycin. Incorporation and expression of the transgenes were confirmed by PCR analysis. Using this protocol, transgenic A. thaliana plants can be obtained and indicates that genomic transformation in higher plants is possible through insertion of desired gene. Although Agrobacterium mediated genetic transformation is established for A. thaliana, this study was the conducted to transform A. thaliana ecotype Bangladesh.

  2. Constitutional changes and the dilemmas of constitutionalism

    Directory of Open Access Journals (Sweden)

    Arsen Bačić

    2009-01-01

    Full Text Available The need to develop constitutional mechanisms whose aim is to resolve fundamental relations in society demands the widest possible inclusion of all of society’s active participants in the discussion on the need to adopt or revise the Constitution. The opening of every new round of constitutional changes is of great importance because it always unlocks certain new and important questions. The answers to those questions should be offered by state authority (policy and civil society including science and its disciplines. In this paper, the author mentions several topics which are of interest in the current discussion on the significance of current constitutional changes for the future of the development of constitutionalism and democracy in the Republic of Croatia. These are above all topics of political and legal constitutionalism and suggestions linked to strengthening the independence of judicial powers. The author advocates consistent application of constitutional control and check mechanisms which exclude all insularity of judicial powers in relation to democratic control.

  3. Phytoremediation of the organic Xenobiotic simazine by p450-1a2 transgenic Arabidopsis thaliana plants.

    Science.gov (United States)

    Azab, Ehab; Hegazy, Ahmad K; El-Sharnouby, Mohamed E; Abd Elsalam, Hassan E

    2016-01-01

    The potential use of human P450-transgenic plants for phytoremediation of pesticide contaminated soils was tested in laboratory and greenhouse experiments. The transgenic P450 CYP1A2 gene Arabidopsis thaliana plants metabolize number of herbicides, insecticides and industrial chemicals. The P450 isozymes CYP1A2 expressed in A. thaliana were examined regarding the herbicide simazine (SIM). Transgenic A. thaliana plants expressing CYP1A2 gene showed significant resistance to SIM supplemented either in plant growth medium or sprayed on foliar parts. The results showed that SIM produces harmful effect on both rosette diameter and primary root length of the wild type (WT) plants. In transgenic A. thaliana lines, the rosette diameter and primary root length were not affected by SIM concentrations used in this experiment. The results indicate that CYP1A2 can be used as a selectable marker for plant transformation, allowing efficient selection of transgenic lines in growth medium and/or in soil-grown plants. The transgenic A. thaliana plants exhibited a healthy growth using doses of up to 250 μmol SIM treatments, while the non-transgenic A. thaliana plants were severely damaged with doses above 50 μmol SIM treatments. The transgenic A. thaliana plants can be used as phytoremediator of environmental SIM contaminants.

  4. Constitutional reform as process

    OpenAIRE

    Schultze, Rainer-Olaf (Prof.)

    2000-01-01

    Constitutional reform as process. - In: The politics of constitutional reform in North America / Rainer-Olaf Schultze ... (eds.). - Opladen : Leske + Budrich, 2000. - S. 11-31. - (Politikwissenschaftliche paperbacks ; 30)

  5. Transnational Constitutional Law

    NARCIS (Netherlands)

    Zumbansen, P (Peer); K.I. Bhatt (Kinnari)

    2018-01-01

    textabstractThis chapter provides an overview of the emerging field of transnational constitutional law (TCL). Whilst questions of constitutional law are typically discussed in the context of a specific domestic legal setting, a salient strategy of TCL is to understand constitutional law and its

  6. Screening for MPL mutations in essential thrombocythemia and primary myelofibrosis: normal Mpl expression and absence of constitutive STAT3 and STAT5 activation in MPLW515L-positive platelets.

    Science.gov (United States)

    Glembotsky, Ana C; Korin, Laura; Lev, Paola R; Chazarreta, Carlos D; Marta, Rosana F; Molinas, Felisa C; Heller, Paula G

    2010-05-01

    To evaluate the frequency of MPL W515L, W515K and S505N mutations in essential thrombocythemia (ET) and primary myelofibrosis (PMF) and to determine whether MPLW515L leads to impaired Mpl expression, constitutive STAT3 and STAT5 activation and enhanced response to thrombopoietin (TPO). Mutation detection was performed by allele-specific PCR and sequencing. Platelet Mpl expression was evaluated by flow cytometry, immunoblotting and real-time RT-PCR. Activation of STAT3 and STAT5 before and after stimulation with increasing concentrations of TPO was studied by immunoblotting. Plasma TPO was measured by ELISA. MPLW515L was detected in 1 of 100 patients with ET and 1 of 11 with PMF. Platelets from the PMF patient showed 100% mutant allele, which was Mpl surface and total protein expression were normal, and TPO levels were mildly increased in the MPLW515L-positive ET patient, while MPL transcripts did not differ from controls in both MPLW515L-positive patients. Constitutive STAT3 and STAT5 phosphorylation was absent and dose response to TPO-induced phosphorylation was not enhanced. The low frequency of MPL mutations in this cohort is in agreement with previous studies. The finding of normal Mpl levels in MPLW515L-positive platelets indicates this mutation does not lead to dysregulated Mpl expression, as frequently shown for myeloproliferative neoplasms. The lack of spontaneous STAT3 and STAT5 activation and the normal response to TPO is unexpected as MPLW515L leads to constitutive receptor activation and hypersensitivity to TPO in experimental models.

  7. Evolutionary origins of Brassicaceae specific genes in Arabidopsis thaliana

    Science.gov (United States)

    2011-01-01

    lineages. We demonstrate that lineage-specific genes have high tissue specificity and low expression levels across multiple tissues and developmental stages. Finally, stress responsiveness is identified as a distinct feature of Brassicaceae-specific genes; where these LSGs are enriched for genes responsive to a wide range of abiotic stresses. Conclusion Improving our understanding of the origins of lineage-specific genes is key to gaining insights regarding how novel genes can arise and acquire functionality in different lineages. This study comprehensively identifies all of the Brassicaceae-specific genes in Arabidopsis thaliana and identifies how the majority of such lineage-specific genes have arisen. The analysis allows the relative importance (and prevalence) of different evolutionary routes to the genesis of novel ORFs within lineages to be assessed. Insights regarding the functional roles of lineage-specific genes are further advanced through identification of enrichment for stress responsiveness in lineage-specific genes, highlighting their likely importance for environmental adaptation strategies. PMID:21332978

  8. UNDERSTANDING INFORMAL CONSTITUTIONAL CHANGE

    Directory of Open Access Journals (Sweden)

    Stephen M. Griffin

    2016-01-01

    Full Text Available Amid much recent American work on the problem of informal constitutional change, this article stakes out a distinctive position. I argue that theories of constitutional change in the US must address the question of the relationship between the “small c” and “big C” Constitution and treat seriously the possibility of conflict between them. I stress the unavoidable role the text of the Constitution and structural doctrines of federalism and separation of powers play in this relationship and thus in constitutional change, both formal and informal. I therefore counsel against theories that rely solely on a practice-based approach or analogies between “small c” constitutional developments and British or Commonwealth traditions of the “unwritten” constitution and constitutional “conventions.” The alternative I advocate is to approach constitutional change from a historicist perspective that focuses attention on state building and the creation of new institutional capacities. This approach will allow us to make progress by highlighting that there can be multiple constitutional orders in a given historical era, thus accounting for the conflictual nature of contemporary constitutional development in the US.

  9. Genome wide association mapping for the tolerance to the polyamine oxidase inhibitor guazatine in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Kostadin Evgeniev eAtanasov

    2016-04-01

    Full Text Available Guazatine is a potent inhibitor of polyamine oxidase (PAO activity. In agriculture, guazatine is used as non-systemic contact fungicide efficient in the protection of cereals and citrus fruits against disease. The composition of guazatine is complex, mainly constituted by a mixture of synthetic guanidated polyamines (polyaminoguanidines. Here we have studied the effects from exposure to guazatine in the weed Arabidopsis thaliana. We report that micromolar concentrations of guazatine are sufficient to inhibit growth of Arabidopsis seedlings and induce chlorosis, whereas germination is barely affected. We observed the occurrence of quantitative variation in the response to guazatine between 107 randomly chosen Arabidopsis accessions. This enabled us to undertake genome-wide association (GWA mapping that identified a locus on chromosome one associated with guazatine tolerance. CHLOROPHYLLASE 1 (CLH1 within this locus was studied as candidate gene, together with its paralog (CLH2. The analysis of independent clh1-2, clh1-3, clh2-3, clh2-2 and double clh1-2 clh2-3 mutant alleles indicated that CLH1 and/or CLH2 loss-of-function or expression down-regulation promote guazatine tolerance in Arabidopsis. We report a natural mechanism by which Arabidopsis populations can overcome toxicity by the fungicide guazatine.

  10. Two alleles of the AtCesA3 gene in Arabidopsis thaliana display intragenic complementation.

    Science.gov (United States)

    Pysh, Leonard D

    2015-09-01

    Cellulose is the most abundant biomolecule on the planet, yet the mechanism by which it is synthesized by higher plants remains largely unknown. In Arabidopsis thaliana (L.) Heynh, synthesis of cellulose in the primary cell wall requires three different cellulose synthase genes (AtCesA1, AtCesA3, and AtCesA6-related genes [AtCesA2, AtCesA5, and AtCesA6]). The multiple response expansion1 (mre1) mutant contains a hypomorphic AtCesA3 allele that results in significantly shorter, expanded roots. Crosses between mre1 and another allele of AtCesA3 (constitutive expression of VSP1, cev1) yielded an F1 with roots considerably longer and thinner than either parent, suggesting intragenic complementation. The F2 generation resulting from self-crossing these F1 showed three different root phenotypes: roots like mre1, roots like cev1, and roots like the F1. The segregation patterns of the three root phenotypes in multiple F2 and F3 generations were determined. Multiple characteristics of the roots and shoots were analyzed both qualitatively and quantitatively at different developmental stages, both on plates and on soil. The trans-heterozygous plants differed significantly from the parental mre1 and cev1 lines. The two alleles display intragenic complementation. A classic genetic interpretation of these results would suggest that cellulose synthesis requires homo-multimerization of cellulose synthase monomers. © 2015 Botanical Society of America.

  11. Bioavailability of nanoparticulate hematite to Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Marusenko, Yevgeniy; Shipp, Jessie; Hamilton, George A.; Morgan, Jennifer L.L.; Keebaugh, Michael; Hill, Hansina; Dutta, Arnab; Zhuo, Xiaoding; Upadhyay, Nabin; Hutchings, James; Herckes, Pierre; Anbar, Ariel D.; Shock, Everett; Hartnett, Hilairy E.

    2013-01-01

    The environmental effects and bioavailability of nanoparticulate iron (Fe) to plants are currently unknown. Here, plant bioavailability of synthesized hematite Fe nanoparticles was evaluated using Arabidopsis thaliana (A. thaliana) as a model. Over 56-days of growing wild-type A. thaliana, the nanoparticle-Fe and no-Fe treatments had lower plant biomass, lower chlorophyll concentrations, and lower internal Fe concentrations than the Fe-treatment. Results for the no-Fe and nanoparticle-Fe treatments were consistently similar throughout the experiment. These results suggest that nanoparticles (mean diameter 40.9 nm, range 22.3–67.0 nm) were not taken up and therefore not bioavailable to A. thaliana. Over 14-days growing wild-type and transgenic (Type I/II proton pump overexpression) A. thaliana, the Type I plant grew more than the wild-type in the nanoparticle-Fe treatment, suggesting Type I plants cope better with Fe limitation; however, the nanoparticle-Fe and no-Fe treatments had similar growth for all plant types. -- Highlights: ► Iron nanoparticles were synthesized and assessed for bioavailability to Arabidopsis. ► Arabidopsis grew better in the presence of EDTA-bound iron than nanoparticulate iron. ► Arabidopsis grew the same in the presence of nanoparticulate iron compared to no iron. -- Synthesized iron nanoparticles were not bioavailable to Arabidopsis thaliana in agar nutrient media

  12. Constitutive expression of interferon-induced human MxA protein in transgenic tobacco plants does not confer resistance to a variety of RNA viruses

    NARCIS (Netherlands)

    Frese, M.; Prins, M.; Ponten, A.; Goldbach, R.W.; Haller, O.; Zeltz, P.

    2000-01-01

    MxA is a key component in the interferon-induced antiviral defense in humans. After viral infections, MxA is rapidly induced and accumulates in the cytoplasm. The multiplication of many RNA viruses,including all bunyaviruses tested so far, is inhibited by MxA. These findings prompted us to express

  13. Bt rice harbouring cry genes controlled by a constitutive or wound-inducible promoter: protection and transgene expression under Mediterranean field conditions.

    Science.gov (United States)

    Breitler, Jean Christophe; Vassal, Jean Michel; del Mar Catala, Maria; Meynard, Donaldo; Marfà, Victoria; Melé, Enric; Royer, Monique; Murillo, Isabel; San Segundo, Blanca; Guiderdoni, Emmanuel; Messeguer, Joaquima

    2004-09-01

    Seven homozygous transgenic lines of two European commercial cultivars of rice (Ariete (A) and Senia (S)), harbouring the cry1B or cry1Aa Bacillus thuringiensis (Bt) delta-endotoxin genes, were field evaluated for protection from striped stem borer (SSB) (Chilo suppressalis) damage during the 2001 and 2002 summer crop seasons in the Delta de l'Ebre region, Spain. The plant codon-optimized toxin gene was placed under the control of the promoter of either the constitutive ubi1 gene or the wound-inducible mpi gene from maize. Stable, high-level, insecticidal protein accumulation was observed throughout root, leaf and seed tissues of field-grown plants harbouring the cry1B (lines A64.1, A33.1, A3.4 and S98.9) or cry1Aa (lines S05.1 and A19.14) genes under the control of the ubi1 promoter. Conversely, no toxin was detected in unwounded vegetative tissues of the A9.1 line harbouring the cry1B gene controlled by the mpi promoter, indicating that natural environmental stresses did not trigger the activity of the wound-inducible promoter. However, the toxin accumulated at 0.2% total soluble proteins in A9.1 sheath tissue exhibiting brown lesions resulting from SSB damage. The agronomical traits and performance of the transgenic lines were generally comparable with parental controls, except in the two lines accumulating Cry1Aa, which exhibited a high frequency of plants non-true to type. Natural infestation was assisted with manual infestations of L2/L3 SSB larvae in border control plants surrounding the experimental plots, which served as a reservoir for the second-cycle SSB population. The observation of damage (brown lesions and dead hearts) during the crop season and dissection of plants at harvest stage revealed a range of protection amongst the transgenic lines, which was highly consistent with the level of toxin accumulation and with previous experience in greenhouse assays. Lines A3.4 and S05.1 were found to exhibit stable and full protection against SSB attacks

  14. Constitutive expression of a putative high-affinity nitrate transporter in Nicotiana plumbaginifolia: evidence for post-transcriptional regulation by a reduced nitrogen source.

    Science.gov (United States)

    Fraisier, V; Gojon, A; Tillard, P; Daniel-Vedele, F

    2000-08-01

    The NpNRT2.1 gene encodes a putative inducible component of the high-affinity nitrate (NO3-) uptake system in Nicotiana plumbaginifolia. Here we report functional and physiological analyses of transgenic plants expressing the NpNRT2.1 coding sequence fused to the CaMV 35S or rolD promoters. Irrespective of the level of NO3- supplied, NO3- contents were found to be remarkably similar in wild-type and transgenic plants. Under specific conditions (growth on 10 mM NO3-), the steady-state NpNRT2. 1 mRNA level resulting from the deregulated transgene expression was accompanied by an increase in 15NO3- influx measured in the low concentration range. This demonstrates for the first time that the NRT2.1 sequence codes a limiting element of the inducible high-affinity transport system. Both 15NO3- influx and mRNA levels decreased in the wild type after exposure to ammonium, in agreement with previous results from many species. Surprisingly, however, influx was also markedly decreased in transgenic plants, despite stable levels of transgene expression in independent transformants after ammonium addition. We conclude that the conditions associated with the supply of a reduced nitrogen source such as ammonium, or with the generation of a further downstream metabolite, probably exert a repressive effect on NO3- influx at both transcriptional and post-transcriptional levels.

  15. High proportion of PD-1-expressing CD4+ T cells in adipose tissue constitutes an immunomodulatory microenvironment that may support HIV persistence.

    Science.gov (United States)

    Damouche, Abderaouf; Pourcher, Guillaume; Pourcher, Valérie; Benoist, Stéphane; Busson, Elodie; Lataillade, Jean-Jacques; Le Van, Mélanie; Lazure, Thierry; Adam, Julien; Favier, Benoit; Vaslin, Bruno; Müller-Trutwin, Michaela; Lambotte, Olivier; Bourgeois, Christine

    2017-12-01

    We and others have demonstrated that adipose tissue is a reservoir for HIV. Evaluation of the mechanisms responsible for viral persistence may lead to ways of reducing these reservoirs. Here, we evaluated the immune characteristics of adipose tissue in HIV-infected patients receiving antiretroviral therapy (ART) and in non-HIV-infected patients. We notably sought to determine whether adipose tissue's intrinsic properties and/or HIV induced alteration of the tissue environment may favour viral persistence. ART-controlled HIV infection was associated with a difference in the CD4/CD8 T-cell ratio and an elevated proportion of Treg cells in subcutaneous adipose tissue. No changes in Th1, Th2 and Th17 cell proportions or activation markers expression on T cell (Ki-67, HLA-DR) could be detected, and the percentage of CD69-expressing resident memory CD4 + T cells was not affected. Overall, our results indicate that adipose-tissue-resident CD4 + T cells are not extensively activated during HIV infection. PD-1 was expressed by a high proportion of tissue-resident memory CD4 + T cells in both HIV-infected patients and non-HIV-infected patients. Our findings suggest that adipose tissue's intrinsic immunomodulatory properties may limit immune activation and thus may strongly contribute to viral persistence. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Constitutive Activity of the Arabidopsis MAP Kinase 3 Confers Resistance to Pseudomonas syringae and Drives Robust Immune Responses

    KAUST Repository

    Lang, Julien

    2017-08-02

    Mitogen Activated Protein Kinases (MAPKs) are known to be important mediators of plant responses to biotic and abiotic stresses. In a recent report, we enlarged the understanding of the Arabidopsis thaliana MPK3 functions showing that the expression of a constitutively active (CA) form of the protein led to auto-immune phenotypes. CA-MPK3 plants are dwarf and display defense responses that are characterized by the accumulation of salicylic acid and phytoalexins as well as by the upregulation of several defense genes. Consistently with these data, we present here results demonstrating that, compared to wild type controls, CA-MPK3 plants are more resistant to the hemibiotrophic pathogen Pseudomonas syringae DC3000. Based on our previous work, we also discuss the mechanisms of robust plant immunity controlled by sustained MPK3 activity, focusing especially on the roles of disease resistance proteins.

  17. A composite transcriptional signature differentiates responses towards closely related herbicides in Arabidopsis thaliana and brassica napus

    Science.gov (United States)

    In this study, genome-wide expression profiling based on Affymetrix ATH1 arrays was used to identify discriminating responses of Arabidopsis thaliana to five herbicides, which contain active ingredients targeting two different branches of amino acid biosynthesis. One herbicide co...

  18. Transnational Constitutional Law

    OpenAIRE

    Zumbansen, P (Peer); Bhatt, Kinnari

    2018-01-01

    textabstractThis chapter provides an overview of the emerging field of transnational constitutional law (TCL). Whilst questions of constitutional law are typically discussed in the context of a specific domestic legal setting, a salient strategy of TCL is to understand constitutional law and its values by placing them ‘in context’ with existing and evolving cultural norms and political, social and economic discourses and struggles. Drawing on socio-legal investigations into the relationships ...

  19. Comprehensive genome-wide survey, genomic constitution and expression profiling of the NAC transcription factor family in foxtail millet (Setaria italica L..

    Directory of Open Access Journals (Sweden)

    Swati Puranik

    Full Text Available The NAC proteins represent a major plant-specific transcription factor family that has established enormously diverse roles in various plant processes. Aided by the availability of complete genomes, several members of this family have been identified in Arabidopsis, rice, soybean and poplar. However, no comprehensive investigation has been presented for the recently sequenced, naturally stress tolerant crop, Setaria italica (foxtail millet that is famed as a model crop for bioenergy research. In this study, we identified 147 putative NAC domain-encoding genes from foxtail millet by systematic sequence analysis and physically mapped them onto nine chromosomes. Genomic organization suggested that inter-chromosomal duplications may have been responsible for expansion of this gene family in foxtail millet. Phylogenetically, they were arranged into 11 distinct sub-families (I-XI, with duplicated genes fitting into one cluster and possessing conserved motif compositions. Comparative mapping with other grass species revealed some orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of genes. The evolutionary significance as duplication and divergence of NAC genes based on their amino acid substitution rates was understood. Expression profiling against various stresses and phytohormones provides novel insights into specific and/or overlapping expression patterns of SiNAC genes, which may be responsible for functional divergence among individual members in this crop. Further, we performed structure modeling and molecular simulation of a stress-responsive protein, SiNAC128, proffering an initial framework for understanding its molecular function. Taken together, this genome-wide identification and expression profiling unlocks new avenues for systematic functional analysis of novel NAC gene family candidates which may be applied for improvising stress adaption in plants.

  20. Comprehensive genome-wide survey, genomic constitution and expression profiling of the NAC transcription factor family in foxtail millet (Setaria italica L.).

    Science.gov (United States)

    Puranik, Swati; Sahu, Pranav Pankaj; Mandal, Sambhu Nath; B, Venkata Suresh; Parida, Swarup Kumar; Prasad, Manoj

    2013-01-01

    The NAC proteins represent a major plant-specific transcription factor family that has established enormously diverse roles in various plant processes. Aided by the availability of complete genomes, several members of this family have been identified in Arabidopsis, rice, soybean and poplar. However, no comprehensive investigation has been presented for the recently sequenced, naturally stress tolerant crop, Setaria italica (foxtail millet) that is famed as a model crop for bioenergy research. In this study, we identified 147 putative NAC domain-encoding genes from foxtail millet by systematic sequence analysis and physically mapped them onto nine chromosomes. Genomic organization suggested that inter-chromosomal duplications may have been responsible for expansion of this gene family in foxtail millet. Phylogenetically, they were arranged into 11 distinct sub-families (I-XI), with duplicated genes fitting into one cluster and possessing conserved motif compositions. Comparative mapping with other grass species revealed some orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of genes. The evolutionary significance as duplication and divergence of NAC genes based on their amino acid substitution rates was understood. Expression profiling against various stresses and phytohormones provides novel insights into specific and/or overlapping expression patterns of SiNAC genes, which may be responsible for functional divergence among individual members in this crop. Further, we performed structure modeling and molecular simulation of a stress-responsive protein, SiNAC128, proffering an initial framework for understanding its molecular function. Taken together, this genome-wide identification and expression profiling unlocks new avenues for systematic functional analysis of novel NAC gene family candidates which may be applied for improvising stress adaption in plants.

  1. Effect of nickel on the organization of actin filaments in Arabidopsis thaliana primary root cells

    International Nuclear Information System (INIS)

    Goryunova, I.I.; Krasilenko, Yu.A.; Emets, A.I.; Blyum, Ya.B.

    2016-01-01

    The influence of one of the most toxic heavy metals - nickel (Ni 2+ ) - on the organization of actin filaments (microfilaments) of different types of Arabidopsis thaliana (L.) root cells is studied in living cells by the laser scanning microscopy. To visualize microfilaments, the A. thaliana line expressing chimeric gene gfp-fabd2 was used. Ni 2+ leads to a significant inhibition of the growth of the main root and disturbs its morphology, causing the swelling of epidermal cells and inducing a large number of abnormally long root hairs. For the first time, it has been shown that Ni 2+ disturbs the organization of actin filaments in cells, leading to morphological changes of a root as the main organ, being the first exposed to the intoxication by soil pollutants. It is found that the most sensitive to its action are actin filaments of epidermal cells of all growth zones of A. thaliana root

  2. Constitutive expression of the AHR signaling pathway in a bovine mammary epithelial cell line and modulation by dioxin-like PCB and other AHR ligands.

    Science.gov (United States)

    Girolami, Flavia; Spalenza, Veronica; Manzini, Livio; Carletti, Monica; Nebbia, Carlo

    2015-01-05

    Environmental pollutants, such as dioxin-like (DL) PCBs, benzo(a) pyrene (B[a]P), and flavonoids are aryl hydrocarbon receptor (AHR) ligands and may be excreted in dairy milk. The expression of AHR-target genes, particularly those involved in xenobiotic biotransformation, and their modulation by two DL-PCBs, B[a]P, and β-naphthoflavone was investigated in a bovine mammary epithelial cell line (BME-UV). As assessed by quantitative PCR, BME-UV cells expressed a functional AHR signaling pathway. All the AHR ligands induced a concentration-related increase in the transcription of cytochrome P450 1A1 and 1B1, known to be implicated in the bioactivation of several xenobiotics. Conversely, genes encoding for antioxidant and detoxifying enzymes, like quinone oxidoreductase or glutathione S-transferase A2, were not affected or even depressed. This study demonstrates the occurrence and the modulation by different AHR-ligands of genes involved in xenobiotic metabolism in BME-UV cells, with the potential generation of (re) active metabolites that may damage mammary tissue and/or affect animal or human health via the contaminated milk. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. The effect of high concentrations of glufosinate ammonium on the yield components of transgenic spring wheat (Triticum aestivum L.) constitutively expressing the bar gene.

    Science.gov (United States)

    Áy, Zoltán; Mihály, Róbert; Cserháti, Mátyás; Kótai, Éva; Pauk, János

    2012-01-01

    We present an experiment done on a bar(+) wheat line treated with 14 different concentrations of glufosinate ammonium-an effective component of nonselective herbicides-during seed germination in a closed experimental system. Yield components as number of spikes per plant, number of grains per spike, thousand kernel weight, and yield per plant were thoroughly analysed and statistically evaluated after harvesting. We found that a concentration of glufosinate ammonium 5000 times the lethal dose was not enough to inhibit the germination of transgenic plants expressing the bar gene. Extremely high concentrations of glufosinate ammonium caused a bushy phenotype, significantly lower numbers of grains per spike, and thousand kernel weights. Concerning the productivity, we observed that concentrations of glufosinate ammonium 64 times the lethal dose did not lead to yield depression. Our results draw attention to the possibilities implied in the transgenic approaches.

  4. The Effect of High Concentrations of Glufosinate Ammonium on the Yield Components of Transgenic Spring Wheat (Triticum aestivum L. Constitutively Expressing the bar Gene

    Directory of Open Access Journals (Sweden)

    Zoltán Áy

    2012-01-01

    Full Text Available We present an experiment done on a bar+ wheat line treated with 14 different concentrations of glufosinate ammonium—an effective component of nonselective herbicides—during seed germination in a closed experimental system. Yield components as number of spikes per plant, number of grains per spike, thousand kernel weight, and yield per plant were thoroughly analysed and statistically evaluated after harvesting. We found that a concentration of glufosinate ammonium 5000 times the lethal dose was not enough to inhibit the germination of transgenic plants expressing the bar gene. Extremely high concentrations of glufosinate ammonium caused a bushy phenotype, significantly lower numbers of grains per spike, and thousand kernel weights. Concerning the productivity, we observed that concentrations of glufosinate ammonium 64 times the lethal dose did not lead to yield depression. Our results draw attention to the possibilities implied in the transgenic approaches.

  5. Constitutive Expression of a miR319 Gene Alters Plant Development and Enhances Salt and Drought Tolerance in Transgenic Creeping Bentgrass1[W][OA

    Science.gov (United States)

    Zhou, Man; Li, Dayong; Li, Zhigang; Hu, Qian; Yang, Chunhua; Zhu, Lihuang; Luo, Hong

    2013-01-01

    MicroRNA319 (miR319) is one of the first characterized and conserved microRNA families in plants and has been demonstrated to target TCP (for TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTORS [PCF]) genes encoding plant-specific transcription factors. MiR319 expression is regulated by environmental stimuli, suggesting its involvement in plant stress response, although experimental evidence is lacking and the underlying mechanism remains elusive. This study investigates the role that miR319 plays in the plant response to abiotic stress using transgenic creeping bentgrass (Agrostis stolonifera) overexpressing a rice (Oryza sativa) miR319 gene, Osa-miR319a. We found that transgenic plants overexpressing Osa-miR319a displayed morphological changes and exhibited enhanced drought and salt tolerance associated with increased leaf wax content and water retention but reduced sodium uptake. Gene expression analysis indicated that at least four putative miR319 target genes, AsPCF5, AsPCF6, AsPCF8, and AsTCP14, and a homolog of the rice NAC domain gene AsNAC60 were down-regulated in transgenic plants. Our results demonstrate that miR319 controls plant responses to drought and salinity stress. The enhanced abiotic stress tolerance in transgenic plants is related to significant down-regulation of miR319 target genes, implying their potential for use in the development of novel molecular strategies to genetically engineer crop species for enhanced resistance to environmental stress. PMID:23292790

  6. Arabidopsis thaliana mTERF proteins: evolution and functional classification

    Directory of Open Access Journals (Sweden)

    Tatjana eKleine

    2012-10-01

    Full Text Available Organellar gene expression (OGE is crucial for plant development, photosynthesis and respiration, but our understanding of the mechanisms that control it is still relatively poor. Thus, OGE requires various nucleus-encoded proteins that promote transcription, splicing, trimming and editing of organellar RNAs, and regulate translation. In metazoans, proteins of the mitochondrial Transcription tERmination Factor (mTERF family interact with the mitochondrial chromosome and regulate transcriptional initiation and termination. Sequencing of the Arabidopsis thaliana genome led to the identification of a diversified MTERF gene family but, in contrast to mammalian mTERFs, knowledge about the function of these proteins in photosynthetic organisms is scarce. In this hypothesis article, I show that tandem duplications and one block duplication contributed to the large number of MTERF genes in A. thaliana, and propose that the expansion of the family is related to the evolution of land plants. The MTERF genes - especially the duplicated genes - display a number of distinct mRNA accumulation patterns, suggesting functional diversification of mTERF proteins to increase adaptability to environmental changes. Indeed, hypothetical functions for the different mTERF proteins can be predicted using co-expression analysis and gene ontology annotations. On this basis, mTERF proteins can be sorted into five groups. Members of the chloroplast and chloroplast-associated clusters are principally involved in chloroplast gene expression, embryogenesis and protein catabolism, while representatives of the mitochondrial cluster seem to participate in DNA and RNA metabolism in that organelle. Moreover, members of the mitochondrion-associated cluster and the low expression group may act in the nucleus and/or the cytosol. As proteins involved in OGE and presumably nuclear gene expression, mTERFs are ideal candidates for the coordination of the expression of organelle and nuclear

  7. Constitutive over-expression of rice chymotrypsin protease inhibitor gene OCPI2 results in enhanced growth, salinity and osmotic stress tolerance of the transgenic Arabidopsis plants.

    Science.gov (United States)

    Tiwari, Lalit Dev; Mittal, Dheeraj; Chandra Mishra, Ratnesh; Grover, Anil

    2015-07-01

    Protease inhibitors are involved primarily in defense against pathogens. In recent years, these proteins have also been widely implicated in response of plants to diverse abiotic stresses. Rice chymotrypsin protease inhibitor gene OCPI2 is highly induced under salt and osmotic stresses. The construct containing the complete coding sequence of OCPI2 cloned downstream to CaMV35S promoter was transformed in Arabidopsis and single copy, homozygous transgenic lines were produced. The transgenic plants exhibited significantly enhanced tolerance to NaCl, PEG and mannitol stress as compared to wild type plants. Importantly, the vegetative and reproductive growth of transgenic plants under unstressed, control conditions was also enhanced: transgenic plants were more vigorous than wild type, resulting into higher yield in terms of silique number. The RWC values and membrane stability index of transgenic in comparison to wild type plants was higher. Higher proline content was observed in the AtOCPI2 lines, which was associated with higher transcript expression of pyrroline-5-carboxylate synthase and lowered levels of proline dehydrogenase genes. The chymotrypsin protease activities were lower in the transgenic as against wild type plants, under both unstressed, control as well as stressed conditions. It thus appears that rice chymotrypsin protease inhibitor gene OCPI2 is a useful candidate gene for genetic improvement of plants against salt and osmotic stress. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  8. The effect of constitutive over-expression of insulin-like growth factor 1 on the cognitive function in aged mice.

    Science.gov (United States)

    Hu, Ankang; Yuan, Honghua; Wu, Lianlian; Chen, Renjin; Chen, Quangang; Zhang, Tengye; Wang, Zhenzhen; Liu, Peng; Zhu, Xiaorong

    2016-01-15

    The neurotrophic factor insulin-like growth factor (IGF)-1 promotes neurogenesis in the mammalian brain and provides protection against brain injury. However, studies regarding the effects of IGF-1 on cognitive function in aged mice remain limited. We investigated the effects of overexpression of IGF-1 specifically in neural stem cells of the hippocampal dentate gyrus on the recognitive function in 18-month-old transgenic mice. Immunohistocytochemistry and Nissl staining revealed the increased population of BrdU-positive cells as well as the upregulated expression of Nestin and neuronal nuclei (NeuN), respective markers for neural progenitors and neurons, in the hippocampus of the aged IGF-1 transgenic mice versus the wild-type, suggesting that IGF-1 overexpression promotes neurogenesis. In addition, the IGF-1 receptor (IGF-1R), the phosphorylation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and extracellular signal-regulated kinase (ERK) were enhanced in the transgenic mice than in the wild-type. Transgenic mice also showed superior performance in the Morris water maze and step-down memory tests to their wild-type counterparts. Moreover, the learning and memory abilities of transgenic mice were significantly undermined with the blockage of CaMKII and ERK signaling pathway. Accordingly, our findings indicated that IGF-1 may mitigate the aged-associated cognitive decline via promoting neurogenesis in the hippocampus and activating CaMKII and ERK signaling by binding with IGF-1R. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. A Regulatory Network Analysis of Orphan Genes in Arabidopsis Thaliana

    Science.gov (United States)

    Singh, Pramesh; Chen, Tianlong; Arendsee, Zebulun; Wurtele, Eve S.; Bassler, Kevin E.

    Orphan genes, which are genes unique to each particular species, have recently drawn significant attention for their potential usefulness for organismal robustness. Their origin and regulatory interaction patterns remain largely undiscovered. Recently, methods that use the context likelihood of relatedness to infer a network followed by modularity maximizing community detection algorithms on the inferred network to find the functional structure of regulatory networks were shown to be effective. We apply improved versions of these methods to gene expression data from Arabidopsis thaliana, identify groups (clusters) of interacting genes with related patterns of expression and analyze the structure within those groups. Focusing on clusters that contain orphan genes, we compare the identified clusters to gene ontology (GO) terms, regulons, and pathway designations and analyze their hierarchical structure. We predict new regulatory interactions and unravel the structure of the regulatory interaction patterns of orphan genes. Work supported by the NSF through Grants DMR-1507371 and IOS-1546858.

  10. Nitrile-specifier Proteins Involved in Glucosinolate Hydrolysis in Arabidopsis thaliana*S⃞

    Science.gov (United States)

    Kissen, Ralph; Bones, Atle M.

    2009-01-01

    Glucosinolates are plant secondary metabolites present in Brassicaceae plants such as the model plant Arabidopsis thaliana. Intact glucosinolates are believed to be biologically inactive, whereas degradation products after hydrolysis have multiple roles in growth regulation and defense. The degradation of glucosinolates is catalyzed by thioglucosidases called myrosinases and leads by default to the formation of isothiocyanates. The interaction of a protein called epithiospecifier protein (ESP) with myrosinase diverts the reaction toward the production of epithionitriles or nitriles depending on the glucosinolate structure. Here we report the identification of a new group of nitrile-specifier proteins (AtNSPs) in A. thaliana able to generate nitriles in conjunction with myrosinase and a more detailed characterization of one member (AtNSP2). Recombinant AtNSP2 expressed in Escherichia coli was used to test its impact on the outcome of glucosinolate hydrolysis using a gas chromatography-mass spectrometry approach. AtNSP proteins share 30–45% sequence homology with A. thaliana ESP. Although AtESP and AtNSP proteins can switch myrosinase-catalyzed degradation of 2-propenylglucosinolate from isothiocyanate to nitrile, only AtESP generates the corresponding epithionitrile. Using the aromatic benzylglucosinolate, recombinant AtNSP2 is also able to direct product formation to the nitrile. Analysis of glucosinolate hydrolysis profiles of transgenic A. thaliana plants overexpressing AtNSP2 confirms its nitrile-specifier activity in planta. In silico expression analysis reveals distinctive expression patterns of AtNSPs, which supports a biological role for these proteins. In conclusion, we show that AtNSPs belonging to a new family of A. thaliana proteins structurally related to AtESP divert product formation from myrosinase-catalyzed glucosinolate hydrolysis and, thereby, likely affect the biological consequences of glucosinolate degradation. We discuss similarities and

  11. Functional characterization of Arabidopsis thaliana transthyretin-like protein.

    Science.gov (United States)

    Pessoa, João; Sárkány, Zsuzsa; Ferreira-da-Silva, Frederico; Martins, Sónia; Almeida, Maria R; Li, Jianming; Damas, Ana M

    2010-02-18

    Arabidopsis thaliana transthyretin-like (TTL) protein is a potential substrate in the brassinosteroid signalling cascade, having a role that moderates plant growth. Moreover, sequence homology revealed two sequence domains similar to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) decarboxylase (N-terminal domain) and 5-hydroxyisourate (5-HIU) hydrolase (C-terminal domain). TTL is a member of the transthyretin-related protein family (TRP), which comprises a number of proteins with sequence homology to transthyretin (TTR) and the characteristic C-terminal sequence motif Tyr-Arg-Gly-Ser. TRPs are single domain proteins that form tetrameric structures with 5-HIU hydrolase activity. Experimental evidence is fundamental for knowing if TTL is a tetrameric protein, formed by the association of the 5-HIU hydrolase domains and, in this case, if the structural arrangement allows for OHCU decarboxylase activity. This work reports about the biochemical and functional characterization of TTL. The TTL gene was cloned and the protein expressed and purified for biochemical and functional characterization. The results show that TTL is composed of four subunits, with a moderately elongated shape. We also found evidence for 5-HIU hydrolase and OHCU decarboxylase activities in vitro, in the full-length protein. The Arabidopsis thaliana transthyretin-like (TTL) protein is a tetrameric bifunctional enzyme, since it has 5-HIU hydrolase and OHCU decarboxylase activities, which were simultaneously observed in vitro.

  12. Functional characterization of Arabidopsis thaliana transthyretin-like protein

    Directory of Open Access Journals (Sweden)

    Almeida Maria R

    2010-02-01

    Full Text Available Abstract Background Arabidopsis thaliana transthyretin-like (TTL protein is a potential substrate in the brassinosteroid signalling cascade, having a role that moderates plant growth. Moreover, sequence homology revealed two sequence domains similar to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU decarboxylase (N-terminal domain and 5-hydroxyisourate (5-HIU hydrolase (C-terminal domain. TTL is a member of the transthyretin-related protein family (TRP, which comprises a number of proteins with sequence homology to transthyretin (TTR and the characteristic C-terminal sequence motif Tyr-Arg-Gly-Ser. TRPs are single domain proteins that form tetrameric structures with 5-HIU hydrolase activity. Experimental evidence is fundamental for knowing if TTL is a tetrameric protein, formed by the association of the 5-HIU hydrolase domains and, in this case, if the structural arrangement allows for OHCU decarboxylase activity. This work reports about the biochemical and functional characterization of TTL. Results The TTL gene was cloned and the protein expressed and purified for biochemical and functional characterization. The results show that TTL is composed of four subunits, with a moderately elongated shape. We also found evidence for 5-HIU hydrolase and OHCU decarboxylase activities in vitro, in the full-length protein. Conclusions The Arabidopsis thaliana transthyretin-like (TTL protein is a tetrameric bifunctional enzyme, since it has 5-HIU hydrolase and OHCU decarboxylase activities, which were simultaneously observed in vitro.

  13. Novel Ribonuclease Activity Differs between Fibrillarins from Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Ulises Rodriguez-Corona

    2017-10-01

    Full Text Available Fibrillarin is one of the most important nucleolar proteins that have been shown as essential for life. Fibrillarin localizes primarily at the periphery between fibrillar center and dense fibrillar component as well as in Cajal bodies. In most plants there are at least two different genes for fibrillarin. In Arabidopsis thaliana both genes show high level of expression in transcriptionally active cells. Here, we focus on two important differences between A. thaliana fibrillarins. First and most relevant is the enzymatic activity by AtFib2. The AtFib2 shows a novel ribonuclease activity that is not seen with AtFib1. Second is a difference in the ability to interact with phosphoinositides and phosphatidic acid between both proteins. We also show that the novel ribonuclease activity as well as the phospholipid binding region of fibrillarin is confine to the GAR domain. The ribonuclease activity of fibrillarin reveals in this study represents a new role for this protein in rRNA processing.

  14. Ethylene production and constitutive expression of ethylene receptors and ethylene signal transduction during grain filling in apical and basal spikelets of compact-and lax-panicle rice (Oryza sativa cultivars

    Directory of Open Access Journals (Sweden)

    Sudhanshu Sekhar

    2017-12-01

    Full Text Available Grain yields in modern super rice cultivars do not always meet the expectations because many spikelets are located on secondary branches in closely packed homogeneous distribution in these plants, and they do not fill properly. The factors limiting grain filling of such spikelets, especially in the lower panicle branches, are elusive. Two long-duration rice cultivars differing in panicle density, Mahalaxmi (compact and Upahar (lax were cultivated in an open field plot. Grain filling, ethylene production and constitutive expression of ethylene receptors and ethylene signal transducers in apical and basal spikelets of the panicle were compared during the early post-anthesis stage, which is the most critical period for grain development. In another experiment, a similar assessment was made for the medium-duration cultivars compact-panicle OR-1918 and lax-panicle Lalat. Grain weight of the apical spikelets was always higher than that of the basal spikelets. This gradient of grain weight was wide in the compact-panicle cultivars and narrow in the lax-panicle cultivars. Compared to apical spikelets, the basal spikelets produced more ethylene at anthesis and retained the capacity for post-anthesis expression of ethylene receptors and ethylene signal transducers longer. High ethylene production enhanced the expression of the RSR1 gene, but reduced expression of the GBSS1 gene. Ethylene inhibited the partitioning of assimilates of developing grains resulting in low starch biosynthesis and high accumulation of soluble carbohydrates. It is concluded that an increase in grain/spikelet density in rice panicles reduces apical dominance to the detriment of grain filling by production of ethylene and/or enhanced perception of the ethylene signal. Ethylene could be a second messenger for apical dominance in grain filling. The manipulation of the ethylene signal would possibly improve rice grain yield.

  15. Constitutively elevated salicylic acid levels alter photosynthesis and oxidative state but not growth in transgenic populus.

    Science.gov (United States)

    Xue, Liang-Jiao; Guo, Wenbing; Yuan, Yinan; Anino, Edward O; Nyamdari, Batbayar; Wilson, Mark C; Frost, Christopher J; Chen, Han-Yi; Babst, Benjamin A; Harding, Scott A; Tsai, Chung-Jui

    2013-07-01

    Salicylic acid (SA) has long been implicated in plant responses to oxidative stress. SA overproduction in Arabidopsis thaliana leads to dwarfism, making in planta assessment of SA effects difficult in this model system. We report that transgenic Populus tremula × alba expressing a bacterial SA synthase hyperaccumulated SA and SA conjugates without negative growth consequences. In the absence of stress, endogenously elevated SA elicited widespread metabolic and transcriptional changes that resembled those of wild-type plants exposed to oxidative stress-promoting heat treatments. Potential signaling and oxidative stress markers azelaic and gluconic acids as well as antioxidant chlorogenic acids were strongly coregulated with SA, while soluble sugars and other phenylpropanoids were inversely correlated. Photosynthetic responses to heat were attenuated in SA-overproducing plants. Network analysis identified potential drivers of SA-mediated transcriptome rewiring, including receptor-like kinases and WRKY transcription factors. Orthologs of Arabidopsis SA signaling components NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 and thioredoxins were not represented. However, all members of the expanded Populus nucleoredoxin-1 family exhibited increased expression and increased network connectivity in SA-overproducing Populus, suggesting a previously undescribed role in SA-mediated redox regulation. The SA response in Populus involved a reprogramming of carbon uptake and partitioning during stress that is compatible with constitutive chemical defense and sustained growth, contrasting with the SA response in Arabidopsis, which is transient and compromises growth if sustained.

  16. Moss Pathogenesis-Related-10 protein enhances resistance to Pythium irregulare in Physcomitrella patens and Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Alexandra eCastro

    2016-04-01

    Full Text Available Plants respond to pathogen infection by activating signaling pathways leading to the accumulation of proteins with diverse roles in defense. Here, we addressed the functional role of PpPR-10, a pathogenesis-related (PR-10 gene, of the moss Physcomitrella patens, in response to biotic stress. PpPR-10 belongs to a multigene family and encodes a protein twice the usual size of PR-10 proteins due to the presence of two Bet v1 domains. Moss PR-10 genes are differentially regulated during development and inoculation with the fungal pathogen Botrytis cinerea. Specifically, PpPR-10 transcript levels increase significantly by treatments with elicitors of Pectobacterium carotovorum subsp. carotovorum, spores of B. cinerea, and the defense hormone salicylic acid. To characterize the role of PpPR-10 in plant defense against pathogens, we conducted overexpression analysis in P. patens and in Arabidopsis thaliana. We demonstrate that constitutive expression of PpPR-10 in moss tissues increased resistance against the oomycete Pythium irregulare. PpPR-10 overexpressing moss plants developed less symptoms and decreased mycelium growth than wild type plants. In addition, PpPR-10 overexpressing plants constitutively produced cell wall depositions in protonemal tissue. Ectopic expression of PpPR-10 in Arabidopsis resulted in increased resistance against P. irregulare as well, evidenced by smaller lesions and less cellular damage compared to wild type plants. These results indicate that PpPR-10 is functionally active in the defense against the pathogen P. irregulare, in both P. patens and Arabidopsis, two evolutionary distant plants. Thus, P. patens can serve as an interesting source of genes to improve resistance against pathogen infection in flowering plants.

  17. Computational analysis and low-scale constitutive expression of laccases synthetic genes GlLCC1 from Ganoderma lucidum and POXA 1B from Pleurotus ostreatus in Pichia pastoris.

    Directory of Open Access Journals (Sweden)

    Claudia M Rivera-Hoyos

    Full Text Available Lacasses are multicopper oxidases that can catalyze aromatic and non-aromatic compounds concomitantly with reduction of molecular oxygen to water. Fungal laccases have generated a growing interest due to their biotechnological potential applications, such as lignocellulosic material delignification, biopulping and biobleaching, wastewater treatment, and transformation of toxic organic pollutants. In this work we selected fungal genes encoding for laccase enzymes GlLCC1 in Ganoderma lucidum and POXA 1B in Pleurotus ostreatus. These genes were optimized for codon use, GC content, and regions generating secondary structures. Laccase proposed computational models, and their interaction with ABTS [2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid] substrate was evaluated by molecular docking. Synthetic genes were cloned under the control of Pichia pastoris glyceraldehyde-3-phosphate dehydrogenase (GAP constitutive promoter. P. pastoris X-33 was transformed with pGAPZαA-LaccGluc-Stop and pGAPZαA-LaccPost-Stop constructs. Optimization reduced GC content by 47 and 49% for LaccGluc-Stop and LaccPost-Stop genes, respectively. A codon adaptation index of 0.84 was obtained for both genes. 3D structure analysis using SuperPose revealed LaccGluc-Stop is similar to the laccase crystallographic structure 1GYC of Trametes versicolor. Interaction analysis of the 3D models validated through ABTS, demonstrated higher substrate affinity for LaccPost-Stop, in agreement with our experimental results with enzymatic activities of 451.08 ± 6.46 UL-1 compared to activities of 0.13 ± 0.028 UL-1 for LaccGluc-Stop. This study demonstrated that G. lucidum GlLCC1 and P. ostreatus POXA 1B gene optimization resulted in constitutive gene expression under GAP promoter and α-factor leader in P. pastoris. These are important findings in light of recombinant enzyme expression system utility for environmentally friendly designed expression systems, because of the wide range

  18. Crushed Salt Constitutive Model

    International Nuclear Information System (INIS)

    Callahan, G.D.

    1999-01-01

    The constitutive model used to describe the deformation of crushed salt is presented in this report. Two mechanisms -- dislocation creep and grain boundary diffusional pressure solution -- are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. Upon complete consolidation, the crushed-salt model reproduces the Multimechanism Deformation (M-D) model typically used for the Waste Isolation Pilot Plant (WIPP) host geological formation salt. New shear consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on WIPP and southeastern New Mexico salt. Nonlinear least-squares model fitting to the database produced two sets of material parameter values for the model -- one for the shear consolidation tests and one for a combination of the shear and hydrostatic consolidation tests. Using the parameter values determined from the fitted database, the constitutive model is validated against constant strain-rate tests. Shaft seal problems are analyzed to demonstrate model-predicted consolidation of the shaft seal crushed-salt component. Based on the fitting statistics, the ability of the model to predict the test data, and the ability of the model to predict load paths and test data outside of the fitted database, the model appears to capture the creep consolidation behavior of crushed salt reasonably well

  19. Communicative Constitution of Organizations

    DEFF Research Database (Denmark)

    Schoeneborn, Dennis; Vasquez, Consuelo

    2017-01-01

    The notion of the communicative constitution of organizations (CCO) is at the center of a growing theoretical development within organizational communication studies. CCO scholarship is based on the idea that organization emerges in and is sustained and transformed by communication. This entry...

  20. Gender and the Constitution

    Science.gov (United States)

    Ginsburg, Ruth Bader

    1975-01-01

    In discussing the constitutional aspects of the sex-role debate in the U.S. the author traces the tradition, compares the present criterion of equal protection to the equal rights argument, and analyzes the equality principle with reference to affirmative action and to childbearing and childrearing, supporting the proposed equal rights amendment.…

  1. constitutional adjudication in ethiopia

    African Journals Online (AJOL)

    eliasn

    2000-01-25

    Jan 25, 2000 ... Thus the seeds of what some authors call. “federal .... Pre-WWII Europe trusted its legislature and led to .... European and Civil Law Forum v. 11 ...... on the sovereignty of nationalities and the fact that language constitutes one.

  2. The constitutive sofa cushion

    DEFF Research Database (Denmark)

    Hanghøj, Sara

    2009-01-01

    personal values materialize through a hand-made everyday artefact, and how can the artefact constitute action and self-perception? The empirical research and analysis concerns how a former textile crafts teacher's subjective values and professional identity materialize through a hand-woven sofa cushion...

  3. A Prospect and Challenges for Adopting Constitutional Complaint and Constitutional Question in the Indonesian Constitutional Court

    OpenAIRE

    Faiz, Pan Mohamad

    2016-01-01

    A jurisdiction of the Indonesian Constitutional Court concerning constitutional adjudication is only limited to review the constitutionality of national law. There is no mechanism for challenging any decision or action made by public authorities that violate fundamental rights enshrined in the Indonesian Constitution. This article argues that constitutional complaint and constitutional question might be adopted as new jurisdictions of the Indonesian Constitutional Court in order to strengthen...

  4. Single-cell and coupled GRN models of cell patterning in the Arabidopsis thaliana root stem cell niche

    Directory of Open Access Journals (Sweden)

    Alvarez-Buylla Elena R

    2010-10-01

    Full Text Available Abstract Background Recent experimental work has uncovered some of the genetic components required to maintain the Arabidopsis thaliana root stem cell niche (SCN and its structure. Two main pathways are involved. One pathway depends on the genes SHORTROOT and SCARECROW and the other depends on the PLETHORA genes, which have been proposed to constitute the auxin readouts. Recent evidence suggests that a regulatory circuit, composed of WOX5 and CLE40, also contributes to the SCN maintenance. Yet, we still do not understand how the niche is dynamically maintained and patterned or if the uncovered molecular components are sufficient to recover the observed gene expression configurations that characterize the cell types within the root SCN. Mathematical and computational tools have proven useful in understanding the dynamics of cell differentiation. Hence, to further explore root SCN patterning, we integrated available experimental data into dynamic Gene Regulatory Network (GRN models and addressed if these are sufficient to attain observed gene expression configurations in the root SCN in a robust and autonomous manner. Results We found that an SCN GRN model based only on experimental data did not reproduce the configurations observed within the root SCN. We developed several alternative GRN models that recover these expected stable gene configurations. Such models incorporate a few additional components and interactions in addition to those that have been uncovered. The recovered configurations are stable to perturbations, and the models are able to recover the observed gene expression profiles of almost all the mutants described so far. However, the robustness of the postulated GRNs is not as high as that of other previously studied networks. Conclusions These models are the first published approximations for a dynamic mechanism of the A. thaliana root SCN cellular pattering. Our model is useful to formally show that the data now available are not

  5. Comparative evolution history of SINEs in Arabidopsis thaliana and Brassica oleracea: evidence for a high rate of SINE loss.

    Science.gov (United States)

    Lenoir, A; Pélissier, T; Bousquet-Antonelli, C; Deragon, J M

    2005-01-01

    Brassica oleracea and Arabidopsis thaliana belong to the Brassicaceae(Cruciferae) family and diverged 16 to 19 million years ago. Although the genome size of B. oleracea (approximately 600 million base pairs) is more than four times that of A. thaliana (approximately 130 million base pairs), their gene content is believed to be very similar with more than 85% sequence identity in the coding region. Therefore, this important difference in genome size is likely to reflect a different rate of non-coding DNA accumulation. Transposable elements (TEs) constitute a major fraction of non-coding DNA in plant species. A different rate in TE accumulation between two closely related species can result in significant genome size variations in a short evolutionary period. Short interspersed elements (SINEs) are non-autonomous retroposons that have invaded the genome of most eukaryote species. Several SINE families are present in B. oleracea and A. thaliana and we found that two of them (called RathE1 and RathE2) are present in both species. In this study, the tempo of evolution of RathE1 and RathE2 SINE families in both species was compared. We observed that most B. oleracea RathE2 SINEs are "young" (close to the consensus sequence) and abundant while elements from this family are more degenerated and much less abundant in A. thaliana. However, the situation is different for the RathE1 SINE family for which the youngest elements are found in A. thaliana. Surprisingly, no SINE was found to occupy the same (orthologous) genomic locus in both species suggesting that either these SINE families were not amplified at a significant rate in the common ancestor of the two species or that older elements were lost and only the recent (lineage-specific) insertions remain. To test this latter hypothesis, loci containing a recently inserted SINE in the A. thaliana col-0 ecotype were selected and characterized in several other A. thaliana ecotypes. In addition to the expected SINE containing

  6. Light-grown plants of transgenic tobacco expressing an introduced oat phytochrome A gene under the control of a constitutive viral promoter exhibit persistent growth inhibition by far-red light

    International Nuclear Information System (INIS)

    McCormac, A.; Whitelam, G.; Smith, H.

    1992-01-01

    A comparison of the photoregulation of development has been made for etiolated and light-grown plants of wild-type (WT) tobacco (Nicotiana tabacun L.) and an isogenic transgenic line which expresses an introduced oat phytochrome gene (phyA) under the control of a constitutive viral promoter. Etiolated seedlings of both the WT and transgenic line showed irradiance-dependent inhibition of hypocotyl growth under continuous far-red (FR) light; transgenic seedlings showed a greater level of inhibition under a given fluence rate and this is considered to be the result of the heterologous phytochrome protein (PhyA) functioning in a compatible manner with the native etiolated phytochrome. Deetiolation of WT seedlings resulted in a loss of responsiveness to prolonged FR. Light-grown transgenic seedlings, however, continued to respond in an irradiance-dependent manner to prolonged FR and it is proposed that this is a specific function of the constitutive PhyA. Mature green plants of the WT and transgenic lines showed a qualitatively similar growth promotion to a brief end-of-day FR-treatment but this response was abolished in the transgenic plants under prolonged irradiation by this same FR source. Growth inhibition (McCormac et al. 1991, Planta 185, 162-170) and enhanced levels of nitrate-reductase activity under irradiance of low red:far-red ratio, as achieved by the FR-supplementation of white light, emphasised that the introduced PhyA was eliciting an aberrant mode of photoresponse compared with the normal phytochrome population of light-grown plants. Total levels of the oat-encoded phytochrome in the etiolated transgenic tobacco were shown to be influenced by the wavelength of continuous irradiation in a manner which was qualitatively similar to that seen for the native, etiolated tobacco phytochrome, and distinct from that seen in etiolated oat tissues. These results are discussed in terms of the proposal that the constitutive oat-PhyA pool in the transgenic plants

  7. Use of the "gl1" Mutant and the "CA-rop2" Transgenic Plants of "Arabidopsis thaliana" in the Biology Laboratory Course

    Science.gov (United States)

    Zheng, Zhi-Liang

    2006-01-01

    This article describes the use of the "glabrous1 (g11)" mutant and constitutively active "(CA)-rop2" transgenic plants of "Arabidopsis thaliana" in teaching genetics laboratory for both high school and undergraduate students. The experiments provide students with F[subscript 1] and F[subscript 2] generations within a semester for genetic and…

  8. Sinapic acid or its derivatives interfere with abscisic acid homeostasis during Arabidopsis thaliana seed germination.

    Science.gov (United States)

    Bi, Baodi; Tang, Jingliang; Han, Shuang; Guo, Jinggong; Miao, Yuchen

    2017-06-06

    Sinapic acid and its esters have broad functions in different stages of seed germination and plant development and are thought to play a role in protecting against ultraviolet irradiation. To better understand the interactions between sinapic acid esters and seed germination processes in response to various stresses, we analyzed the role of the plant hormone abscisic acid (ABA) in the regulation of sinapic acid esters involved in seed germination and early seedling growth. We found that exogenous sinapic acid promotes seed germination in a dose-dependent manner in Arabidopsis thaliana. High-performance liquid chromatography mass spectrometry analysis showed that exogenous sinapic acid increased the sinapoylcholine content of imbibed seeds. Furthermore, sinapic acid affected ABA catabolism, resulting in reduced ABA levels and increased levels of the ABA-glucose ester. Using mutants deficient in the synthesis of sinapate esters, we showed that the germination of mutant sinapoylglucose accumulator 2 (sng2) and bright trichomes 1 (brt1) seeds was more sensitive to ABA than the wild-type. Moreover, Arabidopsis mutants deficient in either abscisic acid deficient 2 (ABA2) or abscisic acid insensitive 3 (ABI3) displayed increased expression of the sinapoylglucose:choline sinapoyltransferase (SCT) and sinapoylcholine esterase (SCE) genes with sinapic acid treatment. This treatment also affected the accumulation of sinapoylcholine and free choline during seed germination. We demonstrated that sinapoylcholine, which constitutes the major phenolic component in seeds among various minor sinapate esters, affected ABA homeostasis during seed germination and early seedling growth in Arabidopsis. Our findings provide insights into the role of sinapic acid and its esters in regulating ABA-mediated inhibition of Arabidopsis seed germination in response to drought stress.

  9. Arabidopsis thaliana cdd1 mutant uncouples the constitutive activation of salicylic acid signalling from growth defects

    NARCIS (Netherlands)

    Swain, S.; Roy, S.; Shah, J.; Wees, S.C.M. van; Pieterse, C.M.J.; Nandi, A.K.

    2011-01-01

    Arabidopsis genotypes with a hyperactive salicylic acidmediated signalling pathway exhibit enhanced disease resistance, which is often coupled with growth and developmental defects, such as dwarfing and spontaneous necrotic lesions on the leaves, resulting in reduced biomass yield. In this article,

  10. What constitutes information integrity?

    Directory of Open Access Journals (Sweden)

    S. Flowerday

    2008-01-01

    Full Text Available This research focused on what constitutes information integrity as this is a problem facing companies today. Moreover, information integrity is a pillar of information security and is required in order to have a sound security management programme. However, it is acknowledged that 100% information integrity is not currently achievable due to various limitations and therefore the auditing concept of reasonable assurance is adopted. This is in line with the concept that 100% information security is not achievable and the notion that adequate security is the goal, using appropriate countermeasures. The main contribution of this article is to illustrate the importance of and provide a macro view of what constitutes information integrity. The findings are in harmony with Samuel Johnson's words (1751: 'Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.'

  11. What constitutes information integrity?

    Directory of Open Access Journals (Sweden)

    S. Flowerday

    2007-12-01

    Full Text Available This research focused on what constitutes information integrity as this is a problem facing companies today. Moreover, information integrity is a pillar of information security and is required in order to have a sound security management programme. However, it is acknowledged that 100% information integrity is not currently achievable due to various limitations and therefore the auditing concept of reasonable assurance is adopted. This is in line with the concept that 100% information security is not achievable and the notion that adequate security is the goal, using appropriate countermeasures. The main contribution of this article is to illustrate the importance of and provide a macro view of what constitutes information integrity. The findings are in harmony with Samuel Johnson's words (1751: 'Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.'

  12. The constitutional view

    Directory of Open Access Journals (Sweden)

    Roberto Horácio Sá Pereira

    2016-05-01

    Full Text Available http://dx.doi.org/10.5007/1808-1711.2016v20n2p165   This brief paper is devoted to criticizing the widespread reading of Kant’s first Critique, according to which reference to subject-independent objects is “constituted” by higherorder cognitive abilities (concepts. Let us call this the “constitutional view”. In this paper, I argue that the constitutional reading confuses the un-Kantian problem of how we come to represent objects (which I call the intentionality thesis, with the quite different problem of how we cognize (erkennen (which I call the “cognition thesis” that we do represent objects, that is, things that exist independently of the subject.

  13. Transnational Governance and Constitutionalism

    DEFF Research Database (Denmark)

    Joerges, Christian; Sand, Inger-Johanne; Teubner, Gunther

    of democratic governance. The book refers to this term as a yardstick to which then contributors feel committed even where they plead for a reconceptualisation of constitutionalism or a discussion of its functional equivalents. 'Transnational governance' is neither public nor private, nor purely international......The term transnational governance designates untraditional types of international and regional collaboration among both public and private actors. These legally-structured or less formal arrangements link economic, scientific and technological spheres with political and legal processes...

  14. Characterization and Ectopic Expression of CoWRI1, an AP2/EREBP Domain-Containing Transcription Factor from Coconut (Cocos nucifera L.) Endosperm, Changes the Seeds Oil Content in Transgenic Arabidopsis thaliana and Rice (Oryza sativa L.).

    Science.gov (United States)

    Sun, RuHao; Ye, Rongjian; Gao, Lingchao; Zhang, Lin; Wang, Rui; Mao, Ting; Zheng, Yusheng; Li, Dongdong; Lin, Yongjun

    2017-01-01

    Coconut ( Cocos nucifera L.) is a key tropical crop and a member of the monocotyledonous family Arecaceae ( Palmaceae ). Few genes and related metabolic processes involved in coconut endosperm development have been investigated. In this study, a new member of the WRI1 gene family was isolated from coconut endosperm and was named CoWRI1 . Its transcriptional activities and interactions with the acetyl-CoA carboxylase ( BCCP2 ) promoter of CoWRI1 were confirmed by the yeast two-hybrid and yeast one-hybrid approaches, respectively. Functional characterization was carried out through seed-specific expression in Arabidopsis and endosperm-specific expression in rice. In transgenic Arabidopsis , high over-expressions of CoWRI1 in seven independent T2 lines were detected by quantitative real-time PCR. The relative mRNA accumulation of genes encoding enzymes involved in either fatty acid biosynthesis or triacylglycerols assembly (BCCP2, KASI, MAT, ENR, FATA, and GPDH) were also assayed in mature seeds. Furthermore, lipid and fatty acids C16:0 and C18:0 significantly increased. In two homozygous T2 transgenic rice lines (G5 and G2), different CoWRI1 expression levels were detected, but no CoWRI1 transcripts were detected in the wild type. Analyses of the seed oil content, starch content, and total protein content indicated that the two T2 transgenic lines showed a significant increase ( P oil content. The transgenic lines also showed a significant increase in starch content, whereas total protein content decreased significantly. Further analysis of the fatty acid composition revealed that palmitic acid (C16:0) and linolenic acid (C18:3) increased significantly in the seeds of the transgenic rice lines, but oleic acid (C18:1) levels significantly declined.

  15. Early transcriptomic changes induced by magnesium deficiency in Arabidopsis thaliana reveal the alteration of circadian clock gene expression in roots and the triggering of abscisic acid-responsive genes.

    Science.gov (United States)

    Hermans, Christian; Vuylsteke, Marnik; Coppens, Frederik; Craciun, Adrian; Inzé, Dirk; Verbruggen, Nathalie

    2010-07-01

    *Plant growth and development ultimately depend on environmental variables such as the availability of essential minerals. Unravelling how nutrients affect gene expression will help to understand how they regulate plant growth. *This study reports the early transcriptomic response to magnesium (Mg) deprivation in Arabidopsis. Whole-genome transcriptome was studied in the roots and young mature leaves 4, 8 and 28 h after the removal of Mg from the nutrient solution. *The highest number of regulated genes was first observed in the roots. Contrary to other mineral deficiencies, Mg depletion did not induce a higher expression of annotated genes in Mg uptake. Remarkable responses include the perturbation of the central oscillator of the circadian clock in roots and the triggering of abscisic acid (ABA) signalling, with half of the up-regulated Mg genes in leaves being ABA-responsive. However, no change in ABA content was observed. *The specificity of the response of some Mg-regulated genes was challenged by studying their expression after other mineral deficiencies and environmental stresses. The possibility to develop markers for Mg incipient deficiency is discussed here.

  16. The pattern of polymorphism in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available We resequenced 876 short fragments in a sample of 96 individuals of Arabidopsis thaliana that included stock center accessions as well as a hierarchical sample from natural populations. Although A. thaliana is a selfing weed, the pattern of polymorphism in general agrees with what is expected for a widely distributed, sexually reproducing species. Linkage disequilibrium decays rapidly, within 50 kb. Variation is shared worldwide, although population structure and isolation by distance are evident. The data fail to fit standard neutral models in several ways. There is a genome-wide excess of rare alleles, at least partially due to selection. There is too much variation between genomic regions in the level of polymorphism. The local level of polymorphism is negatively correlated with gene density and positively correlated with segmental duplications. Because the data do not fit theoretical null distributions, attempts to infer natural selection from polymorphism data will require genome-wide surveys of polymorphism in order to identify anomalous regions. Despite this, our data support the utility of A. thaliana as a model for evolutionary functional genomics.

  17. Molecular cloning of a seed specific multifunctional RFO synthase/ galactosylhydrolase in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Roman eGangl

    2015-09-01

    Full Text Available Stachyose is among the raffinose family oligosaccharides one of the major water-soluble carbohydrates next to sucrose in seeds of a number of plant species. Especially in leguminous seeds, e.g. chickpea, stachyose is reported as the major component. In contrast to their ambiguous potential as essential source of carbon for germination, raffinose family oligosaccharides are indigestible for humans and can contribute to diverse abdominal disorders.In the genome of Arabidopsis thaliana, six putative raffinose synthase genes are reported, whereas little is known about these putative raffinose synthases and their biochemical characteristics or their contribution to the raffinose family oligosaccharide physiology in A. thaliana.In this paper, we report on the molecular cloning, functional expression in Escherichia coli and purification of recombinant AtRS4 from A. thaliana and the biochemical characterisation of the putative stachyose synthase (AtSTS, At4g01970 as a raffinose and high affinity stachyose synthase (Km for raffinose 259.2 ± 21.15 µM as well as stachyose and galactinol specific galactosylhydrolase. A T-DNA insertional mutant in the AtRS4 gene was isolated. Only sqPCR from WT siliques showed a specific transcriptional AtRS4 PCR product. Metabolite measurements in seeds of ΔAtRS4 mutant plants revealed a total loss of stachyose in ΔAtRS4 mutant seeds. We conclude that AtRS4 is the only stachyose synthase in the genome of A. thaliana that AtRS4 represents a key regulation mechanism in the raffinose family oligosaccharide physiology of A. thaliana due to its multifunctional enzyme activity and that AtRS4 is possibly the second seed specific raffinose synthase beside AtRS5, which is responsible for Raf-accumulation under abiotic stress.

  18. Human Norovirus and Its Surrogates Induce Plant Immune Response in Arabidopsis thaliana and Lactuca sativa.

    Science.gov (United States)

    Markland, Sarah M; Bais, Harsh; Kniel, Kalmia E

    2017-08-01

    Human norovirus is the leading cause of foodborne illness worldwide with the majority of outbreaks linked to fresh produce and leafy greens. It is essential that we thoroughly understand the type of relationship and interactions that take place between plants and human norovirus to better utilize control strategies to reduce transmission of norovirus in the field onto plants harvested for human consumption. In this study the expression of gene markers for the salicylic acid (SA) and jasmonic acid (JA) plant defense pathways was measured and compared in romaine lettuce (Lactuca sativa) and Arabidopsis thaliana Col-0 plants that were inoculated with Murine Norovirus-1, Tulane Virus, human norovirus GII.4, or Hank's Balanced Salt Solution (control). Genes involving both the SA and JA pathways were expressed in both romaine lettuce and A. thaliana for all three viruses, as well as controls. Studies, including gene expression of SA- and JA-deficient A. thaliana mutant lines, suggest that the JA pathway is more likely involved in the plant immune response to human norovirus. This research provides the first pieces of information regarding how foodborne viruses interact with plants in the preharvest environment.

  19. Genome-wide comparative analysis of NBS-encoding genes between Brassica species and Arabidopsis thaliana.

    Science.gov (United States)

    Yu, Jingyin; Tehrim, Sadia; Zhang, Fengqi; Tong, Chaobo; Huang, Junyan; Cheng, Xiaohui; Dong, Caihua; Zhou, Yanqiu; Qin, Rui; Hua, Wei; Liu, Shengyi

    2014-01-03

    Plant disease resistance (R) genes with the nucleotide binding site (NBS) play an important role in offering resistance to pathogens. The availability of complete genome sequences of Brassica oleracea and Brassica rapa provides an important opportunity for researchers to identify and characterize NBS-encoding R genes in Brassica species and to compare with analogues in Arabidopsis thaliana based on a comparative genomics approach. However, little is known about the evolutionary fate of NBS-encoding genes in the Brassica lineage after split from A. thaliana. Here we present genome-wide analysis of NBS-encoding genes in B. oleracea, B. rapa and A. thaliana. Through the employment of HMM search and manual curation, we identified 157, 206 and 167 NBS-encoding genes in B. oleracea, B. rapa and A. thaliana genomes, respectively. Phylogenetic analysis among 3 species classified NBS-encoding genes into 6 subgroups. Tandem duplication and whole genome triplication (WGT) analyses revealed that after WGT of the Brassica ancestor, NBS-encoding homologous gene pairs on triplicated regions in Brassica ancestor were deleted or lost quickly, but NBS-encoding genes in Brassica species experienced species-specific gene amplification by tandem duplication after divergence of B. rapa and B. oleracea. Expression profiling of NBS-encoding orthologous gene pairs indicated the differential expression pattern of retained orthologous gene copies in B. oleracea and B. rapa. Furthermore, evolutionary analysis of CNL type NBS-encoding orthologous gene pairs among 3 species suggested that orthologous genes in B. rapa species have undergone stronger negative selection than those in B .oleracea species. But for TNL type, there are no significant differences in the orthologous gene pairs between the two species. This study is first identification and characterization of NBS-encoding genes in B. rapa and B. oleracea based on whole genome sequences. Through tandem duplication and whole genome

  20. Atypical DNA methylation of genes encoding cysteine-rich peptides in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    You Wanhui

    2012-04-01

    Full Text Available Abstract Background In plants, transposons and non-protein-coding repeats are epigenetically silenced by CG and non-CG methylation. This pattern of methylation is mediated in part by small RNAs and two specialized RNA polymerases, termed Pol IV and Pol V, in a process called RNA-directed DNA methylation. By contrast, many protein-coding genes transcribed by Pol II contain in their gene bodies exclusively CG methylation that is independent of small RNAs and Pol IV/Pol V activities. It is unclear how the different methylation machineries distinguish between transposons and genes. Here we report on a group of atypical genes that display in their coding region a transposon-like methylation pattern, which is associated with gene silencing in sporophytic tissues. Results We performed a methylation-sensitive amplification polymorphism analysis to search for targets of RNA-directed DNA methylation in Arabidopsis thaliana and identified several members of a gene family encoding cysteine-rich peptides (CRPs. In leaves, the CRP genes are silent and their coding regions contain dense, transposon-like methylation in CG, CHG and CHH contexts, which depends partly on the Pol IV/Pol V pathway and small RNAs. Methylation in the coding region is reduced, however, in the synergid cells of the female gametophyte, where the CRP genes are specifically expressed. Further demonstrating that expressed CRP genes lack gene body methylation, a CRP4-GFP fusion gene under the control of the constitutive 35 S promoter remains unmethylated in leaves and is transcribed to produce a translatable mRNA. By contrast, a CRP4-GFP fusion gene under the control of a CRP4 promoter fragment acquires CG and non-CG methylation in the CRP coding region in leaves similar to the silent endogenous CRP4 gene. Conclusions Unlike CG methylation in gene bodies, which does not dramatically affect Pol II transcription, combined CG and non-CG methylation in CRP coding regions is likely to

  1. Isolation and characterization of CNGC17 gene from Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Yamagami, Mutsumi; Kobayashi, Daisuke; Hisamatsu, Shun'ichi

    2007-01-01

    Phytoremediation is a possible countermeasure for cleaning up soil contaminated by 137 Cs, and development of plants which can effectively absorb 137 Cs is important for it. It is expected that capability of Cs extraction from soil can be strengthened by genetic alteration of the Cs + root-uptake mechanism of plants. This study aimed at elucidating the uptake mechanism of Cs + for future genetic engineering. Plant roots take up Cs + from the soil solution via transport proteins at the plasma membrane of root cells. Voltage-insensitive cation channels (VICCs) are a possible transfer route of Cs + , and they are encoded by cyclic-nucleotide gated channel (CNGC) and glutamate receptor (GLR) gene families. The genome of Arabidopsis thaliana contains 20 CNGC genes. We have cloned a putative AtCNGC17 gene from cDNAs which were generated with total-RNA obtained from leaves of Arabidopsis thaliana by RT-PCR. The cDNA contained 2163 bp with an ORF that encoded a protein consisting of 721 amino acids residues. The plasmid prepared by the insertion of the gene under a Taq promoter was used to transform an E. coli deficient in the three major K + uptake systems (Kdp, Trk, and Kup). Only the E. coli with AtCNGC17 gene grew in low K + concentration minimal medium. This result suggested that the AtCNGC17 protein has a function of K + uptake. Growth rates of the E. coli cells expressing the gene were strongly inhibited by CsCl in low K + concentration minimal medium, suggesting that the AtCNGC17 transporter also carries Cs + . (author)

  2. Distinct modes of adventitious rooting in Arabidopsis thaliana.

    Science.gov (United States)

    Correa, L da Rocha; Troleis, J; Mastroberti, A A; Mariath, J E A; Fett-Neto, A G

    2012-01-01

    The literature describes different rooting protocols for Arabidopsis thaliana as models to study adventitious rooting, and results are generally perceived as comparable. However, there is a lack of investigations focusing on the distinct features, advantages and limitations of each method in the study of adventitious rooting with both wild-type (WT) ecotypes and their respective mutants. This investigation was undertaken to evaluate the adventitious rooting process in three different experimental systems, all using A. thaliana, analysing the same rooting parameters after transient exposure to auxin (indole-3-acetic acid) and control conditions: excised leaves, de-rooted plants and etiolated seedlings. The founding tissues and sites of origin of roots differed depending on the system used, whereas all rooting patterns were of the direct type (i.e., without callus formation). None of the systems had an absolute requirement for exogenous auxin, although rooting was enhanced by this phytohormone, with the exception of de-rooted plants, which had adventitious rooting strongly inhibited by exogenous auxin. Root elongation was much favoured in isolated leaves. Auxin-overproducing mutants could not be used in the detached leaf system due to precocious senescence; in the de-rooted plant system, these mutants had a WT-like rooting response, whereas the expression of the 'rooty' phenotype was only evident in the etiolated seedling system. Adventitious rooting of etiolated WT seedlings in the presence of exogenous auxin was inhibited by exogenous flavonoids, which act as auxin transport inhibitors; surprisingly, the flavonoid-deficient mutant chs had a lower rooting response compared to WT. Although Arabidopsis is an excellent model system to study adventitious rooting, physiological and developmental responses differed significantly, underlining the importance of avoiding data generalisation on rooting responses derived from different experimental systems with this species.

  3. Constitution, 5 May 1989.

    Science.gov (United States)

    1989-01-01

    This document contains provisions of Cambodia's Constitution of May 5, 1989. Article 7 gives men and women equal rights in marriage and the family, calls for monogamous marriages, and affords social protection to mothers and children. Article 8 guides parent-child relationships. The 14th article defines state property, and the 15th gives citizens full rights to own, use, and inherit land. The use of agricultural and forested land can only be changed with permission. Article 22 assigns educational responsibilities to the state, including free elementary education and a gradual expansion of higher education. Adult literacy classes are also promoted. Article 26 guarantees free medical consultations, and article 27 gives women a 90-day paid maternity leave. Breast-feeding women are also given special privileges. Article 33 guarantees the right to pay equity and to social security benefits. Article 36 grants the freedom to travel, the inviolability of homes, and privacy in correspondence of all types.

  4. Constitution, 5 October 1988.

    Science.gov (United States)

    1989-01-01

    This document contains major provisions of the constitution adopted by Brazil on 5 October 1988. This constitution seeks to promote the welfare of all citizens without discrimination. The equality of all citizens is guaranteed, and the equal rights of women are specifically mentioned. Property rights are also guaranteed and defined. Female inmates are granted the right to remain with their children while breast feeding. Workers are guaranteed a minimum wage, a family allowance for dependents, maternity/paternity leave, specific incentives to protect the labor market for women, retirement benefits, free day care for preschool-age children, pay equity, and equal rights between tenured and sporadically employed workers. Agrarian reform provisions are given, including the authority to expropriate land. Social and economic policies to promote health are called for, and public health services are to be decentralized, to be integrated, and to foster community participation. Pension plan and social assistance provisions are outlined as are duties of the state in regard to education. The amount of money to be dedicated to education is set out, and a national educational plan is called for to achieve such goals as the eradication of illiteracy, the universalization of school attendance, the improvement of instruction, and the provision of vocational training. Specific measures are set out to protect and preserve the environment. Family policy deals with issues of marriage, the definition of a family, divorce, the right to family planning services, and the deterrence of domestic violence. Social protection provisions cover mothers and children, handicapped persons, and protection of minors. Finally, the customs and rights of Indians are protected, with special provisions given to protect land tenure and to protect the rights of Indians in water resource development and prospecting and mining activities.

  5. Genetic analysis of seed development in Arabidopsis thaliana = [Genetische analyse van de zaadontwikkeling in Arabidopsis thaliana

    NARCIS (Netherlands)

    Leon - Kloosterziel, K.

    1997-01-01


    This thesis deals with the genetic aspects of seed development in Arabidopsisthaliana. Mutants affected in several aspects of seed development and, more specifically, in seed maturation have been isolated by various selection

  6. Comparison of efficacy of the disease-specific LOX1- and constitutive cytomegalovirus-promoters in expressing interleukin 10 through adeno-associated virus 2/8 delivery in atherosclerotic mice.

    Directory of Open Access Journals (Sweden)

    Hongqing Zhu

    Full Text Available The development of gene therapy vectors for treating diseases of the cardiovascular system continues at a steady pace. Moreover, in the field of gene therapy the utility of "disease-specific promoters" has strong appeal. Many therapeutic genes, including transforming growth factor beta 1 or interleukin 10, are associated to adverse effects. The use of a disease-specific promoter might minimize toxicity. The lectin-like oxidized low density lipoprotein receptor 1 is a marker of cardiovascular disease and a potential therapeutic target. The lectin-like oxidized low density lipoprotein receptor 1 is known to be up-regulated early during disease onset in a number of cell types at the sites where the disease will be clinically evident. In this study an adeno-associated virus-2 DNA vector (AAV2 using the AAV8 capsid, and containing the full length The lectin-like oxidized low density lipoprotein receptor 1 promoter, was generated and assayed for its ability to express human interleukin 10 in low density lipoprotein receptor knockout mice on high cholesterol diet. The cytomegalovirus early promoter was used for comparison in a similarly structured vector. The two promoters were found to have equal efficacy in reducing atherogenesis as measured by aortic systolic blood velocity, aortic cross sectional area, and aortic wall thickness. This is the first head-to-head comparison of a constitutive with a disease-specific promoter in a therapeutic context. These data strongly suggest that the use of a disease-specific promoter is appropriate for therapeutic gene delivery.

  7. Purification, crystallization and preliminary crystallographic analysis of deoxyuridine triphosphate nucleotidohydrolase from Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Bajaj, Mamta; Moriyama, Hideaki

    2007-01-01

    The first crystallization of deoxyuridine triphosphate nucleotidohydrolase from plant, Arabidopsis thaliana, has been performed. An additive, taurine, was effective in producing the single crystal. The deoxyuridine triphosphate nucleotidohydrolase gene from Arabidopsis thaliana was expressed and the gene product was purified. Crystallization was performed by the hanging-drop vapour-diffusion method at 298 K using 2 M ammonium sulfate as the precipitant. X-ray diffraction data were collected to 2.2 Å resolution using Cu Kα radiation. The crystal belongs to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 69.90, b = 70.86 Å, c = 75.55 Å. Assuming the presence of a trimer in the asymmetric unit, the solvent content was 30%, with a V M of 1.8 Å 3 Da −1

  8. Yeast Methylotrophy and Autophagy in a Methanol-Oscillating Environment on Growing Arabidopsis thaliana Leaves

    Science.gov (United States)

    Kawaguchi, Kosuke; Yurimoto, Hiroya; Oku, Masahide; Sakai, Yasuyoshi

    2011-01-01

    The yeast Candida boidinii capable of growth on methanol proliferates and survives on the leaves of Arabidopsis thaliana. The local methanol concentration at the phyllosphere of growing A. thaliana exhibited daily periodicity, and yeast cells responded by altering both the expression of methanol-inducible genes and peroxisome proliferation. Even under these dynamically changing environmental conditions, yeast cells proliferated 3 to 4 times in 11 days. Among the C1-metabolic enzymes, enzymes in the methanol assimilation pathway, but not formaldehyde dissimilation or anti-oxidizing enzymes, were necessary for yeast proliferation at the phyllosphere. Furthermore, both peroxisome assembly and pexophagy, a selective autophagy pathway that degrades peroxisomes, were necessary for phyllospheric proliferation. Thus, the present study sheds light on the life cycle and physiology of yeast in the natural environment at both the molecular and cellular levels. PMID:21966472

  9. Purification, crystallization and preliminary crystallographic analysis of deoxyuridine triphosphate nucleotidohydrolase from Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Bajaj, Mamta [School of Biological Sciences, University of Nebraska-Lincoln, Manter Hall, Lincoln, Nebraska 68588-0304 (United States); Moriyama, Hideaki, E-mail: hmoriyama2@unl.edu [Department of Chemistry, e-Toxicology and Biotechnology, University of Nebraska-Lincoln, Hamilton Hall, Lincoln, Nebraska 68588-0304 (United States); School of Biological Sciences, University of Nebraska-Lincoln, Manter Hall, Lincoln, Nebraska 68588-0304 (United States)

    2007-05-01

    The first crystallization of deoxyuridine triphosphate nucleotidohydrolase from plant, Arabidopsis thaliana, has been performed. An additive, taurine, was effective in producing the single crystal. The deoxyuridine triphosphate nucleotidohydrolase gene from Arabidopsis thaliana was expressed and the gene product was purified. Crystallization was performed by the hanging-drop vapour-diffusion method at 298 K using 2 M ammonium sulfate as the precipitant. X-ray diffraction data were collected to 2.2 Å resolution using Cu Kα radiation. The crystal belongs to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 69.90, b = 70.86 Å, c = 75.55 Å. Assuming the presence of a trimer in the asymmetric unit, the solvent content was 30%, with a V{sub M} of 1.8 Å{sup 3} Da{sup −1}.

  10. Phosphatidic acid is a major phospholipid class in reproductive organs of Arabidopsis thaliana.

    Science.gov (United States)

    Yunus, Ian Sofian; Cazenave-Gassiot, Amaury; Liu, Yu-Chi; Lin, Ying-Chen; Wenk, Markus R; Nakamura, Yuki

    2015-01-01

    Phospholipids are the crucial components of biological membranes and signal transduction. Among different tissues, flower phospholipids are one of the least characterized features of plant lipidome. Here, we report that floral reproductive organs of Arabidopsis thaliana contain high levels of phosphatidic acid (PA), a known lipid second messenger. By using floral homeotic mutants enriched with specific floral organs, lipidomics study showed increased levels of PA species in ap3-3 mutant with enriched pistils. Accompanied gene expression study for 7 diacylglycerol kinases and 11 PA phosphatases revealed distinct floral organ specificity, suggesting an active phosphorylation/dephosphorylation between PA and diacylglycerol in flowers. Our results suggest that PA is a major phospholipid class in floral reproductive organs of A. thaliana.

  11. Crystallization and preliminary X-ray analysis of tubulin-folding cofactor A from Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Lu, Lu; Nan, Jie; Mi, Wei; Wei, Chun-Hong; Li, Lan-Fen; Li, Yi

    2010-01-01

    Tubulin-folding cofactor A from A. thaliana has been crystallized and preliminarily analyzed using X-ray diffraction. Tubulin-folding cofactor A (TFC A) is a molecular post-chaperonin that is involved in the β-tubulin-folding pathway. It has been identified in many organisms including yeasts, humans and plants. In this work, Arabidopsis thaliana TFC A was expressed in Escherichia coli and purified to homogeneity. After thrombin cleavage, a well diffracting crystal was obtained by the sitting-drop vapour-diffusion method at 289 K. The crystal diffracted to 1.6 Å resolution using synchrotron radiation and belonged to space group I4 1 , with unit-cell parameters a = 55.0, b = 55.0, c = 67.4 Å

  12. Alanine aminotransferase variants conferring diverse NUE phenotypes in Arabidopsis thaliana.

    Science.gov (United States)

    McAllister, Chandra H; Good, Allen G

    2015-01-01

    Alanine aminotransferase (AlaAT, E.C. 2.6.1.2), is a pyridoxal-5'-phosphate-dependent (PLP) enzyme that catalyzes the reversible transfer of an amino group from alanine to 2-oxoglutarate to produce glutamate and pyruvate, or vice versa. It has been well documented in both greenhouse and field studies that tissue-specific over-expression of AlaAT from barley (Hordeum vulgare, HvAlaAT) results in a significant increase in plant NUE in both canola and rice. While the physical phenotypes associated with over-expression of HvAlaAT have been well characterized, the role this enzyme plays in vivo to create a more N efficient plant remains unknown. Furthermore, the importance of HvAlaAT, in contrast to other AlaAT enzyme homologues in creating this phenotype has not yet been explored. To address the role of AlaAT in NUE, AlaAT variants from diverse sources and different subcellular locations, were expressed in the wild-type Arabidopsis thaliana Col-0 background and alaat1;2 (alaat1-1;alaat2-1) knockout background in various N environments. The analysis and comparison of both the physical and physiological properties of AlaAT over-expressing transgenic plants demonstrated significant differences between plants expressing the different AlaAT enzymes under different external conditions. This analysis indicates that the over-expression of AlaAT variants other than HvAlaAT in crop plants could further increase the NUE phenotype(s) previously observed.

  13. Ecology of Arabidopsis thaliana : local adaptation and interaction with herbivores

    NARCIS (Netherlands)

    Mosleh Arany, A.

    2006-01-01

    As first step the impact of herbivory and abiotic factors on population dynamics of Arabidopsis thaliana were studied. Ceutorhynchus atomus and C. contractus were identified as the major insect herbivores on A. thaliana population, reducing seed production by more than 40%. Mortality from February

  14. Constitutive models in LAME.

    Energy Technology Data Exchange (ETDEWEB)

    Hammerand, Daniel Carl; Scherzinger, William Mark

    2007-09-01

    The Library of Advanced Materials for Engineering (LAME) provides a common repository for constitutive models that can be used in computational solid mechanics codes. A number of models including both hypoelastic (rate) and hyperelastic (total strain) constitutive forms have been implemented in LAME. The structure and testing of LAME is described in Scherzinger and Hammerand ([3] and [4]). The purpose of the present report is to describe the material models which have already been implemented into LAME. The descriptions are designed to give useful information to both analysts and code developers. Thus far, 33 non-ITAR/non-CRADA protected material models have been incorporated. These include everything from the simple isotropic linear elastic models to a number of elastic-plastic models for metals to models for honeycomb, foams, potting epoxies and rubber. A complete description of each model is outside the scope of the current report. Rather, the aim here is to delineate the properties, state variables, functions, and methods for each model. However, a brief description of some of the constitutive details is provided for a number of the material models. Where appropriate, the SAND reports available for each model have been cited. Many models have state variable aliases for some or all of their state variables. These alias names can be used for outputting desired quantities. The state variable aliases available for results output have been listed in this report. However, not all models use these aliases. For those models, no state variable names are listed. Nevertheless, the number of state variables employed by each model is always given. Currently, there are four possible functions for a material model. This report lists which of these four methods are employed in each material model. As far as analysts are concerned, this information is included only for the awareness purposes. The analyst can take confidence in the fact that model has been properly implemented

  15. ECHR and national constitutional courts

    Directory of Open Access Journals (Sweden)

    Nastić Maja

    2015-01-01

    Full Text Available Comprising fundamental rights and freedoms and establishing the effective control system, the European Convention on Human Rights (ECHR encroaches upon the area that is traditional reserved for constitutional law. Although built on the doctrine reserved for international treaty law, the Convention goes beyond the traditional boundaries that exist between international and constitutional law. It has gradually infiltrated into the national legal systems. Constitutional courts have had the crucial role in this process. This paper will focus on the applicability of the ECHR in proceedings before national constitutional courts. Having in mind the jurisdiction of the national constitutional court, the ECHR may be applied in two ways: first, in the process of constitutional review by national constitutional courts and, second, in the process of deciding on constitutional complaints.

  16. VALUATION IN THE CONSTITUTIONAL ERA

    African Journals Online (AJOL)

    Brimer

    16 ..... stem from the pre-constitutional era, and the constitutional framework and its legitimate reform efforts. A decision on what is just ...... Carroll L Alice's Adventures in Wonderland (Digital Scanning Scituate MA. 2007). Dagan 1999 Va L Rev.

  17. The Na+/H+ exchanger NHE1, but not the Na+, HCO3- cotransporter NBCn1, regulates motility of MCF7 breast cancer cells expressing constitutively active ErbB2

    DEFF Research Database (Denmark)

    Lauritzen, Gitte; Stock, Christian-Martin; Lemaire, Justine

    2012-01-01

    We and others have shown central roles of the Na(+)/H(+) exchanger NHE1 in cell motility. The aim of this study was to determine the roles of NHE1 and of the Na(+), HCO(3)(-) cotransporter NBCn1 in motility of serum-starved MCF-7 breast cancer cells expressing constitutively active ErbB2 (¿NErbB2...

  18. Legal theology in imposed constitutionalism

    DEFF Research Database (Denmark)

    Abat Ninet, Antoni

    2018-01-01

    The focus of this paper is the question of legitimacy, and how can we consider legitimate an imposed constitution and the subsequent constitutional principles, practices and values that go hand-in-hand with the legal and political acculturation. Constitutional texts around the world are good...

  19. The diffusion of constitutional rights

    NARCIS (Netherlands)

    Goderis, B.V.G.; Versteeg, M.

    Constitutions are commonly regarded as uniquely national products, shaped by domestic ideals and politics. This paper develops and empirically investigates a novel hypothesis, which is that constitutions are also shaped by transnational influence, or “diffusion.” Constitutional rights can diffuse

  20. Ontoteleological Constitution of Entrepreneurship

    Directory of Open Access Journals (Sweden)

    Diego Luiz Teixeira Boava

    2017-06-01

    Full Text Available Entrepreneurship is a pluri-disciplinary phenomenon, object of research in several areas of knowledge. However, studies on this theme present approaches that start to consider entrepreneurship as a field of private knowledge in the phase of epistemological construction. In this context, the aim of this investigation is to contribute to the discussions on the theme, through studies on the ontoteleological constitution of entrepreneurship, in propaedeutic character, deflagrating new approaches. Thus, there is a presentation concerning the study of entrepreneurship, which may emphasize its ontical and ontological aspects. In addition, the reason why it is complex to define entrepreneurship is investigated. Subjects regarding the philosophy of entrepreneurship are introduced, seeking to present the bases for an ontoteleological approach to the phenomenon. Such an approach assumes that the finality of the entrepreneurial act relates to the main principles and transformations required into the organization. Finally, it is concluded that man is an entrepreneurial being, the meta-entrepreneur, and his entrepreneurial actions are not determined by external factors, but rather by the condition of his potentiality.

  1. Evolutionary history and functional divergence of the cytochrome P450 gene superfamily between Arabidopsis thaliana and Brassica species uncover effects of whole genome and tandem duplications.

    Science.gov (United States)

    Yu, Jingyin; Tehrim, Sadia; Wang, Linhai; Dossa, Komivi; Zhang, Xiurong; Ke, Tao; Liao, Boshou

    2017-09-18

    The cytochrome P450 monooxygenase (P450) superfamily is involved in the biosynthesis of various primary and secondary metabolites. However, little is known about the effects of whole genome duplication (WGD) and tandem duplication (TD) events on the evolutionary history and functional divergence of P450s in Brassica after splitting from a common ancestor with Arabidopsis thaliana. Using Hidden Markov Model search and manual curation, we detected that Brassica species have nearly 1.4-fold as many P450 members as A. thaliana. Most P450s in A. thaliana and Brassica species were located on pseudo-chromosomes. The inferred phylogeny indicated that all P450s were clustered into two different subgroups. Analysis of WGD event revealed that different P450 gene families had appeared after evolutionary events of species. For the TD event analyses, the P450s from TD events in Brassica species can be divided into ancient and recent parts. Our comparison of influence of WGD and TD events on the P450 gene superfamily between A. thaliana and Brassica species indicated that the family-specific evolution in the Brassica lineage can be attributed to both WGD and TD, whereas WGD was recognized as the major mechanism for the recent evolution of the P450 super gene family. Expression analysis of P450s from A. thaliana and Brassica species indicated that WGD-type P450s showed the same expression pattern but completely different expression with TD-type P450s across different tissues in Brassica species. Selection force analysis suggested that P450 orthologous gene pairs between A. thaliana and Brassica species underwent negative selection, but no significant differences were found between P450 orthologous gene pairs in A. thaliana-B. rapa and A. thaliana-B. oleracea lineages, as well as in different subgenomes in B. rapa or B. oleracea compared with A. thaliana. This study is the first to investigate the effects of WGD and TD on the evolutionary history and functional divergence of P450

  2. A class V chitinase from Arabidopsis thaliana: gene responses, enzymatic properties, and crystallographic analysis

    DEFF Research Database (Denmark)

    Ohnuma, Takayuki; Numata, Tomoyuki; Osawa, Takuo

    2011-01-01

    Expression of a class V chitinase gene (At4g19810, AtChiC) in Arabidopsis thaliana was examined by quantitative real-time PCR and by analyzing microarray data available at Genevestigator. The gene expression was induced by the plant stress-related hormones abscisic acid (ABA) and jasmonic acid (JA......, the amino acid residues responsible for substrate binding were found to be well conserved when compared with those of the class V chitinase from Nicotiana tabacum (NtChiV). All of the structural and functional properties of AtChiC are quite similar to those obtained for NtChiV, and seem to be common...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  4. Co-regulation of the atrial natriuretic factor and cardiac myosin light chain-2 genes during alpha-adrenergic stimulation of neonatal rat ventricular cells. Identification of cis sequences within an embryonic and a constitutive contractile protein gene which mediate inducible expression.

    Science.gov (United States)

    Knowlton, K U; Baracchini, E; Ross, R S; Harris, A N; Henderson, S A; Evans, S M; Glembotski, C C; Chien, K R

    1991-04-25

    To study the mechanisms which mediate the transcriptional activation of cardiac genes during alpha adrenergic stimulation, the present study examined the regulated expression of three cardiac genes, a ventricular embryonic gene (atrial natriuretic factor, ANF), a constitutively expressed contractile protein gene (cardiac MLC-2), and a cardiac sodium channel gene. alpha 1-Adrenergic stimulation activates the expression and release of ANF from neonatal ventricular cells. As assessed by RNase protection analyses, treatment with alpha-adrenergic agonists increases the steady-state levels of ANF mRNA by greater than 15-fold. However, a rat cardiac sodium channel gene mRNA is not induced, indicating that alpha-adrenergic stimulation does not lead to an increase in the expression of all cardiac genes. Studies employing a series of rat ANF luciferase and rat MLC-2 luciferase fusion genes identify 315- and 92-base pair cis regulatory sequences within an embryonic gene (ANF) and a constitutively expressed contractile protein gene (MLC-2), respectively, which mediate alpha-adrenergic-inducible gene expression. Transfection of various ANF luciferase reporters into neonatal rat ventricular cells demonstrated that upstream sequences which mediate tissue-specific expression (-3003 to -638) can be segregated from those responsible for inducibility. The lack of inducibility of a cardiac Na+ channel gene, and the segregation of ANF gene sequences which mediate cardiac specific from those which mediate inducible expression, provides further insight into the relationship between muscle-specific and inducible expression during cardiac myocyte hypertrophy. Based on these results, a testable model is proposed for the induction of embryonic cardiac genes and constitutively expressed contractile protein genes and the noninducibility of a subset of cardiac genes during alpha-adrenergic stimulation of neonatal rat ventricular cells.

  5. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    Directory of Open Access Journals (Sweden)

    Mari Narusaka

    Full Text Available Housaku Monogatari (HM is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods.

  6. Constitutively Elevated Salicylic Acid Levels Alter Photosynthesis and Oxidative State but Not Growth in Transgenic Populus[C][W

    Science.gov (United States)

    Xue, Liang-Jiao; Guo, Wenbing; Yuan, Yinan; Anino, Edward O.; Nyamdari, Batbayar; Wilson, Mark C.; Frost, Christopher J.; Chen, Han-Yi; Babst, Benjamin A.; Harding, Scott A.; Tsai, Chung-Jui

    2013-01-01

    Salicylic acid (SA) has long been implicated in plant responses to oxidative stress. SA overproduction in Arabidopsis thaliana leads to dwarfism, making in planta assessment of SA effects difficult in this model system. We report that transgenic Populus tremula × alba expressing a bacterial SA synthase hyperaccumulated SA and SA conjugates without negative growth consequences. In the absence of stress, endogenously elevated SA elicited widespread metabolic and transcriptional changes that resembled those of wild-type plants exposed to oxidative stress-promoting heat treatments. Potential signaling and oxidative stress markers azelaic and gluconic acids as well as antioxidant chlorogenic acids were strongly coregulated with SA, while soluble sugars and other phenylpropanoids were inversely correlated. Photosynthetic responses to heat were attenuated in SA-overproducing plants. Network analysis identified potential drivers of SA-mediated transcriptome rewiring, including receptor-like kinases and WRKY transcription factors. Orthologs of Arabidopsis SA signaling components NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 and thioredoxins were not represented. However, all members of the expanded Populus nucleoredoxin-1 family exhibited increased expression and increased network connectivity in SA-overproducing Populus, suggesting a previously undescribed role in SA-mediated redox regulation. The SA response in Populus involved a reprogramming of carbon uptake and partitioning during stress that is compatible with constitutive chemical defense and sustained growth, contrasting with the SA response in Arabidopsis, which is transient and compromises growth if sustained. PMID:23903318

  7. Multiple paths to similar germination behavior in Arabidopsis thaliana.

    Science.gov (United States)

    Burghardt, Liana T; Edwards, Brianne R; Donohue, Kathleen

    2016-02-01

    Germination timing influences plant fitness, and its sensitivity to temperature may cause it to change as climate shifts. These changes are likely to be complex because temperatures that occur during seed maturation and temperatures that occur post-dispersal interact to define germination timing. We used the model organism Arabidopsis thaliana to determine how flowering time (which defines seed-maturation temperature) and post-dispersal temperature influence germination and the expression of genetic variation for germination. Germination responses to temperature (germination envelopes) changed as seeds aged, or after-ripened, and these germination trajectories depended on seed-maturation temperature and genotype. Different combinations of genotype, seed-maturation temperature, and after-ripening produced similar germination envelopes. Likewise, different genotypes and seed-maturation temperatures combined to produce similar germination trajectories. Differences between genotypes were most likely to be observed at high and low germination temperatures. The germination behavior of some genotypes responds weakly to maternal temperature but others are highly plastic. We hypothesize that weak dormancy induction could synchronize germination of seeds dispersed at different times. By contrast, we hypothesize that strongly responsive genotypes may spread offspring germination over several possible germination windows. Considering germination responses to temperature is important for predicting phenology expression and evolution in future climates. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  8. Transcriptional responses of Arabidopsis thaliana plants to As (V stress

    Directory of Open Access Journals (Sweden)

    Yuan Joshua S

    2008-08-01

    Full Text Available Abstract Background Arsenic is toxic to plants and a common environmental pollutant. There is a strong chemical similarity between arsenate [As (V] and phosphate (Pi. Whole genome oligonucleotide microarrays were employed to investigate the transcriptional responses of Arabidopsis thaliana plants to As (V stress. Results Antioxidant-related genes (i.e. coding for superoxide dismutases and peroxidases play prominent roles in response to arsenate. The microarray experiment revealed induction of chloroplast Cu/Zn superoxide dismutase (SOD (at2g28190, Cu/Zn SOD (at1g08830, as well as an SOD copper chaperone (at1g12520. On the other hand, Fe SODs were strongly repressed in response to As (V stress. Non-parametric rank product statistics were used to detect differentially expressed genes. Arsenate stress resulted in the repression of numerous genes known to be induced by phosphate starvation. These observations were confirmed with qRT-PCR and SOD activity assays. Conclusion Microarray data suggest that As (V induces genes involved in response to oxidative stress and represses transcription of genes induced by phosphate starvation. This study implicates As (V as a phosphate mimic in the cell by repressing genes normally induced when available phosphate is scarce. Most importantly, these data reveal that arsenate stress affects the expression of several genes with little or unknown biological functions, thereby providing new putative gene targets for future research.

  9. Constitution, 1989. [Selected provisions].

    Science.gov (United States)

    1989-01-01

    Chapter XII of the Hungarian Constitution, 1989, details the Fundamental Rights and Duties of Citizens. Everyone lawfully within the territory of Hungary has the right to liberty of movement and the freedom to choose his or her residence, except when restricted by law, including the right to leave his or her residence or county. The Republic of Hungary grants asylum to foreign citizens who were persecuted for racial, religious ethnic, linguistic, or political reasons. Men and women shall equally enjoy all civil, political, economic, social and political rights. Mothers are entitled to special care and protection before and after childbirth; women and juveniles are protected at work by special regulations. Every child has the right to special care an assistance from his or her family, the State, and society, for appropriate physical, spiritual, and moral development. Parents shall decide the kind of education their children receive. Hungary grants equal rights to all person within its territories, without regard to race, color, sex, language, religion, political, or other opinion, national, and social origin, property, birth and other status. Prejudicial discrimination shall be severely punished. Everyone has the right to work, to the free choice of employment and profession and to equal pay for equal work. Citizens have the right to social security, including social services necessary in old age, sickness, disability, widowhood, orphanhood an unemployment through no fault of their own. Hungary guarantees the right to culture for its citizens and realized this right by free and compulsory elementary education, by secondary and higher education which is accessible to all on the basis of capacity, and by the financial support of those receiving an education.

  10. Constitutive equations for Zr1Nb. II

    International Nuclear Information System (INIS)

    Novak, J.

    1986-01-01

    Based on existing knowledge and constitutive equations for non-irradiated material, constitutive equations were written for Zr1Nb irradiated at 573 K at deformation in the direction of forming. Constitutive equations express the following material characteristics: dependence of shear strength on fast neutron fluence, superposition of deformation hardening and subsequent radiation hardening, the effect of stress on deformation rate, and for fluences above ca. 10 24 n.m -2 (E>1 MeV) the course of the deformation curve for various fluence levels. The values apply for temperatures and rates of deformation which are characteristic of transient processes during changes in the power output of fuel elements of pressurized water reactors. (J.B.)

  11. Constitutional judges (guarantee of the Constitution and responsibility

    Directory of Open Access Journals (Sweden)

    Francisco Javier Ansuátegui Roig

    2012-06-01

    Full Text Available My aim in this paper is to propose a reflection on the position and the importance that the constitutional judge has in the legal systems of contemporary constitutionalism. The figure of the judge responsible of protecting the Constitution is a key institution, without which we cannot understand the laws of constitutional democracies, their current lines of development, and the guarantee of rights and freedoms that constitute the normative core of these systems. Moreover, the reflection on the exercise of the powers of the judge, its scope and its justification is an important part of contemporary legal discussion, still relevant, albeit not exclusively - in the field of legal philosophy. The object of attention of my reflection is the judge who has the power of judicial review, in a scheme of defense of the Constitution, regardless the specific ways of this defense.

  12. Human intrinsic factor expressed in the plant Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Fedosov, Sergey N; Laursen, Niels B; Nexø, Ebba

    2003-01-01

    Intrinsic factor (IF) is the gastric protein that promotes the intestinal uptake of vitamin B12. Gastric IF from animal sources is used in diagnostic tests and in vitamin pills. However, administration of animal IF to humans becomes disadvantageous because of possible pathogenic transmission...

  13. Allyl Isothiocyanate Inhibits Actin-Dependent Intracellular Transport in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Bjørnar Sporsheim

    2015-12-01

    Full Text Available Volatile allyl isothiocyanate (AITC derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In this study, we present evidence of an AITC-induced inhibition of actin-dependent intracellular transport in A. thaliana. A transgenic line of A. thaliana expressing yellow fluorescent protein (YFP-tagged actin filaments was used to show attenuation of actin filament movement by AITC. This appeared gradually in a time- and dose-dependent manner and resulted in actin filaments appearing close to static. Further, we employed four transgenic lines with YFP-fusion proteins labeling the Golgi apparatus, endoplasmic reticulum (ER, vacuoles and peroxisomes to demonstrate an AITC-induced inhibition of actin-dependent intracellular transport of or, in these structures, consistent with the decline in actin filament movement. Furthermore, the morphologies of actin filaments, ER and vacuoles appeared aberrant following AITC-exposure. However, AITC-treated seedlings of all transgenic lines tested displayed morphologies and intracellular movements similar to that of the corresponding untreated and control-treated plants, following overnight incubation in an AITC-absent environment, indicating that AITC-induced decline in actin-related movements is a reversible process. These findings provide novel insights into the cellular events in plant cells following exposure to AITC, which may further expose clues to the physiological significance of the glucosinolate-myrosinase system.

  14. Long noncoding RNAs responsive to Fusarium oxysporum infection in Arabidopsis thaliana.

    Science.gov (United States)

    Zhu, Qian-Hao; Stephen, Stuart; Taylor, Jennifer; Helliwell, Chris A; Wang, Ming-Bo

    2014-01-01

    Short noncoding RNAs have been demonstrated to play important roles in regulation of gene expression and stress responses, but the repertoire and functions of long noncoding RNAs (lncRNAs) remain largely unexplored, particularly in plants. To explore the role of lncRNAs in disease resistance, we used a strand-specific RNA-sequencing approach to identify lncRNAs responsive to Fusarium oxysporum infection in Arabidopsis thaliana. Antisense transcription was found in c. 20% of the annotated A. thaliana genes. Several noncoding natural antisense transcripts responsive to F. oxysporum infection were found in genes implicated in disease defense. While the majority of the novel transcriptionally active regions (TARs) were adjacent to annotated genes and could be an extension of the annotated transcripts, 159 novel intergenic TARs, including 20 F. oxysporum-responsive lncTARs, were identified. Ten F. oxysporum-induced lncTARs were functionally characterized using T-DNA insertion or RNA-interference knockdown lines, and five were demonstrated to be related to disease development. Promoter analysis suggests that some of the F. oxysporum-induced lncTARs are direct targets of transcription factor(s) responsive to pathogen attack. Our results demonstrated that strand-specific RNA sequencing is a powerful tool for uncovering hidden levels of transcriptome and that IncRNAs are important components of the antifungal networks in A. thaliana. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  15. Essential Medicines in National Constitutions

    Science.gov (United States)

    Toebes, Brigit; Hogerzeil, Hans

    2016-01-01

    Abstract A constitutional guarantee of access to essential medicines has been identified as an important indicator of government commitment to the progressive realization of the right to the highest attainable standard of health. The objective of this study was to evaluate provisions on access to essential medicines in national constitutions, to identify comprehensive examples of constitutional text on medicines that can be used as a model for other countries, and to evaluate the evolution of constitutional medicines-related rights since 2008. Relevant articles were selected from an inventory of constitutional texts from WHO member states. References to states’ legal obligations under international human rights law were evaluated. Twenty-two constitutions worldwide now oblige governments to protect and/or to fulfill accessibility of, availability of, and/or quality of medicines. Since 2008, state responsibilities to fulfill access to essential medicines have expanded in five constitutions, been maintained in four constitutions, and have regressed in one constitution. Government commitments to essential medicines are an important foundation of health system equity and are included increasingly in state constitutions. PMID:27781006

  16. Identification of Polyadenylation Sites within Arabidopsis Thaliana

    KAUST Repository

    Kalkatawi, Manal

    2011-09-01

    Machine Learning (ML) is a field of artificial intelligence focused on the design and implementation of algorithms that enable creation of models for clustering, classification, prediction, ranking and similar inference tasks based on information contained in data. Many ML algorithms have been successfully utilized in a variety of applications. The problem addressed in this thesis is from the field of bioinformatics and deals with the recognition of polyadenylation (poly(A)) sites in the genomic sequence of the plant Arabidopsis thaliana. During the RNA processing, a tail consisting of a number of consecutive adenine (A) nucleotides is added to the terminal nucleotide of the 3’- untranslated region (3’UTR) of the primary RNA. The process in which these A nucleotides are added is called polyadenylation. The location in the genomic DNA sequence that corresponds to the start of terminal A nucleotides (i.e. to the end of 3’UTR) is known as a poly(A) site. Recognition of the poly(A) sites in DNA sequence is important for better gene annotation and understanding of gene regulation. In this study, we built an artificial neural network (ANN) for the recognition of poly(A) sites in the Arabidopsis thaliana genome. Our study demonstrates that this model achieves improved accuracy compared to the existing predictive models for this purpose. The key factor contributing to the enhanced predictive performance of our ANN model is a distinguishing set of features used in creation of the model. These features include a number of physico-chemical characteristics of relevance, such as dinucleotide thermodynamic characteristics, electron-ion interaction potential, etc., but also many of the statistical properties of the DNA sequences from the region surrounding poly(A) site, such as nucleotide and polynucleotide properties, common motifs, etc. Our ANN model was compared in performance with several other ML models, as well as with the PAC tool that is specifically developed for

  17. Dissecting a hidden gene duplication: the Arabidopsis thaliana SEC10 locus.

    Directory of Open Access Journals (Sweden)

    Nemanja Vukašinović

    Full Text Available Repetitive sequences present a challenge for genome sequence assembly, and highly similar segmental duplications may disappear from assembled genome sequences. Having found a surprising lack of observable phenotypic deviations and non-Mendelian segregation in Arabidopsis thaliana mutants in SEC10, a gene encoding a core subunit of the exocyst tethering complex, we examined whether this could be explained by a hidden gene duplication. Re-sequencing and manual assembly of the Arabidopsis thaliana SEC10 (At5g12370 locus revealed that this locus, comprising a single gene in the reference genome assembly, indeed contains two paralogous genes in tandem, SEC10a and SEC10b, and that a sequence segment of 7 kb in length is missing from the reference genome sequence. Differences between the two paralogs are concentrated in non-coding regions, while the predicted protein sequences exhibit 99% identity, differing only by substitution of five amino acid residues and an indel of four residues. Both SEC10 genes are expressed, although varying transcript levels suggest differential regulation. Homozygous T-DNA insertion mutants in either paralog exhibit a wild-type phenotype, consistent with proposed extensive functional redundancy of the two genes. By these observations we demonstrate that recently duplicated genes may remain hidden even in well-characterized genomes, such as that of A. thaliana. Moreover, we show that the use of the existing A. thaliana reference genome sequence as a guide for sequence assembly of new Arabidopsis accessions or related species has at least in some cases led to error propagation.

  18. Constitutional aneuploidy and cancer predisposition.

    Science.gov (United States)

    Ganmore, Ithamar; Smooha, Gil; Izraeli, Shai

    2009-04-15

    Constitutional aneuploidies are rare syndromes associated with multiple developmental abnormalities and the alterations in the risk for specific cancers. Acquired somatic chromosomal aneuploidies are the most common genetic aberrations in sporadic cancers. Thus studies of these rare constitutional aneuploidy syndromes are important not only for patient counseling and clinical management, but also for deciphering the mechanisms by which chromosomal aneuploidy affect cancer initiation and progression. Here we review the major constitutional aneuploidy syndromes and suggest some general mechanisms for the associated cancer predisposition.

  19. Economic Reforms and Constitutional Transition

    OpenAIRE

    Jeffrey D. Sachs; Wing Thye Woo; Xiaokai Yang

    2000-01-01

    This paper investigates the relationship between economic reforms and constitutional transition, which has been neglected by many transition economists. It is argued that assessment of reform performance might be very misleading if it is not recognized that economic reforms are just a small part of large scale of constitutional transition. Rivalry and competition between states and between political forces within each country are the driving forces for constitutional transition. We use Russia...

  20. ECHR and national constitutional courts

    OpenAIRE

    Nastić, Maja

    2015-01-01

    Comprising fundamental rights and freedoms and establishing the effective control system, the European Convention on Human Rights (ECHR) encroaches upon the area that is traditional reserved for constitutional law. Although built on the doctrine reserved for international treaty law, the Convention goes beyond the traditional boundaries that exist between international and constitutional law. It has gradually infiltrated into the national legal systems. Constitutional courts have had the cruc...

  1. Constitutional Issues--Watergate and the Constitution. Teaching with Documents.

    Science.gov (United States)

    National Archives and Records Administration, Washington, DC.

    When U.S. President Richard Nixon resigned in 1974 in the wake of the Watergate scandal, it was only the second time that impeachment of a president had been considered. Although the U.S. Constitution has provisions for a person removed from office to be indicted, there are no guidelines in the Constitution about a President who has resigned. The…

  2. the meaning of the provision of the 1996 constitution | Venter ...

    African Journals Online (AJOL)

    The introduction of this notion in South African law and its meaning in general is ... be it of a private or public law nature, can escape the test of constitutionality. ... to international authorities and definitions of these concepts are developed. ... The Constitutional Court has determined that, although no express provision to this ...

  3. National constitutional courts in the European Constitutional Democracy

    DEFF Research Database (Denmark)

    Komárek, Jan

    2014-01-01

    This article critically assesses the transformation of national constitutional courts’ place in the law and politics of the EU and its member states. This process eliminates the difference between constitutional and ordinary national courts, which is crucial for the institutional implementation...... of the discourse theory of law and democracy. It also disrupts the symbiotic relationship between national constitutional democracies established after World War II and European integration. The article argues that maintaining the special place of national constitutional courts is in the vital interest of both...... the EU and its member states, understood together as the European Constitutional Democracy—the central notion developed in this article in order to support an argument that should speak to both EU lawyers and national constitutionalists....

  4. Effects of tung oilseed FAD2 and DGAT2 genes on unsaturated fatty acid accumulation in Rhodotorula glutinis and Arabidopsis thaliana.

    Science.gov (United States)

    Chen, Yicun; Cui, Qinqin; Xu, Yongjie; Yang, Susu; Gao, Ming; Wang, Yangdong

    2015-08-01

    Genetic engineering to produce valuable lipids containing unsaturated fatty acids (UFAs) holds great promise for food and industrial applications. Efforts to genetically modify plants to produce desirable UFAs with single enzymes, however, have had modest success. The key enzymes fatty acid desaturase (FAD) and diacylglycerol acyltransferase (DGAT) are responsible for UFA biosynthesis (a push process) and assembling fatty acids into lipids (a pull process) in plants, respectively. To examine their roles in UFA accumulation, VfFAD2 and VfDGAT2 genes cloned from Vernicia fordii (tung tree) oilseeds were conjugated and transformed into Rhodotorula glutinis and Arabidopsis thaliana via Agrobacterium tumefaciens. Real-time quantitative PCR revealed variable gene expression levels in the transformants, with a much higher level of VfDGAT2 than VfFAD2. The relationship between VfFAD2 expression and linoleic acid (C18:2) increases in R. glutinis (R (2) = 0.98) and A. thaliana (R (2) = 0.857) transformants was statistically linear. The VfDGAT2 expression level was statistically correlated with increased total fatty acid content in R. glutinis (R (2) = 0.962) and A. thaliana (R (2) = 0.8157) transformants. With a similar expression level between single- and two-gene transformants, VfFAD2-VfDGAT2 co-transformants showed a higher linolenic acid (C18:3) yield in R. glutinis (174.36 % increase) and A. thaliana (14.61 % increase), and eicosatrienoic acid (C20:3) was enriched (17.10 % increase) in A. thaliana. Our data suggest that VfFAD2-VfDGAT2 had a synergistic effect on UFA metabolism in R. glutinis, and to a lesser extent, A. thaliana. These results show promise for further genetic engineering of plant lipids to produce desirable UFAs.

  5. Characterization of the Arabidopsis thaliana 2-Cys peroxiredoxin interactome.

    Science.gov (United States)

    Cerveau, Delphine; Kraut, Alexandra; Stotz, Henrik U; Mueller, Martin J; Couté, Yohann; Rey, Pascal

    2016-11-01

    Peroxiredoxins are ubiquitous thiol-dependent peroxidases for which chaperone and signaling roles have been reported in various types of organisms in recent years. In plants, the peroxidase function of the two typical plastidial 2-Cys peroxiredoxins (2-Cys PRX A and B) has been highlighted while the other functions, particularly in ROS-dependent signaling pathways, are still elusive notably due to the lack of knowledge of interacting partners. Using an ex vivo approach based on co-immunoprecipitation of leaf extracts from Arabidopsis thaliana wild-type and mutant plants lacking 2-Cys PRX expression followed by mass spectrometry-based proteomics, 158 proteins were found associated with 2-Cys PRXs. Already known partners like thioredoxin-related electron donors (Chloroplastic Drought-induced Stress Protein of 32kDa, Atypical Cysteine Histidine-rich Thioredoxin 2) and enzymes involved in chlorophyll synthesis (Protochlorophyllide OxidoReductase B) or carbon metabolism (Fructose-1,6-BisPhosphatase) were identified, validating the relevance of the approach. Bioinformatic and bibliographic analyses allowed the functional classification of the identified proteins and revealed that more than 40% are localized in plastids. The possible roles of plant 2-Cys PRXs in redox signaling pathways are discussed in relation with the functions of the potential partners notably those involved in redox homeostasis, carbon and amino acid metabolisms as well as chlorophyll biosynthesis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. The Hidden Geometries of the Arabidopsis thaliana Epidermis

    KAUST Repository

    Staff, Lee; Hurd, Patricia; Reale, Lara; Seoighe, Cathal; Rockwood, Alyn; Gehring, Christoph A

    2012-01-01

    The quest for the discovery of mathematical principles that underlie biological phenomena is ancient and ongoing. We present a geometric analysis of the complex interdigitated pavement cells in the Arabidopsis thaliana (Col.) adaxial epidermis

  7. Expression

    Directory of Open Access Journals (Sweden)

    Wang-Xia Wang

    2014-02-01

    Full Text Available The miR-15/107 family comprises a group of 10 paralogous microRNAs (miRNAs, sharing a 5′ AGCAGC sequence. These miRNAs have overlapping targets. In order to characterize the expression of miR-15/107 family miRNAs, we employed customized TaqMan Low-Density micro-fluid PCR-array to investigate the expression of miR-15/107 family members, and other selected miRNAs, in 11 human tissues obtained at autopsy including the cerebral cortex, frontal cortex, primary visual cortex, thalamus, heart, lung, liver, kidney, spleen, stomach and skeletal muscle. miR-103, miR-195 and miR-497 were expressed at similar levels across various tissues, whereas miR-107 is enriched in brain samples. We also examined the expression patterns of evolutionarily conserved miR-15/107 miRNAs in three distinct primary rat brain cell preparations (enriched for cortical neurons, astrocytes and microglia, respectively. In primary cultures of rat brain cells, several members of the miR-15/107 family are enriched in neurons compared to other cell types in the central nervous system (CNS. In addition to mature miRNAs, we also examined the expression of precursors (pri-miRNAs. Our data suggested a generally poor correlation between the expression of mature miRNAs and their precursors. In summary, we provide a detailed study of the tissue and cell type-specific expression profile of this highly expressed and phylogenetically conserved family of miRNA genes.

  8. Combined Metabonomic and Quantitative RT-PCR Analyses Revealed Metabolic Reprogramming Associated with Fusarium graminearum Resistance in Transgenic Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Fangfang Chen

    2018-01-01

    Full Text Available Fusarium head blight disease resulting from Fusarium graminearum (FG infection causes huge losses in global production of cereals and development of FG-resistant plants is urgently needed. To understand biochemistry mechanisms for FG resistance, here, we have systematically investigated the plant metabolomic phenotypes associated with FG resistance for transgenic Arabidopsis thaliana expressing a class-I chitinase (Chi, a Fusarium-specific recombinant antibody gene (CWP2 and fused Chi-CWP2. Plant disease indices, mycotoxin levels, metabonomic characteristics, and expression levels of several key genes were measured together with their correlations. We found that A. thaliana expressing Chi-CWP2 showed higher FG resistance with much lower disease indices and mycotoxin levels than the wild-type and the plants expressing Chi or CWP2 alone. The combined metabonomic and quantitative RT-PCR analyses revealed that such FG-resistance was closely associated with the promoted biosynthesis of secondary metabolites (phenylpropanoids, alkanoids and organic osmolytes (proline, betaine, glucose, myo-inositol together with enhanced TCA cycle and GABA shunt. These suggest that the concurrently enhanced biosyntheses of the shikimate-mediated secondary metabolites and organic osmolytes be an important strategy for A. thaliana to develop and improve FG resistance. These findings provide essential biochemical information related to FG resistance which is important for developing FG-resistant cereals.

  9. Constitutive Effects of Performance Indicators

    DEFF Research Database (Denmark)

    Dahler-Larsen, Peter

    2014-01-01

    that are demonstrably problematic. Based on a distinction between trivial and advanced measure fixation, an argument is made for constitutive effects that are based on less problematic assumptions. Through this conceptual move, the political dimension of performance indicators is appreciated. The conceptual dimensions...... of constitutive effects are carved out, empirical illustrations of their applicability are offered and implications discussed....

  10. Molecular signatures in Arabidopsis thaliana in response to insect attack and bacterial infection.

    Science.gov (United States)

    Barah, Pankaj; Winge, Per; Kusnierczyk, Anna; Tran, Diem Hong; Bones, Atle M

    2013-01-01

    Under the threat of global climatic change and food shortages, it is essential to take the initiative to obtain a comprehensive understanding of common and specific defence mechanisms existing in plant systems for protection against different types of biotic invaders. We have implemented an integrated approach to analyse the overall transcriptomic reprogramming and systems-level defence responses in the model plant species Arabidopsis thaliana (A. thaliana henceforth) during insect Brevicoryne brassicae (B. brassicae henceforth) and bacterial Pseudomonas syringae pv. tomato strain DC3000 (P. syringae henceforth) attacks. The main aim of this study was to identify the attacker-specific and general defence response signatures in A. thaliana when attacked by phloem-feeding aphids or pathogenic bacteria. The obtained annotated networks of differentially expressed transcripts indicated that members of transcription factor families, such as WRKY, MYB, ERF, BHLH and bZIP, could be crucial for stress-specific defence regulation in Arabidopsis during aphid and P. syringae attack. The defence response pathways, signalling pathways and metabolic processes associated with aphid attack and P. syringae infection partially overlapped. Components of several important biosynthesis and signalling pathways, such as salicylic acid (SA), jasmonic acid (JA), ethylene (ET) and glucosinolates, were differentially affected during the two the treatments. Several stress-regulated transcription factors were known to be associated with stress-inducible microRNAs. The differentially regulated gene sets included many signature transcription factors, and our co-expression analysis showed that they were also strongly co-expressed during 69 other biotic stress experiments. Defence responses and functional networks that were unique and specific to aphid or P. syringae stresses were identified. Furthermore, our analysis revealed a probable link between biotic stress and microRNAs in Arabidopsis and

  11. Political dimension of European constitutionalism

    Directory of Open Access Journals (Sweden)

    Kaplánová Patricia

    2015-04-01

    Full Text Available Author in the article tries to analyse different elements of document called European Constitution. Analysis is supported with theoretical framework of federalism, presented by Brezovšek. Authors is playing with idea of (confederal and international organization elements of European Constitution and their mix. They are also trying to set some connections between so called common European identity as necessary condition to give legitimacy to the European Constitution. This became important question after „votes of non-confidence“ to the European Constitution in France, despite it should be addressed already before. However, European Constitution is important document on the path of European integration and lack of support to it will slow down this process of widening and deepening European ties.

  12. Biochemical and genetic characterization of three molybdenum cofactor hydroxylases in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Hoff, Tine; Frandsen, Gitte Inselmann; Rocher, Anne

    1998-01-01

    Aldehyde oxidases and xanthine dehydrogenases/oxidases belong to the molybdenum cofactor dependent hydroxylase class of enzymes. Zymograms show that Arabidopsis thaliana has at least three different aldehyde oxidases and one xanthine oxidase. Three different cDNA clones encoding putative aldehyde...... oxidases (AtAO1, 2, 3) were isolated. An aldehyde oxidase is the last step in abscisic acid (ABA) biosynthesis. AtAO1 is mainly expressed in seeds and roots which might reflect that it is involved in ABA biosynthesis....

  13. Constitutive equations for two-phase flows

    International Nuclear Information System (INIS)

    Boure, J.A.

    1974-12-01

    The mathematical model of a system of fluids consists of several kinds of equations complemented by boundary and initial conditions. The first kind equations result from the application to the system, of the fundamental conservation laws (mass, momentum, energy). The second kind equations characterize the fluid itself, i.e. its intrinsic properties and in particular its mechanical and thermodynamical behavior. They are the mathematical model of the particular fluid under consideration, the laws they expressed are so called the constitutive equations of the fluid. In practice the constitutive equations cannot be fully stated without reference to the conservation laws. Two classes of model have been distinguished: mixture model and two-fluid models. In mixture models, the mixture is considered as a single fluid. Besides the usual friction factor and heat transfer correlations, a single constitutive law is necessary. In diffusion models, the mixture equation of state is replaced by the phasic equations of state and by three consitutive laws, for phase change mass transfer, drift velocity and thermal non-equilibrium respectively. In the two-fluid models, the two phases are considered separately; two phasic equations of state, two friction factor correlations, two heat transfer correlations and four constitutive laws are included [fr

  14. A Mathematical Approach to Establishing Constitutive Models for Geomaterials

    Directory of Open Access Journals (Sweden)

    Guang-hua Yang

    2013-01-01

    Full Text Available The mathematical foundation of the traditional elastoplastic constitutive theory for geomaterials is presented from the mathematical point of view, that is, the expression of stress-strain relationship in principal stress/strain space being transformed to the expression in six-dimensional space. A new framework is then established according to the mathematical theory of vectors and tensors, which is applicable to establishing elastoplastic models both in strain space and in stress space. Traditional constitutive theories can be considered as its special cases. The framework also enables modification of traditional constitutive models.

  15. Capsella rubella TGA4, a bZIP transcription factor, causes delayed flowering in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Li Maofu

    2016-01-01

    Full Text Available Flowering time is usually regulated by many environmental factors and endogenous signals. TGA family members are bZIP transcription factors that bind to the octopine synthase element, which has been closely linked to defense/stress responses. Most TGA factors interact with non-expressor of PR1 (NPR1 and plant defense responses are strengthened by this interaction. TGA1and TGA4factors bind to NPR1 only in salicylic acid (SA-induced leaves, suggesting that TGA4 has another function during plant development. Here, we isolated a bZIP transcription factor gene, TGA4, from Capsella rubella. TGA4transcripts were detected in most tissues, with high expression in leaves, low expression in stems and flowering buds, and undetectable in siliques. CruTGA4was over expressed in Arabidopsis thaliana wild typeCol-0 plants. Flowering time and total leaf number in the transgenic plants showed that overexpression of CruTGA4could delay flowering in A. thaliana. Our findings suggest that TGA4 may act as flowering regulator that controls plant flowering.

  16. The FANTASTIC FOUR proteins influence shoot meristem size in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Brand Luise H

    2010-12-01

    Full Text Available Abstract Background Throughout their lives plants produce new organs from groups of pluripotent cells called meristems, located at the tips of the shoot and the root. The size of the shoot meristem is tightly controlled by a feedback loop, which involves the homeodomain transcription factor WUSCHEL (WUS and the CLAVATA (CLV proteins. This regulatory circuit is further fine-tuned by morphogenic signals such as hormones and sugars. Results Here we show that a family of four plant-specific proteins, encoded by the FANTASTIC FOUR (FAF genes, has the potential to regulate shoot meristem size in Arabidopsis thaliana. FAF2 and FAF4 are expressed in the centre of the shoot meristem, overlapping with the site of WUS expression. Consistent with a regulatory interaction between the FAF gene family and WUS, our experiments indicate that the FAFs can repress WUS, which ultimately leads to an arrest of meristem activity in FAF overexpressing lines. The finding that meristematic expression of FAF2 and FAF4 is under negative control by CLV3 further supports the hypothesis that the FAFs are modulators of the genetic circuit that regulates the meristem. Conclusion This study reports the initial characterization of the Arabidopsis thaliana FAF gene family. Our data indicate that the FAF genes form a plant specific gene family, the members of which have the potential to regulate the size of the shoot meristem by modulating the CLV3-WUS feedback loop.

  17. The FANTASTIC FOUR proteins influence shoot meristem size in Arabidopsis thaliana.

    Science.gov (United States)

    Wahl, Vanessa; Brand, Luise H; Guo, Ya-Long; Schmid, Markus

    2010-12-22

    Throughout their lives plants produce new organs from groups of pluripotent cells called meristems, located at the tips of the shoot and the root. The size of the shoot meristem is tightly controlled by a feedback loop, which involves the homeodomain transcription factor WUSCHEL (WUS) and the CLAVATA (CLV) proteins. This regulatory circuit is further fine-tuned by morphogenic signals such as hormones and sugars. Here we show that a family of four plant-specific proteins, encoded by the FANTASTIC FOUR (FAF) genes, has the potential to regulate shoot meristem size in Arabidopsis thaliana. FAF2 and FAF4 are expressed in the centre of the shoot meristem, overlapping with the site of WUS expression. Consistent with a regulatory interaction between the FAF gene family and WUS, our experiments indicate that the FAFs can repress WUS, which ultimately leads to an arrest of meristem activity in FAF overexpressing lines. The finding that meristematic expression of FAF2 and FAF4 is under negative control by CLV3 further supports the hypothesis that the FAFs are modulators of the genetic circuit that regulates the meristem. This study reports the initial characterization of the Arabidopsis thaliana FAF gene family. Our data indicate that the FAF genes form a plant specific gene family, the members of which have the potential to regulate the size of the shoot meristem by modulating the CLV3-WUS feedback loop.

  18. THE CONSTITUTIONAL PRINCIPLE OF EQUALITY - LEGAL SIGNIFICANCE AND SOCIAL IMPLICATIONS -

    Directory of Open Access Journals (Sweden)

    Marius ANDREESCU

    2017-12-01

    Full Text Available The equality in human rights and obligations, the equality of citizens before the law are fundamental categories of the theories on social democracy but also conditions of the lawful state, without which constitutional democracy cannot be conceived. In Romanian Constitution, this principle is consecrated in the form of equality of the citizens before the law and public authorities. There are also particular aspects of this principle consecrated in the Constitution. The constitutional principle of equality requires that equal treatment be applied to equal situations. This social and legal reality implies numerous interferences between the principle of equality and other constitutional principles. In this study, by using theoretical and jurisprudential arguments, we intend to demonstrate that, in relation to contemporary social reality, equality, as a constitutional principle, is a particular aspect of the principle of proportionality. The latter one expresses in essence the ideas of: fairness, justice, reasonableness and fair appropriateness of state decisions to the facts and legitimate aims proposed.

  19. Radioactive waste disposal and constitution

    International Nuclear Information System (INIS)

    Stober, R.

    1983-01-01

    The radioactive waste disposal has many dimensions with regard to the constitutional law. The central problem is the corret delimitation between adequate governmental precautions against risks and or the permitted risk which the state can impose on the citizen, and the illegal danger which nobody has to accept. The solution requires to consider all aspects which are relevant to the constitutional law. Therefore, the following analysis deals not only with the constitutional risks and the risks of the nuclear energy, but also with the liberal, overall-economic, social, legal, and democratic aspects of radioactive waste disposal. (HSCH) [de

  20. Constitutional aneuploidy and cancer predisposition†

    Science.gov (United States)

    Ganmore, Ithamar; Smooha, Gil; Izraeli, Shai

    2009-01-01

    Constitutional aneuploidies are rare syndromes associated with multiple developmental abnormalities and the alterations in the risk for specific cancers. Acquired somatic chromosomal aneuploidies are the most common genetic aberrations in sporadic cancers. Thus studies of these rare constitutional aneuploidy syndromes are important not only for patient counseling and clinical management, but also for deciphering the mechanisms by which chromosomal aneuploidy affect cancer initiation and progression. Here we review the major constitutional aneuploidy syndromes and suggest some general mechanisms for the associated cancer predisposition. PMID:19297405

  1. Multiwall carbon nanotubes modulate paraquat toxicity in Arabidopsis thaliana.

    Science.gov (United States)

    Fan, Xiaoji; Xu, Jiahui; Lavoie, Michel; Peijnenburg, W J G M; Zhu, Youchao; Lu, Tao; Fu, Zhengwei; Zhu, Tingheng; Qian, Haifeng

    2018-02-01

    Carbon nanotubes can be either toxic or beneficial to plant growth and can also modulate toxicity of organic contaminants through surface sorption. The complex interacting toxic effects of carbon nanotubes and organic contaminants in plants have received little attention in the literature to date. In this study, the toxicity of multiwall carbon nanotubes (MWCNT, 50 mg/L) and paraquat (MV, 0.82 mg/L), separately or in combination, were evaluated at the physiological and the proteomic level in Arabidopsis thaliana for 7-14 days. The results revealed that the exposure to MWCNT had no inhibitory effect on the growth of shoots and leaves. Rather, MWCNT stimulated the relative electron transport rate and the effective photochemical quantum yield of PSII value as compared to the control by around 12% and lateral root production up to nearly 4-fold as compared to the control. The protective effect of MWCNT on MV toxicity on the root surface area could be quantitatively explained by the extent of MV adsorption on MWCNT and was related to stimulation of photosynthesis, antioxidant protection and number and area of lateral roots which in turn helped nutrient assimilation. The influence of MWCNT and MV on photosynthesis and oxidative stress at the physiological level was consistent with the proteomics analysis, with various over-expressed photosynthesis-related proteins (by more than 2 folds) and various under-expressed oxidative stress related proteins (by about 2-3 folds). This study brings new insights into the interactive effects of two xenobiotics (MWCNT and MV) on the physiology of a model plant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Functional genetics of intraspecific ecological interactions in Arabidopsis thaliana.

    Science.gov (United States)

    Wolf, Jason B; Mutic, Joshua J; Kover, Paula X

    2011-05-12

    Studying the genetic basis of traits involved in ecological interactions is a fundamental part of elucidating the connections between evolutionary and ecological processes. Such knowledge allows one to link genetic models of trait evolution with ecological models describing interactions within and between species. Previous work has shown that connections between genetic and ecological processes in Arabidopsis thaliana may be mediated by the fact that quantitative trait loci (QTL) with 'direct' effects on traits of individuals also have pleiotropic 'indirect' effects on traits expressed in neighbouring plants. Here, we further explore these connections by examining functional relationships between traits affected directly and indirectly by the same QTL. We develop a novel approach using structural equation models (SEMs) to determine whether observed pleiotropic effects result from traits directly affected by the QTL in focal individuals causing the changes in the neighbours' phenotypes. This hypothesis was assessed using SEMs to test whether focal plant phenotypes appear to mediate the connection between the focal plants' genotypes and the phenotypes of their neighbours, or alternatively, whether the connection between the focal plants' genotypes and the neighbours' phenotypes is mediated by unmeasured traits. We implement this analysis using a QTL of major effect that maps to the well-characterized flowering locus, FRIGIDA. The SEMs support the hypothesis that the pleiotropic indirect effects of this locus arise from size and developmental timing-related traits in focal plants affecting the expression of developmental traits in their neighbours. Our findings provide empirical insights into the genetics and nature of intraspecific ecological interactions. Our technique holds promise in directing future work into the genetic basis and functional relationship of traits mediating and responding to ecological interactions.

  3. Burkholderia phytofirmans PsJN reduces damages to freezing temperature in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Fan eSU

    2015-10-01

    Full Text Available Several plant growth-promoting rhizobacteria (PGPR are known to improve plant tolerance to multiple stresses, including low temperatures. However, mechanisms underlying this protection are still poorly understood. The aim of this study was to evaluate the role of the endophytic PGPR, Burkholderia phytofirmans strain PsJN (Bp PsJN, on Arabidopsis thaliana cold tolerance using photosynthesis parameters as physiological markers.Under standard conditions, our results indicated that Bp PsJN inoculation led to growth promotion of Arabidopsis plants without significant modification on photosynthesis parameters and chloroplast organization. However, bacterial colonization induced a cell wall strengthening in the mesophyllImpact of inoculation modes (either on seeds or by soil irrigation and their effects overnight at 0, -1 or -3°C, were investigated by following photosystem II (PSII activity and gas exchanges. Following low temperatures stress, a decrease of photosynthesis parameters was observed. In addition, during three consecutive nights or days at -1°C, PSII activity was monitored. Pigment contents, RuBisCO protein abundance, expression of several genes including RbcS, RbcL, CBF1, CBF2, CBF3, ICE1, COR15a, and COR78 were evaluated at the end of exposure. To assess the impact of the bacteria on cell ultrastructure under low temperatures, microscopic observations were achieved. Results indicated that freezing treatment induced significant changes in PSII activity as early as the first cold day, whereas the same impact on PSII activity was observed only during the third cold night. The significant effects conferred by PsJN were differential accumulation of pigments, and reduced expression of RbcL and COR78. Microscopical observations showed an alteration/disorganization in A. thaliana leaf mesophyll cells independently of the freezing treatments. The presence of bacteria during the three successive nights or days did not significantly improved A

  4. Constitutive Modelling in Geomechanics Introduction

    CERN Document Server

    Puzrin, Alexander M

    2012-01-01

    The purpose of this book is to bridge the gap between the traditional Geomechanics and Numerical Geotechnical Modelling with applications in science and practice. Geomechanics is rarely taught within the rigorous context of Continuum Mechanics and Thermodynamics, while when it comes to Numerical Modelling, commercially available finite elements or finite differences software utilize constitutive relationships within the rigorous framework. As a result, young scientists and engineers have to learn the challenging subject of constitutive modelling from a program manual and often end up with using unrealistic models which violate the Laws of Thermodynamics.  The book is introductory, by no means does it claim any completeness and state of the art in such a dynamically developing field as numerical and constitutive modelling of soils. The author gives basic understanding of conventional continuum mechanics approaches to constitutive modelling, which can serve as a foundation for exploring more advanced theories....

  5. The Constitution's Prescription for Freedom.

    Science.gov (United States)

    Peach, Lucinda

    1986-01-01

    Examines how the framers of the Constitution came to choose our system of government, how that system was designed to function, and how the separation of powers has served to maintain our democracy despite attempts to violate it. (JDH)

  6. Jonathan's Constitutional Conference in Nigeria

    African Journals Online (AJOL)

    ian

    2013-10-01

    Oct 1, 2013 ... Adeniyi S. Basiru is an independent researcher and a PhD candidate ... constitution-making are fundamentally the exclusive reserve of the elites, ..... agenda must be situated against the background of events that heralded his.

  7. A survey on constitutional justice

    Directory of Open Access Journals (Sweden)

    Kheirollah Parvin

    2015-05-01

    Full Text Available The idea of supervising the conformity of statutory law with constitutional law, is due to necessities rooted in two essential principles: the supremacy of constitution and the hierarchy of the law. Constitution as the supreme law in the sense of status and legal value , is placed at the top of the legal pyramid of every political system and therefore requires a special organization and discipline that will act as the sanction of the principles and the main content incorporated in this legal instrument. this special organization and discipline known as Constitutional justice in legal Literature now and have studing in two main patterns. Firs pattern based on Supervision of courts on rules and other pattern is Apply by Emphasis on role of Political Institutions in Supervision on rules. This two patterns have common purpose but have different backgrounds and methods.

  8. THE EMERGING INTERNATIONAL CONSTITUTIONAL ORDER ...

    African Journals Online (AJOL)

    Dr Tanya du Plessis

    CFI) affirmed ... primarily include the value system of the international legal order, meaning norms of ... the existence of such a traditional constitutional demos. Europe's ..... between the African Development Bank (BAD) and one of its employees,.

  9. The genetic basis of constitutive and herbivore-induced ESP-independent nitrile formation in Arabidopsis.

    Science.gov (United States)

    Burow, Meike; Losansky, Anja; Müller, René; Plock, Antje; Kliebenstein, Daniel J; Wittstock, Ute

    2009-01-01

    Glucosinolates are a group of thioglucosides that are components of an activated chemical defense found in the Brassicales. Plant tissue damage results in hydrolysis of glucosinolates by endogenous thioglucosidases known as myrosinases. Spontaneous rearrangement of the aglucone yields reactive isothiocyanates that are toxic to many organisms. In the presence of specifier proteins, alternative products, namely epithionitriles, simple nitriles, and thiocyanates with different biological activities, are formed at the expense of isothiocyanates. Recently, simple nitriles were recognized to serve distinct functions in plant-insect interactions. Here, we show that simple nitrile formation in Arabidopsis (Arabidopsis thaliana) ecotype Columbia-0 rosette leaves increases in response to herbivory and that this increase is independent of the known epithiospecifier protein (ESP). We combined phylogenetic analysis, a screen of Arabidopsis mutants, recombinant protein characterization, and expression quantitative trait locus mapping to identify a gene encoding a nitrile-specifier protein (NSP) responsible for constitutive and herbivore-induced simple nitrile formation in Columbia-0 rosette leaves. AtNSP1 is one of five Arabidopsis ESP homologues that promote simple nitrile, but not epithionitrile or thiocyanate, formation. Four of these homologues possess one or two lectin-like jacalin domains, which share a common ancestry with the jacalin domains of the putative Arabidopsis myrosinase-binding proteins MBP1 and MBP2. A sixth ESP homologue lacked specifier activity and likely represents the ancestor of the gene family with a different biochemical function. By illuminating the genetic and biochemical bases of simple nitrile formation, our study provides new insights into the evolution of metabolic diversity in a complex plant defense system.

  10. Genome-Wide Analysis of PAPS1-Dependent Polyadenylation Identifies Novel Roles for Functionally Specialized Poly(A Polymerases in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Christian Kappel

    2015-08-01

    Full Text Available The poly(A tail at 3' ends of eukaryotic mRNAs promotes their nuclear export, stability and translational efficiency, and changes in its length can strongly impact gene expression. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A polymerases, PAPS1, PAPS2 and PAPS4. As shown by their different mutant phenotypes, these three isoforms are functionally specialized, with PAPS1 modifying organ growth and suppressing a constitutive immune response. However, the molecular basis of this specialization is largely unknown. Here, we have estimated poly(A-tail lengths on a transcriptome-wide scale in wild-type and paps1 mutants. This identified categories of genes as particularly strongly affected in paps1 mutants, including genes encoding ribosomal proteins, cell-division factors and major carbohydrate-metabolic proteins. We experimentally verified two novel functions of PAPS1 in ribosome biogenesis and redox homoeostasis that were predicted based on the analysis of poly(A-tail length changes in paps1 mutants. When overlaying the PAPS1-dependent effects observed here with coexpression analysis based on independent microarray data, the two clusters of transcripts that are most closely coexpressed with PAPS1 show the strongest change in poly(A-tail length and transcript abundance in paps1 mutants in our analysis. This suggests that their coexpression reflects at least partly the preferential polyadenylation of these transcripts by PAPS1 versus the other two poly(A-polymerase isoforms. Thus, transcriptome-wide analysis of poly(A-tail lengths identifies novel biological functions and likely target transcripts for polyadenylation by PAPS1. Data integration with large-scale co-expression data suggests that changes in the relative activities of the isoforms are used as an endogenous mechanism to co-ordinately modulate plant gene expression.

  11. Structure of Arabidopsis thaliana Rubisco activase.

    Science.gov (United States)

    Hasse, Dirk; Larsson, Anna M; Andersson, Inger

    2015-04-01

    The CO2-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is inactivated by the formation of dead-end complexes with inhibitory sugar phosphates. In plants and green algae, the ATP-dependent motor protein Rubisco activase restores catalytic competence by facilitating conformational changes in Rubisco that promote the release of the inhibitory compounds from the active site. Here, the crystal structure of Rubisco activase from Arabidopsis thaliana is presented at 2.9 Å resolution. The structure reveals an AAA+ two-domain structure. More than 100 residues in the protein were not visible in the electron-density map owing to conformational disorder, but were verified to be present in the crystal by mass spectrometry. Two sulfate ions were found in the structure. One was bound in the loop formed by the Walker A motif at the interface of the domains. A second sulfate ion was bound at the N-terminal end of the first helix of the C-terminal domain. The protein packs in a helical fashion in the crystal, as observed previously for Rubisco activase, but differences in the helical pitch indicate flexibility in the packing of the protein.

  12. Constitutional Verbosity and Social Trust

    DEFF Research Database (Denmark)

    Bjørnskov, Christian; Voigt, Stefan

    2014-01-01

    A common argument in the trust literature is that high-trust cultures allow efficient commercial contracts to be shorter, covering fewer contingencies. We take this idea to the topic of social contracts. Specifically, we ask whether social trust affects the length and detail of constitutions. Cross......-country estimates suggest that national trust levels are indeed robustly and negatively associated with the length of countries’ constitutions....

  13. Constitutional orders in multinational firms

    DEFF Research Database (Denmark)

    Hull Kristensen, Peer; Morgan, Glenn

    Multinationals are faced with the problem of how to coordinate different actors and stop `fiefdoms' emerging that inhibits the achievement of transnational cooperation? We identify this as a problem of `constitutional ordering' in the firm. Drawing on Varieties of Capitalism approaches, we explore...... how multinationals from different contexts seek to create constitutional orders. We argue that the models which exist appear to be destructive of coordination. We explore the implications for MNCs....

  14. Right Product, Wrong Packaging: Not 'Constitution', but 'Constitutional Charter'

    Directory of Open Access Journals (Sweden)

    John Law

    2007-05-01

    Full Text Available The article seeks to locate the principal cause of Europe’s prevailing ratification crisis in the inappropriate title arrived at in the European Convention, Treaty Establishing a Constitution for Europe. This over-ambitious styling led the media to characterise the text as simply an ‘EU Constitution’. Yet, the text was not a Constitution as we traditionally understand the term, i.e. the founding document of a State: scholars are agreed that the EU is not, and will not become upon ratification, a State.In terms of substance, whilst the text certainly strengthened some emerging constitutional aspects, it was not a major departure from the status quo like the Single European Act and Treaty on European Union had been; and it remained technically a treaty like all its predecessors. Arguably, therefore, it did not require referenda to ratify. However, confusion over the scale and importance of what was proposed, stemming from ambiguity in the title, pushed politicians down this unfortunate path.The article identifies a high level of consensus among commentators as to the true nature of the text: most are happy designating it a treaty (noun with constitutional (adjective aspects. The early proposed title Constitutional Treaty for Europe was arguably, therefore, the correct one; but it is now too late to choose this option, as the terms Constitution and Constitutional Treaty have already been muddled in debate. A more distinctive change is required. One idea could be to follow the principle employed elsewhere in the text of codifying the generally accepted but presently unwritten legal concepts of the European Court of Justice, as was done for example for ‘primacy’ and ‘direct effect’. The Court has characterised the EU treaties as a ‘constitutional charter’ for over twenty years now, and on this basis a modified title could read Treaty Establishing a Constitutional Charter for Europe. Importantly, the term ‘charter’ is recognised

  15. Haemoglobin modulates NO emission and hyponasty under hypoxia-related stress in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Hebelstrup, Kim; van Zanten, Martijn; Mandon, Julien

    2012-01-01

    Nitric oxide (NO) and ethylene are signalling molecules that are synthesized in response to oxygen depletion. Non-symbiotic plant haemoglobins (Hbs) have been demonstrated to act in roots under oxygen depletion to scavenge NO. Using Arabidopsis thaliana plants, the online emission of NO or ethylene...... was directly quantified under normoxia, hypoxia (0.1–1.0% O2), or full anoxia. The production of both gases was increased with reduced expression of either of the Hb genes GLB1 or GLB2, whereas NO emission decreased in plants overexpressing these genes. NO emission in plants with reduced Hb gene expression......-nitrosylated compounds, and it is demonstrated that hypoxia substantially increased the content of S-nitrosylated compounds. A parallel up-regulation of Hb gene expression in the normoxic shoots of the flooded plants may reflect signal transmission from root to shoot via ethylene and a role for Hb in the shoots. Hb gene...

  16. The scale of population structure in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Alexander Platt

    2010-02-01

    Full Text Available The population structure of an organism reflects its evolutionary history and influences its evolutionary trajectory. It constrains the combination of genetic diversity and reveals patterns of past gene flow. Understanding it is a prerequisite for detecting genomic regions under selection, predicting the effect of population disturbances, or modeling gene flow. This paper examines the detailed global population structure of Arabidopsis thaliana. Using a set of 5,707 plants collected from around the globe and genotyped at 149 SNPs, we show that while A. thaliana as a species self-fertilizes 97% of the time, there is considerable variation among local groups. This level of outcrossing greatly limits observed heterozygosity but is sufficient to generate considerable local haplotypic diversity. We also find that in its native Eurasian range A. thaliana exhibits continuous isolation by distance at every geographic scale without natural breaks corresponding to classical notions of populations. By contrast, in North America, where it exists as an exotic species, A. thaliana exhibits little or no population structure at a continental scale but local isolation by distance that extends hundreds of km. This suggests a pattern for the development of isolation by distance that can establish itself shortly after an organism fills a new habitat range. It also raises questions about the general applicability of many standard population genetics models. Any model based on discrete clusters of interchangeable individuals will be an uneasy fit to organisms like A. thaliana which exhibit continuous isolation by distance on many scales.

  17. Constitutional compatibility of energy systems

    International Nuclear Information System (INIS)

    Rossnagel, A.

    1983-01-01

    The paper starts from the results of the Enquiry Commission on 'Future Nuclear Energy Policy' of the 8th Federal German Parliament outlining technically feasible energy futures in four 'pathways'. For the purpose of the project, which was to establish the comparative advantages and disadvantages of different energy systems, these four scenarios were reduced to two alternatives: cases K (= nuclear energy) and S (= solar energy). The question to Ge put is: Which changes within our legal system will be ushered in by certain technological developments and how do these changes relate to the legal condition intended so far. Proceeding in this manner will not lead to the result of a nuclear energy system or a solar energy system being in conformity or in contradiction with the constitutional law, but will provide a catalogue of implications orientated to the aims of legal standards: a person deciding in favour of a nuclear energy system or a solar energy system supports this or that development of constitutional policy, and a person purishing this or that aim of legal policy should be consistent and decide in favour of this or that energy system. The investigation of constitutional compatibility leads to the question what effects different energy systems will have on the forms of political intercourse laid down in the constitutional law, which are orientated to models of a liberal constitutional tradition of citizens. (orig./HSCH) [de

  18. Small RNA-directed epigenetic natural variation in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Jixian Zhai

    2008-04-01

    Full Text Available Progress in epigenetics has revealed mechanisms that can heritably regulate gene function independent of genetic alterations. Nevertheless, little is known about the role of epigenetics in evolution. This is due in part to scant data on epigenetic variation among natural populations. In plants, small interfering RNA (siRNA is involved in both the initiation and maintenance of gene silencing by directing DNA methylation and/or histone methylation. Here, we report that, in the model plant Arabidopsis thaliana, a cluster of approximately 24 nt siRNAs found at high levels in the ecotype Landsberg erecta (Ler could direct DNA methylation and heterochromatinization at a hAT element adjacent to the promoter of FLOWERING LOCUS C (FLC, a major repressor of flowering, whereas the same hAT element in ecotype Columbia (Col with almost identical DNA sequence, generates a set of low abundance siRNAs that do not direct these activities. We have called this hAT element MPF for Methylated region near Promoter of FLC, although de novo methylation triggered by an inverted repeat transgene at this region in Col does not alter its FLC expression. DNA methylation of the Ler allele MPF is dependent on genes in known silencing pathways, and such methylation is transmissible to Col by genetic crosses, although with varying degrees of penetrance. A genome-wide comparison of Ler and Col small RNAs identified at least 68 loci matched by a significant level of approximately 24 nt siRNAs present specifically in Ler but not Col, where nearly half of the loci are related to repeat or TE sequences. Methylation analysis revealed that 88% of the examined loci (37 out of 42 were specifically methylated in Ler but not Col, suggesting that small RNA can direct epigenetic differences between two closely related Arabidopsis ecotypes.

  19. Adaptive diversification of growth allometry in the plant Arabidopsis thaliana.

    Science.gov (United States)

    Vasseur, François; Exposito-Alonso, Moises; Ayala-Garay, Oscar J; Wang, George; Enquist, Brian J; Vile, Denis; Violle, Cyrille; Weigel, Detlef

    2018-03-27

    Seed plants vary tremendously in size and morphology; however, variation and covariation in plant traits may be governed, at least in part, by universal biophysical laws and biological constants. Metabolic scaling theory (MST) posits that whole-organismal metabolism and growth rate are under stabilizing selection that minimizes the scaling of hydrodynamic resistance and maximizes the scaling of resource uptake. This constrains variation in physiological traits and in the rate of biomass accumulation, so that they can be expressed as mathematical functions of plant size with near-constant allometric scaling exponents across species. However, the observed variation in scaling exponents calls into question the evolutionary drivers and the universality of allometric equations. We have measured growth scaling and fitness traits of 451 Arabidopsis thaliana accessions with sequenced genomes. Variation among accessions around the scaling exponent predicted by MST was correlated with relative growth rate, seed production, and stress resistance. Genomic analyses indicate that growth allometry is affected by many genes associated with local climate and abiotic stress response. The gene with the strongest effect, PUB4 , has molecular signatures of balancing selection, suggesting that intraspecific variation in growth scaling is maintained by opposing selection on the trade-off between seed production and abiotic stress resistance. Our findings suggest that variation in allometry contributes to local adaptation to contrasting environments. Our results help reconcile past debates on the origin of allometric scaling in biology and begin to link adaptive variation in allometric scaling to specific genes. Copyright © 2018 the Author(s). Published by PNAS.

  20. EXPRESS

    International Nuclear Information System (INIS)

    Ancelin, C.; Le, P.; DeSaint-Quentin, S.; Villatte, N.

    1987-01-01

    This paper presents EXPRESS, an expert system developed for the automation of reliability studies. The first part consists in the description of the method for static thermohydraulic systems. In this step, the authors define the knowledge representation based on the two inference engines - ALOUETTE and LCR developed by EDF. They explain all the process to construct a fault tree from a topological and functional description of the system. Numerous examples are exhibited in illustration of the method. This is followed by the lessons derived from the studies performed on some safety systems of the PALUEL nuclear plant. The development of the same approach for electric power systems is described, insisting on the difference resulting from the sequential nature of these systems. Finally, they show the main advantages identified during the studies

  1. Arabidopsis thaliana gonidialess A/Zuotin related factors (GlsA/ZRF) are essential for maintenance of meristem integrity.

    Science.gov (United States)

    Guzmán-López, José Alfredo; Abraham-Juárez, María Jazmín; Lozano-Sotomayor, Paulina; de Folter, Stefan; Simpson, June

    2016-05-01

    Observation of a differential expression pattern, including strong expression in meristematic tissue of an Agave tequilana GlsA/ZRF ortholog suggested an important role for this gene during bulbil formation and developmental changes in this species. In order to better understand this role, the two GlsA/ZFR orthologs present in the genome of Arabidopsis thaliana were functionally characterized by analyzing expression patterns, double mutant phenotypes, promoter-GUS fusions and expression of hormone related or meristem marker genes. Patterns of expression for A. thaliana show that GlsA/ZFR genes are strongly expressed in SAMs and RAMs in mature plants and developing embryos and double mutants showed multiple changes in morphology related to both SAM and RAM tissues. Typical double mutants showed stunted growth of aerial and root tissue, formation of multiple ectopic meristems and effects on cotyledons, leaves and flowers. The KNOX genes STM and BP were overexpressed in double mutants whereas CLV3, WUSCHEL and AS1 were repressed and lack of AtGlsA expression was also associated with changes in localization of auxin and cytokinin. These results suggest that GlsA/ZFR is an essential component of the machinery that maintains the integrity of SAM and RAM tissue and underline the potential to identify new genes or gene functions based on observations in non-model plants.

  2. Constitutionalism and Development in Nigeria: The 1999 Constitution

    African Journals Online (AJOL)

    Fr. Ikenga

    the 3 arms of government the Executive, Legislative, Judiciary, Public Service and Marketing .... Rotation principle of a presidency position in Nigeria which will cultivate a sense of ... the issues survived inclusion in the 1999 Constitution of the Federal Republic of Nigeria. 13. S. 2 of Decree No. ..... Oxford, 5th Edition p.245.

  3. The Spanish Constitution, the Constitutional Court and the Catalan Referendum

    DEFF Research Database (Denmark)

    Abat Ninet, Antoni

    2015-01-01

    and politeia that Aristotle defined now clashes between two powerful symbolic and romantic phenomena. In the Spanish-Catalan binomial scenario, there are some elements that need to be analysed to obtain a complete picture of the constitutional possibilities to of accommodating a Catalan self...

  4. Time and constitution of sense

    Directory of Open Access Journals (Sweden)

    Pedro Gerardo Acosta

    2014-06-01

    Full Text Available This article proposes a reflection over our time-consciousness under the Phenomenology of Edmund Husserl. The idea is make a release the key role of the sense constitution like the fundament and development of the ongoing intentionality, a shape that make the possibility to catch sight of the sense of every life situation like conscience experience that displays itself over the time, and open the world of the Phenomenon World, constituted in the flux and flow of our live experience. The immanent time in which the things served in a lived-present inevitably displays to its own immediate-past of retentions, then of commemorations, constituting and enabling, not just the sense of ever present, but the sense of our own past like memory and our future like expectative. This reflection is based and supporter over the text “Phenomenology Lesson of the Internal Time-Consiusness” (Husserl, 2002.

  5. Demographic history of european populations of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Olivier François

    2008-05-01

    Full Text Available The model plant species Arabidopsis thaliana is successful at colonizing land that has recently undergone human-mediated disturbance. To investigate the prehistoric spread of A. thaliana, we applied approximate Bayesian computation and explicit spatial modeling to 76 European accessions sequenced at 876 nuclear loci. We find evidence that a major migration wave occurred from east to west, affecting most of the sampled individuals. The longitudinal gradient appears to result from the plant having spread in Europe from the east approximately 10,000 years ago, with a rate of westward spread of approximately 0.9 km/year. This wave-of-advance model is consistent with a natural colonization from an eastern glacial refugium that overwhelmed ancient western lineages. However, the speed and time frame of the model also suggest that the migration of A. thaliana into Europe may have accompanied the spread of agriculture during the Neolithic transition.

  6. A Communicatively Constituted Online Crisis

    DEFF Research Database (Denmark)

    Valentini, Chiara; Romenti, Stefania; Kruckeberg, Dean

    2017-01-01

    into specific public crisis perceptions. Drawing from a communicative constitution perspective, the authors argue that if crises are perceptions or experiences of difficult situations that exceed a person’s current resources and coping mechanisms, and if perceptions and experiences in social media are typically...... by offering suggestions on how to study online critical conversations through the lens of a communicative constitution perspective that could inform how critical issues eventually transform and become crises and how crisis perceptions evolve and are discursively shaped by communicative practices occurring...

  7. Constitutional and acquired autosomal aneuploidy.

    Science.gov (United States)

    Jackson-Cook, Colleen

    2011-12-01

    Chromosomal imbalances can result from numerical or structural anomalies. Numerical chromosomal abnormalities are often referred to as aneuploid conditions. This article focuses on the occurrence of constitutional and acquired autosomal aneuploidy in humans. Topics covered include frequency, mosaicism, phenotypic findings, and etiology. The article concludes with a consideration of anticipated advances that might allow for the development of screening tests and/or lead to improvements in our understanding and management of the role that aneuploidy plays in the aging process and acquisition of age-related and constitutional conditions.

  8. Reconstruction and analysis of nutrient-induced phosphorylation networks in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Guangyou eDuan

    2013-12-01

    Full Text Available Elucidating the dynamics of molecular processes in living organisms in response to external perturbations is a central goal in modern systems biology. We investigated the dynamics of protein phosphorylation events in Arabidopsis thaliana exposed to changing nutrient conditions. Phosphopeptide expression levels were detected at five consecutive time points over a time interval of 30 minutes after nutrient resupply following prior starvation. The three tested inorganic, ionic nutrients NH4+, NO3-, PO43- elicited similar phosphosignaling responses that were distinguishable from those invoked by the sugars mannitol, sucrose. When embedded in the protein-protein interaction network of Arabidopsis thaliana, phosphoproteins were found to exhibit a higher degree compared to average proteins. Based on the time-series data, we reconstructed a network of regulatory interactions mediated by phosphorylation. The performance of different network inference methods was evaluated by the observed likelihood of physical interactions within and across different subcellular compartments and based on gene ontology semantic similarity. The dynamic phosphorylation network was then reconstructed using a Pearson correlation method with added directionality based on partial variance differences. The topology of the inferred integrated network corresponds to an information dissemination architecture, in which the phosphorylation signal is passed on to an increasing number of phosphoproteins stratified into an initiation, processing, and effector layer. Specific phosphorylation peptide motifs associated with the distinct layers were identified indicating the action of layer-specific kinases. Despite the limited temporal resolution, combined with information on subcellular location, the available time-series data proved useful for reconstructing the dynamics of the molecular signaling cascade in response to nutrient stress conditions in the plant Arabidopsis thaliana.

  9. Introduction of tri-antennary N-glycans in Arabidopsis thaliana plants.

    Science.gov (United States)

    Nagels, Bieke; Van Damme, Els J M; Callewaert, Nico; Weterings, Koen

    2012-04-01

    Because the pathway for protein synthesis is largely conserved between plants and animals, plants provide an attractive platform for the cost effective and flexible production of biopharmaceuticals. However, there are some differences in glycosylation between plants and humans that need to be considered before plants can be used as an efficient expression platform. In the presented research the human genes encoding α1,3-mannosyl-β1,4-N-acetylglucosaminyltransferase (GnT-IV) and α1,6-mannosyl-β1,6-N-acetylglucosaminyltransferase (GnT-V) were introduced in the fast cycling model plant Arabidopsis thaliana to synthesize tri-antennary N-glycans. The GnT-IV and -V enzymes were targeted to the Golgi apparatus with plant-specific localization signals. The experiments were performed both in a wild type background, as well as in plants lacking β1,2-xylosyltransferase (XylT) and α1,3-fucosyltransferase (FucT) activity. Glycan analysis of endogenous proteins in the transgenic lines using CE-LIF showed that tri-antennary N-glycans could be produced in the XylT/FucT deficient line, while these structures were not found in the wild type background. Since β-N-acetylhexosaminidases, that remove terminal GlcNAcs, are active in A. thaliana plants, the specificity of these enzymes for different GlcNAc linkages was tested. The results showed that there is no pronounced preference of the A. thaliana hexosaminidases for human-type GlcNAc-linkages. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Comparative metabolic profiling of Haberlea rhodopensis, Thellungiella halophyla, and Arabidopsis thaliana exposed to low temperature

    Directory of Open Access Journals (Sweden)

    Maria eBenina

    2013-12-01

    Full Text Available Haberlea rhodopensis is a resurrection species with extreme resistance to drought stress and desiccation but also with ability to withstand low temperatures and freezing stress. In order to identify biochemical strategies which contribute to Haberlea’s remarkable stress tolerance, the metabolic reconfiguration of H. rhodopensis during low temperature (4°C and subsequent return to optimal temperatures was investigated and compared with that of the stress tolerant Thellungiella halophyla and the stress sensitive A. thaliana. The effect of the low temperature treatment in the three species was confirmed by gene expression of low-temperature- and dehydration-inducible genes. Metabolic analysis by GC-MS revealed intrinsic differences in the metabolite levels of the three species even at 21°C. H. rhodopensis had significantly more raffinose, melibiose, trehalose, myo-inositol, sorbitol, and galactinol than the other two species. A. thaliana had the highest levels of putrescine and fumarate, while T. halophila had much higher levels of several amino acids, including alanine, asparagine, beta-alanine, histidine, isoleucine, phenylalanine, serine, threonine, and valine. In addition, the three species responded differently to the low temperature treatment and the subsequent recovery, especially with regard to the sugar metabolism. Chilling induced accumulation of maltose in Haberlea and raffinose in A. thaliana, but raffinose levels in low temperature exposed Arabidopsis were still much lower than these in unstressed Haberlea. While all species accumulated sucrose during chilling, that accumulation was transient in Haberlea and Arabidopsis but sustained in T. halophila after the return to optimal temperature. In T. halophila, the levels of proline and hydroxyproline drastically increased upon recovery. Collectively, these results show inherent. differences in the metabolomes under the ambient temperature and the strategies to respond to low

  11. New Constitutionalism for Biosiversity vs. Neoconstitutionalism of Risk

    Directory of Open Access Journals (Sweden)

    Michele Carducci

    2016-08-01

    Full Text Available http://dx.doi.org/10.5007/2177-7055.2016v37n73p255 Based on an “eco-systemic” democracy that seeks to preserve biodiversity through the recognition of the co-evolutionary link between nature and culture, the Andean Constitutionalism emerges as the expression of a counter-hegemonic constitutionalism committed to the construction of a new institutional framework through the inclusion of new participatory and intercultural mechanisms. Departing from western constitutional paradigms, this groundbreaking constitutionalism revisits the “Gaia hypothesis” and legitimizes a real “social contract” among the people and nature, and instead of considering it as an “object” of ownership, exploitation, or conservation, it regards nature as a legal “subject” and primary source of society itself and the Constitution as its “legal grantor and protector”.

  12. Purifying selection acts on coding and non-coding sequences of paralogous genes in Arabidopsis thaliana.

    Science.gov (United States)

    Hoffmann, Robert D; Palmgren, Michael

    2016-06-13

    Whole-genome duplications in the ancestors of many diverse species provided the genetic material for evolutionary novelty. Several models explain the retention of paralogous genes. However, how these models are reflected in the evolution of coding and non-coding sequences of paralogous genes is unknown. Here, we analyzed the coding and non-coding sequences of paralogous genes in Arabidopsis thaliana and compared these sequences with those of orthologous genes in Arabidopsis lyrata. Paralogs with lower expression than their duplicate had more nonsynonymous substitutions, were more likely to fractionate, and exhibited less similar expression patterns with their orthologs in the other species. Also, lower-expressed genes had greater tissue specificity. Orthologous conserved non-coding sequences in the promoters, introns, and 3' untranslated regions were less abundant at lower-expressed genes compared to their higher-expressed paralogs. A gene ontology (GO) term enrichment analysis showed that paralogs with similar expression levels were enriched in GO terms related to ribosomes, whereas paralogs with different expression levels were enriched in terms associated with stress responses. Loss of conserved non-coding sequences in one gene of a paralogous gene pair correlates with reduced expression levels that are more tissue specific. Together with increased mutation rates in the coding sequences, this suggests that similar forces of purifying selection act on coding and non-coding sequences. We propose that coding and non-coding sequences evolve concurrently following gene duplication.

  13. [Constitutional mismatch repair deficiency syndrome

    NARCIS (Netherlands)

    Jongmans, M.C.J.; Gidding, C.E.M.; Loeffen, J.; Wesseling, P.; Mensenkamp, A.; Hoogerbrugge, N.

    2015-01-01

    BACKGROUND: Constitutional mismatch repair deficiency (CMMR-D) syndrome is characterised by a significantly increased risk for developing cancer in childhood. It arises when both parents have a mutation in the same mismatch repair gene and pass it on to their child. CASE DESCRIPTION: An 8-year-old

  14. The Constitution and Academic Freedom.

    Science.gov (United States)

    Gilbertson, Eric R.

    During the past 150 years U.S. courts have demonstrated a special protectiveness toward academics and academic institutions. Academic freedom was not a concern when the U.S. Constitution and the First Amendment were drafted and is not mentioned in the "Federalist Papers." However, decisions by a series of Supreme Court justices led to…

  15. Arabidopsis thaliana resistance to fusarium oxysporum 2 implicates tyrosine-sulfated peptide signaling in susceptibility and resistance to root infection.

    Directory of Open Access Journals (Sweden)

    Yunping Shen

    2013-05-01

    Full Text Available In the plant Arabidopsis thaliana, multiple quantitative trait loci (QTLs, including RFO2, account for the strong resistance of accession Columbia-0 (Col-0 and relative susceptibility of Taynuilt-0 (Ty-0 to the vascular wilt fungus Fusarium oxysporum forma specialis matthioli. We find that RFO2 corresponds to diversity in receptor-like protein (RLP genes. In Col-0, there is a tandem pair of RLP genes: RFO2/At1g17250 confers resistance while RLP2 does not. In Ty-0, the highly diverged RFO2 locus has one RLP gene conferring weaker resistance. While the endogenous RFO2 makes a modest contribution to resistance, transgenic RFO2 provides strong pathogen-specific resistance. The extracellular leucine-rich repeats (eLRRs in RFO2 and RLP2 are interchangeable for resistance and remarkably similar to eLRRs in the receptor-like kinase PSY1R, which perceives tyrosine-sulfated peptide PSY1. Reduced infection in psy1r and mutants of related phytosulfokine (PSK receptor genes PSKR1 and PSKR2 shows that tyrosine-sulfated peptide signaling promotes susceptibility. The related eLRRs in RFO2 and PSY1R are not interchangeable; and expression of the RLP nPcR, in which eLRRs in RFO2 are replaced with eLRRs in PSY1R, results in constitutive resistance. Counterintuitively, PSY1 signaling suppresses nPcR because psy1r nPcR is lethal. The fact that PSK signaling does not similarly affect nPcR argues that PSY1 signaling directly downregulates the expression of nPcR. Our results support a speculative but intriguing model to explain RFO2's role in resistance. We propose that F. oxysporum produces an effector that inhibits the normal negative feedback regulation of PSY1R, which stabilizes PSY1 signaling and induces susceptibility. However, RFO2, acting as a decoy receptor for PSY1R, is also stabilized by the effector and instead induces host immunity. Overall, the quantitative resistance of RFO2 is reminiscent of the better-studied monogenic resistance traits.

  16. Towards annotating the plant epigenome: the Arabidopsis thaliana small RNA locus map.

    Science.gov (United States)

    Hardcastle, Thomas J; Müller, Sebastian Y; Baulcombe, David C

    2018-04-20

    Based on 98 public and internal small RNA high throughput sequencing libraries, we mapped small RNAs to the genome of the model organism Arabidopsis thaliana and defined loci based on their expression using an empirical Bayesian approach. The resulting loci were subsequently classified based on their genetic and epigenetic context as well as their expression properties. We present the results of this classification, which broadly conforms to previously reported divisions between transcriptional and post-transcriptional gene silencing small RNAs, and to PolIV and PolV dependencies. However, we are able to demonstrate the existence of further subdivisions in the small RNA population of functional significance. Moreover, we present a framework for similar analyses of small RNA populations in all species.

  17. Dehydrin from citrus, which confers in vitro dehydration and freezing protection activity, is constitutive and highly expressed in the flavedo of fruit but responsive to cold and water stress in leaves.

    Science.gov (United States)

    Sanchez-Ballesta, Maria Teresa; Rodrigo, Maria Jesus; Lafuente, Maria Teresa; Granell, Antonio; Zacarias, Lorenzo

    2004-04-07

    A cDNA encoding a dehydrin was isolated from the flavedo of the chilling-sensitive Fortune mandarin fruit (Citrus clementina Hort. Ex Tanaka x Citrus reticulata Blanco) and designed as Crcor15. The predicted CrCOR15 protein is a K2S member of a closely related dehydrin family from Citrus, since it contains two tandem repeats of the unusual Citrus K-segment and one S-segment (serine cluster) at an unusual C-terminal position. Crcor15 mRNA is consistently and highly expressed in the flavedo during fruit development and maturation. The relative abundance of Crcor15 mRNA in the flavedo was estimated to be higher than 1% of total RNA. The high mRNA level remained unchanged during fruit storage at chilling (2 degrees C) and nonchilling (12 degrees C) temperatures, and it was depressed by a conditioning treatment (3 days at 37 degrees C) that induced chilling tolerance. Therefore, the expression of Crcor15 appears not to be related to the acquisition of chilling tolerance in mandarin fruits. However, Crcor15, which was barely detected in unstressed mandarin leaves, was rapidly induced in response to both low temperature and water stress. COR15 protein was expressed in Escherichia coli, and the purified protein conferred in vitro protection against freezing and dehydration inactivation. The potential role of Citrus COR15 is discussed.

  18. Transcriptional and metabolomic analysis of Ascophyllum nodosum mediated freezing tolerance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Nair Prasanth

    2012-11-01

    Full Text Available Abstract Background We have previously shown that lipophilic components (LPC of the brown seaweed Ascophyllum nodosum (ANE improved freezing tolerance in Arabidopsis thaliana. However, the mechanism(s of this induced freezing stress tolerance is largely unknown. Here, we investigated LPC induced changes in the transcriptome and metabolome of A. thaliana undergoing freezing stress. Results Gene expression studies revealed that the accumulation of proline was mediated by an increase in the expression of the proline synthesis genes P5CS1 and P5CS2 and a marginal reduction in the expression of the proline dehydrogenase (ProDH gene. Moreover, LPC application significantly increased the concentration of total soluble sugars in the cytosol in response to freezing stress. Arabidopsis sfr4 mutant plants, defective in the accumulation of free sugars, treated with LPC, exhibited freezing sensitivity similar to that of untreated controls. The 1H NMR metabolite profile of LPC-treated Arabidopsis plants exposed to freezing stress revealed a spectrum dominated by chemical shifts (δ representing soluble sugars, sugar alcohols, organic acids and lipophilic components like fatty acids, as compared to control plants. Additionally, 2D NMR spectra suggested an increase in the degree of unsaturation of fatty acids in LPC treated plants under freezing stress. These results were supported by global transcriptome analysis. Transcriptome analysis revealed that LPC treatment altered the expression of 1113 genes (5% in comparison with untreated plants. A total of 463 genes (2% were up regulated while 650 genes (3% were down regulated. Conclusion Taken together, the results of the experiments presented in this paper provide evidence to support LPC mediated freezing tolerance enhancement through a combination of the priming of plants for the increased accumulation of osmoprotectants and alteration of cellular fatty acid composition.

  19. Study of genes induced by ionizing radiations at Arabidopsis thaliana: identification and molecular characterization of the ATGR1 gene, a new gene encoding a protein involved in plant cell division

    International Nuclear Information System (INIS)

    Deveaux, Yves

    1999-01-01

    DNA damage, that can be experimentally introduced by ionizing radiation (IR), induces complex signal transduction pathways leading to cell recovery or, alternatively to programmed cell death if damages are too severe. To identify the inducible components of the response to genotoxic stress in plants, we have screened by Differential Display for mRNAs that rapidly and strongly accumulate after IR treatment in A. thaliana cells. We have characterized ATGR1, a new single copy Arabidopsis gene encoding a PEST-box protein of unknown function. In unstressed plant organs the ATGR1 mRNA is hardly detectable, whereas the protein is present in extracts prepared from roots, shoot meristems and inflorescences, that all contain large amounts of actively dividing cells. This pattern is confirmed by immuno localisation on tissue sections that shows constitutive ATGR1 protein expression covering the root elongation zone, the shoot meristem, leaf primordial and the ovules of developing flowers. Histochemical analysis of transgenic plants expressing the GUS reporter gene under the control of the ATGR1 promoter, demonstrate that the developmental and tissue-specific profile of ATGR1 protein expression is conferred by the gene promoter. The massive, transient and dose-dependent accumulation of ATGR1 transcripts after IR treatment observed in all plant organs does not lead to significant changes in ATGR1 protein pattern. Stable ATGR1 protein overexpression, as exemplified by transgenic A. thaliana plants that contain a 35S promoter-ATGR1 gene fusion, does not induce notable changes of the overall ATGR1 protein level, but leads to male and female sterility. The cause of sterility is a lack of correct chromosome assembly and distribution at the stage metaphase II of meiosis. Taken together our results show that i) ATGR1 gene expression is associated to cell division during plant development ii) the ATGR1 protein level is regulated at the transcriptional and post-transcriptional level iii

  20. Contested constitutions: Legitimacy of constitution-making and constitutional conflict in Central Europe

    NARCIS (Netherlands)

    de Raadt, J.B.

    2009-01-01

    What were the effects of constitution-making procedures on the acceptance of the new "rules of the political game" in postcommunist Central Europe? This article sets out to scrutinise the increasingly popular claim among politicians and scholars of democratisation that inclusiveness and popular

  1. Sensitivity of two ecotypes of Arabidopsis Thaliana (Cvi and Te) towards UV-B irradiation

    International Nuclear Information System (INIS)

    Velichkova, M.; Stanoeva, D.; Popova, A.

    2013-01-01

    he susceptibility of Arabidopsis thaliana towards the detrimental effect of UV-B irradiation was investigated using two ecotypes, Cvi and Te. The effect of UV-B treatment on primary photosynthetic reactions - energy interaction between the main pigment-protein complexes and oxygen evolution, was evaluated at low (4 0 C) and at room (22 0 C) temperature. UV-B-induced alterations of investigated photosynthetic reactions are better expressed at 22 0 C than at 4 0 C for Cvi. For Te ecotype the energy interaction was suppressed to higher extent at 22 0 C, while oxygen evolving activity was affected similarly at both temperatures. At low and room temperature, the energy interaction in the complex PSII-core antenna is affected stronger by UV-B treatment than the energy distribution between both photosystems, as revealed by fluorescence ratios of 77 K spectra. The results presented indicate that the Arabidopsis thaliana ecotype Cvi (Cape Verde Islands) is less affected by UV-B irradiation in respect to the investigated primary photosynthetic reactions than the ecotype Te (Finland)

  2. Valuation In The Constitutional Era

    Directory of Open Access Journals (Sweden)

    Elmien du Plessis

    2015-12-01

    Full Text Available The Constitution brought about a new compensation regime for expropriations. Compensation for expropriation must now be "just and equitable". Whereas before the Constitution came into force market value played a central role in compensation for expropriation, market value is now only one factor or aspect of compensation that the court needs to take into account. Yet we find that courts tend to focus on market value and to still employ the valuation methods used to calculate market value. This article argues that the methods used to calculate the market value, once thought to be objective, are not as objective as was believed. While it is impossible to give judges specific tools for the assessment of market value, this article provides guidelines on how the calculation of compensation should be approached.

  3. The Constitutive Power of Twitter

    DEFF Research Database (Denmark)

    Albu, Oana Brindusa; Etter, Michael Andreas

    Twitter is an increasingly used new information and communication technology (ICT) in organizational settings. Predominant research, however, tends to adopt functionalist standpoints and investigates new ICTs as platforms of information transmission through which organizations interact with their......Twitter is an increasingly used new information and communication technology (ICT) in organizational settings. Predominant research, however, tends to adopt functionalist standpoints and investigates new ICTs as platforms of information transmission through which organizations interact...... with their constituents. Such focus leaves little knowledge concerning the tensions new ICTs bring to organizational life. For a more nuanced understanding of the constitutive role of new ICTs in organizing, this paper unfolds a communication centered perspective and examines the strategic Twitter use in two...... organizations. The analysis illustrates how specific Twitter interactions, i.e., hashtags, become hypertexts—a type of authoritative texts—which simultaneously constitute an organizational actor or act as a pastiche of it. The study contributes to extant research by illustrating how hypertextuality...

  4. Highlights of meiotic genes in Arabidopsis thaliana | Consiglio ...

    African Journals Online (AJOL)

    Meiosis is a fascinating and complex phenomenon and, despite its central role in sexual plant reproduction, little is known on the molecular mechanisms involved in this process. We review the progress made in recent years using Arabidopsis thaliana mutants for isolating meiotic genes. In particular, emphasis is given on ...

  5. Adaptation of Arabidopsis thaliana to the Yangtze River basin.

    Science.gov (United States)

    Zou, Yu-Pan; Hou, Xing-Hui; Wu, Qiong; Chen, Jia-Fu; Li, Zi-Wen; Han, Ting-Shen; Niu, Xiao-Min; Yang, Li; Xu, Yong-Chao; Zhang, Jie; Zhang, Fu-Min; Tan, Dunyan; Tian, Zhixi; Gu, Hongya; Guo, Ya-Long

    2017-12-28

    Organisms need to adapt to keep pace with a changing environment. Examining recent range expansion aids our understanding of how organisms evolve to overcome environmental constraints. However, how organisms adapt to climate changes is a crucial biological question that is still largely unanswered. The plant Arabidopsis thaliana is an excellent system to study this fundamental question. Its origin is in the Iberian Peninsula and North Africa, but it has spread to the Far East, including the most south-eastern edge of its native habitats, the Yangtze River basin, where the climate is very different. We sequenced 118 A. thaliana strains from the region surrounding the Yangtze River basin. We found that the Yangtze River basin population is a unique population and diverged about 61,409 years ago, with gene flows occurring at two different time points, followed by a population dispersion into the Yangtze River basin in the last few thousands of years. Positive selection analyses revealed that biological regulation processes, such as flowering time, immune and defense response processes could be correlated with the adaptation event. In particular, we found that the flowering time gene SVP has contributed to A. thaliana adaptation to the Yangtze River basin based on genetic mapping. A. thaliana adapted to the Yangtze River basin habitat by promoting the onset of flowering, a finding that sheds light on how a species can adapt to locales with very different climates.

  6. Changes in leaf proteome profile of Arabidopsis thaliana in ...

    Indian Academy of Sciences (India)

    2013-04-25

    Apr 25, 2013 ... Changes in leaf proteome profile of Arabidopsis thaliana in response to salicylic ... ethylene (ET) plays a key role in plant defence response by controlling ..... Oryza sativa. ( japonica cultivar-group). 24. 33.855/5.85. RT8702.

  7. Uptake and metabolism of sulphur dioxide by Arabidopsis thaliana

    NARCIS (Netherlands)

    van der Kooij, T.A.W.; De Kok, L.J.; Haneklaus, S.; Schnug, E.

    Arabidopsis thaliana (L.) Heynh. was exposed to various concentrations of SO2 during almost the entire life cycle. No negative effects of SO2 on shoot biomass production were observed. There was a linear relation between the deposition of SO2 and the atmospheric SO2 concentration. Sulphur

  8. Cleaning the GenBank Arabidopsis thaliana data set

    DEFF Research Database (Denmark)

    Korning, Peter G.; Hebsgaard, Stefan M.; Rouze, Pierre

    1996-01-01

    Data driven computational biology relies on the large quantities of genomic data stored in international sequence data banks. However, the possibilities are drastically impaired if the stored data is unreliable. During a project aiming to predict splice sites in the dicot Arabidopsis thaliana, we...... through anonymous FTP....

  9. The influences of Hygromycin B on growth of Arabidopsis thaliana ...

    African Journals Online (AJOL)

    In this article, growth and development of Arabidopsis thaliana seedling cotyledon and leaf were evidently affected by Hygromycin B. As compared to the control, cotyledon of seedling on Murashige and Skoog (MS) with Hygromycin B was very small and its leaf was not formed. Along with increase in culture time, cells in the ...

  10. Reduction of mineral nutrient availability accelerates flowering of Arabidopsis thaliana

    Czech Academy of Sciences Publication Activity Database

    Kolář, Jan; Seňková, J.

    2008-01-01

    Roč. 165, č. 15 (2008), s. 1601-1609 ISSN 0176-1617 R&D Projects: GA AV ČR KJB600380510 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arabidopsis thaliana * Flowering * Landsberg erecta Subject RIV: EF - Botanics Impact factor: 2.437, year: 2008

  11. [Women, gender, and the Constitution].

    Science.gov (United States)

    1993-12-01

    Although all the constitutions of Latin America directly or indirectly acknowledge the juridical equality of the sexes, these patriarchal societies continue to maintain institutional power in male hands and to neutralize legal actions favoring women. International instruments such as the Convention on Elimination of All Forms of Discrimination Against Women, approved by the UN in 1979, have given a firmer basis to policies and actions to improve the status of women. Obstacles to full equality of Latin American women are rooted in economic and sociopolitical factors, but lack of true political will also plays a significant role. A number of new laws in the past several years as well as the new Constitution have improved the legal position of Colombian women. The new Constitution recognizes fundamental rights that may be claimed directly before a judge, and social, economic, and collective rights requiring legislative development. Article 43 of the new Constitution states that women will not be subjected to any form of discrimination. Another norm states that women will enjoy special assistance and protection before and after childbirth, in recognition of the social functions of maternity. Article 43 also states that women who are heads of households will receive special assistance, but the corresponding regulations have not yet been promulgated. The mechanism of tutelage has become an important recourse that has been used in several cases in which fundamental rights of women have been violated or threatened because of their sex. The order of tutelage has been used in cases of adolescents expelled from school for pregnancy and of abused wives, as well as to force recognition of the social and economic contributions of housework.

  12. European constitution and EURATOM treaty

    International Nuclear Information System (INIS)

    Heller, W.

    2003-01-01

    The European Council held in Laeken in December 2001 had decided to call a convention preparing the next conference of the heads of state and government which, among other topics, was to deliberate the question of a fully formulated European constitution. Under the presidency of Giscard d'Estaing, all delegates to the European Convention on July 10, 2003 signed the draft treaty for a European constitution. This final document is the basis of the conference of the heads of state and government to begin in October 2003. On this occasion, the draft of a separate chapter on energy could well come up again for examination. This chapter had been introduced only at the end of the deliberations of the convention and adds to the competences of the EU institutions. Also the Euratom Treaty was a topic of the convention preparing the constitution. As the presidency felt that no specific issues had been raised in the Laeken declaration, it is proposed to adapt the Euratom Treaty to the new provisions of the constitution by adding a protocol. This would mean that the European Atomic Energy Community, for the time being, would retain its independent legal status. The contents would have to be examined at some later date. Consequently, the real discussion of the Euratom Treaty is yet to come. Also, the speedy completion of the single market for electricity would make it desirable for the Community to adopt a uniform, positive stance in the use of nuclear power at the best possible safety standards so as to ensure a level playing field. Current events entailing power failures in the United States and the United Kingdom have alerted the public to the problem of the continuity of power supply. This could well be the beginning of a new, unbiased, balanced energy discussion in a bigger Europe. (orig.)

  13. Voltage-Dependent Anion Channel 2 of Arabidopsis thaliana (AtVDAC2 Is Involved in ABA-Mediated Early Seedling Development

    Directory of Open Access Journals (Sweden)

    Xufeng Li

    2009-05-01

    Full Text Available The voltage-dependent anion channel (VDAC is the major transport protein in the outer membrane of mitochondria and plays crucial roles in energy metabolism, apoptosis, and metabolites transport. In plants, the expression of VDACs can be affected by different stresses, including drought, salinity and pathogen defense. In this study, we investigated the expression pattern of AtVDAC2 in A. thaliana and found ABA suppressed the accumulation of AtVDAC2 transcripts. Further, phenotype analysis of this VDAC deregulated-expression transgenic Arabidopsis plants indicated that AtVDAC2 anti-sense line showed an ABA-insensitivity phenotype during the early seedling development under ABA treatment. The results suggested that AtVDAC2 might be involved in ABA signaling in A. thaliana.

  14. Molecular evolutionary analysis of the Alfin-like protein family in Arabidopsis lyrata, Arabidopsis thaliana, and Thellungiella halophila.

    Directory of Open Access Journals (Sweden)

    Yu Song

    Full Text Available In previous studies, the Alfin1 gene, a transcription factor, enhanced salt tolerance in alfalfa, primarily through altering gene expression levels in the root. Here, we examined the molecular evolution of the Alfin-like (AL proteins in two Arabidopsis species (A. lyrata and A. thaliana and a salt-tolerant close relative Thellungiella halophila. These AL-like proteins could be divided into four groups and the two known DUF3594 and PHD-finger domains had co-evolved within each group of genes, irrespective of species, due to gene duplication events in the common ancestor of all three species while gene loss was observed only in T. halophila. To detect whether natural selection acted in the evolution of AL genes, we calculated synonymous substitution ratios (dn/ds and codon usage statistics, finding positive selection operated on four branches and significant differences in biased codon usage in the AL family between T. halophila and A. lyrata or A. thaliana. Distinctively, only the AL7 branch was under positive selection on the PHD-finger domain and the three members on the branch showed the smallest difference when codon bias was evaluated among the seven clusters. Functional analysis based on transgenic overexpression lines and T-DNA insertion mutants indicated that salt-stress-induced AtAL7 could play a negative role in salt tolerance of A. thaliana, suggesting that adaptive evolution occurred in the members of AL gene family.

  15. Evaluation of the plant growth-promoting activity of Pseudomonas nitroreducens in Arabidopsis thaliana and Lactuca sativa.

    Science.gov (United States)

    Trinh, Cao Son; Lee, Hyeri; Lee, Won Je; Lee, Seok Jin; Chung, Namhyun; Han, Juhyeong; Kim, Jongyun; Hong, Suk-Whan; Lee, Hojoung

    2018-06-01

    Pseudomonas nitroreducens: strain IHB B 13561 (PnIHB) enhances the growth of Arabidopsis thaliana and Lactuca sativa via the stimulation of cell development and nitrate absorption. Plant growth-promoting rhizobacteria (PGPR) enhance plant development through various mechanisms; they improve the uptake of soil resources by plants to greatly promote plant growth. Here, we used Arabidopsis thaliana seedlings and Lactuca sativa to screen the growth enhancement activities of a purified PGPR, Pseudomonas nitroreducens strain IHB B 13561 (PnIHB). When cocultivated with PnIHB, both species of plants exhibited notably improved growth, particularly in regard to biomass. Quantitative reverse transcription polymerase chain reaction analysis indicated high expression levels of the nitrate transporter genes, especially NRT2.1, which plays a major role in the high-affinity nitrate transport system in roots. Moreover, enhanced activity of the cyclin-B1 promoter was observed when wild-type 'Columbia-0' Arabidopsis seedlings were exposed to PnIHB, whereas upregulation of cyclin-B also occurred in the inoculated lettuce seedlings. Overall, these results suggest that PnIHB improves A. thaliana and L. sativa growth via specific pathways involved in the promotion of cell development and enhancement of nitrate uptake.

  16. Constitutional collisions of criminal law

    Directory of Open Access Journals (Sweden)

    Sergey M. Inshakov

    2016-12-01

    Full Text Available Objective to identify and resolve conflicts between the norms of constitutional and criminal law which regulate the issue of legal liability of senior officials of the state. Methods formallogical systematic comparativelegal. Results the article analyzes the embodiment of the principle of citizensrsquo equality under the law regarding the criminal responsibility of the President of the Russian Federation as one of the segments of the elite right other criminal and legal conflicts are considered associated with the creation of conditions for derogation from the principle of equality. Basing on this analysis the means of overcoming collisions between the norms of constitutional and criminal law are formulated. Scientific novelty in the article for the first time it has been shown that in the Russian criminal law there are exceptions to the principle of citizensrsquo equality under the law relating to the President of the Russian Federation the conflicts are identified between the norms of constitutional and criminal law regulating the issue of legal liability of senior officials of the state ways of overcoming conflicts are suggested. Practical significance the main provisions and conclusions of the article can be used in research and teaching in the consideration of issues of senior state officialsrsquo criminal liability.

  17. The roles of genetic drift and natural selection in quantitative trait divergence along an altitudinal gradient in Arabidopsis thaliana.

    Science.gov (United States)

    Luo, Y; Widmer, A; Karrenberg, S

    2015-02-01

    Understanding how natural selection and genetic drift shape biological variation is a central topic in biology, yet our understanding of the agents of natural selection and their target traits is limited. We investigated to what extent selection along an altitudinal gradient or genetic drift contributed to variation in ecologically relevant traits in Arabidopsis thaliana. We collected seeds from 8 to 14 individuals from each of 14 A. thaliana populations originating from sites between 800 and 2700 m above sea level in the Swiss Alps. Seed families were grown with and without vernalization, corresponding to winter-annual and summer-annual life histories, respectively. We analyzed putatively neutral genetic divergence between these populations using 24 simple sequence repeat markers. We measured seven traits related to growth, phenology and leaf morphology that are rarely reported in A. thaliana and performed analyses of altitudinal clines, as well as overall QST-FST comparisons and correlation analyses among pair-wise QST, FST and altitude of origin differences. Multivariate analyses suggested adaptive differentiation along altitude in the entire suite of traits, particularly when expressed in the summer-annual life history. Of the individual traits, a decrease in rosette leaf number in the vegetative state and an increase in leaf succulence with increasing altitude could be attributed to adaptive divergence. Interestingly, these patterns relate well to common within- and between-species trends of smaller plant size and thicker leaves at high altitude. Our results thus offer exciting possibilities to unravel the underlying mechanisms for these conspicuous trends using the model species A. thaliana.

  18. MiRNA-513a-5p inhibits progesterone receptor expression and constitutes a risk factor for breast cancer: the hOrmone and Diet in the ETiology of breast cancer prospective study.

    Science.gov (United States)

    Muti, Paola; Donzelli, Sara; Sacconi, Andrea; Hossain, Ahmed; Ganci, Federica; Frixa, Tania; Sieri, Sabina; Krogh, Vittorio; Berrino, Franco; Biagioni, Francesca; Strano, Sabrina; Beyene, Joseph; Yarden, Yosef; Blandino, Giovanni

    2018-02-09

    MicroRNAs (miRNAs) might be considered both predictors and players of cancer development. The aim of the present report was to investigate whether many years before the diagnosis of breast cancer miRNA expression is already disregulated. In order to test this hypothesis, we compared miRNAs extracted from leukocytes in healthy women who later developed breast cancer and in women who remain healthy during the whole 15-year follow-up time. Accordantly, we used a case-control study design nested in the hOrmone and Diet in the ETiology of breast cancer (ORDET) prospective cohort study addressing the possibility that miRNAs can serve as both early biomarkers and components of the hormonal etiological pathways leading to breast cancer development in premenopausal women. We compared leukocyte miRNA profiles of 191 incident premenopausal breast cancer cases and profiles of 191 women who remained healthy over a follow-up period of 20 years. The analysis identified 20 differentially expressed miRNAs in women candidate to develop breast cancer versus control women. The upregulated miRNAs, miR-513-a-5p, miR-513b-5p and miR-513c-5p were among the most significantly deregulated miRNAs. In multivariate analysis, miR-513a-5p upregulation was directly and statistically significant associated with breast cancer risk (OR = 1.69; 95% CI 1.08-2.64; P = 0.0293). In addition, the upregulation of miR-513-a-5p displayed the strongest direct association with serum progesterone and testosterone levels. The experimental data corroborated the inhibitory function of miR-513a-5p on progesterone receptor expression confirming that progesterone receptor is a target of miR-513a-5p. The identification of upregulated miR-513a-5p with its oncogenic potential further validates the use of miRNAs as long-term biomarker of breast cancer risk. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Molecular signatures in Arabidopsis thaliana in response to insect attack and bacterial infection.

    Directory of Open Access Journals (Sweden)

    Pankaj Barah

    Full Text Available BACKGROUND: Under the threat of global climatic change and food shortages, it is essential to take the initiative to obtain a comprehensive understanding of common and specific defence mechanisms existing in plant systems for protection against different types of biotic invaders. We have implemented an integrated approach to analyse the overall transcriptomic reprogramming and systems-level defence responses in the model plant species Arabidopsis thaliana (A. thaliana henceforth during insect Brevicoryne brassicae (B. brassicae henceforth and bacterial Pseudomonas syringae pv. tomato strain DC3000 (P. syringae henceforth attacks. The main aim of this study was to identify the attacker-specific and general defence response signatures in A. thaliana when attacked by phloem-feeding aphids or pathogenic bacteria. RESULTS: The obtained annotated networks of differentially expressed transcripts indicated that members of transcription factor families, such as WRKY, MYB, ERF, BHLH and bZIP, could be crucial for stress-specific defence regulation in Arabidopsis during aphid and P. syringae attack. The defence response pathways, signalling pathways and metabolic processes associated with aphid attack and P. syringae infection partially overlapped. Components of several important biosynthesis and signalling pathways, such as salicylic acid (SA, jasmonic acid (JA, ethylene (ET and glucosinolates, were differentially affected during the two the treatments. Several stress-regulated transcription factors were known to be associated with stress-inducible microRNAs. The differentially regulated gene sets included many signature transcription factors, and our co-expression analysis showed that they were also strongly co-expressed during 69 other biotic stress experiments. CONCLUSIONS: Defence responses and functional networks that were unique and specific to aphid or P. syringae stresses were identified. Furthermore, our analysis revealed a probable link between

  20. Constitutive expression of the K-domain of a Vaccinium corymbosum SOC1-like (VcSOC1-K) MADS-box gene is sufficient to promote flowering in tobacco.

    Science.gov (United States)

    Song, Guo-qing; Walworth, Aaron; Zhao, Dongyan; Hildebrandt, Britton; Leasia, Michael

    2013-11-01

    The K-domain of a blueberry-derived SOC1 -like gene promotes flowering in tobacco without negatively impacting yield, demonstrating potential for manipulation of flowering time in horticultural crops. The SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) and SOC1-likes, belonging to the MIKC(c) (type II) MADS-box gene subfamily, are major floral activators and integrators of plant flowering. Both MADS-domains and K (Keratin)-domains are highly conserved in MIKC(c)-type MADS proteins. While there are many reports on overexpression of intact MIKC(c)-type MADS-box genes, few studies have been conducted to investigate the effects of the K-domains. In this report, a 474-bp K-domain of Vaccinium SOC1-like (VcSOC1-K) was cloned from the cDNA library of the northern highbush blueberry (Vaccinium corymbosum L.). Functional analysis of the VcSOC1-K was conducted by ectopically expressing of 35S:VcSOC1-K in tobacco. Reverse transcription PCR confirmed expression of the VcSOC1-K in T0 plants. Phenotypically, T1 transgenic plants (10 T1 plants/event) flowered sooner after seeding, and were shorter with fewer leaves at the time of flowering, than nontransgenic plants; but seed pod production of transgenic plants was not significantly affected. These results demonstrate that overexpression of the K-domain of a MIKC(c)-type MADS-box gene alone is sufficient to promote early flowering and more importantly without affecting seed production.

  1. Variations in constitutive and inducible UV-B tolerance; dissecting photosystem II protection in Arabidopsis thaliana accessions

    NARCIS (Netherlands)

    Jansen, M.A.K.; LeMartret, B.; Koornneef, M.

    2010-01-01

    The rise in ultraviolet-B (UV-B) (280–315 nm) radiation levels, that is a consequence of stratospheric ozone layer depletion, has triggered extensive research on the effects of UV-B on plants. Plants raised under natural sunlight conditions are generally well protected from the potentially harmful

  2. Both the constitutive Cauliflower Mosaic Virus 35S and tissue-specific AGAMOUS enhancers activate transcription autonomously in Arabidopsis thaliana

    Science.gov (United States)

    The presence of multiple enhancers and promoters within a single vector often provokes complicated mutual interaction and crosstalk, thereby, altering promoter specificity, which causes serious problems for precisely engineering gene function and agronomic traits in transgenic plants. Enhancer elem...

  3. Non-coplanar polychlorinated biphenyls (PCBs) are direct agonists for the human pregnane-X receptor and constitutive androstane receptor, and activate target gene expression in a tissue-specific manner

    International Nuclear Information System (INIS)

    Al-Salman, Fadheela; Plant, Nick

    2012-01-01

    The polychlorinated biphenyl group possesses high environmental persistence, leading to bioaccumulation and a number of adverse effects in mammals. Whilst coplanar PCBs elicit their toxic effects through agonism of the aryl hydrocarbon receptor; however, non-coplanar PCBs are not ligands for AhR, but may be ligands for members of the nuclear receptor family of proteins. To better understand the biological actions of non-coplanar PCBs, we have undertaken a systematic analysis of their ability to activate PXR and CAR-mediated effects. Cells were exposed to a range of non-coplanar PCBs (99, 138, 153, 180 and 194), or the coplanar PCB77: Direct activation of PXR and CAR was measured using a mammalian receptor activation assay in human liver cells, with rifampicin and CITCO used as positive controls ligands for PXR and CAR, respectively; activation of target gene expression was examined using reporter gene plasmids for CYP3A4 and MDR1 transfected into liver, intestine and lung cell lines. Several of the non-coplanar PCBs directly activated PXR and CAR, whilst the coplanar PCB77 did not. Non-coplanar PCBs were also able to activate PXR/CAR target gene expression in a substitution- and tissue-specific manner. Non-coplanar PCBs act as direct activators for the nuclear receptors PXR and CAR, and are able to elicit transcriptional activation of target genes in a substitution- and tissue-dependent manner. Chronic activation of PXR/CAR is linked to adverse effects and must be included in any risk assessment of PCBs. -- Highlights: ► Several Non-coplanar PCBs are able to directly activate both PXR and CAR in vitro. ► PCB153 is the most potent direct activator of PXR and CAR nuclear receptors. ► Non-coplanar PCB activation of CYP3A4/MDR1 reporter genes is structure-dependent. ► Non-coplanar PCB activate CYP3A4/MDR1 reporter genes in a tissue-dependent. ► PCB153 is the most potent activator of PXR/CAR target gene in all tissues.

  4. Genetic Analysis of Gravity Signal Transduction in Arabidopsis thaliana Seedlings

    Science.gov (United States)

    Boonsirichai, K.; Harrison, B.; Stanga, J.; Young, L.-S.; Neal, C.; Sabat, G.; Murthy, N.; Harms, A.; Sedbrook, J.; Masson, P.

    The primary roots of Arabidopsis thaliana seedlings respond to gravity stimulation by developing a tip curvature that results from differential cellular elongation on opposite flanks of the elongation zone. This curvature appears modulated by a lateral gradient of auxin that originates in the gravity-perceiving cells (statocytes) of the root cap through an apparent lateral repositioning of a component the auxin efflux carrier complex within these cells (Friml et al, 2002, Nature 415: 806-809). Unfortunately, little is known about the molecular mechanisms that govern early phases of gravity perception and signal transduction within the root-cap statocytes. We have used a molecular genetic approach to uncover some of these mechanisms. Mutations in the Arabidopsis ARG1 and ARL2 genes, which encode J-domain proteins, resulted in specific alterations in root and hypocotyl gravitropism, without pleiotropic phenotypes. Interestingly, ARG1 and ARL2 appear to function in the same genetic pathway. A combination of molecular genetic, biochemical and cell-biological approaches were used to demonstrate that ARG1 functions in early phases of gravity signal transduction within the root and hypocotyl statocytes, and is needed for efficient lateral auxin transport within the cap. The ARG1 protein is associated with components of the secretory and/or endosomal pathways, suggesting its role in the recycling of components of the auxin efflux carrier complex between plasma membrane and endosome (Boonsirichai et al, 2003, Plant Cell 15:2612-2625). Genetic modifiers of arg1-2 were isolated and shown to enhance the gravitropic defect of arg1-2, while resulting in little or no gravitropic defects in a wild type ARG1 background. A slight tendency for arg1-2;mar1-1 and arg1-2;mar2-1 double-mutant organs to display an opposite gravitropic response compared to wild type suggests that all three genes contribute to the interpretation of the gravity-vector information by seedling organs. The

  5. The Normative Constitution of Agency

    OpenAIRE

    Korsgaard, Christine M.

    2014-01-01

    On a naturalistic conception of agency, someone is an agent when certain of his own mental states are the cause of his movements. On a normative conception, a person constitutes his agency by following certain principles or laws. In Kant’s conception, for example, a movement counts as the agent’s own when it is chosen autonomously, that is, in accordance with the categorical imperative. To say that someone acts is to imply that his movements are a manifestation of his own activity and that it...

  6. Phenotypical and molecular responses of Arabidopsis thaliana roots as a result of inoculation with the auxin-producing bacterium Azospirillum brasilense.

    Science.gov (United States)

    Spaepen, Stijn; Bossuyt, Stijn; Engelen, Kristof; Marchal, Kathleen; Vanderleyden, Jos

    2014-02-01

    The auxin-producing bacterium Azospirillum brasilense Sp245 can promote the growth of several plant species. The model plant Arabidopsis thaliana was chosen as host plant to gain an insight into the molecular mechanisms that govern this interaction. The determination of differential gene expression in Arabidopsis roots after inoculation with either A. brasilense wild-type or an auxin biosynthesis mutant was achieved by microarray analysis. Arabidopsis thaliana inoculation with A. brasilense wild-type increases the number of lateral roots and root hairs, and elevates the internal auxin concentration in the plant. The A. thaliana root transcriptome undergoes extensive changes on A. brasilense inoculation, and the effects are more pronounced at later time points. The wild-type bacterial strain induces changes in hormone- and defense-related genes, as well as in plant cell wall-related genes. The A. brasilense mutant, however, does not elicit these transcriptional changes to the same extent. There are qualitative and quantitative differences between A. thaliana responses to the wild-type A. brasilense strain and the auxin biosynthesis mutant strain, based on both phenotypic and transcriptomic data. This illustrates the major role played by auxin in the Azospirillum-Arabidopsis interaction, and possibly also in other bacterium-plant interactions. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  7. BoALMT1, an Al-Induced Malate Transporter in Cabbage, Enhances Aluminum Tolerance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2018-01-01

    Full Text Available Aluminum (Al is present in approximately 50% of the arable land worldwide and is regarded as the main limiting factor of crop yield on acidic soil. Al-induced root malate efflux plays an important role in the Al tolerance of plants. Here, the aluminum induced malate transporter BoALMT1 (KF322104 was cloned from cabbage (Brassica oleracea. BoALMT1 showed higher expression in roots than in shoots. The expression of BoALMT1 was specifically induced by Al treatment, but not the trivalent cations lanthanum (La, cadmium (Cd, zinc (Zn, or copper (Cu. Subcellular localization studies were performed in onion epidermal cells and revealed that BoALMT1 was localized at the plasma membrane. Scanning Ion-selective Electrode Technique was used to analyze H+ flux. Xenopus oocytes and Arabidopsis thaliana expressing BoALMT1 excreted more H+ under Al treatment. Overexpressing BoALMT1 in transgenic Arabidopsis resulted in enhanced Al tolerance and increased malate secretion. The results suggested that BoALMT1 functions as an Al-resistant gene and encodes a malate transporter. Expressing BoALMT1 in Xenopus oocytes or A. thaliana indicated that BoALMT1 could increase malate secretion and H+ efflux to resist Al tolerance.

  8. Essence and constitution in Zubiri

    Directory of Open Access Journals (Sweden)

    Alfonso Gómez Fernández

    2015-03-01

    Full Text Available The aim of this article is to expound Zubiri’s concept of essence and to begin a critical discussion and evaluation of his proposal. Before explaining what essence is, it is necessary to observe that, for our author, not all things have an essence: only «reality-things» but not «meaning-things» form part of the «essentiable domain». This distinction between «reality-things» and «meaning-things» supposes a new conception of nature. (Nature is not the opposite of the artificial, as the Greek term physis is.«Reality-things» form a constitutional and «closed» system of non-causal and non-«external» characteristics or traits. These «foundational characteristics» of constitution, then, are precisely the essence. The article discusses critically the assumptions of this doctrine (reality, ontological pluralism, foundation and its possible limits in the light of contemporary science. It can be a useful theory for the philosophy of language.

  9. Spatiotemporal relationships between growth and microtubule orientation as revealed in living root cells of Arabidopsis thaliana transformed with green-fluorescent-protein gene construct GFP-MBD

    Science.gov (United States)

    Granger, C. L.; Cyr, R. J.

    2001-01-01

    Arabidopsis thaliana plants were transformed with GFP-MBD (J. Marc et al., Plant Cell 10: 1927-1939, 1998) under the control of a constitutive (35S) or copper-inducible promoter. GFP-specific fluorescence distributions, levels, and persistence were determined and found to vary with age, tissue type, transgenic line, and individual plant. With the exception of an increased frequency of abnormal roots of 35S GFP-MBD plants grown on kanamycin-containing media, expression of GFP-MBD does not appear to affect plant phenotype. The number of leaves, branches, bolts, and siliques as well as overall height, leaf size, and seed set are similar between wild-type and transgenic plants as is the rate of root growth. Thus, we conclude that the transgenic plants can serve as a living model system in which the dynamic behavior of microtubules can be visualized. Confocal microscopy was used to simultaneously monitor growth and microtubule behavior within individual cells as they passed through the elongation zone of the Arabidopsis root. Generally, microtubules reoriented from transverse to oblique or longitudinal orientations as growth declined. Microtubule reorientation initiated at the ends of the cell did not necessarily occur simultaneously in adjacent neighboring cells and did not involve complete disintegration and repolymerization of microtubule arrays. Although growth rates correlated with microtubule reorientation, the two processes were not tightly coupled in terms of their temporal relationships, suggesting that other factor(s) may be involved in regulating both events. Additionally, microtubule orientation was more defined in cells whose growth was accelerating and less stringent in cells whose growth was decelerating, indicating that microtubule-orienting factor(s) may be sensitive to growth acceleration, rather than growth per se.

  10. Light responses in Photoperiodism in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Anthony R. Cashmore

    2006-08-01

    B. Nature 410, 487-490. Jarillo, J. A., Gabrys, H., Capel, J., Alonso, J. M., Ecker, J. R., and Cashmore, A. R. (2001b). Phototropin-related NPL1 controls chloroplast relocation induced by blue light. Nature 410, 952-954. Kinoshita, T., Doi, M., Suetsugu, N., Kagawa, T., Wada, M., and Shimazaki Ki, K. (2001). phot1 and phot2 mediate blue light regulation of stomatal opening. Nature 414, 656-660. Mas, P., Kim, W. Y., Somers, D. E., and Kay, S. A. (2003). Targeted degradation of TOC1 by ZTL modulates circadian function in Arabidopsis thaliana. Nature 426, 567-570.

  11. Excess boron responsive regulations of antioxidative mechanism at physio-biochemical and molecular levels in Arabidopsis thaliana.

    Science.gov (United States)

    Kayıhan, Doğa Selin; Kayıhan, Ceyhun; Çiftçi, Yelda Özden

    2016-12-01

    This work was aimed to evaluate the effect of boron (B) toxicity on oxidative damage level, non-enzymatic antioxidant accumulation such as anthocyanin, flavonoid and proline and expression levels of antioxidant enzymes including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and glutathione reductase (GR) and their respective activities as well as expression levels of miR398 and miR408 in Arabidopsis thaliana. Plants were germinated and grown on MS medium containing 1 mM B (1B) and 3 mM B (3B) for 14 d. Toxic B led to a decrease of photosynthetic pigments and an increase in accumulation of total soluble and insoluble sugars in accordance with phenotypically viewed chlorosis of seedlings through increasing level of B concentration. Along with these inhibitions, a corresponding increase in contents of flavonoid, anthocyanin and proline occurred that provoked oxidative stress tolerance. 3B caused a remarkable increase in total SOD activity whereas the activities of APX, GR and CAT remained unchanged as verified by expected increase in H 2 O 2 content. In contrast to GR, the coincidence was found between the expressions of SOD and APX genes and their respective activities. 1B induced mir398 expression, whereas 3B did not cause any significant change in expression of mir408 and mir398. Expression levels of GR genes were coordinately regulated with DHAR2 expression. Moreover, the changes in expression level of MDAR2 was in accordance with changes in APX6 expression and total APX activity, indicating fine-tuned regulation of ascorbate-glutathione cycle which might trigger antioxidative responses against B toxicity in Arabidopsis thaliana. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Infection and RNA recombination of Brome mosaic virus in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Dzianott, Aleksandra; Bujarski, Jozef J.

    2004-01-01

    Ecotypes of Arabidopsis thaliana supported the replication and systemic spread of Brome mosaic virus (BMV) RNAs. Infection was induced either by manual inoculation with viral RNA or by BMV virions, demonstrating that virus disassembly did not prevent infection. When in vitro-transcribed BMV RNAs 1-3 were used, production of subgenomic RNA4 was observed, showing that BMV RNA replication and transcription had occurred. Furthermore, inoculations of the transgenic Arabidopsis line that expressed a suppressor of RNA interference (RNAi) pathway markedly increased the BMV RNA concentrations. Inoculations with designed BMV RNA3 recombination vectors generated both homologous and nonhomologous BMV RNA-RNA recombinants. Thus, all cellular factors essential for BMV RNA replication, transcription, and RNA recombination were shown to be present in Arabidopsis. The current scope of understanding of the model Arabidopsis plant system should facilitate the identification of these factors governing the BMV life cycle

  13. Gene introduction into the mitochondria of Arabidopsis thaliana via peptide-based carriers

    Science.gov (United States)

    Chuah, Jo-Ann; Yoshizumi, Takeshi; Kodama, Yutaka; Numata, Keiji

    2015-01-01

    Available methods in plant genetic transformation are nuclear and plastid transformations because similar procedures have not yet been established for the mitochondria. The double membrane and small size of the organelle, in addition to its large population in cells, are major obstacles in mitochondrial transfection. Here we report the intracellular delivery of exogenous DNA localized to the mitochondria of Arabidopsis thaliana using a combination of mitochondria-targeting peptide and cell-penetrating peptide. Low concentrations of peptides were sufficient to deliver DNA into the mitochondria and expression of imported DNA reached detectable levels within a short incubation period (12 h). We found that electrostatic interaction with the cell membrane is not a critical factor for complex internalization, instead, improved intracellular penetration of mitochondria-targeted complexes significantly enhanced gene transfer efficiency. Our results delineate a simple and effective peptide-based method, as a starting point for the development of more sophisticated plant mitochondrial transfection strategies.

  14. Identification of a novel group of putative Arabidopsis thaliana beta-(1,3)-galactosyltransferases

    DEFF Research Database (Denmark)

    Qu, Yongmei; Egelund, Jack; Gilson, Paul R

    2008-01-01

    To begin biochemical and molecular studies on the biosynthesis of the type II arabinogalactan chains on arabinogalactan-proteins (AGPs), we adopted a bioinformatic approach to identify and systematically characterise the putative galactosyltransferases (GalTs) responsible for synthesizing the beta......-(1,3)-Gal linkage from CAZy GT-family-31 from Arabidopsis thaliana. These analyses confirmed that 20 members of the GT-31 family contained domains/motifs typical of biochemically characterised beta-(1,3)-GTs from mammalian systems. Microarray data confirm that members of this family are expressed......,3)-GalT activity. This bioinformatic/molecular study of CAZy GT-family-31 was validated by the recent report of Strasser et al. (Plant Cell 19:2278-2292, 2007) that another member of this family (At1g26810; GALT1) encodes a beta-(1,3)-GalT involved in the biosynthesis of the Lewis a epitope of N...

  15. Transcriptomic variation among six Arabidopsis thaliana accessions identified several novel genes controlling aluminium tolerance.

    Science.gov (United States)

    Kusunoki, Kazutaka; Nakano, Yuki; Tanaka, Keisuke; Sakata, Yoichi; Koyama, Hiroyuki; Kobayashi, Yuriko

    2017-02-01

    Differences in the expression levels of aluminium (Al) tolerance genes are a known determinant of Al tolerance among plant varieties. We combined transcriptomic analysis of six Arabidopsis thaliana accessions with contrasting Al tolerance and a reverse genetic approach to identify Al-tolerance genes responsible for differences in Al tolerance between accession groups. Gene expression variation increased in the signal transduction process under Al stress and in growth-related processes in the absence of stress. Co-expression analysis and promoter single nucleotide polymorphism searching suggested that both trans-acting polymorphisms of Al signal transduction pathway and cis-acting polymorphisms in the promoter sequences caused the variations in gene expression associated with Al tolerance. Compared with the wild type, Al sensitivity increased in T-DNA knockout (KO) lines for five genes, including TARGET OF AVRB OPERATION1 (TAO1) and an unannotated gene (At5g22530). These were identified from 53 Al-inducible genes showing significantly higher expression in tolerant accessions than in sensitive accessions. These results indicate that the difference in transcriptional signalling is partly associated with the natural variation in Al tolerance in Arabidopsis. Our study also demonstrates the feasibility of comparative transcriptome analysis by using natural genetic variation for the identification of genes responsible for Al stress tolerance. © 2016 John Wiley & Sons Ltd.

  16. Multiple BiP genes of Arabidopsis thaliana are required for male gametogenesis and pollen competitiveness.

    Science.gov (United States)

    Maruyama, Daisuke; Sugiyama, Tomoyuki; Endo, Toshiya; Nishikawa, Shuh-Ichi

    2014-04-01

    Immunoglobulin-binding protein (BiP) is a molecular chaperone of the heat shock protein 70 (Hsp70) family. BiP is localized in the endoplasmic reticulum (ER) and plays key roles in protein translocation, protein folding and quality control in the ER. The genomes of flowering plants contain multiple BiP genes. Arabidopsis thaliana has three BiP genes. BIP1 and BIP2 are ubiquitously expressed. BIP3 encodes a less well conserved BiP paralog, and it is expressed only under ER stress conditions in the majority of organs. Here, we report that all BiP genes are expressed and functional in pollen and pollen tubes. Although the bip1 bip2 double mutation does not affect pollen viability, the bip1 bip2 bip3 triple mutation is lethal in pollen. This result indicates that lethality of the bip1 bip2 double mutation is rescued by BiP3 expression. A decrease in the copy number of the ubiquitously expressed BiP genes correlates well with a decrease in pollen tube growth, which leads to reduced fitness of mutant pollen during fertilization. Because an increased protein secretion activity is expected to increase the protein folding demand in the ER, the multiple BiP genes probably cooperate with each other to ensure ER homeostasis in cells with active secretion such as rapidly growing pollen tubes.

  17. BILF1 Mediated Transformation Correlates with Constitutive Signaling

    DEFF Research Database (Denmark)

    Lyngaa, Rikke Birgitte

    2009-01-01

    BIFL1 is a G protein-coupled receptor encoded by human EBV. It signals constitutively through G_alpha_i and is an orphan receptor known to down regulate MHCI expression. BILF1 also engage in dimerization with several chemokine receptors and it induced the activity of NF-kappa beta and inhibits...

  18. Polynomial constitutive model for shape memory and pseudo elasticity

    International Nuclear Information System (INIS)

    Savi, M.A.; Kouzak, Z.

    1995-01-01

    This paper reports an one-dimensional phenomenological constitutive model for shape memory and pseudo elasticity using a polynomial expression for the free energy which is based on the classical Devonshire theory. This study identifies the main characteristics of the classical theory and introduces a simple modification to obtain better results. (author). 9 refs., 6 figs

  19. Unborn children as constitutional persons.

    Science.gov (United States)

    Roden, Gregory J

    2010-01-01

    In Roe v. Wade, the state of Texas argued that "the fetus is a 'person' within the language and meaning of the Fourteenth Amendment." To which Justice Harry Blackmun responded, "If this suggestion of personhood is established, the appellant's case, of course, collapses, for the fetus' right to life would then be guaranteed specifically by the Amendment." However, Justice Blackmun then came to the conclusion "that the word 'person,' as used in the Fourteenth Amendment, does not include the unborn." In this article, it is argued that unborn children are indeed "persons" within the language and meaning of the Fourteenth and Fifth Amendments. As there is no constitutional text explicitly holding unborn children to be, or not to be, "persons," this argument will be based on the "historical understanding and practice, the structure of the Constitution, and thejurisprudence of [the Supreme] Court." Specifically, it is argued that the Constitution does not confer upon the federal government a specifically enumerated power to grant or deny "personhood" under the Fourteenth Amendment. Rather, the power to recognize or deny unborn children as the holders of rights and duties has been historically exercised by the states. The Roe opinion and other Supreme Court cases implicitly recognize this function of state sovereignty. The states did exercise this power and held unborn children to be persons under the property, tort, and criminal law of the several states at the time Roe was decided. As an effect of the unanimity of the states in holding unborn children to be persons under criminal, tort, and property law, the text of the Equal Protection Clause of the Fourteenth Amendment compels federal protection of unborn persons. Furthermore, to the extent Justice Blackmun examined the substantive law in these disciplines, his findings are clearly erroneous and as a whole amount to judicial error. Moreover, as a matter of procedure, according to the due process standards recognized in

  20. GABA transaminases from Saccharomyces cerevisiae and Arabidopsis thaliana complement function in cytosol and mitochondria.

    Science.gov (United States)

    Cao, Juxiang; Barbosa, Jose M; Singh, Narendra; Locy, Robert D

    2013-07-01

    GABA transaminase (GABA-T) catalyses the conversion of GABA to succinate semialdehyde (SSA) in the GABA shunt pathway. The GABA-T from Saccharomyces cerevisiae (ScGABA-TKG) is an α-ketoglutarate-dependent enzyme encoded by the UGA1 gene, while higher plant GABA-T is a pyruvate/glyoxylate-dependent enzyme encoded by POP2 in Arabidopsis thaliana (AtGABA-T). The GABA-T from A. thaliana is localized in mitochondria and mediated by an 18-amino acid N-terminal mitochondrial targeting peptide predicated by both web-based utilities TargetP 1.1 and PSORT. Yeast UGA1 appears to lack a mitochondrial targeting peptide and is localized in the cytosol. To verify this bioinformatic analysis and examine the significance of ScGABA-TKG and AtGABA-T compartmentation and substrate specificity on physiological function, expression vectors were constructed to modify both ScGABA-TKG and AtGABA-T, so that they express in yeast mitochondria and cytosol. Physiological function was evaluated by complementing yeast ScGABA-TKG deletion mutant Δuga1 with AtGABA-T or ScGABA-TKG targeted to the cytosol or mitochondria for the phenotypes of GABA growth defect, thermosensitivity and heat-induced production of reactive oxygen species (ROS). This study demonstrates that AtGABA-T is functionally interchangeable with ScGABA-TKG for GABA growth, thermotolerance and limiting production of ROS, regardless of location in mitochondria or cytosol of yeast cells, but AtGABA-T is about half as efficient in doing so as ScGABA-TKG. These results are consistent with the hypothesis that pyruvate/glyoxylate-limited production of NADPH mediates the effect of the GABA shunt in moderating heat stress in Saccharomyces. Copyright © 2013 John Wiley & Sons, Ltd.

  1. Inhibition by acrolein of light-induced stomatal opening through inhibition of inward-rectifying potassium channels in Arabidopsis thaliana.

    Science.gov (United States)

    Islam, Md Moshiul; Ye, Wenxiu; Matsushima, Daiki; Khokon, Md Atiqur Rahman; Munemasa, Shintaro; Nakamura, Yoshimasa; Murata, Yoshiyuki

    2015-01-01

    Acrolein is a reactive α,β-unsaturated aldehyde derived from lipid peroxides, which are produced in plants under a variety of stress. We investigated effects of acrolein on light-induced stomatal opening using Arabidopsis thaliana. Acrolein inhibited light-induced stomatal opening in a dose-dependent manner. Acrolein at 100 μM inhibited plasma membrane inward-rectifying potassium (Kin) channels in guard cells. Acrolein at 100 μM inhibited Kin channel KAT1 expressed in a heterologous system using Xenopus leaves oocytes. These results suggest that acrolein inhibits light-induced stomatal opening through inhibition of Kin channels in guard cells.

  2. The Genetic Basis of Constitutive and Herbivore-Induced ESP-Independent Nitrile Formation in Arabidopsis1[W][OA

    Science.gov (United States)

    Burow, Meike; Losansky, Anja; Müller, René; Plock, Antje; Kliebenstein, Daniel J.; Wittstock, Ute

    2009-01-01

    Glucosinolates are a group of thioglucosides that are components of an activated chemical defense found in the Brassicales. Plant tissue damage results in hydrolysis of glucosinolates by endogenous thioglucosidases known as myrosinases. Spontaneous rearrangement of the aglucone yields reactive isothiocyanates that are toxic to many organisms. In the presence of specifier proteins, alternative products, namely epithionitriles, simple nitriles, and thiocyanates with different biological activities, are formed at the expense of isothiocyanates. Recently, simple nitriles were recognized to serve distinct functions in plant-insect interactions. Here, we show that simple nitrile formation in Arabidopsis (Arabidopsis thaliana) ecotype Columbia-0 rosette leaves increases in response to herbivory and that this increase is independent of the known epithiospecifier protein (ESP). We combined phylogenetic analysis, a screen of Arabidopsis mutants, recombinant protein characterization, and expression quantitative trait locus mapping to identify a gene encoding a nitrile-specifier protein (NSP) responsible for constitutive and herbivore-induced simple nitrile formation in Columbia-0 rosette leaves. AtNSP1 is one of five Arabidopsis ESP homologues that promote simple nitrile, but not epithionitrile or thiocyanate, formation. Four of these homologues possess one or two lectin-like jacalin domains, which share a common ancestry with the jacalin domains of the putative Arabidopsis myrosinase-binding proteins MBP1 and MBP2. A sixth ESP homologue lacked specifier activity and likely represents the ancestor of the gene family with a different biochemical function. By illuminating the genetic and biochemical bases of simple nitrile formation, our study provides new insights into the evolution of metabolic diversity in a complex plant defense system. PMID:18987211

  3. Lil3 dimerization and chlorophyll binding in Arabidopsis thaliana.

    Science.gov (United States)

    Mork-Jansson, Astrid Elisabeth; Gargano, Daniela; Kmiec, Karol; Furnes, Clemens; Shevela, Dmitriy; Eichacker, Lutz Andreas

    2015-10-07

    The two-helix light harvesting like (Lil) protein Lil3 belongs to the family of chlorophyll binding light harvesting proteins of photosynthetic membranes. A function in tetrapyrrol synthesis and stabilization of geranylgeraniol reductase has been shown. Lil proteins contain the chlorophyll a/b-binding motif; however, binding of chlorophyll has not been demonstrated. We find that Lil3.2 from Arabidopsis thaliana forms heterodimers with Lil3.1 and binds chlorophyll. Lil3.2 heterodimerization (25±7.8 nM) is favored relative to homodimerization (431±59 nM). Interaction of Lil3.2 with chlorophyll a (231±49 nM) suggests that heterodimerization precedes binding of chlorophyll in Arabidopsis thaliana. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  4. The Constitutive Values of Science

    Directory of Open Access Journals (Sweden)

    Hugh Lacey

    1997-06-01

    Full Text Available Cognitive values are the characteristics that are constitutive of good theories, the criteria to which we appeal when choosing among competing theories. I argue that, in order to count as a cognitive value, a characteristic must be needed to explain actually made theory choices, and its cognitive significance must be well defended especially in view of considerations derived from the objective of science. A number of proposed objectives of science are entertained, and it is argued that adopting a par-ticular objective is dialectically intertwined with commitment to certain social values.Then, the ways in which science is, and is not value free is explored briefly, leading to the identification of a level of analysis where values may influence theory choice without causing paradox or threatening the impartiality of soundly-made scientific judgments.

  5. [Constitutional mismatch repair deficiency syndrome].

    Science.gov (United States)

    Jongmans, Marjolijn C; Gidding, Corrie E; Loeffen, Jan; Wesseling, Pieter; Mensenkamp, Arjen; Hoogerbrugge, Nicoline

    2015-01-01

    Constitutional mismatch repair deficiency (CMMR-D) syndrome is characterised by a significantly increased risk for developing cancer in childhood. It arises when both parents have a mutation in the same mismatch repair gene and pass it on to their child. An 8-year-old girl was diagnosed with CMMR-D syndrome after she developed a brain tumour at the age of 4 and a T-cell non-Hodgkin lymphoma at the age of 6. She had multiple hyperpigmented skin lesions and died of myelodysplastic syndrome at the age of 11. In children with cancer CMMR-D syndrome can be recognized particularly if there are multiple primary malignancies and skin hyperpigmentations and hypopigmentations. The parents of these children are at high risk for colorectal and endometrial cancer (Lynch syndrome), amongst others.

  6. Kinanthropometry - Components of body constitution

    Directory of Open Access Journals (Sweden)

    Maria Tereza Silveira Böhme

    2000-12-01

    Full Text Available The objective of this study is to present the conceptual and historical background to Kinanthropometry and to characterize this area of research. The components of body constitution relating to dimensions, proportions, shape and body composition that should be considered in Physical Education and Sports programs are also described. ARESUMO Este trabalho tem por objetivo apresentar os aspectos conceituais referentes à Cineantropometria, assim como os aspectos históricos e caracterização desta área de estudos. São também descritos os componentes de constituição corporal referentes à dimensões, proporções, forma e composição corporal que devem ser considerados em programas de Educação Física e Esporte.

  7. Carbon source-sink relationship in Arabidopsis thaliana: the role of sucrose transporters.

    Science.gov (United States)

    Durand, Mickaël; Mainson, Dany; Porcheron, Benoît; Maurousset, Laurence; Lemoine, Rémi; Pourtau, Nathalie

    2018-03-01

    The regulation of source-to-sink sucrose transport is associated with AtSUC and AtSWEET sucrose transporters' gene expression changes in plants grown hydroponically under different physiological conditions. Source-to-sink transport of sucrose is one of the major determinants of plant growth. Whole-plant carbohydrates' partitioning requires the specific activity of membrane sugar transporters. In Arabidopsis thaliana plants, two families of transporters are involved in sucrose transport: AtSUCs and AtSWEETs. This study is focused on the comparison of sucrose transporter gene expression, soluble sugar and starch levels and long distance sucrose transport, in leaves and sink organs (mainly roots) in different physiological conditions (along the plant life cycle, during a diel cycle, and during an osmotic stress) in plants grown hydroponically. In leaves, the AtSUC2, AtSWEET11, and 12 genes known to be involved in phloem loading were highly expressed when sucrose export was high and reduced during osmotic stress. In roots, AtSUC1 was highly expressed and its expression profile in the different conditions tested suggests that it may play a role in sucrose unloading in roots and in root growth. The SWEET transporter genes AtSWEET12, 13, and 15 were found expressed in all organs at all stages studied, while differential expression was noticed for AtSWEET14 in roots, stems, and siliques and AtSWEET9, 10 expressions were only detected in stems and siliques. A role for these transporters in carbohydrate partitioning in different source-sink status is proposed, with a specific attention on carbon demand in roots. During development, despite trophic competition with others sinks, roots remained a significant sink, but during osmotic stress, the amount of translocated [U- 14 C]-sucrose decreased for rosettes and roots. Altogether, these results suggest that source-sink relationship may be linked with the regulation of sucrose transporter gene expression.

  8. Fertilization-independent seed development in Arabidopsis thaliana

    OpenAIRE

    Chaudhury, Abdul M.; Ming, Luo; Miller, Celia; Craig, Stuart; Dennis, Elizabeth S.; Peacock, W. James

    1997-01-01

    We report mutants in Arabidopsis thaliana (fertilization-independent seed: fis) in which certain processes of seed development are uncoupled from the double fertilization event that occurs after pollination. These mutants were isolated as ethyl methanesulfonate-induced pseudo-revertants of the pistillata phenotype. Although the pistillata (pi) mutant has short siliques devoid of seed, the fis mutants in the pi background have long siliques containing developing seeds, even though the flowers ...

  9. Functional genetics of intraspecific ecological interactions in Arabidopsis thaliana

    OpenAIRE

    Wolf, Jason B.; Mutic, Joshua J.; Kover, Paula X.

    2011-01-01

    Studying the genetic basis of traits involved in ecological interactions is a fundamental part of elucidating the connections between evolutionary and ecological processes. Such knowledge allows one to link genetic models of trait evolution with ecological models describing interactions within and between species. Previous work has shown that connections between genetic and ecological processes in Arabidopsis thaliana may be mediated by the fact that quantitative trait loci (QTL) with ‘direct...

  10. Collection of apoplastic fluids from Arabidopsis thaliana leaves

    DEFF Research Database (Denmark)

    Madsen, Svend Roesen; Nour-Eldin, Hussam Hassan; Halkier, Barbara Ann

    2016-01-01

    The leaf apoplast comprises the extracellular continuum outside cell membranes. A broad range of processes take place in the apoplast, including intercellular signaling, metabolite transport, and plant-microbe interactions. To study these processes, it is essential to analyze the metabolite conte...... in apoplastic fluids. Due to the fragile nature of leaf tissues, it is a challenge to obtain apoplastic fluids from leaves. Here, methods to collect apoplastic washing fluid and guttation fluid from Arabidopsis thaliana leaves are described....

  11. Characterization of a Cytokinin Response Factor in Arabidopsis thaliana

    OpenAIRE

    Ketelsen, Bernd

    2012-01-01

    The papers of this thesis are not available in Munin: 1. Bernd Ketelsen, Rainer Schwacke, Kirsten Krause and Karsten Fischer: 'Transcriptional activation by Cytokinin Response Factor 5 is governed by an acidic Cterminus containing two conserved domains' (manuscript) 2. Bernd Ketelsen, Stian Olsen, Kirsten Krause and Karsten Fischer: 'Cytokinin responsive factor 5 (CRF5) is involved in root development, hormonal crosstalk and sugar metabolism in Arabidopsis thaliana' (manuscript) 3. Bernd K...

  12. The Obligations on Government and Society in our Constitutional State to Respect and Support Independent Constitutional Structures

    Directory of Open Access Journals (Sweden)

    LWH Ackermann

    2000-05-01

    must be independent. Its members cannot be elected, because that would imply that the Court owed allegiance or were accountable to the political majority or other elector in question. On the other hand, it is seen as undemocratic for a body that is not elected to be in a position to overrule the expressed will of the political representatives of the majority. This paradox exists in respect of all our courts and makes the method of appointing judicial officers particularly important in order to ensure at the same time, and as far as this is practically possible, both their independence and their legitimacy. The judiciary is however not an arm of the state that has been exempted from all checks and balances. The checks and balances on the judiciary are not the same as in the case of the legislature and the executive. In the case of the latter the checks and balances are principally through the Constitution, as enforced by the courts, and through the political process. In the case of the courts these checks and balances cannot be through the political process, for this would undermine the independence of the judiciary. One of the reciprocal obligations that a constitutional democracy imposes on all its subjects, is to support the independent constitutional institutions, as constitutional institutions, not only vocally at the level of intellectual abstraction, but by actively working to establish the habits of consitutionalism in all societal structures and societal interaction

  13. Similar Pathogen Targets in Arabidopsis thaliana and Homo sapiens Protein Networks

    Science.gov (United States)

    2012-09-21

    Similar Pathogen Targets in Arabidopsis thaliana and Homo sapiens Protein Networks Paulo Shakarian1*, J. Kenneth Wickiser2 1 Paulo Shakarian...significantly attacked. Citation: Shakarian P, Wickiser JK (2012) Similar Pathogen Targets in Arabidopsis thaliana and Homo sapiens Protein Networks...to 00-00-2012 4. TITLE AND SUBTITLE Similar Pathogen Targets in Arabidopsis thaliana and Homo sapiens Protein Networks 5a. CONTRACT NUMBER 5b

  14. Constitutive and ligand-induced TCR degradation

    DEFF Research Database (Denmark)

    von Essen, Marina; Bonefeld, Charlotte Menné; Siersma, Volkert

    2004-01-01

    Modulation of TCR expression levels is a central event during T cell development and activation, and it probably plays an important role in adjusting T cell responsiveness. Conflicting data have been published on down-regulation and degradation rates of the individual TCR subunits, and several di...... to the lysosomes. Similar results were obtained in studies of primary human Vbeta8+ T cells stimulated with superantigen. Based on these results, the simplest model for TCR internalization, sorting, and degradation is proposed.......Modulation of TCR expression levels is a central event during T cell development and activation, and it probably plays an important role in adjusting T cell responsiveness. Conflicting data have been published on down-regulation and degradation rates of the individual TCR subunits, and several...... divergent models for TCR down-regulation and degradation have been suggested. The aims of this study were to determine the rate constants for constitutive and ligand-induced TCR degradation and to determine whether the TCR subunits segregate or are processed as an intact unit during TCR down...

  15. Conservation, diversification and expansion of C2H2 zinc finger proteins in the Arabidopsis thaliana genome

    Directory of Open Access Journals (Sweden)

    Böhm Siegfried

    2004-07-01

    Full Text Available Background The classical C2H2 zinc finger domain is involved in a wide range of functions and can bind to DNA, RNA and proteins. The comparison of zinc finger proteins in several eukaryotes has shown that there is a lot of lineage specific diversification and expansion. Although the number of characterized plant proteins that carry the classical C2H2 zinc finger motifs is growing, a systematic classification and analysis of a plant genome zinc finger gene set is lacking. Results We found through in silico analysis 176 zinc finger proteins in Arabidopsis thaliana that hence constitute the most abundant family of putative transcriptional regulators in this plant. Only a minority of 33 A. thaliana zinc finger proteins are conserved in other eukaryotes. In contrast, the majority of these proteins (81% are plant specific. They are derived from extensive duplication events and form expanded families. We assigned the proteins to different subgroups and families and focused specifically on the two largest and evolutionarily youngest families (A1 and C1 that are suggested to be primarily involved in transcriptional regulation. The newly defined family A1 (24 members comprises proteins with tandemly arranged zinc finger domains. Family C1 (64 members, earlier described as the EPF-family in Petunia, comprises proteins with one isolated or two to five dispersed fingers and a mostly invariant QALGGH motif in the zinc finger helices. Based on the amino acid pattern in these helices we could describe five different signature sequences prevalent in C1 zinc finger domains. We also found a number of non-finger domains that are conserved in these families. Conclusions Our analysis of the few evolutionarily conserved zinc finger proteins of A. thaliana suggests that most of them could be involved in ancient biological processes like RNA metabolism and chromatin-remodeling. In contrast, the majority of the unique A. thaliana zinc finger proteins are known or

  16. A three-dimensional constitutive model for shape memory alloy

    International Nuclear Information System (INIS)

    Zhou, Bo; Yoon, Sung-Ho; Leng, Jin-Song

    2009-01-01

    Shape memory alloy (SMA) has a wide variety of practical applications due to its unique super-elasticity and shape memory effect. It is of practical interest to establish a constitutive model which predicts its phase transformation and mechanical behaviors. In this paper, a new three-dimensional phase transformation equation, which predicts the phase transformation behaviors of SMA, is developed based on the results of a differential scanning calorimetry (DSC) test. It overcomes both limitations: that Zhou's phase transformation equations fail to describe the phase transformation from twinned martensite to detwinned martensite of SMA and Brinson's phase transformation equation fails to express the influences of phase transformation peak temperatures on the phase transformation behaviors of SMA. A new three-dimensional constitutive equation, which predicts the mechanical behaviors associated with the super-elasticity and shape memory effect of SMA, is developed on the basis of thermodynamics and solid mechanics. Results of numerical simulations show that the new constitutive model, which includes the new phase transformation equation and constitutive equation, can predict the phase transformation and mechanical behaviors associated with the super-elasticity and shape memory effect of SMA precisely and comprehensively. It is proved that Brinson's constitutive model of SMA can be considered as one special case of the new constitutive model

  17. Constitutional Principles of State Control in the Republic of Armenia

    Directory of Open Access Journals (Sweden)

    Gabriel K. Balayan

    2015-12-01

    Full Text Available In the present article some of the provision of the RA Constitution’s basic principles of state control, which, in my opinion, should be guided by regulatory authorities during the inspection are discussed. These principles are considered by the author as the basis of the constitutionality of state control. Some of the control principles are divided by the author into positive and negative. Positive defines the principles that provide the freedom of action of man and citizen. Negative same principles are for government agencies, since they restrict their activities. A separate analysis is subject to the presidency on the basis of the principle of separation and balance of powers. In conclusion, author concludes that, based on the interpretation of the constitutional principles discussed, the term "law" applies only to natural and legal persons on the other hand can not be used as an analogue of the terms "authority" and "authority." According to the author, the fundamental constitutional principles of state control are expressed formally in a single system as defined in the first chapter of the Constitution of the Republic of Armenia. Compliance and reform of constitutional principles provide the synergy and the constitutionality of the process of governance.

  18. The foundational tenets of Johannes Althusius' constitutionalism ...

    African Journals Online (AJOL)

    Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad ... sovereignty, in contrast to undivided (statist) sovereignty and his views on public office provided the framework for constitutionalism and limited government which could arguably improve on that of contemporary statist constitutionalism.

  19. Unconstitutional constitutional amendments in Ethiopia: the practice ...

    African Journals Online (AJOL)

    Haramaya Law Review ... The Constitution of the Federal Democratic Republic of Ethiopia (FDRE) under Article 104 and 105 sets ... that sets procedures to be observed in the process of constitutional amendments: both initiation and approval.

  20. The constitutional court review of judicial decisions

    Directory of Open Access Journals (Sweden)

    Stojanović Dragan M.

    2016-01-01

    Full Text Available In principle, the constitutional precepts envisage that judicial decisions are not subject to extrajudicial control. However, in the course of deciding on constitutional complaints, the Constitutional Court reviews the compliance of individual legal acts and actions of state authorities with the Constitution, including court decisions on cases involving the constitutionally guaranteed rights. Hence, in order to eliminate tension or even contradiction between the constitutional precepts, the constitutional review of judicial decisions should be considered as a special form of judicial control, regardless of the fact that the Constitutional Court is not part of the judicial structure in the strict organizational sense. Thus, unlike the cases where the Court is involved in the normative control of the applicable law, in the process of reviewing judicial decision of lower courts the constitutional judiciary acts in the capacity of a specific judicial authority. According to another possible interpretation of the aforementioned constitutional norms, the direct constitutional protection of the constitutionally guaranteed rights may only be pursued in the process of reviewing individual legal acts and actions of state authorities, but not by pursuing a judicial review of court decisions which the Constitutional Court has no jurisdiction to decide upon. Thus, the dogma of judicial independence would prevail over the dogma of direct protection of fundamental rights. The third interpretation of this relationship maintains that that judicial decisions may be subject to control but, in this specific case, the Constitutional Court may only issue an opinion (a statement rather than a binding decision which would cancel the lower court judgment. Then, it is up to the judicial authorities of the lower instance to adjust their judicial decision, which in the opinion of the Constitutional Court constitutes a violation of the constitutionally guaranteed rights

  1. Comparison of the spaceflight transcriptome of four commonly used Arabidopsis thaliana ecotypes

    Data.gov (United States)

    National Aeronautics and Space Administration — This experiment compared the spaceflight transcriptomes of four commonly used natural variants (ecotypes) of Arabidopsis thaliana using RNAseq. In nature Arabidopsis...

  2. Unanimous Constitutional Consent and the Immigration Problem

    OpenAIRE

    Josten, Stefan D.; Zimmermann, Klaus W.

    2004-01-01

    This paper utilizes the cross-cutting cleavages approach to evaluate the probability of a unanimous constitutional consent and, based on these results, discusses the implications of immigration on an existing constitutional consent. It is shown that previous conclusions of beneficial effects stemming from a multitude of political dimensions for a unanimous constitutional consent crucially depend on the assumption of an extreme mode of intrapersonal compensation of constitutional majority and ...

  3. Constitutional Referendums:A Theoretical Enquiry

    OpenAIRE

    Tierney, Stephen

    2009-01-01

    In recent decades the use of referendums to settle major constitutional questions has increased dramatically. Addressing this phenomenon as a case study in the relationship between democracy and constitutional sovereignty, this article has two aims.The first is to argue that these constitutional referendums are categorically different from ordinary, legislative referendums, and that this has important implications for theories of constitutional sovereignty. Secondly, the article suggests that...

  4. Analysis on constitution of American college republicans

    Direct