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Sample records for campestris global regulator

  1. The cyclic nucleotide monophosphate domain of Xanthomonas campestris global regulator Clp defines a new class of cyclic di-GMP effectors.

    Science.gov (United States)

    Tao, Fei; He, Ya-Wen; Wu, Dong-Hui; Swarup, Sanjay; Zhang, Lian-Hui

    2010-02-01

    The widely conserved second messenger cyclic diguanosine monophosphate (c-di-GMP) plays a key role in quorum-sensing (QS)-dependent production of virulence factors in Xanthomonas campestris pv. campestris. The detection of QS diffusible signal factor (DSF) by the sensor RpfC leads to the activation of response regulator RpfG, which activates virulence gene expression by degrading c-di-GMP. Here, we show that a global regulator in the X. campestris pv. campestris QS regulatory pathway, Clp, is a c-di-GMP effector. c-di-GMP specifically binds to Clp with high affinity and induces allosteric conformational changes that abolish the interaction between Clp and its target gene promoter. Clp is similar to the cyclic AMP (cAMP) binding proteins Crp and Vfr and contains a conserved cyclic nucleotide monophosphate (cNMP) binding domain. Using site-directed mutagenesis, we found that the cNMP binding domain of Clp contains a glutamic acid residue (E99) that is essential for c-di-GMP binding. Substituting the residue with serine (E99S) resulted in decreased sensitivity to changes in the intracellular c-di-GMP level and attenuated bacterial virulence. These data establish the direct role of Clp in the response to fluctuating c-di-GMP levels and depict a novel mechanism by which QS links the second messenger with the X. campestris pv. campestris virulence regulon.

  2. Co-regulation of Xanthomonas campestris virulence by quorum sensing and a novel two-component regulatory system RavS/RavR.

    Science.gov (United States)

    He, Ya-Wen; Boon, Calvin; Zhou, Lian; Zhang, Lian-Hui

    2009-03-01

    Xanthomonas campestris pv. campestris (Xcc) is known to regulate virulence through a quorum-sensing mechanism. Detection of the quorum-sensing signal DSF by sensor RpfC leads to activation of the response regulator RpfG, which influences virulence by degrading cyclic-di-GMP and by subsequent increasing expression of the global regulator Clp. In this study, we show that mutation of a response regulator RavR containing the GGDEF-EAL domains decreases Xcc virulence factor production. The functionality of RavR is dependent on its EAL domain-associated cyclic-di-GMP phosphodiesterase activity. Deletion of a multidomain sensor gene ravS, which shares the same operon with ravR, results in similar phenotype changes as the ravR mutant. In addition, the sensor mutant phenotypes can be rescued by in trans expression of the response regulator, supporting the notion that RavS and RavR constitute a two-component regulatory system. Significantly, mutation of either the PAS domain or key residues of RavS implicated in sensing low-oxygen tension abrogates the sensor activity in virulence regulation. Moreover, similar to the DSF signalling system, RavS/RavR regulates virulence gene expression through the global regulator Clp. These results outline a co-regulation mechanism that allows Xcc to integrate population density and environmental cues to modulate virulence factor production and adaptation.

  3. Regulation of the synthesis of cyclic glucan in Xanthomonas campestris by a diffusible signal molecule.

    Science.gov (United States)

    Vojnov, A A; Slater, H; Newman, M A; Daniels, M J; Dow, J M

    2001-12-01

    The rpf gene cluster of Xanthomonas campestris pv. campestris is involved in the co-ordinate positive regulation of the production of extracellular enzymes and the extracellular polysaccharide xanthan. Several of the rpf genes are involved in a regulatory system involving the small diffusible molecule DSF (for diffusible signal factor). Synthesis of DSF requires RpfF, and a two-component sensory transduction system involving RpfC has been implicated in the perception of the signal and signal transduction. Here we show that mutations in both rpfF and rpfC lead to reductions in the levels of cyclic glucan. The levels of cyclic glucan synthetase in membrane preparations from rpfF and rpfC mutants were, however, unaltered from the wild-type. Similar alterations in the level of cyclic glucan without changes in cyclic glucan synthetase activity were seen when wild-type bacteria were exposed to osmotic stress. These results extend the range of cellular functions subject to regulation by the rpf genes and DSF system.

  4. Fatty acid DSF binds and allosterically activates histidine kinase RpfC of phytopathogenic bacterium Xanthomonas campestris pv. campestris to regulate quorum-sensing and virulence.

    Directory of Open Access Journals (Sweden)

    Zhen Cai

    2017-04-01

    Full Text Available As well as their importance to nutrition, fatty acids (FA represent a unique group of quorum sensing chemicals that modulate the behavior of bacterial population in virulence. However, the way in which full-length, membrane-bound receptors biochemically detect FA remains unclear. Here, we provide genetic, enzymological and biophysical evidences to demonstrate that in the phytopathogenic bacterium Xanthomonas campestris pv. campestris, a medium-chain FA diffusible signal factor (DSF binds directly to the N-terminal, 22 amino acid-length sensor region of a receptor histidine kinase (HK, RpfC. The binding event remarkably activates RpfC autokinase activity by causing an allosteric change associated with the dimerization and histidine phosphotransfer (DHp and catalytic ATP-binding (CA domains. Six residues were found essential for sensing DSF, especially those located in the region adjoining to the inner membrane of cells. Disrupting direct DSF-RpfC interaction caused deficiency in bacterial virulence and biofilm development. In addition, two amino acids within the juxtamembrane domain of RpfC, Leu172 and Ala178, are involved in the autoinhibition of the RpfC kinase activity. Replacements of them caused constitutive activation of RpfC-mediated signaling regardless of DSF stimulation. Therefore, our results revealed a biochemical mechanism whereby FA activates bacterial HK in an allosteric manner, which will assist in future studies on the specificity of FA-HK recognition during bacterial virulence regulation and cell-cell communication.

  5. Fatty acid DSF binds and allosterically activates histidine kinase RpfC of phytopathogenic bacterium Xanthomonas campestris pv. campestris to regulate quorum-sensing and virulence.

    Science.gov (United States)

    Cai, Zhen; Yuan, Zhi-Hui; Zhang, Huan; Pan, Yue; Wu, Yao; Tian, Xiu-Qi; Wang, Fang-Fang; Wang, Li; Qian, Wei

    2017-04-01

    As well as their importance to nutrition, fatty acids (FA) represent a unique group of quorum sensing chemicals that modulate the behavior of bacterial population in virulence. However, the way in which full-length, membrane-bound receptors biochemically detect FA remains unclear. Here, we provide genetic, enzymological and biophysical evidences to demonstrate that in the phytopathogenic bacterium Xanthomonas campestris pv. campestris, a medium-chain FA diffusible signal factor (DSF) binds directly to the N-terminal, 22 amino acid-length sensor region of a receptor histidine kinase (HK), RpfC. The binding event remarkably activates RpfC autokinase activity by causing an allosteric change associated with the dimerization and histidine phosphotransfer (DHp) and catalytic ATP-binding (CA) domains. Six residues were found essential for sensing DSF, especially those located in the region adjoining to the inner membrane of cells. Disrupting direct DSF-RpfC interaction caused deficiency in bacterial virulence and biofilm development. In addition, two amino acids within the juxtamembrane domain of RpfC, Leu172 and Ala178, are involved in the autoinhibition of the RpfC kinase activity. Replacements of them caused constitutive activation of RpfC-mediated signaling regardless of DSF stimulation. Therefore, our results revealed a biochemical mechanism whereby FA activates bacterial HK in an allosteric manner, which will assist in future studies on the specificity of FA-HK recognition during bacterial virulence regulation and cell-cell communication.

  6. Fatty acid DSF binds and allosterically activates histidine kinase RpfC of phytopathogenic bacterium Xanthomonas campestris pv. campestris to regulate quorum-sensing and virulence

    Science.gov (United States)

    Zhang, Huan; Pan, Yue; Wu, Yao; Tian, Xiu-Qi; Wang, Fang-Fang; Wang, Li

    2017-01-01

    As well as their importance to nutrition, fatty acids (FA) represent a unique group of quorum sensing chemicals that modulate the behavior of bacterial population in virulence. However, the way in which full-length, membrane-bound receptors biochemically detect FA remains unclear. Here, we provide genetic, enzymological and biophysical evidences to demonstrate that in the phytopathogenic bacterium Xanthomonas campestris pv. campestris, a medium-chain FA diffusible signal factor (DSF) binds directly to the N-terminal, 22 amino acid-length sensor region of a receptor histidine kinase (HK), RpfC. The binding event remarkably activates RpfC autokinase activity by causing an allosteric change associated with the dimerization and histidine phosphotransfer (DHp) and catalytic ATP-binding (CA) domains. Six residues were found essential for sensing DSF, especially those located in the region adjoining to the inner membrane of cells. Disrupting direct DSF-RpfC interaction caused deficiency in bacterial virulence and biofilm development. In addition, two amino acids within the juxtamembrane domain of RpfC, Leu172 and Ala178, are involved in the autoinhibition of the RpfC kinase activity. Replacements of them caused constitutive activation of RpfC-mediated signaling regardless of DSF stimulation. Therefore, our results revealed a biochemical mechanism whereby FA activates bacterial HK in an allosteric manner, which will assist in future studies on the specificity of FA-HK recognition during bacterial virulence regulation and cell-cell communication. PMID:28369120

  7. hpaR, a putative marR family transcriptional regulator, is positively controlled by HrpG and HrpX and involved in the pathogenesis, hypersensitive response, and extracellular protease production of Xanthomonas campestris pathovar campestris.

    Science.gov (United States)

    Wei, Ke; Tang, Dong-Jie; He, Yong-Qiang; Feng, Jia-Xun; Jiang, Bo-Le; Lu, Guang-Tao; Chen, Baoshan; Tang, Ji-Liang

    2007-03-01

    The MarR family of transcriptional regulators of bacteria are involved in the regulation of many cellular processes, including pathogenesis. In this work, we have demonstrated genetically that hpaR (hpa, hrp associated), which encodes a putative MarR family regulator, is involved in the hypersensitive response (HR), pathogenicity, and extracellular protease production of the phytopathogenic bacterium Xanthomonas campestris pathovar campestris. A mutation in hpaR resulted in complete loss of virulence in the host plant cabbage, a delayed and weakened HR in the nonhost plant pepper ECW-10R, and an increase in extracellular protease production. Detection of the beta-glucuronidase activity of a plasmid-driven hpaR promoter-gusA reporter revealed that the expression of hpaR is positively controlled by HrpG and HrpX and is suppressed in rich medium while being strongly induced in minimal and hrp-inducing media and inside the host. These findings indicate that hpaR belongs to the hrpG and hrpX regulon and that HrpX regulates the extracellular protease production via hpaR in X. campestris pv. campestris.

  8. Regulation of cell wall-bound invertase in pepper leaves by Xanthomonas campestris pv. vesicatoria type three effectors.

    Directory of Open Access Journals (Sweden)

    Sophia Sonnewald

    Full Text Available Xanthomonas campestris pv. vesicatoria (Xcv possess a type 3 secretion system (T3SS to deliver effector proteins into its Solanaceous host plants. These proteins are involved in suppression of plant defense and in reprogramming of plant metabolism to favour bacterial propagation. There is increasing evidence that hexoses contribute to defense responses. They act as substrates for metabolic processes and as metabolic semaphores to regulate gene expression. Especially an increase in the apoplastic hexose-to-sucrose ratio has been suggested to strengthen plant defense. This shift is brought about by the activity of cell wall-bound invertase (cw-Inv. We examined the possibility that Xcv may employ type 3 effector (T3E proteins to suppress cw-Inv activity during infection. Indeed, pepper leaves infected with a T3SS-deficient Xcv strain showed a higher level of cw-Inv mRNA and enzyme activity relative to Xcv wild type infected leaves. Higher cw-Inv activity was paralleled by an increase in hexoses and mRNA abundance for the pathogenesis-related gene PRQ. These results suggest that Xcv suppresses cw-Inv activity in a T3SS-dependent manner, most likely to prevent sugar-mediated defense signals. To identify Xcv T3Es that regulate cw-Inv activity, a screen was performed with eighteen Xcv strains, each deficient in an individual T3E. Seven Xcv T3E deletion strains caused a significant change in cw-Inv activity compared to Xcv wild type. Among them, Xcv lacking the xopB gene (Xcv ΔxopB caused the most prominent increase in cw-Inv activity. Deletion of xopB increased the mRNA abundance of PRQ in Xcv ΔxopB-infected pepper leaves, but not of Pti5 and Acre31, two PAMP-triggered immunity markers. Inducible expression of XopB in transgenic tobacco inhibited Xcv-mediated induction of cw-Inv activity observed in wild type plants and resulted in severe developmental phenotypes. Together, these data suggest that XopB interferes with cw-Inv activity in planta to

  9. Regulation of cell wall-bound invertase in pepper leaves by Xanthomonas campestris pv. vesicatoria type three effectors.

    Science.gov (United States)

    Sonnewald, Sophia; Priller, Johannes P R; Schuster, Julia; Glickmann, Eric; Hajirezaei, Mohammed-Reza; Siebig, Stefan; Mudgett, Mary Beth; Sonnewald, Uwe

    2012-01-01

    Xanthomonas campestris pv. vesicatoria (Xcv) possess a type 3 secretion system (T3SS) to deliver effector proteins into its Solanaceous host plants. These proteins are involved in suppression of plant defense and in reprogramming of plant metabolism to favour bacterial propagation. There is increasing evidence that hexoses contribute to defense responses. They act as substrates for metabolic processes and as metabolic semaphores to regulate gene expression. Especially an increase in the apoplastic hexose-to-sucrose ratio has been suggested to strengthen plant defense. This shift is brought about by the activity of cell wall-bound invertase (cw-Inv). We examined the possibility that Xcv may employ type 3 effector (T3E) proteins to suppress cw-Inv activity during infection. Indeed, pepper leaves infected with a T3SS-deficient Xcv strain showed a higher level of cw-Inv mRNA and enzyme activity relative to Xcv wild type infected leaves. Higher cw-Inv activity was paralleled by an increase in hexoses and mRNA abundance for the pathogenesis-related gene PRQ. These results suggest that Xcv suppresses cw-Inv activity in a T3SS-dependent manner, most likely to prevent sugar-mediated defense signals. To identify Xcv T3Es that regulate cw-Inv activity, a screen was performed with eighteen Xcv strains, each deficient in an individual T3E. Seven Xcv T3E deletion strains caused a significant change in cw-Inv activity compared to Xcv wild type. Among them, Xcv lacking the xopB gene (Xcv ΔxopB) caused the most prominent increase in cw-Inv activity. Deletion of xopB increased the mRNA abundance of PRQ in Xcv ΔxopB-infected pepper leaves, but not of Pti5 and Acre31, two PAMP-triggered immunity markers. Inducible expression of XopB in transgenic tobacco inhibited Xcv-mediated induction of cw-Inv activity observed in wild type plants and resulted in severe developmental phenotypes. Together, these data suggest that XopB interferes with cw-Inv activity in planta to suppress sugar

  10. Retraction statement: Dynamic complex formation between HD-GYP, GGDEF and PilZ domain proteins regulates motility in Xanthomonas campestris.

    Science.gov (United States)

    2017-05-01

    The following article from Molecular Microbiology (2012) 86(3), 557-567, 'Dynamic complex formation between HD-GYP, GGDEF and PilZ domain proteins regulates motility in Xanthomonas campestris' by Robert P. Ryan, Yvonne McCarthy, Patrick A. Kiely, Rosemary O'Connor, Chuck S. Farah, Judith P. Armitage and J. Maxwell Dow published online in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, John D Helmann, and John Wiley & Sons Ltd. Since publication of the above article, it has been brought to our attention that there are several image duplications across Figures 3, 5 and 6 including duplication with another article in PNAS: 'Cell-cell signal-dependent dynamic interactions between HD-GYP and GGDEF domain proteins mediate virulence in Xanthomonas campestris', by Robert P. Ryan, Yvonne McCarthy, Maxuel Andrade, Chuck S. Farah, Judith P. Armitage, and J. Maxwell Dow; PNAS (2010) 107(13), 5989-5994. The authors apologise for the errors that arose due to poor labelling of the electronic images used in the construction of the figures and for not spotting the duplication during review, and, with agreement of all parties, the decision has been made to retract this article. We apologise for any inconvenience the publication of this work may have caused our readers. Ryan, R.P., McCarthy, Y., Andrade, M., Farah, C.S., Armitage, J.P., and Dow, J.M. (2010) Cell-cell signal-dependent dynamic interactions between HD-GYP and GGDEF domain proteins mediate virulence in Xanthomonas campestris. PNAS 107: 5989-5994. DOI: 10.1073/pnas.0912839107. Ryan, R.P., McCarthy, Y., Kiely, P.A., O'connor, R., Farah, C.S., Armitage, J.P., and Dow, J.M. (2012) Dynamic complex formation between HD-GYP, GGDEF and PilZ domain proteins regulates motility in Xanthomonas campestris. Mol Microbiol 86: 557-567. DOI: 10.1111/mmi.12000. © 2017 John Wiley & Sons Ltd.

  11. USING Xanthomonas Campestris

    African Journals Online (AJOL)

    eobe

    study by Huanget al. [18]. The peels were washed with clean water to remove any adhering dirt after which they were blended to obtain a slurry which was autoclaved ..... Xanthan employing Xanthomonas campestris using. Sugarcane Molasses”,. American Journal of. Environmental Engineering, Vol. 2, Number 2, 2012, pp.

  12. Xanthomonas campestris pv. campestris race 1 is the main causal ...

    African Journals Online (AJOL)

    Severe outbreaks of bacterial black rot caused by Xanthomonas campestris pv. campestris (Xcc) were observed in Brassica production fields of Southern Mozambique. The causal agent of the disease in the Mahotas and Chòkwé districts was identified and characterised. In total, 83 Xanthomonas-like strains were isolated ...

  13. Identification of Xanthomonas campestris pv. campestris galactose utilization genes from transcriptome data.

    Science.gov (United States)

    Serrania, Javier; Vorhölter, Frank-Jörg; Niehaus, Karsten; Pühler, Alfred; Becker, Anke

    2008-06-30

    A 70 mer oligonucleotide microarray was constructed to analyze genome-wide expression profiles of Xanthomonas campestris pv. campestris B100, a plant-pathogenic bacterium that is industrially employed to produce the exopolysaccharide xanthan gum which has many applications as a stabilizing, thickening, gelling, and emulsifying agent in food, pharmaceutical, and cosmetic industries. As an application example, global changes of gene expression were monitored during growth of X. campestris pv. campestris B100 on two different carbon sources. Exponential growing bacterial cultures were incubated either for 1h or permanently in minimal medium supplemented with 1% galactose in comparison to growth in minimal medium supplemented with 1% glucose. Six genes were identified that were significantly increased in gene expression under both growth conditions. These genes were located in three distinguished chromosomal regions in operon-like gene clusters. Genes from these clusters encode secreted glycosidases, which were predicted to be specific for galactose-containing carbohydrates, as well as transport proteins probably located in the outer and inner cell membrane. Finally genes from one cluster code for cytoplasmic enzymes of a metabolic pathway specific for the breakdown of galactose to intermediates of glycolysis.

  14. DNA polymorphism analysis of Xanthomonas campestris pv ...

    African Journals Online (AJOL)

    strand conformation polymorphism (SSCP) techniques using M13 and 16S rRNA primers, respectively, for genotyping of the phytopathogenic bacterium Xanthomonas campestris pv. campestris was studied. RAPD provided a simple, rapid, and ...

  15. Antagonism of Bacillus spp. against Xanthomonas campestris pv. campestris

    Directory of Open Access Journals (Sweden)

    Leila Monteiro

    2005-01-01

    Full Text Available The antagonism of eight Bacillus isolates was investigated against nine strains of Xanthomonas campestris pv. campestris (causal agent of crucifers black rot to assess the role of lipopeptides in this process. Antimicrobial and hemolytic (surfactant activity tests were performed in vitro using agar diffusion methods. Antibiosis and hemolysis were positive for four Bacillus isolates against all X. campestris pv. campestris strains. The correlation observed between antimicrobial and hemolytic activities indicated that lipopeptides were involved in the antibiosis mechanism of the studied antagonists. Fermentation studies were carried out with the isolates that showed highest antimicrobial and hemolytic activities, to follow up growth and production of bioactive and surfactant compounds. Production of bioactive and surfactant compounds was observed during the late growth phase of the Bacillus isolates.Investigação sobre o antagonismo de oito isolados de Bacillus: B. subtilis R14, B. megaterium pv. cerealis RAB7, B. megaterium pv. cerealis C211, B. megaterium C116, Bacillus sp. RAB9, B. cereus C240, Bacillus sp. C11 e B. cereus C210, contra nove linhagens de X. campestris pv. campestris (bactéria responsável pela podridão negra das crucíferas foi realizada para se verificar a participação de lipopeptídeos neste mecanismo. Testes de atividades antimicrobiana e hemolítica (surfactante foram realizados, utilizando-se o método de difusão em ágar. Antibiose e hemólise foram positivas para quatro isolados de Bacillus: R14, RAB7, C116 e C210. A correlação observada entre as atividades antimicrobiana e a hemolítica indica que lipopeptídeos estão envolvidos no mecanismo de antibiose dos isolados investigados. As fermentações foram realizadas com os isolados que demonstraram melhores resultados nos testes de atividades antimicrobiana e hemolítica: R14, RAB7 e C116, para acompanhar o crescimento e a produção de compostos bioativos e

  16. Xanthan gum production by Xanthomonas campestris pv ...

    African Journals Online (AJOL)

    Cassava starch is a main renewable bio-resource with low price and mass production in Guangxi, China. It was used as carbon source in growing Xanthomonas campestris pv. campestris 8004 (Xcc 8004) for xanthan gum production in this study. The xanthan gum yield of gelatinized cassava starch was higher than that of ...

  17. Transmission of Xanthomonas campestris pv. campestris in seed production crops of cauliflower

    NARCIS (Netherlands)

    Kastelein, P.; Krijger, M.C.; Zouwen, van der P.S.; Steen, van der J.J.M.; Stevens, L.H.; Wolf, van der J.M.; Fernandes Vieira, J.; Amaral Villela, F.

    2014-01-01

    n 2011, two polytunnel greenhouse experiments were conducted on seed production farms, one under conventional conditions in the South-West (Rilland) and the other under organic conditions in the East (Voorst) of the Netherlands, to study transmission routes of Xanthomonas campestris pv. campestris

  18. Identification and Origin of Xanthomonas campestris pv. campestris Races and Related Pathovars.

    Science.gov (United States)

    Vicente, J G; Conway, J; Roberts, S J; Taylor, J D

    2001-05-01

    ABSTRACT One hundred sixty-four isolates of Xanthomonas campestris pv. campestris and other X. campestris pathovars known to infect cruciferous hosts (X. campestris pvs. aberrans, raphani, armoraciae, and incanae) were inoculated onto a differential series of Brassica spp. to determine both pathogenicity to brassicas and race. Of these, 144 isolates were identified as X. campestris pv. campestris and grouped into six races, with races 1 (62%) and 4 (32%) being predominant. Other races were rare. The remaining 20 isolates from brassicas and other cruciferous hosts were either nonpathogenic or very weakly pathogenic on the differential series and could not be race-typed. Five of these isolates, from the ornamental crucifers wallflower (Cheiranthus cheiri), stock (Matthiola incana) and candytuft (Iberis sp.), showed clear evidence of pathovar-like specificity to the hosts of origin. A gene-for-gene model based on the interaction of four avirulence genes in X. campestris pv. campestris races and four matching resistance genes in the differential hosts is proposed. Knowledge of the race structure and worldwide distribution of races is fundamental to the search for sources of resistance and for the establishment of successful resistance breeding programs.

  19. Achieving global perfect homeostasis through transporter regulation

    Science.gov (United States)

    Springer, Michael

    2017-01-01

    Nutrient homeostasis—the maintenance of relatively constant internal nutrient concentrations in fluctuating external environments—is essential to the survival of most organisms. Transcriptional regulation of plasma membrane transporters by internal nutrient concentrations is typically assumed to be the main mechanism by which homeostasis is achieved. While this mechanism is homeostatic we show that it does not achieve global perfect homeostasis—a condition where internal nutrient concentrations are completely independent of external nutrient concentrations for all external nutrient concentrations. We show that the criterion for global perfect homeostasis is that transporter levels must be inversely proportional to net nutrient flux into the cell and that downregulation of active transporters (activity-dependent regulation) is a simple and biologically plausible mechanism that meets this criterion. Activity-dependent transporter regulation creates a trade-off between robustness and efficiency, i.e., the system's ability to withstand perturbation in external nutrients and the transporter production rate needed to maintain homeostasis. Additionally, we show that a system that utilizes both activity-dependent transporter downregulation and regulation of transporter synthesis by internal nutrient levels can create a system that mitigates the shortcomings of each of the individual mechanisms. This analysis highlights the utility of activity-dependent regulation in achieving homeostasis and calls for a re-examination of the mechanisms of regulation of other homeostatic systems. PMID:28414718

  20. Flavonoids from Lonchocarpus campestris (Leguminosae); Flavonoides de Lonchocarpus campestris (Leguminosae)

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Andreza Maria L.; Silveira, Edilberto R.; Pessoa, Otilia Deusdenia L., E-mail: opessoa@ufc.b [Universidade Federal do Ceara (DQOI/UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica

    2011-07-01

    A new flavone named 3,4',5,6-tetramethoxy-[2'', 3'':7,8] furanoflavone besides the known flavonoids (2S,3R,4S)-3,4,5,8-tetramethoxy-[2'',3'':6,7]-furanoflavan, 3,6-dimethoxy-2'',2''-dimethylcromene-[2'',3'':7,8]-flavone, 3,5,6-trimethoxy-[2'',3'':7,8]-furanoflavone, 2,4',4,5-tetramethoxy-[2'',3'':6,7]-furanodihydroaurone, (2R,3S,4S)-3,4,5,6-tetramethoxy-[2'',3'':7,8]-furanoflavan and 3',4'-methylenedioxy-5,6-dimethoxy-[2'',3'':7,8]-furanoflavone were isolated from the root barks of Lonchocarpus campestris. The complete {sup 1}H and {sup 13}C NMR assignments of the new furan flavonoid was performed using 1D and 2D pulse sequences, including COSY, HMQC and HMBC experiments. (author)

  1. Arbitrage and Competition in Global Financial Regulation

    DEFF Research Database (Denmark)

    Ringe, Wolf-Georg

    Regulatory arbitrage in financial markets refers to a number of strategies that market participants use to avoid the reach of regulation, in particular by virtue of shifting trading abroad or else relocating activities or operations of financial institutions to other jurisdictions. Where...... their standards solely to attract businesses and thereby impose externalities on the worldwide financial market by undermining financial stability as a global public good. Policymakers worldwide are experimenting with remedies to respond to the phenomenon. I introduce the importance of an effective special...... institutions’ excessive risk-taking. If such risk-taking would be judged by market discipline instead of posing a risk to global financial stability, the main downside of regulatory competition could be restrained. Within the boundaries of such a system, competition could then operate and contribute...

  2. Chokepoints global private regulation on the Internet

    CERN Document Server

    Tusikov, Natasha

    2016-01-01

    In January 2012, millions participated in the now-infamous "Internet blackout" against the Stop Online Piracy Act, protesting the power it would have given intellectual property holders over the Internet. However, while SOPA's withdrawal was heralded as a victory for an open Internet, a small group of corporations, tacitly backed by the US and other governments, have implemented much of SOPA via a series of secret, handshake agreements. Drawing on extensive interviews, Natasha Tusikov details the emergence of a global regime in which large Internet firms act as regulators for powerful intellec

  3. and Saccostomus campestris (Cricetomyinae) in relation to ...

    African Journals Online (AJOL)

    forestomach papillae supporting vast colonies of symbiotic bacteria that are not found in S. campestris. ... symbiotic bacteria attached to gastric papillae is to elevate alpha amylase activity and aid starch! glycogen ..... animals (Bauchop 1978) and in C. gambianus are known to ferment glucose (liberating alcohols), hydrolyse ...

  4. Hydrologic Regulation of Global Geochemical Cycles

    Science.gov (United States)

    Maher, K.

    2015-12-01

    Earth's temperature is thought to be regulated by a negative feedback between atmospheric CO2 levels and chemical weathering of silicate rocks. However, direct evidence for the operation of this feedback over million-year timescales is difficult to obtain. For example, weathering fluxes over the last 20 million years of the Cenozoic Era, calculated using marine isotopic proxies (i.e. 87Sr/86Sr, δ7Li, and 187Os/188Os), appear inconsistent with past atmospheric CO2 levels and carbon mass balance. Similarly, observations from modern catchments suggest that chemical weathering fluxes are strongly correlated with erosion rates and only weakly correlated with temperature. As an alternative approach to evaluating the operation of a negative feedback, we use the major surface reservoirs of carbon to determine the imbalance in the geologic carbon cycle and the required silicate weathering flux over the Cenozoic. A miniscule (0.5-1%) increase in silicate weathering is necessary to explain the long-term decline in CO2 levels over the Cenozoic, providing evidence for a strong negative feedback between silicate weathering and climate. Rather than an appreciable increase in the silicate weathering flux, the long-term decrease in CO2levels may be due to an increase in the strength of the silicate weathering feedback. To explain the observed variations in the strength of the weathering feedback during the Cenozoic, we present a model for silicate weathering where hydrologic processes regulate climatic and tectonic forcings due to the presence of a thermodynamic limit to weathering fluxes. Climate regulation by silicate weathering is thus strongest when global topography is elevated, similar to today, and lowest when global topography is more subdued, allowing planetary temperatures to vary depending on the global distribution of topography and mountain belts. These results also motivate several key outstanding challenges in earth surface processes, including the need to

  5. Over-expression of miR158 causes pollen abortion in Brassica campestris ssp. chinensis.

    Science.gov (United States)

    Ma, Zhiming; Jiang, Jianxia; Hu, Ziwei; Lyu, Tianqi; Yang, Yang; Jiang, Jingjing; Cao, Jiashu

    2017-02-01

    We identified and cloned the two precursors of miR158 and its target gene in Brassica campestris ssp. chinensis, which both had high relative expression in the inflorescences. Further study revealed that over-expression of miR158 caused reduced pollen varbility, which was caused by the degradation of pollen contents from the binucleate microspore stage. These results first suggest the role of miR158 in pollen development of Brassica campestris ssp. chinensis. MicroRNAs (miRNAs) play crucial roles in many important growth and development processes both in plants and animals by regulating the expression of their target genes via mRNA cleavage or translational repression. In this study, miR158, a Brassicaceae specific miRNA, was functionally characterized with regard to its role in pollen development of non-heading Chinese cabbage (Brassica campestris ssp. chinensis). Two family members of miR158 in B. campestris, namely bra-miR158a1 and bra-miR158a2, and their target gene bra027656, which encodes a pentatricopeptide repeat (PPR) containing protein, were identified. Then, qRT-PCR analysis and GUS-reporter system revealed that both bra-miR158 and its target gene had relatively high expression levels in the inflorescences. Further study revealed that over-expression of miR158 caused reduced pollen varbility and pollen germination ratio, and the degradation of pollen contents from the binucleate microspore stage was also found in those deformed pollen grains, which led to pollen shrinking and collapse in later pollen development stage. These results first shed light on the importance of miR158 in pollen development of Brassica campestris ssp. chinensis.

  6. Occurrence of Xanthomonas campestris pv. campestris (Pammel, 1895 Dowson 1939, on Brassicas in Montenegro

    Directory of Open Access Journals (Sweden)

    Dragana Radunović

    2012-01-01

    Full Text Available Brassicas form the most important group of vegetable crops in Montenegro. The cabbage(Brassica oleracea var. capitata is most commonly grown, although other brassicas,particularly kale, Brussels sprout, cauliflower and broccoli, have been increasingly producedsince recently. One of the specialties of vegetable production in Montenegro is growing ofcollard (Brassica oleracea var. acephala, which is the simplest variety of the Brassica oleraceaspecies and in the nearest relation with their wild ancestor – the sylvestris variety.Diseases are the main restrictive factors for successful production of these vegetables.Susceptibility of the cultivars and inadequate control often result in more or less damagedcrops in some plots.Causal agents of brassica diseases, especially bacterial, have not been investigated inMontenegro until 2009. Since the symptoms observed in 2009 were „V” shaped leaf edgenecrosis and black rot of vascular tissue, it was assumed that they were caused by plantpathogenic bacterium Xanthomonas campestris pv. campestris.Samples of the infected plants were collected from different localities in Montenegro.Isolation and identification of the bacterium were performed using laboratory methodsaccording to Schaad (1980, Lelliott and Stead (1987 and Arsenijević (1997. Examinationof chosen bacterial isolates was conducted using both, classical bacteriological methods(examination of their pathogenic, morphological, cultivation and biochemical and physiologicalcharacteristics, and ELISA test.The obtained results confirmed the presence of X.campestris pv. campestris (Pammel,1895 Dowson 1939, on cabbage, kale, broccoli and collard in Montenegro. This is the firstexperimental evidence that collard is the host of X. campestris pv. campestris in Montenegro.

  7. 75 FR 75904 - Global Terrorism Sanctions Regulations; Terrorism Sanctions Regulations; Foreign Terrorist...

    Science.gov (United States)

    2010-12-07

    ... Office of Foreign Assets Control 31 CFR Parts 594, 595, and 597 Global Terrorism Sanctions Regulations; Terrorism Sanctions Regulations; Foreign Terrorist Organizations Sanctions Regulations AGENCY: Office of... (``OFAC'') of the U.S. Department of the Treasury is amending the Global Terrorism Sanctions Regulations...

  8. Dissecting specific and global transcriptional regulation of bacterial gene expression

    NARCIS (Netherlands)

    Gerosa, Luca; Kochanowski, Karl; Heinemann, Matthias; Sauer, Uwe

    Gene expression is regulated by specific transcriptional circuits but also by the global expression machinery as a function of growth. Simultaneous specific and global regulation thus constitutes an additional-but often neglected-layer of complexity in gene expression. Here, we develop an

  9. Natural Genetic Variation of Xanthomonas campestris pv. campestris Pathogenicity on Arabidopsis Revealed by Association and Reverse Genetics

    Science.gov (United States)

    Guy, Endrick; Genissel, Anne; Hajri, Ahmed; Chabannes, Matthieu; David, Perrine; Carrere, Sébastien; Lautier, Martine; Roux, Brice; Boureau, Tristan; Arlat, Matthieu; Poussier, Stéphane; Noël, Laurent D.

    2013-01-01

    ABSTRACT The pathogenic bacterium Xanthomonas campestris pv. campestris, the causal agent of black rot of Brassicaceae, manipulates the physiology and the innate immunity of its hosts. Association genetic and reverse-genetic analyses of a world panel of 45 X. campestris pv. campestris strains were used to gain understanding of the genetic basis of the bacterium’s pathogenicity to Arabidopsis thaliana. We found that the compositions of the minimal predicted type III secretome varied extensively, with 18 to 28 proteins per strain. There were clear differences in aggressiveness of those X. campestris pv. campestris strains on two Arabidopsis natural accessions. We identified 3 effector genes (xopAC, xopJ5, and xopAL2) and 67 amplified fragment length polymorphism (AFLP) markers that were associated with variations in disease symptoms. The nature and distribution of the AFLP markers remain to be determined, but we observed a low linkage disequilibrium level between predicted effectors and other significant markers, suggesting that additional genetic factors make a meaningful contribution to pathogenicity. Mutagenesis of type III effectors in X. campestris pv. campestris confirmed that xopAC functions as both a virulence and an avirulence gene in Arabidopsis and that xopAM functions as a second avirulence gene on plants of the Col-0 ecotype. However, we did not detect the effect of any other effector in the X. campestris pv. campestris 8004 strain, likely due to other genetic background effects. These results highlight the complex genetic basis of pathogenicity at the pathovar level and encourage us to challenge the agronomical relevance of some virulence determinants identified solely in model strains. PMID:23736288

  10. Especificidade de hospedeiro nas interações Xanthomonas campestris pv. campestris - brássicas Host specificity in interaction Xanthomonas campestris pv. campestris - brassicas

    Directory of Open Access Journals (Sweden)

    Dulândula Silva Miguel-Wruck

    2010-06-01

    Full Text Available Face às escassas informações acerca da variabilidade patogênica de isolados brasileiros de Xanthomonas campestris pv. campestris, realizou-se um estudo para avaliar a especificidade patogênica de trinta e três isolados do patógeno, provenientes de várias regiões do Brasil e do exterior, a oito espécies de brássicas, através de inoculação por meio de injeção da suspensão bacteriana nas folhas. Desse total, 12 isolados foram obtidos de couve-comum (Brassica oleracea var. acephala, nove de repolho (B. oleracea var. capitata, cinco de couve-flor (B. oleracea var. botrytis, dois de canola (B. napus, um de brócolos (B. oleracea var. italica, um de couve-chinesa (B. chinensis, um de couve-rábano (B. oleracea var. gongylodes e dois de rabanete (Raphanus sativus. A avaliação da patogenicidade dos isolados da bactéria, frente aos hospedeiros em estudo, demonstrou que 14 deles não apresentaram especificidade, originando sintomas em todas as diferentes plantas inoculadas. Os 19 isolados restantes, entretanto, apresentaram relativo grau de especificidade, não causando doença em uma ou mais das plantas inoculadas.Considering the lack of information in literature about the pathogenic variability of Brazilian isolates of Xanthomonas campestris pv. campestris, a study was carried out to determine the pathogenic specificity of 33 isolates of this bacterium originated from several regions of Brazil and overseas to eight different Brassica species, through inoculation by means of injection of the bacterial suspension in leaves. From these isolates, 12 were obtained from collard greens (Brassica oleracea var. acephala, nine from cabbage (B. oleracea var. capitata, five from cauliflower (B. oleracea var. botrytis, two from canola (B. napus, one from broccoli (B. oleracea var. italica, one from Chinese cabbage (B. chinensis, one from kohlrabi (B. oleracea var. gongylodes and two from radish (Raphanus sativus. The pathogenicity of the bacterium

  11. Global approaches to regulating electronic cigarettes

    OpenAIRE

    Kennedy, Ryan David; Awopegba, Ayodeji; De Le?n, Elaine; Cohen, Joanna E.

    2016-01-01

    Objectives Classify and describe the policy approaches used by countries to regulate e-cigarettes. Methods National policies regulating e-cigarettes were identified by (1) conducting web searches on Ministry of Health websites, and (2) broad web searches. The mechanisms used to regulate e-cigarettes were classified as new/amended laws, or existing laws. The policy domains identified include restrictions or prohibitions on product: sale, manufacturing, importation, distribution, use, product d...

  12. MarR-Family Transcription Factor HpaR Controls Expression of the vgrR-vgrS Operon of Xanthomonas campestris pv. campestris.

    Science.gov (United States)

    Pan, Yue; Liang, Fang; Li, Ru-Jiao; Qian, Wei

    2018-01-03

    MarR (multiple antibiotic resistance regulator)-family transcription factors (TFs), which regulate the expression of virulence factors and other physiological pathways in pathogenic bacteria, are regarded as ideal molecular targets for the development of novel antimicrobial strategies. In the plant bacterial pathogen Xanthomonas campestris pv. campestris, HpaR, a typical MarR-family TF, is associated with bacterial virulence, but its mechanism of virulence regulation remains unclear. Here, we dissected the HpaR regulon using high-throughput RNA sequencing and chromatin immunoprecipitation sequencing. HpaR directly or indirectly controls the expression of approximately 448 genes; it acts both as a transcriptional activator and a repressor to control the expression of downstream genes by directly binding to their promoter regions. The consensus HpaR-binding DNA motifs contain imperfect palindromic sequences similar to [G/T]CAACAATT[C/T]TTG. In-depth analysis revealed that HpaR positively modulates transcription level of the vgrR-vgrS operon that encodes an important two-component signal transduction system to sense iron depletion and regulate bacterial virulence. Epistasis analysis demonstrated that vgrR-vgrS is a core downstream component of HpaR regulation, as overexpression of vgrR restored the phenotypic deficiencies caused by a hpaR mutation. This dissection of the HpaR regulon should facilitate future studies focused on the activating mechanism of HpaR during bacterial infection.

  13. Genetic Construction of Lactose-Utilizing Xanthomonas campestris

    OpenAIRE

    Walsh, Patricia M.; Michael J Haas; Somkuti, George A.

    1984-01-01

    Xanthomonas campestris, the producer of xanthan gum, possesses a β-galactosidase of very low specific activity. Plasmid pGC9114 (RP1::Tn951), generated by the transposition of the lactose transposon Tn951 to RP1, was conjugally transferred into XN1, a nalidixic acid-resistant derivative of X. campestris NRRL B-1459S-4L. Transfer occurred on membrane filters and in broth. The β-galactosidase gene of Tn951 was expressed in X. campestris. The specific activity of β-galactosidase in transconjugan...

  14. Genetic Diversity and Pathogenic Variation of Common Blight Bacteria (Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans) Suggests Pathogen Coevolution with the Common Bean.

    Science.gov (United States)

    Mkandawire, Alexander B C; Mabagala, Robert B; Guzmán, Pablo; Gepts, Paul; Gilbertson, Robert L

    2004-06-01

    ABSTRACT Common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans, is one of the most important diseases of common bean (Phaseolus vulgaris) in East Africa and other bean-growing regions. Xanthomonad-like bacteria associated with CBB in Malawi and Tanzania, East Africa, and in Wisconsin, U.S., were characterized based on brown pigment production, pathogenicity on common bean, detection with an X. campestris pv. phaseoli- or X. campestris pv. phaseoli var. fuscans-specific PCR primer pair, and repetitive element polymerase chain reaction (rep-PCR) and restriction fragment length polymorphism (RFLP) analyses. The common bean gene pool (Andean or Middle American) from which each strain was isolated also was determined. In Malawi, X. campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans were isolated predominantly from Andean or Middle American beans, respectively. In Tanzania, X. campestris pv. phaseoli var. fuscans was most commonly isolated, irrespective of gene pool; whereas, in Wisconsin, only X. campestris pv. phaseoli was isolated from Andean red kidney beans. Three rep-PCR fingerprints were obtained for X. campestris pv. phaseoli strains; two were unique to East African strains, whereas the other was associated with strains collected from all other (mostly New World) locations. RFLP analyses with repetitive DNA probes revealed the same genetic diversity among X. campestris pv. phaseoli strains as did rep-PCR. These probes hybridized with only one or two fragments in the East African strains, but with multiple fragments in the other X. campestris pv. phaseoli strains. East African X. campestris pv. phaseoli strains were highly pathogenic on Andean beans, but were significantly less pathogenic on Middle American beans. In contrast, X. campestris pv. phaseoli strains from New World locations were highly pathogenic on beans of both gene pools. Together, these results indicate the

  15. USA IN THE EMERGING SYSTEM OF GLOBAL FINANCIAL REGULATION

    Directory of Open Access Journals (Sweden)

    V. K. Kulakova

    2016-01-01

    Full Text Available In the globalizing world of fi nancial and economic interdependence, a polycentric, multi-level, and hierarchical system of global financial regulation is emerging. The article highlights two vectors of recent development in international fi nancial regulation: the rise of cooperation through the mechanisms of the Group of Twenty (G-20 on the one hand, and the efforts to maintain the US leading role in global fi nance, on the other hand. In the circumstances of the global fi nancial crisis of 2008, the G-20 countries initiated an international reform of fi nancial regulation. According to G-20 decisions, international standardsetting organizations developed transnational regulatory regimes in the fi elds of banking, derivatives and bankruptcy resolution, and the states now implement these regimes in their jurisdictions. The so-called “soft law system”, which is not legally binding, allows the states to sustain national sovereignty in their fi nancial policy. The United States play a leading role in the international fi nancial reform, as well as in the shaping of the global fi nancial regulation system. The American regulators push for extraterritorial application of the US norms and take other unilateral actions on the international arena. The article also touches upon legitimacy problems of the emerging system of global fi nancial regulation. The most important constrains are the excessive infl uence of the fi nancial industry (“regulatory capture”, the weakness of civil society participation, and also the fact that for the rest of the world the American norms lack legitimacy, as they are adopted by regulators assigned by offi cials elected by population of a foreign territory.

  16. Global Transient Stability and Voltage Regulation for Multimachine Power Systems

    DEFF Research Database (Denmark)

    Gordon, Mark; Hill, David J.

    2008-01-01

    This paper addresses simultaneously the major fundamental and difficult issues of nonlinearity, uncertainty, dimensionality and globality to derive performance enhancing power system stability control. The main focus is on simultaneous enhancement of transient stability and voltage regulation...... Linearization (DFL) technique together with the robust control theory has been further developed and applied to design nonlinear excitation compensators which selectively eliminate system nonlinearities and deal with plant uncertainties and interconnections between generators. Then the so called global control...... law is implemented to coordinate transient stabilizer and voltage regulator for each machine. Digital simulation studies show that global control scheme achieves unified transient stability and voltage regulation in the presence of parametric uncertainties and significant sudden changes in the network...

  17. [Overview of global clinical data management regulations and standards].

    Science.gov (United States)

    Liu, Daniel

    2015-11-01

    Quality and integrity of clinical trials and associated data management is a basis on the scientific and rightly assessments of drug safety and efficacy. While both normalization and standardization of clinical trial procedures assure quality of clinical trials and the relevant data processes, they will drive and improve the efficiency and reliability of real-world deliverables in clinical trials in turn. Currently, the comprehensive standards and practices of clinical trials and associated data management are globally established better, and US and EMA have enacted and implemented adequate guidances and regulations well. China is in the initial stage of development of relevant regulations regarding clinical trials and associated data management. This review will focus on the above-mentioned global regulations and standards of clinical data management in the views of good clinical data management standpoints, making references to improve the Chinese regulative system of clinical data management.

  18. Quantifying the Climate Regulation Values of Ecosystems Globally

    Science.gov (United States)

    Anderson-Teixeira, K. J.; DeLucia, E. H.; Snyder, P. K.; LeBauer, D.; Long, S.

    2014-12-01

    Terrestrial ecosystems play an important role in the climate system, regulating climate through both biogeochemical (greenhouse-gas regulation) and biophysical (regulation of water and energy) mechanisms. However, initiatives aimed at climate protection through land management account only for biogeochemical mechanisms. By ignoring biophysical processes, these initiatives risk promoting suboptimal solutions. Our recently proposed metric for the climate regulation value (CRV) of ecosystems provides one potential approach to quantifying how biogeochemical and biophysical effects combine to determine the climate services of terrestrial ecosystems. In order to provide broadly accessible estimates of CRV for ecosystems worldwide, we have created an online ecosystem climate regulation services calculator with global coverage. The CRV calculator incorporates global maps of climatically significant ecosystem properties (for example, biomass, soil carbon, and evapotranspiration) to provide location-specific CRV estimates. We use this calculator to derive values for forests globally, revealing that CRV commonly differs meaningfully from values derived based purely on carbon storage. In the face of increasing land-use pressures and the increasingly urgent need for climate change mitigation, the CRV calculator has the potential to facilitate improved quantification of ecosystem climate regulation services by scientists, conservationists, policy makers, and the private sector.

  19. Functional characterization and transcriptional analysis of galE gene encoding a UDP-galactose 4-epimerase in Xanthomonas campestris pv. campestris.

    Science.gov (United States)

    Li, Chien-Te; Liao, Chao-Tsai; Du, Shin-Chiao; Hsiao, Yu-Ping; Lo, Hsueh-Hsia; Hsiao, Yi-Min

    2014-01-01

    The Gram-negative plant pathogen Xanthomonas campestris pv. campestris (Xcc) is the causative agent of black rot in crucifers, a disease that causes tremendous agricultural loss. In this study, the Xcc galE gene was characterized. Sequence and mutational analysis demonstrated that the Xcc galE encodes a UDP-galactose 4-epimerase (EC 5.1.3.2), which catalyzes the interconversion of UDP-galactose and UDP-glucose. Alanine substitution of the putative catalytic residues (Ser124, Tyr147, and Lys151) of GalE caused loss of epimerase activity. Further study showed that the Xcc galE mutant had reduced biofilm formation ability. Furthermore, reporter assays revealed that galE transcription exhibits a distinct expression profile under different culture conditions, is subject to catabolite repression, and is positively regulated by Clp and RpfF. In addition, the galE transcription initiation site was mapped. This is the first time that UDP-galactose 4-epimerase has been characterized in the crucifer pathogen Xcc. Copyright © 2013 Elsevier GmbH. All rights reserved.

  20. Fair Trade: Social Regulation in Global Food Markets

    Science.gov (United States)

    Raynolds, Laura T.

    2012-01-01

    This article analyzes the theoretical and empirical parameters of social regulation in contemporary global food markets, focusing on the rapidly expanding Fair Trade initiative. Fair Trade seeks to transform North/South relations by fostering ethical consumption, producer empowerment, and certified commodity sales. This initiative joins an array…

  1. Establishment of an inducing medium for type III effector secretion in Xanthomonas campestris pv. campestris

    Directory of Open Access Journals (Sweden)

    Guo-Feng Jiang

    2013-09-01

    Full Text Available It is well known that the type III secretion system (T3SS and type III (T3 effectors are essential for the pathogenicity of most bacterial phytopathogens and that the expression of T3SS and T3 effectors is suppressed in rich media but induced in minimal media and plants. To facilitate in-depth studies on T3SS and T3 effectors, it is crucial to establish a medium for T3 effector expression and secretion. Xanthomonas campestris pv. campestris (Xcc is a model bacterium for studying plant-pathogen interactions. To date no medium for Xcc T3 effector secretion has been defined. Here, we compared four minimal media (MME, MMX, XVM2, and XOM2 which are reported for T3 expression induction in Xanthomonas spp. and found that MME is most efficient for expression and secretion of Xcc T3 effectors. By optimization of carbon and nitrogen sources and pH value based on MME, we established XCM1 medium, which is about 3 times stronger than MME for Xcc T3 effectors secretion. We further optimized the concentration of phosphate, calcium, and magnesium in XCM1 and found that XCM1 with a lower concentration of magnesium (renamed as XCM2 is about 10 times as efficient as XCM1 (meanwhile, about 30 times stronger than MME. Thus, we established an inducing medium XCM2 which is preferred for T3 effector secretion in Xcc.

  2. Chromosome map of Xanthomonas campestris pv. campestris 17 with locations of genes involved in xanthan gum synthesis and yellow pigmentation.

    Science.gov (United States)

    Tseng, Y H; Choy, K T; Hung, C H; Lin, N T; Liu, J Y; Lou, C H; Yang, B Y; Wen, F S; Weng, S F; Wu, J R

    1999-01-01

    No plasmid was detected in Xanthomonas campestris pv. campestris 17, a strain of the causative agent of black rot in cruciferous plants isolated in Taiwan. Its chromosome was cut by PacI, PmeI, and SwaI into five, two, and six fragments, respectively, and a size of 4.8 Mb was estimated by summing the fragment lengths in these digests. Based on the data obtained from partial digestion and Southern hybridization using probes common to pairs of the overlapping fragments or prepared from linking fragments, a circular physical map bearing the PacI, PmeI, and SwaI sites was constructed for the X. campestris pv. campestris 17 chromosome. Locations of eight eps loci involved in exopolysaccharide (xanthan gum) synthesis, two rrn operons each possessing an unique I-CeuI site, one pig cluster required for yellow pigmentation, and nine auxotrophic markers were determined, using mutants isolated by mutagenesis with Tn5(pfm)CmKm. This transposon contains a polylinker with sites for several rare-cutting restriction endonucleases located between the chloramphenicol resistance and kanamycin resistance (Kmr) genes, which upon insertion introduced additional sites into the chromosome. The recA and tdh genes, with known sequences, were mapped by tagging with the polylinker-Kmr segment from Tn5(pfm)CmKm. This is the first map for X. campestris and would be useful for genetic studies of this and related Xanthomonas species.

  3. Chromosome Map of Xanthomonas campestris pv. campestris 17 with Locations of Genes Involved in Xanthan Gum Synthesis and Yellow Pigmentation

    Science.gov (United States)

    Tseng, Yi-Hsiung; Choy, Ka-Tim; Hung, Chih-Hsin; Lin, Nien-Tsung; Liu, Jane-Yu; Lou, Chih-Hong; Yang, Bih-Ying; Wen, Fu-Shyan; Weng, Shu-Fen; Wu, Jung-Rung

    1999-01-01

    No plasmid was detected in Xanthomonas campestris pv. campestris 17, a strain of the causative agent of black rot in cruciferous plants isolated in Taiwan. Its chromosome was cut by PacI, PmeI, and SwaI into five, two, and six fragments, respectively, and a size of 4.8 Mb was estimated by summing the fragment lengths in these digests. Based on the data obtained from partial digestion and Southern hybridization using probes common to pairs of the overlapping fragments or prepared from linking fragments, a circular physical map bearing the PacI, PmeI, and SwaI sites was constructed for the X. campestris pv. campestris 17 chromosome. Locations of eight eps loci involved in exopolysaccharide (xanthan gum) synthesis, two rrn operons each possessing an unique I-CeuI site, one pig cluster required for yellow pigmentation, and nine auxotrophic markers were determined, using mutants isolated by mutagenesis with Tn5(pfm)CmKm. This transposon contains a polylinker with sites for several rare-cutting restriction endonucleases located between the chloramphenicol resistance and kanamycin resistance (Kmr) genes, which upon insertion introduced additional sites into the chromosome. The recA and tdh genes, with known sequences, were mapped by tagging with the polylinker-Kmr segment from Tn5(pfm)CmKm. This is the first map for X. campestris and would be useful for genetic studies of this and related Xanthomonas species. PMID:9864320

  4. Global pharmaceutical regulation: the challenge of integration for developing states.

    Science.gov (United States)

    Pezzola, Anthony; Sweet, Cassandra M

    2016-12-20

    This paper has set out to map the state of pharmaceutical regulation in the developing world through the construction of cross-national indices drawing from World Health Organization data. The last two decades have been characterized by deep changes for the pharmaceutical sector, including the complete transformation of intellectual property systems at the behest of the World Trade Organization and the consolidation of global active ingredient suppliers in China and India. Although the rules for ownership of medicine have been set and globally implemented, we know surprisingly little about how the standards for market entrance and regulation of pharmaceutical products have changed at the national level. How standardized are national pharmaceutical market systems? Do we find homogeneity or variation across the developing world? Are their patterns for understanding why some countries have moved closer to one global norm for pharmaceutical regulation and others have developed hybrid models for oversight of this sector? Access to medicine is a core tool in public health. This paper gauges the levels of standards in public and private generics markets for developing countries building on national-level pharmaceutical market surveys for 78 countries to offer three indicators of market oversight: State Regulatory Infrastructure, Monitoring the Private Market and Public Quality Control. Identifying the different variables that affect a state's institutional capacity and current standard level offers new insights to the state of pharmaceuticals in the developing world. It is notable that there are very few (none at the time of this paper) studies that map out the new global terrain for pharmaceutical regulation in the post-TRIPS context. This paper uses item response theory to develop original indicators of pharmaceutical regulation. We find remarkable resistance to the implementation of global pharmaceutical norms for quality standards in developing states and in

  5. Genetic Construction of Lactose-Utilizing Xanthomonas campestris.

    Science.gov (United States)

    Walsh, P M; Haas, M J; Somkuti, G A

    1984-02-01

    Xanthomonas campestris, the producer of xanthan gum, possesses a beta-galactosidase of very low specific activity. Plasmid pGC9114 (RP1::Tn951), generated by the transposition of the lactose transposon Tn951 to RP1, was conjugally transferred into XN1, a nalidixic acid-resistant derivative of X. campestris NRRL B-1459S-4L. Transfer occurred on membrane filters and in broth. The beta-galactosidase gene of Tn951 was expressed in X. campestris. The specific activity of beta-galactosidase in transconjugants was over 200-fold higher than that in XN1, and transconjugants grew as well in lactose-based media as in glucose-based media. The lactose-utilizing transconjugants could potentially be used to produce xanthan gum from cheese whey.

  6. Cadmium-Induced Hydrogen Accumulation Is Involved in Cadmium Tolerance in Brassica campestris by Reestablishment of Reduced Glutathione Homeostasis.

    Science.gov (United States)

    Wu, Qi; Su, Nana; Chen, Qin; Shen, Wenbiao; Shen, Zhenguo; Xia, Yan; Cui, Jin

    2015-01-01

    Hydrogen gas (H2) was recently proposed as a therapeutic antioxidant and signaling molecule in clinical trials. However, the underlying physiological roles of H2 in plants remain unclear. In the present study, hydrogen-rich water (HRW) was used to characterize the physiological roles of H2 in enhancing the tolerance of Brassica campestris against cadmium (Cd). The results showed that both 50 μM CdCl2 and 50%-saturated HRW induced an increase of endogenous H2 in Brassica campestris seedlings, and HRW alleviated Cd toxicity related to growth inhibition and oxidative damage. Seedlings supplied with HRW exhibited increased root length and reduced lipid peroxidation, similar to plants receiving GSH post-treatment. Additionally, seedlings post-treated with HRW accumulated higher levels of reduced glutathione (GSH) and ascorbic acid (AsA) and showed increased GST and GPX activities in roots. Molecular evidence illustrated that the expression of genes such as GS, GR1 and GR2, which were down-regulated following the addition of Cd, GSH or BSO, could be reversed to varying degrees by the addition of HRW. Based on these results, it could be proposed that H2 might be an important regulator for enhancing the tolerance of Brassica campestris seedlings against Cd, mainly by governing reduced glutathione homeostasis.

  7. Sensitive and specific detection of Xanthomonas campestris pv campestris by PCR using species-specific primers based on hrpF gene sequences.

    Science.gov (United States)

    Park, Young Jin; Lee, Byoung Moo; Ho-Hahn, Jang; Lee, Gil Bok; Park, Dong Suk

    2004-01-01

    A sensitive and specific assay was developed to detect bacterial black rot of crucifers caused by Xanthomonas campestris pv. campestris (X. c. pv. campestris), in cabbage seed and plant. Primers XCF and XCR from hrpF homologous to nolX, host recognition protein, were used to amplify a 525 bp DNA fragment. PCR technique was applied to detect the pathogen in naturally infected seed and plant of cabbage. The PCR product was only produced from X. c. pv. campestris among 40 isolates of Xanthomonas strains, Escherichia coli (O157:H7), Pectobacterium carotovorum subsp. carotovorum, and other reference bacteria.

  8. Antihypertensive and vasorelaxant effects of aqueous extract of Artemisia campestris L. from Eastern Morocco.

    Science.gov (United States)

    Dib, Ikram; Tits, Monique; Angenot, Luc; Wauters, Jean Noel; Assaidi, Asmae; Mekhfi, Hassane; Aziz, Mohammed; Bnouham, Mohammed; Legssyer, Abdelkhaleq; Frederich, Michel; Ziyyat, Abderrahim

    2017-07-12

    Artemisia campestris L. (Asteraceae) has many traditional uses, among which treatment of diabetes and hypertension. This study was conducted in order to confirm the antihypertensive and hypotensive effects of A. campestris L. aqueous extract (AcAE) and to explore the underlying mechanism of action of its vasorelaxant effect, besides the acute toxicity. Also, the chemical composition of AcAE was investigated. the chemical content of AcAE was determined by using HPLC and NMR techniques. The antihypertensive effect was assessed indirectly by tail-cuff method on L-NAME induced hypertensive rats, while the hypotensive action was monitored intravenously by invasive method on normotensive rats. The vasorelaxant effect and vascular mechanism of action were studied in the presence of antagonists and blockers on aorta isolated from normotensive rats. On the other side, the acute toxicity was studied by oral feeding of extract to the mice. The global phytochemical profile of AcAE reveals the presence of several polyphenols as main components. A. campestris L. infusion was characterized by mono- and di-cinnamoyl compounds, with 3,5-dicaffeoylquinic (isochlorogenic A) acid being the main compound, followed by 5-caffeoylquinic (chlorogenic) acid. Vicenin-2 (apigenin 6,8-di-C-glucoside) appeared to be the most abundant compound among flavonoids. The daily treatment with AcAE at 150mg/kg/day prevented the installation of hypertension on L-NAME hypertensive rats, and reduced SBP from 172mmHg up to 144mmHg. At the dose 40mg/kg, AcAE provoked reduction of systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP), without affecting the heart rate. Also, AcAE (10 -2 -2mg/ml) relaxed the precontracted aorta by 95.8±1.3%. The denudation and preincubation of aorta with atropine, calmidazolium, L-NAME, hydroxycobalamin, ODQ, 8-RP-Br-PET-cGMP, thapsigargin and verapamil attenuated the vasorelaxant response, while the pre-treatment with 4-AP, TEA, glibenclamide and BaCl 2 did not

  9. Plate tectonic regulation of global marine animal diversity

    Science.gov (United States)

    Zaffos, Andrew; Finnegan, Seth

    2017-01-01

    Valentine and Moores [Valentine JW, Moores EM (1970) Nature 228:657–659] hypothesized that plate tectonics regulates global biodiversity by changing the geographic arrangement of continental crust, but the data required to fully test the hypothesis were not available. Here, we use a global database of marine animal fossil occurrences and a paleogeographic reconstruction model to test the hypothesis that temporal patterns of continental fragmentation have impacted global Phanerozoic biodiversity. We find a positive correlation between global marine invertebrate genus richness and an independently derived quantitative index describing the fragmentation of continental crust during supercontinental coalescence–breakup cycles. The observed positive correlation between global biodiversity and continental fragmentation is not readily attributable to commonly cited vagaries of the fossil record, including changing quantities of marine rock or time-variable sampling effort. Because many different environmental and biotic factors may covary with changes in the geographic arrangement of continental crust, it is difficult to identify a specific causal mechanism. However, cross-correlation indicates that the state of continental fragmentation at a given time is positively correlated with the state of global biodiversity for tens of millions of years afterward. There is also evidence to suggest that continental fragmentation promotes increasing marine richness, but that coalescence alone has only a small negative or stabilizing effect. Together, these results suggest that continental fragmentation, particularly during the Mesozoic breakup of the supercontinent Pangaea, has exerted a first-order control on the long-term trajectory of Phanerozoic marine animal diversity. PMID:28507147

  10. Plate tectonic regulation of global marine animal diversity

    Science.gov (United States)

    Zaffos, Andrew; Finnegan, Seth; Peters, Shanan E.

    2017-05-01

    Valentine and Moores [Valentine JW, Moores EM (1970) Nature 228:657-659] hypothesized that plate tectonics regulates global biodiversity by changing the geographic arrangement of continental crust, but the data required to fully test the hypothesis were not available. Here, we use a global database of marine animal fossil occurrences and a paleogeographic reconstruction model to test the hypothesis that temporal patterns of continental fragmentation have impacted global Phanerozoic biodiversity. We find a positive correlation between global marine invertebrate genus richness and an independently derived quantitative index describing the fragmentation of continental crust during supercontinental coalescence-breakup cycles. The observed positive correlation between global biodiversity and continental fragmentation is not readily attributable to commonly cited vagaries of the fossil record, including changing quantities of marine rock or time-variable sampling effort. Because many different environmental and biotic factors may covary with changes in the geographic arrangement of continental crust, it is difficult to identify a specific causal mechanism. However, cross-correlation indicates that the state of continental fragmentation at a given time is positively correlated with the state of global biodiversity for tens of millions of years afterward. There is also evidence to suggest that continental fragmentation promotes increasing marine richness, but that coalescence alone has only a small negative or stabilizing effect. Together, these results suggest that continental fragmentation, particularly during the Mesozoic breakup of the supercontinent Pangaea, has exerted a first-order control on the long-term trajectory of Phanerozoic marine animal diversity.

  11. Chromosome Map of Xanthomonas campestris pv. campestris 17 with Locations of Genes Involved in Xanthan Gum Synthesis and Yellow Pigmentation

    OpenAIRE

    Tseng, Yi-Hsiung; Choy, Ka-Tim; Hung, Chih-Hsin; Lin, Nien-Tsung; Liu, Jane-Yu; Lou, Chih-Hong; Yang, Bih-Ying; Wen, Fu-Shyan; Weng, Shu-Fen; Wu, Jung-Rung

    1999-01-01

    No plasmid was detected in Xanthomonas campestris pv. campestris 17, a strain of the causative agent of black rot in cruciferous plants isolated in Taiwan. Its chromosome was cut by PacI, PmeI, and SwaI into five, two, and six fragments, respectively, and a size of 4.8 Mb was estimated by summing the fragment lengths in these digests. Based on the data obtained from partial digestion and Southern hybridization using probes common to pairs of the overlapping fragments or prepared from linking ...

  12. Aflatoxin regulations in a network of global maize trade.

    Directory of Open Access Journals (Sweden)

    Felicia Wu

    Full Text Available Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000-2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B(1, B(2, G(1, and G(2 differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards.

  13. Local and global responses in complex gene regulation networks

    Science.gov (United States)

    Tsuchiya, Masa; Selvarajoo, Kumar; Piras, Vincent; Tomita, Masaru; Giuliani, Alessandro

    2009-04-01

    An exacerbated sensitivity to apparently minor stimuli and a general resilience of the entire system stay together side-by-side in biological systems. This apparent paradox can be explained by the consideration of biological systems as very strongly interconnected network systems. Some nodes of these networks, thanks to their peculiar location in the network architecture, are responsible for the sensitivity aspects, while the large degree of interconnection is at the basis of the resilience properties of the system. One relevant feature of the high degree of connectivity of gene regulation networks is the emergence of collective ordered phenomena influencing the entire genome and not only a specific portion of transcripts. The great majority of existing gene regulation models give the impression of purely local ‘hard-wired’ mechanisms disregarding the emergence of global ordered behavior encompassing thousands of genes while the general, genome wide, aspects are less known. Here we address, on a data analysis perspective, the discrimination between local and global scale regulations, this goal was achieved by means of the examination of two biological systems: innate immune response in macrophages and oscillating growth dynamics in yeast. Our aim was to reconcile the ‘hard-wired’ local view of gene regulation with a global continuous and scalable one borrowed from statistical physics. This reconciliation is based on the network paradigm in which the local ‘hard-wired’ activities correspond to the activation of specific crucial nodes in the regulation network, while the scalable continuous responses can be equated to the collective oscillations of the network after a perturbation.

  14. Acetyl-CoA carboxylase regulates global histone acetylation.

    Science.gov (United States)

    Galdieri, Luciano; Vancura, Ales

    2012-07-06

    Histone acetylation depends on intermediary metabolism for supplying acetyl-CoA in the nucleocytosolic compartment. However, because nucleocytosolic acetyl-CoA is also used for de novo synthesis of fatty acids, histone acetylation and synthesis of fatty acids compete for the same acetyl-CoA pool. The first and rate-limiting reaction in de novo synthesis of fatty acids is carboxylation of acetyl-CoA to form malonyl-CoA, catalyzed by acetyl-CoA carboxylase. In yeast Saccharomyces cerevisiae, acetyl-CoA carboxylase is encoded by the ACC1 gene. In this study, we show that attenuated expression of ACC1 results in increased acetylation of bulk histones, globally increased acetylation of chromatin histones, and altered transcriptional regulation. Together, our data indicate that Acc1p activity regulates the availability of acetyl-CoA for histone acetyltransferases, thus representing a link between intermediary metabolism and epigenetic mechanisms of transcriptional regulation.

  15. studies on seed transmissfon of xanthomqnas campestris pv

    African Journals Online (AJOL)

    1993-03-03

    Mar 3, 1993 ... Centro International de Agricultura. Tropical. Pastor Corrales, M.A., S.A. Beebe and FJ. Correa, 1981. Comparing two inoculation techniques for evaluating resistance in beans to Xanthomonas campestris pv phaseoli. in: Proceedings of the Fifth international. Conference on Plant Pathogenic Bacteria,. 1981 ...

  16. Global self-regulation of the cellular metabolic structure.

    Directory of Open Access Journals (Sweden)

    Ildefonso M De la Fuente

    Full Text Available BACKGROUND: Different studies have shown that cellular enzymatic activities are able to self-organize spontaneously, forming a metabolic core of reactive processes that remain active under different growth conditions while the rest of the molecular catalytic reactions exhibit structural plasticity. This global cellular metabolic structure appears to be an intrinsic characteristic common to all cellular organisms. Recent work performed with dissipative metabolic networks has shown that the fundamental element for the spontaneous emergence of this global self-organized enzymatic structure could be the number of catalytic elements in the metabolic networks. METHODOLOGY/PRINCIPAL FINDINGS: In order to investigate the factors that may affect the catalytic dynamics under a global metabolic structure characterized by the presence of metabolic cores we have studied different transitions in catalytic patterns belonging to a dissipative metabolic network. The data were analyzed using non-linear dynamics tools: power spectra, reconstructed attractors, long-term correlations, maximum Lyapunov exponent and Approximate Entropy; and we have found the emergence of self-regulation phenomena during the transitions in the metabolic activities. CONCLUSIONS/SIGNIFICANCE: The analysis has also shown that the chaotic numerical series analyzed correspond to the fractional Brownian motion and they exhibit long-term correlations and low Approximate Entropy indicating a high level of predictability and information during the self-regulation of the metabolic transitions. The results illustrate some aspects of the mechanisms behind the emergence of the metabolic self-regulation processes, which may constitute an important property of the global structure of the cellular metabolism.

  17. Effector-triggered innate immunity contributes Arabidopsis resistance to Xanthomonas campestris.

    Science.gov (United States)

    Rong, Wei; Feng, Feng; Zhou, Jianmin; He, Chaozu

    2010-11-01

    Xanthomonas campestris pv. campestris, the causal agent of black rot disease, depends on its type III secretion system (TTSS) to infect cruciferous plants, including Brassica oleracea, B. napus and Arabidopsis. Previous studies on the Arabidopsis-Pseudomonas syringae model pathosystem have indicated that a major function of TTSS from virulent bacteria is to suppress host defences triggered by pathogen-associated molecular patterns. Similar analyses have not been made for the Arabidopsis-X. campestris pv. campestris pathosystem. In this study, we report that X. campestris pv. campestris strain 8004, which is modestly pathogenic on Arabidopsis, induces strong defence responses in Arabidopsis in a TTSS-dependent manner. Furthermore, the induction of defence responses and disease resistance to X. campestris pv. campestris strain 8004 requires NDR1 (NON-RACE-SPECIFIC DISEASE RESISTANCE1), RAR1 (required for Mla12 resistance) and SGT1b (suppressor of G2 allele of skp1), suggesting that effector-triggered immunity plays a large role in resistance to this strain. Consistent with this notion, AvrXccC, an X. campestris pv. campestris TTSS effector protein, induces PR1 expression and confers resistance in Arabidopsis in a RAR1- and SGT1b-dependent manner. In rar1 and sgt1b mutants, AvrXccC acts as a virulence factor, presumably because of impaired resistance gene function. © 2010 The Authors. Molecular Plant Pathology © 2010 BSPP and Blackwell Publishing Ltd.

  18. Real Time Live Imaging of Phytopathogenic Bacteria Xanthomonas campestris pv. campestris MAFF106712 in ‘Plant Sweet Home’

    Science.gov (United States)

    Akimoto-Tomiyama, Chiharu; Furutani, Ayako; Ochiai, Hirokazu

    2014-01-01

    Xanthomonas is one of the most widespread phytobacteria, causing diseases on a variety of agricultural plants. To develop novel control techniques, knowledge of bacterial behavior inside plant cells is essential. Xanthomonas campestris pv. campestris, a vascular pathogen, is the causal agent of black rot on leaves of Brassicaceae, including Arabidopsis thaliana. Among the X. campestris pv. campestris stocks in the MAFF collection, we selected XccMAFF106712 as a model compatible pathogen for the A. thaliana reference ecotype Columbia (Col-0). Using modified green fluorescent protein (AcGFP) as a reporter, we observed real time XccMAFF106712 colonization in planta with confocal microscopy. AcGFP-expressing bacteria colonized the inside of epidermal cells and the apoplast, as well as the xylem vessels of the vasculature. In the case of the type III mutant, bacteria colonization was never detected in the xylem vessel or apoplast, though they freely enter the xylem vessel through the wound. After 9 days post inoculation with XccMAFF106712, the xylem vessel became filled with bacterial aggregates. This suggests that Xcc colonization can be divided into main four steps, (1) movement in the xylem vessel, (2) movement to the next cell, (3) adhesion to the host plant cells, and (4) formation of bacterial aggregates. The type III mutant abolished at least steps (1) and (2). Better understanding of Xcc colonization is essential for development of novel control techniques for black rot. PMID:24736478

  19. Global analysis of neuronal phosphoproteome regulation by chondroitin sulfate proteoglycans.

    Directory of Open Access Journals (Sweden)

    Panpan Yu

    Full Text Available Chondroitin sulfate proteoglycans (CSPGs are major components of the extracellular matrix which mediate inhibition of axonal regeneration after injury to the central nervous system (CNS. Several neuronal receptors for CSPGs have recently been identified; however, the signaling pathways by which CSPGs restrict axonal growth are still largely unknown. In this study, we applied quantitative phosphoproteomics to investigate the global changes in protein phosphorylation induced by CSPGs in primary neurons. In combination with isobaric Tags for Relative and Absolute Quantitation (iTRAQ labeling, strong cation exchange chromatography (SCX fractionation, immobilized metal affinity chromatography (IMAC and LC-MS/MS, we identified and quantified 2214 unique phosphopeptides corresponding to 1118 phosphoproteins, with 118 changing significantly in abundance with CSPG treatment. The proteins that were regulated by CSPGs included key components of synaptic vesicle trafficking, axon guidance mediated by semaphorins, integrin signaling, cadherin signaling and EGF receptor signaling pathways. A significant number of the regulated proteins are cytoskeletal and related proteins that have been implicated in regulating neurite growth. Another highly represented protein category regulated by CSPGs is nucleic acid binding proteins involved in RNA post-transcriptional regulation. Together, by screening the overall phosphoproteome changes induced by CSPGs, this data expand our understanding of CSPG signaling, which provides new insights into development of strategies for overcoming CSPG inhibition and promoting axonal regeneration after CNS injury.

  20. Immunofluorescence microscopy and dilution-plating for the detection of Xanthomonas campestris pv. campestris in crucifer seeds : methods to determine seed health and seed infection

    NARCIS (Netherlands)

    Franken, A.A.J.M.

    1992-01-01

    Black rot is one of the most threatening diseases of crucifers. The causal agent of this disease is the bacterium Xanthomonas campestris pv. campestris . The bacterium attacks all cultivated brassicas, radishes and numerous weeds, and is able to survive on

  1. Genome wide transcription start sites analysis of Xanthomonas campestris pv. campestris B100 with insights into the gum gene cluster directing the biosynthesis of the exopolysaccharide xanthan.

    Science.gov (United States)

    Alkhateeb, Rabeaa S; Vorhölter, Frank-Jörg; Rückert, Christian; Mentz, Almut; Wibberg, Daniel; Hublik, Gerd; Niehaus, Karsten; Pühler, Alfred

    2016-05-10

    Xanthomonas campestris pv. campestris (Xcc) is the major producer of the exopolysaccharide xanthan, the commercially most important natural polysaccharide of microbial origin. The current work provides deeper insights into the yet uncharacterized transcriptomic features of the xanthan producing strain Xcc-B100. Towards this goal, RNA sequencing of a library based on the selective enrichment of the 5' ends of native transcripts was performed. This approach resulted in the genome wide identification of 3067 transcription start sites (TSSs) that were further classified based on their genomic positions. Among them, 1545 mapped upstream of an actively transcribed CDS and 1363 were classified as novel TSSs representing antisense, internal, and TSSs belonging to previously unidentified genomic features. Analyzing the transcriptional strength of primary and antisense TSSs revealed that in some instances antisense transcription seemed to be initiated at a higher level than its sense counterpart. Mapping the exact positions of TSSs aided in the identification of promoter consensus motifs, ribosomal binding sites, and enhanced the genome annotation of 159 in silico predicted translational start (TLS) sites. The global view on length distribution of the 5' untranslated regions (5'-UTRs) deduced from the data pointed to the occurrence of leaderless transcripts and transcripts with unusually long 5'-UTRs, in addition to identifying seven putative riboswitch elements for Xcc-B100. Concerning the biosynthesis of xanthan, we focused on the transcriptional organization of the gum gene cluster. Under the conditions tested, we present evidence for a complex transcription pattern of the gum genes with multiple TSSs and an obvious considerable role of antisense transcription. The gene gumB, encoding an outer membrane xanthan exporter, is presented here as an example for genes that possessed a strong antisense TSS. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Mutation of the gene encoding a major outer-membrane protein in Xanthomonas campestris pv. campestris causes pleiotropic effects, including loss of pathogenicity.

    Science.gov (United States)

    Chen, Yih-Yuan; Wu, Chieh-Hao; Lin, Juey-Wen; Weng, Shu-Fen; Tseng, Yi-Hsiung

    2010-09-01

    Xanthomonas campestris pv. campestris (Xcc) is the phytopathogen that causes black rot in crucifers. The xanthan polysaccharide and extracellular enzymes produced by this organism are virulence factors, the expression of which is upregulated by Clp (CRP-like protein) and DSF (diffusible signal factor), which is synthesized by RpfF. It is also known that biofilm formation/dispersal, regulated by the effect of controlled synthesis of DSF on cell-cell signalling, is required for virulence. Furthermore, a deficiency in DSF causes cell aggregation with concomitant production of a gum-like substance that can be dispersed by addition of DSF or digested by exogenous endo-beta-1,4-mannanase expressed by Xcc. In this study, Western blotting of proteins from a mopB mutant (XcMopB) showed Xcc MopB to be the major outer-membrane protein (OMP); Xcc MopB shared over 97 % identity with homologues from other members of Xanthomonas. Similarly to the rpfF mutant, XcMopB formed aggregates with simultaneous production of a gummy substance, but these aggregates could not be dispersed by DSF or endo-beta-1,4-mannanase, indicating that different mechanisms were involved in aggregation. In addition, XcMopB showed surface deformation, altered OMP composition, impaired xanthan production, increased sensitivity to stressful conditions including SDS, elevated temperature and changes in pH, reduced adhesion and motility and defects in pathogenesis. The finding that the major OMP is required for pathogenicity is unprecedented in phytopathogenic bacteria.

  3. Cell shape regulates global histone acetylation in human mammaryepithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Le Beyec, Johanne; Xu, Ren; Lee, Sun-Young; Nelson, Celeste M.; Rizki, Aylin; Alcaraz, Jordi; Bissell, Mina J.

    2007-02-28

    Extracellular matrix (ECM) regulates cell morphology and gene expression in vivo; these relationships are maintained in three-dimensional (3D) cultures of mammary epithelial cells. In the presence of laminin-rich ECM (lrECM), mammary epithelial cells round up and undergo global histone deacetylation, a process critical for their functional differentiation. However, it remains unclear whether lrECM-dependent cell rounding and global histone deacetylation are indeed part of a common physical-biochemical pathway. Using 3D cultures as well as nonadhesive and micropatterned substrata, here we showed that the cell 'rounding' caused by lrECM was sufficient to induce deacetylation of histones H3 and H4 in the absence of biochemical cues. Microarray and confocal analysis demonstrated that this deacetylation in 3D culture is associated with a global increase in chromatin condensation and a reduction in gene expression. Whereas cells cultured on plastic substrata formed prominent stress fibers, cells grown in 3D lrECM or on micropatterns lacked these structures. Disruption of the actin cytoskeleton with cytochalasin D phenocopied the lrECM-induced cell rounding and histone deacetylation. These results reveal a novel link between ECM-controlled cell shape and chromatin structure, and suggest that this link is mediated by changes in the actin cytoskeleton.

  4. Xanthan production by Xanthomonas campestris using whey permeate medium.

    Science.gov (United States)

    Savvides, A L; Katsifas, E A; Hatzinikolaou, D G; Karagouni, A D

    2012-08-01

    Xanthan gum is a polysaccharide that is widely used as stabilizer and thickener with many industrial applications in food industry. Our aim was to estimate the ability of Xanthomonas campestris ATCC 13951 for the production of xanthan gum by using whey as a growth medium, a by-product of dairy industry. X. campestris ATCC 13951 has been studied in batch cultures using a complex medium for the determination of the optimal concentration of glucose, galactose and lactose. In addition, whey was used under various treatment procedures (de-proteinated, partially hydrolyzed by β-lactamase and partially hydrolyzed and de-proteinated) as culture medium, to study the production of xanthan in a 2 l bioreactor with constant stirring and aeration. A production of 28 g/l was obtained when partially hydrolysed β-lactamase was used, which proved to be one of the highest xanthan gum production reported so far. At the same time, an effort has been made for the control and selection of the most appropriate procedure for the preservation of the strain and its use as inoculant in batch cultures, without loss of its viability and its capability of xanthan gum production. The pre-treatment of whey (whey permeate medium hydrolyzed, WPH) was very important for the production of xanthan by the strain X. campestris ATCC 13951 during batch culture conditions in a 2 l bioreactor. Preservation methods such as lyophilization, cryopreservation at various glycerol solution and temperatures have been examined. The results indicated that the best preservation method for the producing strain X. campestris ATCC 13951 was the lyophilization. Taking into account that whey permeate is a low cost by-product of the dairy industry, the production of xanthan achieved under the studied conditions was considered very promising for industrial application.

  5. Global parameter estimation for thermodynamic models of transcriptional regulation.

    Science.gov (United States)

    Suleimenov, Yerzhan; Ay, Ahmet; Samee, Md Abul Hassan; Dresch, Jacqueline M; Sinha, Saurabh; Arnosti, David N

    2013-07-15

    Deciphering the mechanisms involved in gene regulation holds the key to understanding the control of central biological processes, including human disease, population variation, and the evolution of morphological innovations. New experimental techniques including whole genome sequencing and transcriptome analysis have enabled comprehensive modeling approaches to study gene regulation. In many cases, it is useful to be able to assign biological significance to the inferred model parameters, but such interpretation should take into account features that affect these parameters, including model construction and sensitivity, the type of fitness calculation, and the effectiveness of parameter estimation. This last point is often neglected, as estimation methods are often selected for historical reasons or for computational ease. Here, we compare the performance of two parameter estimation techniques broadly representative of local and global approaches, namely, a quasi-Newton/Nelder-Mead simplex (QN/NMS) method and a covariance matrix adaptation-evolutionary strategy (CMA-ES) method. The estimation methods were applied to a set of thermodynamic models of gene transcription applied to regulatory elements active in the Drosophila embryo. Measuring overall fit, the global CMA-ES method performed significantly better than the local QN/NMS method on high quality data sets, but this difference was negligible on lower quality data sets with increased noise or on data sets simplified by stringent thresholding. Our results suggest that the choice of parameter estimation technique for evaluation of gene expression models depends both on quality of data, the nature of the models [again, remains to be established] and the aims of the modeling effort. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Characterization of the Xanthomonas campestris pv. campestris lipopolysaccharide substructures essential for elicitation of an oxidative burst in tobacco cells.

    Science.gov (United States)

    Braun, Sebastian G; Meyer, Andreas; Holst, Otto; Pühler, Alfred; Niehaus, Karsten

    2005-07-01

    The lipopolysaccharides (LPS) of gram-negative bacteria are essential for perception of pathogens by animals and plants. To identify the LPS substructure or substructures recognized by plants, we isolated water-phase (w)LPS from different Xanthomonas campestris pv. campestris mutants and analyzed their sugar content and ability to elicit an oxidative burst in tobacco cell cultures. The different wLPS species are characterized by lacking repetitive subunits of the O-antigen, the complete O-antigen, or even most of the core region. Because loss of lipid A would be lethal to bacteria, pure lipid A was obtained from X. campestris pv. campestris wild-type wLPS by chemical hydrolysis. The elicitation experiments with tobacco cell cultures revealed that LPS detection is dependent on the bioavailability of the amphiphilic wLPS, which can form micelles in an aqueous environment. By adding deoxycholate to prevent micelle formation, all of the tested wLPS species showed elicitation capability, whereas the lipid A alone was not able to trigger an oxidative burst or calcium transients in tobacco cell cultures. These results suggest that the LPS substructure recognized by tobacco cells is localized in the inner core region of the LPS, consisting of glucose, galacturonic acid, and 3-deoxy-d-manno-oct-2-ulosonic acids. Although lipid A alone seems to be insufficient to induce an oxidative burst in tobacco cell cultures, it cannot be ruled out that lipid A or the glucosamine backbone may be important in combination with the inner core structures.

  7. Model-based redesign of global transcription regulation

    Science.gov (United States)

    Carrera, Javier; Rodrigo, Guillermo; Jaramillo, Alfonso

    2009-01-01

    Synthetic biology aims to the design or redesign of biological systems. In particular, one possible goal could be the rewiring of the transcription regulation network by exchanging the endogenous promoters. To achieve this objective, we have adapted current methods to the inference of a model based on ordinary differential equations that is able to predict the network response after a major change in its topology. Our procedure utilizes microarray data for training. We have experimentally validated our inferred global regulatory model in Escherichia coli by predicting transcriptomic profiles under new perturbations. We have also tested our methodology in silico by providing accurate predictions of the underlying networks from expression data generated with artificial genomes. In addition, we have shown the predictive power of our methodology by obtaining the gene profile in experimental redesigns of the E. coli genome, where rewiring the transcriptional network by means of knockouts of master regulators or by upregulating transcription factors controlled by different promoters. Our approach is compatible with most network inference methods, allowing to explore computationally future genome-wide redesign experiments in synthetic biology. PMID:19188257

  8. Neoliberalism and the regulation of global labor mobility

    NARCIS (Netherlands)

    Overbeek, H.W.

    2002-01-01

    Globalization involves the international expansion of market relations and the global pursuit of economic liberalism. The essential factor in this process is commodification, including the commodification of human labor. Globalization integrates an increasing proportion of the world population

  9. An Essential Regulatory System Originating from Polygenic Transcriptional Rewiring of PhoP-PhoQ of Xanthomonas campestris.

    Science.gov (United States)

    Peng, Bao-Yu; Pan, Yue; Li, Ru-Jiao; Wei, Jin-Wei; Liang, Fang; Wang, Li; Wang, Fang-Fang; Qian, Wei

    2017-08-01

    How essential, regulatory genes originate and evolve is intriguing because mutations of these genes not only lead to lethality in organisms, but also have pleiotropic effects since they control the expression of multiple downstream genes. Therefore, the evolution of essential, regulatory genes is not only determined by genetic variations of their own sequences, but also by the biological function of downstream genes and molecular mechanisms of regulation. To understand the origin of essential, regulatory genes, experimental dissection of the complete regulatory cascade is needed. Here, we provide genetic evidences to reveal that PhoP-PhoQ is an essential two-component signal transduction system in the gram-negative bacterium Xanthomonas campestris, but that its orthologs in other bacteria belonging to Proteobacteria are nonessential. Mutational, biochemical, and chromatin immunoprecipitation together with high-throughput sequencing analyses revealed that phoP and phoQ of X. campestris and its close relative Pseudomonas aeruginosa are replaceable, and that the consensus binding motifs of the transcription factor PhoP are also highly conserved. PhoP Xcc in X. campestris regulates the transcription of a number of essential, structural genes by directly binding to cis-regulatory elements (CREs); however, these CREs are lacking in the orthologous essential, structural genes in P. aeruginosa, and thus the regulatory relationships between PhoP Pae and these downstream essential genes are disassociated. Our findings suggested that the recruitment of regulatory proteins by critical structural genes via transcription factor-CRE rewiring is a driving force in the origin and functional divergence of essential, regulatory genes. Copyright © 2017 by the Genetics Society of America.

  10. Genetic Diversity of Xanthomonas campestris pv. vitians, the Causal Agent of Bacterial Leafspot of Lettuce.

    Science.gov (United States)

    Barak, Jeri D; Gilbertson, Robert L

    2003-05-01

    ABSTRACT Bacterial leafspot of lettuce (BLS), caused by Xanthomonas campes-tris pv. vitians, has become more prevalent in many lettuce-growing areas of the world over the past decade. To gain insight into the nature of these outbreaks, the genetic variation in X. campestris pv. vitians strains from different geographical locations was examined. All strains were first tested for pathogenicity on lettuce plants, and then genetic diversity was assessed using (i) gas-chromatographic analysis of bacterial fatty acids, (ii) polymerase chain reaction analysis of repetitive DNA sequences (rep-PCR), (iii) DNA sequence analysis of the internal transcribed spacer region 1 (ITS1) of the ribosomal RNA, (iv) restriction fragment length polymorphism (RFLP) analysis of total genomic DNA with a repetitive DNA probe, and (v) detection and partial characterization of plasmid DNA. Fatty acid analysis identified all pathogenic strains as X. campestris, but did not consistently identify all the strains as X. campestris pv. vitians. The rep-PCR fingerprints and ITS1 sequences of all pathogenic X. campestris pv. vitians strains examined were identical, and distinct from those of the other X. campestris pathovars. Thus, these characteristics did not reveal genetic diversity among X. campestris pv. vitians strains, but did allow for differentiation of X. campestris pathovars. Genetic diversity among X. campestris pv. vitians strains was revealed by RFLP analysis with a repetitive DNA probe and by characterization of plasmid DNA. This diversity was greatest among strains from different geographical regions, although diversity among strains from the same location also was detected. The results of this study suggest that these X. campestris pv. vitians strains are not clonal, but comprise a relatively homogeneous group.

  11. Xanthomonas campestris attenuates virulence by sensing light through a bacteriophytochrome photoreceptor.

    Science.gov (United States)

    Bonomi, Hernán R; Toum, Laila; Sycz, Gabriela; Sieira, Rodrigo; Toscani, Andrés M; Gudesblat, Gustavo E; Leskow, Federico C; Goldbaum, Fernando A; Vojnov, Adrián A; Malamud, Florencia

    2016-11-01

    Phytochromes constitute a major photoreceptor family found in plants, algae, fungi, and prokaryotes, including pathogens. Here, we report that Xanthomonas campestris pv. campestris (Xcc), the causal agent of black rot disease which affects cruciferous crops worldwide, codes for a functional bacteriophytochrome (XccBphP). XccBphP possesses an N-terminal PAS2-GAF-PHY photosensory domain triad and a C-terminal PAS9 domain as its output module. Our results show that illumination of Xcc, prior to plant infection, attenuates its virulence in an XccBphP-dependent manner. Moreover, in response to light, XccBphP downregulates xanthan exopolysaccharide production and biofilm formation, two known Xcc virulence factors. Furthermore, the XccbphP null mutant shows enhanced virulence, similar to that of dark-adapted Xcc cultures. Stomatal aperture regulation and callose deposition, both well-established plant defense mechanisms against bacterial pathogens, are overridden by the XccbphP strain. Additionally, an RNA-Seq analysis reveals that far-red light or XccBphP overexpression produces genomewide transcriptional changes, including the inhibition of several Xcc virulence systems. Our findings indicate that Xcc senses light through XccBphP, eliciting bacterial virulence attenuation via downregulation of bacterial virulence factors. The capacity of XccBphP to respond to light both in vitro and in vivo was abolished by a mutation on the conserved Cys13 residue. These results provide evidence for a novel bacteriophytochrome function affecting an infectious process. © 2016 The Authors.

  12. Expression of sweet pepper Hrap gene in banana enhances resistance to Xanthomonas campestris pv. musacearum.

    Science.gov (United States)

    Tripathi, Leena; Mwaka, Henry; Tripathi, Jaindra Nath; Tushemereirwe, Wilberforce Kateera

    2010-11-01

    Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum, is the most devastating disease of banana in the Great Lakes region of Africa. The pathogen's rapid spread has threatened the livelihood of millions of Africans who rely on banana fruit for food security and income. The disease is very destructive, infecting all banana varieties, including both East African Highland bananas and exotic types of banana. In the absence of natural host plant resistance among banana cultivars, the constitutive expression of the hypersensitivity response-assisting protein (Hrap) gene from sweet pepper (Capsicum annuum) was evaluated for its ability to confer resistance to BXW. Transgenic lines expressing the Hrap gene under the regulation of the constitutive CaMV35S promoter were generated using embryogenic cell suspensions of two banana cultivars: 'Sukali Ndiizi' and 'Mpologoma'. These lines were characterized by molecular analysis, and were challenged with Xanthomonas campestris pv. musacearum to analyse the efficacy of the Hrap gene against BXW. The majority of transgenic lines (six of eight) expressing Hrap did not show any symptoms of infection after artificial inoculation of potted plants in the screenhouse, whereas control nontransgenic plants showed severe symptoms resulting in complete wilting. This study demonstrates that the constitutive expression of the sweet pepper Hrap gene in banana results in enhanced resistance to BXW. We describe the development of transgenic banana varieties resistant to BXW, which will boost the arsenal available to fight this epidemic disease and save livelihoods in the Great Lakes region of East and Central Africa. © 2010 IITA/NARO. Molecular Plant Pathology © 2010 BSPP and Blackwell Publishing Ltd.

  13. Crystallization and Preliminary Crystallographic Characterization of GumK, A Membrane-Associated Gluocuronosyltransferase from Xanthomonas campestris Required for Xanthan Polysaccharide Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Barreras,M.; Bianchet, M.; Ielpi, L.; Tong, L.

    2006-01-01

    GumK is a membrane-associated inverting glucuronosyltransferase that is part of the biosynthetic route of xanthan, an industrially important exopolysaccharide produced by Xanthomonas campestris. The enzyme catalyzes the fourth glycosylation step in the pentasaccharide-P-P-polyisoprenyl assembly, an oligosaccharide diphosphate lipid intermediate in xanthan biosynthesis. GumK has marginal homology to other glycosyltransferases (GTs). It belongs to the CAZy family GT 70, for which no structure is currently available, and indirect biochemical evidence suggests that it also belongs to the GT-B structural superfamily. Crystals of recombinant GumK from X. campestris have been grown that diffract to 1.9 {angstrom} resolution. Knowledge of the crystal structure of GumK will help in understanding xanthan biosynthesis and its regulation and will also allow a subsequent rational approach to enzyme design and engineering. The multiwavelength anomalous diffraction approach will be used to solve the phase problem.

  14. Crystallization and preliminary crystallographic characterization of GumK, a membrane-associated glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis.

    Science.gov (United States)

    Barreras, Máximo; Bianchet, Mario A; Ielpi, Luis

    2006-09-01

    GumK is a membrane-associated inverting glucuronosyltransferase that is part of the biosynthetic route of xanthan, an industrially important exopolysaccharide produced by Xanthomonas campestris. The enzyme catalyzes the fourth glycosylation step in the pentasaccharide-P-P-polyisoprenyl assembly, an oligosaccharide diphosphate lipid intermediate in xanthan biosynthesis. GumK has marginal homology to other glycosyltransferases (GTs). It belongs to the CAZy family GT 70, for which no structure is currently available, and indirect biochemical evidence suggests that it also belongs to the GT-B structural superfamily. Crystals of recombinant GumK from X. campestris have been grown that diffract to 1.9 A resolution. Knowledge of the crystal structure of GumK will help in understanding xanthan biosynthesis and its regulation and will also allow a subsequent rational approach to enzyme design and engineering. The multiwavelength anomalous diffraction approach will be used to solve the phase problem.

  15. Crystallization and preliminary crystallographic characterization of GumK, a membrane-associated glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Barreras, Máximo [Fundación Instituto Leloir, CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1405BWE Buenos Aires (Argentina); Bianchet, Mario A. [Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Ielpi, Luis, E-mail: lielpi@leloir.org.ar [Fundación Instituto Leloir, CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1405BWE Buenos Aires (Argentina)

    2006-09-01

    Crystallization of a membrane-associated glucuronosyltransferase. GumK is a membrane-associated inverting glucuronosyltransferase that is part of the biosynthetic route of xanthan, an industrially important exopolysaccharide produced by Xanthomonas campestris. The enzyme catalyzes the fourth glycosylation step in the pentasaccharide-P-P-polyisoprenyl assembly, an oligosaccharide diphosphate lipid intermediate in xanthan biosynthesis. GumK has marginal homology to other glycosyltransferases (GTs). It belongs to the CAZy family GT 70, for which no structure is currently available, and indirect biochemical evidence suggests that it also belongs to the GT-B structural superfamily. Crystals of recombinant GumK from X. campestris have been grown that diffract to 1.9 Å resolution. Knowledge of the crystal structure of GumK will help in understanding xanthan biosynthesis and its regulation and will also allow a subsequent rational approach to enzyme design and engineering. The multiwavelength anomalous diffraction approach will be used to solve the phase problem.

  16. Improvement of in vitro embryo maturation, plantlet regeneration and transformation efficiency from alfalfa (Medicago sativa L.) somatic embryos using Cuscuta campestris extract.

    Science.gov (United States)

    Amini, Massoume; Deljou, Ali; Nabiabad, Haidar Saify

    2016-07-01

    Developmental deficiency of somatic embryos and regeneration to plantlets, especially in the case of transformation, are major problems of somatic embryo regeneration in alfalfa. One of the ways to overcome these problems is the use of natural plant regulators and nutrients in the culture medium of somatic embryos. For investigating the influence of Cuscuta campestris extract on the efficiency of plant regeneration and transformation, chimeric tissue type plasminogen activator was transferred to explants using Agrobacterium tumefaciens, and transgenic plants were recovered using medium supplemented with different concentration of the extract. Transgenic plants were analyzed by PCR and RT-PCR. Somatic embryos of Medicago sativa L. developed into plantlets at high frequency level (52 %) in the maturation medium supplemented with 50 mg 1-1C. campestris extract as compared to the medium without extract (26 %). Transformation efficiency was 29.3 and 15.2 % for medium supplemented with dodder extract and without the extract, respectively. HPLC and GC/MS analysis of the extract indicated high level of ABA and some compounds such as Phytol, which can affect the somatic embryo maturation. The antibacterial assay showed that the extract was effective against some strains of A. tumefaciens. These results have provided a scientific basis for using of C. campestris extract as a good natural source of antimicrobial agents and plant growth regulator as well, that can be used in tissue culture of transgenic plants.

  17. Resistance of cotton towards Xanthomonas campestris pv. malvacearum.

    Science.gov (United States)

    Delannoy, E; Lyon, B R; Marmey, P; Jalloul, A; Daniel, J F; Montillet, J L; Essenberg, M; Nicole, M

    2005-01-01

    Interactions between Gossypium spp. and the bacterial pathogen Xanthomonas campestris pv. malvacearum are understood in the context of the gene-for-gene concept. Reviewed here are the genetic basis for cotton resistance, with reference to resistance genes, resistance gene analogs, and bacterial avirulence genes, together with the physiological mechanisms involved in the hypersensitive response to the pathogen, including production of signaling hormones, synthesis of antimicrobial molecules and alteration of host cell structures. This host-pathogen interaction represents the most complex resistance gene/avr gene system yet known and is one of the few in which phytoalexins are known to be specifically localized in HR cells at anti-microbial concentrations.

  18. A proteomic analysis of seed development in Brassica campestri L.

    Directory of Open Access Journals (Sweden)

    Wenlan Li

    Full Text Available To gain insights into the protein dynamics during seed development, a proteomic study on the developing Brassica campestri L. seeds with embryos in different embryogenesis stages was carried out. The seed proteins at 10, 16, 20, 25 and 35 DAP (days after pollination, respectively, were separated using two-dimensional gel electrophoresis and identities of 209 spots with altered abundance were determined by matrix-assisted laser desorption ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS. These proteins were classified into 16 groups according to their functions. The most abundant proteins were related to primary metabolism, indicating the heavy demand of materials for rapid embryo growth. Besides, the high amount of proteins involved in protein processing and destination indicated importance of protein renewal during seed development. The remaining were those participated in oxidation/detoxification, energy, defense, transcription, protein synthesis, transporter, cell structure, signal transduction, secondary metabolism, transposition, DNA repair, storage and so on. Protein abundance profiles of each functional class were generated and hierarchical cluster analysis established 8 groups of dynamic patterns. Our results revealed novel characters of protein dynamics in seed development in Brassica campestri L. and provided valuable information about the complex process of seed development in plants.

  19. Detection of Xanthomonas campestris pv. citri by the polymerase chain reaction method

    OpenAIRE

    Hartung, J S; J.F. Daniel; Pruvost, O.P.

    1993-01-01

    pFL1 is a pUC9 derivative that contains a 572-bp EcoRI insert cloned from plasmid DNA of Xanthomonas campestris pv. citri XC62. The nucleotide sequence of pFL1 was determined, and the sequence information was used to design primers for application of the polymerase chain reaction (PCR) to the detection of X. campestris pv. citri, the causal agent of citrus bacterial canker disease. Seven 18-bp oligonucleotide primers were designed and tested with DNA from X. campestris pv. citri strains and o...

  20. Identification of a novel type III secretion-associated outer membrane-bound protein from Xanthomonas campestris pv. campestris.

    Science.gov (United States)

    Li, Lei; Li, Rui-Fang; Ming, Zhen-Hua; Lu, Guang-Tao; Tang, Ji-Liang

    2017-02-15

    Many bacterial pathogens employ the type III secretion system (T3SS) to translocate effector proteins into eukaryotic cells to overcome host defenses. To date, most of our knowledge about the T3SS molecular architecture comes from the studies on animal pathogens. In plant pathogens, nine Hrc proteins are believed to be structural components of the T3SS, of which HrcC and HrcJ form the outer and inner rings of the T3SS, respectively. Here, we demonstrated that a novel outer membrane-bound protein (HpaM) of Xanthomonas campestris pv. campestris is critical for the type III secretion and is structurally and functionally conserved in phytopathogenic Xanthomonas spp. We showed that the C-terminus of HpaM extends into the periplasm to interact physically with HrcJ and the middle part of HpaM interacts physically with HrcC. It is clear that the outer and inner rings compose the main basal body of the T3SS apparatus in animal pathogens. Therefore, we presume that HpaM may act as a T3SS structural component, or play a role in assisting assembling or affecting the stability of the T3SS apparatus. HpaM is a highly prevalent and specific protein in Xanthomonas spp., suggesting that the T3SS of Xanthomonas is distinctive in some aspects from other pathogens.

  1. Meio semi-seletivo para isolamento de Xanthomonas campestris pv. viticola

    Directory of Open Access Journals (Sweden)

    Peixoto Ana Rosa

    2006-01-01

    Full Text Available O cancro bacteriano causado por Xanthomonas campestris pv. viticola é a fitobacteriose mais importante da videira no Submédio São Francisco. O isolamento de X. campestris pv. viticola de tecidos vegetais infectados é dificultado pela presença de contaminantes bacterianos, entre os quais Microbacterium barkeri. Objetivando-se a formulação de meio de cultura semi-seletivo, 22 isolados de X. campestris pv. viticola foram testados com relação a 30 antibióticos. O meio semi-seletivo NYDAM (extrato de carne 3, peptona 5, glicose 10, extrato de levedura 5, ágar 18 e ampicilina 0,1 em g L-1 inibiu M. barkeri e bactérias fitopatogênicas podendo ser utilizado para isolar X. campestris pv. viticola de hospedeiros com infecção natural em campo.

  2. Detection of Xanthomonas campestris pv. citri by the polymerase chain reaction method.

    Science.gov (United States)

    Hartung, J S; Daniel, J F; Pruvost, O P

    1993-04-01

    pFL1 is a pUC9 derivative that contains a 572-bp EcoRI insert cloned from plasmid DNA of Xanthomonas campestris pv. citri XC62. The nucleotide sequence of pFL1 was determined, and the sequence information was used to design primers for application of the polymerase chain reaction (PCR) to the detection of X. campestris pv. citri, the causal agent of citrus bacterial canker disease. Seven 18-bp oligonucleotide primers were designed and tested with DNA from X. campestris pv. citri strains and other strains of X. campestris associated with Citrus spp. as templates in the PCR. Four primer pairs directed the amplification of target DNA from X. campestris pv. citri strains but not from strains of X. campestris associated with a different disease, citrus bacterial spot. Primer pair 2-3 directed the specific amplification of target DNA from pathotype A but not other pathotypes of X. campestris pv. citri. A pH 9.0 buffer that contained 1% Triton X-100 and 0.1% gelatin was absolutely required for the successful amplification of the target DNA, which was 61% G+C. Limits of detection after amplification and gel electrophoresis were 25 pg of purified target DNA and about 10 cells when Southern blots were made after gel electrophoresis and probed with biotinylated pFL1. This level of detection represents an increase in sensitivity of about 100-fold over that of dot blotting with the same hybridization probe. PCR products of the expected sizes were amplified from DNA extracted from 7-month-old lesions from which viable bacteria could not be isolated. These products were confirmed to be specific for X. campestris pv. citri by Southern blotting. This PCR-based detection protocol will be a useful addition to current methods of detection of this pathogen, which is currently the target of international quarantine measures.

  3. Antagonism of yeasts to Xanthomonas campestris pv. campestris on cabbage phylloplane in field Antagonismo de leveduras a Xanthomonas campestris pv. campestris no filoplano de repolho em condições de campo

    Directory of Open Access Journals (Sweden)

    Sayonara M.P. Assis

    1999-07-01

    Full Text Available Twenty yeast isolates, obtained from cabbage phylloplane, were evaluated for antagonistic activity against Xanthomonas campestris pv. campestris, in field. Plants of cabbage cv. Midori were pulverized simultaneously with suspensions of antagonists and pathogen. After 10 days, plants were evaluated through percentage of foliar area with lesions. Percentage of disease severity reduction (DSR% was also calculated. Yeast isolates LR32, LR42 and LR19 showed, respectively, 72, 75 and 79% of DSR. These antagonists were tested in seven different application periods in relation to pathogen inoculation (T1=4 d before; T2=simultaneously; T3=4 d after; T4=4 d before + simultaneously; T5=4 d after + simultaneously; T6=4 d before + 4 d after; T7=4 d before + simultaneously + 4 d after. The highest DSRs were showed by LR42 (71%, LR42 (67%, LR35 (69% and LR19 (68% in the treatments T7, T4, T5 and T6, which significantly differed from the others. The same yeast antagonists were also tested for black rot control using different cabbage cultivars (Fuyutoyo, Master-325, Matsukaze, Midori, Sekai I and Red Winner. The DSRs varied from 58 to 61%, and there was no significant difference among cultivars.Vinte isolados de leveduras, obtidos a partir do filoplano de repolho foram avaliados pela atividade antagônica contra Xanthomonas campestris pv. campestris, em condições de campo. Plantas de repolho cv. Midori foram pulverizadas simultaneamente com suspensões do antagonista e do patógeno. Após 10 dias, as plantas foram avaliadas através da porcentagem de área foliar infectada. A porcentagem de redução da severidade da doença (DSR%, também foi calculada. Os isolados de leveduras LR32, LR42 e LR19 apresentaram, respectivamente, 72, 75 e 79% de DSR. Estes isolados foram testados em sete diferentes períodos de aplicação dos antagonistas em relação a inoculação do patógeno. (T1=4d antes; T2=simultaneamente; T3=4 d após; T4=4 d antes + simultaneamente; T5

  4. Tranformasi Fragmen Dna Kromosom Xanthomonas Campestris ke dalam Escherichia Coli

    Directory of Open Access Journals (Sweden)

    Wibowo Mangunwardoyo

    2002-04-01

    Full Text Available Research on DNA transformation of Xanthomonas campestris into Escherichia coli DH5αα using plasmid vector Escherichia coli (pUC19. was carried out. DNA chromosome was isolated using CTAB method, alkali lysis method was used to isolate DNA plasmid. Both of DNA plasmid and chromosome were digested using restriction enzyme EcoRI. Competent cell was prepared with CaCl2 and heat shock method for transformation procedure. The result revealed transformation obtain 5 white colonies, with transformation frequency was 1,22 x 10-8 colony/competent cell. Electrophoresis analysis showed the DNA fragment (insert in range 0.5 – 7,5 kb. Further research should be carried out to prepare the genomic library to obtain better result of transformant.

  5. Role of Glycolytic Intermediates in Global Regulation and Signal Transduction. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Liao, J.C.

    2000-05-08

    The goal of this project is to determine the role of glycolytic intermediates in regulation of cell physiology. It is known that many glycolytic intermediates are involved in regulation of enzyme activities at the kinetic level. However, little is known regarding the role of these metabolites in global regulation and signal transduction. This project aims to investigate the role of glycolytic intermediates in the regulation of gene expression.

  6. Regulate Globally, Act Locally: Adrenergic Nerves Promote Leukocyte Recruitment

    OpenAIRE

    Muller, William A.

    2012-01-01

    In this issue of Immunity, Scheiermann et al. (2012) demonstrate that circadian regulation of the expression of endothelial cell adhesion molecules via adrenergic innervation of local vasculature promotes clinically significant changes in leukocyte homing and bone marrow engraftment.

  7. Biosynthesis of Zinc Oxide Nano-rods Using Xanthomonas campestris

    Directory of Open Access Journals (Sweden)

    Zahra sadat Mahdi

    2017-06-01

    Full Text Available Introduction: one dimensional nanocrystals especially nano-rods have attracted a great deal of attention due to their unique properties and wide applications in industry. Chemical and physical methods which are currently used to produce zinc oxide nano- rods, often leave toxic chemicals on surface of nanoparticles limiting their applications for health and medical purposes. Therefore, biological synthesis of zinc oxide nanoparticles has been considered as an environmentally friendly process and a potential alternative to chemical and physical methods. Materials and methods: Nano-rods of zinc oxide were produced by Xanthomonas campestris using zinc nitrate hexa hydrate as substrate, in a shaker incubator at 37 ° C and pH 7. The powder produced was then calcined at 600 ° C for 2 hours after drying. The synthesized ZnO nanoparticles were characterized using FTIR, XRD, SEM, EDX and UV–vis spectroscopy. Results: FTIR analysis was used to identify functional groups involved in the biosynthesis of ZnO NPs. The peak observed at 563 cm-1 corresponds to the stretching vibrations of ZnO NPs. XRD analysis revealed that the hexagonal ZnO nanoparticles synthesized were pure and crystalline in nature. The morphology and size of the powder were investigated using SEM analysis and the results showed that ZnO nano-rods have a diameter ranging from 122–200 nm with an average length about 300 nm. EDX analysis was performed for determination of the elemental composition and purity of samples. The recorded EDX spectrum revealed the high purity of the synthesized ZnO nano-rods without detection of any impurities. The absorption peak at 376 nm indicating the presence of zinc oxide nanoparticles was further confirmed by UV-Vis spectroscopy. Discussion and conclusion: The current research work describes a low-cost, unreported, nontoxic, simple, safe and eco-friendly method for the biosynthesis of zinc oxide nanoparticle using xanthomonas campestris as the reducing

  8. Avaliação de meios semi-seletivos e técnicas moleculares para detecção de Xanthomonas campestris pv. campestris

    OpenAIRE

    Amaral, Lívio da Silva

    2012-01-01

    Avaliou-se a eficiência de meios de cultura semi-seletivos, de testes de patogenicidade e a especificidade de primers para a detecção de Xanthomonas campestris pv. campestris (Xcc). Para a execução dos experimentos, foram utilizados 29 isolados recebidos de diferentes regiões do Brasil. Para a confirmação da identidade dos isolados foram realizados os testes de produção de xantomonadinas e de utilização de asparagina, análise da região 16s do genoma bacteriano e testes de patogenicidade. Dos ...

  9. Xanthomonas campestris pv. vesicatoria Secretes Proteases and Xylanases via the Xps Type II Secretion System and Outer Membrane Vesicles

    Science.gov (United States)

    Solé, Magali; Scheibner, Felix; Hoffmeister, Anne-Katrin; Hartmann, Nadine; Hause, Gerd; Rother, Annekatrin; Jordan, Michael; Lautier, Martine; Arlat, Matthieu

    2015-01-01

    ABSTRACT Many plant-pathogenic bacteria utilize type II secretion (T2S) systems to secrete degradative enzymes into the extracellular milieu. T2S substrates presumably mediate the degradation of plant cell wall components during the host-pathogen interaction and thus promote bacterial virulence. Previously, the Xps-T2S system from Xanthomonas campestris pv. vesicatoria was shown to contribute to extracellular protease activity and the secretion of a virulence-associated xylanase. The identities and functions of additional T2S substrates from X. campestris pv. vesicatoria, however, are still unknown. In the present study, the analysis of 25 candidate proteins from X. campestris pv. vesicatoria led to the identification of two type II secreted predicted xylanases, a putative protease and a lipase which was previously identified as a virulence factor of X. campestris pv. vesicatoria. Studies with mutant strains revealed that the identified xylanases and the protease contribute to virulence and in planta growth of X. campestris pv. vesicatoria. When analyzed in the related pathogen X. campestris pv. campestris, several T2S substrates from X. campestris pv. vesicatoria were secreted independently of the T2S systems, presumably because of differences in the T2S substrate specificities of the two pathogens. Furthermore, in X. campestris pv. vesicatoria T2S mutants, secretion of T2S substrates was not completely absent, suggesting the contribution of additional transport systems to protein secretion. In line with this hypothesis, T2S substrates were detected in outer membrane vesicles, which were frequently observed for X. campestris pv. vesicatoria. We, therefore, propose that extracellular virulence-associated enzymes from X. campestris pv. vesicatoria are targeted to the Xps-T2S system and to outer membrane vesicles. IMPORTANCE The virulence of plant-pathogenic bacteria often depends on TS2 systems, which secrete degradative enzymes into the extracellular milieu. T2S

  10. Antioxidant, antibacterial, anti-inflammatory and wound healing effects of Artemisia campestris aqueous extract in rat.

    Science.gov (United States)

    Ghlissi, Zohra; Sayari, Nadhim; Kallel, Rim; Bougatef, Ali; Sahnoun, Zouheir

    2016-12-01

    This study investigated some biological properties of Artemisia campestris aqueous extract (ACAE) as well its global chemical compositions. Twenty four rats were excised on the posterior neck skin area and divided into 4 groups, treated respectively with: sterile saline, glycerol, CICAFLORA and ACAE. The wound closure rate, histopathology evolution and the superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) level in skin tissue were evaluated. Anti-inflammatory activity was studied by carrageenan-induced rat paw edema. Animals were divided into 3 groups pre-treated respectively with sterile saline, acetylsalicylic acid (AA) and ACAE. The antibacterial activity was tested against six bacteria and the antioxidant activity was estimated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power and β-carotene activities. Our results demonstrated a significant improvement in wound healing progression and in oxidative stress damage in the wounds tissues of ACAE-treated rats, compared to control. ACAE-treated rats revealed also a significant inhibition of carrageenan-induced hind paws edema as confirmed by the histological analysis. In addition to the antioxidant activity, ACAE showed considerable antibacterial activities. ACAE exhibited important wound healing effect probably due to the anti-inflammatory, antibacterial and antioxidant activities of its phytochemical contents. Therefore, this study confirms its popular use and highlights its promise in the development of new drugs. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Regulation of water resources for sustaining global future socioeconomic development

    Science.gov (United States)

    Chen, J.; SHI, H.; Sivakumar, B.

    2016-12-01

    With population projections indicating continued growth during this century, socio-economic problems (e.g., water, food, and energy shortages) will be most likely to occur, especially if proper planning, development, and management strategies are not adopted. In the present study, firstly, we explore the vital role of dams in promoting economic growth through analyzing the relationship between dams and Gross Domestic Product (GDP) at both global and national scales. Secondly, we analyze the current situation of global water scarcity based on the data representing water resources availability, dam development, and the level of economic development. Third, with comprehensive consideration of population growth as the major driving force, water resources availability as the basic supporting factor, and topography as the important constraint, this study addresses the question of dam development in the future and predicts the locations of future dams around the world.

  12. Evolution of Enzymatic Activities in the Enolase Superfamily: L-Fuconate Dehydratase from Xanthomonas campestris

    Energy Technology Data Exchange (ETDEWEB)

    Yew,W.; Fedorov, A.; Fedorov, E.; Rakus, J.; Pierce, R.; Almo, S.; Gerlt, J.

    2006-01-01

    Many members of the mechanistically diverse enolase superfamily have unknown functions. In this report the authors use both genome (operon) context and screening of a library of acid sugars to assign the L-fuconate dehydratase (FucD) function to a member of the mandelate racemase (MR) subgroup of the superfamily encoded by the Xanthomonas campestris pv. campestris str. ATCC 33913 genome (GI: 21233491). Orthologues of FucD are found in both bacteria and eukaryotes, the latter including the rTS beta protein in Homo sapiens that has been implicated in regulating thymidylate synthase activity. As suggested by sequence alignments and confirmed by high-resolution structures in the presence of active site ligands, FucD and MR share the same active site motif of functional groups: three carboxylate ligands for the essential Mg2+ located at the ends of th third, fourth, and fifth-strands in the (/)7-barrel domain (Asp 248, Glu 274, and Glu 301, respectively), a Lys-x-Lys motif at the end of the second-strand (Lys 218 and Lys 220), a His-Asp dyad at the end of the seventh and sixth-strands (His 351 and Asp 324, respectively), and a Glue at the end of the eighth-strand (Glu 382). The mechanism of the FucD reaction involves initial abstraction of the 2-proton by Lys 220, acid catalysis of the vinylogous-elimination of the 3-OH group by His 351, and stereospecific ketonization of the resulting 2-keto-3-deoxy-L-fuconate product. Screening of the library of acid sugars revealed substrate and functional promiscuity: In addition to L-fuconate, FucD also catalyzes the dehydration of L-galactonate, D-arabinonate, D-altronate, L-talonate, and D-ribonate. The dehydrations of L-fuconate, L-galactonate, and D-arabinonate are initiated by abstraction of the 2-protons by Lys 220. The dehydrations of L-talonate and D-ribonate are initiated by abstraction of the 2-protons by His 351; however, protonation of the enediolate intermediates by the conjugate acid of Lys 220 yields L

  13. Internet governance and global self regulation: theoretical and empirical building blocks for a general theory of self regulation

    NARCIS (Netherlands)

    Vey Mestdagh, C.; Rijgersberg, R.

    2010-01-01

    The following exposition sets out to identify the basic theoretical and empirical building blocks for a general theory of self-regulation. It uses the Internet as an empirical basis since its global reach and technical characteristics create interdependencies between actors that transcend national

  14. Global regulation by CsrA in Salmonella typhimurium.

    Science.gov (United States)

    Lawhon, Sara D; Frye, Jonathan G; Suyemoto, Mitsu; Porwollik, Steffen; McClelland, Michael; Altier, Craig

    2003-06-01

    CsrA is a regulator of invasion genes in Salmonella enterica serovar Typhimurium. To investigate the wider role of CsrA in gene regulation, we compared the expression of Salmonella genes in a csrA mutant with those in the wild type using a DNA microarray. As expected, we found that expression of Salmonella pathogenicity island 1 (SPI-1) invasion genes was greatly reduced in the csrA mutant, as were genes outside the island that encode proteins translocated into eukaryotic cells by the SPI-1 type III secretion apparatus. The flagellar synthesis operons, flg and fli, were also poorly expressed, and the csrA mutant was aflagellate and non-motile. The genes of two metabolic pathways likely to be used by Salmonella in the intestinal milieu also showed reduced expression: the pdu operon for utilization of 1,2-propanediol and the eut operon for ethanolamine catabolism. Reduced expression of reporter fusions in these two operons confirmed the microarray data. Moreover, csrA was found to regulate co-ordinately the cob operon for synthesis of vitamin B12, required for the metabolism of either 1,2-propanediol or ethanolamine. Additionally, the csrA mutant poorly expressed the genes of the mal operon, required for transport and use of maltose and maltodextrins, and had reduced amounts of maltoporin, normally a dominant protein of the outer membrane. These results show that csrA controls a number of gene classes in addition to those required for invasion, some of them unique to Salmonella, and suggests a co-ordinated bacterial response to conditions that exist at the site of bacterial invasion, the intestinal tract of a host animal.

  15. Local flow regulation and irrigation raise global human water consumption and footprint.

    Science.gov (United States)

    Jaramillo, Fernando; Destouni, Georgia

    2015-12-04

    Flow regulation and irrigation alter local freshwater conditions, but their global effects are highly uncertain. We investigated these global effects from 1901 to 2008, using hydroclimatic observations in 100 large hydrological basins. Globally, we find consistent and dominant effects of increasing relative evapotranspiration from both activities, and decreasing temporal runoff variability from flow regulation. The evapotranspiration effect increases the long-term average human consumption of fresh water by 3563 ± 979 km(3)/year from 1901-1954 to 1955-2008. This increase raises a recent estimate of the current global water footprint of humanity by around 18%, to 10,688 ± 979 km(3)/year. The results highlight the global impact of local water-use activities and call for their relevant account in Earth system modeling. Copyright © 2015, American Association for the Advancement of Science.

  16. Proteomics Reveals Global Regulation of Protein SUMOylation by ATM and ATR Kinases during Replication Stress

    Directory of Open Access Journals (Sweden)

    Stephanie Munk

    2017-10-01

    Full Text Available The mechanisms that protect eukaryotic DNA during the cumbersome task of replication depend on the precise coordination of several post-translational modification (PTM-based signaling networks. Phosphorylation is a well-known regulator of the replication stress response, and recently an essential role for SUMOs (small ubiquitin-like modifiers has also been established. Here, we investigate the global interplay between phosphorylation and SUMOylation in response to replication stress. Using SUMO and phosphoproteomic technologies, we identify thousands of regulated modification sites. We find co-regulation of central DNA damage and replication stress responders, of which the ATR-activating factor TOPBP1 is the most highly regulated. Using pharmacological inhibition of the DNA damage response kinases ATR and ATM, we find that these factors regulate global protein SUMOylation in the protein networks that protect DNA upon replication stress and fork breakage, pointing to integration between phosphorylation and SUMOylation in the cellular systems that protect DNA integrity.

  17. Cap0037, a Novel Global Regulator of Clostridium acetobutylicum Metabolism

    Directory of Open Access Journals (Sweden)

    Ngoc-Phuong-Thao Nguyen

    2016-10-01

    Full Text Available An operon comprising two genes, CA_P0037 and CA_P0036, that encode proteins of unknown function that were previously shown to be highly expressed in acidogenic cells and repressed in solventogenic and alcohologenic cells is located on the pSOL1 megaplasmid of Clostridium acetobutylicum upstream of adhE2. A CA_P0037::int (189/190s mutant in which an intron was inserted at position 189/190 in the sense strand of CA_P0037 was successfully generated by the Targetron technique. The resultant mutant showed significantly different metabolic flux patterns in acidogenic (producing mainly lactate, butyrate, and butanol and alcohologenic (producing mainly butyrate, acetate, and lactate chemostat cultures but not in solventogenic or batch cultures. Transcriptomic investigation of the CA_P0037::int (189/190s mutant showed that inactivation of CA_P0037 significantly affected the expression of more than 258 genes under acidogenic conditions. Surprisingly, genes belonging to the Fur regulon, involved in iron transport (CA_C1029-CA_C1032, or coding for the main flavodoxin (CA_C0587 were the most significantly expressed genes under all conditions, whereas fur (coding for the ferric uptake regulator gene expression remained unchanged. Furthermore, most of the genes of the Rex regulon, such as the adhE2 and ldhA genes, and of the PerR regulon, such as rbr3A-rbr3B and dfx, were overexpressed in the mutant. In addition, the whole CA_P0037-CA_P0036 operon was highly expressed under all conditions in the CA_P0037::int (189/190s mutant, suggesting a self-regulated expression mechanism. Cap0037 was shown to bind to the CA_P0037-CA_P0036 operon, sol operon, and adc promoters, and the binding sites were determined by DNA footprinting. Finally, a putative Cap0037 regulon was generated using a bioinformatic approach.

  18. The cloning, crystallization and preliminary X-ray analysis of XC2113, a YaeQ protein from Xanthomonas campestris

    Energy Technology Data Exchange (ETDEWEB)

    Chio, Kuo-Cheng; Chin, Ko-Hsin [Institute of Biochemistry, National Chung-Hsing University, Taichung 40227,Taiwan (China); Gao, Fei Philip [Florida State University, Tallahassee, FL 32310 (United States); Lyu, Ping-Chiang [Department of Life Science, National Tsing Hua University, Hsin-Chu,Taiwan (China); Shr, Hui-Lin; Wang, Andrew H.-J. [Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei,Taiwan (China); Core Facility for Protein Crystallography, Academia Sinica, Nankang, Taipei,Taiwan (China); Chou, Shan-Ho, E-mail: shchou@nchu.edu.tw [Institute of Biochemistry, National Chung-Hsing University, Taichung 40227,Taiwan (China)

    2006-10-01

    A YaeQ protein from the plant pathogen X. campestris pv. campestris has been overexpressed in E. coli, purified and crystallized. The crystals diffracted well to a resolution of 1.28 Å. Xanthomonas campestris is a Gram-negative bacterium that is phytopathogenic to cruciferous plants and causes worldwide agricultural loss. It is therefore important to identify potential pathogenic factors involved in this plant disease. Here, the cloning, expression, crystallization and preliminary X-ray analysis of XC2113, a YaeQ protein possibly involved in the production of virulence factors in Xanthomonas campestris pathovar campestris, are reported. The XC2113 crystals diffracted well to a resolution of at least 1.28 Å. They are orthorhombic and belong to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 32.86, b = 62.69, c = 79.96 Å.

  19. Modelling Xanthomonas campestris batch fermentations in a bubble column.

    Science.gov (United States)

    Pons, A; Dussap, C G; Gros, J B

    1989-01-20

    Rate and yield expressions relating to biomass and xanthan formation and to nitrogen, glucose, and oxygen consumption were established for Xanthomonas campestris batch fermentations in a bubble column. Microbial growth was described by the logistic rate equation, characterized by a maximum specific growth rate mu(M) = 0.5 h(-1) and a maximum attainable cell concentration provided by nitrogenous compounds. With regard to carbon metabolism, the decrease with time in experimental yields and in the experimental specific rates of xanthan production and glucose assimilation demonstrated the inadequacy of the Luedeking-Piret model. These decreases were connected to the simultaneous drop in dissolved-oxygen tension observed during xanthan synthesis. The knowledge of metabolic pathways and energetic balance were used to establish the relationships between substrate utilization, ATP generation, and xanthan production. The model was structured by assuming the oxygen limitation of both the respiration rate and the efficiency of the oxidative phosphorylation mechanism (P/O ratio). Consequently, the specific rates and yield expressions became dependent on the dissolved-oxygen tension, i.e., of the volumetric oxygen transfer in the fermentor.

  20. Production and cytogenetics of Brassica campestris-alboglabra chromosome addition lines

    DEFF Research Database (Denmark)

    Chen, B.Y.; Cheng, B.F.; Bagger Jørgensen, Rikke

    1997-01-01

    Four different Brassica campestris-alboglabra monosomic addition lines (AA + 1 chromosome from C, 2n = 21) were obtained after consecutive backcrosses between resynthesized B. napus (AACC, 2n = 38) and the parental B. campestris (AA, 2n = 20) accession. The alien chromosomes of B. alboglabra (CC, 2......n = 18) in the addition lines were distinguished by random amplified polymorphic DNA (RAPD) marker analysis and morphology of mitotic chromosomes. Four RAPD marker synteny groups were established, which represented the four different alien chromosomes of B. alboglabra in the four addition lines...

  1. DNA probes for detection of copper resistance genes in Xanthomonas campestris pv. Vesicatoria

    Energy Technology Data Exchange (ETDEWEB)

    Garde, S.; Bender, C.L. (Oklahoma State Univ., Stillwater (USA))

    1991-08-01

    The copper resistance (Cu{sup r}) genes encoded on pXV10A, a 190-kb plasmid in Xanthomonas campestris pv. vesicatoria XV10, were isolated on a 44-kb cosmid clone designated pCuR1. Tn5 mutagenesis of pCuR1 indicated that a 4.0-kb region was required for copper resistance. Three restriction fragments located within the 4.0-kb region demonstrated high specificity for the Cu{sup r} genes present in X. campestris pv. vesicatoria and will be useful in monitoring the presence of these genes in the environment.

  2. Detecção, transmissão e efeito de Xanthomonas campestris pv. campestris na qualidade fisiológica de sementes de brócolis Detection, transmission and effect of Xanthomonas campestris pv. campestris in the physiological quality of broccoli seeds

    OpenAIRE

    Nilvanira Donizete Tebaldi; Rita de Cássia Panizzi; Rubens Sader

    2007-01-01

    A detecção, a transmissão e o efeito de Xanthomonas campestris pv. campestris (Xcc) na qualidade fisiológica de sementes de brócolis (Brassica oleracea var. italica) foram avaliadas, a partir de sementes obtidas de plantas ("Baron, Flórida, Hana Midori Sakata, Precoce Piracicaba de Verão, Ramoso Santana e Sabre") inoculadas com a bactéria, em condições de campo. Para a detecção do patógeno nas sementes foram utilizados os meios de cultura semi-seletivos: SX ágar, NSCAA e BSCAA; a taxa de tran...

  3. DNA probes for detection of copper resistance genes in Xanthomonas campestris pv. vesicatoria.

    OpenAIRE

    Garde, S; Bender, C L

    1991-01-01

    The copper resistance (Cur) genes encoded on pXV10A, a 190-kb plasmid in Xanthomonas campestris pv. vesicatoria XV10, were isolated on a 44-kb cosmid clone designated pCuR1. Tn5 mutagenesis of pCuR1 indicated that a 4.0-kb region was required for copper resistance. Three restriction fragments located within the 4.0-kb region demonstrated high specificity for the Cur genes present in X. campestris pv. vesicatoria and will be useful in monitoring the presence of these genes in the environment.

  4. DNA probes for detection of copper resistance genes in Xanthomonas campestris pv. vesicatoria.

    Science.gov (United States)

    Garde, S; Bender, C L

    1991-08-01

    The copper resistance (Cur) genes encoded on pXV10A, a 190-kb plasmid in Xanthomonas campestris pv. vesicatoria XV10, were isolated on a 44-kb cosmid clone designated pCuR1. Tn5 mutagenesis of pCuR1 indicated that a 4.0-kb region was required for copper resistance. Three restriction fragments located within the 4.0-kb region demonstrated high specificity for the Cur genes present in X. campestris pv. vesicatoria and will be useful in monitoring the presence of these genes in the environment.

  5. Proteomics Reveals Global Regulation of Protein SUMOylation by ATM and ATR Kinases during Replication Stress

    DEFF Research Database (Denmark)

    Munk, Stephanie; Sigurðsson, Jón Otti; Xiao, Zhenyu

    2017-01-01

    The mechanisms that protect eukaryotic DNA during the cumbersome task of replication depend on the precise coordination of several post-translational modification (PTM)-based signaling networks. Phosphorylation is a well-known regulator of the replication stress response, and recently an essentia....... They analyze changes in the SUMO and phosphoproteome after MMC and hydroxyurea treatments and find that the DNA damage response kinases ATR and ATM globally regulate SUMOylation upon replication stress and fork breakage....

  6. Building Responsive and Responsible Financial Regulators in the Aftermath of the Global Financial Crisis

    NARCIS (Netherlands)

    Iglesias Rodriguez, P.

    2015-01-01

    The global financial crisis that started in 2007 sparked several academic debates about the role that financial sector regulators played in the crisis and prompted policy reforms in the financial supervision architectures of several countries. This book focuses on the question of what

  7. Quantitative analysis of proteome and lipidome dynamics reveals functional regulation of global lipid metabolism

    DEFF Research Database (Denmark)

    Casanovas, Albert; Sprenger, Richard R; Tarasov, Kirill

    2015-01-01

    Elucidating how and to what extent lipid metabolism is remodeled under changing conditions is essential for understanding cellular physiology. Here, we analyzed proteome and lipidome dynamics to investigate how regulation of lipid metabolism at the global scale supports remodeling of cellular...

  8. Insights into the global regulation of anaerobic metabolism for improved biohydrogen production.

    Science.gov (United States)

    Lu, Yuan; Zhao, Hongxin; Zhang, Chong; Xing, Xin-Hui

    2016-01-01

    To improve the biohydrogen yield in bacterial dark fermentation, a new approach of global anaerobic regulation was introduced. Two cellular global regulators FNR and NarP were overexpressed in two model organisms: facultatively anaerobic Enterobacter aerogenes (Ea) and strictly anaerobic Clostridium paraputrificum (Cp). The overexpression of FNR and NarP greatly altered anaerobic metabolism and increased the hydrogen yield by 40%. Metabolic analysis showed that the global regulation caused more reducing environment inside the cell. To get a thorough understanding of the global metabolic regulation, more genes (fdhF, fhlA, ppk, Cb-fdh1, and Sc-fdh1) were overexpressed in different Ea and Cp mutants. For the first time, it demonstrated that there were approximately linear relationships between the relative change of hydrogen yield and the relative change of NADH yield or ATP yield. It implied that cellular reducing power and energy level played vital roles in the biohydrogen production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Predation of Indianmeal moth larvae by Lyctocoris campestris(F.) (Hemiptera: Anthocoridae) in different stored commodities

    Science.gov (United States)

    Predation rates for the anthocorid predator Lyctocoris campestris (F.) against varying densities of late-instar Plodia interpunctello (Hubner) were compared in whole corn, whole wheat, or folled oat stored commodities. More prey were attacked in corn and wheat than in oats, and female predators gene...

  10. Host Genotype and Hypersensitive Reaction Influence Population Levels of Xanthomonas campestris pv. vitians in Lettuce.

    Science.gov (United States)

    Bull, Carolee T; Gebben, Samantha J; Goldman, Polly H; Trent, Mark; Hayes, Ryan J

    2015-03-01

    Dynamics of population sizes of Xanthomonas campestris pv. vitians inoculated onto or into lettuce leaves were monitored on susceptible and resistant cultivars. In general, population growth was greater for susceptible (Clemente, Salinas 88, Vista Verde) than resistant (Batavia Reine des Glaces, Iceberg, Little Gem) cultivars. When spray-inoculated or infiltrated, population levels of X. campestris pv. vitians were consistently significantly lower on Little Gem than on susceptible cultivars, while differences in the other resistant cultivars were not consistently statistically significant. Populations increased at an intermediate rate on cultivars Iceberg and Batavia Reine des Glaces. There were significant positive correlations between bacterial concentration applied and disease severity for all cultivars, but bacterial titer had a significantly greater influence on disease severity in the susceptible cultivars than in Little Gem and an intermediate influence in Iceberg and Batavia Reine des Glaces. Infiltration of X. campestris pv. vitians strains into leaves of Little Gem resulted in an incompatible reaction, whereas compatible reactions were observed in all other cultivars. It appears that the differences in the relationship between population dynamics for Little Gem and the other cultivars tested were due to the hypersensitive response in cultivar Little Gem. These findings have implications for disease management and lettuce breeding because X. campestris pv. vitians interacts differently with cultivars that differ for resistance mechanisms.

  11. Aspects of quantitative resistance to Xanthomonas campestris pv. oryzae in rice

    NARCIS (Netherlands)

    Koch, M.F.

    1990-01-01

    Quantitative resistance (QR) toXanthomonas campestris pv. oryzae (Xco), the causal organism of bacterial blight in rice, is evident as reduced lesion length and slowed lesion development relative

  12. Host genotype and hypersensitive reaction influence population levels of Xanthomonas campestris pv. vitians in lettuce

    Science.gov (United States)

    Population dynamics of Xanthomonas campestris pv. vitians spray inoculated on or infiltrated into lettuce leaves were monitored on cultivars that were well characterized for resistance or susceptibility to the pathogen. In general, population growth was greater for susceptible (Clemente, Salinas 88,...

  13. Use of bioluminescence for detection of genetically engineered microorganisms released into the environment. [Xanthomonas campestris

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J.J.; Dane, F.; Geiger, D.; Kloepper, J.W. (Auburn Univ., AL (United States))

    1992-01-01

    The persistence and movement of strain JS414 of Xanthomonas campestris pv. campestris, which was genetically engineered to bioluminesce, were monitored during a limited field introduction. Bioluminescence and traditional dilution plate counts were determined. Strain JS414 was applied to cabbage plants and surrounding soil by mist inoculation, by wound inoculation, by scattering infested debris among plants, and by incorporating bacteria into the soil. Bioluminescent X. campestris pv. campestris was detected in plant samples and in the rhizosphere up to 6 weeks after inoculation. Movement to uninoculated plants was detected on one occasion, but movement from the immediate release area was not detected. Strain JS414 was detected in soil samples beneath mist- and wound-inoculated plants only at intentionally infested locations and in aerial samples only on the day of inoculation. The authors bioluminescence methods proved to be as sensitive as plating methods for detecting the genetically engineered microorganisms in environmental samples. Their results demonstrate that transgenic incorporation of the luxCDABE operon provides a non-labor-intensive, sensitive detection method for monitoring genetically engineered microorganisms in nature.

  14. Autism and increased paternal age related changes in global levels of gene expression regulation.

    Directory of Open Access Journals (Sweden)

    Mark D Alter

    Full Text Available A causal role of mutations in multiple general transcription factors in neurodevelopmental disorders including autism suggested that alterations in global levels of gene expression regulation might also relate to disease risk in sporadic cases of autism. This premise can be tested by evaluating for changes in the overall distribution of gene expression levels. For instance, in mice, variability in hippocampal-dependent behaviors was associated with variability in the pattern of the overall distribution of gene expression levels, as assessed by variance in the distribution of gene expression levels in the hippocampus. We hypothesized that a similar change in variance might be found in children with autism. Gene expression microarrays covering greater than 47,000 unique RNA transcripts were done on RNA from peripheral blood lymphocytes (PBL of children with autism (n = 82 and controls (n = 64. Variance in the distribution of gene expression levels from each microarray was compared between groups of children. Also tested was whether a risk factor for autism, increased paternal age, was associated with variance. A decrease in the variance in the distribution of gene expression levels in PBL was associated with the diagnosis of autism and a risk factor for autism, increased paternal age. Traditional approaches to microarray analysis of gene expression suggested a possible mechanism for decreased variance in gene expression. Gene expression pathways involved in transcriptional regulation were down-regulated in the blood of children with autism and children of older fathers. Thus, results from global and gene specific approaches to studying microarray data were complimentary and supported the hypothesis that alterations at the global level of gene expression regulation are related to autism and increased paternal age. Global regulation of transcription, thus, represents a possible point of convergence for multiple etiologies of autism and other

  15. Circadian yin-yang regulation and its manipulation to globally reprogram gene expression.

    Science.gov (United States)

    Xu, Yao; Weyman, Philip D; Umetani, Miki; Xiong, Jing; Qin, Ximing; Xu, Qing; Iwasaki, Hideo; Johnson, Carl Hirschie

    2013-12-02

    The cyanobacterial circadian program exerts genome-wide control of gene expression. KaiC undergoes rhythms of phosphorylation that are regulated by interactions with KaiA and KaiB. The phosphorylation status of KaiC is thought to mediate global transcription via output factors SasA, CikA, LabA, RpaA, and RpaB. Overexpression of kaiC has been reported to globally repress gene expression. Here, we show that the positive circadian component KaiA upregulates "subjective dusk" genes and that its overexpression deactivates rhythmic gene expression without significantly affecting growth rates in constant light. We analyze the global patterns of expression that are regulated by KaiA versus KaiC and find in contrast to the previous report of KaiC repression that there is a "yin-yang" regulation of gene expression whereby kaiA overexpression activates "dusk genes" and represses "dawn genes," whereas kaiC overexpression complementarily activates dawn genes and represses dusk genes. Moreover, continuous induction of kaiA latched KaiABC-regulated gene expression to provide constitutively increased transcript levels of diverse endogenous and heterologous genes that are expressed in the predominant subjective dusk phase. In addition to analyzing KaiA regulation of endogenous gene expression, we apply these insights to the expression of heterologous proteins whose products are of potential value, namely human proinsulin, foreign luciferase, and exogenous hydrogenase. Both KaiC and KaiA complementarily contribute to the regulation of circadian gene expression via yin-yang switching. Circadian patterns can be reprogrammed by overexpression of kaiA or kaiC to constitutively enhance gene expression, and this reprogramming can improve 24/7 production of heterologous proteins that are useful as pharmaceuticals or biofuels. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Post-Transcriptional Regulation by the Csr Global Regulatory System in Escherichia coli

    OpenAIRE

    Suzuki, Kazushi; 鈴木, 一史

    2007-01-01

    In many species of bacteria, the Csr (carbon storage regulator) global regulatory system coordinates the expression of various genes. In Escherichia coli, the central component of this system, CsrA, is a RNA-binding protein. The CsrA is a homodimer and binds to leader segments of target mRNAs, affecting their translation and stability. CsrA activity is regulated by two small non-coding RNAs, CsrB and CsrC. These RNAs contain multiple CsrA-binding sequences and act by sequestering CsrA. In thi...

  17. The bacterial response regulator ArcA uses a diverse binding site architecture to regulate carbon oxidation globally.

    Directory of Open Access Journals (Sweden)

    Dan M Park

    Full Text Available Despite the importance of maintaining redox homeostasis for cellular viability, how cells control redox balance globally is poorly understood. Here we provide new mechanistic insight into how the balance between reduced and oxidized electron carriers is regulated at the level of gene expression by mapping the regulon of the response regulator ArcA from Escherichia coli, which responds to the quinone/quinol redox couple via its membrane-bound sensor kinase, ArcB. Our genome-wide analysis reveals that ArcA reprograms metabolism under anaerobic conditions such that carbon oxidation pathways that recycle redox carriers via respiration are transcriptionally repressed by ArcA. We propose that this strategy favors use of catabolic pathways that recycle redox carriers via fermentation akin to lactate production in mammalian cells. Unexpectedly, bioinformatic analysis of the sequences bound by ArcA in ChIP-seq revealed that most ArcA binding sites contain additional direct repeat elements beyond the two required for binding an ArcA dimer. DNase I footprinting assays suggest that non-canonical arrangements of cis-regulatory modules dictate both the length and concentration-sensitive occupancy of DNA sites. We propose that this plasticity in ArcA binding site architecture provides both an efficient means of encoding binding sites for ArcA, σ(70-RNAP and perhaps other transcription factors within the same narrow sequence space and an effective mechanism for global control of carbon metabolism to maintain redox homeostasis.

  18. Spaceflight Alters Bacterial Gene Expression and Virulence and Reveals Role for Global Regulator Hfq

    Science.gov (United States)

    Wilson, J. W.; Ott, C. M.; zuBentrup, K. Honer; Ramamurthy R.; Quick, L.; Porwollik, S.; Cheng, P.; McClellan, M.; Tsaprailis, G.; Radabaugh, T.; hide

    2007-01-01

    A comprehensive analysis of both the molecular genetic and phenotypic responses of any organism to the spaceflight environment has never been accomplished due to significant technological and logistical hurdles. Moreover, the effects of spaceflight on microbial pathogenicity and associated infectious disease risks have not been studied. The bacterial pathogen Salmonella typhimurium was grown aboard Space Shuttle mission STS-115 and compared to identical ground control cultures. Global microarray and proteomic analyses revealed 167 transcripts and 73 proteins changed expression with the conserved RNA-binding protein Hfq identified as a likely global regulator involved in the response to this environment. Hfq involvement was confirmed with a ground based microgravity culture model. Spaceflight samples exhibited enhanced virulence in a murine infection model and extracellular matrix accumulation consistent with a biofilm. Strategies to target Hfq and related regulators could potentially decrease infectious disease risks during spaceflight missions and provide novel therapeutic options on Earth.

  19. Revisiting the legal regulation of digital identity in the light of global implementation and local difference

    OpenAIRE

    Rodrigues, Rowena Edwardina

    2011-01-01

    This thesis aims to address a vital gap that has emerged in the digital identity regulatory discourse: how can the legal regulation of digital identity mirror the global nature of digital identity and be compatible with national local difference? Digital identity, or the digital representation of an individual, is a complex concept, which manifests in myriad forms (e.g. authenticators, claims, data or information, identifiers, presence, relationship representations and reputati...

  20. Engineering global regulator Hha of Escherichia coli to control biofilm dispersal

    OpenAIRE

    Hong, Seok Hoon; Lee, Jintae; Wood, Thomas K.

    2010-01-01

    Summary The global transcriptional regulator Hha of Escherichia coli controls biofilm formation and virulence. Previously, we showed that Hha decreases initial biofilm formation; here, we engineered Hha for two goals: to increase biofilm dispersal and to reduce biofilm formation. Using random mutagenesis, Hha variant Hha13D6 (D22V, L40R, V42I and D48A) was obtained that causes nearly complete biofilm dispersal (96%) by increasing apoptosis without affecting initial biofilm formation. Hha13D6 ...

  1. Global regulator SATB1 recruits beta-catenin and regulates T(H2 differentiation in Wnt-dependent manner.

    Directory of Open Access Journals (Sweden)

    Dimple Notani

    2010-01-01

    Full Text Available In vertebrates, the conserved Wnt signalling cascade promotes the stabilization and nuclear accumulation of beta-catenin, which then associates with the lymphoid enhancer factor/T cell factor proteins (LEF/TCFs to activate target genes. Wnt/beta -catenin signalling is essential for T cell development and differentiation. Here we show that special AT-rich binding protein 1 (SATB1, the T lineage-enriched chromatin organizer and global regulator, interacts with beta-catenin and recruits it to SATB1's genomic binding sites. Gene expression profiling revealed that the genes repressed by SATB1 are upregulated upon Wnt signalling. Competition between SATB1 and TCF affects the transcription of TCF-regulated genes upon beta-catenin signalling. GATA-3 is a T helper type 2 (T(H2 specific transcription factor that regulates production of T(H2 cytokines and functions as T(H2 lineage determinant. SATB1 positively regulated GATA-3 and siRNA-mediated knockdown of SATB1 downregulated GATA-3 expression in differentiating human CD4(+ T cells, suggesting that SATB1 influences T(H2 lineage commitment by reprogramming gene expression. In the presence of Dickkopf 1 (Dkk1, an inhibitor of Wnt signalling, GATA-3 is downregulated and the expression of signature T(H2 cytokines such as IL-4, IL-10, and IL-13 is reduced, indicating that Wnt signalling is essential for T(H2 differentiation. Knockdown of beta-catenin also produced similar results, confirming the role of Wnt/beta-catenin signalling in T(H2 differentiation. Furthermore, chromatin immunoprecipitation analysis revealed that SATB1 recruits beta-catenin and p300 acetyltransferase on GATA-3 promoter in differentiating T(H2 cells in a Wnt-dependent manner. SATB1 coordinates T(H2 lineage commitment by reprogramming gene expression. The SATB1:beta-catenin complex activates a number of SATB1 regulated genes, and hence this study has potential to find novel Wnt responsive genes. These results demonstrate that SATB1

  2. The challenges for global harmonisation of food safety norms and regulations: issues for India.

    Science.gov (United States)

    Prakash, Jamuna

    2014-08-01

    Safe and adequate food is a human right, safety being a prime quality attribute without which food is unfit for consumption. Food safety regulations are framed to exercise control over all types of food produced, processed and sold so that the customer is assured that the food consumed will not cause any harm. From the Indian perspective, global harmonisation of food regulations is needed to improve food and nutrition security, the food trade and delivery of safe ready-to-eat (RTE) foods at all places and at all times. The Millennium Development Goals (MDGs) put forward to transform developing societies incorporate many food safety issues. The success of the MDGs, including that of poverty reduction, will in part depend on an effective reduction of food-borne diseases, particularly among the vulnerable group, which includes women and children. Food- and water-borne illnesses can be a serious health hazard, being responsible for high incidences of morbidity and mortality across all age groups of people. Global harmonisation of food regulations would assist in facilitating food trade within and outside India through better compliance, ensuring the safety of RTE catered foods, as well as addressing issues related to the environment. At the same time, regulations need to be optimum, as overregulation may have undue negative effects on the food trade. © 2013 Society of Chemical Industry.

  3. Hydrogen Monitoring Requirements in the Global Technical Regulation on Hydrogen and Fuel Cell Vehicles: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Buttner, William; Rivkin, Carl; Burgess, Robert; Hartmann, Kevin; Bubar, Max; Post, Matthew; Boon-Brett, Lois; Weidner, Eveline; Moretto, Pietro

    2016-07-01

    The United Nations Global Technical Regulation (GTR) Number 13 (Global Technical Regulation on Hydrogen and Fuel Cell Vehicles) is the defining document regulating safety requirements in hydrogen vehicles, and in particular fuel cell electric vehicles (FCEV). GTR Number 13 has been formally implemented and will serve as the basis for the national regulatory standards for FCEV safety in North America (Canada, United States), Japan, Korea, and the European Union. The GTR defines safety requirement for these vehicles, including specifications on the allowable hydrogen levels in vehicle enclosures during in-use and post-crash conditions and on the allowable hydrogen emissions levels in vehicle exhaust during certain modes of normal operation. However, in order to be incorporated into national regulations, that is, in order to be binding, methods to verify compliance to the specific requirements must exist. In a collaborative program, the Sensor Laboratories at the National Renewable Energy Laboratory in the United States and the Joint Research Centre, Institute for Energy and Transport in the Netherlands have been evaluating and developing analytical methods that can be used to verify compliance to the hydrogen release requirement as specified in the GTR.

  4. Acetyl-CoA Carboxylase Regulates Global Histone Acetylation*♦

    Science.gov (United States)

    Galdieri, Luciano; Vancura, Ales

    2012-01-01

    Histone acetylation depends on intermediary metabolism for supplying acetyl-CoA in the nucleocytosolic compartment. However, because nucleocytosolic acetyl-CoA is also used for de novo synthesis of fatty acids, histone acetylation and synthesis of fatty acids compete for the same acetyl-CoA pool. The first and rate-limiting reaction in de novo synthesis of fatty acids is carboxylation of acetyl-CoA to form malonyl-CoA, catalyzed by acetyl-CoA carboxylase. In yeast Saccharomyces cerevisiae, acetyl-CoA carboxylase is encoded by the ACC1 gene. In this study, we show that attenuated expression of ACC1 results in increased acetylation of bulk histones, globally increased acetylation of chromatin histones, and altered transcriptional regulation. Together, our data indicate that Acc1p activity regulates the availability of acetyl-CoA for histone acetyltransferases, thus representing a link between intermediary metabolism and epigenetic mechanisms of transcriptional regulation. PMID:22580297

  5. Sensitive and specific detection of Xanthomonas campestris pv. vesicatoria by PCR using pathovar-specific primers based on rhs family gene sequences.

    Science.gov (United States)

    Park, Dong Suk; Shim, Jae Kyung; Kim, Jung Sun; Lim, Chun Keun; Shrestha, Rosemary; Hahn, Jang Ho; Kim, Hong Gi

    2009-01-01

    The present study describes PCR assay to detect bacterial spot caused by Xanthomonas campestris pv. vesicatoria in pepper and tomato. One set of PCR primer was developed to amplify gene required for an rhs family gene homologous to rhsA, cell envelope biogenesis, outer membrane. Only a PCR product of a 517bp was produced in PCR reaction with the Xanthomonas campestris pv. vesicatoria (XCVF/XCVR) primer set. A specific, and highly sensitive and rapid PCR assay for the detection of X. campestris pv. vesicatoria was achieved. The protocol can be used as a reliable diagnostic tool for specific detection of X. campestris pv. vesicatoria in pepper or tomato.

  6. Studies of the spore walls of Agaricus bisporus and Agaricus campestris.

    Science.gov (United States)

    Mendoza, C G; Leal, J A; Novaes-Ledieu, M

    1979-01-01

    The composition and ultrastructure of spore walls of Agaricus bisporus and Agaricus campestris were compared by chemical and enzymatic assays and electron microscopy. Polymers of N-acetylglucosamine (chitin) and glucosamine (chitosan) were the major carbohydrate wall components of both species. The chitin to chitosan ratio in the spore walls of A. bisporus was about 0.38, while in A. campestris it was about 2.8 These polymers were associated with proteins, lipids (readily extractable and bound), melanin, and a low content of beta-glucan. The quantity of protein, total lipid, melanin, or beta-glucan was similar in spore walls of both species. With the electron microscopy, the spore walls appeared as two well-defined layers which may correspond to microfibrils of chitin and chitosan in which the electron-dense melanin was located in the external layer.

  7. Wnt/β-catenin signaling in osteoblasts regulates global energy metabolism.

    Science.gov (United States)

    Yao, Qianqian; Yu, Caixia; Zhang, Xiuzhen; Zhang, Keqin; Guo, Jun; Song, Lige

    2017-04-01

    Obesity, diabetes and osteoporosis have become a major public heath burden, and understanding the underlying mechanisms of these pathophysiological process will benefit their treatment. Osteoblast lineage cells in charge of the bone formation have been showed to participate in the whole-body energy metabolism. In this study, we identify that wnt/β-catenin signaling in osteoblasts could regulate global energy metabolism, including glucose homeostasis, fat accumulation and energy expenditure. Mice lacking β-catenin specifically in osteoblasts postnatally exhibit decreased bone mass, increased glucose level, decreased insulin production, decreased fat accumulation and increased energy expenditure. Osteocalcin supplement can rescue the impaired glucose balance by improving insulin production but cannot influence the abnormal fat accumulation and energy expenditure. Osteoprotegerin (OPG) overexpression exclusively in osteoblasts in β-catenin deletion mice can normalize not only the decreased bone mass but also the decreased fat accumulation and increased energy expenditure. The effect of β-catenin deletion and OPG overexpression in osteoblasts on global energy metabolism had no relation with inguinal fat browning. These results suggest that the regulation of bone on energy metabolism and fat accumulation is not mediated exclusively by osteocalcin. Our findings may provide a new insight into the regulation of bone on fat accumulation and energy metabolism. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Enhanced fructooligosaccharides and inulinase production by a Xanthomonas campestris pv. phaseoli KM 24 mutant.

    Science.gov (United States)

    Naidoo, Kameshnee; Ayyachamy, Manimaran; Permaul, Kugen; Singh, Suren

    2009-08-01

    Xanthomonas campestris pv phaseoli produced an extracellular endoinulinase (9.24 +/- 0.03 U mL(-1)) in an optimized medium comprising of 3% sucrose and 2.5% tryptone. X. campestris pv. phaseoli was further subjected to ethylmethanesulfonate mutagenesis and the resulting mutant, X. campestris pv. phaseoli KM 24 demonstrated inulinase production of 22.09 +/- 0.03 U mL(-1) after 18 h, which was 2.4-fold higher than that of the wild type. Inulinase production by this mutant was scaled up using sucrose as a carbon source in a 5-L fermenter yielding maximum volumetric (21,865 U L(-1) h(-1)) and specific (119,025 U g(-1) h(-1)) productivities of inulinase after 18 h with an inulinase/invertase ratio of 2.6. A maximum FOS production of 11.9 g L(-1) h(-1) and specific productivity of 72 g g(-1) h(-1) FOS from inulin were observed in a fermenter, when the mutant was grown on medium containing 3% inulin and 2.5% tryptone. The detection of mono- and oligosaccharides in inulin hydrolysates by TLC analysis indicated the presence of an endoinulinase. This mutant has potential for large-scale production of inulinase and fructooligosaccharides.

  9. Patterns of globalized reproduction: Egg cells regulation in Israel and Austria.

    Science.gov (United States)

    Shalev, Carmel; Werner-Felmayer, Gabriele

    2012-04-18

    Since the successful introduction of in vitro fertilization in 1978, medically assisted reproduction (MAR) has proliferated in multiple clinical innovations. Consequently, egg cells have become an object of demand for both infertility treatment and stem cell research, and this raises complex legal, ethical, social and economic issues.In this paper we compare how the procurement and use of human egg cells is regulated in two countries: Israel and Austria. Israel is known for its scientific leadership, generous public funding, high utilization and liberal regulation of assisted reproductive technology (ART). Austria lies at the other extreme of the regulatory spectrum in terms of restrictions on reproductive interventions.In both countries, however, there is a constant increase in the use of the technology, and recent legal developments make egg cells more accessible. Also, in both countries the scarcity of egg cells in concert with the rising demand for donations has led to the emergence of cross-border markets and global 'reproductive tourism' practices. In Israel, in particular, a scandal known as the 'eggs affair' was followed by regulation that allowed egg cell donations from outside the country under certain conditions.Cross-border markets are developed by medical entrepreneurs, driven by global economic gaps, made possible by trans-national regulatory lacunae and find expression as consumer demand. The transnational practice of egg cell donations indicates the emergence of a global public health issue, but there is a general lack of medical and epidemiological data on its efficacy and safety. We conclude that there is need for harmonisation of domestic laws and formulation of new instruments for international governance.

  10. Patterns of globalized reproduction: Egg cells regulation in Israel and Austria

    Directory of Open Access Journals (Sweden)

    Shalev Carmel

    2012-04-01

    Full Text Available Abstract Since the successful introduction of in vitro fertilization in 1978, medically assisted reproduction (MAR has proliferated in multiple clinical innovations. Consequently, egg cells have become an object of demand for both infertility treatment and stem cell research, and this raises complex legal, ethical, social and economic issues. In this paper we compare how the procurement and use of human egg cells is regulated in two countries: Israel and Austria. Israel is known for its scientific leadership, generous public funding, high utilization and liberal regulation of assisted reproductive technology (ART. Austria lies at the other extreme of the regulatory spectrum in terms of restrictions on reproductive interventions. In both countries, however, there is a constant increase in the use of the technology, and recent legal developments make egg cells more accessible. Also, in both countries the scarcity of egg cells in concert with the rising demand for donations has led to the emergence of cross-border markets and global 'reproductive tourism' practices. In Israel, in particular, a scandal known as the 'eggs affair' was followed by regulation that allowed egg cell donations from outside the country under certain conditions. Cross-border markets are developed by medical entrepreneurs, driven by global economic gaps, made possible by trans-national regulatory lacunae and find expression as consumer demand. The transnational practice of egg cell donations indicates the emergence of a global public health issue, but there is a general lack of medical and epidemiological data on its efficacy and safety. We conclude that there is need for harmonisation of domestic laws and formulation of new instruments for international governance.

  11. GLOBAL FINANCIAL CRISIS 2008 CAUSES AND CONSEQUENCES FOR RUSSIAN MACROPRUDENTIAL REGULATION

    Directory of Open Access Journals (Sweden)

    Егор Николаевич Поляков

    2013-09-01

    Full Text Available This article analyzes the impact of volatility in global financial markets on the economy of developing countries and the analysis of factors contributing to a greater or lesser degree of vulnerability of the financial systems of developing countries in the global crisis of 2008-2010. Particular attention is paid to the influence of the global financial crisis on the economies of the two groups of developing countries of Southeast Asia and Central and Eastern Europe. On the basis of the analysis due to the dynamics of the main macroeconomic indicators of the Russian Federation during the acute phase of the crisis. The author presents an analysis of the vulnerability of the Russian economy in the event of possible instability in global financial markets at present. The author came to the conclusion that the main reason for which in 2009 the level of GDP growth Russia won 178 seats out of 184 countries, were 2 groups of errors. The first group of errors - errors are system of macro-prudential regulation made by the Central Bank from 2002 to 2007, such as: lack of control and regulation of borrowings of the private and banking sectors to foreign markets, as well as in the domestic market in foreign currency, the loss of control over domestic financial markets, such as: the interbank lending market, the stock market. The second group of errors - errors it committed securities during the crisis. The first error of the Central Bank - a rejection Vat refinance foreign debt of non-financial sector, resulting in an acute liquidity crisis. The second error is stretched for a few months, not a one-time devaluation of the ruble. Price of the second error was 200 billion USD, which the Central Bank lost and speculators earned.DOI: http://dx.doi.org/10.12731/2218-7405-2013-9-4

  12. The Growth of Private Regulation of Labor Standards in Global Supply Chains

    DEFF Research Database (Denmark)

    Knudsen, Jette Steen

    2013-01-01

    Multinational corporations (MNCs) have come under pressure to adopt private regulatory initiatives such as supplier codes of conduct in order to address poor working conditions in global supply chain factories. While a well-known literature explores drivers and outcomes of such monitoring schemes...... on the Business for Social Compliance Initiative (BSCI), this article examines the positions of private actors, who demand and supply private regulation as well as the positions of those firms, who are the targets of such schemes. As the BSCI has grown its membership, MNCs increasingly request that SMEs meet BSCI...

  13. The global regulator LaeA controls production of citric acid and endoglucanases in Aspergillus carbonarius.

    Science.gov (United States)

    Linde, Tore; Zoglowek, Marta; Lübeck, Mette; Frisvad, Jens Christian; Lübeck, Peter Stephensen

    2016-08-01

    The global regulatory protein LaeA is known for regulating the production of many kinds of secondary metabolites in Aspergillus species, as well as sexual and asexual reproduction, and morphology. In Aspergillus carbonarius, it has been shown that LaeA regulates production of ochratoxin. We have investigated the regulatory effect of LaeA on production of citric acid and cellulolytic enzymes in A. carbonarius. Two types of A. carbonarius strains, having laeA knocked out or overexpressed, were constructed and tested in fermentation. The knockout of laeA significantly decreased the production of citric acid and endoglucanases, but did not reduce the production of beta-glucosidases or xylanases. The citric acid accumulation was reduced with 74-96 % compared to the wild type. The endoglucanase activity was reduced with 51-78 %. Overexpression of LaeA seemed not to have an effect on citric acid production or on cellulose or xylanase activity.

  14. Two non-consensus Clp binding sites are involved in upregulation of the gum operon involved in xanthan polysaccharide synthesis in Xanthomonas campestris pv. campestris.

    Science.gov (United States)

    Chen, Chih-Hua; Lin, Nien-Tsung; Hsiao, Yi-Min; Yang, Chiou-Ying; Tseng, Yi-Hsiung

    2010-09-01

    Biosynthesis of xanthan polysaccharide, a virulence factor of phytopathogenic Xanthomonas campestris pv. campestris (Xcc), involves the gum operon and the cyclic AMP receptor protein (CRP) homologue Clp. Clp was shown to have the same DNA binding specificity as the CRP at positions 5, 6, and 7 (GTG motif) of the left arm. Therefore, Clp binding sites (CBSs) have typically been identified by pattern searching of the Xcc genome using the consensus CRP binding sequence. Here, results of a reporter assay and electrophoretic mobility shift assay suggest that Clp upregulates the gum operon by binding to two non-consensus sites, in which a more conserved right arm may compensate for the lack of conservation in the left arm, a high GC content in the central region (6 bp) may be important for binding, and binding may be enhanced if the GC-rich central region is palindromic. These suggest that atypical CBSs exist in Xcc promoters and that Clp, while retaining the capacity to bind typical CBSs, has evolved to bind atypical CBS because: 1) Clp shares only moderate homology with the CRP and is modulated by cyclic di-GMP; and 2) Xcc has a higher GC content (65%) than Escherichia coli (50%). Copyright 2010 Elsevier Masson SAS. All rights reserved.

  15. Conformational changes associated with the binding of zinc acetate at the putative active site of XcTcmJ, a cupin from Xanthomonas campestris pv. campestris.

    Science.gov (United States)

    Axelrod, Herbert L; Kozbial, Piotr; McMullan, Daniel; Krishna, S Sri; Miller, Mitchell D; Abdubek, Polat; Acosta, Claire; Astakhova, Tamara; Carlton, Dennis; Caruthers, Jonathan; Chiu, Hsiu Ju; Clayton, Thomas; Deller, Marc C; Duan, Lian; Elias, Ylva; Feuerhelm, Julie; Grzechnik, Slawomir K; Grant, Joanna C; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K; Klock, Heath E; Knuth, Mark W; Kumar, Abhinav; Marciano, David; Morse, Andrew T; Murphy, Kevin D; Nigoghossian, Edward; Okach, Linda; Oommachen, Silvya; Paulsen, Jessica; Reyes, Ron; Rife, Christopher L; Tien, Henry J; Trout, Christina V; van den Bedem, Henry; Weekes, Dana; White, Aprilfawn; Xu, Qingping; Zubieta, Chloe; Hodgson, Keith O; Wooley, John; Elsliger, Marc André; Deacon, Ashley M; Godzik, Adam; Lesley, Scott A; Wilson, Ian A

    2010-10-01

    In the plant pathogen Xanthomonas campestris pv. campestris, the product of the tcmJ gene, XcTcmJ, encodes a protein belonging to the RmlC family of cupins. XcTcmJ was crystallized in a monoclinic space group (C2) in the presence of zinc acetate and the structure was determined to 1.6 Å resolution. Previously, the apo structure has been reported in the absence of any bound metal ion [Chin et al. (2006), Proteins, 65, 1046-1050]. The most significant difference between the apo structure and the structure of XcTcmJ described here is a reorganization of the binding site for zinc acetate, which was most likely acquired from the crystallization solution. This site is located in the conserved metal ion-binding domain at the putative active site of XcTcmJ. In addition, an acetate was also bound within coordination distance of the zinc. In order to accommodate this binding, rearrangement of a conserved histidine ligand is required as well as several nearby residues within and around the putative active site. These observations indicate that binding of zinc serves a functional role in this cupin protein.

  16. Refined annotation of the complete genome of the phytopathogenic and xanthan producing Xanthomonas campestris pv. campestris strain B100 based on RNA sequence data.

    Science.gov (United States)

    Alkhateeb, Rabeaa S; Rückert, Christian; Rupp, Oliver; Pucker, Boas; Hublik, Gerd; Wibberg, Daniel; Niehaus, Karsten; Pühler, Alfred; Vorhölter, Frank-Jörg

    2017-07-10

    Bioinformatics tools and gene expression data were applied to identify new genes and to enhance the accuracy in genomic feature predictions for Xanthomonas campestris pv. campestris (Xcc) B100, a pathogen of cruciferous plants and model strain for the biosynthesis of xanthan, a polysaccharide with a multitude of commercial applications as a thickening agent. Results from 5'-enriched end RNA sequencing (RNA-seq) and total transcriptome RNA-seq experiments were used for this purpose. Functional gene annotations were updated where new evidence had emerged and start codon predictions were enhanced for 153 protein-coding genes (CDS). In total, 32 novel CDS, and 176 novel RNA genes and features were predicted, among them 77 isogenes of the small non-coding RNA sX9. Furthermore, the RNA-seq data facilitated the identification of 848 operons that included a total of 2551 CDS besides 1667 CDS that were mono-cistronically expressed. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Binding motifs in bacterial gene promoters modulate transcriptional effect of global regulators

    Energy Technology Data Exchange (ETDEWEB)

    Leuze, Michael Rex [ORNL; Karpinets, Tatiana V [ORNL; Syed, Mustafa H [ORNL; Beliaev, Alexander S [ORNL; Uberbacher, Edward C [ORNL

    2012-01-01

    Bacterial gene regulation involves transcription factors (TFs) that influence the expression of many genes. Global regulators, including CRP (cAMP Receptor Protein), ArcA, and FNR, can modulate the transcriptional activity of multiple operons. The similarity of a regulatory element s sequence to a TF s consensus binding site (BS) and the position of the regulatory element in an operon promoter are considered the most important determinants of this TF s regulatory influence. In this study we explore the hypothesis that the number of TFBS half-sites (where a half-site is one half of the palindromic BS consensus sequence, which we shall refer to as a binding motif or a BM) of a global regulator in an operon s promoter plays an important role in the operon s transcriptional regulation. We examine empirical data from transcriptional profiling of the CRP regulon in Shewanella oneidenses MR 1 and Escherichia coli, and of the ArcA regulon in S. oneidenses MR 1. We compare the power of CRP BM counts and of full, symmetrical CRP TFBS characteristics, namely similarity to consensus and location, to predict CRP-induced transcriptional activity. We find that CRP BM counts have a nonlinear effect on CRP-dependent transcriptional activity and predict this activity better than full-length TFBS quality or location. Regression analysis indicates that IHF (Integration Host Factor) and ArcA have synergistic effects on CRP-induced gene transcription, positive and negative, respectively. Based on these results, we propose that the fine-tuning of bacterial transcriptional activity by CRP may involves not only the bending of the operon promoter, facilitated by CRP in cooperation with the histone-like protein IHF, but also the cumulative binding affinity of multiple weak BMs.

  18. Globalization

    Directory of Open Access Journals (Sweden)

    Tulio Rosembuj

    2006-12-01

    Full Text Available There is no singular globalization, nor is the result of an individual agent. We could start by saying that global action has different angles and subjects who perform it are different, as well as its objectives. The global is an invisible invasion of materials and immediate effects.

  19. Strengthening global health security by embedding the International Health Regulations requirements into national health systems.

    Science.gov (United States)

    Kluge, Hans; Martín-Moreno, Jose Maria; Emiroglu, Nedret; Rodier, Guenael; Kelley, Edward; Vujnovic, Melitta; Permanand, Govin

    2018-01-01

    The International Health Regulations (IHR) 2005, as the overarching instrument for global health security, are designed to prevent and cope with major international public health threats. But poor implementation in countries hampers their effectiveness. In the wake of a number of major international health crises, such as the 2014 Ebola and 2016 Zika outbreaks, and the findings of a number of high-level assessments of the global response to these crises, it has become clear that there is a need for more joined-up thinking between health system strengthening activities and health security efforts for prevention, alert and response. WHO is working directly with its Member States to promote this approach, more specifically around how to better embed the IHR (2005) core capacities into the main health system functions. This paper looks at how and where the intersections between the IHR and the health system can be best leveraged towards developing greater health system resilience. This merging of approaches is a key component in pursuit of Universal Health Coverage and strengthened global health security as two mutually reinforcing agendas.

  20. Semi-global regulation of output synchronization for heterogeneous networks of non-introspective, invertible agents subject to actuator saturation

    NARCIS (Netherlands)

    Yang, Tao; Stoorvogel, Antonie Arij; Grip, H°avard Fjær; Saberi, Ali

    2014-01-01

    In this paper, we consider the semi-global regulation of output synchronization problem for heterogeneous networks of invertible linear agents subject to actuator saturation. That is, we regulate the output of each agent according to an a priori specified reference model. The network communication

  1. Effect of Scarification, Self-Inhibition, and Sowing Depth on Seed Germination of Lupinus campestris Efecto de la Escarificación, Autoinhibición y Profundidad de Siembra sobre la Germinación de Semillas de Lupinus campestris

    OpenAIRE

    Pedro Gutiérrez Nava; Fernando De León González; Jorge Etchevers Barra; Alejandro Casas Fernández

    2010-01-01

    Lupinus campestris Schltdl. & Cham. grows in shallow fields and disturbed areas of Central Mexico. It has potential to improve soil fertility and as fodder. Seeds of L. campestris show dormancy, and the technology needed to increase its potential use requires information about conditions favouring seed germination. The aim of this study was to evaluate the seed germination responseof L. campestris under controlled (laboratory) and natural field conditions. Under laboratory conditions, 2 yr ol...

  2. RovA, a global regulator of Yersinia pestis, specifically required for bubonic plague.

    Science.gov (United States)

    Cathelyn, Jason S; Crosby, Seth D; Lathem, Wyndham W; Goldman, William E; Miller, Virginia L

    2006-09-05

    The pathogenic species of Yersinia contain the transcriptional regulator RovA. In Yersinia pseudotuberculosis and Yersinia enterocolitica, RovA regulates expression of the invasion factor invasin (inv), which mediates translocation across the intestinal epithelium. A Y. enterocolitica rovA mutant has a significant decrease in virulence by LD(50) analysis and an altered rate of dissemination compared with either wild type or an inv mutant, suggesting that RovA regulates multiple virulence factors. Here, we show the involvement of RovA in the virulence of Yersinia pestis, which naturally lacks a functional inv gene. A Y. pestis DeltarovA mutant is attenuated approximately 80-fold by LD(50) and is defective in dissemination/colonization of spleens and lungs after s.c. inoculation. However, the DeltarovA mutant is only slightly attenuated when given via an intranasal or i.p. route, indicating a more important role for RovA in bubonic plague than pneumonic plague or systemic infection. Microarray analysis was used to define the RovA regulon. The psa locus was among the most highly down-regulated loci in the DeltarovA mutant. A DeltapsaA mutant had a significant dissemination defect after s.c. infection but only slight attenuation by the pneumonic-disease model, closely mimicking the virulence defect seen with the DeltarovA mutant. DNA-binding studies revealed that RovA specifically interacts with the psaE and psaA promoter regions, indicating a direct role for RovA in regulating this locus. Thus, RovA appears to be a global transcription factor in Y. pestis and, through its regulatory influence on genes such as psaEFABC, contributes to the virulence of Y. pestis.

  3. World integrated medicine forum on the regulation of homoeopathic medicinal products: National and global strategies

    Directory of Open Access Journals (Sweden)

    Harleen Kaur

    2017-01-01

    Full Text Available The first World Integrated Medicine Forum on the regulation of homoeopathic medicinal products included 50 delegates from 25 countries to discuss the current state of regulation of homoeopathic medicinal products (HMPs. The stakeholders in attendance included government officials, manufacturers, pharmacopoeia organisations, pharmacists, and healthcare providers worldwide. The Minister of Ayurveda, Yoga, Unani, Siddha and Homoeopathy from India, who is likely the only high ranking national official in the world specifically dedicated to oversight of traditional medicines including Homoeopathy, was the keynote speaker for the meeting. The core presentations delivered information on the country-to-country variance in regulatory requirements for homoeopathic medicine manufacture and marketing. Different speakers addressed the current pharmacopeia structures in various countries, variance in premarket approval process, regulatory frameworks for homoeopathic medicines, labelling requirements, safety requirements, marketing approaches and good manufacturing practices. Debates focused on quality control testing, stability of intermediate stocks, shelf life of finished products, pre-market approval process and labelling and they shed light on regional differences in regulation. A lengthy discussion was held on the potential value of harmonisation of pharmacopoeias, manufacturing standards, safety evaluation and labelling. The group consensus was to meet again to pursue specific topics. Daily summaries of take-away points are provided at the end of each day's talk summaries. Much acclaim was won by the organisers for materialising this unique forum which proved to be an apt platform for rigorous discussions on lesser discussed, but very vital points such as regulations of HMPs, harmonisation of pharmacopeias and linking industry and regulators' sectors for unified efforts for global development of Homoeopathy.

  4. Trm9-Catalyzed tRNA Modifications Regulate Global Protein Expression by Codon-Biased Translation.

    Directory of Open Access Journals (Sweden)

    Wenjun Deng

    2015-12-01

    Full Text Available Post-transcriptional modifications of transfer RNAs (tRNAs have long been recognized to play crucial roles in regulating the rate and fidelity of translation. However, the extent to which they determine global protein production remains poorly understood. Here we use quantitative proteomics to show a direct link between wobble uridine 5-methoxycarbonylmethyl (mcm5 and 5-methoxy-carbonyl-methyl-2-thio (mcm5s2 modifications catalyzed by tRNA methyltransferase 9 (Trm9 in tRNAArg(UCU and tRNAGlu(UUC and selective translation of proteins from genes enriched with their cognate codons. Controlling for bias in protein expression and alternations in mRNA expression, we find that loss of Trm9 selectively impairs expression of proteins from genes enriched with AGA and GAA codons under both normal and stress conditions. Moreover, we show that AGA and GAA codons occur with high frequency in clusters along the transcripts, which may play a role in modulating translation. Consistent with these results, proteins subject to enhanced ribosome pausing in yeast lacking mcm5U and mcm5s2U are more likely to be down-regulated and contain a larger number of AGA/GAA clusters. Together, these results suggest that Trm9-catalyzed tRNA modifications play a significant role in regulating protein expression within the cell.

  5. Detection of the plant pathogenic bacterium Xanthomonas campestris pv. Campestris in seed extracts of Brassica sp. Applying fluorescent antibodies and flow cytometry.

    Science.gov (United States)

    Chitarra, L G; Langerak, C J; Bergervoet, J H W; van den Bulk, R W

    2002-02-01

    Xanthomonas campestris pv. campestris (Xcc) is a seed-transmitted plant pathogenic bacterium that causes black rot of crucifers. Seed lots and plants are screened for contamination with this pathogen using plating or serological assays. These methods, however, are time consuming and not very sensitive, respectively. Therefore, flow cytometry (FCM) was evaluated as a tool for the rapid detection and quantification of Xcc cells labeled with a mixture of specific fluorescein isothicyanate (FITC)-monoclonal antibodies (mAb) in pure culture, in mixed cultures of Xcc with either the common saprophyte Pseudomonas fluorescens (Psf) or a nonpathogenic X. campestris isolate (Xc), and in crude seed extracts. The mAb 18G12, conjugated with FITC, was tested at dilutions of 1:50, 1:100, 1:200, and 1:400. For mixed suspensions of Xcc and Psf, mAb 18G12 was used at a dilution of 1:100. The combination of mAbs 18G12, 2F4, and 20H6, all conjugated with FITC, was used at a dilution of 1:100 for the detection and quantification of Xcc cells in mixed suspensions containing Xcc and Xc and in crude seed extracts. The analyses were performed with a Coulter EPICS XL-MCL flow cytometer, at low flow rate during 2 min. Using FCM, Xcc cells labeled with FITC-conjugated mAbs (18G12, 2F4, and 20H6) were detected and quantified rapidly at low numbers, i.e., 10(3) colony-forming units per milliliter in pure and in mixed cultures with Psf. The presence of the nonpathogenic Xc in the seed extracts did not interfere with the FCM results. Xcc cells were distinguished from the cells of other organisms and from small particles present in the seed extract based on the high-intensity fluorescence of the labeled cells. The application of FCM in combination with FITC-conjugated mAbs appears to be a promising technique for the detection and quantification of Xcc cells in seed extracts of crucifers. Copyright 2002 Wiley-Liss, Inc.

  6. Association of the Cytoplasmic Membrane Protein XpsN with the Outer Membrane Protein XpsD in the Type II Protein Secretion Apparatus of Xanthomonas campestris pv. Campestris

    Science.gov (United States)

    Lee, Hsien-Ming; Wang, Kuan-Cheng; Liu, Yi-Ling; Yew, Hsin-Yan; Chen, Ling-Yun; Leu, Wei-Ming; Chen, David Chanhen; Hu, Nien-Tai

    2000-01-01

    An xps gene cluster composed of 11 open reading frames is required for the type II protein secretion in Xanthomonas campestris pv. campestris. Immediately upstream of the xpsD gene, which encodes an outer membrane protein that serves as the secretion channel by forming multimers, there exists an open reading frame (previously designated ORF2) that could encode a protein of 261 amino acid residues. Its N-terminal hydrophobic region is a likely membrane-anchoring sequence. Antibody raised against this protein could detect in the wild-type strain of X. campestris pv. campestris a protein band with an apparent molecular mass of 36 kDa by Western blotting. Its aberrant slow migration in sodium dodecyl sulfate-polyacrylamide gels might be due to its high proline content. We designated this protein XpsN. By constructing a mutant strain with an in-frame deletion of the chromosomal xpsN gene, we demonstrated that it is required for the secretion of extracellular enzyme by X. campestris pv. campestris. Subcellular fractionation studies indicated that the XpsN protein was tightly associated with the membrane. Sucrose gradient sedimentation followed by immunoblot analysis revealed that it primarily appeared in the cytoplasmic membrane fractions. Immune precipitation experiments indicated that the XpsN protein was coprecipitated with the XpsD protein. In addition, the XpsN protein was co-eluted with the (His)6-tagged XpsD protein from the metal affinity chromatography column. All observations suggested that the XpsN protein forms a stable complex with the XpsD protein. In addition, immune precipitation analysis of the XpsN protein with various truncated XpsD proteins revealed that the C-terminal region of the XpsD protein between residues 650 and 759 was likely to be involved in complex formation between the two. PMID:10692359

  7. Preferential exclusion of hybrids in mixed pollinations between oilseed rape (Brassica napus) and weedy B. campestris (Brassicaceae)

    DEFF Research Database (Denmark)

    Hauser, T.P.; Bagger Jørgensen, Rikke; Østergård, Hanne

    1997-01-01

    In most experimental hybridizations between oilseed rape (Brassica napus) and weedy B. campestris, either intra- or interspecific pollen has been applied to individual flowers. Under field conditions, however, stigmas will often receive a mixture of the two types of pollen, thereby allowing...... for competition between male gametophytes and/or seeds within pods. To test whether competition influences the success of hybridization, pollen from the two species was mixed in different proportions and applied to stigmas of both species. The resulting seeds were scored for paternity by isozyme and randomly...... survival of hybrid zygotes in B. napus pods. This is in contrast to the higher survival of hybrid seeds in B. napus than in B. campestris pods when pollinations are made with pure pollen. Altogether, the likelihood of a foreign pollen grain producing a seed was much lower on B. napus than on B. campestris...

  8. A 3.9-kb DNA region of Xanthomonas campestris pv. campestris that is necessary for lipopolysaccharide production encodes a set of enzymes involved in the synthesis of dTDP-rhamnose.

    OpenAIRE

    Köplin, R; Wang, G.; Hötte, B; Priefer, U B; Pühler, A

    1993-01-01

    By mutational analysis it was found that a 3.9-kb SmaI-XhoII DNA fragment of Xanthomonas campestris pv. campestris is involved in lipopolysaccharide (LPS) biosynthesis. LPS samples isolated from different mutants carrying mutations in the 3.9-kb SmaI-XhoII DNA fragment exhibited banding patterns in silver-stained sodium dodecyl sulfate-polyacrylamide gels markedly different from that of the wild-type LPS. Moreover, comparison of the monosaccharide composition obtained by high-performance anio...

  9. LINE-1 activation after fertilization regulates global chromatin accessibility in the early mouse embryo.

    Science.gov (United States)

    Jachowicz, Joanna W; Bing, Xinyang; Pontabry, Julien; Bošković, Ana; Rando, Oliver J; Torres-Padilla, Maria-Elena

    2017-10-01

    After fertilization, to initiate development, gametes are reprogramed to become totipotent. Approximately half of the mammalian genome consists of repetitive elements, including retrotransposons, some of which are transcribed after fertilization. Retrotransposon activation is generally assumed to be a side effect of the extensive chromatin remodeling underlying the epigenetic reprogramming of gametes. Here, we used a targeted epigenomic approach to address whether specific retrotransposon families play a direct role in chromatin organization and developmental progression. We demonstrate that premature silencing of LINE-1 elements decreases chromatin accessibility, whereas prolonged activation prevents the gradual chromatin compaction that occurs naturally in developmental progression. Preventing LINE-1 activation and interfering with its silencing decreases developmental rates independently of the coding nature of the LINE-1 transcript, thus suggesting that LINE-1 functions primarily at the chromatin level. Our data suggest that activation of LINE-1 regulates global chromatin accessibility at the beginning of development and indicate that retrotransposon activation is integral to the developmental program.

  10. Chemical characterization of Xanthan biopolymers synthesized by Xanthomonas campestris pv pruni strains; Caracterizacao quimica de biopolimeros sintetizados por Xanthomonas campestris pv pruni

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Angelita da S.; Vendruscolo, Claire T.; Furlan, Ligia [Universidade Federal de Pelotas, RS (Brazil). Centro de Biotecnologia]. E-mail: angelita@ufpel.tche.br; claire@ufpel.tche.br; ligia@ufpel.tche.br; Galland, Griselda [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Qumica

    2001-07-01

    In this work we describe the characterisation of Xanthan biopolymers synthesized by two Xanthomonas campestris pv pruni strains, in aerobic fermentation. By chromatography on TLC we could notice the presence of Mannose monomer in higher proportion in the 82 strain with relation to the another ones. The viscosity results showed the temperature dependence. The 06 and 82 strains had their viscosity increased whereas for the 87 strain we could observe a reduction with temperature increasing. The {sup 13}C NMR spectrum of 87 strain showed the characteristic signals at approximately 92.8, 70.4 and 61.4 ppm, attributed to C1, C4 and C6 from glucose monomer, with higher intensity. (author)

  11. Significant alterations in anisotropic ice growth rate induced by the ice nucleation-active bacteria Xanthomonas campestris

    Science.gov (United States)

    Nada, Hiroki; Zepeda, Salvador; Miura, Hitoshi; Furukawa, Yoshinori

    2010-09-01

    In the present study, we found that the ice nucleation-active bacteria Xanthomonas campestris significantly altered anisotropic ice growth rate. Results of ice growth experiments in the presence of X. campestris showed that this bacterium decreased the ice crystal growth rate in the c-axis, whereas it increased growth rates in directions normal to the c-axis. These results indicate that these alterations in anisotropic growth rate are the result of selective binding of bacterial ice-nucleating proteins along the {0 0 0 1} basal plane.

  12. Global analysis of p53-regulated transcription identifies its direct targets and unexpected regulatory mechanisms

    Science.gov (United States)

    Allen, Mary Ann; Andrysik, Zdenek; Dengler, Veronica L; Mellert, Hestia S; Guarnieri, Anna; Freeman, Justin A; Sullivan, Kelly D; Galbraith, Matthew D; Luo, Xin; Kraus, W Lee; Dowell, Robin D; Espinosa, Joaquin M

    2014-01-01

    The p53 transcription factor is a potent suppressor of tumor growth. We report here an analysis of its direct transcriptional program using Global Run-On sequencing (GRO-seq). Shortly after MDM2 inhibition by Nutlin-3, low levels of p53 rapidly activate ∼200 genes, most of them not previously established as direct targets. This immediate response involves all canonical p53 effector pathways, including apoptosis. Comparative global analysis of RNA synthesis vs steady state levels revealed that microarray profiling fails to identify low abundance transcripts directly activated by p53. Interestingly, p53 represses a subset of its activation targets before MDM2 inhibition. GRO-seq uncovered a plethora of gene-specific regulatory features affecting key survival and apoptotic genes within the p53 network. p53 regulates hundreds of enhancer-derived RNAs. Strikingly, direct p53 targets harbor pre-activated enhancers highly transcribed in p53 null cells. Altogether, these results enable the study of many uncharacterized p53 target genes and unexpected regulatory mechanisms. DOI: http://dx.doi.org/10.7554/eLife.02200.001 PMID:24867637

  13. A microRNA feedback loop regulates global microRNA abundance during aging.

    Science.gov (United States)

    Inukai, Sachi; Pincus, Zachary; de Lencastre, Alexandre; Slack, Frank J

    2018-02-01

    Expression levels of many microRNAs (miRNAs) change during aging, notably declining globally in a number of organisms and tissues across taxa. However, little is known about the mechanisms or the biological relevance for this change. We investigated the network of genes that controls miRNA transcription and processing during C. elegans aging. We found that miRNA biogenesis genes are highly networked with transcription factors and aging-associated miRNAs. In particular, miR-71, known to influence life span and itself up-regulated during aging, represses alg-1/Argonaute expression post-transcriptionally during aging. Increased ALG-1 abundance in mir-71 loss-of-function mutants led to globally increased miRNA expression. Interestingly, these mutants demonstrated widespread mRNA expression dysregulation and diminished levels of variability both in gene expression and in overall life span. Thus, the progressive molecular decline often thought to be the result of accumulated damage over an organism's life may be partially explained by a miRNA-directed mechanism of age-associated decline. © 2018 Inukai et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  14. CD47 Receptor Globally Regulates Metabolic Pathways That Control Resistance to Ionizing Radiation.

    Science.gov (United States)

    Miller, Thomas W; Soto-Pantoja, David R; Schwartz, Anthony L; Sipes, John M; DeGraff, William G; Ridnour, Lisa A; Wink, David A; Roberts, David D

    2015-10-09

    Modulating tissue responses to stress is an important therapeutic objective. Oxidative and genotoxic stresses caused by ionizing radiation are detrimental to healthy tissues but beneficial for treatment of cancer. CD47 is a signaling receptor for thrombospondin-1 and an attractive therapeutic target because blocking CD47 signaling protects normal tissues while sensitizing tumors to ionizing radiation. Here we utilized a metabolomic approach to define molecular mechanisms underlying this radioprotective activity. CD47-deficient cells and cd47-null mice exhibited global advantages in preserving metabolite levels after irradiation. Metabolic pathways required for controlling oxidative stress and mediating DNA repair were enhanced. Some cellular energetics pathways differed basally in CD47-deficient cells, and the global declines in the glycolytic and tricarboxylic acid cycle metabolites characteristic of normal cell and tissue responses to irradiation were prevented in the absence of CD47. Thus, CD47 mediates signaling from the extracellular matrix that coordinately regulates basal metabolism and cytoprotective responses to radiation injury. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Distribution and harmfulness of field dodder (Cuscuta campestris Yuncker at sugar beet fields in Slovakia

    Directory of Open Access Journals (Sweden)

    Tóth Peter

    2006-01-01

    Full Text Available During 2002-2004, field surveys of field dodder (Cuscuta campestris Yunck e r in croplands were done in southwestern Slovakia. From among 150 localities surveyed, 80 were found infested by the field dodder. Within crop plants, C. campestris infested sugar beet (Beta vulgaris, alfalfa (Medicago sativa tobacco (Nicotiana tabacum, potato (Solanum tuberosum, lentil (Lens esculenta, parsley (Pastinaca sativa and onion (Allium cepa. Besides the crops, 18 weed species were also recorded. The species from the genus Polygonum (Polygonaceae were the most important and acted as a significant reservoir of field dodder in cropland. C. campestris was not found in cold climatic regions with altitude higher than 240 m. The impact of field dodder infestation on sugar beet yield was studied during the year of 2004 in two localities (Šalov and Žitavce in southwestern Slovakia. The presence of field dodder markedly reduced both, quantity and quality of sugar beet yield. Weight of heavily infested beets was reduced from 21.6 to 37.4% and sugar content from 12.0 to 15.2%. Such decline of both parameters was also recorded when field dodder was removed together with leaves of sugar beet during growing season at the end of July. The aim of the infested leaves removal was to decrease mass of field dodder seeds. Although the leaf area of sugar beet regenerates, the decrease of quality and quantity was observed. The decline was the same at both localities, no matter whether the fields were irrigated (Šalov or not (Žitavce.

  16. Searching for a trace of Artemisia campestris pollen in the air

    Directory of Open Access Journals (Sweden)

    Łukasz Grewling

    2015-12-01

    Full Text Available The aim of the study was to determinate whether Artemisia campestris was present in the vicinity of 8 pollen monitoring stations in Poland by examining temporal variations in daily average airborne Artemisia pollen data recorded by Hirst type volumetric traps. Three day moving averages of airborne Artemisia pollen were examined by Spearman’s rank correlation test. Results show that Artemisia pollen seasons in Poland generally display similar unimodal patterns (correlation coefficients r > 0.900; P < 0.05. The only exception was the Artemisia pollen concentration noted in the outskirts of Poznań (Morasko, where the bimodal pattern was revealed. Correlations between Artemisia pollen data recorded at Poznań-Morasko and the other Polish sites were the lowest in the investigated dataset; this was particularly noticeable in the second part of pollen season (r ~0.730. We show that the typical bimodal pattern in Artemisia pollen seasons, which is characteristic of the presence of both A. vulgaris (first peak and A. campestris (second peak, does not occur at the majority of sites in Poland and is restricted to the outskirts of Poznań. In fact, it was noted that the pollen monitoring site in Poznań-Centre, just 8 km from Morasko, only exhibited one peak (attributed to A. vulgaris. This shows that the influence of A. campestris on airborne pollen season curves is limited and can be largely disregarded. In addition, this study supports previous records showing that the spatial distribution of airborne Artemisia pollen within a city (urban-rural gradient can vary markedly, depending on the species composition.

  17. Global control of reaction wheel pendulum through energy regulation and extended linearization of the state variables

    Directory of Open Access Journals (Sweden)

    Oscar D. Montoya-Giraldo

    2014-01-01

    Full Text Available This paper presents the design and simulation of a global controller for the Reaction Wheel Pendulum system using energy regulation and extended linearization methods for the state feedback. The proposed energy regulation is based on the gradual reduction of the energy of the system to reach the unstable equilibrium point. The signal input for this task is obtained from the Lyapunov stability theory. The extended state feedback controller design is used to get a smooth nonlinear function that extends the region of operation to a bigger range, in contrast with the static linear state feedback obtained through the method of approximate linearization around an operating point. The general designed controller operates with a switching between the two control signals depending upon the region of operation; perturbations are applied in the control signal and the (simulated measured variables to verify the robustness and efficiency of the controller. Finally, simulations and tests using the model of the reaction wheel pendulum system, allow to observe the versatility and functionality of the proposed controller in the entire operation region of the pendulum.

  18. Global analysis of epigenetic regulation of gene expression in response to drought stress in Sorghum.

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Anireddy [Colorado State Univ., Fort Collins, CO (United States); Ben-Hur, Asa [Colorado State Univ., Fort Collins, CO (United States)

    2017-11-22

    Abiotic stresses including drought are major limiting factors of crop yields and cause significant crop losses. Acquisition of stress tolerance to abiotic stresses requires coordinated regulation of a multitude of biochemical and physiological changes, and most of these changes depend on alterations in gene expression. The goal of this work is to perform global analysis of differential regulation of gene expression and alternative splicing, and their relationship with chromatin landscape in drought sensitive and tolerant cultivars. our Iso-Seq study revealed transcriptome-wide full-length isoforms at an unprecedented scale with over 11000 novel splice isoforms. Additionally, we uncovered alternative polyadenylation sites of ~11000 expressed genes and many novel genes. Overall, Iso-Seq results greatly enhanced sorghum gene annotations that are not only useful in analyzing all our RNA-seq, ChIP-seq and ATAC-seq data but also serve as a great resource to the plant biology community. Our studies identified differentially expressed genes and splicing events that are correlated with the drought-resistant phenotype. An association between alternative splicing and chromatin accessibility was also revealed. Several computational tools developed here (TAPIS and iDiffIR) have been made freely available to the research community in analyzing alternative splicing and differential alternative splicing.

  19. Conservation of replication timing reveals global and local regulation of replication origin activity

    Science.gov (United States)

    Müller, Carolin A.; Nieduszynski, Conrad A.

    2012-01-01

    DNA replication initiates from defined locations called replication origins; some origins are highly active, whereas others are dormant and rarely used. Origins also differ in their activation time, resulting in particular genomic regions replicating at characteristic times and in a defined temporal order. Here we report the comparison of genome replication in four budding yeast species: Saccharomyces cerevisiae, S. paradoxus, S. arboricolus, and S. bayanus. First, we find that the locations of active origins are predominantly conserved between species, whereas dormant origins are poorly conserved. Second, we generated genome-wide replication profiles for each of these species and discovered that the temporal order of genome replication is highly conserved. Therefore, active origins are not only conserved in location, but also in activation time. Only a minority of these conserved origins show differences in activation time between these species. To gain insight as to the mechanisms by which origin activation time is regulated we generated replication profiles for a S. cerevisiae/S. bayanus hybrid strain and find that there are both local and global regulators of origin function. PMID:22767388

  20. Inheritance of oilseed rape (Brassica napus) RAPD markers in a backcross progeny with Brassica campestris

    DEFF Research Database (Denmark)

    Mikkelsen, T.R.; Jensen, J.; Bagger Jørgensen, Rikke

    1996-01-01

    Different cultivars/transgenic lines of oilseed rape (Brassica napus) were crossed (as females) with different cultivars/populations of Brassica campestris. All cross combinations produced seed, with an average seed set per pollination of 9.8. Backcrossing of selected interspecific hybrids (as...... markers could be assigned to six linkage groups, most probably reflecting six B. napus C-chromosomes. The presence of backcross plants with recombinant genotypes suggests that complex genetic processes can take place during the interspecific hybridisation and backcrossing in these Brassica species....... The implications of our results for the possible choice nf integration sites of transgenes in oilseed rape are discussed....

  1. Detecção, transmissão e efeito de Xanthomonas campestris pv. campestris na qualidade fisiológica de sementes de brócolis Detection, transmission and effect of Xanthomonas campestris pv. campestris in the physiological quality of broccoli seeds

    Directory of Open Access Journals (Sweden)

    Nilvanira Donizeti Tebaldi

    2007-12-01

    Full Text Available A detecção, a transmissão e o efeito de Xanthomonas campestris pv. campestris (Xcc na qualidade fisiológica de sementes de brócolis (Brassica oleracea var. italica foram avaliados, a partir de sementes obtidas de plantas ("Baron, Flórida, Hana Midori Sakata, Precoce Piracicaba de Verão, Ramoso Santana e Sabre" inoculadas com a bactéria, em condições de campo. Para a detecção do patógeno nas sementes foram utilizados os meios de cultura semi-seletivos: SX ágar, NSCAA e BSCAA; a taxa de transmissão da bactéria pelas sementes às plântulas foi avaliada usando semeadura em areia e meio de cultura contido em tubo de ensaio. Para a avaliação da qualidade fisiológica de sementes foram realizados o teste padrão de germinação e os testes de vigor: envelhecimento acelerado, índice de velocidade de emergência, crescimento de plântulas e massa seca. De acordo com os resultados, o meio de cultura semi-seletivo NSCAA foi mais eficaz para detectar Xcc em sementes de brócolis; não houve diferença significativa entre os genótipos na taxa de transmissão da bactéria pelas sementes e Xcc não afetou a germinação e o vigor das sementes.The detection, transmission and the effect of Xanthomomas campestris pv. campestris (Xcc in the physiological quality of broccoli seeds were evaluated. The seeds were obtained from inoculated field plants (`Baron', `Flórida', `Hana Midori Sakata', `Precoce Piracicaba de Verão', `Ramoso Santana' and `Sabre' genotypes with the bacterium. For the seed pathogen detection the semi-selective medium were used: starch for xanthomonads (SX agar, nutrient starch cycloheximide antibiotic agar (NSCAA and basal starch cycloheximide antibiotic agar (BSCAA; the bacteria seeds transmission percentage was evaluated using sand and test tube. The physiological seed quality was evaluated by the standard germination and vigor tests: the accelerated aging, speed of emergence, seedling growth and seedling dry weight. The

  2. Detecção, transmissão e efeito de Xanthomonas campestris pv. campestris na qualidade fisiológica de sementes de brócolis Detection, transmission and effect of Xanthomonas campestris pv. campestris in the physiological quality of broccoli seeds

    Directory of Open Access Journals (Sweden)

    Nilvanira Donizete Tebaldi

    2007-09-01

    Full Text Available A detecção, a transmissão e o efeito de Xanthomonas campestris pv. campestris (Xcc na qualidade fisiológica de sementes de brócolis (Brassica oleracea var. italica foram avaliadas, a partir de sementes obtidas de plantas ("Baron, Flórida, Hana Midori Sakata, Precoce Piracicaba de Verão, Ramoso Santana e Sabre" inoculadas com a bactéria, em condições de campo. Para a detecção do patógeno nas sementes foram utilizados os meios de cultura semi-seletivos: SX ágar, NSCAA e BSCAA; a taxa de transmissão da bactéria pelas sementes às plântulas foi avaliada usando semeadura em areia e meio de cultura contido em tubo de ensaio. Para a avaliação da qualidade fisiológica das sementes foram realizados o teste padrão de germinação e os testes de vigor: envelhecimento acelerado, índice de velocidade de emergência, crescimento das plântulas e massa seca. De acordo com os resultados, o meio de cultura semi-seletivo NSCAA foi mais eficaz para detectar Xcc em sementes de brócolis; não houve diferença significativa entre os genótipos na taxa de transmissão da bactéria pelas sementes e Xcc não afetou a germinação e o vigor das sementes.The detection, transmission and the effect of Xanthomomas campestris pv. campestris (Xcc in the physiological quality of broccoli seeds were evaluated. The seeds were obtained from inoculated field plants ('Baron', 'Flórida', 'Hana Midori Sakata', 'Precoce Piracicaba de Verão', 'Ramoso Santana' and 'Sabre' genotypes with the bacterium. For the seed pathogen detection the semi-selective medium were used: starch for xanthomonads (SX agar, nutrient starch cycloheximide antibiotic agar (NSCAA and basal starch cycloheximide antibiotic agar (BSCAA; the bacteria seeds transmission percentage was evaluated using sand and test tube. The physiological seed quality was evaluated by the standard germination and vigor tests: the accelerated aging, speed of emergence, seedling growth and seedling dry weight

  3. Global SUMO proteome responses guide gene regulation, mRNA biogenesis, and plant stress responses

    Directory of Open Access Journals (Sweden)

    Magdalena eMazur

    2012-09-01

    Full Text Available Small-ubiquitin-like MOdifier (SUMO is a key regulator of abiotic stress, disease resistance and development in plants. The identification of >350 plant SUMO targets has revealed many processes modulated by SUMO and potential consequences of SUMO on its targets. Importantly, highly related proteins are SUMO-modified in plants, yeast, and metazoans. Overlapping SUMO targets include heat-shock proteins, transcription regulators, histones, histone-modifying enzymes, proteins involved in DNA damage repair, but also proteins involved in mRNA biogenesis and nucleo-cytoplasmic transport. Proteomics studies indicate key roles for SUMO in gene repression by controlling histone (deacetylation activity at genomic loci. The responsible heavily sumoylated transcriptional repressor complexes are recruited by EAR (Ethylene-responsive element binding factor [ERF]-associated Amphiphilic Repression-motif containing transcription factors in plants. These transcription factors are not necessarily themselves a SUMO target. Conversely, SUMO acetylation prevents binding of downstream partners by preventing binding of SIMs (SUMO-interaction peptide motifs presents in these partners, while SUMO acetylation has emerged as mechanism to recruit specifically bromodomains; bromodomain are generally linked with gene activation. These findings strengthen the idea of a bidirectional sumo-/acetylation switch in gene regulation. Quantitative proteomics has highlighted that global sumoylation provides a dynamic response to protein damage involving SUMO chain-mediated protein degradation, but also SUMO E3 ligase-dependent transcription of HSP (Heat-shock protein genes. With these insights in SUMO function and novel technical advancements, we can now study SUMO dynamics in responses to (abiotic stress in plants.

  4. Hydrogen Regulation and Global Responses to Electron, Carbon and Nitrogen Sources of Methanococcus Maripaludis

    Energy Technology Data Exchange (ETDEWEB)

    Leigh, John A. [Univ. of Washington, Seattle, WA (United States)

    2013-05-20

    Methanogens catalyze the critical, methane-producing step (called methanogenesis) in the anaerobic decomposition of organic matter. This project has generated the first predictive model of global gene regulation of methanogenesis in a hydrogenotrophic methanogen, Methanococcus maripaludis. We generated a comprehensive list of genes (protein-coding and non-coding) for M. maripaludis through integrated analysis of the transcriptome structure and a newly constructed Peptide Atlas. The environment and gene-regulatory influence network (EGRIN) model of the strain was constructed from a compendium of transcriptome data that was collected over 58 different steady-state and time course experiments that were performed in chemostats or batch cultures, under a spectrum of environmental perturbations that modulated methanogenesis. Analyses of the EGRIN model have revealed novel components of methanogenesis that included at least three additional protein-coding genes of previously unknown function as well as one non-coding RNA. We discovered that at least five regulatory mechanisms act in a combinatorial scheme to inter-coordinate key steps of methanogenesis with different processes such as motility, ATP biosynthesis, and carbon assimilation. Through a combination of genetic and environmental perturbation experiments we have validated the EGRIN-predicted role of two novel transcription factors in the regulation of phosphate-dependent repression of formate dehydrogenase a key enzyme in the methanogenesis pathway. The EGRIN model demonstrates regulatory affiliations within methanogenesis as well as between methanogenesis and other cellular functions. In addition, we have published an analysis of transcriptome architecture in M. maripaludis and an analysis of the effects of H2 and formate on growth yield and regulation of methanogenesis in M. maripaludis.

  5. A 3.9-kb DNA region of Xanthomonas campestris pv. campestris that is necessary for lipopolysaccharide production encodes a set of enzymes involved in the synthesis of dTDP-rhamnose.

    Science.gov (United States)

    Köplin, R; Wang, G; Hötte, B; Priefer, U B; Pühler, A

    1993-12-01

    By mutational analysis it was found that a 3.9-kb SmaI-XhoII DNA fragment of Xanthomonas campestris pv. campestris is involved in lipopolysaccharide (LPS) biosynthesis. LPS samples isolated from different mutants carrying mutations in the 3.9-kb SmaI-XhoII DNA fragment exhibited banding patterns in silver-stained sodium dodecyl sulfate-polyacrylamide gels markedly different from that of the wild-type LPS. Moreover, comparison of the monosaccharide composition obtained by high-performance anion-exchange chromatography with pulsed amperometric detection of LPS purified from wild-type Xanthomonas campestris pv. campestris B100 and from mutants with mutations in the 3.9-kb SmaI-XhoII DNA fragment revealed a lack of rhamnose moieties in the mutant LPS. Sequence analysis of this DNA fragment revealed four open reading frames (ORFs), designated ORF302, ORF183, ORF295, and ORF351. The deduced amino acid sequences of these ORFs showed a high degree of homology to the deduced amino acid sequences of the rfbC, rfbD, rfbA, and rfbB genes of Salmonella typhimurium LT2, which have been shown to encode a set of enzymes responsible for conversion of glucose 1-phosphate to dTDP-rhamnose.

  6. PECTATE LYASE-LIKE10 is associated with pollen wall development in Brassica campestris.

    Science.gov (United States)

    Jiang, Jingjing; Yao, Lina; Yu, Youjian; Lv, Meiling; Miao, Ying; Cao, Jiashu

    2014-11-01

    PECTATE LYASE-LIKE10 (PLL10) was previously identified as one of the differentially expressed genes both in microspores during the late pollen developmental stages and in pistils during the fertilization process in Chinese cabbage (Brassica campestris ssp. chinensis). Here, antisense-RNA was used to study the functions of BcPLL10 in Chinese cabbage. Abnormal pollen was identified in the transgenic lines (bcpll10-4, -5, and -6). In fertilization experiments, fewer seeds were harvested when the antisense-RNA lines were used as pollen donor. In vivo and in vitro pollen germination assays less germinated pollen tubes were observed in bcpll10 lines. Scanning electron microscopy observation verified that the tryphine materials were over accumulated around the pollen surface and sticked them together in bcpll10. Moreover, transmission electron microscopy observation revealed that the internal endintine was overdeveloped and predominantly occupied the intine, and disturbed the normal proportional distribution of the two layers in the non-germinal furrow region; and no obvious demarcation existed between them in the germinal furrow region in the bcpll10 pollen. Collectively, this study presented a novel PLL gene that played an important role during the pollen wall development in B. campestris, which may also possess potential importance for male sterility usage in agriculture. © 2014 Institute of Botany, Chinese Academy of Sciences.

  7. PECTATE LYASE-LIKE 9 from Brassica campestris is associated with intine formation.

    Science.gov (United States)

    Jiang, Jingjing; Yao, Lina; Yu, Youjian; Liang, Ying; Jiang, Jianxia; Ye, Nenghui; Miao, Ying; Cao, Jiashu

    2014-12-01

    Brassica campestris pectate lyase-like 9 (BcPLL9) was previously identified as a differentially expressed gene both in buds during late pollen developmental stage and in pistils during fertilization in Chinese cabbage. To characterize the gene's function, antisense-RNA lines of BcPLL9 (bcpll9) were constructed in Chinese cabbage. Self- and cross-fertilization experiments harvested half seed yields when bcpll9 lines were used as pollen donors. In vivo and in vitro pollen germination assays showed that nearly half of the pollen tubes in bcpll9 were irregular with shorter length and uneven surface. Aniline blue staining identified abnormal accumulation of a specific bright blue unknown material in the bcpll9 pollen portion. Scanning electron microscopy observation verified the abnormal outthrust material to be near the pollen germinal furrows. Transmission electron microscopy observation revealed the internal endintine layer was overdeveloped and predominantly occupied the intine. This abnormally formed intine likely induced the wavy structure and growth arrest of the pollen tube in half of the bcpll9 pollen grains, which resulted in less seed yields. Collectively, this study presented a novel PLL gene that has an important function in B. campestris intine formation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Pyranose Dehydrogenase from Agaricus campestris and Agaricus xanthoderma: Characterization and Applications in Carbohydrate Conversions

    Directory of Open Access Journals (Sweden)

    Clemens K. Peterbauer

    2013-08-01

    Full Text Available Pyranose dehydrogenase (PDH is a flavin-dependent sugar oxidoreductase that is limited to a rather small group of litter-degrading basidiomycetes. The enzyme is unable to utilize oxygen as an electron acceptor, using substituted benzoquinones and (organo metal ions instead. PDH displays a broad substrate specificity and intriguing variations in regioselectivity, depending on substrate, enzyme source and reaction conditions. In contrast to the related enzyme pyranose 2-oxidase (POx, PDHs from several sources are capable of oxidizing α- or β-1→4-linked di- and oligosaccharides, including lactose. PDH from A. xanthoderma is able to perform C-1 and C-2 oxidation, producing, in addition to lactobionic acid, 2-dehydrolactose, an intermediate for the production of lactulose, whereas PDH from A. campestris oxidizes lactose nearly exclusively at the C-1 position. In this work, we present the isolation of PDH-encoding genes from A. campestris (Ac and A. xanthoderma (Ax and a comparison of other so far isolated PDH-sequences. Secretory overexpression of both enzymes in Pichia pastoris was successful when using their native signal sequences with yields of 371 U·L−1 for AxPDH and 35 U·L−1 for AcPDH. The pure enzymes were characterized biochemically and tested for applications in carbohydrate conversion reactions of industrial relevance.

  9. Production of xanthan gum by free and immobilized cells of Xanthomonas campestris and Xanthomonas pelargonii.

    Science.gov (United States)

    Niknezhad, Seyyed Vahid; Asadollahi, Mohammad Ali; Zamani, Akram; Biria, Davoud

    2016-01-01

    Production of xanthan gum using immobilized cells of Xanthomonas campestris and Xanthomonas pelargonii grown on glucose or hydrolyzed starch as carbon sources was investigated. Calcium alginate (CA) and calcium alginate-polyvinyl alcohol-boric acid (CA-PVA) beads were used for the immobilization of cells. Xanthan titers of 8.2 and 9.2g/L were obtained for X. campestris cells immobilized in CA-PVA beads using glucose and hydrolyzed starch, respectively, whereas those for X. pelargonii were 8 and 7.9 g/L, respectively. Immobilized cells in CA-PVA beads were successfully employed in three consecutive cycles for xanthan production without any noticeable degradation of the beads whereas the CA beads were broken after the first cycle. The results of this study suggested that immobilized cells are advantageous over the free cells for xanthan production. Also it was shown that the cells immobilized in CA-PVA beads are more efficient than cells immobilized in CA beads for xanthan production. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Globalization

    DEFF Research Database (Denmark)

    Plum, Maja

    Globalization is often referred to as external to education - a state of affair facing the modern curriculum with numerous challenges. In this paper it is examined as internal to curriculum; analysed as a problematization in a Foucaultian sense. That is, as a complex of attentions, worries, ways...... of reasoning, producing curricular variables. The analysis is made through an example of early childhood curriculum in Danish Pre-school, and the way the curricular variable of the pre-school child comes into being through globalization as a problematization, carried forth by the comparative practices of PISA...

  11. State - Level Regulation's Effectiveness in Addressing Global Climate Change and Promoting Solar Energy Deployment

    Science.gov (United States)

    Peterman, Carla Joy

    Paper 1, Local Solutions to Global Problems: Climate Change Policies and Regulatory Jurisdiction, considers the efficacy of various types of environmental regulations when they are applied locally to pollutants whose damages extend beyond the jurisdiction of the local regulators. Local regulations of a global pollutant may be ineffective if producers and consumers can avoid them by transacting outside the reach of the local regulator. In many cases, this may involve the physical relocation of the economic activity, a problem often referred to as "leakage." This paper highlights another way in which local policies can be circumvented: through the shuffling of who buys from whom. The paper maintains that the problems of reshuffling are exacerbated when the options for compliance with the regulations are more flexible. Numerical analyses is presented demonstrating that several proposed policies to limit greenhouse gas emissions from the California electricity sector may have very little effect on carbon emissions if they are applied only within that state. Paper 1 concludes that although local subsidies for energy efficiency, renewable electricity, and transportation biofuels constitute attempts to pick technology winners, they may be the only mechanisms that local jurisdictions, acting alone, have at their disposal to address climate change. Paper 2, Pass-Through of Solar PV Incentives to Consumers: The Early Years of California's Solar PV Incentives, examines the pass through of incentives to California solar PV system owners. The full post-subsidy price consumers pay for solar power is a key metric of the success of solar PV incentive programs and of overall PV market performance. This study examines the early years of California's most recent wave of distributed solar PV incentives (2000-2008) to determine the pass-through of incentives. Examination of this period is both intellectually and pragmatically important due to the high level of incentives provided and

  12. Baby leaf lettuce germplasm enhancement: developing diverse populations with resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vitians

    Science.gov (United States)

    Baby leaf lettuce cultivars with resistance to bacterial leaf spot (BLS) caused by Xanthomonas campestris pv. vitians (Xcv) are needed to reduce crop losses. The objectives of this research were to assess the genetic diversity for BLS resistance in baby leaf lettuce cultivars and to select early gen...

  13. Asteraceae Artemisia campestris and Artemisia herba-alba Essential Oils Trigger Apoptosis and Cell Cycle Arrest in Leishmania infantum Promastigotes

    Science.gov (United States)

    Messaoud, Chokri; Haoues, Meriam; Neffati, Noura; Bassoumi Jamoussi, Imen; Essafi-Benkhadir, Khadija; Boussaid, Mohamed; Karoui, Habib

    2016-01-01

    We report the chemical composition and anti-Leishmania and antioxidant activity of Artemisia campestris L. and Artemisia herba-alba Asso. essential oils (EOs). Our results showed that these extracts exhibit different antioxidant activities according to the used assay. The radical scavenging effects determined by DPPH assay were of IC50 = 3.3 mg/mL and IC50 = 9.1 mg/mL for Artemisia campestris and Artemisia herba-alba essential oils, respectively. However, antioxidant effects of both essential oils, determined by ferric-reducing antioxidant power (FRAP) assay, were in the same range (2.3 and 2.97 mg eq EDTA/g EO, resp.), while the Artemisia herba-alba essential oil showed highest chelating activity of Fe2+ ions (27.48 mM Fe2+). Interestingly, we showed that both EOs possess dose-dependent activity against Leishmania infantum promastigotes with IC50 values of 68 μg/mL and 44 μg/mL for A. herba-alba and A. campestris, respectively. We reported, for the first time, that antileishmanial activity of both EOs was mediated by cell apoptosis induction and cell cycle arrest at the sub-G0/G1 phase. All our results showed that EOs from A. herba-alba and A. campestris plants are promising candidates as anti-Leishmania medicinal products. PMID:27807464

  14. Random amplified polymorphic DNA markers of the Brassica alboglabra chromosome of a B. campestris-alboglabra addition line

    DEFF Research Database (Denmark)

    Bagger Jørgensen, Rikke; Chen, B.Y.; Cheng, B.F.

    1996-01-01

    The alien C-genome chromosome in a Brassica campestris-alboglabra monosomic addition line was characterized by random amplified polymorphic DNA (RAPD) analysis. The alien chromosome carried three loci, E(c), W-c and Lap-1C, controlling synthesis of erucic acid, white flower colour and a fast...

  15. Identification of Aedes campestris from New Mexico: with notes on the isolation of western equine encephalitis and other arboviruses.

    Science.gov (United States)

    Clark, G G; Crabbs, C L; Bailey, C L; Calisher, C H; Craig, G B

    1986-12-01

    An arbovirus survey was conducted during August 1985 at White Sands Missile Range in southcentral New Mexico following a suspected arboviral disease epizootic among feral horses. A total of 20,566 mosquitoes (18,505 females and 2,061 males) and 8,900 biting gnats were collected and assayed for virus. Female mosquitoes were principally Aedes campestris (54.8%), Aedes dorsalis (30.4%) and Culex tarsalis (13.2%). Arboviruses were not isolated from biting gnats, but mosquitoes yielded a total of 37 viral isolates, including western equine encephalitis (WEE) (18), California serogroup (15), Cache Valey (1), and Hart Park (1) viruses in addition to 2, as yet unidentified, rhabdoviruses. Isolates of WEE virus were from 9 pools of Ae. campestris, 6 of Cx. tarsalis and 3 of Ae. dorsalis. California serogroup viruses, including 2 subtypes, were obtained from 7 pools of females and 1 pool of males of Ae. campestris and from 4 pools of Ae. dorsalis. Cache Valley and Hart Park viruses were isolated from single pools of Ae. dorsalis and Cx. tarsalis, respectively, and the rhabdoviruses were obtained from Ae. campestris and Psorophora signipennis.

  16. Cloning of a two-component signal transduction system of Xanthomonas campestris pv. phaseoli var. fuscans strain BXPF65

    DEFF Research Database (Denmark)

    Chan, JWYF; Maynard, Scott; Goodwin, PH

    1998-01-01

    A putative two-component signal transduction system was amplified and cloned from the plant pathogenic bacterium Xanthomonas campestris pv. phaseoli var. fuscans isolate BXPF65. The 620 bp amplified fragment was sequenced and analyzed with the BLAST Enhanced Alignment Utility (BEAUTY). BEAUTY ana...

  17. The inheritance of resistance to bacterial leaf spot of lettuce caused by Xanthomonas campestris pv. vitians in three lettuce cultivars

    Science.gov (United States)

    Lettuce yields can be reduced by the disease bacterial leaf spot (BLS) caused by the pathogen Xanthomonas campestris pv. vitians (Xcv) and host resistance is the most feasible method to reduce disease losses. The cultivars La Brillante, Pavane, and Little Gem express an incompatible host-pathogen in...

  18. Whole-Genome Re-Alignment Facilitates Development of Specific Molecular Markers for Races 1 and 4 of Xanthomonas campestris pv. campestris, the Cause of Black Rot Disease in Brassica oleracea.

    Science.gov (United States)

    Rubel, Mehede Hassan; Robin, Arif Hasan Khan; Natarajan, Sathishkumar; Vicente, Joana G; Kim, Hoy-Taek; Park, Jong-In; Nou, Ill-Sup

    2017-11-24

    Black rot, caused by Xanthomonas campestris pv. campestris (Xcc), is a seed borne disease of Brassicaceae. Eleven pathogenic races have been identified based on the phenotype interaction pattern of differential brassica cultivars inoculated with different strains. Race 1 and 4 are the two most frequent races found in Brassica oleracea crops. In this study, a PCR molecular diagnostic tool was developed for the identification of Xcc races 1 and 4 of this pathogen. Whole genomic sequences of races 1, 3, 4 and 9 and sequences of three other Xanthomonas pathovars/species (X. campestris pv. incanae (Xci), X. campestris pv. raphani (Xcr) and X.euvesicatoria (Xev) were aligned to identify variable regions among races. To develop specific markers for races 1 and 4, primers were developed from a region where sequences were dissimilar in other races. Sequence-characterized amplified regions (SCAR) and insertion or deletion of bases (InDel) were used to develop each specific set of primers. The specificity of the selected primers was confirmed by PCR tests using genomic DNA of seven different Xcc races, two strains of X. campestris pathovars and other species of bacteria. Bacterial samples of the races 1 and 4 isolates were collected from artificially inoculated cabbage leaves to conduct bio-PCR. Bio-PCR successfully detected the two Xcc isolates. By using our race-specific markers, a potential race 1 strain from the existing Korean Xcc collection was identified. The Xcc race 1 and 4-specific markers developed in this study are novel and can potentially be used for rapid detection of Xcc races through PCR.

  19. Whole-Genome Re-Alignment Facilitates Development of Specific Molecular Markers for Races 1 and 4 of Xanthomonas campestris pv. campestris, the Cause of Black Rot Disease in Brassica oleracea

    Directory of Open Access Journals (Sweden)

    Mehede Hassan Rubel

    2017-11-01

    Full Text Available Black rot, caused by Xanthomonas campestris pv. campestris (Xcc, is a seed borne disease of Brassicaceae. Eleven pathogenic races have been identified based on the phenotype interaction pattern of differential brassica cultivars inoculated with different strains. Race 1 and 4 are the two most frequent races found in Brassica oleracea crops. In this study, a PCR molecular diagnostic tool was developed for the identification of Xcc races 1 and 4 of this pathogen. Whole genomic sequences of races 1, 3, 4 and 9 and sequences of three other Xanthomonas pathovars/species (X. campestris pv. incanae (Xci, X. campestris pv. raphani (Xcr and X. euvesicatoria (Xev were aligned to identify variable regions among races. To develop specific markers for races 1 and 4, primers were developed from a region where sequences were dissimilar in other races. Sequence-characterized amplified regions (SCAR and insertion or deletion of bases (InDel were used to develop each specific set of primers. The specificity of the selected primers was confirmed by PCR tests using genomic DNA of seven different Xcc races, two strains of X. campestris pathovars and other species of bacteria. Bacterial samples of the races 1 and 4 isolates were collected from artificially inoculated cabbage leaves to conduct bio-PCR. Bio-PCR successfully detected the two Xcc isolates. By using our race-specific markers, a potential race 1 strain from the existing Korean Xcc collection was identified. The Xcc race 1 and 4-specific markers developed in this study are novel and can potentially be used for rapid detection of Xcc races through PCR.

  20. Reconstruction of the yeast Snf1 kinase regulatory network reveals its role as a global energy regulator

    DEFF Research Database (Denmark)

    Usaite, Renata; Jewett, Michael Christopher; Soberano de Oliveira, Ana Paula

    2009-01-01

    Highly conserved among eukaryotic cells, the AMP-activated kinase (AMPK) is a central regulator of carbon metabolism. To map the complete network of interactions around AMPK in yeast (Snf1) and to evaluate the role of its regulatory subunit Snf4, we measured global mRNA, protein and metabolite le...... findings showed that Snf1 is a low-energy checkpoint and that yeast can be used more extensively as a model system for studying the molecular mechanisms underlying the global regulation of AMPK in mammals, failure of which leads to metabolic diseases.......Highly conserved among eukaryotic cells, the AMP-activated kinase (AMPK) is a central regulator of carbon metabolism. To map the complete network of interactions around AMPK in yeast (Snf1) and to evaluate the role of its regulatory subunit Snf4, we measured global mRNA, protein and metabolite...... identified Snf1's global regulation on gene and protein expression levels, and showed that yeast Snf1 has a far more extensive function in controlling energy metabolism than reported earlier. Additionally, we identified complementary roles of Snf1 and Snf4. Similar to the function of AMPK in humans, our...

  1. Global aspects of pacC regulation of pathogenicity genes in Colletotrichum gloeosporioides as revealed by transcriptome analysis.

    Science.gov (United States)

    Alkan, Noam; Meng, Xiangchun; Friedlander, Gilgi; Reuveni, Eli; Sukno, Serenella; Sherman, Amir; Thon, Michael; Fluhr, Robert; Prusky, Dov

    2013-11-01

    Colletotrichum gloeosporioides alkalinizes its surroundings during colonization of host tissue. The transcription factor pacC is a regulator of pH-controlled genes and is essential for successful colonization. We present here the sequence assembly of the Colletotrichum fruit pathogen and use it to explore the global regulation of pathogenicity by ambient pH. The assembled genome size was 54 Mb, encoding 18,456 genes. Transcriptomes of the wild type and ΔpacC mutant were established by RNA-seq and explored for their global pH-dependent gene regulation. The analysis showed that pacC upregulates 478 genes and downregulates 483 genes, comprising 5% of the fungal genome, including transporters, antioxidants, and cell-wall-degrading enzymes. Interestingly, gene families with similar functionality are both up- and downregulated by pacC. Global analysis of secreted genes showed significant pacC activation of degradative enzymes at alkaline pH and during fruit infection. Select genes from alkalizing-type pathogen C. gloeosporioides and from acidifying-type pathogen Sclerotinia sclerotiorum were verified by quantitative reverse-transcription polymerase chain reaction analysis at different pH values. Knock out of several pacC-activated genes confirmed their involvement in pathogenic colonization of alkalinized surroundings. The results suggest a global regulation by pacC of key pathogenicity genes during pH change in alkalinizing and acidifying pathogens.

  2. Global phosphoproteomic analysis of human skeletal muscle reveals a network of exercise-regulated kinases and AMPK substrates

    DEFF Research Database (Denmark)

    Hoffman, Nolan J; Parker, Benjamin L; Chaudhuri, Rima

    2015-01-01

    Exercise is essential in regulating energy metabolism and whole-body insulin sensitivity. To explore the exercise signaling network, we undertook a global analysis of protein phosphorylation in human skeletal muscle biopsies from untrained healthy males before and after a single high...

  3. Structural and functional characterization of Pseudomonas aeruginosa global regulator AmpR.

    Science.gov (United States)

    Caille, Olivier; Zincke, Diansy; Merighi, Massimo; Balasubramanian, Deepak; Kumari, Hansi; Kong, Kok-Fai; Silva-Herzog, Eugenia; Narasimhan, Giri; Schneper, Lisa; Lory, Stephen; Mathee, Kalai

    2014-11-01

    Pseudomonas aeruginosa is a dreaded pathogen in many clinical settings. Its inherent and acquired antibiotic resistance thwarts therapy. In particular, derepression of the AmpC β-lactamase is a common mechanism of β-lactam resistance among clinical isolates. The inducible expression of ampC is controlled by the global LysR-type transcriptional regulator (LTTR) AmpR. In the present study, we investigated the genetic and structural elements that are important for ampC induction. Specifically, the ampC (PampC) and ampR (PampR) promoters and the AmpR protein were characterized. The transcription start sites (TSSs) of the divergent transcripts were mapped using 5' rapid amplification of cDNA ends-PCR (RACE-PCR), and strong σ(54) and σ(70) consensus sequences were identified at PampR and PampC, respectively. Sigma factor RpoN was found to negatively regulate ampR expression, possibly through promoter blocking. Deletion mapping revealed that the minimal PampC extends 98 bp upstream of the TSS. Gel shifts using membrane fractions showed that AmpR binds to PampC in vitro whereas in vivo binding was demonstrated using chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR). Additionally, site-directed mutagenesis of the AmpR helix-turn-helix (HTH) motif identified residues critical for binding and function (Ser38 and Lys42) and critical for function but not binding (His39). Amino acids Gly102 and Asp135, previously implicated in the repression state of AmpR in the enterobacteria, were also shown to play a structural role in P. aeruginosa AmpR. Alkaline phosphatase fusion and shaving experiments suggest that AmpR is likely to be membrane associated. Lastly, an in vivo cross-linking study shows that AmpR dimerizes. In conclusion, a potential membrane-associated AmpR dimer regulates ampC expression by direct binding. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  4. Limpeza clonal de mudas de videira infectadas por Xanthomonas campestris pv. viticola Clonal cleaning of grapevine plants infected by Xanthomonas campestris pv. viticola

    Directory of Open Access Journals (Sweden)

    Adriano Márcio Freire Silva

    2013-03-01

    Full Text Available O cancro bacteriano da videira é causado por Xanthomonas campestris pv. viticola (Xcv. Visando à limpeza clonal de mudas de 'Red Globe', foram estudados: tamanho ideal de ápices e gemas axilares para cultivo em meio de Galzy modificado (MGM; efeito da termoterapia (38ºC/30 dias; e ação de antibióticos na eliminação de Xcv em videiras infectadas. Os percentuais de contaminação por Xcv e de regeneração foram analisados, e as plantas obtidas foram indexadas em meio ágar nutritivo-dextrose-extrato de levedura-ampicilina (NYDAM, seguindo-se teste de patogenicidade. O cultivo de explantes com 3 mm possibilitou a obtenção de plantas livres da bactéria, com regeneração 14,3 vezes maior que explantes com 1 mm. A termoterapia de mudas infectadas, associada ao cultivo in vitro, não eliminou o patógeno. O cultivo de explantes com 10 mm, durante 40 dias em MGM + cefotaxima (300 mg L-1, proporcionou limpeza clonal das mudas. A indexação de plantas de videira regeneradas in vitro, quanto à infecção por Xcv utilizando NYDAM, seguida de teste de patogenicidade, é uma alternativa econômica e eficiente para produção de mudas de alta qualidade fitossanitária.Bacterial canker is caused by Xanthomonas campestris pv. viticola (Xcv. In order to eliminate Xcv from 'Red Globe' plants it was studied: optimal size of meristem tips and axillary buds for cultivation in modified Galzy's medium (MGM; effects of thermotherapy (38ºC/30 days; and action of antibiotics in the elimination of Xcv in infected grapevines. The percentages of contamination by Xcv and regeneration were analyzed and plants obtained were indexed using the semi-selective culture medium nutrient agar-dextrose-yeast extract-ampicilin (NYDAM followed by a pathogenicity test. The cultivation of 3 mm explants permitted to obtain plants free of bacteria with regeneration 14.3 times higher than 1 mm explants. The thermotherapy of infected plants associated to the in vitro culture

  5. Development of immunofluorescence colony staining (IFC) for detection of Xanthomonas campestris pv. vesicatoria and Clavibacter michiganensis subsp michiganensis in tomato seeds

    NARCIS (Netherlands)

    Nemeth, J.; Vuurde, van J.W.L.

    2006-01-01

    Immunofluorescence colony-staining (IFC) is based on sample pour plating in combination with immunofluorescence staining for recognition of the target colony. IFC was optimised for detecting Xanthomonas campestris pv. vesicatoria (Xcv) and Clavibacter michiganensis subsp. michiganensis (Cmm) in

  6. IVF policy and global/local politics: the making of multiple-embryo transfer regulation in Taiwan.

    Science.gov (United States)

    Wu, Chia-Ling

    2012-08-01

    This paper analyzes the regulatory trajectory of multiple-embryo transfer in in-vitro fertilization (IVF) in Taiwan. Taking a latecomer to policy-making as the case, it argues the importance of conceptualizing the global/local dynamics in policy-making for assisted reproductive technology (ART). The conceptual framework is built upon recent literature on standardization, science policy, and global assemblage. I propose three interrelated features that reveal the "global in the local": (1) the power relationships among stakeholders, (2) the selected global form that involved actors drew upon, and (3) the re-contextualized assemblage made of local networks. Data included archives, interviews, and participant observation. In different historical periods the specific stakeholders selected different preferred global forms for Taiwan, such as Britain's code of ethics in the 1990s, the American guideline in the early 2000s, and the European trend in the mid-2000s. The global is heterogeneous. The failure to transfer the British regulation, the revision of the American guideline by adding one more embryo than it specified, and the gap between the cited European trend and the "no more than four" in Taiwan's 2007 Human Reproduction Law all show that the local network further transforms the selected global form, confining it to rhetoric only or tailoring it to local needs. Overall, Taiwanese practitioners successfully maintained their medical autonomy to build a 'flexible standardization'. Multiple pregnancy remains the most common health risk of IVF in Taiwan. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Molecular evolution of virulence in natural field strains of Xanthomonas campestris pv. vesicatoria.

    Science.gov (United States)

    Gassmann, W; Dahlbeck, D; Chesnokova, O; Minsavage, G V; Jones, J B; Staskawicz, B J

    2000-12-01

    The avrBs2 avirulence gene of the bacterial plant pathogen Xanthomonas campestris pv. vesicatoria triggers disease resistance in pepper plants containing the Bs2 resistance gene and contributes to bacterial virulence on susceptible host plants. We studied the effects of the pepper Bs2 gene on the evolution of avrBs2 by characterizing the molecular basis for virulence of 20 X. campestris pv. vesicatoria field strains that were isolated from disease spots on previously resistant Bs2 pepper plants. All field strains tested were complemented by a wild-type copy of avrBs2 in their ability to trigger disease resistance on Bs2 plants. DNA sequencing revealed four mutant alleles of avrBs2, two of which consisted of insertions or deletions of 5 nucleotides in a repetitive region of avrBs2. The other two avrBs2 alleles were characterized by point mutations with resulting single amino acid changes (R403P or A410D). We generated isogenic X. campestris pv. vesicatoria strains by chromosomal avrBs2 gene exchange to study the effects of these mutations on the dual functions of avrBs2 in enhancing bacterial virulence and inducing plant resistance by in planta bacterial growth experiments. The deletion of 5 nucleotides led to loss of avrBs2-induced resistance on Bs2 pepper plants and abolition of avrBs2-mediated enhancement of fitness on susceptible plants. Significantly, the point mutations led to minimal reduction in virulence function of avrBs2 on susceptible pepper plants, with either minimal (R403P allele) or an intermediate level of (A410D allele) triggering of resistance on Bs2 plants. Consistent with the divergent selection pressures on avrBs2 exerted by the Bs2 resistance gene, our results show that avrBs2 is evolving to decrease detection by the Bs2 gene while at the same time maintaining its virulence function.

  8. Reconstruction of the yeast Snf1 kinase regulatory network reveals its role as a global energy regulator

    Science.gov (United States)

    Usaite, Renata; Jewett, Michael C; Oliveira, Ana Paula; Yates, John R; Olsson, Lisbeth; Nielsen, Jens

    2009-01-01

    Highly conserved among eukaryotic cells, the AMP-activated kinase (AMPK) is a central regulator of carbon metabolism. To map the complete network of interactions around AMPK in yeast (Snf1) and to evaluate the role of its regulatory subunit Snf4, we measured global mRNA, protein and metabolite levels in wild type, Δsnf1, Δsnf4, and Δsnf1Δsnf4 knockout strains. Using four newly developed computational tools, including novel DOGMA sub-network analysis, we showed the benefits of three-level ome-data integration to uncover the global Snf1 kinase role in yeast. We for the first time identified Snf1's global regulation on gene and protein expression levels, and showed that yeast Snf1 has a far more extensive function in controlling energy metabolism than reported earlier. Additionally, we identified complementary roles of Snf1 and Snf4. Similar to the function of AMPK in humans, our findings showed that Snf1 is a low-energy checkpoint and that yeast can be used more extensively as a model system for studying the molecular mechanisms underlying the global regulation of AMPK in mammals, failure of which leads to metabolic diseases. PMID:19888214

  9. A Surfactant-Induced Functional Modulation of a Global Virulence Regulator from Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Sukhendu Mandal

    Full Text Available Triton X-100 (TX-100, a useful non-ionic surfactant, reduced the methicillin resistance in Staphylococcus aureus significantly. Many S. aureus proteins were expressed in the presence of TX-100. SarA, one of the TX-100-induced proteins, acts as a global virulence regulator in S. aureus. To understand the effects of TX-100 on the structure, and function of SarA, a recombinant S. aureus SarA (rSarA and its derivative (C9W have been investigated in the presence of varying concentrations of this surfactant using various probes. Our data have revealed that both rSarA and C9W bind to the cognate DNA with nearly similar affinity in the absence of TX-100. Interestingly, their DNA binding activities have been significantly increased in the presence of pre-micellar concentration of TX-100. The increase of TX-100 concentrations to micellar or post-micellar concentration did not greatly enhance their activities further. TX-100 molecules have altered the secondary and tertiary structures of both proteins to some extents. Size of the rSarA-TX-100 complex appears to be intermediate to those of rSarA and TX-100. Additional analyses show a relatively moderate interaction between C9W and TX-100. Binding of TX-100 to C9W has, however, occurred by a cooperative pathway particularly at micellar and higher concentrations of this surfactant. Taken together, TX-100-induced structural alteration of rSarA and C9W might be responsible for their increased DNA binding activity. As TX-100 has stabilized the somewhat weaker SarA-DNA complex effectively, it could be used to study its structure in the future.

  10. The United Nations and One Health: the International Health Regulations (2005) and global health security.

    Science.gov (United States)

    Nuttall, I; Miyagishima, K; Roth, C; de La Rocque, S

    2014-08-01

    The One Health approach encompasses multiple themes and can be understood from many different perspectives. This paper expresses the viewpoint of those in charge of responding to public health events of international concern and, in particular, to outbreaks of zoonotic disease. Several international organisations are involved in responding to such outbreaks, including the United Nations (UN) and its technical agencies; principally, the Food and Agriculture Organization of the UN (FAO) and the World Health Organization (WHO); UN funds and programmes, such as the United Nations Development Programme, the World Food Programme, the United Nations Environment Programme, the United Nations Children's Fund; the UN-linked multilateral banking system (the World Bank and regional development banks); and partner organisations, such as the World Organisation for Animal Health (OIE). All of these organisations have benefited from the experiences gained during zoonotic disease outbreaks over the last decade, developing common approaches and mechanisms to foster good governance, promote policies that cut across different sectors, target investment more effectively and strengthen global and national capacities for dealing with emerging crises. Coordination among the various UN agencies and creating partnerships with related organisations have helped to improve disease surveillance in all countries, enabling more efficient detection of disease outbreaks and a faster response, greater transparency and stakeholder engagement and improved public health. The need to build more robust national public human and animal health systems, which are based on good governance and comply with the International Health Regulations (2005) and the international standards set by the OIE, prompted FAO, WHO and the OIE to join forces with the World Bank, to provide practical tools to help countries manage their zoonotic disease risks and develop adequate resources to prevent and control disease

  11. Effects of foliar dressing of selenite and silicate alone or combined with different soil ameliorants on the accumulation of As and Cd and antioxidant system in Brassica campestris.

    Science.gov (United States)

    Ding, Yongzhen; Wang, Yongjiu; Zheng, Xiangqun; Cheng, Weimin; Shi, Rongguang; Feng, Renwei

    2017-08-01

    This study was conducted to investigate the possibility of using a combined technology to synchronously reduce As and Cd accumulation in the edible parts of Brassica campestris. The results showed that a foliar application of selenite (Se) and silicon (Si) combined with soil ameliorants (including Ca-Mg-P fertilizer, sodium silicate and red mud) showed limited effects on the growth of B. campestris. The As concentration in the leaves of B. campestris in all treatments was below the Chinese safety standard. When sodium silicate and Ca-Mg-P fertilizer were added to the soil, the additional foliar application of Se and Si could in some cases help further reduce the concentrations of As and Cd in the leaves of B. campestris. However, when red mud was applied to the soil, the foliar application of Se and Si enhanced the Cd concentration in the leaves of B. campestris. In most cases, high levels of soil ameliorants plus foliar application of Se and Si significantly enhanced the As concentrations in both the soil solution and the roots of B. campestris but reduced the soil solution Cd concentration and the leaf As concentration. Most of the treatments reduced the thiobarbituric acid reactive substances (TBARS) concentration in the leaves of B. campestris, and the foliar application of Se and Si helped the soil ameliorants alleviate the oxidative stress resulting from As and Cd exposure. In this study, several treatments significantly increased the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). However, the enzymes peroxidase (POD) and catalase (CAT) were not induced by most treatments. In summary, the combined treatment of 1gkg-1 Ca-Mg-P fertilizer plus foliar spraying 2mmolL-1 sodium selenite was most effective in reducing the Cd concentration and a rather strong ability to reduce the As concentration and trigger the activities of SOD and APX in the leaves of B. campestris. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Detection and identification of phytopathogenic Xanthomonas strains by amplification of DNA sequences related to the hrp genes of Xanthomonas campestris pv. vesicatoria.

    OpenAIRE

    Leite, R P; Minsavage, G. V.; Bonas, U; Stall, R. E.

    1994-01-01

    Three pairs of oligonucleotide primers specific for different regions of the hrp gene (hypersensitive reaction and pathogenicity) cluster of Xanthomonas campestris pv. vesicatoria were designed and tested for amplification of DNA isolated from a large number of different bacteria. DNA sequences related to the hrp genes were successfully amplified from X. fragariae and from 28 pathovars of X. campestris. No DNA amplification occurred with genomic DNA from phytopathogenic strains of X. campestr...

  13. Sensitive and specific detection of Xanthomonas campestris pv. pelargonii with DNA primers and probes identified by random amplified polymorphic DNA analysis.

    OpenAIRE

    Manulis, S; Valinsky, L; Lichter, A; Gabriel, D. W.

    1994-01-01

    The random amplified polymorphic DNA method was used to distinguish strains of Xanthomonas campestris pv. pelargonii from 21 other Xanthomonas species and/or pathovars. Among the 42 arbitrarily chosen primers evaluated, 3 were found to reveal diagnostic polymorphisms when purified DNAs from compared strains were amplified by the PCR. The three primers revealed DNA amplification patterns which were conserved among all 53 strains tested of X. campestris pv. pelargonii isolated from various loca...

  14. Proactive Selective Inhibition Targeted at the Neck Muscles: This Proximal Constraint Facilitates Learning and Regulates Global Control.

    Science.gov (United States)

    Loram, Ian D; Bate, Brian; Harding, Pete; Cunningham, Ryan; Loram, Alison

    2017-04-01

    While individual muscle function is known, the sensory and motor value of muscles within the whole-body sensorimotor network is complicated. Specifically, the relationship between neck muscle action and distal muscle synergies is unknown. This work demonstrates a causal relationship between regulation of the neck muscles and global motor control. Studying violinists performing unskilled and skilled manual tasks, we provided ultrasound feedback of the neck muscles with instruction to minimize neck muscle change during task performance and observed the indirect effect on whole-body movement. Analysis of ultrasound, kinematic, electromyographic and electrodermal recordings showed that proactive inhibition targeted at neck muscles had an indirect global effect reducing the cost of movement, reducing complex involuntary, task-irrelevant movement patterns and improving balance. This effect was distinct from the effect of gaze alignment which increased physiological cost and reduced laboratory-referenced movement. Neck muscle inhibition imposes a proximal constraint on the global motor plan, forcing a change in highly automated sensorimotor control. The proximal location ensures global influence. The criterion, inhibition of unnecessary action, ensures reduced cost while facilitating task-relevant variation. This mechanism regulates global motor function and facilitates reinforcement learning to change engrained, maladapted sensorimotor control associated with chronic pain, injury and performance limitation.

  15. Global analyses of TetR family transcriptional regulators in mycobacteria indicates conservation across species and diversity in regulated functions.

    Science.gov (United States)

    Balhana, Ricardo J C; Singla, Ashima; Sikder, Mahmudul Hasan; Withers, Mike; Kendall, Sharon L

    2015-06-27

    Mycobacteria inhabit diverse niches and display high metabolic versatility. They can colonise both humans and animals and are also able to survive in the environment. In order to succeed, response to environmental cues via transcriptional regulation is required. In this study we focused on the TetR family of transcriptional regulators (TFTRs) in mycobacteria. We used InterPro to classify the entire complement of transcriptional regulators in 10 mycobacterial species and these analyses showed that TFTRs are the most abundant family of regulators in all species. We identified those TFTRs that are conserved across all species analysed and those that are unique to the pathogens included in the analysis. We examined genomic contexts of 663 of the conserved TFTRs and observed that the majority of TFTRs are separated by 200 bp or less from divergently oriented genes. Analyses of divergent genes indicated that the TFTRs control diverse biochemical functions not limited to efflux pumps. TFTRs typically bind to palindromic motifs and we identified 11 highly significant novel motifs in the upstream regions of divergently oriented TFTRs. The C-terminal ligand binding domain from the TFTR complement in M. tuberculosis showed great diversity in amino acid sequence but with an overall architecture common to other TFTRs. This study suggests that mycobacteria depend on TFTRs for the transcriptional control of a number of metabolic functions yet the physiological role of the majority of these regulators remain unknown.

  16. Caracterização de isolados de Xanthomonas campestris pv campestris de sistemas de produção orgânico e reação de brássicas à podridão-negra Characterization of strains of Xanthomonas campestris pv campestris from organic farming systems and reaction of brassicas to black rot

    Directory of Open Access Journals (Sweden)

    Liliana Andréa dos Santos

    2008-12-01

    Full Text Available Noventa isolados de Xanthomonas campestris pv. campestris (Xcc de brássicas oriundas de sistemas de produção orgânico das Zonas da Mata e Agreste de Pernambuco foram caracterizados com base na sensibilidade a antibióticos e sulfato de cobre e atividade de esterase. A maioria apresentou alta sensibilidade à tetraciclina (76,6%, eritromicina (63,3% e estreptomicina (63,3%, resistência à amoxicilina (70%, gentamicina (40,0% e norfloxacin (45,5% e média sensibilidade (44,4% ou resistência (44,4% à neomicina. Cinqüenta e cinco isolados de Xcc foram resistentes ao sulfato de cobre na concentração de 50 mg/mL e todos foram sensíveis ao produto na concentração de 200 mg/mL. Atividade de esterase foi apresentada por 92,22% dos isolados. A análise Euclidiana por ligação simples evidenciou variabilidade entre os isolados separando-os em sete grupos de similaridade. Foi estudada também a reação de 14 cultivares de brássicas à podridão-negra, utilizando o isolado "B21" de Xcc. As cultivares diferiram significativamente entre si em relação ao período de incubação, incidência e severidade final da doença. Os maiores valores de severidade final da doença foram verificados em brócolos "Ramoso", couve-flor "Bola de Neve" e "Piracicaba de Verão", e repolho "Chato de Quintal". Os híbridos de couve-chinesa "AF 70", "AF 72", "AF 69" e "AF 66" mostraram-se altamente resistentes à doença, enquanto que brócolos "Ramoso" e "Precoce Piracicaba", couve-flor "Piracicaba de Verão" e "Híbrido Cindy" e repolho "60 Dias" foram medianamente resistentes.Ninety strains of Xanthomonas campestris pv. campestris (Xcc from brassicas grown under organic farming systems in the "Mata" and "Agreste" regions of Pernambuco, Brazil, were characterized based upon sensitivity to antibiotics and copper sulfate, and esterase activity. Most of the strains showed high sensitivity to tetracycline (76.6%, erythromycin (63.3% and streptomycin (63

  17. Expression, purification and crystallization of the outer membrane lipoprotein GumB from Xanthomonas campestris.

    Science.gov (United States)

    Jacobs, Melisa; Salinas, Silvina R; Bianco, María I; Ielpi, Luis

    2012-10-01

    GumB is a predicted outer membrane lipoprotein that is involved in the synthesis and/or secretion of xanthan gum. This exopolysaccharide, produced by Xanthomonas campestris, is valuable in industry because of its important rheological properties. Solution of the GumB structure will provide insight into the polymerization and/or secretion mechanisms of xanthan gum. GumB was overexpressed and purified and diffraction-quality crystals of native GumB were obtained. A complete data set was collected to 2.54 Å resolution with an R(p.i.m.) of 0.034. The crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 84.4, b = 90.5, c = 120.7 Å.

  18. Regulation and Supervision of The Global Financial System. A Proposal for Institutional Reform

    NARCIS (Netherlands)

    Denters, H.M.G.

    2009-01-01

    nternational financial markets are supervised primarily by national authorities. However, national authorities are inherently incapable to regulate and supervise seamless globalised financial markets. To the extent international regulators exist, they constitute a disorderly patchwork of

  19. Regulators of coastal wetland methane production and responses to simulated global change

    Science.gov (United States)

    Carmella Vizza; William E. West; Stuart E. Jones; Julia A. Hart; Gary A. Lamberti

    2017-01-01

    Wetlands are the largest natural source of methane (CH4) emissions to the atmosphere, which vary along salinity and productivity gradients. Global change has the potential to reshape these gradients and therefore alter future contributions of wetlands to the global CH4 budget. Our study examined CH4...

  20. The Effect of Field Dodder (Cuscuta campestris Yunck. on Morphological and Fluorescence Parameters of Giant Ragweed (Ambrosia trifida L.

    Directory of Open Access Journals (Sweden)

    Sava Vrbničanin

    2013-01-01

    Full Text Available The effect of the parasitic flowering plant known as field dodder (Cuscuta campestrisYunck. on morphological and fluorescence parameters of infested giant ragweed(Ambrosia trifida L. plants was examined under controlled conditions. The parameters ofchlorophyll fluorescence (Fo, Fv/Fm, ΦPSII, Fv, Fm, ETR and IF were measured on infested (Iand non-infested (N A. trifida plants over a period of seven days, beginning with the day ofinfestation. Morphological parameters (plant height, dry and fresh weight were measuredon the last day of fluorescence measurements. C. campestris was found to affect the height,fresh and dry weight of the infested A. trifida plants, causing significant reduction in plantheight and dry weight. Field dodder also affected several parameters of chlorophyll fluorescence(Fo, Fv/Fm, ΦPSII and Fv in infested A. trifida plants.

  1. Global transcriptional regulation by H-NS and its biological influence on the virulence of Enterohemorrhagic Escherichia coli.

    Science.gov (United States)

    Wan, Baoshan; Zhang, Qiufen; Tao, Jing; Zhou, Aiping; Yao, Yu-Feng; Ni, Jinjing

    2016-08-22

    As a global transcriptional regulator, H-NS, the histone-like nucleoid-associated DNA-binding and bridging protein, plays a wide range of biological roles in bacteria. In order to determine the role of H-NS in regulating gene transcription and further find out the biological significance of this protein in Enterohemorrhagic Escherichia coli (EHEC), we conducted transcriptome analysis of hns mutant by RNA sequencing. A total of 983 genes were identified to be regulated by H-NS in EHEC. 213 and 770 genes were down-regulated and up-regulated in the deletion mutant of hns, respectively. Interestingly, 34 of 97 genes on virulence plasmid pO157 were down-regulated by H-NS. Although the deletion mutant of hns showed a decreased survival rate in macrophage compared with the wild type strain, it exhibited the higher ability to colonize mice gut and became more virulent to BALB/c mice. The BALB/c mice infected with the deletion mutant of hns showed a lower survival rate, and a higher bacterial burden in the gut, compared with those infected with wild type strain, especially when the gut microbiota was not disturbed by antibiotic administration. These findings suggest that H-NS plays an important role in virulence of EHEC by interacting with host gut microbiota. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. International Maritime Transport Sector Regulation Systems and their Impact on World Shipping and Global Trade

    Directory of Open Access Journals (Sweden)

    Andrzej Grzelakowski

    2013-09-01

    Full Text Available The main purpose of the paper is to analyze the impact of two nowadays existing global regulatory systems of the world maritime transport sector on international shipping industry and global trade development. The author has focused on the characterization of the autonomous regulatory system represented in this sector by freight market with typical for it mechanism as well as on public regulatory system expressed in form of the existing international regulatory scheme introduced by IMO and other international organizations. Both regulatory mechanisms has been analyzed and viewed in terms of efficiency and effectiveness of their influence upon shipping industry and global commodity markets. At the end, the results of functioning of both regulatory subsystems have been assessed with the aim to indicate how they are able to create growth potential for the world maritime transport and trade sector as well as the global economy.

  3. Enhancing E. coli tolerance towards oxidative stress via engineering its global regulator cAMP receptor protein (CRP.

    Directory of Open Access Journals (Sweden)

    Souvik Basak

    Full Text Available Oxidative damage to microbial hosts often occurs under stressful conditions during bioprocessing. Classical strain engineering approaches are usually both time-consuming and labor intensive. Here, we aim to improve E. coli performance under oxidative stress via engineering its global regulator cAMP receptor protein (CRP, which can directly or indirectly regulate redox-sensing regulators SoxR and OxyR, and other ~400 genes in E. coli. Error-prone PCR technique was employed to introduce modifications to CRP, and three mutants (OM1~OM3 were identified with improved tolerance via H(2O(2 enrichment selection. The best mutant OM3 could grow in 12 mM H(2O(2 with the growth rate of 0.6 h(-1, whereas the growth of wild type was completely inhibited at this H(2O(2 concentration. OM3 also elicited enhanced thermotolerance at 48°C as well as resistance against cumene hydroperoxide. The investigation about intracellular reactive oxygen species (ROS, which determines cell viability, indicated that the accumulation of ROS in OM3 was always lower than in WT with or without H(2O(2 treatment. Genome-wide DNA microarray analysis has shown not only CRP-regulated genes have demonstrated great transcriptional level changes (up to 8.9-fold, but also RpoS- and OxyR-regulated genes (up to 7.7-fold. qRT-PCR data and enzyme activity assay suggested that catalase (katE could be a major antioxidant enzyme in OM3 instead of alkyl hydroperoxide reductase or superoxide dismutase. To our knowledge, this is the first work on improving E. coli oxidative stress resistance by reframing its transcription machinery through its native global regulator. The positive outcome of this approach may suggest that engineering CRP can be successfully implemented as an efficient strain engineering alternative for E. coli.

  4. Fis is a global regulator critical for modulation of virulence factor production and pathogenicity of Dickeya zeae.

    Science.gov (United States)

    Lv, Mingfa; Chen, Yufan; Liao, Lisheng; Liang, Zhibin; Shi, Zurong; Tang, Yingxin; Ye, Sixuan; Zhou, Jianuan; Zhang, Lianhui

    2018-01-10

    Dickeya zeae is the causal agent of rice foot rot disease, which has recently become a great threat to rice planting countries and regions. The pathogen produces a family of phytotoxins named zeamines that is critical for bacterial virulence, but little is known about the signaling pathways and regulatory mechanisms that govern zeamine production. In this study, we showed that a conserved transcriptional regulator Fis is involved in the regulation of zeamine production in D. zeae strain EC1. Deletion mutants were markedly attenuated in the virulence against rice seed germination. Transcriptome and phenotype analyses showed that Fis is a potent global transcriptional regulator modulating various virulence traits, including production of extracellular enzymes and exopolysaccharides, swimming and swarming motility, biofilm formation and cell aggregation. DNA gel retardation analysis showed that Fis directly regulates the transcription of key virulence genes and the genes encoding Vfm quorum sensing system through DNA/protein interaction. Our findings unveil a key regulator associated with the virulence of D. zeae EC1, and present useful clues for further elucidation of the regulatory complex and signaling pathways which govern the virulence of this important pathogen.

  5. Global mRNA sequencing of human skeletal muscle: Search for novel exercise-regulated myokines

    Directory of Open Access Journals (Sweden)

    S. Pourteymour

    2017-04-01

    Conclusion: We identified 17 new, exercise-responsive transcripts encoding secretory proteins. We further identified CSF1 as a novel myokine, which is secreted from cultured muscle cells and up-regulated in muscle and plasma after acute exercise.

  6. Global self-esteem, goal achievement orientations, and self-determined behavioural regulations in a physical education setting.

    Science.gov (United States)

    Hein, Vello; Hagger, Martin S

    2007-01-15

    We examined a theoretical model of global self-esteem that incorporated constructs from achievement goal and self-determination theories. The model hypothesized that self-determined or autonomous motives would mediate the influence of achievement goal orientation on global self-esteem. The adapted version of the Behavioural Regulation in Exercise Questionnaire (Mullan et al., 1997), the Perception of Success Questionnaire (Roberts & Balague, 1991), and Rosenberg's (1965) self-esteem scales were administered to 634 high school students aged 11 - 15 years. A structural equation model supported the hypotheses and demonstrated that autonomous motives mediated the effect of goal orientations on global self-esteem. The results suggest that generalized motivational orientations influence self-esteem by affecting autonomous motivation and is consistent with theory that suggests that experiences relating to intrinsic motivation are the mechanism by which global motivational orientations are translated into adaptive outcomes like self-esteem. The findings suggest that physical activity interventions that target autonomous motives in physical activity contexts are likely to enhance young people's general self-esteem.

  7. The Global Acetylome of the Human Pathogen Vibrio cholerae V52 Reveals Lysine Acetylation of Major Transcriptional Regulators

    DEFF Research Database (Denmark)

    Jers, Carsten; Ravikumar, Vaishnavi; Lezyk, Mateusz Jakub

    2018-01-01

    involved in metabolic and cellular processes and there was an over-representation of acetylated proteins involved in protein synthesis. Of interest, we demonstrated that many global transcription factors such as CRP, H-NS, IHF, Lrp and RpoN as well as transcription factors AphB, TcpP, and PhoB involved......Protein lysine acetylation is recognized as an important reversible post translational modification in all domains of life. While its primary roles appear to reside in metabolic processes, lysine acetylation has also been implicated in regulating pathogenesis in bacteria. Several global lysine...... of immuno-enrichment of acetylated peptides and high resolution mass spectrometry, we identified 3,402 acetylation sites on 1,240 proteins. Of the acetylated proteins, more than half were acetylated on two or more sites. As reported for other bacteria, we observed that many of the acetylated proteins were...

  8. A global comparative overview of the legal regulation of stem cell ...

    African Journals Online (AJOL)

    Stem cell research and its potential translation to regenerative medicine, tissue engineering and cell and gene therapy, have led to controversy and debates similar to the calls nearly 25 years ago for a ban involving recombinant DNA. Global legislative efforts in this field have been characterised by many legal, ethical and ...

  9. Regulators of coastal wetland methane production and responses to simulated global change

    Science.gov (United States)

    Vizza, Carmella; West, William E.; Jones, Stuart E.; Hart, Julia A.; Lamberti, Gary A.

    2017-01-01

    Wetlands are the largest natural source of methane (CH4) emissions to the atmosphere, which vary along salinity and productivity gradients. Global change has the potential to reshape these gradients and therefore alter future contributions of wetlands to the global CH4 budget. Our study examined CH4 production along a natural salinity gradient in fully inundated coastal Alaska wetlands. In the laboratory, we incubated natural sediments to compare CH4 production rates between non-tidal freshwater and tidal brackish wetlands, and quantified the abundances of methanogens and sulfate-reducing bacteria in these ecosystems. We also simulated seawater intrusion and enhanced organic matter availability, which we predicted would have contrasting effects on coastal wetland CH4 production. Tidal brackish wetlands produced less CH4 than non-tidal freshwater wetlands probably due to high sulfate availability and generally higher abundances of sulfate-reducing bacteria, whereas non-tidal freshwater wetlands had significantly greater methanogen abundances. Seawater addition experiments with freshwater sediments, however, did not reduce CH4 production, perhaps because the 14-day incubation period was too short to elicit a shift in microbial communities. In contrast, increased organic matter enhanced CH4 production in 75 % of the incubations, but this response depended on the macrophyte species added, with half of the species treatments having no significant effect. Our study suggests that CH4 production in coastal wetlands, and therefore their overall contribution to the global CH4 cycle, will be sensitive to increased organic matter availability and potentially seawater intrusion. To better predict future wetland contributions to the global CH4 budget, future studies and modeling efforts should investigate how multiple global change mechanisms will interact to impact CH4 dynamics.

  10. Genetic mapping and functional analysis of the tomato Bs4 locus governing recognition of the Xanthomonas campestris pv. vesicatoria AvrBs4 protein.

    Science.gov (United States)

    Ballvora, A; Pierre, M; van den Ackerveken, G; Schornack, S; Rossier, O; Ganal, M; Lahaye, T; Bonas, U

    2001-05-01

    Xanthomonas campestris pv. vesicatoria is the causal agent of bacterial spot disease on pepper (Capsicum spp.) and tomato (Lycopersicon spp.). Analysis of 17 different Lycopersicon accessions with avrBs4-expressing X. campestris pv. vesicatoria strains identified 15 resistant and two susceptible tomato genotypes. Genetic analysis revealed that AvrBs4 recognition in tomato is governed by a single locus, designated Bs4 (bacterial spot resistance locus no. 4). Amplified fragment length polymorphism and bulked DNA templates from resistant and susceptible plants were used to define a 2.6-cM interval containing the Bs4 locus. A standard tomato mapping population was employed to localize Bs4-linked markers on the short arm of chromosome 5. Investigation of X. campestris pv. vesicatoria hrp mutant strains revealed that AvrBs4 secretion and avirulence activity are hrp dependent. Agrobacterium-based delivery of the avrBs4 gene into tomato triggered a plant response that phenotypically resembled the hypersensitive response induced by avrBs4-expressing X. campestris pv. vesicatoria strains, suggesting symplastic perception of the avirulence protein. Mutations in the avrBs4 C-terminal nuclear localization signals (NLSs) showed that NLSs are dispensable for Bs4-mediated recognition. Our data suggest that tomato Bs4 and pepper Bs3 employ different recognition modes for detection of the highly homologous X. campestris pv. vesicatoria avirulence proteins AvrBs4 and AvrBs3.

  11. Comparative transcript profiling of fertile and sterile flower buds from multiple-allele-inherited male sterility in Chinese cabbage (Brassica campestris L. ssp. pekinensis).

    Science.gov (United States)

    Zhou, Xue; Liu, Zhiyong; Ji, Ruiqin; Feng, Hui

    2017-05-10

    We studied the underlying causes of multiple-allele-inherited male sterility in Chinese cabbage (Brassica campestris L. ssp. pekinensis) by identifying differentially expressed genes (DEGs) related to pollen sterility between fertile and sterile flower buds. In this work, we verified the stages of sterility microscopically and then performed transcriptome analysis of mRNA isolated from fertile and sterile buds using Illumina HiSeq 2000 platform sequencing. Approximately 80% of ~229 million high-quality paired-end reads were uniquely mapped to the reference genome. In sterile buds, 699 genes were significantly up-regulated and 4096 genes were down-regulated. Among the DEGs, 28 pollen cell wall-related genes, 54 transcription factor genes, 45 phytohormone-related genes, 20 anther and pollen-related genes, 212 specifically expressed transcripts, and 417 DEGs located on linkage group A07 were identified. Six transcription factor genes BrAMS, BrMS1, BrbHLH089, BrbHLH091, BrAtMYB103, and BrANAC025 were identified as putative sterility-related genes. The weak auxin signal that is regulated by BrABP1 may be one of the key factors causing pollen sterility observed here. Moreover, several significantly enriched GO terms such as "cell wall organization or biogenesis" (GO:0071554), "intrinsic to membrane" (GO:0031224), "integral to membrane" (GO:0016021), "hydrolase activity, acting on ester bonds" (GO:0016788), and one significantly enriched pathway "starch and sucrose metabolism" (ath00500) were identified in this work. qRT-PCR, PCR, and in situ hybridization experiments validated our RNA-seq transcriptome analysis as accurate and reliable. This study will lay the foundation for elucidating the molecular mechanism(s) that underly sterility and provide valuable information for studying multiple-allele-inherited male sterility in the Chinese cabbage line 'AB01'.

  12. Global transcriptome and gene regulation network for secondary metabolite biosynthesis of tea plant (Camellia sinensis).

    Science.gov (United States)

    Li, Chun-Fang; Zhu, Yan; Yu, Yao; Zhao, Qiong-Yi; Wang, Sheng-Jun; Wang, Xin-Chao; Yao, Ming-Zhe; Luo, Da; Li, Xuan; Chen, Liang; Yang, Ya-Jun

    2015-07-29

    Major secondary metabolites, including flavonoids, caffeine, and theanine, are important components of tea products and are closely related to the taste, flavor, and health benefits of tea. Secondary metabolite biosynthesis in Camellia sinensis is differentially regulated in different tissues during growth and development. Until now, little was known about the expression patterns of genes involved in secondary metabolic pathways or their regulatory mechanisms. This study aimed to generate expression profiles for C. sinensis tissues and to build a gene regulation model of the secondary metabolic pathways. RNA sequencing was performed on 13 different tissue samples from various organs and developmental stages of tea plants, including buds and leaves of different ages, stems, flowers, seeds, and roots. A total of 43.7 Gbp of raw sequencing data were generated, from which 347,827 unigenes were assembled and annotated. There were 46,693, 8446, 3814, 10,206, and 4948 unigenes specifically expressed in the buds and leaves, stems, flowers, seeds, and roots, respectively. In total, 1719 unigenes were identified as being involved in the secondary metabolic pathways in C. sinensis, and the expression patterns of the genes involved in flavonoid, caffeine, and theanine biosynthesis were characterized, revealing the dynamic nature of their regulation during plant growth and development. The possible transcription factor regulation network for the biosynthesis of flavonoid, caffeine, and theanine was built, encompassing 339 transcription factors from 35 families, namely bHLH, MYB, and NAC, among others. Remarkably, not only did the data reveal the possible critical check points in the flavonoid, caffeine, and theanine biosynthesis pathways, but also implicated the key transcription factors and related mechanisms in the regulation of secondary metabolite biosynthesis. Our study generated gene expression profiles for different tissues at different developmental stages in tea plants

  13. Promoter Analysis Reveals Globally Differential Regulation of Human Long Non-Coding RNA and Protein-Coding Genes

    KAUST Repository

    Alam, Tanvir

    2014-10-02

    Transcriptional regulation of protein-coding genes is increasingly well-understood on a global scale, yet no comparable information exists for long non-coding RNA (lncRNA) genes, which were recently recognized to be as numerous as protein-coding genes in mammalian genomes. We performed a genome-wide comparative analysis of the promoters of human lncRNA and protein-coding genes, finding global differences in specific genetic and epigenetic features relevant to transcriptional regulation. These two groups of genes are hence subject to separate transcriptional regulatory programs, including distinct transcription factor (TF) proteins that significantly favor lncRNA, rather than coding-gene, promoters. We report a specific signature of promoter-proximal transcriptional regulation of lncRNA genes, including several distinct transcription factor binding sites (TFBS). Experimental DNase I hypersensitive site profiles are consistent with active configurations of these lncRNA TFBS sets in diverse human cell types. TFBS ChIP-seq datasets confirm the binding events that we predicted using computational approaches for a subset of factors. For several TFs known to be directly regulated by lncRNAs, we find that their putative TFBSs are enriched at lncRNA promoters, suggesting that the TFs and the lncRNAs may participate in a bidirectional feedback loop regulatory network. Accordingly, cells may be able to modulate lncRNA expression levels independently of mRNA levels via distinct regulatory pathways. Our results also raise the possibility that, given the historical reliance on protein-coding gene catalogs to define the chromatin states of active promoters, a revision of these chromatin signature profiles to incorporate expressed lncRNA genes is warranted in the future.

  14. PIRACY REGULATION AND THE FILIPINO’S HISTORICAL RESPONSE TO GLOBALIZATION

    Directory of Open Access Journals (Sweden)

    Rolando B. Tolentino

    2009-12-01

    Full Text Available The essay examines the racial discourse of Moros and Moro-profiling by the state in piracy—sea piracy in olden times and media piracy in contemporary times. Moro piracy becomes a local cosmopolitanism in the Philippines’ attempt to integrate in various eras of global capitalism. From the analysis of media piracy, the Moro “dibidi” (pirated DVD seller becomes the body that mediates between the Filipinos’ middle-class fantasy of a branded lifestyle and the reality that most Filipinos do not have full access to global consumerism. Using a cultural studies framework, the essay draws a connection between seemingly unlinked events and sources, allowing for a historical and social dialog, past and present, to mix, creating junctures for sites of dialog and critique.

  15. Strategies for restoration of deep-water coral ecosystems based on a global survey of oil and gas regulations

    Science.gov (United States)

    Cordes, E. E.; Jones, D.; Levin, L. A.

    2016-02-01

    The oil and gas industry is one of the most active agents of the global industrialization of the deep sea. The wide array of impacts following the Deepwater Horizon oil spill highlighted the need for a systematic review of existing regulations both in US waters and internationally. Within different exclusive economic zones, there are a wide variety of regulations regarding the survey of deep-water areas prior to leasing and the acceptable set-back distances from vulnerable marine ecosystems once they are discovered. There are also varying mitigation strategies for accidental release of oil and gas, including active monitoring systems, temporary closings of oil and gas production, and marine protected areas. The majority of these regulations are based on previous studies of typical impacts from oil and gas drilling, rather than accidental releases. However, the probability of an accident from standard operations increases significantly with depth. The Oil & Gas working group of the Deep Ocean Stewardship Initiative is an international partnership of scientists, managers, non-governmental organizations, and industry professionals whose goal is to review existing regulations for the oil & gas industry and produce a best practices document to advise both developed and developing nations on their regulatory structure as energy development moves into deeper waters.

  16. DNA Repair and Global Sumoylation Are Regulated by Distinct Ubc9 Noncovalent Complexes ▿

    OpenAIRE

    Prudden, John; Perry, J. Jefferson P.; Nie, Minghua; Ajay A Vashisht; Arvai, Andrew S.; Hitomi, Chiharu; Guenther, Grant; Wohlschlegel, James A; Tainer, John A.; Boddy, Michael N

    2011-01-01

    Global sumoylation, SUMO chain formation, and genome stabilization are all outputs generated by a limited repertoire of enzymes. Mechanisms driving selectivity for each of these processes are largely uncharacterized. Here, through crystallographic analyses we show that the SUMO E2 Ubc9 forms a noncovalent complex with a SUMO-like domain of Rad60 (SLD2). Ubc9:SLD2 and Ubc9:SUMO noncovalent complexes are structurally analogous, suggesting that differential recruitment of Ubc9 by SUMO or Rad60 p...

  17. Soxhlet-assisted matrix solid phase dispersion to extract flavonoids from rape (Brassica campestris) bee pollen.

    Science.gov (United States)

    Ma, Shuangqin; Tu, Xijuan; Dong, Jiangtao; Long, Peng; Yang, Wenchao; Miao, Xiaoqing; Chen, Wenbin; Wu, Zhenhong

    2015-11-15

    Soxhlet-assisted matrix solid phase dispersion (SA-MSPD) method was developed to extract flavonoids from rape (Brassica campestris) bee pollen. Extraction parameters including the extraction solvent, the extraction time, and the solid support conditions were investigated and optimized. The best extraction yields were obtained using ethanol as the extraction solvent, silica gel as the solid support with 1:2 samples to solid support ratio, and the extraction time of one hour. Comparing with the conventional solvent extraction and Soxhlet method, our results show that SA-MSPD method is a more effective technique with clean-up ability. In the test of six different samples of rape bee pollen, the extracted content of flavonoids was close to 10mg/g. The present work provided a simple and effective method for extracting flavonoids from rape bee pollen, and it could be applied in the studies of other kinds of bee pollen. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Bioconversion from crude glycerin by Xanthomonas campestris 2103: xanthan production and characterization

    Directory of Open Access Journals (Sweden)

    L. V. Brandão

    2013-12-01

    Full Text Available The production and rheological properties of xanthan gum from crude glycerin fermentation, a primary by-product of the biodiesel industry with environmental and health risks, were evaluated. Batch fermentations (28 °C/250 rpm /120 h were carried out using crude glycerin, 0.01% urea and 0.1% KH2PO4, (% w/v, and compared to a sucrose control under the same operational conditions, using Xanthomonas campestris strain 2103 isolate from Brazil. Its maximal production by crude glycerin fermentation was 7.23±0.1 g·L-1 at 120 h, with an apparent viscosity of 642.57 mPa·s, (2 % w/v, 25 °C, 25 s-1, 70% and 30% higher than from sucrose fermentation, respectively. Its molecular weight varied from 28.2 to 36.2×10(6 Da. The Ostwald-de-Waele model parameters (K and n indicated a pseudoplastic behavior at all concentrations (0.5 to 2.0 %, w/v and temperatures (25-85 °C, while its consistency index indicated promising rheological properties for drilling fluid applications. Therefore, crude glycerin has potential as a cost-effective and alternative substrate for non-food grade xanthan production.

  19. Limpeza clonal de mudas de videira infectadas por Xanthomonas campestris pv. viticola

    Directory of Open Access Journals (Sweden)

    Adriano Márcio Freire Silva

    2013-03-01

    Full Text Available O cancro bacteriano da videira é causado por Xanthomonas campestris pv. viticola (Xcv. Visando à limpeza clonal de mudas de 'Red Globe', foram estudados: tamanho ideal de ápices e gemas axilares para cultivo em meio de Galzy modificado (MGM; efeito da termoterapia (38ºC/30 dias; e ação de antibióticos na eliminação de Xcv em videiras infectadas. Os percentuais de contaminação por Xcv e de regeneração foram analisados, e as plantas obtidas foram indexadas em meio ágar nutritivo-dextrose-extrato de levedura-ampicilina (NYDAM, seguindo-se teste de patogenicidade. O cultivo de explantes com 3 mm possibilitou a obtenção de plantas livres da bactéria, com regeneração 14,3 vezes maior que explantes com 1 mm. A termoterapia de mudas infectadas, associada ao cultivo in vitro, não eliminou o patógeno. O cultivo de explantes com 10 mm, durante 40 dias em MGM + cefotaxima (300 mg L-1, proporcionou limpeza clonal das mudas. A indexação de plantas de videira regeneradas in vitro, quanto à infecção por Xcv utilizando NYDAM, seguida de teste de patogenicidade, é uma alternativa econômica e eficiente para produção de mudas de alta qualidade fitossanitária.

  20. Kinetic models for xanthan gum production using Xanthomonas campestris from molasses

    Directory of Open Access Journals (Sweden)

    S.L. GILANI

    2011-06-01

    Full Text Available The effects of media temperature, agitation rate and molasses concentration on the yield of fermentation in xanthan gum production process were investigated. Xanthan gum was produced in batch fermentation by Xanthomonas campestris PTCC 1473 from molasses. At 32 C, 500 rpm and media with 30 g/l of total sugar, maximum production of xanthan gum (17.1 g/l was achieved. For the purity of the xanthan FTIR spectrum was obtained. The identified spectrum was compared with the commercial product. In batch culture, several kinetic models for the biochemical reactions were extensively studied. The growth kinetic parameters were evaluated by unstructured model and derived from the related equations. Based on Malthus and Logistic rate equations, the maximum specific growth rate, max, and initial cell dry weight, X0, were defined. Luedeking-Piret and Modified Luedeking-Piret models were applied for the product formation and substrate consumption rates. In batch experiments, the kinetic parameters for the growth associated (m, a and non-growth associated (n, b parameters were determined.

  1. Effect of alcoholic extract of guaco (Mikania glomerata on the control of dark rot (Xanthomonas campestris pv. campestris in cauliflower/ Avaliação da eficácia da tintura etanólica de guaco (Mikania glomerata no controle da podridão negra (Xanthomonas campestris pv. campestris em couve-flor

    Directory of Open Access Journals (Sweden)

    Kátia Regina Freitas Schwan-Estrada

    2006-06-01

    Full Text Available With the use of irrigation and new hybrids of cauliflower, it is possible to get production during all the year with hight yield. However, the crop has been affected by diseases, as the dark rot caused by X. campestris pv. campestris. The objective of this research work was to study the potential of Mikania glomerata for the control of this disease. Alcoholic extract 50 ºGL of M. glomerata was evaluated regarding to: in vitro antimicrobial activity through bacterial growth in 100, 250, 500 and 1000 mg L-1 of the alcoholic extract; induction of local or systemic resistance in 25 days old cauliflower, with spray of alcoholic extract concomitantly and three days before the inoculation with the pathogen (water and bordeau mixture were used as control; peroxidases activity in leaves of cauliflower treated and not treated, and harvested concomitantly, 24, 48 and 72 hours after spraying the alcoholic extract and also after inoculation. The alcoholic extract of M. glomerata showed inhibition of the bacterial growth in vitro at the concentrations of 250, 500 and 1000 mg L-1. The concentrations of 500 mg L-1 and 1000 mg L-1 inhibited 24% and 38% of the bacterial growth. This inhibition could be due to antibacterial compounds in the alcoholic extract. An inhibition of the disease in vivo occurred only in the leaves treated with 100 and 500 mg L-1 of alcoholic extract when applied concomitantly with the bacteria. This result was similar to bordeau mixture, indicating a control by direct antimicrobial activity. There was no systemic resistence induction for all treatments. The peroxidases induction was due to infectious pathogen process and not to the treatments with alcoholic extract. The results indicate the potential of M. glomerata alcoholic extract for the preventive control of cauliflower dark rot disease.Com a prática da irrigação e novos híbridos de couve-flor, é possível produzir durante todo o ano e com alta produtividade. Mas, a cultura tem

  2. Selenium alleviates chromium toxicity by preventing oxidative stress in cabbage (Brassica campestris L. ssp. Pekinensis) leaves.

    Science.gov (United States)

    Qing, Xuejiao; Zhao, Xiaohu; Hu, Chengxiao; Wang, Peng; Zhang, Ying; Zhang, Xuan; Wang, Pengcheng; Shi, Hanzhi; Jia, Fen; Qu, Chanjuan

    2015-04-01

    The beneficial role of selenium (Se) in alleviation of chromium (Cr)-induced oxidative stress is well established. However, little is known about the underlying mechanism. The impacts of exogenous Se (0.1mg/L) on Cr(1mg/L)-induced oxidative stress and antioxidant systems in leaves of cabbage (Brassica campestris L. ssp. Pekinensis) were investigated by using cellular and biochemical approaches. The results showed that supplementation of the medium with Se was effective in reducing Cr-induced increased levels of lipid peroxides and superoxide free radicals (O(-)2(·)), as well as increasing activities of superoxide dismutase (SOD) and peroxidase (POD). Meanwhile, 1mg/L Cr induced loss of plasma membrane integrity, growth inhibition, as well as ultrastructural changes of leaves were significantly reversed due to Se supplementation in the medium. In addition, Se application significantly altered the subcellular distribution of Cr which transported from mitochondria, nucleus and the cell-wall material to the soluble fraction and chloroplasts. However, Se application did no significant alteration of Cr effects on osmotic adjustment accumulating products. The study suggested that Se is able to protect leaves of cabbage against Cr toxicity by alleviation of Cr induced oxidative stress, and re-distribution of Cr in the subcellular of the leaf. Furthermore, free radicals, lipid peroxides, activity of SOD and POD, and subcellular distribution of Cr can be considered the efficient biomarkers to indicate the efficiency of Se to detoxification Cr. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Antimicrobial and Antioxidant Activities of Coumarins from the Roots of Ferulago campestris (Apiaceae

    Directory of Open Access Journals (Sweden)

    2009-02-01

    Full Text Available We report the isolation of several coumarins and the stereochemical assessment of some pyranocoumarins, as well as the antibacterial and antioxidant activities of the three most abundant ones (grandivittin, agasyllin and aegelinol benzoate isolated from the roots of Ferulago campestris collected in Sicily and of the hydrolysis product (aegelinol. Aegelinol and agasyllin showed antibacterial activity against nine ATCC and the same clinically isolated Gram-positive and Gram-negative bacterial strains. At a concentration between 16 and 125 mg/mL both coumarins showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In particular the ATCC strains Staphylococcus aureus, Salmonella thypii, Enterobacter cloacae and Enterobacter earogenes (MIC = 16 and 32 mg/mL for aegelinol and agasyllin, respectively were the most inhibited. Antibacterial activity was also found against Helicobacter pylori: a dose-dependent inhibition was shown between 5 and 25 mg/mL. The antioxidant activity of the coumarins was evaluated by their effects on human whole blood leukocytes (WB and on isolated polymorphonucleate (PMN chemiluminescence (CL, PMA-stimulated and resting.

  4. Xanthan biosynthesis by Xanthomonas campestris ATCC 13951 on wastewaters from white grape processing

    Directory of Open Access Journals (Sweden)

    Rončević Zorana

    2017-01-01

    Full Text Available Wastewaters from grape processing in wineries are characterized by large seasonal fluctuations in volume and composition, and are often discarded into environment with little or no treatment. The biotechnological production of valuable products is the most promising alternative for reducing the negative environmental impact and recycling these effluents. Results from previous study show that mixed winery wastewaters, after additional optimization of the medium preparation, may be a suitable raw material for industrial xanthan production. Therefore, the aim of this work was to examine the possibility of xanthan production by Xanthomonas campestris ATCC 13951 on mixed wastewaters from different stages of white grape processing in winery with initial sugars content of 20 g/L. In addition to the media characteristics and indicators of biopolymer quality, raw xanthan yield and degree of sugars conversion into product were determined in order to examine the success of performed bioprocess. The results for biopolymer yield (14.66 g/L and sugars conversion into desired product (70.21% obtained in applied experimental conditions confirm that wastewaters from white grape processing have a great potential to be used as a substrate for xanthan biosynthesis.

  5. Structure of global buyer-supplier networks and its implications for conflict minerals regulations

    CERN Document Server

    Mizuno, Takayuki; Watanabe, Tsutomu

    2015-01-01

    We investigate the structure of global inter-firm linkages using a dataset that contains information on business partners for about 400,000 firms worldwide, including all the firms listed on the major stock exchanges. Among the firms, we examine three networks, which are based on customer-supplier, licensee-licensor, and strategic alliance relationships. First, we show that these networks all have scale-free topology and that the degree distribution for each follows a power law with an exponent of 1.5. The shortest path length is around six for all three networks. Second, we show through community structure analysis that the firms comprise a community with those firms that belong to the same industry but different home countries, indicating the globalization of firms' production activities. Finally, we discuss what such production globalization implies for the proliferation of conflict minerals (i.e., minerals extracted from conflict zones and sold to firms in other countries to perpetuate fighting) through g...

  6. LeuO is a global regulator of gene expression in Salmonella enterica serovar Typhimurium

    DEFF Research Database (Denmark)

    Dillon, Shane C.; Espinosa, Elena; Hokamp, Karsten

    2012-01-01

    We report the first investigation of the binding of the Salmonella enterica LeuO LysR‐type transcription regulator to its genomic targets in vivo. Chromatin‐immunoprecipitation‐on‐chip identified 178 LeuO binding sites on the chromosome of S. enterica serovar Typhimurium strain SL1344. These site...

  7. Global discovery of erythroid long noncoding RNAs reveals novel regulators of red cell maturation

    NARCIS (Netherlands)

    Alvarez-Dominguez, Juan R; Hu, Wenqian; Yuan, Bingbing; Shi, Jiahai; Park, Staphany S; Gromatzky, Austin A; van Oudenaarden, Alexander; Lodish, Harvey F

    2014-01-01

    Erythropoiesis is regulated at multiple levels to ensure the proper generation of mature red cells under multiple physiological conditions. To probe the contribution of long noncoding RNAs (lncRNAs) to this process, we examined >1 billion RNA-seq reads of polyadenylated and nonpolyadenylated RNA

  8. Modulation of the norfloxacin resistance in Staphylococcus aureus by Croton campestris A. and Ocimum gratissimum L. Modulación de la resistencia a norfloxacina de Staphylococcus aureus por Croton A. campestris y Ocimum gratissimum L.

    Directory of Open Access Journals (Sweden)

    José P. Siqueira-Júnior

    2011-06-01

    Full Text Available

    Introduction: Some species of Staphylococcus are often recognized as etiological agents of many animal and human opportunistic infections. This study is the first test of change in resistance of
    antibiotic activity by Croton campestris A. and Ocimum gratissimum L. against multiresistant strains of Staphylococcus aureus.
    Objective: In this study, the hexane and methanol extract of Croton campestris A. and Ocimum gratissimum L. was tested for antibacterial activity alone and in combination with norfloxacin against the strain SA1199B.
    Materials and methods: The minimum inhibitory concentration (MIC and the modulatory effect of extracts was assayed using microtitre assay.
    Results: By the fact of the MIC observed was not clinically relevant (MIC= 512 to ≥1.024 μg/ml, the antibiotic activity of norfloxacin was enhanced when this antibiotic was combined with sub-inhibitory concentrations of extracts, mainly the hexane extracts.
    Conclusions: These results indicate that the assayed extracts present compounds that can be used as a putative efflux pump inhibitor, indicating that Croton campestris A. and Ocimum gratissimum L. can be a source of plant derived products with antibiotic modifier activity.

    Introducción. Algunas especies de Staphylococcus suelen ser reconocidas como agentes etiológicos de muchas infecciones oportunistas en animales y em humanos. Este estudio es la primera prueba del
    cambio en la resistencia de la actividad antibiótica por Croton campestris A. y Ocimum gratissimum L. contra cepas multirresistentes de Staphylococcus aureus.
    Objetivo. Ensayar la actividad antibacteriana de los extractos hexánicos y metanólicos de Croton campestris A. y Ocimum gratissimum L. sola y en combinación con norfloxacina sobre la cepa SA1199B.
    Materiales y métodos. Se analizó la concentración inhibitoria mínima (CIM y el efecto modulador de los extractos usando el ensayo de microtitulaci

  9. Global Health Security Demands a Strong International Health Regulations Treaty and Leadership From a Highly Resourced World Health Organization.

    Science.gov (United States)

    Burkle, Frederick M

    2015-10-01

    If the Ebola tragedy of West Africa has taught us anything, it should be that the 2005 International Health Regulations (IHR) Treaty, which gave unprecedented authority to the World Health Organization (WHO) to provide global public health security during public health emergencies of international concern, has fallen severely short of its original goal. After encouraging successes with the 2003 severe acute respiratory syndrome (SARS) pandemic, the intent of the legally binding Treaty to improve the capacity of all countries to detect, assess, notify, and respond to public health threats has shamefully lapsed. Despite the granting of 2-year extensions in 2012 to countries to meet core surveillance and response requirements, less than 20% of countries have complied. Today it is not realistic to expect that these gaps will be solved or narrowed in the foreseeable future by the IHR or the WHO alone under current provisions. The unfortunate failures that culminated in an inadequate response to the Ebola epidemic in West Africa are multifactorial, including funding, staffing, and poor leadership decisions, but all are reversible. A rush by the Global Health Security Agenda partners to fill critical gaps in administrative and operational areas has been crucial in the short term, but questions remain as to the real priorities of the G20 as time elapses and critical gaps in public health protections and infrastructure take precedence over the economic and security needs of the developed world. The response from the Global Outbreak Alert and Response Network and foreign medical teams to Ebola proved indispensable to global health security, but both deserve stronger strategic capacity support and institutional status under the WHO leadership granted by the IHR Treaty. Treaties are the most successful means the world has in preventing, preparing for, and controlling epidemics in an increasingly globalized world. Other options are not sustainable. Given the gravity of ongoing

  10. Sapfluxnet: a global database of sap flow measurements to unravel the ecological factors of transpiration regulation in woody plants

    Science.gov (United States)

    Poyatos, Rafael; Martínez-Vilalta, Jordi; Molowny-Horas, Roberto; Steppe, Kathy; Oren, Ram; Katul, Gabriel; Mahecha, Miguel

    2016-04-01

    Plant transpiration is one of the main components of the global water cycle, it controls land energy balance, determines catchment hydrological responses and exerts strong feedbacks on regional and global climate. At the same time, plant productivity, growth and survival are severely constrained by water availability, which is expected to decline in many areas of the world because of global-change driven increases in drought conditions. While global surveys of drought tolerance traits at the organ level are rapidly increasing our knowledge of the diversity in plant functional strategies to cope with drought stress, a whole-plant perspective of drought vulnerability is still lacking. Sap flow measurements using thermal methods have now been applied to measure seasonal patterns in water use and the response of transpiration to environmental drivers across hundreds of species of woody plants worldwide, covering a wide range of climates, soils and stand structural characteristics. Here, we present the first effort to build a global database of sub-daily, tree-level sap flow (SAPFLUXNET) that will be used to improve our understanding of physiological and structural determinants of plant transpiration and to further investigate the role of vegetation in controlling global water balance. We already have the expression of interest of data contributors representing >115 globally distributed sites, > 185 species and > 700 trees, measured over at least one growing season. However, the potential number of available sites and species is probably much higher given that > 2500 sap flow-related papers have been identified in a Scopus literature search conducted in November 2015. We will give an overview of how data collection, harmonisation and quality control procedures are implemented within the project. We will also discuss potential analytical strategies to synthesize hydroclimatic controls on sap flow into biologically meaningful traits related to whole-plant transpiration

  11. Global harmonization of food safety regulation from the perspective of Korea and a novel fast automatic product recall system.

    Science.gov (United States)

    Sohn, Mun-Gi; Oh, Sangsuk

    2014-08-01

    Efforts have been made for global harmonization of food safety regulations among countries through international organizations such as WTO and WHO/FAO. Global harmonization of food safety regulations is becoming increasingly important for Korean consumers because more than half of food and agricultural products are imported and consumed. Through recent reorganization of the Korean government, a consolidated national food safety authority-the Ministry of Food and Drug Safety (MFDS)-has been established for more efficient food safety control and better communication with consumers. The Automatic Sales Blocking System (ASBS), which blocks the sales of the recalled food products at the point of sale, has been implemented at over 40,000 retail food stores around the nation using state-of-the art information and communication technology (ICT) for faster recall of adulterated food products, and the e-Food Safety Control System has been developed for more efficient monitoring of national food safety surveillance situations. The National Food Safety Information Service was also established for monitoring and collecting food safety information and incidents worldwide, and shares relevant information with all stakeholders. The new approaches adopted by the Korean Food Safety Authority are expected to enhance public trust with regard to food safety issues and expedite the recall process of adulterated products from the market. © 2013 Society of Chemical Industry.

  12. The Xanthomonas campestris gumD gene required for synthesis of xanthan gum is involved in normal pigmentation and virulence in causing black rot.

    Science.gov (United States)

    Chou, F L; Chou, H C; Lin, Y S; Yang, B Y; Lin, N T; Weng, S F; Tseng, Y H

    1997-04-07

    A cloned 4.1-kb EcoRI fragment from Xanthomonas campestris pv. campestris was previously shown to complement the non-mucoid mutant P22 and increase xanthan gum production after being transformed into the wild-type strain Xc17. The gene responsible for these effects was identified, sequenced, and shown to be the gumD gene which has previously been proposed to encode glucose transferase activity, an enzyme required for adding the first glucose residue to the isoprenoid glycosyl carrier lipid during xanthan synthesis. A gumD mutant, isolated from Xc17 by gene replacement, was shown to possess altered pigment xanthomonadin profiles and exhibit reduced virulence in causing black rot in broccoli. This study appears to be the first to demonstrate that interruption of a gene required for xanthan synthesis can lead to reduced virulence of X. campestris.

  13. Systems Chronobiology: Global Analysis of Gene Regulation in a 24-Hour Periodic World.

    Science.gov (United States)

    Mermet, Jérôme; Yeung, Jake; Naef, Felix

    2017-03-01

    Mammals have evolved an internal timing system, the circadian clock, which synchronizes physiology and behavior to the daily light and dark cycles of the Earth. The master clock, located in the suprachiasmatic nucleus (SCN) of the brain, takes fluctuating light input from the retina and synchronizes other tissues to the same internal rhythm. The molecular clocks that drive these circadian rhythms are ticking in nearly all cells in the body. Efforts in systems chronobiology are now being directed at understanding, on a comprehensive scale, how the circadian clock controls different layers of gene regulation to provide robust timing cues at the cellular and tissue level. In this review, we introduce some basic concepts underlying periodicity of gene regulation, and then highlight recent genome-wide investigations on the propagation of rhythms across multiple regulatory layers in mammals, all the way from chromatin conformation to protein accumulation. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

  14. Enhancing Social Responsibility within Global Supply Chains: Is Legal Regulation the Optimal Solution?

    Directory of Open Access Journals (Sweden)

    Katerina Peterková

    2011-03-01

    Full Text Available This paper was presented at the first meeting of the NSU study group “Conceptions of ethical and social values in post-secular society: Towards a new ethical imagination in a cosmopolitan world society”, held on January 28-30, 2011 at Copenhagen Business School. First, this paper examines the voluntary (ethical v. mandatory (legal basis of corporate social responsibility (CSR. Second, it examines the relationship between CSR, law and business ethics. Third, it tries to answer the question if there is a need for a hard[2] legal regulation of CSR within international supply relationships or if ethical norms, e.g. expressed in the form of self-regulation, may better serve the purpose. And finally, it suggests possible ways for the future development of suitable regulatory methods for enhancing social standards within international supply chains. The questions are approached solely from the perspectives of legal theory and socio-legal analysis.

  15. Genome architecture and global gene regulation in bacteria: making progress towards a unified model?

    Science.gov (United States)

    Dorman, Charles J

    2013-05-01

    Data obtained with advanced imaging techniques, chromosome conformation capture methods, bioinformatics and molecular genetics, together with insights from polymer physics and mechanobiology, are helping to refine our understanding of the spatiotemporal organization of the bacterial nucleoid and its gene expression programmes. Here, I discuss the proposal that, in addition to DNA topology and nucleoid-associated proteins, gene regulation is an important organizing principle of nucleoid architecture.

  16. Function of global regulator CodY in Bacillus thuringiensis BMB171 by comparative proteomic analysis.

    Science.gov (United States)

    Qi, Mingxia; Mei, Fei; Wang, Hui; Sun, Ming; Wang, Gejiao; Yu, Ziniu; Je, Yeonho; Li, Mingshun

    2015-02-01

    CodY is a highly conserved protein in low G+C gram-positive bacteria that regulates genes involved in sporulation and stationary-phase adaptation. Bacillus thuringiensis is a grampositive bacterium that forms spores and parasporal crystals during the stationary phase. To our knowledge, the regulatory mechanism of CodY in B. thuringiensis is unknown. To study the function of CodY protein in B. thuringiensis, BMB171codY(-) was constructed in a BMB171 strain. A shuttle vector containing the ORF of cry1Ac10 was transformed into BMB171 and BMB171codY(-), named BMB171cry1Ac and BMB171codY(-)cry1Ac, respectively. Some morphological and physiological changes of codY mutant BMB171codY(-)cry1Ac were observed. A comparative proteomic analysis was conducted for both BMB171codY(-)cry1Ac and BMB171cry1Ac through two-dimensional gel electrophoresis and MALDI-TOF-MS/MS analysis. The results showed that the proteins regulated by CodY are involved in microbial metabolism, including branched-chain amino acid metabolism, carbohydrate metabolism, fatty acid metabolism, and energy metabolism. Furthermore, we found CodY to be involved in sporulation, biosynthesis of poly-β-hydroxybutyrate, growth, genetic competence, and translation. According to the analysis of differentially expressed proteins, and physiological characterization of the codY mutant, we performed bacterial one-hybrid and electrophoretic mobility shift assay experiments and confirmed the direct regulation of genes by CodY, specifically those involved in metabolism of branched-chain amino acids, ribosomal recycling factor FRR, and the late competence protein ComER. Our data establish the foundation for in-depth study of the regulation of CodY in B. thuringiensis, and also offer a potential biocatalyst for functions of CodY in other bacteria.

  17. Global expression profiling of theophylline response genes in macrophages: evidence of airway anti-inflammatory regulation

    Science.gov (United States)

    Yao, Pei-Li; Tsai, Meng-Feng; Lin, Yi-Chen; Wang, Chien-Hsun; Liao, Wei-Yu; Chen, Jeremy JW; Yang, Pan-Chyr

    2005-01-01

    Background Theophylline has been used widely as a bronchodilator for the treatment of bronchial asthma and has been suggested to modulate immune response. While the importance of macrophages in asthma has been reappraised and emphasized, their significance has not been well investigated. We conducted a genome-wide profiling of the gene expressions of macrophages in response to theophylline. Methods Microarray technology was used to profile the gene expression patterns of macrophages modulated by theophylline. Northern blot and real-time quantitative RT-PCR were also used to validate the microarray data, while Western blot and ELISA were used to measure the levels of IL-13 and LTC4. Results We identified dozens of genes in macrophages that were dose-dependently down- or up-regulated by theophylline. These included genes related to inflammation, cytokines, signaling transduction, cell adhesion and motility, cell cycle regulators, and metabolism. We observed that IL-13, a central mediator of airway inflammation, was dramatically suppressed by theophylline. Real-time quantitative RT-PCR and ELISA analyses also confirmed these results, without respect to PMA-treated THP-1 cells or isolated human alveolar macrophages. Theophylline, rolipram, etazolate, db-cAMP and forskolin suppressed both IL-13 mRNA expression (~25%, 2.73%, 8.12%, 5.28%, and 18.41%, respectively) and protein secretion (theophylline may be through cAMP mediation and may decrease LTC4 production. This study supports the role of theophylline as a signal regulator of inflammation, and that down regulation of IL-13 by theophylline may have beneficial effects in inflammatory airway diseases. PMID:16083514

  18. Essential Oil Variability in Natural Populations of Artemisia campestris (L.) and Artemisia herba-alba (Asso) and Incidence on Antiacetylcholinesterase and Antioxidant Activities.

    Science.gov (United States)

    Younsi, Faten; Mehdi, Sameh; Aissi, Oumayma; Rahali, Najoua; Jaouadi, Rym; Boussaid, Mohamed; Messaoud, Chokri

    2017-07-01

    The intraspecific variability of Artemisia herba-alba and A. campestris essential oils and the evaluation of their antioxidant and antiacetylcholinesterase activities were determined. Artemisia herba-alba essential oil was found rich in camphor (19.61%), α-thujone (19.40%), β-thujone (9.44%), chrysanthenone (9.26%), and trans-sabinyl acetate (8.43%). The major compounds of A. campestris essential oil were germacrene D (16.38%), β-pinene (16.33%), and limonene (9.17%). Significant variation in the essential oil composition was observed among populations of each species. The divergence between populations was attributed to the variation of some climatic factors such as altitude, annual rainfall, winter cold stress, summer precipitation, summer drought stress, evapotranspiration, and humidity. Artemisia herba-alba and A. campestris essential oils exhibited promising antioxidant and antiacetylcholinesterase activities. The level of activity varied significantly according to the species and the essential oil. The highest scavenging activity (IC 50 = 0.14 mg/ml) and the uppermost capacity to prevent β-carotene bleaching (IC 50 = 0.10 mg/ml) characterized A. campestris from population 6. A. campestris population 3 possessed the uppermost ability to reduce ferric ions (450.7 μmol Fe 2+ /g EO). The population 2 of A. campestris showed the strongest antiacetylcholinesterase activity (IC 50 = 0.02 mg/ml). The variation of these activities between the essential oils was explained by their composition differences. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  19. Sensitive and specific detection of Xanthomonas campestris pv. pelargonii with DNA primers and probes identified by random amplified polymorphic DNA analysis.

    Science.gov (United States)

    Manulis, S; Valinsky, L; Lichter, A; Gabriel, D W

    1994-11-01

    The random amplified polymorphic DNA method was used to distinguish strains of Xanthomonas campestris pv. pelargonii from 21 other Xanthomonas species and/or pathovars. Among the 42 arbitrarily chosen primers evaluated, 3 were found to reveal diagnostic polymorphisms when purified DNAs from compared strains were amplified by the PCR. The three primers revealed DNA amplification patterns which were conserved among all 53 strains tested of X. campestris pv. pelargonii isolated from various locations worldwide. The distinctive X. compestris pv. pelargonii patterns were clearly different from those obtained with any of 46 other Xanthomonas strains tested. An amplified 1.2-kb DNA fragment, apparently unique to X. campestris pv. pelargonii by these random amplified polymorphic DNA tests, was cloned and evaluated as a diagnostic DNA probe. It hybridized with total DNA from all 53 X. campestris pv. pelargonii strains tested and not with any of the 46 other Xanthomonas strains tested. The DNA sequence of the terminal ends of this 1.2-kb fragment was obtained and used to design a pair of 18-mer oligonucleotide primers specific for X. campestris pv. pelargonii. The custom-synthesized primers amplified the same 1.2-kb DNA fragment from all 53 X. campestris pv. pelargonii strains tested and failed to amplify DNA from any of the 46 other Xanthomonas strains tested. DNA isolated from saprophytes associated with the geranium plant also did not produce amplified DNA with these primers. The sensitivity of the PCR assay using the custom-synthesized primers was between 10 and 50 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Establishment of an in vitro system for studies on the induced resistance of cotton to Xanthomonas campestris pv. malvacearum Estabelecimento de sistema in vitro para estudos da resistência induzida à Xanthomonas campestris pv. malvacearum em algodoeiro

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    ADILSON KENJI KOBAYASHI

    2000-04-01

    Full Text Available An in vitro system for studying the resistance response of cotton (Gossypium hirsutum L. to Xanthomonas campestris pv. malvacearum was investigated. Cell suspension cultures, established from hypocotyl-derived callus of cotton cultivar 101-102B, were treated with bacterial extracellular polysaccharides (EPS extracted from the incompatible race 18 of X. campestris pv. malvacearum. EPS at 600 mug/mL caused pronounced darkening of the suspension cultures, as indicative of cell death, 48 hours after incubation. Protein electrophoresis analysis of the time course of EPS-treated cells showed differential accumulation of several protein bands after 12-24 hours. The time course of protein accumulation and cell death was consistent with an elicitor-mediated hypersensitive response.Desenvolveu-se um sistema in vitro para estudar a resistência do algodoeiro (Gossypium hirsutum L. à Xanthomonas campestris pv. malvacearum. Foram utilizados calos originados a partir de hipocótilos da cultivar de algodoeiro 101-102B para estabelecer culturas de células em suspensão, as quais foram tratadas com polissacarídeos extracelulares bacterianos (EPS extraídos da raça incompatível 18 de X. campestris pv. malvacearum. O tratamento com EPS, na concentração de 600 mig/mL, causou acentuado escurecimento das culturas em suspensão, indicativo de morte celular, 48 horas após a incubação. A análise temporal do perfil eletroforético de proteínas extraídas das células tratadas com EPS mostrou um acúmulo diferencial de diversas proteínas após 12-24 horas. O acúmulo de proteínas e a morte celular ao longo do período estudado foram consistentes com um padrão de resposta de hipersensibilidade causada por elicitores.

  1. DNA repair and global sumoylation are regulated by distinct Ubc9 noncovalent complexes.

    Science.gov (United States)

    Prudden, John; Perry, J Jefferson P; Nie, Minghua; Vashisht, Ajay A; Arvai, Andrew S; Hitomi, Chiharu; Guenther, Grant; Wohlschlegel, James A; Tainer, John A; Boddy, Michael N

    2011-06-01

    Global sumoylation, SUMO chain formation, and genome stabilization are all outputs generated by a limited repertoire of enzymes. Mechanisms driving selectivity for each of these processes are largely uncharacterized. Here, through crystallographic analyses we show that the SUMO E2 Ubc9 forms a noncovalent complex with a SUMO-like domain of Rad60 (SLD2). Ubc9:SLD2 and Ubc9:SUMO noncovalent complexes are structurally analogous, suggesting that differential recruitment of Ubc9 by SUMO or Rad60 provides a novel means for such selectivity. Indeed, deconvoluting Ubc9 function by disrupting either the Ubc9:SLD2 or Ubc9:SUMO noncovalent complex reveals distinct roles in facilitating sumoylation. Ubc9:SLD2 acts in the Nse2 SUMO E3 ligase-dependent pathway for DNA repair, whereas Ubc9:SUMO instead promotes global sumoylation and chain formation, via the Pli1 E3 SUMO ligase. Moreover, this Pli1-dependent SUMO chain formation causes the genome instability phenotypes of SUMO-targeted ubiquitin ligase (STUbL) mutants. Overall, we determine that, unexpectedly, Ubc9 noncovalent partner choice dictates the role of sumoylation in distinct cellular pathways.

  2. DNA Repair and Global Sumoylation Are Regulated by Distinct Ubc9 Noncovalent Complexes ▿

    Science.gov (United States)

    Prudden, John; Perry, J. Jefferson P.; Nie, Minghua; Vashisht, Ajay A.; Arvai, Andrew S.; Hitomi, Chiharu; Guenther, Grant; Wohlschlegel, James A.; Tainer, John A.; Boddy, Michael N.

    2011-01-01

    Global sumoylation, SUMO chain formation, and genome stabilization are all outputs generated by a limited repertoire of enzymes. Mechanisms driving selectivity for each of these processes are largely uncharacterized. Here, through crystallographic analyses we show that the SUMO E2 Ubc9 forms a noncovalent complex with a SUMO-like domain of Rad60 (SLD2). Ubc9:SLD2 and Ubc9:SUMO noncovalent complexes are structurally analogous, suggesting that differential recruitment of Ubc9 by SUMO or Rad60 provides a novel means for such selectivity. Indeed, deconvoluting Ubc9 function by disrupting either the Ubc9:SLD2 or Ubc9:SUMO noncovalent complex reveals distinct roles in facilitating sumoylation. Ubc9:SLD2 acts in the Nse2 SUMO E3 ligase-dependent pathway for DNA repair, whereas Ubc9:SUMO instead promotes global sumoylation and chain formation, via the Pli1 E3 SUMO ligase. Moreover, this Pli1-dependent SUMO chain formation causes the genome instability phenotypes of SUMO-targeted ubiquitin ligase (STUbL) mutants. Overall, we determine that, unexpectedly, Ubc9 noncovalent partner choice dictates the role of sumoylation in distinct cellular pathways. PMID:21444718

  3. IDENTIFIKASI ANTAGONIS DARI Xanthomonas campestris YANG DIISOLASI DARI RHIZOSPHERE PERKEBUNAN BROKOLI (Brassica oleracea var. italica DI DESA KEMBANG MERTA, KABUPATEN TABANAN, BALI

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    Nadya Treesna Wulansari

    2015-08-01

    Full Text Available The main objectives of this research were to isolate and identify antagonists of Xanthomonas campestris from rhizosphere zone of broccoli plants. Soil samples were collected from broccoli farm located at Kembang Merta village, Tabanan, Bali. Isolation and identification of the antagonists were conducted at the Laboratory of Microbiology, Udayana University. Two fungal (Trichoderma harzianum and  Trichoderma viride and two bacterial (Bacillus sp. and Pseudomonas sp. antagonists potentially to be developed as biocontrol agents of Xanthomonas campestris were successfully identified in this research.

  4. Virulence and immunity orchestrated by the global gene regulator sigL in Mycobacterium avium subsp. paratuberculosis.

    Science.gov (United States)

    Ghosh, Pallab; Steinberg, Howard; Talaat, Adel M

    2014-07-01

    Mycobacterium avium subsp. paratuberculosis causes Johne's disease in ruminants, a chronic enteric disease responsible for severe economic losses in the dairy industry. Global gene regulators, including sigma factors are important in regulating mycobacterial virulence. However, the biological significance of such regulators in M. avium subsp. paratuberculosis rremains elusive. To better decipher the role of sigma factors in M. avium subsp. paratuberculosis pathogenesis, we targeted a key sigma factor gene, sigL, activated in mycobacterium-infected macrophages. We interrogated an M. avium subsp. paratuberculosis ΔsigL mutant against a selected list of stressors that mimic the host microenvironments. Our data showed that sigL was important in maintaining bacterial survival under such stress conditions. Survival levels further reflected the inability of the ΔsigL mutant to persist inside the macrophage microenvironments. Additionally, mouse infection studies suggested a substantial role for sigL in M. avium subsp. paratuberculosis virulence, as indicated by the significant attenuation of the ΔsigL-deficient mutant compared to the parental strain. More importantly, when the sigL mutant was tested for its vaccine potential, protective immunity was generated in a vaccine/challenge model of murine paratuberculosis. Overall, our study highlights critical role of sigL in the pathogenesis and immunity of M. avium subsp. paratuberculosis infection, a potential role that could be shared by similar proteins in other intracellular pathogens. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  5. The contribution of Utility-Scale Solar Energy to the global climate regulation and its effects on local ecosystem services

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    Antonella De Marco

    2014-12-01

    Full Text Available One solution to mitigate climate change can be the production of renewable energy. In this context, the aims of this paper are: (1 the identification of local unsuitable areas for the installation of Utility-Scale Solar Energy (USSE in a municipality in southern Italy; (2 the assessment of the effects of their installation on local natural CO2 sequestration and on avoided CO2; and (3 the evaluation of their contribution to the global climate regulation through scenario analysis. Since 2007, 82 authorizations have been obtained for the installation of USSE in the municipality and 42 over 64 already completed have been installed in unsuitable areas. For what concerns the remaining USSE, two short-term scenarios are analysed in order to take into account their contribution in terms of climate regulation service. The first scenario is called Business As Usual with new planned USSE installed by 2014 also in unsuitable areas, and the second one with the new USSE installed only in suitable areas identified in this study. Surprisingly, Scenario 2 is characterized by a reduced natural capacity to sequester CO2 emissions and by a lower contribution of vegetation in providing the ecosystem service climate regulation in comparison with Scenario 1.

  6. Virulence and Immunity Orchestrated by the Global Gene Regulator sigL in Mycobacterium avium subsp. paratuberculosis

    Science.gov (United States)

    Ghosh, Pallab; Steinberg, Howard

    2014-01-01

    Mycobacterium avium subsp. paratuberculosis causes Johne's disease in ruminants, a chronic enteric disease responsible for severe economic losses in the dairy industry. Global gene regulators, including sigma factors are important in regulating mycobacterial virulence. However, the biological significance of such regulators in M. avium subsp. paratuberculosis rremains elusive. To better decipher the role of sigma factors in M. avium subsp. paratuberculosis pathogenesis, we targeted a key sigma factor gene, sigL, activated in mycobacterium-infected macrophages. We interrogated an M. avium subsp. paratuberculosis ΔsigL mutant against a selected list of stressors that mimic the host microenvironments. Our data showed that sigL was important in maintaining bacterial survival under such stress conditions. Survival levels further reflected the inability of the ΔsigL mutant to persist inside the macrophage microenvironments. Additionally, mouse infection studies suggested a substantial role for sigL in M. avium subsp. paratuberculosis virulence, as indicated by the significant attenuation of the ΔsigL-deficient mutant compared to the parental strain. More importantly, when the sigL mutant was tested for its vaccine potential, protective immunity was generated in a vaccine/challenge model of murine paratuberculosis. Overall, our study highlights critical role of sigL in the pathogenesis and immunity of M. avium subsp. paratuberculosis infection, a potential role that could be shared by similar proteins in other intracellular pathogens. PMID:24799632

  7. CytR Is a Global Positive Regulator of Competence, Type VI Secretion, and Chitinases in Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Samit S Watve

    Full Text Available The facultative pathogen Vibrio cholerae transitions between its human host and aquatic reservoirs where it colonizes chitinous surfaces. Growth on chitin induces expression of chitin utilization genes, genes involved in DNA uptake by natural transformation, and a type VI secretion system that allows contact-dependent killing of neighboring bacteria. We have previously shown that the transcription factor CytR, thought to primarily regulate the pyrimidine nucleoside scavenging response, is required for natural competence in V. cholerae. Through high-throughput RNA sequencing (RNA-seq, we show that CytR positively regulates the majority of competence genes, the three type VI secretion operons, and the four known or predicted chitinases. We used transcriptional reporters and phenotypic analysis to determine the individual contributions of quorum sensing, which is controlled by the transcription factors HapR and QstR; chitin utilization that is mediated by TfoX; and pyrimidine starvation that is orchestrated by CytR, toward each of these processes. We find that in V. cholerae, CytR is a global regulator of multiple behaviors affecting fitness and adaptability in the environment.

  8. Improving acetate tolerance of Escherichia coli by rewiring its global regulator cAMP receptor protein (CRP.

    Directory of Open Access Journals (Sweden)

    Huiqing Chong

    Full Text Available The presence of acetate exceeding 5 g/L is a major concern during E. coli fermentation due to its inhibitory effect on cell growth, thereby limiting high-density cell culture and recombinant protein production. Hence, engineered E. coli strains with enhanced acetate tolerance would be valuable for these bioprocesses. In this work, the acetate tolerance of E. coli was much improved by rewiring its global regulator cAMP receptor protein (CRP, which is reported to regulate 444 genes. Error-prone PCR method was employed to modify crp and the mutagenesis libraries (~3×10(6 were subjected to M9 minimal medium supplemented with 5-10 g/L sodium acetate for selection. Mutant A2 (D138Y was isolated and its growth rate in 15 g/L sodium acetate was found to be 0.083 h(-1, much higher than that of the control (0.016 h(-1. Real-time PCR analysis via OpenArray(® system revealed that over 400 CRP-regulated genes were differentially expressed in A2 with or without acetate stress, including those involved in the TCA cycle, phosphotransferase system, etc. Eight genes were chosen for overexpression and the overexpression of uxaB was found to lead to E. coli acetate sensitivity.

  9. Chemical composition, vasorelaxant, antioxidant and antiplatelet effects of essential oil of Artemisia campestris L. from Oriental Morocco.

    Science.gov (United States)

    Dib, Ikram; Fauconnier, Marie-Laure; Sindic, Marianne; Belmekki, Fatima; Assaidi, Asmae; Berrabah, Mohamed; Mekhfi, Hassane; Aziz, Mohammed; Legssyer, Abdelkhaleq; Bnouham, Mohamed; Ziyyat, Abderrahim

    2017-01-31

    Artemisia campestris L. (Asteraceae) is a medicinal herb traditionally used to treat hypertension and many other diseases. Hence, this study is aimed to analyze the essential oil of A. campestris L (AcEO) and to investigate the antiplatelet, antioxidant effects and the mechanisms of its vasorelaxant effect. The chemical composition of AcEO was elucidated using GC/MS analysis. Then, the antioxidant effect was tested on DPPH radical scavenging and on the prevention of β-carotene bleaching. The antiplatelet effect was performed on the presence of the platelet agonists: thrombin and ADP. The mechanism of action of the vasorelaxant effect was studied by using the cellular blockers specified to explore the involvement of NO/GC pathway and in the presence of calcium channels blockers and potassium channels blockers. AcEO is predominated by the volatiles: spathulenol, ß-eudesmol and p-cymene. The maximal antioxidant effect was obtained with the dose 2 mg/ml of AcEO. The dose 1 mg/ml of AcEO showed a maximum antiplatelet effect of, respectively 49.73% ±9.54 and 48.20% ±8.49 on thrombin and ADP. The vasorelaxation seems not to be mediated via NOS/GC pathway neither via the potassium channels. However, pretreatment with calcium channels blockers attenuated this effect, suggesting that the vasorelaxation is mediated via inhibition of L-type Ca 2+ channels and the activation of SERCA pumps of reticulum plasma. This study confirms the antioxidant, antiplatelet and vasorelaxant effects of A.campestris L essential oil. However, the antihypertensive use of this oil should be further confirmed by the chemical fractionation and subsequent bio-guided assays.

  10. AsnB, regulated by diffusible signal factor and global regulator Clp, is involved in aspartate metabolism, resistance to oxidative stress and virulence in Xanthomonas oryzae pv. oryzicola.

    Science.gov (United States)

    Qian, Guoliang; Liu, Chunhui; Wu, Guichun; Yin, Fangqun; Zhao, Yancun; Zhou, Yijing; Zhang, Yanbing; Song, Zhiwei; Fan, Jiaqin; Hu, Baishi; Liu, Fengquan

    2013-02-01

    Xanthomonas oryzae pv. oryzicola (Xoc) causes bacterial leaf streak in rice, which is a destructive disease worldwide. Xoc virulence factors are regulated by diffusible signal factor (DSF) and the global regulator Clp. In this study, we have demonstrated that asnB (XOC_3054), encoding an asparagine synthetase, is a novel virulence-related gene regulated by both DSF and Clp in Xoc. A sequence analysis revealed that AsnB is highly conserved in Xanthomonas. An asnB mutation in Xoc dramatically impaired pathogen virulence and growth rate in host rice, but did not affect the ability to trigger the hypersensitive response in nonhost (plant) tobacco. Compared with the wild-type strain, the asnB deletion mutant was unable to grow in basic MMX (-) medium (a minimal medium without ammonium sulphate as the nitrogen source) with or without 10 tested nitrogen sources, except asparagine. The disruption of asnB impaired pathogen resistance to oxidative stress and reduced the transcriptional expression of oxyR, katA and katG, which encode three important proteins responsible for hydrogen peroxide (H(2)O(2)) sensing and detoxification in Xanthomonas in the presence of H(2)O(2), and nine important known Xoc virulence-related genes in plant cell-mimicking medium. Furthermore, the asnB mutation did not affect extracellular protease activity, extracellular polysaccharide production, motility or chemotaxis. Taken together, our results demonstrate the role of asnB in Xanthomonas for the first time. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  11. Global regulation of gene expression in response to cysteine availability in Clostridium perfringens

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    André Gaelle

    2010-09-01

    Full Text Available Abstract Background Cysteine has a crucial role in cellular physiology and its synthesis is tightly controlled due to its reactivity. However, little is known about the sulfur metabolism and its regulation in clostridia compared with other firmicutes. In Clostridium perfringens, the two-component system, VirR/VirS, controls the expression of the ubiG operon involved in methionine to cysteine conversion in addition to the expression of several toxin genes. The existence of links between the C. perfringens virulence regulon and sulfur metabolism prompted us to analyze this metabolism in more detail. Results We first performed a tentative reconstruction of sulfur metabolism in C. perfringens and correlated these data with the growth of strain 13 in the presence of various sulfur sources. Surprisingly, C. perfringens can convert cysteine to methionine by an atypical still uncharacterized pathway. We further compared the expression profiles of strain 13 after growth in the presence of cystine or homocysteine that corresponds to conditions of cysteine depletion. Among the 177 genes differentially expressed, we found genes involved in sulfur metabolism and controlled by premature termination of transcription via a cysteine specific T-box system (cysK-cysE, cysP1 and cysP2 or an S-box riboswitch (metK and metT. We also showed that the ubiG operon was submitted to a triple regulation by cysteine availability via a T-box system, by the VirR/VirS system via the VR-RNA and by the VirX regulatory RNA. In addition, we found that expression of pfoA (theta-toxin, nagL (one of the five genes encoding hyaluronidases and genes involved in the maintenance of cell redox status was differentially expressed in response to cysteine availability. Finally, we showed that the expression of genes involved in [Fe-S] clusters biogenesis and of the ldh gene encoding the lactate dehydrogenase was induced during cysteine limitation. Conclusion Several key functions for the

  12. Global discovery of erythroid long noncoding RNAs reveals novel regulators of red cell maturation.

    Science.gov (United States)

    Alvarez-Dominguez, Juan R; Hu, Wenqian; Yuan, Bingbing; Shi, Jiahai; Park, Staphany S; Gromatzky, Austin A; van Oudenaarden, Alexander; Lodish, Harvey F

    2014-01-23

    Erythropoiesis is regulated at multiple levels to ensure the proper generation of mature red cells under multiple physiological conditions. To probe the contribution of long noncoding RNAs (lncRNAs) to this process, we examined >1 billion RNA-seq reads of polyadenylated and nonpolyadenylated RNA from differentiating mouse fetal liver red blood cells and identified 655 lncRNA genes including not only intergenic, antisense, and intronic but also pseudogene and enhancer loci. More than 100 of these genes are previously unrecognized and highly erythroid specific. By integrating genome-wide surveys of chromatin states, transcription factor occupancy, and tissue expression patterns, we identify multiple lncRNAs that are dynamically expressed during erythropoiesis, show epigenetic regulation, and are targeted by key erythroid transcription factors GATA1, TAL1, or KLF1. We focus on 12 such candidates and find that they are nuclear-localized and exhibit complex developmental expression patterns. Depleting them severely impaired erythrocyte maturation, inhibiting cell size reduction and subsequent enucleation. One of them, alncRNA-EC7, is transcribed from an enhancer and is specifically needed for activation of the neighboring gene encoding BAND 3. Our study provides an annotated catalog of erythroid lncRNAs, readily available through an online resource, and shows that diverse types of lncRNAs participate in the regulatory circuitry underlying erythropoiesis.

  13. Salacia campestris root bark extract: peroxidase inhibition, antioxidant and antiradical profile

    Directory of Open Access Journals (Sweden)

    José Carlos Rebuglio Vellosa

    2009-03-01

    Full Text Available Reactive oxygen species (ROS and free radical species have been implicated in initiating or accompanying many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Salacia species have long been used, in several countries, as traditional medicines against certain diseases and for their anti-inflammatory properties. In this study, Salacia campestris Walp (Hippocrateaceae root bark ethanol extract (ScEtOH was assessed for its ability to scavenge free radicals and reactive oxygen species; the results were expressed as percentage inhibition of the active species. ScEtOH was efficient against studied species: DPPH radical (obtained inhibition = 30%, ABTS•+ (IC50 = 1.8±0.8 μg/mL, HOCl (IC50 = 1.7 ± 0.1 μg/mL, O2•- (obtained inhibition = 32%, and NO• (obtained inhibition = 18 %. Peroxidase activity inhibition was evaluated through the guaiacol oxidation reaction catalyzed by hemin, HRP and myeloperoxidase (MPO; data showed that ScEtOH at 10 μg/mL led to 54 and 51% of inhibition, respectively, for the hemin and HRP systems. In the MPO system, ScEtOH promoted a 50% inhibition at 8.9 μg/mL, whereas quercetin, a powerful MPO inhibitor, inhibited this system at 1.35 μg/mL.Espécies reativas do oxigênio (ERO e radicais livres estão relacionados ao início ou à exacerbação de muitas doenças em organismos vivos; existindo portanto uma necessidade contínua por moléculas antioxidantes que inativem as ERO e radicais livres. Muitos estudos com extratos brutos de plantas têm demonstrado propriedades antioxidantes e seqüestradoras de radicais livres. Espécies de Salacia são utilizadas, em muitos países, como remédio tradicional contra certas doenças e por suas propriedades antiinflamatórias. Neste estudo, o extrato bruto etanólico da casca da raiz da Salacia

  14. A Flexible Binding Site Architecture Provides New Insights into CcpA Global Regulation in Gram-Positive Bacteria

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    Yunpeng Yang

    2017-01-01

    Full Text Available Catabolite control protein A (CcpA is the master regulator in Gram-positive bacteria that mediates carbon catabolite repression (CCR and carbon catabolite activation (CCA, two fundamental regulatory mechanisms that enable competitive advantages in carbon catabolism. It is generally regarded that CcpA exerts its regulatory role by binding to a typical 14- to 16-nucleotide (nt consensus site that is called a catabolite response element (cre within the target regions. However, here we report a previously unknown noncanonical flexible architecture of the CcpA-binding site in solventogenic clostridia, providing new mechanistic insights into catabolite regulation. This novel CcpA-binding site, named crevar, has a unique architecture that consists of two inverted repeats and an intervening spacer, all of which are variable in nucleotide composition and length, except for a 6-bp core palindromic sequence (TGTAAA/TTTACA. It was found that the length of the intervening spacer of crevar can affect CcpA binding affinity, and moreover, the core palindromic sequence of crevar is the key structure for regulation. Such a variable architecture of crevar shows potential importance for CcpA’s diverse and fine regulation. A total of 103 potential crevar sites were discovered in solventogenic Clostridium acetobutylicum, of which 42 sites were picked out for electrophoretic mobility shift assays (EMSAs, and 30 sites were confirmed to be bound by CcpA. These 30 crevar sites are associated with 27 genes involved in many important pathways. Also of significance, the crevar sites are found to be widespread and function in a great number of taxonomically different Gram-positive bacteria, including pathogens, suggesting their global role in Gram-positive bacteria.

  15. SUMO modification of Akt regulates global SUMOylation and substrate SUMOylation specificity through Akt phosphorylation of Ubc9 and SUMO1.

    Science.gov (United States)

    Lin, C H; Liu, S Y; Lee, E H Y

    2016-02-04

    SUMOylation is an important post-translational modification, and Akt SUMOylation was found to regulate cell proliferation, tumorigenesis and cell cycle, but the molecular mechanism of Akt SUMOylation is less well known. Here, we show both endogenous and ectopic Akt SUMOylation and Lys276 is the major SUMO acceptor on Akt. Further, Akt SUMOylation is Akt phosphorylation dependent and Akt SUMOylation increases Akt kinase activity without affecting the phosphorylation level of Akt. Moreover, endogenous Akt SUMOylation is enhanced by insulin treatment and this is Akt activity dependent. Heat-shock stimulus also increases Akt SUMOylation and it is also Akt activity dependent. Endogenous Akt SUMOylation is also found in the rat brain and it is enhanced by insulin-like growth factor-1 stimulation. In addition, Akt directly phosphorylates Ubc9 at Thr35 and phosphorylates SUMO1 at Thr76. Ubc9 phosphorylation at Thr35 promotes Ubc9 thioester bond formation and SUMO1 phosphorylation at Thr76 stabilizes the SUMO1 protein. Through these distinct mechanisms, Akt SUMOylation regulates global SUMOylation, including Akt and Ubc9 SUMOylation, and substrate SUMOylation specificity, including STAT1 and CREB SUMOylation, in different manners. Akt SUMOylation also enhances phosphatase and tensin homolog (PTEN) SUMOylation through Akt phosphorylation of Ubc9 and SUMO1, which serves as an endogenous mechanism to stop the positive feedback loop resulted from Akt activation. Further, Akt SUMOylation increases cyclin D1 expression and cell proliferation, and these effects are also mediated through Ubc9 phosphorylation at Thr35 and SUMO1 phosphorylation at Thr76. Here, we have identified a novel mechanism for SUMOylation regulation. Because of the important role Akt plays in tumorigenesis, this mechanism may also be involved in Akt-regulated tumorigenesis.

  16. Improving ethanol tolerance of Escherichia coli by rewiring its global regulator cAMP receptor protein (CRP.

    Directory of Open Access Journals (Sweden)

    Huiqing Chong

    Full Text Available A major challenge in bioethanol fermentation is the low tolerance of the microbial host towards the end product bioethanol. Here we report to improve the ethanol tolerance of E. coli from the transcriptional level by engineering its global transcription factor cAMP receptor protein (CRP, which is known to regulate over 400 genes in E. coli. Three ethanol tolerant CRP mutants (E1- E3 were identified from error-prone PCR libraries. The best ethanol-tolerant strain E2 (M59T had the growth rate of 0.08 h(-1 in 62 g/L ethanol, higher than that of the control at 0.06 h(-1. The M59T mutation was then integrated into the genome to create variant iE2. When exposed to 150 g/l ethanol, the survival of iE2 after 15 min was about 12%, while that of BW25113 was <0.01%. Quantitative real-time reverse transcription PCR analysis (RT-PCR on 444 CRP-regulated genes using OpenArray® technology revealed that 203 genes were differentially expressed in iE2 in the absence of ethanol, whereas 92 displayed differential expression when facing ethanol stress. These genes belong to various functional groups, including central intermediary metabolism (aceE, acnA, sdhD, sucA, iron ion transport (entH, entD, fecA, fecB, and general stress response (osmY, rpoS. Six up-regulated and twelve down-regulated common genes were found in both iE2 and E2 under ethanol stress, whereas over one hundred common genes showed differential expression in the absence of ethanol. Based on the RT-PCR results, entA, marA or bhsA was knocked out in iE2 and the resulting strains became more sensitive towards ethanol.

  17. Mammalian Sir2 homolog SIRT3 regulates global mitochondrial lysine acetylation

    DEFF Research Database (Denmark)

    Lombard, David B; Alt, Frederick W; Cheng, Hwei-Ling

    2007-01-01

    Homologs of the Saccharomyces cerevisiae Sir2 protein, sirtuins, promote longevity in many organisms. Studies of the sirtuin SIRT3 have so far been limited to cell culture systems. Here, we investigate the localization and function of SIRT3 in vivo. We show that endogenous mouse SIRT3 is a soluble...... mitochondrial protein. To address the function and relevance of SIRT3 in the regulation of energy metabolism, we generated and phenotypically characterized SIRT3 knockout mice. SIRT3-deficient animals exhibit striking mitochondrial protein hyperacetylation, suggesting that SIRT3 is a major mitochondrial...... deacetylase. In contrast, no mitochondrial hyperacetylation was detectable in mice lacking the two other mitochondrial sirtuins, SIRT4 and SIRT5. Surprisingly, despite this biochemical phenotype, SIRT3-deficient mice are metabolically unremarkable under basal conditions and show normal adaptive thermogenesis...

  18. Global harmonization of food safety regulations: perspectives from Japan after the Fukushima nuclear accident.

    Science.gov (United States)

    Yoshida, Mitsuru

    2014-08-01

    Japanese food self-sufficiency was only 39% on the basis of kcal in 2012, so Japan relies heavily on imported food. Hence the necessity of having international rules on the regulation of food contaminants is important especially for countries like Japan that depend on food imports. A One-Stop-Testing system is desired, in which the test result obtained from a single testing laboratory is accepted as valid worldwide. To establish this system, laboratory accreditation under international standards is a necessary step. Furthermore, the importance of supply of reference materials for internal quality control and proficiency testing for external quality control of each laboratory's analytical system is reviewed in connection with the experience of radioactive nuclide contamination resulting from the Fukushima nuclear power plant accident in March 2011. © 2013 Society of Chemical Industry.

  19. GERMINATION TEST IN SEEDS OF MELOTHRIA CAMPESTRIS (NAUDIN H. SCHAEF. & S.S. RENNER

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    ANA CARINA DA SILVA CÂNDIDO

    2016-01-01

    Full Text Available The Cerrado occupies 25% of the Brazilian territory and is the second largest biome in South America, second only to the Amazon Rainforest. Hence, studies on the native species of the Cerrado are important for implementing conservation strategies. In this context, knowledge of the requirements and conditions for germination of seeds of these native species is essential. The Cerrado watermelon ( Melothria campestris (Naudin H. Schaef. & S.S. Renner is a plant that is not cultivated, but has been used in revegetation projects in the countryside of the Cerrado because its fruits are fed upon by fauna in times of food shortage. The purpose of this study was to determine the most appropriate methodology for the germination of the Cerrado watermelon, by identifying the best - suited substrate, the optimal temperature, and the corresponding time taken for germination . The treatments consisted of four substrates: in a paper roll, on paper, in sand, and on sand; and four temperatures: 20, 25, and 30 °C (maintained constant, and a fourth temperature treatment that alternated 20 - 30 °C. The effect of the substrates and temperatures on seed performance was evaluated using the germination test, speed index, and average time for germination. The experimental design was fully randomized, with treatments distributed in a 4 × 4 (substrates × temperatures factorial scheme, with four replications. Our results show that the temperature of 20 °C had a negative influence on germination in all substrates. Further, we found that the germination of the Cerrado watermelon seeds was best in a paper roll or on sand substrate, maintained at a constant temperature of 30 °C, or when temperature was alternated 20 - 30 °C, and the time required for germination stabilization was 30 days.

  20. Genotipos de frijol (Phaseolus Vulgaris l. resistentes a Xanthomonas campestris pv. phaseoli de Mexico

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    Rosa Navarrete

    2000-01-01

    Full Text Available Genotipos de frijol (Phaseolus vulgaris L. resistentes a Xanthomonas campestris pv. phaseoli de México. Durante 1995 se evaluó la reacción de genotipos de frijol de diversos origenes a Xcp, bajo condiciones de invernadero en el Campo Experimental del Valle de México, del INIFAP. Se realizaron tres experimentos con a120, b44 y csiete genotipos de frijol. Las plantas se inocularon por corte con navajas en la etapa V3, a y b con una mezcla de nueve cepas de Xcp y el c, con cada una de siete cepas con diferente grado de patogenicidad. La severidad se evaluó 20 días después de la inoculación, por comparación con una escala visual de nueve grados. Los datos se analizaron bajo un diseño completamente al azar. En a, los genotipos que mostraron reacción de resistencia a Xcp fueron: A 36, A 475, G 5686, G 11867, Harowood, SEA 14, XAN 266, MCD 4012 y REN 27. En b los genotipos resistentes fueron: Sequía Durango, Taylor y XAN 30. En los experimentos anteriores la severidad de la enfermedad mostró una distribución normal, con el máximo número de genotipos en el grado de severidad cinco en a y seis en b. Los resultados obtenidos indican que el uso de mezclas de cepas de bacterias con diferente patogenicidad es eficiente para identificar genotipos de frijol resistentes a Xcp. Los genotipos resistentes identificados en el último experimento, mostraron respuesta diferencial e interacciones genotipo por cepa. REN 27 y SEA 14 mostraron resistencia a las cepas utilizadas

  1. African perspectives on the need for global harmonisation of food safety regulations.

    Science.gov (United States)

    Anelich, Lucia E C M

    2014-08-01

    Africa is a large continent consisting of 54 countries at different levels of development and reflecting numerous diverse cultures. Africa's agricultural potential is largely untapped, with approximately 60% of the world's non-cultivated arable land found in sub-Saharan Africa. Excluding South Africa, which is the largest economy in Africa and which has a well-established food sector with a substantial export market, economies in sub-Saharan Africa have been steadily growing at over 5% per annum. Whilst most African countries face many challenges, including weak infrastructure as well as political and economic instability, many changes are occurring, one of these being identifying specific commodities in a particular country which warrant substantial investment for growth into export opportunities. These opportunities create an immediate need for development of food standards, including food safety standards, based on scientific principles to enable regional and international trade in food, thereby assisting in ensuring Africa's role in the global food economy. © 2013 Society of Chemical Industry.

  2. Análisis comparativo de los caracteres epidérmicos en Flourensia campestris y F. oolepis (Asteraceae Comparative analysis of the epidermal characters in Flourensia campestris and F. oolepis (Asteraceae

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    Natalia Delbón

    Full Text Available En el presente estudio se examinaron y compararon cuantitativamente las epidermis foliares de Flourensia campestris Griseb. y F. oolepis S. F. Blake, especies endémicas que crecen en las sierras de Córdoba, Argentina. Para ello, se seleccionaron cinco variables: número de células epidérmicas propiamente dichas, estomas, tricomas glandulares y eglandulares e índice estomático. Los resultados obtenidos se evaluaron por métodos estadísticos; ellos indican que hay diferencias significativas entre ambas especies en las variables frecuencia de estomas, de células propiamente dichas, de tricomas glandulares e índice estomático. Estos datos podrían ser de interés para su reconocimiento cuando se dispone de muestras pequeñas o fragmentos.This study provides comparative analyses of foliar epidermis in Flourensia campestris Griseb. and F. oolepis S. F. Blake, endemic species that grow in Córdoba, Argentina. Five variables were selected: number of epidermal cells, stomata, glandular and eglandular trichomes and stomatal index. Results were evaluated by statistical methods; they show that there are significant differences between the variables of both species; these data could be of interest for their identification, when only are available small samples and fragments.

  3. High-resolution detection of DNA binding sites of the global transcriptional regulator GlxR in Corynebacterium glutamicum

    DEFF Research Database (Denmark)

    Jungwirth, Britta; Sala, Claudia; Kohl, Thomas A

    2013-01-01

    The transcriptional regulator GlxR has been characterized as a global hub within the gene-regulatory network of Corynebacterium glutamicum. Chromatin immunoprecipitation with a specific anti-GlxR antibody and subsequent high-throughput sequencing (ChIP-seq) was applied to C. glutamicum to get new...... in vivo insights into the gene composition of the GlxR regulon. In a comparative approach, C. glutamicum cells were grown with either glucose or acetate as the sole carbon source prior to immunoprecipitation. High-throughput sequencing resulted in 69 million reads and 2.6 Gb of genomic information. After...... mapping of these data on the genome sequence of C. glutamicum, 107 enriched DNA fragments were detected from cells grown with glucose as carbon source. GlxR binding sites were identified in the sequence of 79 enriched DNA fragments, of which 21 sites were not previously reported. Electrophoretic mobility...

  4. Role of Corynebacterium glutamicum sprA encoding a serine protease in glxR-mediated global gene regulation.

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    Eun-Ji Hong

    Full Text Available The global regulator glxR of Corynebacterium glutamicum is involved in many cellular activities. Considering its role, the GlxR protein likely interacts with other proteins to obtain, maintain, and control its activity. To isolate proteins interacting with GlxR, we used a two-hybrid system with GlxR as the bait. Subsequently, the partner, a subtilisin-like serine protease, was isolated from a C. glutamicum genomic library. Unlike glxR, which showed constitutive expression, the expression of sprA, encoding a serine protease, was maximal in the log phase. Purified His6-SprA protein underwent self-proteolysis and proteolyzed purified GlxR. The proteolytic action of SprA on GlxR was not observed in the presence of cyclic adenosine monophosphate, which modulates GlxR activity. The C. glutamicum sprA deletion mutant (ΔsprA and sprA-overexpressing (P180-sprA strains showed reduced growth. The activity of isocitrate dehydrogenase (a tricarboxylic acid cycle enzyme in these strains decreased to 30-50% of that in the wild-type strain. In the P180-sprA strain, proteins involved in diverse cellular functions such as energy and carbon metabolism (NCgl2809, nitrogen metabolism (NCgl0049, methylation reactions (NCgl0719, and peptidoglycan biosynthesis (NCgl1267, as well as stress, starvation, and survival (NCgl0938 were affected and showed decreased transcription. Taken together, these data suggest that SprA, as a serine protease, performs a novel regulatory role not only in glxR-mediated gene expression but also in other areas of cell physiology. In addition, the tight control of SprA and GlxR availability may indicate their importance in global gene regulation.

  5. Global regulation of the response to sulfur availability in the cheese-related bacterium Brevibacterium aurantiacum.

    Science.gov (United States)

    Forquin, Marie-Pierre; Hébert, Agnès; Roux, Aurélie; Aubert, Julie; Proux, Caroline; Heilier, Jean-François; Landaud, Sophie; Junot, Christophe; Bonnarme, Pascal; Martin-Verstraete, Isabelle

    2011-02-01

    In this study, we combined metabolic reconstruction, growth assays, and metabolome and transcriptome analyses to obtain a global view of the sulfur metabolic network and of the response to sulfur availability in Brevibacterium aurantiacum. In agreement with the growth of B. aurantiacum in the presence of sulfate and cystine, the metabolic reconstruction showed the presence of a sulfate assimilation pathway, thiolation pathways that produce cysteine (cysE and cysK) or homocysteine (metX and metY) from sulfide, at least one gene of the transsulfuration pathway (aecD), and genes encoding three MetE-type methionine synthases. We also compared the expression profiles of B. aurantiacum ATCC 9175 during sulfur starvation or in the presence of sulfate. Under sulfur starvation, 690 genes, including 21 genes involved in sulfur metabolism and 29 genes encoding amino acids and peptide transporters, were differentially expressed. We also investigated changes in pools of sulfur-containing metabolites and in expression profiles after growth in the presence of sulfate, cystine, or methionine plus cystine. The expression of genes involved in sulfate assimilation and cysteine synthesis was repressed in the presence of cystine, whereas the expression of metX, metY, metE1, metE2, and BL613, encoding a probable cystathionine-γ-synthase, decreased in the presence of methionine. We identified three ABC transporters: two operons encoding transporters were transcribed more strongly during cysteine limitation, and one was transcribed more strongly during methionine depletion. Finally, the expression of genes encoding a methionine γ-lyase (BL929) and a methionine transporter (metPS) was induced in the presence of methionine in conjunction with a significant increase in volatile sulfur compound production.

  6. Post-transcriptional regulation on a global scale: form and function of Csr/Rsm systems.

    Science.gov (United States)

    Romeo, Tony; Vakulskas, Christopher A; Babitzke, Paul

    2013-02-01

    Originally described as a repressor of gene expression in the stationary phase of growth, CsrA (RsmA) regulates primary and secondary metabolic pathways, biofilm formation, motility, virulence circuitry of pathogens, quorum sensing and stress response systems by binding to conserved sequences in its target mRNAs and altering their translation and/or turnover. While the binding of CsrA to RNA is understood at an atomic level, new mechanisms of gene activation and repression by this protein are still emerging. In the γ-proteobacteria, small non-coding RNAs (sRNAs) use molecular mimicry to sequester multiple CsrA dimers away from mRNA. In contrast, the FliW protein of Bacillus subtilis inhibits CsrA activity by binding to this protein, thereby establishing a checkpoint in flagellum morphogenesis. Turnover of CsrB and CsrC sRNAs in Escherichia coli requires a specificity protein of the GGDEF-EAL domain superfamily, CsrD, in addition to the housekeeping nucleases RNase E and PNPase. The Csr system of E. coli contains extensive autoregulatory circuitry, which governs the expression and activity of CsrA. Interaction of the Csr system with transcriptional regulatory networks results in a variety of complex response patterns. This minireview will highlight basic principles and new insights into the workings of these complex eubacterial regulatory systems. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  7. The Xanthomonas campestris type III effector XopJ targets the host cell proteasome to suppress salicylic-acid mediated plant defence.

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    Suayib Üstün

    Full Text Available The phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv requires type III effector proteins (T3Es for virulence. After translocation into the host cell, T3Es are thought to interact with components of host immunity to suppress defence responses. XopJ is a T3E protein from Xcv that interferes with plant immune responses; however, its host cellular target is unknown. Here we show that XopJ interacts with the proteasomal subunit RPT6 in yeast and in planta to inhibit proteasome activity. A C235A mutation within the catalytic triad of XopJ as well as a G2A exchange within the N-terminal myristoylation motif abolishes the ability of XopJ to inhibit the proteasome. Xcv ΔxopJ mutants are impaired in growth and display accelerated symptom development including tissue necrosis on susceptible pepper leaves. Application of the proteasome inhibitor MG132 restored the ability of the Xcv ΔxopJ to attenuate the development of leaf necrosis. The XopJ dependent delay of tissue degeneration correlates with reduced levels of salicylic acid (SA and changes in defence- and senescence-associated gene expression. Necrosis upon infection with Xcv ΔxopJ was greatly reduced in pepper plants with reduced expression of NPR1, a central regulator of SA responses, demonstrating the involvement of SA-signalling in the development of XopJ dependent phenotypes. Our results suggest that XopJ-mediated inhibition of the proteasome interferes with SA-dependent defence response to attenuate onset of necrosis and to alter host transcription. A central role of the proteasome in plant defence is discussed.

  8. NLRP3 Inflammasome Activation in the Brain after Global Cerebral Ischemia and Regulation by 17β-Estradiol

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    Roshni Thakkar

    2016-01-01

    Full Text Available 17β-Estradiol (E2 is a well-known neuroprotective factor in the brain. Recently, our lab demonstrated that the neuroprotective and cognitive effects of E2 require mediation by the estrogen receptor (ER coregulator protein and proline-, glutamic acid-, and leucine-rich protein 1 (PELP1. In the current study, we examined whether E2, acting via PELP1, can exert anti-inflammatory effects in the ovariectomized rat and mouse hippocampus to regulate NLRP3 inflammasome activation after global cerebral ischemia (GCI. Activation of the NLRP3 inflammasome pathway and expression of its downstream products, cleaved caspase-1 and IL-1β, were robustly increased in the hippocampus after GCI, with peak levels observed at 6-7 days. Expression of P2X7 receptor, an upstream regulator of NLRP3, was also increased after GCI. E2 markedly inhibited NLRP3 inflammasome pathway activation, caspase-1, and proinflammatory cytokine production, as well as P2X7 receptor expression after GCI (at both the mRNA and protein level. Intriguingly, the ability of E2 to exert these anti-inflammatory effects was lost in PELP1 forebrain-specific knockout mice, indicating a key role for PELP1 in E2 anti-inflammatory signaling. Collectively, our study demonstrates that NLRP3 inflammasome activation and proinflammatory cytokine production are markedly increased in the hippocampus after GCI, and that E2 signaling via PELP1 can profoundly inhibit these proinflammatory effects.

  9. The miR-17∼92 microRNA Cluster Is a Global Regulator of Tumor Metabolism

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    Said Izreig

    2016-08-01

    Full Text Available A central hallmark of cancer cells is the reprogramming of cellular metabolism to meet the bioenergetic and biosynthetic demands of malignant growth. Here, we report that the miR-17∼92 microRNA (miRNA cluster is an oncogenic driver of tumor metabolic reprogramming. Loss of miR-17∼92 in Myc+ tumor cells leads to a global decrease in tumor cell metabolism, affecting both glycolytic and mitochondrial metabolism, whereas increased miR-17∼92 expression is sufficient to drive increased nutrient usage by tumor cells. We mapped the metabolic control element of miR-17∼92 to the miR-17 seed family, which influences cellular metabolism and mammalian target of rapamycin complex 1 (mTORC1 signaling through negative regulation of the LKB1 tumor suppressor. miR-17-dependent tuning of LKB1 levels regulates both the metabolic potential of Myc+ lymphomas and tumor growth in vivo. Our results establish metabolic reprogramming as a central function of the oncogenic miR-17∼92 miRNA cluster that drives the progression of MYC-dependent tumors.

  10. Involvement of tonB-exbBD1D2 operon in infection of Xanthomonas campestris phage phi L7.

    Science.gov (United States)

    Hung, Chih-Hsin; Yang, Chi-Fan; Yang, Chiou-Ying; Tseng, Yi-Hsiung

    2003-03-21

    phi L7 is a lytic bacteriophage infecting Xanthomonas campestris pv. campestris, a Gram-negative bacterium producing xanthan gum and causing black rot in crucifers. A mutant resistant to phi L7 was isolated by Tn5 mutagenesis. Sequence analysis indicated that the gene responsible for the mutation is tonB encoding an inner membrane protein previously shown to be required for iron uptake and pathogenesis. This gene is clustered with three other genes, tonB-exbB-exbD1-exbD2. Results of insertional mutations, DNA and protein sequence analyses, phage sensitivity tests, transfection tests, complementation tests, and phage adsorption assays together with the cellular location of the proteins indicate that TonB, ExbB, and ExbD1 are essential for penetration of phage phi L7. The genome organization, structural features of the tonB-exb region, and transcriptional analyses including Northern hybridization, reporter assays, and primer extension together indicate that the four genes are organized into an operon.

  11. Cloning, crystallization and preliminary X-ray study of XC1258, a CN-hydrolase superfamily protein from Xanthomonas campestris

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Ying-Der; Chin, Ko-Hsin [Institute of Biochemistry, National Chung-Hsing University, Taichung 40227,Taiwan (China); Shr, Hui-Lin [Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei,Taiwan (China); Core Facility for Protein Crystallography, Academia Sinica, Nankang, Taipei,Taiwan (China); Gao, Fei Philip [National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310 (United States); Lyu, Ping-Chiang [Department of Life Science, National Tsing Hua University, Hsin-Chu,Taiwan (China); Wang, Andrew H.-J. [Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei,Taiwan (China); Core Facility for Protein Crystallography, Academia Sinica, Nankang, Taipei,Taiwan (China); Chou, Shan-Ho, E-mail: shchou@nchu.edu.tw [Institute of Biochemistry, National Chung-Hsing University, Taichung 40227,Taiwan (China)

    2006-10-01

    A CN-hydrolase superfamily protein from the plant pathogen X. campestris has been overexpressed in E. coli, purified and crystallized. CN-hydrolase superfamily proteins are involved in a wide variety of non-peptide carbon–nitrogen hydrolysis reactions, producing some important natural products such as auxin, biotin, precursors of antibiotics etc. These reactions all involve attack on a cyano or carbonyl carbon by a conserved novel catalytic triad Glu-Lys-Cys through a thiol acylenzyme intermediate. However, classification into the CN-hydrolase superfamily based on sequence similarity alone is not straightforward and further structural data are necessary to improve this categorization. Here, the cloning, expression, crystallization and preliminary X-ray analysis of XC1258, a CN-hydrolase superfamily protein from the plant pathogen Xanthomonas campestris (Xcc), are reported. The SeMet-substituted XC1258 crystals diffracted to a resolution of 1.73 Å. They are orthorhombic and belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 143.8, b = 154.63, c = 51.3 Å, respectively.

  12. Protective effects of aqueous extract of Artemisia campestris against puffer fish Lagocephalus lagocephalus extract-induced oxidative damage in rats.

    Science.gov (United States)

    Saoudi, Mongi; Allagui, Mohamed Salah; Abdelmouleh, Abdelwaheb; Jamoussi, Kamel; El Feki, Abdelfattah

    2010-11-01

    The aerial parts of Artemisia campestris are often used in Tunisian poisoning cases and are known to possess significant antioxidant activities. The objective of this study is to evaluate the protective effects of an aqueous extract (5g/l) of A. campestris leaves and stems (AE), on oxidative damages induced by liver extract (LT) from poisonous fish Lagocephalus lagocephalus in Wistar rats. AE was found to contain large amounts of K(+), Na(+), Ca(++) and significant antioxidant capacities highlighted by high level of polyphenols and scavenging activities for DPPH and superoxide anion. LT-injected rats (1ml/100g body wt) for 10 days showed (1) a reduced appetite and diarrhea resulting in a lower growth rate than controls, (2) a decrease in serum ALT and AST activities suggesting liver functional disorders, (3) an increase of serum urea and creatinine and reduced serum sodium and potassium concentrations highlighting renal insufficiency and (4) an oxidative stress as evidenced by the raise of TBARS and the inhibition of SOD, CAT and GSH-Px activities in liver, kidney and brain tissues Absorption of AE as a drink, for 20 days (10 pre-treatment days+10 experiment days) did not lead significant change of studied parameters but prevented all the disorders induced by LT. Copyright © 2009 Elsevier GmbH. All rights reserved.

  13. Evaluation of in vitro anticancer activity of Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris.

    Science.gov (United States)

    Behbahani, Mandana

    2014-01-01

    The present investigation was carried out to study the relationship between presence of cytotoxic compounds in Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris. The cytotoxic activity of the pure compounds was performed by MTT assay against breast cancer cell lines (MCF-7 and MDA-MB-231) and normal breast cell line (MCF 10A). The induction of apoptosis was measured by the expression levels of p53, bcl-2, bax and caspase-3 genes using quantitative Real Time PCR. Three active fractions were detected by nuclear magnetic resonance as lutein, lupeol and eugenol, respectively, in C. officinalis, A. maurorum and O. basilicum. These compounds and their epoxidized forms were also detected in their parasite C. campestris. The cytotoxic activity of lutein epoxide, lupeol epoxide and eugenol epoxide was significantly more than lutein, lupeol and eugenol. The mRNA expression level of p53, caspase-3 and bax genes were increased in both cancer cells treated with all pure compounds. However, bcl-2 gene expression decreased in treated breast cancer cells. In conclusion, all the data indicated that the epoxide forms of lupeol, lutein and eugenol are potential drug candidates for inducing apoptosis in human breast cancer cells.

  14. Evaluation of in vitro anticancer activity of Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris.

    Directory of Open Access Journals (Sweden)

    Mandana Behbahani

    Full Text Available The present investigation was carried out to study the relationship between presence of cytotoxic compounds in Ocimum basilicum, Alhagi maurorum, Calendula officinalis and their parasite Cuscuta campestris. The cytotoxic activity of the pure compounds was performed by MTT assay against breast cancer cell lines (MCF-7 and MDA-MB-231 and normal breast cell line (MCF 10A. The induction of apoptosis was measured by the expression levels of p53, bcl-2, bax and caspase-3 genes using quantitative Real Time PCR. Three active fractions were detected by nuclear magnetic resonance as lutein, lupeol and eugenol, respectively, in C. officinalis, A. maurorum and O. basilicum. These compounds and their epoxidized forms were also detected in their parasite C. campestris. The cytotoxic activity of lutein epoxide, lupeol epoxide and eugenol epoxide was significantly more than lutein, lupeol and eugenol. The mRNA expression level of p53, caspase-3 and bax genes were increased in both cancer cells treated with all pure compounds. However, bcl-2 gene expression decreased in treated breast cancer cells. In conclusion, all the data indicated that the epoxide forms of lupeol, lutein and eugenol are potential drug candidates for inducing apoptosis in human breast cancer cells.

  15. Detection and identification of phytopathogenic Xanthomonas strains by amplification of DNA sequences related to the hrp genes of Xanthomonas campestris pv. vesicatoria.

    Science.gov (United States)

    Leite, R P; Minsavage, G V; Bonas, U; Stall, R E

    1994-04-01

    Three pairs of oligonucleotide primers specific for different regions of the hrp gene (hypersensitive reaction and pathogenicity) cluster of Xanthomonas campestris pv. vesicatoria were designed and tested for amplification of DNA isolated from a large number of different bacteria. DNA sequences related to the hrp genes were successfully amplified from X. fragariae and from 28 pathovars of X. campestris. No DNA amplification occurred with genomic DNA from phytopathogenic strains of X. campestris pv. secalis, X. campestris pv. translucens, and X. albilineans or from nonpathogenic opportunistic xanthomonads and phytopathogenic strains of the genera Acidovorax, Agrobacterium, Clavibacter, Erwinia, Pseudomonas, and Xylella. The DNA from those bacteria also failed to hybridize to hrp-specific fragments in Southern blot analysis. DNA fragments amplified with a particular primer pair were of identical size from each of the different phytopathogenic xanthomonads. However, restriction analysis of these fragments by using frequently cutting endonucleases revealed variation in the pattern for these hrp-related fragments amplified from the different Xanthomonas strains. The restriction patterns generated for the different fragments allowed distinction of the strains representing a pathovar or species of phytopathogenic xanthomonads. We believe that DNA amplification with hrp-specific oligonucleotide primers is a highly sensitive and specific method that can be applied for detection and identification of phytopathogenic xanthomonads.

  16. Expression of the alaE gene is positively regulated by the global regulator Lrp in response to intracellular accumulation of l-alanine in Escherichia coli.

    Science.gov (United States)

    Ihara, Kohei; Sato, Kazuki; Hori, Hatsuhiro; Makino, Yumiko; Shigenobu, Shuji; Ando, Tasuke; Isogai, Emiko; Yoneyama, Hiroshi

    2017-04-01

    The alaE gene in Escherichia coli encodes an l-alanine exporter that catalyzes the active export of l-alanine using proton electrochemical potential. In our previous study, alaE expression was shown to increase in the presence of l-alanyl-l-alanine (Ala-Ala). In this study, the global regulator leucine-responsive regulatory protein (Lrp) was identified as an activator of the alaE gene. A promoter less β-galactosidase gene was fused to an alaE upstream region (240 nucleotides). Cells that were lacZ-deficient and harbored this reporter plasmid showed significant induction of β-galactosidase activity (approximately 17-fold) in the presence of 6 mM l-alanine, l-leucine, and Ala-Ala. However, a reporter plasmid possessing a smaller alaE upstream region (180 nucleotides) yielded transformants with strikingly low enzyme activity under the same conditions. In contrast, lrp-deficient cells showed almost no β-galactosidase induction, indicating that Lrp positively regulates alaE expression. We next performed an electrophoretic mobility shift assay (EMSA) and a DNase I footprinting assay using purified hexahistidine-tagged Lrp (Lrp-His). Consequently, we found that Lrp-His binds to the alaE upstream region spanning nucleotide -161 to -83 with a physiologically relevant affinity (apparent K D , 288.7 ± 83.8 nM). Furthermore, the binding affinity of Lrp-His toward its cis-element was increased by l-alanine and l-leucine, but not by Ala-Ala and d-alanine. Based on these results, we concluded that the gene expression of the alaE is regulated by Lrp in response to intracellular levels of l-alanine, which eventually leads to intracellular homeostasis of l-alanine concentrations. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Global regulator SoxR is a negative regulator of efflux pump gene expression and affects antibiotic resistance and fitness in Acinetobacter baumannii.

    Science.gov (United States)

    Li, Henan; Wang, Qi; Wang, Ruobing; Zhang, Yawei; Wang, Xiaojuan; Wang, Hui

    2017-06-01

    SoxR is a global regulator contributing to multidrug resistance in Enterobacteriaceae. However, the contribution of SoxR to antibiotic resistance and fitness in Acinetobacter baumannii has not yet been studied. Comparisons of molecular characteristics were performed between 32 multidrug-resistant A. baumannii isolates and 11 susceptible isolates. A soxR overexpression mutant was constructed, and its resistance phenotype was analyzed. The impact of SoxR on efflux pump gene expression was measured at the transcription level. The effect of SoxR on the growth and fitness of A. baumannii was analyzed using a growth rate assay and an in vitro competition assay. The frequency of the Gly39Ser mutation in soxR was higher in multidrug-resistant A. baumannii, whereas the soxS gene was absent in all strains analyzed. SoxR overexpression led to increased susceptibility to chloramphenicol (4-fold), tetracycline (2-fold), tigecycline (2-fold), ciprofloxacin (2-fold), amikacin (2-fold), and trimethoprim (2-fold), but it did not influence imipenem susceptibility. Decreased expression of abeS (3.8-fold), abeM (1.3-fold), adeJ (2.4-fold), and adeG (2.5-fold) were correlated with soxR overexpression (P baumannii.

  18. Laboratory-evolved mutants of an exogenous global regulator, IrrE from Deinococcus radiodurans, enhance stress tolerances of Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Tingjian Chen

    Full Text Available BACKGROUND: The tolerance of cells toward different stresses is very important for industrial strains of microbes, but difficult to improve by the manipulation of single genes. Traditional methods for enhancing cellular tolerances are inefficient and time-consuming. Recently, approaches employing global transcriptional or translational engineering methods have been increasingly explored. We found that an exogenous global regulator, irrE from an extremely radiation-resistant bacterium, Deinococcus radiodurans, has the potential to act as a global regulator in Escherichia coli, and that laboratory-evolution might be applied to alter this regulator to elicit different phenotypes for E. coli. METHODOLOGY/PRINCIPAL FINDINGS: To extend the methodology for strain improvement and to obtain higher tolerances toward different stresses, we here describe an approach of engineering irrE gene in E. coli. An irrE library was constructed by randomly mutating the gene, and this library was then selected for tolerance to ethanol, butanol and acetate stresses. Several mutants showing significant tolerances were obtained and characterized. The tolerances of E. coli cells containing these mutants were enhanced 2 to 50-fold, based on cell growth tests using different concentrations of alcohols or acetate, and enhanced 10 to 100-fold based on ethanol or butanol shock experiments. Intracellular reactive oxygen species (ROS assays showed that intracellular ROS levels were sharply reduced for cells containing the irrE mutants. Sequence analysis of the mutants revealed that the mutations distribute cross all three domains of the protein. CONCLUSIONS: To our knowledge, this is the first time that an exogenous global regulator has been artificially evolved to suit its new host. The successes suggest the possibility of improving tolerances of industrial strains by introducing and engineering exogenous global regulators, such as those from extremophiles. This new approach can

  19. Chloroplast Redox Status Modulates Genome-Wide Plant Responses during the Non-host Interaction of Tobacco with the Hemibiotrophic Bacterium Xanthomonas campestris pv. vesicatoria

    Directory of Open Access Journals (Sweden)

    Juan J. Pierella Karlusich

    2017-07-01

    Full Text Available Non-host resistance is the most ample and durable form of plant resistance against pathogen infection. It includes induction of defense-associated genes, massive metabolic reprogramming, and in many instances, a form of localized cell death (LCD at the site of infection, purportedly designed to limit the spread of biotrophic and hemibiotrophic microorganisms. Reactive oxygen species (ROS have been proposed to act as signals for LCD orchestration. They are produced in various cellular compartments including chloroplasts, mitochondria and apoplast. We have previously reported that down-regulation of ROS build-up in chloroplasts by expression of a plastid-targeted flavodoxin (Fld suppressed LCD in tobacco leaves inoculated with the non-host bacterium Xanthomonas campestris pv. vesicatoria (Xcv, while other defensive responses were unaffected, suggesting that chloroplast ROS and/or redox status play a major role in the progress of LCD. To better understand these effects, we compare here the transcriptomic alterations caused by Xcv inoculation on leaves of Fld-expressing tobacco plants and their wild-type siblings. About 29% of leaf-expressed genes were affected by Xcv and/or Fld. Surprisingly, 5.8% of them (1,111 genes were regulated by Fld in the absence of infection, presumably representing pathways responsive to chloroplast ROS production and/or redox status during normal growth conditions. While the majority (∼75% of pathogen-responsive genes were not affected by Fld, many Xcv responses were exacerbated, attenuated, or regulated in opposite direction by expression of this protein. Particularly interesting was a group of 384 genes displaying Xcv responses that were already triggered by Fld in the absence of infection, suggesting that the transgenic plants had a larger and more diversified suite of constitutive defenses against the attacking microorganism compared to the wild type. Fld modulated many genes involved in pathogenesis, signal

  20. Environmental regulation of a global pollution externality in a bilateral trade framework: The case of global warming, China and the US

    OpenAIRE

    Gwatipedza, Johnson; Barbier, Edward B.

    2013-01-01

    Bilateral trade and capital flows have increased substantially between the United States and China yielding economic gains to both countries. However, these beneficial bilateral relations also bring about global environmental consequences including greenhouse gas emissions. The authors develop a footloose capital model of international trade between the North (United States) and the South (China) in the presence of a global pollution externality. Each country's share of global pollution depen...

  1. Dual-site phosphorylation of the control of virulence regulator impacts group a streptococcal global gene expression and pathogenesis.

    Directory of Open Access Journals (Sweden)

    Nicola Horstmann

    2014-05-01

    Full Text Available Phosphorylation relays are a major mechanism by which bacteria alter transcription in response to environmental signals, but understanding of the functional consequences of bacterial response regulator phosphorylation is limited. We sought to characterize how phosphorylation of the control of virulence regulator (CovR protein from the major human pathogen group A Streptococcus (GAS influences GAS global gene expression and pathogenesis. CovR mainly serves to repress GAS virulence factor-encoding genes and has been shown to homodimerize following phosphorylation on aspartate-53 (D53 in vitro. We discovered that CovR is phosphorylated in vivo and that such phosphorylation is partially heat-stable, suggesting additional phosphorylation at non-aspartate residues. Using mass spectroscopy along with targeted mutagenesis, we identified threonine-65 (T65 as an additional CovR phosphorylation site under control of the serine/threonine kinase (Stk. Phosphorylation on T65, as mimicked by the recombinant CovR T65E variant, abolished in vitro CovR D53 phosphorylation. Similarly, isoallelic GAS strains that were either unable to be phosphorylated at D53 (CovR-D53A or had functional constitutive phosphorylation at T65 (CovR-T65E had essentially an identical gene repression profile to each other and to a CovR-inactivated strain. However, the CovR-D53A and CovR-T65E isoallelic strains retained the ability to positively influence gene expression that was abolished in the CovR-inactivated strain. Consistent with these observations, the CovR-D53A and CovR-T65E strains were hypervirulent compared to the CovR-inactivated strain in a mouse model of invasive GAS disease. Surprisingly, an isoalleic strain unable to be phosphorylated at CovR T65 (CovR-T65A was hypervirulent compared to the wild-type strain, as auto-regulation of covR gene expression resulted in lower covR gene transcript and CovR protein levels in the CovR-T65A strain. Taken together, these data

  2. Colonización radical por endófitos fúngicos en Trithrinax campestris (Arecaceae de ecosistemas semiáridos del centro de Argentina Root colonization by fungal endophytes in Trithrinax campestris (Arecaceae from semiarid ecosystems from Central Argentine

    Directory of Open Access Journals (Sweden)

    Mónica A Lugo

    2011-12-01

    Full Text Available En ecosistemas áridos y semiáridos las raíces de las plantas suelen formar simbiosis con hongos, los que les proporcionan nutrientes y agua. Poco se conoce sobre los hongos asociados a palmeras nativas y cómo éstos podrían estar relacionados entre ellos. Se describe y cuantifica la colonización radical de los simbiontes de Trithrinax campestris en poblaciones leve y fuertemente afectadas por el fuego. T. campestris fue colonizada por hongos micorrícico-arbusculares (HMA y endófitos septados oscuros (ESO. La colonización por HMA fue del tipo intermedio entre los tipos Arum y Paris. La colonización por HMA y ESO y la producción de pelos radicales, presentó diferencias entre las poblaciones estudiadas. Los resultados sugieren que en T. campestris la relación entre hongos simbiontes/producción de pelos radicales podrían estar relacionada con su alta tolerancia al fuego y la aridez.In arid and semiarid ecosystems, roots frequently form symbiosis with fungi that provides access to nutrients and water. Knowledge regarding the study of fungal symbionts colonizing native palms roots is still scarce. We described, quantified and compared fungal colonization in roots of Trithrinax campestris from two environmental situations: population with weak-burning-signs and population with strong-burning-signs. T. campestris was colonized by arbuscular-mycorrhizal-fungi (AMF and dark-septate-endophytes (DSE. AMF colonization was an intermediate type between Arum and Paris. The AMF and DSE colonization and root hair production differed between populations. Our results suggest that in T. campestris the relation between fungal-symbionts and root-hair-production might be related to tolerance to burning and aridity.

  3. OxyR of Haemophilus parasuis is a global transcriptional regulator important in oxidative stress resistance and growth.

    Science.gov (United States)

    Wen, Yongping; Wen, Yiping; Wen, Xintian; Cao, Sanjie; Huang, Xiaobo; Wu, Rui; Zhao, Qin; Liu, Mafeng; Huang, Yong; Yan, Qigui; Han, Xinfeng; Ma, Xiaoping; Dai, Ke; Ding, Lingqiang; Liu, Sitong; Yang, Jian

    2018-02-15

    Haemophilus parasuis is an opportunistic pathogen and the causative agent of Glässer's disease in swine. This disease has high morbidity and mortality rates in swine populations, and is responsible for major economic losses worldwide. Survival of H. parasuis within the host requires mechanisms for coping with oxidative stress conditions. In many bacteria, OxyR is known to mediate protection against oxidative stress; however, little is known about the role of OxyR in H. parasuis. In the current study, an oxyR mutant strain was constructed in H. parasuis strain SC1401 and designated H. parasuis SC1401∆oxyR. The oxyR mutant strain had a slower growth rate and impaired biofilm formation compared to the wild type strain. Complementation restored the growth-associated phenotypes to wild type levels. Oxidative stress susceptibility testing, using a range of concentrations of H 2 O 2 , indicated that H. parasuis SC1401∆oxyR was more sensitive to oxidative stress than the wild type strain. RNA sequencing transcriptome analysis comparing H. parasuis SC1401 with H. parasuis SC1401∆oxyR identified 466 differentially expressed genes. These genes were involved in a wide range of biological processes, including: oxidative stress, transcriptional regulation, and DNA replication, recombination, and repair. These findings provide a foundation for future research to examine the role of OxyR as a global transcriptional regulator and to better define its role in oxidative stress resistance in H. parasuis. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. An Investigation of Adolescent Girls' Global Self-Concept, Physical Self-Concept, Identified Regulation, and Leisure-Time Physical Activity in Physical Education

    Science.gov (United States)

    Beasley, Emily Kristin; Garn, Alex C.

    2013-01-01

    This study examined the relationships among identified regulation, physical self-concept, global self-concept, and leisure-time physical activity with a sample of middle and high school girls (N = 319) enrolled in physical education. Based on Marsh's theory of self-concept, it was hypothesized that a) physical self-concept would mediate the…

  5. The Staphylococcus aureus Global Regulator MgrA Modulates Clumping and Virulence by Controlling Surface Protein Expression.

    Directory of Open Access Journals (Sweden)

    Heidi A Crosby

    2016-05-01

    Full Text Available Staphylococcus aureus is a human commensal and opportunistic pathogen that causes devastating infections in a wide range of locations within the body. One of the defining characteristics of S. aureus is its ability to form clumps in the presence of soluble fibrinogen, which likely has a protective benefit and facilitates adhesion to host tissue. We have previously shown that the ArlRS two-component regulatory system controls clumping, in part by repressing production of the large surface protein Ebh. In this work we show that ArlRS does not directly regulate Ebh, but instead ArlRS activates expression of the global regulator MgrA. Strains lacking mgrA fail to clump in the presence of fibrinogen, and clumping can be restored to an arlRS mutant by overexpressing either arlRS or mgrA, indicating that ArlRS and MgrA constitute a regulatory pathway. We used RNA-seq to show that MgrA represses ebh, as well as seven cell wall-associated proteins (SraP, Spa, FnbB, SasG, SasC, FmtB, and SdrD. EMSA analysis showed that MgrA directly represses expression of ebh and sraP. Clumping can be restored to an mgrA mutant by deleting the genes for Ebh, SraP and SasG, suggesting that increased expression of these proteins blocks clumping by steric hindrance. We show that mgrA mutants are less virulent in a rabbit model of endocarditis, and virulence can be partially restored by deleting the genes for the surface proteins ebh, sraP, and sasG. While mgrA mutants are unable to clump, they are known to have enhanced biofilm capacity. We demonstrate that this increase in biofilm formation is partially due to up-regulation of SasG, a surface protein known to promote intercellular interactions. These results confirm that ArlRS and MgrA constitute a regulatory cascade, and that they control expression of a number of genes important for virulence, including those for eight large surface proteins.

  6. Produção de goma xantana por cepas nativas de Xanthomonas campestris a partir de casca de cacau ou soro de leite Production of xanthan gum by Xanthomonas campestris strains native from bark cocoa or whey

    Directory of Open Access Journals (Sweden)

    Denis de M. Diniz

    2012-01-01

    Full Text Available Foi estudada a otimização do processo de produção de goma xantana a partir de casca de cacau ou soro de leite como fonte de carbono, e determinou-se o rendimento da goma obtida pela bioconversão de casca de cacau e soro de leite com a Xanthomonas campestris 1182. A goma foi produzida em meios com potássio e nitrogênio a 25 °C, 250 rpm por 120 horas. Os rendimentos foram: 2,335 g.L-1 para a sacarose; 4,995 g.L-1 para a casca de cacau seca e 12,01 g.L-1 utilizando soro de leite. Portanto, é viável a produção de goma xantana utilizando fontes de carbono como a casca de cacau e o soro de leite.The optimization of the production process of xanthan gum from cocoa husks or milk whey as carbon source was studied, and the production rate of gum obtained by the bioconversion of cocoa pods and whey was determined, using Xanthomonas campestris 1182. The gum was produced in a medium with potassium and nitrogen at 25 °C, 250 rpm for 120 hours. The results were: 2.335 g.L-1 for sucrose; 4.995 g.L-1 for cocoa dry pods and 12.01 g.L-1 using whey. Therefore, the production of xanthan gum is feasible upon using carbon sources such as cocoa hulls and whey.

  7. Kinetic analysis of growth and xanthan gum production with Xanthomonas campestris on sucrose, using sequentially consumed nitrogen sources.

    Science.gov (United States)

    Letisse, F; Chevallereau, P; Simon, J L; Lindley, N D

    2001-05-01

    A batch fermentation strategy using Xanthomonas campestris ATCC 13951 for xanthan gum production has been established in which all essential medium components are supplied at the onset. This has been achieved using sucrose as sole sugar feedstock. Sequential consumption of nitrogen sources (soybean hydrolysates, ammonium and nitrate salts) was observed to facilitate the further optimisation of the medium. Biomass accumulation was limited by phosphate availability. Xanthan yields of more than 60% (grams of xanthan per gram of sugar) have been obtained with constant acetyl content. However, pyruvyl substitution decreased as the growth rate declined, due to the metabolic constraints specific to phosphate depletion. High rates of carbon conversion into xanthan were observed throughout the culture and the ATP/ADP ratio was not affected by the decline in the specific growth rate.

  8. Elevation of secondary metabolites synthesis in Brassica campestris ssp. chinensis L. via exogenous inoculation of Piriformospora indica with appropriate fertilizer.

    Science.gov (United States)

    Khalid, Muhammad; Hassani, Danial; Bilal, Muhammad; Liao, Jianli; Huang, Danfeng

    2017-01-01

    This work evaluated the impact of exogenous soil inoculation of beneficial fungal strain Piriformospora indica on phytochemical changes and the related genes expression of Chinese cabbage (Brassica campestris ssp. chinensis L.) by greenhouse pot experiments. High performance liquid chromatography (HPLC) affirmed that among the different combinations of fungal and organic fertilizer treatments, the phenolic acids and flavonoids were considerably enriched in organic fertilizer and fungi (OP) followed by organic fertilizer, biochar, fungi (OBP) treated plants. The antiradical activity was higher in OP (61.29%) followed by P (60%) and organic fertilizer (OF) (53.84%) inoculated plants which positively correlated with chlorophyll, carotenoids and flavonoids level (Pindica significantly (Pindica. In conclusion, the results revealed that organic fertilizer and P. indica (OP) is the most appropriate combination for improving phytochemical and antiradical properties in Pakchoi.

  9. Producão de goma xantana por X. Campestris ATCC 13951 utilizando soro de queijo desproteinado

    Directory of Open Access Journals (Sweden)

    Jenny Sobenes G.

    2015-12-01

    Full Text Available A goma xantana é um biopolímero microbiano producido pela bactéria Xanthomonas. O presente trabalho teve como objetivo estudar a produção de goma xantana por processo fermentativo utilizando a linhagem X. campestris ATCC 13951 e como fonte de carbono: soro de queijo desproteinado suplementado com extrato de levedura e sulfato de amônia como fontes de nitrogênio; soro de queijo desproteinado suplementado só com extrato de levedura como fonte de nitrogênio e só soro de queijo desproteinado sem suplementos, tempo de fermentação de 72h para os três meios. Dos meios em análise aquele constituido apenas por soro de queijo desproteinado, atingiu o maior rendimento com valor de 58% e a melhor qualidade de goma.

  10. LesR is a novel upstream regulator that controls downstream Clp expression to modulate antibiotic HSAF biosynthesis and cell aggregation in Lysobacter enzymogenes OH11.

    Science.gov (United States)

    Xu, Huiyong; Wang, Ruping; Zhao, Yangyang; Fu, Zheng Qing; Qian, Guoliang; Liu, Fengquan

    2017-11-14

    Heat-stable antifungal factor (HSAF) is a polycyclic tetramate macrolactam secondary metabolite that exhibits broad-spectrum inhibitory activities against filamentous fungal pathogens. The native yield of this chemical is low. It is also a great challenge to synthesize HSAF artificially, due to its complex structure. Understanding the regulatory mechanism underlying HSAF biosynthesis could provide genetic basis for engineering high HSAF-producing strain. The transcription factor Clp is a global regulator that controls bacterial pathogenicity and the expression of one hundred related genes in the phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc). Diffusible signal factor (DSF) chemical signaling is the only well-characterized upstream regulatory pathway that involves downstream Clp regulation in Xcc. Such a regulatory hierarchy between DSF signaling and Clp is also conserved in the Gram-negative biological control agent Lysobacter enzymogenes, where the DSF signaling system controls antifungal antibiotic HSAF biosynthesis via Clp. Here, using LLysobacter enzymogenes OH11 as a working organism, we examined a novel upstream regulator, LesR, a LuxR solo that controls Clp expression to modulate HSAF biosynthesis as well as cell aggregation. We found that the overexpression of lesR in strain OH11 almost entirely shut down HSAF production and accelerated cell aggregation. These changed phenotypes could be rescued by the introduction of plasmid-borne clp in the lesR overexpression background. Consistent with findings, we further found that overexpression of lesR led to a decrease in the Clp level. These results collectively have shown that LesR could exert its function, i.e., HSAF biosynthesis, via downstream Clp. These findings were subsequently validated by a comparative transcriptome analysis, where the regulatory action of LesR was found to largely overlap with that of Clp. Therefore, in addition to the well-known DSF signaling system, the present

  11. Atrazine-resistant cytoplasmic male-sterile-nigra broccoli obtained by protoplast fusion between cytoplasmic male-sterile Brassica oleracea and atrazine-resistant Brassica campestris.

    Science.gov (United States)

    Christey, M C; Makaroff, C A; Earle, E D

    1991-12-01

    Protoplast fusion was used to combine the cytoplasmic traits of atrazine resistance and male sterility in Brassica oleracea var. italica (broccoli). Leaf protoplasts from broccoli with the petaloid B. nigra type of cytoplasmic male sterility were fused with hypocotyl protoplasts from an atrazine-resistant biotype of B. campestris var. oleifera cv Candle (oilseed rape). A total of 19 colonies regenerated shoots, all of which were broccolilike in phenotype, i.e., lacked trichomes. Four shoots, all from one colony, were atrazine resistant, surviving and growing in the presence of 25 μM atrazine. A leaf piece assay also confirmed that they were atrazine resistant. Molecular analysis showed that they contain chloroplasts from the atrazine-resistant B. campestris parent and mitochondria from the B. nigra parent. No recombination or rearrangement of the mitochondrial genomes in the fusion products was detected. These four plants and their progeny all showed the petaloid B. nigra type of male sterility.

  12. Multiplex PCR for specific and robust detection of Xanthomonas campestris pv. musacearum in pure culture and infected plant material

    DEFF Research Database (Denmark)

    Adriko, John; Aritua, V.; Mortensen, Carmen Nieves

    2012-01-01

    The present study developed a pathovar-specific PCR for the detection of Xanthomonas campestris pv. musacearum (Xcm), the cause of banana xanthomonas wilt, by amplification of a 265-bp region of the gene encoding the general secretion pathway protein D (GspD). A distinct DNA fragment of the expec......The present study developed a pathovar-specific PCR for the detection of Xanthomonas campestris pv. musacearum (Xcm), the cause of banana xanthomonas wilt, by amplification of a 265-bp region of the gene encoding the general secretion pathway protein D (GspD). A distinct DNA fragment...... was subsequently demonstrated in tests on artificially inoculated screenhouse cultivars of banana and field bananas with and without symptoms sampled from different parts of Uganda. This study therefore demonstrated a robust and specific Xcm diagnostic tool with the added advantage of applying internal PCR...

  13. Can the financialized atmosphere be effectively regulated? A critical analysis of the proposed Australian carbon pollution reduction scheme as a complex market solution to global warming

    Energy Technology Data Exchange (ETDEWEB)

    Windsor, C. [Bond Univ. (Australia); McNicholas, P. [Monash Univ. (Australia)

    2009-07-01

    A large body of scientific evidence indicates that global warming from human induced greenhouse gases (GHG) emissions is producing harmful climate change that will lead to global environmental and economic catastrophe within 10 years. The threat of human induced global warming has been on the international and public policy agenda for several years; for example on 11 December 1998, government representatives of 108 countries signed the United Nations Framework Convention on Climate Change (UNFCCC) an international agreement to reduce global warming or the Kyoto Protocol, with the then exception of the Australian and the United States (U.S.) governments. International action on GHG emissions reduction was thwarted by U.S. and Australian goverments. The then Australian government (1996-2007) surreptitiously funding by vested interests such as the coal industry, had no intention to act even though scientific evidence reported that Australia had begun to experience the detrimental effects of global warming. To fulfil an electoral promise, the center left Labor government signed the Kyoto Protocol on 3 December 2007. To deal with the global warming crisis, the Australian government has proposed an emissions trading scheme now officially called the 'Carbon Pollution Reduction Scheme' or CPRS. The proposed scheme is a cap and trade market mechanism that purportedly encourages businesses to operate more efficiently, thus reducing GHG emissions through price signalling in a government instigated market. Hence credible, transparent and efficient information underpins such a market in a post-Keynes deregulated world. The purpose of this paper is to critically examine the integrity of using current financial and reporting regulation that will oversee and monitor the veracity of newly commoditized carbon financial products, particularly since the global financial crisis has exposed significant financial regulatory weaknesses. Further we contend that current corporate

  14. Transgenic expression of the rice Xa21 pattern recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum

    OpenAIRE

    Tripathi, Jaindra Nath; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

    2014-01-01

    Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, bio-control agents or resistant cultivars available to control BXW. Here we take advantage of the robust resistance conferred by the rice pattern recognition receptor ...

  15. Onboard Hydrogen/Helium Sensors in Support of the Global Technical Regulation: An Assessment of Performance in Fuel Cell Electric Vehicle Crash Tests

    Energy Technology Data Exchange (ETDEWEB)

    Post, M. B.; Burgess, R.; Rivkin, C.; Buttner, W.; O' Malley, K.; Ruiz, A.

    2012-09-01

    Automobile manufacturers in North America, Europe, and Asia project a 2015 release of commercial hydrogen fuel cell powered light-duty road vehicles. These vehicles will be for general consumer applications, albeit initially in select markets but with much broader market penetration expected by 2025. To assure international harmony, North American, European, and Asian regulatory representatives are striving to base respective national regulations on an international safety standard, the Global Technical Regulation (GTR), Hydrogen Fueled Vehicle, which is part of an international agreement pertaining to wheeled vehicles and equipment for wheeled vehicles.

  16. Inducible Expression of the De-Novo Designed Antimicrobial Peptide SP1-1 in Tomato Confers Resistance to Xanthomonas campestris pv. vesicatoria.

    Directory of Open Access Journals (Sweden)

    Areli Herrera Diaz

    Full Text Available Antimicrobial peptides (AMPs are small peptides with less than 50 amino acids and are part of the innate immune response in almost all organisms, including bacteria, vertebrates, invertebrates and plants. AMPs are active against a broad-spectrum of pathogens. The inducible expression of AMPs in plants is a promising approach to combat plant pathogens with minimal negative side effects, such as phytotoxicity or infertility. In this study, inducible expression of the de-novo designed AMP SP1-1 in Micro Tom tomato protected tomato fruits against bacterial spot disease caused by Xanthomonas campestris pv. vesicatoria. The peptide SP1-1 was targeted to the apoplast which is the primary infection site for plant pathogens, by fusing SP1-1 peptide to the signal peptide RsAFP1 of radish (Raphanus sativus. The pathogen inducibility of the expression was enabled by using an optimized inducible 4XW2/4XS promoter. As a result, the tomato fruits of independently generated SP1-1 transgenic lines were significantly more resistant to X. campestris pv. vesicatoria than WT tomato fruits. In transgenic lines, bacterial infection was reduced up to 65% in comparison to the infection of WT plants. Our study demonstrates that the combination of the 4XW2/4XS cis-element from parsley with the synthetic antimicrobial peptide SP1-1 is a good alternative to protect tomato fruits against infections with X. campestris pv. vesicatoria.

  17. Characterization of BcMF23a and BcMF23b, two putative pectin methylesterase genes related to pollen development in Brassica campestris ssp. chinensis.

    Science.gov (United States)

    Lin, Sue; Huang, Li; Yu, Xiaolin; Xiong, Xingpeng; Yue, Xiaoyan; Liu, Tingting; Liang, Ying; Lv, Meiling; Cao, Jiashu

    2017-02-01

    Two homologous genes, Brassica campestris Male Fertility 23a (BcMF23a) and Brassica campestris Male Fertility 23b (BcMF23b), encoding putative pectin methylesterases (PMEs) were isolated from Brassica campestris ssp. chinensis (syn. Brassica rapa ssp. chinensis). These two genes sharing high sequence identity with each other were highly expressed in the fertile flower buds but silenced in the sterile ones of genic male sterile line system ('Bcajh97-01A/B'). Results of RT-PCR and in situ hybridization suggested that BcMF23a and BcMF23b were pollen-expressed genes, whose transcripts were first detected at the binucleate pollen and maintained throughout to the mature pollen grains. Western blot indicated that both of the putative BcMF23a and BcMF23b proteins are approximately 40 kDa, which exhibited extracellular localization revealed by transient expression analysis in the onion epidermal cells. The promoter of BcMF23a was active specifically in pollen during the late pollen developmental stages, while, in addition to the pollen, BcMF23b promoter drove an extra gene expression in the valve margins, abscission layer at the base of the first true leaves, taproot and lateral roots in seedlings.

  18. [The pTA29-barnase chimeric gene transformation of Brassica campestris L. subsp. chinensis Makino var. parachinensis mediated by agrobacterium].

    Science.gov (United States)

    Cao, Bihao; Meng, Chengmin; Lei, Jianjun; Chen, Guoju

    2008-05-01

    In order to induce male sterility of Brassica campestris L. subsp. chinensis Makino var. parachinensis, we introduced the chimeric pTA29-barnase gene into it by Agrobacteriumtume faciens transformation. We obtained the transgenic plants, and determined them by PCR, Southern blotting and RT-PCR analysis. Results indicated that the RNase (barnase) gene had been transferred into genome of plant, and its expression level was different among transformation plants. All transgenic plants were male sterile; there was no vigor or a little pollen without fertility in the anther of transgenic plants. The transgenic plants failed to produce seeds under the condition self-control pollination, but hybrid seeds set were obtained when these transgenic plants were cross-pollinated artificially with normal pollen from untransformed plants. Progeny from cross-pollinated maintainer line with transgenic plants segregated in the 1:1 for male sterility and male fertility, and these phenotypes corresponded directly to the presence or absence of the chimeri TA29-barnase gene. The male fertile plants of co-separated progenies could die by spraying 10 mg/L PPT in cotyledon seedling stage. The hybrid F1 between male sterility and other varieties showed heterosis in yield and growth. All these show that it is an efficient method to induce male sterility in Brassica campestris L. subsp. chinensis Makino var. parachinensis by TA29-barnase ene, there is potential on heterosis breeding of Brassica campestris L. subsp. chinensis Makino var. parachinensis.

  19. hrpf of Xanthomonas campestris pv. vesicatoria encodes an 87-kDa protein with homology to NoIX of Rhizobium fredii.

    Science.gov (United States)

    Huguet, E; Bonas, U

    1997-05-01

    The gram-negative bacterium Xanthomonas campestris pv. vesicatoria is the causal agent of bacterial spot disease on pepper and tomato plants. The main hrp (hypersensitive reaction and pathogenicity) gene cluster in X. campestris pv. vesicatoria spans a 23-kb chromosomal region, comprising six complementation groups designated hrpA to hrpF. Analysis of the hrpF locus revealed a single open reading frame encoding HrpF (86.4 kDa). HrpF is predominantly hydrophilic, and contains two hydrophobic domains in the C terminus. An interesting feature is the presence of two imperfect direct repeats in the N-terminal region. Deletion studies showed that one repeat is sufficient for function. Epitope tagging of HrpF allowed detection of the protein in X. campestris pv. vesicatoria. Subcellular localization studies suggest that HrpF is both in the soluble fraction and in the inner membrane. Interestingly, HrpF is 48% identical (67% similar) to the Rhizobium fredii NoIX protein that is part of the host specificity locus. Since several Hrp proteins are believed to be components of the types of III hrp protein secretion apparatus, allowing export of proteins essential for the interaction with the plant, the possible role of hrpF and NoIX in secretion is discussed.

  20. Significant rewiring of the transcriptome and proteome of an Escherichia coli strain harboring a tailored exogenous global regulator IrrE.

    Directory of Open Access Journals (Sweden)

    Tingjian Chen

    Full Text Available Cell reprogramming for microorganisms via engineered or artificial transcription factors and RNA polymerase mutants has presented a powerful tool for eliciting complex traits that are practically useful particularly for industrial strains, and for understanding at the global level the regulatory network of gene transcription. We previously further showed that an exogenous global regulator IrrE (derived from the extreme radiation-resistant bacterium Deinococcus radiodurans can be tailored to confer Escherichia coli (E. coli with significantly enhanced tolerances to different stresses. In this work, based on comparative transcriptomic and proteomic analyses of the representative strains E1 and E0, harboring the ethanol-tolerant IrrE mutant E1 and the ethanol-intolerant wild type IrrE, respectively, we found that the transcriptome and proteome of E. coli were extensively rewired by the tailored IrrE protein. Overall, 1196 genes (or approximately 27% of E. coli genes were significantly altered at the transcriptomic level, including notably genes in the nitrate-nitrite-nitric oxide (NO pathway, and genes for non-coding RNAs. The proteomic profile revealed significant up- or downregulation of several proteins associated with syntheses of the cell membrane and cell wall. Analyses of the intracellular NO level and cell growth under reduced temperature supported a close correlation between NO and ethanol tolerance, and also suggests a role for membrane fluidity. The significantly different omic profiles of strain E1 indicate that IrrE functions as a global regulator in E. coli, and that IrrE may be evolved for other cellular tolerances. In this sense, it will provide synthetic biology with a practical and evolvable regulatory "part" that operates at a higher level of complexity than local regulators. This work also suggests a possibility of introducing and engineering other exogenous global regulators to rewire the genomes of microorganism cells.

  1. DNA methylation-mediated down-regulation of DNA methyltransferase-1 (DNMT1) is coincident with, but not essential for, global hypomethylation in human placenta.

    Science.gov (United States)

    Novakovic, Boris; Wong, Nick C; Sibson, Mandy; Ng, Hong-Kiat; Morley, Ruth; Manuelpillai, Ursula; Down, Thomas; Rakyan, Vardhman K; Beck, Stephan; Hiendleder, Stefan; Roberts, Claire T; Craig, Jeffrey M; Saffery, Richard

    2010-03-26

    The genome of extraembryonic tissue, such as the placenta, is hypomethylated relative to that in somatic tissues. However, the origin and role of this hypomethylation remains unclear. The DNA methyltransferases DNMT1, -3A, and -3B are the primary mediators of the establishment and maintenance of DNA methylation in mammals. In this study, we investigated promoter methylation-mediated epigenetic down-regulation of DNMT genes as a potential regulator of global methylation levels in placental tissue. Although DNMT3A and -3B promoters lack methylation in all somatic and extraembryonic tissues tested, we found specific hypermethylation of the maintenance DNA methyltransferase (DNMT1) gene and found hypomethylation of the DNMT3L gene in full term and first trimester placental tissues. Bisulfite DNA sequencing revealed monoallelic methylation of DNMT1, with no evidence of imprinting (parent of origin effect). In vitro reporter experiments confirmed that DNMT1 promoter methylation attenuates transcriptional activity in trophoblast cells. However, global hypomethylation in the absence of DNMT1 down-regulation is apparent in non-primate placentas and in vitro derived human cytotrophoblast stem cells, suggesting that DNMT1 down-regulation is not an absolute requirement for genomic hypomethylation in all instances. These data represent the first demonstration of methylation-mediated regulation of the DNMT1 gene in any system and demonstrate that the unique epigenome of the human placenta includes down-regulation of DNMT1 with concomitant hypomethylation of the DNMT3L gene. This strongly implicates epigenetic regulation of the DNMT gene family in the establishment of the unique epigenetic profile of extraembryonic tissue in humans.

  2. Comment on ‘An index-based framework for assessing patterns and trends in river fragmentation and flow regulation by global dams at multiple scales’

    Science.gov (United States)

    Hennig, Thomas; Magee, Darrin

    2017-03-01

    In their article ‘An index-based framework for assessing patterns and trends in river fragmentation and flow regulation by global dams at multiple scales’ (2015 Environ. Res. Lett. 10 015001), Grill et al utilized a graph-based river routing model to simultaneously assess flow regulation and fragmentation by dams at multiple scales. Using global dam data they developed the river fragmentation index and the river regulation index, both based on river volume. Their results indicate that, on a global basis, 48% of river volume is moderately to severely impacted by either flow regulation, fragmentation, or both. Assuming completion of all dams planned and under construction in their future scenario, Grill et al find this number would rise to 93%, an effect they attribute largely to dam construction in the Amazon Basin. They also provide evidence for the importance of considering small- to medium-sized dams. We find this approach interesting and the analysis straightforward, but in this response note some limitations to the Asia-specific data on which the analysis is based. China and India are not only the two most populous countries, but are home to the vast majority of the world’s largest dams and reservoirs, numbers which will rapidly increase in the future. Grill et al however, limit their modeling and subsequent basin assessment (flow regulation and river fragmentation) to less than ten percent of existing and forthcoming dams in those two countries. While we suspect this is due to data limitations, it results in what we feel are significant misinterpretations of the future of dams and rivers across much of Asia.

  3. Effect of Scarification, Self-Inhibition, and Sowing Depth on Seed Germination of Lupinus campestris Efecto de la Escarificación, Autoinhibición y Profundidad de Siembra sobre la Germinación de Semillas de Lupinus campestris

    Directory of Open Access Journals (Sweden)

    Pedro Gutiérrez Nava

    2010-09-01

    Full Text Available Lupinus campestris Schltdl. & Cham. grows in shallow fields and disturbed areas of Central Mexico. It has potential to improve soil fertility and as fodder. Seeds of L. campestris show dormancy, and the technology needed to increase its potential use requires information about conditions favouring seed germination. The aim of this study was to evaluate the seed germination responseof L. campestris under controlled (laboratory and natural field conditions. Under laboratory conditions, 2 yr old seeds had a maximum germination percentage (50% when they were scarified with sulphuric acid for 90 min prior to sowing and when laboratory light (0.5 µmol m-2 s-1 was maintained during the diurnal period. Without scarification, only about 3% of the seeds germinated. Light in laboratory resulted in an increased seed germination as compared to darkness condition. In the field experiment 1 yr old seeds were used testing the following treatments: (a seed scarification (seeds scarified by 30 min immersion in sulphuric acid vs. not scarified, (b presence or absence of plants of L. campestris in plots before field experiments, and (c sowing depth (on soil surface and at 3 cm deep. The scarified seeds showed a germination percentage range between 50 and 64%, whereas non-scarified seeds had 9 to 16% germination. The seeds sowed in plots with or without plants of L. campestris (before the experiment germinated similarly, indicating no evidence of self-inhibition of germination. Three conclusions come out: (1 Scarification treatment with sulphuric acid effectively breaks dormancy in L. campestris seeds; (2 Direct sowing of scarified seeds (on the soil surface or at 3 cm depth resulted in a range of 50-64% of germination under field conditions; and (3 no evidence was obtained for self-inhibition or a positive interaction between preceding vegetation and seed germination of L. campestris.Lupinus campestris Schltdl. & Cham. crece en campos en descanso y

  4. Mergers during the first and second phase of globalization: Success, insider trading, and the role of regulation

    OpenAIRE

    Kling, Gerhard

    2004-01-01

    The merger wave that took place during the first phase of globalization, which lasted from 1895 to 1914, changed the industrial structure in Europe and the U.S. remarkably. Therefore, it is of great importance to assess whether mergers were successful during this period. Noteworthy, studies that evaluate the success of mergers during the first phase of globalization are still lacking for Germany. One may argue that this statement is false and could refer to Huerkamp (1979). However, he define...

  5. A Csr-type regulatory system, including small non-coding RNAs, regulates the global virulence regulator RovA of Yersinia pseudotuberculosis through RovM.

    Science.gov (United States)

    Heroven, Ann Kathrin; Böhme, Katja; Rohde, Manfred; Dersch, Petra

    2008-06-01

    The MarR-type regulator RovA controls expression of virulence genes of Yersinia pseudotuberculosis in response to environmental signals. Using a genetic strategy to discover components that influence rovA expression, we identified new regulatory factors with homology to components of the carbon storage regulator system (Csr). We showed that overexpression of a CsrB- or a CsrC-type RNA activates rovA, whereas a CsrA-like protein represses RovA synthesis. We further demonstrate that influence of the Csr system on rovA is indirect and occurs through control of the LysR regulator RovM, which inhibits rovA transcription. The CsrA protein had also a major influence on the motility of Yersinia, which was independent of RovM. The CsrB and CsrC RNAs are differentially expressed in Yersinia. CsrC is highly induced in complex but not in minimal media, indicating that medium-dependent rovM expression is mediated through CsrC. CsrB synthesis is generally very low. However, overexpression of the response regulator UvrY was found to activate CsrB production, which in turn represses CsrC synthesis independent of the growth medium. In summary, the post-transcriptional Csr-type components were shown to be key regulators in the co-ordinated environmental control of physiological processes and virulence factors, which are crucial for the initiation of Yersinia infections.

  6. The Dynamic Growth Exhibition and Accumulation of Cadmium of Pak Choi (Brassica campestris L. ssp. chinensis Grown in Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Hung-Yu Lai

    2013-10-01

    Full Text Available The accumulation of heavy metals, especially cadmium (Cd, in leafy vegetables was compared with other vegetables. Pak choi (Brassica campestris L. ssp. chinensis is a leafy vegetable consumed in Taiwan and its safety for consumption after growing in contaminated soils is a public concern. A pot experiment (50 days was conducted to understand the dynamic accumulation of Cd by pak choi grown in artificially contaminated soils. The edible parts of pak choi were sampled and analyzed every 2–3 days. The dry weight (DW of pak choi was an exponential function of leaf length, leaf width, and chlorophyll content. The accumulation of Cd increased when the soil Cd concentration was raised, but was kept at a constant level during different growth stages. Pak choi had a high bioconcentration factor (BCF = ratio of the concentration in the edible parts to that in the soils, at values of 3.5–4.0. The consumption of pak choi grown in soils contaminated at levels used in this study would result in the ingestion of impermissible amounts of Cd and could possibly have harmful effects on health.

  7. Biophysical characterization of the outer membrane polysaccharide export protein and the polysaccharide co-polymerase protein from Xanthomonas campestris.

    Science.gov (United States)

    Bianco, M I; Jacobs, M; Salinas, S R; Salvay, A G; Ielmini, M V; Ielpi, L

    2014-09-01

    This study investigated the structural and biophysical characteristics of GumB and GumC, two Xanthomonas campestris membrane proteins that are involved in xanthan biosynthesis. Xanthan is an exopolysaccharide that is thought to be a virulence factor that contributes to bacterial in planta growth. It also is one of the most important industrial biopolymers. The first steps of xanthan biosynthesis are well understood, but the polymerization and export mechanisms remain unclear. For this reason, the key proteins must be characterized to better understand these processes. Here we characterized, by biochemical and biophysical techniques, GumB, the outer membrane polysaccharide export protein, and GumC, the polysaccharide co-polymerase protein of the xanthan biosynthesis system. Our results suggested that recombinant GumB is a tetrameric protein in solution. On the other hand, we observed that both native and recombinant GumC present oligomeric conformation consistent with dimers and higher-order oligomers. The transmembrane segments of GumC are required for GumC expression and/or stability. These initial results provide a starting point for additional studies that will clarify the roles of GumB and GumC in the xanthan polymerization and export processes and further elucidate their functions and mechanisms of action. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Sulfate sorption on rape (Brassica campestris L.) straw biochar, loess soil and a biochar-soil mixture.

    Science.gov (United States)

    Zhao, Baowei; Nan, Xujun; Xu, Huan; Zhang, Tao; Ma, Fengfeng

    2017-10-01

    The effects of biochar amendment on sulfur behavior in soils are unknown. In this paper, sulfate (SO42-) sorption on rape (Brassica campestris L.) straw biochar produced at 600 °C (BC), loess soil (soil) and a 1:9 (w/w) biochar-soil mixture (BC-soil) was investigated by batch experiments. The effects of contact time, initial SO42- concentration, temperature and solution pH value on sorption were tested. Kinetics, isotherms and thermodynamics for sorption were investigated. Pre- and post-sorption characterizations of BC and soil were respectively studied using Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopy, respectively. It has been shown that SO42- sorption on three sorbents was well described by pseudo-second-order kinetic model. The sorption isotherms could be fitted using Langmuir and Freundlich models. BC amendment did not increase the sorption capacity of soil for SO42-. The values of ΔG0, ΔH0 and ΔS0 indicated that the nature of sorption was spontaneous, endothermic and feasible. Increasing solution pH value led to a slight reduction in the sorption amount of SO42-. Sulfate was mainly sorbed onto BC through electrostatic interaction, whereas onto the soil via electrostatic interaction and formation of poorly soluble CaSO4. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Genetic Damage Induced by a Food Coloring Dye (Sunset Yellow on Meristematic Cells of Brassica campestris L.

    Directory of Open Access Journals (Sweden)

    Kshama Dwivedi

    2015-01-01

    Full Text Available We have performed the present piece of work to evaluate the effect of synthetic food coloring azo dye (sunset yellow on actively dividing root tip cells of Brassica campestris L. Three doses of azo dye were administered for the treatment of actively dividing root tip cells, namely, 1%, 3%, and 5%, for 6-hour duration along with control. Mitotic analysis clearly revealed the azo dye induced endpoint deviation like reduction in the frequency of normal divisions in a dose dependent manner. Mitotic divisions in the control sets were found to be perfectly normal while dose based reduction in MI was registered in the treated sets. Azo dye has induced several chromosomal aberrations (genotoxic effect at various stages of cell cycle such as stickiness of chromosomes, micronuclei formation, precocious migration of chromosome, unorientation, forward movement of chromosome, laggards, and chromatin bridge. Among all, stickiness of chromosomes was present in the highest frequency followed by partial genome elimination as micronuclei. The present study suggests that extensive use of synthetic dye should be forbidden due to genotoxic and cytotoxic impacts on living cells. Thus, there is an urgent need to assess potential hazardous effects of these dyes on other test systems like human and nonhuman biota for better scrutiny.

  10. Genetic damage induced by a food coloring dye (sunset yellow) on meristematic cells of Brassica campestris L.

    Science.gov (United States)

    Dwivedi, Kshama; Kumar, Girjesh

    2015-01-01

    We have performed the present piece of work to evaluate the effect of synthetic food coloring azo dye (sunset yellow) on actively dividing root tip cells of Brassica campestris L. Three doses of azo dye were administered for the treatment of actively dividing root tip cells, namely, 1%, 3%, and 5%, for 6-hour duration along with control. Mitotic analysis clearly revealed the azo dye induced endpoint deviation like reduction in the frequency of normal divisions in a dose dependent manner. Mitotic divisions in the control sets were found to be perfectly normal while dose based reduction in MI was registered in the treated sets. Azo dye has induced several chromosomal aberrations (genotoxic effect) at various stages of cell cycle such as stickiness of chromosomes, micronuclei formation, precocious migration of chromosome, unorientation, forward movement of chromosome, laggards, and chromatin bridge. Among all, stickiness of chromosomes was present in the highest frequency followed by partial genome elimination as micronuclei. The present study suggests that extensive use of synthetic dye should be forbidden due to genotoxic and cytotoxic impacts on living cells. Thus, there is an urgent need to assess potential hazardous effects of these dyes on other test systems like human and nonhuman biota for better scrutiny.

  11. Efficacy of Copper Compounds in Controlling Xanthomonas campestris pv. vesicatoria, the Causal Agent of Bacterial Spot of Pepper

    Directory of Open Access Journals (Sweden)

    Svetlana Milijašević

    2006-01-01

    Full Text Available The efficacy of several new formulations of copper compounds in controlling Xanthomonas campestris pv. vesicatoria in pepper was estimated in field conditions using artificial inoculation. The efficacies of Cuprozin 35 WP (copper-oxychloride and Blauvit(copper-hydroxide were tested in the localities Dobanovci and Kupinovo in 2005. Another two formulations, Cuproxat (copper-sulfate and Fungohem SC (copper-hydroxide, were tested along with the previous two in the localities Zemun and Smederevska Palanka in2006. Both bactericides tested in 2005 exhibited high efficacy in controlling X. c. pv. vesicatoria in both localities. However, there were no significant differences in the efficacy of Cuprozin 35 WP at higher concentration (74.3%-78.7% and Blauvit (74.6%-78.9% inthe two trials. Cuprozin 35 WP decreased efficacy, but a satisfactory effectiveness was still achieved at lower concentration (66.5%-66.5%. In the experiments conducted in 2006, higher concentration of Fungohem SC showed the highest efficacy (86.1%-89.1% in controllingbacterial spot of pepper. Blauvit, Cuprozin 35 WP and Cuproxat also exhibited high efficacy. However, there were no significant differences in the efficacy of these bactericides between the two localities. Fungohem SC applied at lower concentration was less effective (77.2%-80.0% but its efficacy was still good enough. Our experiments showed that copper bactericides based on copper-sulfate, copper-oxychloride and copper-hydroxide exhibited satisfactory efficacy in controlling the causal agent of bacterial spot of pepper in our climatic conditions.

  12. Fis is a global regulator critical for modulation of virulence factor production and pathogenicity of Dickeya zeae

    OpenAIRE

    Lv, Mingfa; Chen, Yufan; Liao, Lisheng; Liang, Zhibin; Shi, Zurong; Tang, Yingxin; Ye, Sixuan; Zhou, Jianuan; Zhang, Lianhui

    2018-01-01

    Dickeya zeae is the causal agent of rice foot rot disease, which has recently become a great threat to rice planting countries and regions. The pathogen produces a family of phytotoxins named zeamines that is critical for bacterial virulence, but little is known about the signaling pathways and regulatory mechanisms that govern zeamine production. In this study, we showed that a conserved transcriptional regulator Fis is involved in the regulation of zeamine production in D. zeae strain EC1. ...

  13. Proteomic Analysis of a Global Regulator GacS Sensor Kinase in the Rhizobacterium, Pseudomonas chlororaphis O6

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    Chul Hong Kim

    2014-06-01

    Full Text Available The GacS/GacA system in the root colonizer Pseudomonas chlororaphis O6 is a key regulator of many traits relevant to the biocontrol function of this bacterium. Proteomic analysis revealed 12 proteins were down-regulated in a gacS mutant of P. chlororaphis O6. These GacS-regulated proteins functioned in combating oxidative stress, cell signaling, biosynthesis of secondary metabolism, and secretion. The extent of regulation was shown by real-time RT-PCR to vary between the genes. Mutants of P. chlororaphis O6 were generated in two GacS-regulated genes, trpE, encoding a protein involved in tryptophan synthesis, and prnA, required for conversion of tryptophan to the antimicrobial compound, pyrrolitrin. Failure of the trpE mutant to induce systemic resistance in tobacco against a foliar pathogen causing soft rot, Pectobacterium carotovorum SCCI, correlated with reduced colonization of root surfaces implying an inadequate supply of tryptophan to support growth. Although colonization was not affected by mutation in the prnA gene, induction of systemic resistance was reduced, suggesting that pyrrolnitrin was an activator of plant resistance as well as an antifungal agent. Study of mutants in the other GacS-regulated proteins will indicate further the features required for biocontrol-activity in this rhizobacterium.

  14. Limited functional conservation of a global regulator among related bacterial genera: Lrp in Escherichia, Proteus and Vibrio

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    Martinez-Vaz Betsy M

    2008-04-01

    Full Text Available Abstract Background Bacterial genome sequences are being determined rapidly, but few species are physiologically well characterized. Predicting regulation from genome sequences usually involves extrapolation from better-studied bacteria, using the hypothesis that a conserved regulator, conserved target gene, and predicted regulator-binding site in the target promoter imply conserved regulation between the two species. However many compared organisms are ecologically and physiologically diverse, and the limits of extrapolation have not been well tested. In E. coli K-12 the leucine-responsive regulatory protein (Lrp affects expression of ~400 genes. Proteus mirabilis and Vibrio cholerae have highly-conserved lrp orthologs (98% and 92% identity to E. coli lrp. The functional equivalence of Lrp from these related species was assessed. Results Heterologous Lrp regulated gltB, livK and lrp transcriptional fusions in an E. coli background in the same general way as the native Lrp, though with significant differences in extent. Microarray analysis of these strains revealed that the heterologous Lrp proteins significantly influence only about half of the genes affected by native Lrp. In P. mirabilis, heterologous Lrp restored swarming, though with some pattern differences. P. mirabilis produced substantially more Lrp than E. coli or V. cholerae under some conditions. Lrp regulation of target gene orthologs differed among the three native hosts. Strikingly, while Lrp negatively regulates its own gene in E. coli, and was shown to do so even more strongly in P. mirabilis, Lrp appears to activate its own gene in V. cholerae. Conclusion The overall similarity of regulatory effects of the Lrp orthologs supports the use of extrapolation between related strains for general purposes. However this study also revealed intrinsic differences even between orthologous regulators sharing >90% overall identity, and 100% identity for the DNA-binding helix-turn-helix motif

  15. The Future of Governance in the Global Bioeconomy: Policy, Regulation, and Investment Challenges for the Biotechnology and Bioenergy Sectors

    NARCIS (Netherlands)

    Wesseler, J.H.H.; Spielmann, M.; Demont, M.

    2010-01-01

    Today more than ever, the global bioeconomy is the subject of focused attention from public policymakers, corporate decision makers, researchers in the social and biophysical sciences, and the general public. With both short- and long-term shifts in the world’s demand and supply of agricultural and

  16. Developing Global Leaders for Research, Regulation, and Stewardship of Crop Protection Chemistry in the 21st Century

    Science.gov (United States)

    To provide sufficient food and fiber to the increasing global population, the technologies associated with crop protection are growing ever more sophisticated but, at the same time, societal expectations for the safe use of crop protection chemistry tools are also increasing. The...

  17. IrrE, a global regulator of extreme radiation resistance in Deinococcus radiodurans, enhances salt tolerance in Escherichia coli and Brassica napus.

    Directory of Open Access Journals (Sweden)

    Jie Pan

    Full Text Available BACKGROUND: Globally, about 20% of cultivated land is now affected by salinity. Salt tolerance is a trait of importance to all crops in saline soils. Previous efforts to improve salt tolerance in crop plants have met with only limited success. Bacteria of the genus Deinococcus are known for their ability to survive highly stressful conditions, and therefore possess a unique pool of genes conferring extreme resistance. In Deinococcus radiodurans, the irrE gene encodes a global regulator responsible for extreme radioresistance. METHODOLOGY/PRINCIPAL FINDINGS: Using plate assays, we showed that IrrE protected E. coli cells against salt shock and other abiotic stresses such as oxidative, osmotic and thermal shocks. Comparative proteomic analysis revealed that IrrE functions as a switch to regulate different sets of proteins such as stress responsive proteins, protein kinases, glycerol-degrading enzymes, detoxification proteins, and growth-related proteins in E. coli. We also used quantitative RT-PCR to investigate expression of nine selected stress-responsive genes in transgenic and wild-type Brassica napus plants. Transgenic B. napus plants expressing the IrrE protein can tolerate 350 mM NaCl, a concentration that inhibits the growth of almost all crop plants. CONCLUSIONS: Expression of IrrE, a global regulator for extreme radiation resistance in D. radiodurans, confers significantly enhanced salt tolerance in both E. coli and B. napus. We thus propose that the irrE gene might be used as a potentially promising transgene to improve abiotic stress tolerances in crop plants.

  18. Reação de genótipos de feijoeiro comum a Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina e Xanthomonas campestris pv. phaseoli Behavior of dry bean genotypes to Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina, and Xanthomonas campestris pv. phaseoli

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Maringoni

    1999-04-01

    Full Text Available Foi avaliado no presente trabalho o comportamento dos genótipos de feijoeiro (Phaseolus vulgaris L. PI 150414, PI 163117, PI 175829 branco, PI 175829 roxo, PI 175858, PI 197687, A 417, A 420, A 429, Xan 160, Xan 161, WISHBR 40 e IAC Carioca inoculados com Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina e Xanthomonas campestris pv. phaseoli, sob condições de telado/casa de vegetação. Verificou-se que os genótipos Xan 160, PI 150414, A 417, PI 175829 roxo, Xan 161, A 420, PI 163117 e PI 175829 branco foram resistentes a F. oxysporum f. sp. phaseoli e somente o PI 175829 branco apresentou bom nível de resistência a M. phaseolina. Com relação ao comportamento desses genótipos a X. campestris pv. phaseoli, eles foram altamente suscetíveis ao isolado Feij-4 e apenas o genótipo Xan 161 apresentou nível moderado de resistência foliar ao isolado Feij-41.The behavior of dry bean (Phaseolus vulgaris L. genotypes PI 150414, PI 163117, PI 175829 white, PI 175829 purple, PI 175858, PI 197687, A 417, A 420, A 429, Xan 160, Xan 161, WISHBR 40, and IAC Carioca inoculated with Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina, and Xanthomonas campestris pv. phaseoli was evaluated under greenhouse condition. The bean genotypes Xan 160, PI 150414, A 417, PI 175829 purple, Xan 161, A 420, PI 163117, and PI 175829 white were resistant to F. oxysporum f. sp. phaseoli, and only PI 155829 white had a good level of resistance to M. phaseolina. All bean genotypes were susceptible to Feij-4 strain, and only Xan 161 had some level of leaf resistance to Feij-41 strain of X. campestris pv. phaseoli.

  19. Expression of the gapA gene encoding glyceraldehyde-3-phosphate dehydrogenase of Corynebacterium glutamicum is regulated by the global regulator SugR.

    Science.gov (United States)

    Toyoda, Koichi; Teramoto, Haruhiko; Inui, Masayuki; Yukawa, Hideaki

    2008-11-01

    Regulation of expression of the gapA gene encoding glyceraldehyde-3-phosphate dehydrogenase essential for glycolysis in Corynebacterium glutamicum was studied. We applied DNA affinity beads to isolate proteins binding to the promoter region of the gapA gene and obtained SugR, which has been shown to be a repressor of pts genes involved in sugar transport system. The results of electrophoretic mobility shift assays revealed that SugR specifically bound to the gapA promoter and the consensus sequence TGTTTG in the promoter region was required for its binding. We examined expression of the gapA gene in a sugR deletion mutant. Effect of mutation in the SugR binding site on gapA-lacZ fusion expression was also examined. These assays revealed that SugR acts as a negative transcriptional regulator of the gapA gene in the absence of sugar, and repression by SugR is alleviated in the presence of sugar, i.e., fructose and sucrose. Fructose-1-phosphate and fructose-1,6-bisphosphate revealed negative effects on binding of SugR to the gapA promoter, indicating that the sugar metabolites are involved in the derepression of gapA expression.

  20. Crystal Structures of the Reduced, Sulfenic Acid, and Mixed Disulfide Forms of SarZ, a Redox Active Global Regulator in Staphylococcus aureus

    Energy Technology Data Exchange (ETDEWEB)

    Poor, Catherine B.; Chen, Peng R.; Duguid, Erica; Rice, Phoebe A.; He, Chuan; (UC)

    2010-01-20

    SarZ is a global transcriptional regulator that uses a single cysteine residue, Cys{sup 13}, to sense peroxide stress and control metabolic switching and virulence in Staphylococcus aureus. SarZ belongs to the single-cysteine class of OhrR-MgrA proteins that play key roles in oxidative resistance and virulence regulation in various bacteria. We present the crystal structures of the reduced form, sulfenic acid form, and mixed disulfide form of SarZ. Both the sulfenic acid and mixed disulfide forms are structurally characterized for the first time for this class of proteins. The Cys{sup 13} sulfenic acid modification is stabilized through two hydrogen bonds with surrounding residues, and the overall DNA-binding conformation is retained. A further reaction of the Cys{sup 13} sulfenic acid with an external thiol leads to formation of a mixed disulfide bond, which results in an allosteric change in the DNA-binding domains, disrupting DNA binding. Thus, the crystal structures of SarZ in three different states provide molecular level pictures delineating the mechanism by which this class of redox active regulators undergoes activation. These structures help to understand redox-mediated virulence regulation in S. aureus and activation of the MarR family proteins in general.

  1. In silico clustering of Salmonella global gene expression data reveals novel genes co-regulated with the SPI-1 virulence genes through HilD.

    Science.gov (United States)

    Martínez-Flores, Irma; Pérez-Morales, Deyanira; Sánchez-Pérez, Mishael; Paredes, Claudia C; Collado-Vides, Julio; Salgado, Heladia; Bustamante, Víctor H

    2016-11-25

    A wide variety of Salmonella enterica serovars cause intestinal and systemic infections to humans and animals. Salmonella Patogenicity Island 1 (SPI-1) is a chromosomal region containing 39 genes that have crucial virulence roles. The AraC-like transcriptional regulator HilD, encoded in SPI-1, positively controls the expression of the SPI-1 genes, as well as of several other virulence genes located outside SPI-1. In this study, we applied a clustering method to the global gene expression data of S. enterica serovar Typhimurium from the COLOMBOS database; thus genes that show an expression pattern similar to that of SPI-1 genes were selected. This analysis revealed nine novel genes that are co-expressed with SPI-1, which are located in different chromosomal regions. Expression analyses and protein-DNA interaction assays showed regulation by HilD for six of these genes: gtgE, phoH, sinR, SL1263 (lpxR) and SL4247 were regulated directly, whereas SL1896 was regulated indirectly. Interestingly, phoH is an ancestral gene conserved in most of bacteria, whereas the other genes show characteristics of genes acquired by Salmonella. A role in virulence has been previously demonstrated for gtgE, lpxR and sinR. Our results further expand the regulon of HilD and thus identify novel possible Salmonella virulence genes.

  2. Fnr, a global transcriptional regulator of Escherichia coli, activates the Vitreoscilla hemoglobin (VHb) promoter and intracellular VHb expression increases cytochrome d promoter activity.

    Science.gov (United States)

    Tsai, P S; Kallio, P T; Bailey, J E

    1995-01-01

    The oxygen-regulated promoter (Pvhb) of the Vitreoscilla hemoglobin gene has been applied to direct high-level expression of several cloned proteins, including Vitreoscilla hemoglobin (VHb), which improves productivity of many aerobic processes. In an effort to gain a better understanding of the regulation of Pvhb, and to guide further optimization of this technology, we investigated whether the Escherichia coli global regulatory molecules Fnr and the Arc system (ArcA and ArcB), which control the expression of various genes under either aerobic or anaerobic conditions, also regulate Pvhb activity in E. coli. The activity of Pvhb and the expression of VHb in E. coli were activated by Fnr, but were relatively unaffected by the Arc system under microaerobic conditions (DO less than 2% air saturation). We also examined the possibility of VHb affecting cytochrome d promoter activity during microaerobiosis. The presence of VHb increased the activity of beta-galactosidase from a cytochrome d promoter-lacZ fusion by 1.5-fold. This indicates that VHb affects oxygen-regulated transcription of E. coli genes and may contribute to the modified physiology observed in VHb-expressing E. coli.

  3. The Crc global regulator binds to an unpaired A-rich motif at the Pseudomonas putida alkS mRNA coding sequence and inhibits translation initiation.

    Science.gov (United States)

    Moreno, Renata; Marzi, Stefano; Romby, Pascale; Rojo, Fernando

    2009-12-01

    Crc is a key global translational regulator in Pseudomonads that orchestrates the hierarchy of induction of several catabolic pathways for amino acids, sugars, hydrocarbons or aromatic compounds. In the presence of amino acids, which are preferred carbon sources, Crc inhibits translation of the Pseudomonas putida alkS and benR mRNAs, which code for transcriptional regulators of genes required to assimilate alkanes (hydrocarbons) and benzoate (an aromatic compound), respectively. Crc binds to the 5'-end of these mRNAs, but the sequence and/or structure recognized, and the way in which it inhibits translation, were unknown. We have determined the secondary structure of the alkS mRNA 5'-end through its sensitivity to several ribonucleases and chemical reagents. Footprinting and band-shift assays using variant alkS mRNAs have shown that Crc specifically binds to a short unpaired A-rich sequence located adjacent to the alkS AUG start codon. This interaction is stable enough to prevent formation of the translational initiation complex. A similar Crc-binding site was localized at benR mRNA, upstream of the Shine-Dalgarno sequence. This allowed predicting binding sites at other Crc-regulated genes, deriving a consensus sequence that will help to validate new Crc targets and to discriminate between direct and indirect effects of this regulator.

  4. The Future of Governance in the Global Bioeconomy: Policy, Regulation, and Investment Challenges for the Biotechnology and Bioenergy Sectors

    OpenAIRE

    Wesseler, J.H.H.; Spielmann, M.; Demont, M.

    2010-01-01

    Today more than ever, the global bioeconomy is the subject of focused attention from public policymakers, corporate decision makers, researchers in the social and biophysical sciences, and the general public. With both short- and long-term shifts in the world’s demand and supply of agricultural and industrial production, there is growing concern over the economics of improving productive efficiency through science conducted at the genetic and molecular levels. Parallel to this, there is growi...

  5. Metabolic regulation is sufficient for global and robust coordination of glucose uptake, catabolism, energy production and growth in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Pierre Millard

    2017-02-01

    Full Text Available The metabolism of microorganisms is regulated through two main mechanisms: changes of enzyme capacities as a consequence of gene expression modulation ("hierarchical control" and changes of enzyme activities through metabolite-enzyme interactions. An increasing body of evidence indicates that hierarchical control is insufficient to explain metabolic behaviors, but the system-wide impact of metabolic regulation remains largely uncharacterized. To clarify its role, we developed and validated a detailed kinetic model of Escherichia coli central metabolism that links growth to environment. Metabolic control analyses confirm that the control is widely distributed across the network and highlight strong interconnections between all the pathways. Exploration of the model solution space reveals that several robust properties emerge from metabolic regulation, from the molecular level (e.g. homeostasis of total metabolite pool to the overall cellular physiology (e.g. coordination of carbon uptake, catabolism, energy and redox production, and growth, while allowing a large degree of flexibility at most individual metabolic steps. These properties have important physiological implications for E. coli and significantly expand the self-regulating capacities of its metabolism.

  6. Development of a molecular method for detection and identification of Xanthomonas campestris pv. viticola Desenvolvimento de um método molecular para detecção e identificação de Xanthomonas campestris pv. viticola

    Directory of Open Access Journals (Sweden)

    Loiselene Carvalho da Trindade

    2007-03-01

    Full Text Available In order to develop a molecular method for detection and identification of Xanthomonas campestris pv. viticola (Xcv the causal agent of grapevine bacterial canker, primers were designed based on the partial sequence of the hrpB gene. Primer pairs Xcv1F/Xcv3R and RST2/Xcv3R, which amplified 243- and 340-bp fragments, respectively, were tested for specificity and sensitivity in detecting DNA from Xcv. Amplification was positive with DNA from 44 Xcv strains and with DNA from four strains of X. campestris pv. mangiferaeindicae and five strains of X. axonopodis pv. passiflorae, with both primer pairs. However, the enzymatic digestion of PCR products could differentiate Xcv strains from the others. None of the primer pairs amplified DNA from grapevine, from 20 strains of nonpathogenic bacteria from grape leaves and 10 strains from six representative genera of plant pathogenic bacteria. Sensitivity of primers Xcv1F/Xcv3R and RST2/Xcv3R was 10 pg and 1 pg of purified Xcv DNA, respectively. Detection limit of primers RST2/Xcv3R was 10(4 CFU/ml, but this limit could be lowered to 10² CFU/ml with a second round of amplification using the internal primer Xcv1F. Presence of Xcv in tissues of grapevine petioles previously inoculated with Xcv could not be detected by PCR using macerated extract added directly in the reaction. However, amplification was positive with the introduction of an agar plating step prior to PCR. Xcv could be detected in 1 µl of the plate wash and from a cell suspension obtained from a single colony. Bacterium identity was confirmed by RFLP analysis of the RST2/Xcv3R amplification products digested with Hae III.Com o objetivo de desenvolver um método molecular para detecção e identificação de Xanthomonas campestris pv. viticola (Xcv, agente causal do cancro bacteriano da videira, oligonucleotídeos (primers foram desenhados com base na seqüência parcial do gene hrpB. As combinações de primers Xcv1F/Xcv3R e RST2/Xcv3R que

  7. Global Regulator of Virulence A (GrvA) Coordinates Expression of Discrete Pathogenic Mechanisms in Enterohemorrhagic Escherichia coli through Interactions with GadW-GadE.

    Science.gov (United States)

    Morgan, Jason K; Carroll, Ronan K; Harro, Carly M; Vendura, Khoury W; Shaw, Lindsey N; Riordan, James T

    2015-11-02

    Global regulator of virulence A (GrvA) is a ToxR-family transcriptional regulator that activates locus of enterocyte effacement (LEE)-dependent adherence in enterohemorrhagic Escherichia coli (EHEC). LEE activation by GrvA requires the Rcs phosphorelay response regulator RcsB and is sensitive to physiologically relevant concentrations of bicarbonate, a known stimulant of virulence systems in intestinal pathogens. This study determines the genomic scale of GrvA-dependent regulation and uncovers details of the molecular mechanism underlying GrvA-dependent regulation of pathogenic mechanisms in EHEC. In a grvA-null background of EHEC strain TW14359, RNA sequencing analysis revealed the altered expression of over 700 genes, including the downregulation of LEE- and non-LEE-encoded effectors and the upregulation of genes for glutamate-dependent acid resistance (GDAR). Upregulation of GDAR genes corresponded with a marked increase in acid resistance. GrvA-dependent regulation of GDAR and the LEE required gadE, the central activator of GDAR genes and a direct repressor of the LEE. Control of gadE by GrvA was further determined to occur through downregulation of the gadE activator GadW. This interaction of GrvA with GadW-GadE represses the acid resistance phenotype, while it concomitantly activates the LEE-dependent adherence and secretion of immune subversion effectors. The results of this study significantly broaden the scope of GrvA-dependent regulation and its role in EHEC pathogenesis. Enterohemorrhagic Escherichia coli (EHEC) is an intestinal human pathogen causing acute hemorrhagic colitis and life-threatening hemolytic-uremic syndrome. For successful transmission and gut colonization, EHEC relies on the glutamate-dependent acid resistance (GDAR) system and a type III secretion apparatus, encoded on the LEE pathogenicity island. This study investigates the mechanism whereby the DNA-binding regulator GrvA coordinates activation of the LEE with repression of GDAR

  8. Role of nitrification inhibitor DMPP (3, 4-dimethylpyrazole phosphate) in NO(3-)-N accumulation in greengrocery( Brassica campestris L. ssp. chinensis) and vegetable soil.

    Science.gov (United States)

    Xu, Chao; Wu, Liang-huan; Ju, Xiao-tang; Zhang, Fu-suo

    2005-01-01

    The influence of nitrification inhibitor (NI) 3, 4-dimethylpyrazole phosphate (DMPP) on nitrate accumulation in greengrocery (Brassica campestris L. ssp. chinensis) and vegetable soil at surface layer were investigated in field experiments in 2002 and 2003. Results showed that NI DMPP took no significant effect on yields of edible parts of greengrocery, but it could significantly decrease NO(3-)-N concentration in greengrocery and in vegetable soil at surface layer. In addition, NI DMPP could reduce the NO(3-)-N concentration during the prophase stage of storage.

  9. Características y mecanismos funcionales involucrados en la ecofisiología de Flourensia campestris Y Flourensia oolepis (Asteraceae)

    OpenAIRE

    Silva, Mariana

    2012-01-01

    Flourensia campestris (FC)y F. oolepis (FO), son arbustos nativos que crecen en zonas áridas de Córdoba, formando comunidades ('chilcales')de alto valor ecológico en estos ecosistemas. Estos ambientes se hallan expuestos a diversos factores de estrés abiótico a los que las plantas se han adaptado. Esta tesis se centró en dilucidar adaptaciones morfológicas y funcionales claves que les permitan a estas especies crecer y persistir en su ambiente natural. Los estudios arquitecturales, y exo- y e...

  10. BAZI KÜLTÜR MANTARLARININ (Agaricus bisporus, Agaricus campestris ve Agaricus bitorquis) BESİN DEĞERİ ÜZERİNDE İNCELEMELER

    OpenAIRE

    Yalçın, Suzan; Tekinşen, O. Cenap

    1992-01-01

    This study was carried out to investigate thenutritional values of culture-mushrooms and to obtain somebasic information to increase their consumption.Agaricus bisporus, Agaricus campestris and Agaricus bltorquiswere analyzed for chemical composition.Based on the chemical analysis, the average values ofdry matter, crude protein, fat and available carbohydrate were6.31-8.87%, 2.54-3.70 %, O. 18-0.39% and 0.38-1.87%, respectively..Energy values of culture-mushrooms according to Atwatersystem we...

  11. Effects of Temperature on Systemic Infection and Symptom Expression of Turnip mosaic virus in Chinese cabbage (Brassica campestris

    Directory of Open Access Journals (Sweden)

    Bong Nam Chung

    2015-12-01

    Full Text Available Using the Chinese cabbage (Brassica campestris cultivar ‘Chun-goang’ as a host and turnip mosaic virus (TuMV as a pathogen, we studied the effects of ambient temperature (13°C, 18°C, 23°C, 28°C and 33°C on disease intensity and the speed of systemic infection. The optimal temperature for symptom expression of TuMV was 18–28°C. However, symptoms of viral infection were initiated at 23–28°C and 6 days post infection (dpi. Plants maintained at 33°C were systemically infected as early as 6 dpi and remained symptomless until 12 or 22 dpi, depending on growth stage at the time of inoculation. It took 45 days for infection of plants grown at 13°C. Quantitative real-time polymerase chain reaction (q-PCR results showed that the accumulation of virus coat protein was greater in plants grown at 23–28°C. The speed of systemic infection increased linearly with rising ambient temperature, up to 23°C. The zero-infection temperature was 10.1°C. To study the effects of abruptly elevated temperatures on systemic infection, plants inoculated with TuMV were maintained at 10°C for 20 d; transferred to a growth chamber at temperatures of 13°C, 18°C, 23°C, 28°C, or 33°C for 1, 2, or 3 d; and then moved back to 10°C. The numbers of plants infected increased as duration of exposure to higher temperatures and dpi increased.

  12. The Xanthomonas campestris pv. vesicatoria Type-3 Effector XopB Inhibits Plant Defence Responses by Interfering with ROS Production.

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    Johannes Peter Roman Priller

    Full Text Available The bacterial pathogen Xanthomonas campestris pv. vesicatoria 85-10 (Xcv translocates about 30 type-3 effector proteins (T3Es into pepper plants (Capsicum annuum to suppress plant immune responses. Among them is XopB which interferes with PTI, ETI and sugar-mediated defence responses, but the underlying molecular mechanisms and direct targets are unknown so far. Here, we examined the XopB-mediated suppression of plant defence responses in more detail. Infection of susceptible pepper plants with Xcv lacking xopB resulted in delayed symptom development compared to Xcv wild type infection concomitant with an increased formation of salicylic acid (SA and expression of pathogenesis-related (PR genes. Expression of xopB in Arabidopsis thaliana promoted the growth of the virulent Pseudomonas syringae pv. tomato (Pst DC3000 strain. This was paralleled by a decreased SA-pool and a lower induction of SA-dependent PR gene expression. The expression pattern of early flg22-responsive marker genes indicated that MAPK signalling was not altered in the presence of XopB. However, XopB inhibited the flg22-triggered burst of reactive oxygen species (ROS. Consequently, the transcript accumulation of AtOXI1, a ROS-dependent marker gene, was reduced in xopB-expressing Arabidopsis plants as well as callose deposition. The lower ROS production correlated with a low level of basal and flg22-triggered expression of apoplastic peroxidases and the NADPH oxidase RBOHD. Conversely, deletion of xopB in Xcv caused a higher production of ROS in leaves of susceptible pepper plants. Together our results demonstrate that XopB modulates ROS responses and might thereby compromise plant defence.

  13. Identification and fine mapping of a stay-green gene (Brnye1) in pakchoi (Brassica campestris L. ssp. chinensis).

    Science.gov (United States)

    Wang, Nan; Liu, Zhiyong; Zhang, Yun; Li, Chengyu; Feng, Hui

    2017-12-05

    Using bulked segregant analysis combined with next-generation sequencing, we delimited the Brnye1 gene responsible for the stay-green trait of nye in pakchoi. Sequence analysis identified Bra019346 as the candidate gene. "Stay-green" refers to a plant trait whereby leaves remain green during senescence. This trait is useful in the cultivation of pakchoi (Brassica campestris L. ssp. chinensis), which is marketed as a green leaf product. This study aimed to identify the gene responsible for the stay-green trait in pakchoi. We identified a stay-green mutant in pakchoi, which we termed "nye". Genetic analysis revealed that the stay-green trait is controlled by a single recessive gene, Brnye1. Using the BSA-seq method, a 3.0-Mb candidate region was mapped on chromosome A03, which helped us localize Brnye1 to an 81.01-kb interval between SSR markers SSRWN27 and SSRWN30 via linkage analysis in an F2 population. We identified 12 genes in this region, 11 of which were annotated based on the Brassica rapa annotation database, and one was a functionally unknown gene. An orthologous gene of the Arabidopsis gene AtNYE1, Bra019346, was identified as the potential candidate for Brnye1. Sequence analysis revealed a 40-bp insertion in the second exon of Bra019346 in nye, which generated the TAA stop codon. A candidate gene-specific Indel marker in 1561 F2 individuals showed perfect cosegregation with Brnye1 in the nye mutant. These results provide a foundation for uncovering the molecular mechanism of the stay-green trait in pakchoi.

  14. Purification and Characterization of OleA from Xanthomonas campestris and Demonstration of a Non-decarboxylative Claisen Condensation Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Frias, JA; Richman, JE; Erickson, JS; Wackett, LP

    2011-03-25

    OleA catalyzes the condensation of fatty acyl groups in the first step of bacterial long-chain olefin biosynthesis, but the mechanism of the condensation reaction is controversial. In this study, OleA from Xanthomonas campestris was expressed in Escherichia coli and purified to homogeneity. The purified protein was shown to be active with fatty acyl-CoA substrates that ranged from C(8) to C(16) in length. With limiting myristoyl-CoA (C(14)), 1 mol of the free coenzyme A was released/mol of myristoyl-CoA consumed. Using [(14)C] myristoyl-CoA, the other products were identified as myristic acid, 2-myristoylmyristic acid, and 14-heptacosanone. 2-Myristoylmyristic acid was indicated to be the physiologically relevant product of OleA in several ways. First, 2-myristoylmyristic acid was the major condensed product in short incubations, but over time, it decreased with the concomitant increase of 14-heptacosanone. Second, synthetic 2-myristoylmyristic acid showed similar decarboxylation kinetics in the absence of OleA. Third, 2-myristoylmyristic acid was shown to be reactive with purified OleC and OleD to generate the olefin 14-heptacosene, a product seen in previous in vivo studies. The decarboxylation product, 14-heptacosanone, did not react with OleC and OleD to produce any demonstrable product. Substantial hydrolysis of fatty acyl-CoA substrates to the corresponding fatty acids was observed, but it is currently unclear if this occurs in vivo. In total, these data are consistent with OleA catalyzing a non-decarboxylative Claisen condensation reaction in the first step of the olefin biosynthetic pathway previously found to be present in at least 70 different bacterial strains.

  15. Increased ELISA sensitivity using a modified extraction buffer for detection of Xanthomonas campestris pv. vesicatoria in leaf tissue.

    Science.gov (United States)

    Jones, J B; Somodi, G C; Scott, J W

    1997-10-01

    In vitro and in planta sensitivity of an indirect enzyme-linked immunoassay technique, using a monoclonal antibody specific for the lipopolysaccharide (LPS) of Xanthomonas campestris pv. vesicatoria, was increased 10-fold by using a new extraction buffer (gl of: KH2PO4, 2; NaHPO4, 11.5; EDTA disodium, 0.14; thimerosal, 0.02; and lysozyme, 0.2). The procedure improved sensitivity without increasing background levels. In vitro, the limit of detection was between 1 x 10(7) and 1 x 10(8) cells ml-1 with the conventional extraction buffer phosphate-buffered saline (PBS) and less than 1 x 10(6) cells ml-1 when lysozyme extraction buffer was substituted for PBS. In comparing 22 X. c. vesicatoria strains, absorbance readings were increased close to three-fold with the lysozyme extraction buffer as opposed to PBS. When leaf tissue extract was spiked with the bacterium, the limit of detection was 1 x 10(7) cfu ml-1 and 1 x 10(8) cfu ml-1 with the lysozyme solution and PBS, respectively, as the extraction buffers. When using the lysozyme extraction buffer in combination with a commercial amplification system, the limit of detection was decreased to less than 1 x 10(5) cfu ml-1 in leaf tissue. The addition of the lysozyme and EDTA to the phosphate buffer resulted in release of a significant quantity of LPS and concomitant dramatic increase in sensitivity. The new procedure, termed lysozyme ELISA (L-ELISA), should increase sensitivity of ELISA reactions where LPS is the reacting epitope.

  16. A generalised PID-type control scheme with simple tuning for the global regulation of robot manipulators with constrained inputs

    Science.gov (United States)

    Mendoza, Marco; Zavala-Río, Arturo; Santibáñez, Víctor; Reyes, Fernando

    2015-10-01

    In this paper, a globally stabilising PID-type control scheme with a generalised saturating structure for robot manipulators under input constraints is proposed. It gives rise to various families of bounded PID-type controllers whose implementation is released from the exact knowledge of the system parameters and model structure. Compared to previous approaches of the kind, the proposed scheme is not only characterised by its generalised structure but also by its very simple tuning criterion, the simplest hitherto obtained in the considered analytical framework. Experimental results on a 3-degree-of-freedom direct-drive manipulator corroborate the efficiency of the proposed approach.

  17. Implications of Spatiotemporal Regulation of Shigella flexneri Type Three Secretion Activity on Effector Functions: Think Globally, Act Locally.

    Science.gov (United States)

    Campbell-Valois, F-X; Pontier, Stéphanie M

    2016-01-01

    Shigella spp. are Gram-negative bacterial pathogens that infect human colonic epithelia and cause bacterial dysentery. These bacteria express multiple copies of a syringe-like protein complex, the Type Three Secretion apparatus (T3SA), which is instrumental in the etiology of the disease. The T3SA triggers the plasma membrane (PM) engulfment of the bacteria by host cells during the initial entry process. It then enables bacteria to escape the resulting phagocytic-like vacuole. Freed bacteria form actin comets to move in the cytoplasm, which provokes bacterial collision with the inner leaflet of the PM. This phenomenon culminates in T3SA-dependent secondary uptake and vacuolar rupture in neighboring cells in a process akin to what is observed during entry and named cell-to-cell spread. The activity of the T3SA of Shigella flexneri was recently demonstrated to display an on/off regulation during the infection. While the T3SA is active when bacteria are in contact with PM-derived compartments, it switches to an inactive state when bacteria are released within the cytosol. These observations indicate that effector proteins transiting through the T3SA are therefore translocated in a highly time and space constrained fashion, likely impacting on their cellular distribution. Herein, we present what is currently known about the composition, the assembly and the regulation of the T3SA activity and discuss the consequences of the on/off regulation of T3SA on Shigella effector properties and functions during the infection. Specific examples that will be developed include the role of effectors IcsB and VirA in the escape from LC3/ATG8-positive vacuoles formed during cell-to-cell spread and of IpaJ protease activity against N-miristoylated proteins. The conservation of a similar regulation of T3SA activity in other pathogens such as Salmonella or Enteropathogenic Escherichia coli will also be briefly discussed.

  18. MarA, SoxS and Rob of Escherichia coli - Global regulators of multidrug resistance, virulence and stress response.

    Science.gov (United States)

    Duval, Valérie; Lister, Ida M

    2013-01-01

    Bacteria have a great capacity for adjusting their metabolism in response to environmental changes by linking extracellular stimuli to the regulation of genes by transcription factors. By working in a co-operative manner, transcription factors provide a rapid response to external threats, allowing the bacteria to survive. This review will focus on transcription factors MarA, SoxS and Rob in Escherichia coli, three members of the AraC family of proteins. These homologous proteins exemplify the ability to respond to multiple threats such as oxidative stress, drugs and toxic compounds, acidic pH, and host antimicrobial peptides. MarA, SoxS and Rob recognize similar DNA sequences in the promoter region of more than 40 regulatory target genes. As their regulons overlap, a finely tuned adaptive response allows E. coli to survive in the presence of different assaults in a co-ordinated manner. These regulators are well conserved amongst Enterobacteriaceae and due to their broad involvement in bacterial adaptation in the host, have recently been explored as targets to develop new anti-virulence agents. The regulators are also being examined for their roles in novel technologies such as biofuel production.

  19. Allelopatic effect of different caster bean organs (Ricinus communis L. on reducing germination and growth of dodder (Cuscuta campestris Yuncker

    Directory of Open Access Journals (Sweden)

    S.M Seyyedi

    2016-05-01

    Full Text Available Introduction Dodder (Cascuta campestris Yuncker is an annual parasitic plant from the Convolvulaceae family (Mishra et al., 2007. It wraps around many adjacent dicot and a few monocot plants, penetrates in their vascular tissue and exploits photosynthates, nutrients and water (Lanini & Kogan, 2005. Consequently, the growth, vigor and production of the host plant will be severely reduced (Nadler-Hasasr & Rubin, 2003. Dodder is not able to complete its cycle, if it is not attached to a host. Therefore, it is entirely dependent on its host for supplying water, assimilates and minerals (Mishra et al., 2007. Considering the nature of dodder habit, it is rarely possible to completely control dodder by using different chemical herbicides (Lanini & Kogan, 2005. In addition, because of increasing the environmental concerns caused by applying synthetic herbicides, there is considerable attention to alternative strategies for weeds management (Batish et al., 2002; Bowmik & Inderjit, 2003. In recent years, allelopathic plants, an alternative strategy for weed management, have received massive attention (Narwal, 2010; Jamil et al., 2009. Due to the importance of dodder as a parasitic weed, this research was conducted with the purpose of studying the allelopathic effects of aqueous extracts and decay durations of caster bean (Ricinus communis L. organs on germination and emergence of dodder. Materials and methods The current study was conducted based on three separate experiments using a completely randomized design (CRD with factorial arrangement with three replications. The first experiment was conducted in petri dishes and consisted of caster bean organs at four levels (root, stem, leaf and total plant without inflorescence and their aqueous extract concentrations at 11 levels (0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10%. The second experiment was conducted in pots and factors were caster bean organs at 4 levels (root, stem, leaf and total plant without

  20. Modulating the Global Response Regulator, LuxO of V. cholerae Quorum Sensing System Using a Pyrazine Dicarboxylic Acid Derivative (PDCApy: An Antivirulence Approach

    Directory of Open Access Journals (Sweden)

    M. Hema

    2017-10-01

    Full Text Available Vibrio cholerae is a Gram-negative pathogen which causes acute diarrhoeal disease, cholera by the expression of virulence genes through quorum sensing (QS mechanism. The QS circuit of V. cholerae is controlled by the global quorum regulator, LuxO, which at low cell density (LCD state produces major virulence factors such as, toxin co-regulated pilus (TCP and cholera toxin (CT to mediate infection. On the contrary, at the high cell density (HCD state the virulent genes are downregulated and the vibrios are detached from the host intestinal epithelial cells, promoted by HapA protease. Hence, targeting the global regulator LuxO would be a promising approach to modulate the QS to curtail V. cholerae pathogenesis. In our earlier studies, LuxO targeted ligand, 2,3 pyrazine dicarboxylic acid (PDCA and its derivatives having desired pharmacophore properties were chemically synthesized and were shown to have biofilm inhibition as well as synergistic activity with the conventionally used antibiotics. In the present study, the QS modulatory effect of the PDCA derivative with pyrrolidine moiety designated as PDCApy against the V. cholerae virulence gene expression was analyzed at various growth phases. The data significantly showed a several fold reduction in the expression of the genes, tcp and ct whereas the expression of hapR was upregulated at the LCD state. In addition, PDCApy reduced the adhesion and invasion of the vibrios onto the INT407 intestinal cell lines. Collectively, our data suggest that PDCApy could be a potential QS modulator (QSM for the antivirulence therapeutic approach.

  1. Seleção de genótipos de pimentão resistentes à Xanthomonas campestris pv. vesicatoria (Doidge Dye. sob condições naturais de infecção Selection of pepper genotypes resistant to Xanthomonas campestris pv. vesicatoria (Doidge Dye. under natural condictions of plant infection

    Directory of Open Access Journals (Sweden)

    Hiroshi Noda

    2003-01-01

    Full Text Available Devido à ocorrência de epidemias severas de pústula bacteriana ou mancha bacteriana no pimentão, causada pela bactéria Xanthomonas campestris pv. vesicatoria (Doidge Dye., o cultivo do pimentão na várzea do Rio Solimões, próximo à Manaus, encontra-se em decadência. O INPA, desde 1976, desenvolve um Programa de Melhoramento Genético do Pimentão visando incorporar resistência ao patógeno. Neste trabalho são relatados os resultados obtidos em três ensaios, nas áreas de terra firme e várzea do Estado do Amazonas, envolvendo progênies F13 e F14 do cruzamento interespecífico entre Capsicum annuum e C. chinense, denominado HP-12, em cujas progênies vêm sendo realizadas seleções genealógicas visando obter variedades resistentes ao patógeno X. campestris pv. vesicatoria e alta capacidade produtiva, sob condição de cultivo em ambientes quentes e úmidos. Quando a população de hospedeiros foi constituída por indivíduos resistentes e suscetíveis, a curva de progresso da doença adaptou-se melhor ao modelo monomolecular, onde níveis mais elevados de resistência, conferidos por um genótipo, foram devidos à sua capacidade de restringir a velocidade do progresso da doença. Nos três ensaios, as progênies selecionadas pelo Programa apresentaram maior resistência e capacidade produtiva, quando comparadas à testemunha suscetível (Cascadura Ikeda, em condições de ocorrência da doença e verificou-se que a capacidade de produção de frutos está relacionada aos níveis de resistência do hospedeiro ao patógeno. Por outro lado, levando-se em conta os caracteres de resistência e capacidade produtiva das progênies inferiu-se que a espécie C. chinense é um recurso genético importante como fonte de resistência a X. campestris pv. vesicatoria nos programas de melhoramento do pimentão.The cultivation of pepper is decling in the floodplain ecosystem of the Solimões River, near Manaus, Amazonas, Brazil, because the

  2. Global protein conjugation by ubiquitin-like-modifiers during ischemic stress is regulated by microRNAs and confers robust tolerance to ischemia.

    Directory of Open Access Journals (Sweden)

    Yang-ja Lee

    Full Text Available Hibernation torpor provides an excellent model of natural tolerance to ischemia. We have previously shown that massive global SUMOylation occurs during hibernation torpor in ground squirrels. We have also shown that overexpression of Ubc9, SUMO-1, or SUMO-2/3 provides protection against ischemic damage in cell lines and cortical neurons exposed to oxygen/glucose deprivation, and in mice exposed to middle cerebral artery occlusion. We have now extended our study to other Ubiquitin-Like-Modifiers (ULMs, which have multiple cellular functions during stress, in order to assess the possibility that they also have roles in tolerance to ischemia. We found that not only SUMO conjugation, but also global protein conjugation by other ULMs including NEDD8, ISG15, UFM1 and FUB1 were significantly increased in the brains of hibernating ground squirrels during torpor. By means of miRNA microarrays of ground squirrel brain samples (from active and torpor phase we found that the miR-200 family (miR-200a,b,c/miR-141/miR-429 and the miR-182 family (miR-182/miR-183/miR-96 were among the most consistently depressed miRNAs in the brain during the torpor phase as compared to active animals. In addition, we showed that these miRNAs are involved in the expression of various ULM proteins and their global conjugation to proteins. We observed that inhibition of the miR-200 family and/or miR-182 family miRNA activities in SHSY5Y cells increases global protein conjugation by the above ULMs and makes these cells more tolerant to OGD-induced cell death. This is the first report to describe that the natural tolerance to brain ischemia in hibernators is linked to regulation by microRNAs of a broad range of ubiquitin-like modifiers.

  3. Global Metabolic Regulation of the Snow Alga Chlamydomonas nivalis in Response to Nitrate or Phosphate Deprivation by a Metabolome Profile Analysis

    Directory of Open Access Journals (Sweden)

    Na Lu

    2016-05-01

    Full Text Available In the present work, Chlamydomonas nivalis, a model species of snow algae, was used to illustrate the metabolic regulation mechanism of microalgae under nutrient deprivation stress. The seed culture was inoculated into the medium without nitrate or phosphate to reveal the cell responses by a metabolome profile analysis using gas chromatography time-of-flight mass spectrometry (GC/TOF-MS. One hundred and seventy-one of the identified metabolites clustered into five groups by the orthogonal partial least squares discriminant analysis (OPLS-DA model. Among them, thirty of the metabolites in the nitrate-deprived group and thirty-nine of the metabolites in the phosphate-deprived group were selected and identified as “responding biomarkers” by this metabolomic approach. A significant change in the abundance of biomarkers indicated that the enhanced biosynthesis of carbohydrates and fatty acids coupled with the decreased biosynthesis of amino acids, N-compounds and organic acids in all the stress groups. The up- or down-regulation of these biomarkers in the metabolic network provides new insights into the global metabolic regulation and internal relationships within amino acid and fatty acid synthesis, glycolysis, the tricarboxylic acid cycle (TCA and the Calvin cycle in the snow alga under nitrate or phosphate deprivation stress.

  4. Effects of BPA on global DNA methylation and global histone 3 lysine modifications in SH-SY5Y cells: An epigenetic mechanism linking the regulation of chromatin modifiying genes.

    Science.gov (United States)

    Senyildiz, Mine; Karaman, Ecem Fatma; Bas, Serap Sancar; Pirincci, Pelin Arda; Ozden, Sibel

    2017-10-01

    Bisphenol A (BPA), an estrogenic endocrine disruptor, is widely used in the production of polycarbonate plastic and epoxy resins, resulting in high risk on human health. In present study we aimed to investigate the effects of BPA on global and gene specific DNA methylation, global histone modifications and regulation of chromatin modifiying enzymes in human neuroblastoma cells (SH-SY5Y). Cells were treated with BPA at 0.1, 1 and 10μM concentrations for 48 and 96h. IC50 value of BPA was determined as 183 and 129μM in SH-SY5Y cells after 24h by MTT and NRU tests, respectively. We observed significant alterations on the 5-mC% levels (1.3 fold) and 5-hmC% levels (1.67 fold) after 10μM of BPA for 96h. Significant decrease was identified in H3K9me3 and H3K9ac after 10μM of BPA for 96h while decrease was observed in H3K4me3 at 10μM of BPA for 48h. Alterations were observed in chromatin modifiying genes including G9a, EZH2, SETD8, SETD1A, HAT1, SIRT1, DNMT1, RIZ1 and Suv39h1 after 96h of BPA exposure. Taken together, this study suggests that BPA might modulate the epigenetic regulators which would be key molecular events in the toxicity of endocrine disrupting chemicals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Affected pathways and transcriptional regulators in gene expression response to an ultra-marathon trail: Global and independent activity approaches.

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    Maria Maqueda

    Full Text Available Gene expression (GE analyses on blood samples from marathon and half-marathon runners have reported significant impacts on the immune and inflammatory systems. An ultra-marathon trail (UMT represents a greater effort due to its more testing conditions. For the first time, we report the genome-wide GE profiling in a group of 16 runners participating in an 82 km UMT competition. We quantified their differential GE profile before and after the race using HuGene2.0st microarrays (Affymetrix Inc., California, US. The results obtained were decomposed by means of an independent component analysis (ICA targeting independent expression modes. We observed significant differences in the expression levels of 5,084 protein coding genes resulting in an overrepresentation of 14% of the human biological pathways from the Kyoto Encyclopedia of Genes and Genomes database. These were mainly clustered on terms related with protein synthesis repression, altered immune system and infectious diseases related mechanisms. In a second analysis, 27 out of the 196 transcriptional regulators (TRs included in the Open Regulatory Annotation database were overrepresented. Among these TRs, we identified transcription factors from the hypoxia-inducible factors (HIF family EPAS1 (p< 0.01 and HIF1A (p<0.001, and others jointly described in the gluconeogenesis program such as HNF4 (p< 0.001, EGR1 (p<0.001, CEBPA (p< 0.001 and a highly specific TR, YY1 (p<0.01. The five independent components, obtained from ICA, further revealed a down-regulation of 10 genes distributed in the complex I, III and V from the electron transport chain. This mitochondrial activity reduction is compatible with HIF-1 system activation. The vascular endothelial growth factor (VEGF pathway, known to be regulated by HIF, also emerged (p<0.05. Additionally, and related to the brain rewarding circuit, the endocannabinoid signalling pathway was overrepresented (p<0.05.

  6. Arabidopsis plastid AMOS1/EGY1 integrates abscisic acid signaling to regulate global gene expression response to ammonium stress

    KAUST Repository

    Li, Baohai

    2012-10-12

    Ammonium (NH4 +) is a ubiquitous intermediate of nitrogen metabolism but is notorious for its toxic effects on most organisms. Extensive studies of the underlying mechanisms of NH4 + toxicity have been reported in plants, but it is poorly understood how plants acclimate to high levels of NH4 +. Here, we identified an Arabidopsis (Arabidopsis thaliana) mutant, ammonium overly sensitive1 (amos1), that displays severe chlorosis under NH4 + stress. Map-based cloning shows amos1 to carry a mutation in EGY1 (for ethylene-dependent, gravitropism-deficient, and yellow-green-like protein1), which encodes a plastid metalloprotease. Transcriptomic analysis reveals that among the genes activated in response to NH4 +, 90% are regulated dependent on AMOS1/ EGY1. Furthermore, 63% of AMOS1/EGY1-dependent NH4 +-activated genes contain an ACGTG motif in their promoter region, a core motif of abscisic acid (ABA)-responsive elements. Consistent with this, our physiological, pharmacological, transcriptomic, and genetic data show that ABA signaling is a critical, but not the sole, downstream component of the AMOS1/EGY1-dependent pathway that regulates the expression of NH4 +-responsive genes and maintains chloroplast functionality under NH4 + stress. Importantly, abi4 mutants defective in ABA-dependent and retrograde signaling, but not ABA-deficient mutants, mimic leaf NH4 + hypersensitivity of amos1. In summary, our findings suggest that an NH4 +-responsive plastid retrograde pathway, which depends on AMOS1/EGY1 function and integrates with ABA signaling, is required for the regulation of expression of the presence of high NH4 + levels. © 2012 American Society of Plant Biologists. All Rights Reserved.

  7. Implications of Spatiotemporal Regulation of Shigella flexneri Type Three Secretion Activity on Effector Functions: Think Globally, Act Locally

    Science.gov (United States)

    Campbell-Valois, F.-X.; Pontier, Stéphanie M.

    2016-01-01

    Shigella spp. are Gram-negative bacterial pathogens that infect human colonic epithelia and cause bacterial dysentery. These bacteria express multiple copies of a syringe-like protein complex, the Type Three Secretion apparatus (T3SA), which is instrumental in the etiology of the disease. The T3SA triggers the plasma membrane (PM) engulfment of the bacteria by host cells during the initial entry process. It then enables bacteria to escape the resulting phagocytic-like vacuole. Freed bacteria form actin comets to move in the cytoplasm, which provokes bacterial collision with the inner leaflet of the PM. This phenomenon culminates in T3SA-dependent secondary uptake and vacuolar rupture in neighboring cells in a process akin to what is observed during entry and named cell-to-cell spread. The activity of the T3SA of Shigella flexneri was recently demonstrated to display an on/off regulation during the infection. While the T3SA is active when bacteria are in contact with PM-derived compartments, it switches to an inactive state when bacteria are released within the cytosol. These observations indicate that effector proteins transiting through the T3SA are therefore translocated in a highly time and space constrained fashion, likely impacting on their cellular distribution. Herein, we present what is currently known about the composition, the assembly and the regulation of the T3SA activity and discuss the consequences of the on/off regulation of T3SA on Shigella effector properties and functions during the infection. Specific examples that will be developed include the role of effectors IcsB and VirA in the escape from LC3/ATG8-positive vacuoles formed during cell-to-cell spread and of IpaJ protease activity against N-miristoylated proteins. The conservation of a similar regulation of T3SA activity in other pathogens such as Salmonella or Enteropathogenic Escherichia coli will also be briefly discussed. PMID:27014638

  8. Implications of Spatiotemporal Regulation of Shigella flexneri Type three Secretion Activity on Effector Functions: think globally, act locally

    Directory of Open Access Journals (Sweden)

    F-X eCampbell-Valois

    2016-03-01

    Full Text Available Shigella spp. are Gram-negative bacterial pathogens that infect human colonic epithelia and cause bacterial dysentery. These bacteria express multiple copies of a syringe-like protein complex, the Type Three Secretion apparatus (T3SA, which is instrumental in the etiology of the disease. The T3SA triggers the plasma membrane (PM engulfment of the bacteria by host cells during the initial entry process. It then enables bacteria to escape the resulting phagocytic-like vacuole. Freed bacteria form actin comets to move in the cytoplasm, which provokes bacterial collision with the inner leaflet of the PM. This phenomenon culminates in T3SA-dependent secondary uptake and vacuolar rupture in neighboring cells in a process akin to what is observed during entry and named cell-to-cell spread. The activity of the T3SA of Shigella flexneri was recently demonstrated to display an on/off regulation during the infection. While the T3SA is active when bacteria are in contact with PM-derived compartments, it switches to an inactive state when bacteria are released within the cytosol. These observations indicate that effector proteins transiting through the T3SA are therefore translocated in a highly time and space constrained fashion, likely impacting on their cellular distribution. Herein, we present what is currently known about the composition, the assembly and the regulation of the T3SA activity and discuss the consequences of the on/off regulation of T3SA on Shigella effector properties and functions during the infection. Specific examples that will be developed include the role of effectors IcsB and VirA in the escape from LC3/ATG8-positive vacuoles formed during cell-to-cell spread and of IpaJ protease activity against N-miristoylated proteins. The conservation of a similar regulation of T3SA activity in other pathogens such as Salmonella or Enteropathogenic Escherichia coli will also be briefly discussed.

  9. Identification of Astrotactin2 as a Genetic Modifier That Regulates the Global Orientation of Mammalian Hair Follicles.

    Directory of Open Access Journals (Sweden)

    Hao Chang

    Full Text Available Planar cell polarity (PCP signaling controls the global orientation of surface structures, such as hairs and bristles, in both vertebrates and invertebrates. In Frizzled6(-/- (Fz6(-/- mice, hair follicle orientations on the head and back are nearly random at birth, but reorient during early postnatal development to eventually generate a nearly parallel anterior-to-posterior array. We report the identification of a naturally occurring exon 5 deletion in Astrotactin2 (Astn2 that acts as a recessive genetic modifier of the Fz6(-/- hair patterning phenotype. A genetically engineered Astn2 exon 5 deletion recapitulates the modifier phenotype. In Fz6(-/-;Astn2(ex5del/del mice, hair orientation on the back is subtly biased from posterior-to-anterior, leading to a 180-degree orientation reversal in mature mice. These experiments suggest that Astn2, an endosomal membrane protein, modulates PCP signaling.

  10. Pancreatic atrophy caused by dietary selenium deficiency induces hypoinsulinemic hyperglycemia via global down-regulation of selenoprotein encoding genes in broilers.

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    Jingyang Xu

    Full Text Available This study was envisaged to comprehensively profile genes in selected tissues along with a few biochemical indicators and integrate resulting information with dietary selenium (Se deficiency symptoms in broilers. A total of 120 one-day-old Cobb male broilers were equally divided into two groups and fed a Se deficient corn-soybean-based basal diet supplemented with 0.3 mg/kg sodium selenite (Control, Se adequate or without selenite (Se deficiency for five weeks. Effects of Se deficiency on mRNA abundance of twenty-three selenoprotein encoding genes and seventeen insulin signaling related genes were studied at day 35 in pancreas, liver and muscle along with plasma biochemical constituents and enzyme activities. Compared to healthy birds in control diet, Se deficient diet induced deficiency symptoms in 90% birds and classic nutritional pancreatic atrophy, depressed growth performance of broilers, and decreased (P < 0.01 to P < 0.05 total antioxidant capacity and activities of superoxide dismutase and glutathione peroxidase in plasma and three other tissues. Se deficiency resulted in 58% higher mortality than control birds. Dietary Se deficiency down-regulated (P < 0.01-0.05 eighteen selenoprotein encoding genes in pancreas, fourteen genes in muscle and nine genes in liver, and up-regulated (P < 0.05 Txnrd1 and Selx in liver. Meanwhile, six, thirteen and five insulin signaling related genes were down-regulated (P < 0.01-0.05 in pancreas, muscle and liver, respectively, and three genes were up-regulated (P < 0.01 in liver. The decrease (P < 0.05 in levels of plasma insulin, total triglyceride and total cholesterol, and concurrent elevated (P < 0.05 levels of plasma glucose and inflammatory cytokines accompanied the global down-regulation of selenoprotein encoding- and insulin signaling related- genes in Se deficient birds. It was concluded that dietary Se deficiency induces nutritional pancreatic atrophy and metabolic disorder of glucose and lipid in

  11. SUMO: regulating the regulator

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    Bossis Guillaume

    2006-06-01

    Full Text Available Abstract Post-translational modifiers of the SUMO (Small Ubiquitin-related Modifier family have emerged as key regulators of protein function and fate. While the past few years have seen an enormous increase in knowledge on SUMO enzymes, substrates, and consequences of modification, regulation of SUMO conjugation is far from being understood. This brief review will provide an overview on recent advances concerning (i the interplay between sumoylation and other post-translational modifications at the level of individual targets and (ii global regulation of SUMO conjugation and deconjugation.

  12. Evidence for a role for the gumB and gumC gene products in the formation of xanthan from its pentasaccharide repeating unit by Xanthomonas campestris.

    Science.gov (United States)

    Vojnov, A A; Zorreguieta, A; Dow, J M; Daniels, M J; Dankert, M A

    1998-06-01

    The biosynthesis of the extracellular polysaccharide xanthan in Xanthomonas campestris pv. campestris is directed by a cluster of 12 genes, gumB-gumM. Several xanthan-deficient mutants of the wild-type strain 8004 have previously been described which carry Tn5 insertions in this region of the chromosome. Here it is shown that the transposon insertion in one of these mutants, strain 8397, is located 15 bp upstream of the translational start site of the gumB gene. EDTA-treated cells of strain 8397 were able to synthesize the lipid-linked pentasaccharide repeating unit of xanthan from the three nucleotide sugar donors (UDP-glucose, GDP-mannose and UDP-glucuronic acid) but were unable to polymerize the pentasaccharide into mature xanthan. A subclone of the gum gene cluster carrying gumB and gumC restored xanthan production to strain 8397 to levels approximately 28% of the wild-type. In contrast, subclones carrying gumB or gumC alone were not effective. These results are discussed with reference to previous speculations, based on computer analysis, that gumB and gumC are both involved in the translocation of xanthan across the bacterial membranes.

  13. Biological Functions of ilvC in Branched-Chain Fatty Acid Synthesis and Diffusible Signal Factor Family Production in Xanthomonas campestris

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    Kai-Huai Li

    2017-12-01

    Full Text Available In bacteria, the metabolism of branched-chain amino acids (BCAAs is tightly associated with branched-chain fatty acids (BCFAs synthetic pathways. Although previous studies have reported on BCFAs biosynthesis, more detailed associations between BCAAs metabolism and BCFAs biosynthesis remain to be addressed. In this study, we deleted the ilvC gene, which encodes ketol-acid reductoisomerase in the BCAAs synthetic pathway, from the Xanthomonas campestris pv. campestris (Xcc genome. We characterized gene functions in BCFAs biosynthesis and production of the diffusible signal factor (DSF family signals. Disruption of ilvC caused Xcc to become auxotrophic for valine and isoleucine, and lose the ability to synthesize BCFAs via carbohydrate metabolism. Furthermore, ilvC mutant reduced the ability to produce DSF-family signals, especially branched-chain DSF-family signals, which might be the main reason for Xcc reduction of pathogenesis toward host plants. In this report, we confirmed that BCFAs do not have major functions in acclimatizing Xcc cells to low temperatures.

  14. Amplified fragment length polymorphism and multilocus sequence analysis-based genotypic relatedness among pathogenic variants of Xanthomonas citri pv. citri and Xanthomonas campestris pv. bilvae.

    Science.gov (United States)

    Bui Thi Ngoc, Lan; Vernière, Christian; Jouen, Emmanuel; Ah-You, Nathalie; Lefeuvre, Pierre; Chiroleu, Frédéric; Gagnevin, Lionel; Pruvost, Olivier

    2010-03-01

    Three pathogenic variants (i.e. pathotypes) have been described within Xanthomonas citri pv. citri, the causal agent of Asiatic citrus canker. Pathotype A strains naturally infect a wide range of Citrus species and members of some related genera. In contrast, pathotypes A* and A(w) have narrow host ranges within the genus Citrus and have been isolated from Mexican lime (Citrus aurantifolia L.) and from Mexican lime and alemow (Citrus macrophylla L.), respectively. We used amplified fragment length polymorphism (AFLP) and multilocus sequence analysis (MLSA) based on four partial housekeeping gene sequences (atpD, dnaK, efp and gyrB ) for the genotypic classification of Xanthomonas citri pv. citri and the poorly characterized citrus pathogen Xanthomonas campestris pv. bilvae. A Mantel test showed that genetic distances derived from AFLP and MLSA were highly correlated. X. campestris pv. bilvae showed a close relatedness to the type strain of X. citri, indicating that this pathovar should be reclassified as X. citri pv. bilvae. All pathotype A* and A(w) strains were most closely related to X. citri pv. citri strains with a wide host range (pathotype A), confirming previous DNA-DNA hybridization data. Pathotype A(w) should be considered a junior synonym of pathotype A* on the basis of pathogenicity tests, AFLP, MLSA and PCR using pathovar-specific primers. Evolutionary genome divergences computed from AFLP data suggested that pathotype A* (including A(w) strains) is a group of strains that shows a wider genetic diversity than pathotype A.

  15. Molecular cloning and expression analysis of a Cu/Zn SOD gene (BcCSD1) from Brassica campestris ssp. chinensis.

    Science.gov (United States)

    Cui, Lijie; Huang, Qiang; Yan, Bin; Wang, Yao; Qian, Zhongyin; Pan, Jingxian; Kai, Guoyin

    2015-11-01

    Superoxide dismutases (SODs) are a family of metalloproteins extensively exists in eukaryote, which plays an essential role in stress-tolerance of higher plants. A full-length cDNA encoding Cu/Zn SOD (BcCSD1) was isolated from young seedlings of non-heading Chinese cabbage (Brassica campestris ssp. chinensis) by rapid amplification of cDNA ends (RACE). Bioinformatics analysis revealed that BcCSD1 belonged to the plant SOD super family and had the closest relationship with SOD from Brassica napus. Tissue expression pattern analysis revealed that the BcCSD1 was constitutively expressed in all the tested tissues, and strongest in leaf, moderate in stem, lowest in root. The expression profiles under different stress treatments such as drought, NaCl, high temperature and ABA were also investigated, and the results revealed that BcCSD1 was a stress-responsive gene, especially to ABA. These results provide useful information for further understanding the role of BcCSD1 resistant to abiotic stress in Brassica campestris in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Homology modeling, molecular docking and MD simulation studies to investigate role of cysteine protease from Xanthomonas campestris in degradation of Aβ peptide.

    Science.gov (United States)

    Dhanavade, Maruti J; Jalkute, Chidambar B; Barage, Sagar H; Sonawane, Kailas D

    2013-12-01

    Cysteine protease is known to degrade amyloid beta peptide which is a causative agent of Alzheimer's disease. This cleavage mechanism has not been studied in detail at the atomic level. Hence, a three-dimensional structure of cysteine protease from Xanthomonas campestris was constructed by homology modeling using Geno3D, SWISS-MODEL, and MODELLER 9v7. All the predicted models were analyzed by PROCHECK and PROSA. Three-dimensional model of cysteine protease built by MODELLER 9v7 shows similarity with human cathepsin B crystal structure. This model was then used further for docking and simulation studies. The molecular docking study revealed that Cys17, His87, and Gln88 residues of cysteine protease form an active site pocket similar to human cathepsin B. Then the docked complex was refined by molecular dynamic simulation to confirm its stable behavior over the entire simulation period. The molecular docking and MD simulation studies showed that the sulfhydryl hydrogen atom of Cys17 of cysteine protease interacts with carboxylic oxygen of Lys16 of Aβ peptide indicating the cleavage site. Thus, the cysteine protease model from X. campestris having similarity with human cathepsin B crystal structure may be used as an alternate approach to cleave Aβ peptide a causative agent of Alzheimer's disease. © 2013 Elsevier Ltd. All rights reserved.

  17. Alleviation of cadmium toxicity to Cole (Brassica campestris L. Cruciferae) by exogenous glutathione

    Science.gov (United States)

    Wang, Jun; Huang, Bin; Chen, Xin; Shi, Yi

    2017-04-01

    In this study, we determined the influence of exogenous GSH on cadmium toxicity to cole. GSH addition had beneficial effect on plant development and growth, especially on aboveground biomass and root length. Despite that exogenous GSH insignificantly promoted Cd uptake by the plant, it could decrease of Cd root-to-shoot transport and ameliorate Cd toxicity to the plant. At 6 mg Cd kg-1 soil, GSH addition well countered the Cd-induced significant reduction in CAT activity, but only insignificantly decreased MDA content, suggesting exogenous GSH might indirectly protect plant against oxidative stress via regulating antioxidative enzyme activities. However, at 12 mg Cd kg-1 soil, GSH application insignificantly increased the antioxidant activities but significantly decreased MDA content, indicating external GSH could directly participate in removing radical oxygen species. The results suggest exogenous GSH may have the potential of decreasing Cd accumulation in the edible parts of cultivars and alleviating Cd toxicity.

  18. Regulated mRNA Decay in Arabidopsis: A global analysis of differential control by hormones and the circadian clock

    Energy Technology Data Exchange (ETDEWEB)

    Green, Pamela J. [Univ. of Delaware, Newark, DE (United States)

    2010-03-18

    The long-term goal of this research was to better understand the influence of mRNA stability on gene regulation, particularly in response to hormones and the circadian clock. The primary aim of this project was to examine this using DNA microarrays, small RNA analysis and other approaches. We accomplished these objectives, although we were only able to detect small changes in mRNA stability in response to these stimuli. However, the work also contributed to a major breakthrough allowing the identification of small RNAs on a genomic scale in eukaryotes. Moreover, the project prompted us to develop a new way to analyze mRNA decay genome wide. Thus, the research was hugely successful beyond our objectives.

  19. Global gene analysis identifying genes commonly regulated by the Ras/Raf/MEK and type I IFN pathways.

    Science.gov (United States)

    Komatsu, Y; Hirasawa, K; Christian, S L

    2015-06-01

    Oncolytic viruses exploit alterations in cancer cells to specifically infect cancer cells but not normal healthy cells. Previous work has shown that oncogenic Ras interferes with interferon (IFN) signaling to promote viral replication. Furthermore, inhibition of the Ras/Raf/MEK/ERK pathway at the level of Ras, MEK, or ERK was sufficient to restore IFN signaling. In order to identify genes that were commonly regulated by the inhibition of the Ras pathway and the IFN pathway, we treated NIH/3T3 cells that overexpress oncogenic Ras with the MEK inhibitor, U0126, or IFN-α for 6 h, and performed DNA microarray analysis (Gene Expression Omnibus accession number GSE49469). Here, we also provide additional information on the experimental and functional analysis of the genes responsive to U0126 and IFN.

  20. Deep sequencing analysis of small noncoding RNA and mRNA targets of the global post-transcriptional regulator, Hfq.

    Directory of Open Access Journals (Sweden)

    Alexandra Sittka

    2008-08-01

    Full Text Available Recent advances in high-throughput pyrosequencing (HTPS technology now allow a thorough analysis of RNA bound to cellular proteins, and, therefore, of post-transcriptional regulons. We used HTPS to discover the Salmonella RNAs that are targeted by the common bacterial Sm-like protein, Hfq. Initial transcriptomic analysis revealed that Hfq controls the expression of almost a fifth of all Salmonella genes, including several horizontally acquired pathogenicity islands (SPI-1, -2, -4, -5, two sigma factor regulons, and the flagellar gene cascade. Subsequent HTPS analysis of 350,000 cDNAs, derived from RNA co-immunoprecipitation (coIP with epitope-tagged Hfq or control coIP, identified 727 mRNAs that are Hfq-bound in vivo. The cDNA analysis discovered new, small noncoding RNAs (sRNAs and more than doubled the number of sRNAs known to be expressed in Salmonella to 64; about half of these are associated with Hfq. Our analysis explained aspects of the pleiotropic effects of Hfq loss-of-function. Specifically, we found that the mRNAs of hilD (master regulator of the SPI-1 invasion genes and flhDC (flagellar master regulator were bound by Hfq. We predicted that defective SPI-1 secretion and flagellar phenotypes of the hfq mutant would be rescued by overexpression of HilD and FlhDC, and we proved this to be correct. The combination of epitope-tagging and HTPS of immunoprecipitated RNA detected the expression of many intergenic chromosomal regions of Salmonella. Our approach overcomes the limited availability of high-density microarrays that have impeded expression-based sRNA discovery in microorganisms. We present a generic strategy that is ideal for the systems-level analysis of the post-transcriptional regulons of RNA-binding proteins and for sRNA discovery in a wide range of bacteria.

  1. The DtxR protein acting as dual transcriptional regulator directs a global regulatory network involved in iron metabolism of Corynebacterium glutamicum

    Directory of Open Access Journals (Sweden)

    Hüser Andrea T

    2006-02-01

    Full Text Available Abstract Background The knowledge about complete bacterial genome sequences opens the way to reconstruct the qualitative topology and global connectivity of transcriptional regulatory networks. Since iron is essential for a variety of cellular processes but also poses problems in biological systems due to its high toxicity, bacteria have evolved complex transcriptional regulatory networks to achieve an effective iron homeostasis. Here, we apply a combination of transcriptomics, bioinformatics, in vitro assays, and comparative genomics to decipher the regulatory network of the iron-dependent transcriptional regulator DtxR of Corynebacterium glutamicum. Results A deletion of the dtxR gene of C. glutamicum ATCC 13032 led to the mutant strain C. glutamicum IB2103 that was able to grow in minimal medium only under low-iron conditions. By performing genome-wide DNA microarray hybridizations, differentially expressed genes involved in iron metabolism of C. glutamicum were detected in the dtxR mutant. Bioinformatics analysis of the genome sequence identified a common 19-bp motif within the upstream region of 31 genes, whose differential expression in C. glutamicum IB2103 was verified by real-time reverse transcription PCR. Binding of a His-tagged DtxR protein to oligonucleotides containing the 19-bp motifs was demonstrated in vitro by DNA band shift assays. At least 64 genes encoding a variety of physiological functions in iron transport and utilization, in central carbohydrate metabolism and in transcriptional regulation are controlled directly by the DtxR protein. A comparison with the bioinformatically predicted networks of C. efficiens, C. diphtheriae and C. jeikeium identified evolutionary conserved elements of the DtxR network. Conclusion This work adds considerably to our currrent understanding of the transcriptional regulatory network of C. glutamicum genes that are controlled by DtxR. The DtxR protein has a major role in controlling the

  2. Regulation of plasmid-encoded isoprene metabolism in Rhodococcus, a representative of an important link in the global isoprene cycle.

    Science.gov (United States)

    Crombie, Andrew T; Khawand, Myriam El; Rhodius, Virgil A; Fengler, Kevin A; Miller, Michael C; Whited, Gregg M; McGenity, Terry J; Murrell, J Colin

    2015-09-01

    Emissions of biogenic volatile organic compounds (VOCs) form an important part of the global carbon cycle, comprising a significant proportion of net ecosystem productivity. They impact atmospheric chemistry and contribute directly and indirectly to greenhouse gases. Isoprene, emitted largely from plants, comprises one third of total VOCs, yet in contrast to methane, which is released in similar quantities, we know little of its biodegradation. Here, we report the genome of an isoprene degrading isolate, Rhodococcus sp. AD45, and, using mutagenesis shows that a plasmid-encoded soluble di-iron centre isoprene monooxygenase (IsoMO) is essential for isoprene metabolism. Using RNA sequencing (RNAseq) to analyse cells exposed to isoprene or epoxyisoprene in a substrate-switch time-course experiment, we show that transcripts from 22 contiguous genes, including those encoding IsoMO, were highly upregulated, becoming among the most abundant in the cell and comprising over 25% of the entire transcriptome. Analysis of gene transcription in the wild type and an IsoMO-disrupted mutant strain showed that epoxyisoprene, or a subsequent product of isoprene metabolism, rather than isoprene itself, was the inducing molecule. We provide a foundation of molecular data for future research on the environmental biological consumption of this important, climate-active compound. © 2015 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Output-Feedback Adaptive SP-SD-Type Control with an Extended Continuous Adaptation Algorithm for the Global Regulation of Robot Manipulators with Bounded Inputs

    Directory of Open Access Journals (Sweden)

    Daniela J. López-Araujo

    2013-01-01

    Full Text Available In this work, an output-feedback adaptive SP-SD-type control scheme for the global position stabilization of robot manipulators with bounded inputs is proposed. Compared with the output-feedback adaptive approaches previously developed in a bounded-input context, the proposed velocity-free feedback controller guarantees the adaptive regulation objective globally (i.e. for any initial condition, avoiding discontinuities throughout the scheme, preventing the inputs from reaching their natural saturation bounds and imposing no saturation-avoidance restrictions on the choice of the P and D control gains. Moreover, through its extended structure, the adaptation algorithm may be configured to evolve either in parallel (independently or interconnected to the velocity estimation (motion dissipation auxiliary dynamics, giving an additional degree of design flexibility. Furthermore, the proposed scheme is not restricted to the use of a specific saturation function to achieve the required boundedness, but may involve any one within a set of smooth and non-smooth (Lipschitz-continuous bounded passive functions that include the hyperbolic tangent and the conventional saturation as particular cases. Experimental results on a 3-degree-of-freedom manipulator corroborate the efficiency of the proposed scheme.

  4. The ShcA Phosphotyrosine Docking Protein Uses Distinct Mechanisms to Regulate Myocyte and Global Heart Function

    Science.gov (United States)

    Vanderlaan, Rachel D.; Hardy, W. Rod; Kabir, M. Golam; Pasculescu, Adrian; Jones, Nina; deTombe, Pieter P.; Backx, Peter H.; Pawson, Tony

    2011-01-01

    Rationale Although tyrosine kinases (TKs) are important for cardiac function, their relevant downstream targets in the adult heart are unknown. The ShcA docking protein binds specific phosphotyrosine (pTyr) sites on activated TKs through its N-terminal pTyr-binding (PTB) and C-terminal SH2 domains and stimulates downstream pathways through motifs such as pTyr sites in its central CH1 region. Therefore, ShcA could be a potential hub for downstream TK signaling in the myocardium. Objective To define the role of ShcA, a TK scaffold, in the adult heart using a myocardial-specific knockout of murine ShcA (ShcA CKO) and domain knock-in models. Methods and Results ShcA CKO mice developed a dilated cardiomyopathy phenotype involving impaired systolic function with enhanced cardiomyocyte contractility. This uncoupling of global heart and intrinsic myocyte functions was associated with altered collagen and extracellular matrix compliance properties, suggesting disruption of mechanical coupling. In vivo dissection of ShcA signaling properties revealed that selective inactivation of the PTB domain in the myocardium had effects resembling those seen in ShcA CKO mice, whereas disruption of the SH2 domain caused a less severe cardiac phenotype. Downstream signaling through the CH1 pTyr sites was dispensable for baseline cardiac function but necessary to prevent adverse remodeling after hemodynamic overload. Conclusions These data demonstrate a requirement for TK-ShcA PTB domain signaling to maintain cardiac function. In addition, analysis of the SH2 domain and CH1 pTyr sites reveals that ShcA mediates pTyr signaling in the adult heart through multiple distinct signaling elements that control myocardial functions and response to stresses. PMID:21148430

  5. Modulation of global low-frequency motions underlies allosteric regulation: demonstration in CRP/FNR family transcription factors.

    Directory of Open Access Journals (Sweden)

    Thomas L Rodgers

    2013-09-01

    Full Text Available Allostery is a fundamental process by which ligand binding to a protein alters its activity at a distinct site. There is growing evidence that allosteric cooperativity can be communicated by modulation of protein dynamics without conformational change. The mechanisms, however, for communicating dynamic fluctuations between sites are debated. We provide a foundational theory for how allostery can occur as a function of low-frequency dynamics without a change in structure. We have generated coarse-grained models that describe the protein backbone motions of the CRP/FNR family transcription factors, CAP of Escherichia coli and GlxR of Corynebacterium glutamicum. The latter we demonstrate as a new exemplar for allostery without conformation change. We observe that binding the first molecule of cAMP ligand is correlated with modulation of the global normal modes and negative cooperativity for binding the second cAMP ligand without a change in mean structure. The theory makes key experimental predictions that are tested through an analysis of variant proteins by structural biology and isothermal calorimetry. Quantifying allostery as a free energy landscape revealed a protein "design space" that identified the inter- and intramolecular regulatory parameters that frame CRP/FNR family allostery. Furthermore, through analyzing CAP variants from diverse species, we demonstrate an evolutionary selection pressure to conserve residues crucial for allosteric control. This finding provides a link between the position of CRP/FNR transcription factors within the allosteric free energy landscapes and evolutionary selection pressures. Our study therefore reveals significant features of the mechanistic basis for allostery. Changes in low-frequency dynamics correlate with allosteric effects on ligand binding without the requirement for a defined spatial pathway. In addition to evolving suitable three-dimensional structures, CRP/FNR family transcription factors have

  6. Global Regulation of the Response to Sulfur Availability in the Cheese-Related Bacterium Brevibacterium aurantiacum▿ †

    Science.gov (United States)

    Forquin, Marie-Pierre; Hébert, Agnès; Roux, Aurélie; Aubert, Julie; Proux, Caroline; Heilier, Jean-François; Landaud, Sophie; Junot, Christophe; Bonnarme, Pascal; Martin-Verstraete, Isabelle

    2011-01-01

    In this study, we combined metabolic reconstruction, growth assays, and metabolome and transcriptome analyses to obtain a global view of the sulfur metabolic network and of the response to sulfur availability in Brevibacterium aurantiacum. In agreement with the growth of B. aurantiacum in the presence of sulfate and cystine, the metabolic reconstruction showed the presence of a sulfate assimilation pathway, thiolation pathways that produce cysteine (cysE and cysK) or homocysteine (metX and metY) from sulfide, at least one gene of the transsulfuration pathway (aecD), and genes encoding three MetE-type methionine synthases. We also compared the expression profiles of B. aurantiacum ATCC 9175 during sulfur starvation or in the presence of sulfate. Under sulfur starvation, 690 genes, including 21 genes involved in sulfur metabolism and 29 genes encoding amino acids and peptide transporters, were differentially expressed. We also investigated changes in pools of sulfur-containing metabolites and in expression profiles after growth in the presence of sulfate, cystine, or methionine plus cystine. The expression of genes involved in sulfate assimilation and cysteine synthesis was repressed in the presence of cystine, whereas the expression of metX, metY, metE1, metE2, and BL613, encoding a probable cystathionine-γ-synthase, decreased in the presence of methionine. We identified three ABC transporters: two operons encoding transporters were transcribed more strongly during cysteine limitation, and one was transcribed more strongly during methionine depletion. Finally, the expression of genes encoding a methionine γ-lyase (BL929) and a methionine transporter (metPS) was induced in the presence of methionine in conjunction with a significant increase in volatile sulfur compound production. PMID:21169450

  7. The water channel protein aquaporin 1 regulates cellular metabolism and competitive fitness in a global fungal pathogen Cryptococcus neoformans.

    Science.gov (United States)

    Meyers, Gena Lee; Jung, Kwang-Woo; Bang, Soohyun; Kim, Jungyeon; Kim, Sooah; Hong, Joohyeon; Cheong, Eunji; Kim, Kyoung Heon; Bahn, Yong-Sun

    2017-06-01

    In this study, an aquaporin protein, Aqp1, in Cryptococcus neoformans, which can lead either saprobic or parasitic lifestyles and causes life-threatening fungal meningitis was identified and characterized. AQP1 expression was rapidly induced (via the HOG pathway) by osmotic or oxidative stress. In spite of such transcriptional regulation, Aqp1 was found to be largely unnecessary for adaptation to diverse environmental stressors, regardless of the presence of the polysaccharide capsule. The latter is shown here to be a key environmental-stress protectant for C. neoformans. Furthermore, Aqp1 was not required for the development and virulence of C. neoformans. Deletion of AQP1 increased hydrophobicity of the cell surface. The comparative metabolic profiling analysis of the aqp1Δ mutant and AQP1-overexpressing strains revealed that deletion of AQP1 significantly increased cellular accumulation of primary and secondary metabolites, whereas overexpression of AQP1 depleted such metabolites, suggesting that this water channel protein performs a critical function in metabolic homeostasis. In line with this result, it was found that the aqp1Δ mutant (which is enriched with diverse metabolites) survived better than the wild type and a complemented strain, indicating that Aqp1 is likely to be involved in competitive fitness of this fungal pathogen. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Host-selected mutations converging on a global regulator drive an adaptive leap towards symbiosis in bacteria

    Science.gov (United States)

    Sabrina Pankey, M; Foxall, Randi L; Ster, Ian M; Perry, Lauren A; Schuster, Brian M; Donner, Rachel A; Coyle, Matthew; Cooper, Vaughn S; Whistler, Cheryl A

    2017-01-01

    Host immune and physical barriers protect against pathogens but also impede the establishment of essential symbiotic partnerships. To reveal mechanisms by which beneficial organisms adapt to circumvent host defenses, we experimentally evolved ecologically distinct bioluminescent Vibrio fischeri by colonization and growth within the light organs of the squid Euprymna scolopes. Serial squid passaging of bacteria produced eight distinct mutations in the binK sensor kinase gene, which conferred an exceptional selective advantage that could be demonstrated through both empirical and theoretical analysis. Squid-adaptive binK alleles promoted colonization and immune evasion that were mediated by cell-associated matrices including symbiotic polysaccharide (Syp) and cellulose. binK variation also altered quorum sensing, raising the threshold for luminescence induction. Preexisting coordinated regulation of symbiosis traits by BinK presented an efficient solution where altered BinK function was the key to unlock multiple colonization barriers. These results identify a genetic basis for microbial adaptability and underscore the importance of hosts as selective agents that shape emergent symbiont populations. DOI: http://dx.doi.org/10.7554/eLife.24414.001 PMID:28447935

  9. Efeito do tratamento de bacelos de videira 'Red Globe' no controle do cancro bacteriano causado por Xanthomonas campestris pv. viticola

    Directory of Open Access Journals (Sweden)

    Carine Rosa Naue

    2014-12-01

    Full Text Available A disseminação de Xanthomonas campestris pv. viticola (Xcv, agente do cancro bacteriano da videira, ocorre, dentre outras formas, por meio de mudas e bacelos infectados. Foi estudada a obtenção de material propagativo livre do patógeno, testando a eficiência do tratamento de bacelos com termoterapia, bactericidas e sanitizantes. Os isolados de Xcv foram testados quanto à patogenicidade e realizado o teste de sensibilidade in vitro aos produtos, em diferentes concentrações. A erradicação de Xcv em bacelos de videira foi testada em experimentos com termoterapia (50ºC por 30 e 40 min; 53ºC por 5 e 10 min; bactericidas [oxitetraciclina+sulfato de cobre (150+2.000; 165+2.200; 180+2.400 e 195+2.600 mg L-1 de H2O e oxitetraciclina (600; 700; 800 e 900 mg L-1]; e sanitizantes [cloreto de dodecildimetil amônio (600; 1.200; 1.800; 2.400 e 3.000 µL L-1; hipoclorito de sódio (5.000; 10.000; 20.000; 30.000 e 40.000 µL L-1 e cloreto de benzalcônio (125; 167;250; 334 e 500 µL L-1]. Foram avaliados período de incubação, incidência e severidade da doença. O bactericida oxitetraciclina e os sanitizantes cloreto de dodecildimetil amônio e hipoclorito de sódio proporcionaram os maiores halos de inibição de Xcv in vitro. No entanto, apesar dos diversos tratamentos testados, não foi possível recomendar tratamento termoterápico ou produto que erradicasse Xcv de bacelos infectados. Porém, ficou confirmada a grande importância destes na disseminação do agente do cancro bacteriano da videira.

  10. Regulatory Elements Located in the Upstream Region of the Rhizobium leguminosarum rosR Global Regulator Are Essential for Its Transcription and mRNA Stability

    Directory of Open Access Journals (Sweden)

    Kamila Rachwał

    2017-12-01

    Full Text Available Rhizobium leguminosarum bv. trifolii is a soil bacterium capable of establishing a symbiotic relationship with clover (Trifolium spp.. Previously, the rosR gene, encoding a global regulatory protein involved in motility, synthesis of cell-surface components, and other cellular processes was identified and characterized in this bacterium. This gene possesses a long upstream region that contains several regulatory motifs, including inverted repeats (IRs of different lengths. So far, the role of these motifs in the regulation of rosR transcription has not been elucidated in detail. In this study, we performed a functional analysis of these motifs using a set of transcriptional rosR-lacZ fusions that contain mutations in these regions. The levels of rosR transcription for different mutant variants were evaluated in R. leguminosarum using both quantitative real-time PCR and β-galactosidase activity assays. Moreover, the stability of wild type rosR transcripts and those with mutations in the regulatory motifs was determined using an RNA decay assay and plasmids with mutations in different IRs located in the 5′-untranslated region of the gene. The results show that transcription of rosR undergoes complex regulation, in which several regulatory elements located in the upstream region and some regulatory proteins are engaged. These include an upstream regulatory element, an extension of the -10 element containing three nucleotides TGn (TGn-extended -10 element, several IRs, and PraR repressor related to quorum sensing.

  11. Global patterns of gene regulation associated with the development of ectomycorrhiza between birch (Betula pendula Roth.) and Paxillus involutus (Batsch) Fr.

    Science.gov (United States)

    Le Quéré, Antoine; Wright, Derek P; Söderström, Bengt; Tunlid, Anders; Johansson, Tomas

    2005-07-01

    The formation of ectomycorrhizal (ECM) root tissue is characterized by distinct morphological and developmental stages, such as preinfection and adhesion, mantle, and Hartig net formation. The global pattern of gene expression during these stages in the birch (Betula pendula)-Paxillus involutus ECM association was analyzed using cDNA microarrays. In comparison with nonsymbiotic conditions, 251 fungal (from a total of 1,075) and 138 plant (1,074 in total) genes were found to be differentially regulated during the ECM development. For instance, during mantle and Hartig net development, there were several plant genes upregulated that are normally involved in defense responses during pathogenic fungal challenges. These responses were, at later stages of ECM development, found to be repressed. Other birch genes that showed differential regulation involved several homologs that usually are implicated in water permeability (aquaporins) and water stress tolerance (dehydrins). Among fungal genes differentially upregulated during stages of mantle and Hartig net formation were homologs putatively involved in mitochondrial respiration. In fully developed ECM tissue, there was an upregulation of fungal genes related to protein synthesis and the cytoskeleton assembly machinery. This study highlights complex molecular interactions between two symbionts during the development of an ECM association.

  12. Global regulation of virulence and the stress response by CsrA in the highly adapted human gastric pathogen Helicobacter pylori

    DEFF Research Database (Denmark)

    Barnard, F.M.; Loughlin, M.F.; Fainberg, H.P.

    2004-01-01

    -induced transcriptional responses of napA and ahpC, the acid induction of napA, cagA, vacA, the urease operon, and fur, as well as the heat shock responses of napA, groESL and hspR. Although the level of napA transcript was higher in the csrA mutant, its stability was similar in the wild-type and mutant strains, and less....... We therefore investigated the contribution of the regulatory protein CsrA to global gene regulation in this important human pathogen. CsrA was necessary for full motility and survival of H. pylori under conditions of oxidative stress. Loss of csrA expression deregulated the oxidant...... NapA protein was produced in the mutant strain. Finally, H. pylori strains deficient in the production of CsrA were significantly attenuated for virulence in a mouse model of infection. This work provides evidence that CsrA has a broad role in regulating the physiology of H. pylori in response...

  13. A direct link between the global regulator PhoP and the Csr regulon in Y. pseudotuberculosis through the small regulatory RNA CsrC.

    Science.gov (United States)

    Nuss, Aaron M; Schuster, Franziska; Kathrin Heroven, Ann; Heine, Wiebke; Pisano, Fabio; Dersch, Petra

    2014-01-01

    In this study we investigated the influence of the global response regulator PhoP on the complex regulatory cascade controlling expression of early stage virulence genes of Yersinia pseudotuberculosis via the virulence regulator RovA. Our analysis revealed the following novel features: (1) PhoP activates expression of the CsrC RNA in Y. pseudotuberculosis, leading to activation of RovA synthesis through the CsrABC-RovM cascade, (2) activation of csrC transcription is direct and PhoP is shown to bind to two separate PhoP box-like sites, (3) PhoP-mediated activation results in transcription from two different promoters closely downstream of the PhoP binding sites, leading to two distinct CsrC RNAs, and (4) the stability of the CsrC RNAs differs significantly between the Y. pseudotuberculosis strains YPIII and IP32953 due to a 20 nucleotides insertion in CsrC(IP32953), which renders the transcript more susceptible to degradation. In summary, our study showed that PhoP-mediated influence on the regulatory cascade controlling the Csr system and RovA in Y. pseudotuberculosis varies within the species, suggesting that the Csr system is a focal point to readjust and adapt the genus to different hosts and reservoirs.

  14. Global regulator IscR positively contributes to antimonite resistance and oxidation in Comamonas testosterone S44

    Directory of Open Access Journals (Sweden)

    Hongliang eLiu

    2015-12-01

    Full Text Available Antimonial compounds can be found as a toxic contaminant in the environment. Mechanisms of microbial Sb oxidation and its role in microbial tolerance are limited. Previously, we showed Comamonas testosteroni S44 to be resistant to multiple heavy metals and was able to oxidize the toxic antimonite [Sb(III] to the much less toxic antimonate [Sb(V]. In this study, transposon mutagenesis was performed in C. testosteroni S44 to isolate genes responsible for Sb(III resistance and oxidation. An insertion mutation into iscR, which regulates genes involved in the biosynthesis of Fe-S clusters, generated a strain called iscR-280. This mutant strain was complemented with a plasmid carrying iscR to generate strain iscR-280C. Compared to the wild type S44 and iscR-280C, strain iscR-280 showed lower resistance to Sb(III and a lower Sb(III oxidation rate. Strain iscR-280 also showed lower resistance to As(III, Cd(II, Cu(II and H2O2. In addition, intracellular γ-glutamylcysteine ligase (γ-GCL activity and glutathione (GSH content were decreased in the mutated strain iscR-280. Real-time RT-PCR and lacZ fusion expression assay indicated that transcription of iscR and iscS was induced by Sb(III. Results of electrophoretic mobility shift assay (EMSA and bacterial one-hybrid (B1H system demonstrated a positive interaction between IscR and its promoter region. The diverse defective phenotypes and various expression patterns suggested a role for IscR in contributing to multi-metal(loids resistance and Sb(III oxidation via Fe-S cluster biogenesis and oxidative stress protection. Bacterial Sb(III oxidation is a detoxification reaction.

  15. Rhizosphere competent Mesorhizobiumloti MP6 induces root hair curling, inhibits Sclerotinia sclerotiorum and enhances growth of Indian mustard (Brassica campestris Mesorhizobium loti MP6 rizosférico competente induz encurvamento do pelo daraiz, inibe Sclerotinia sclerotiorum e estimula o crescimento de mostarda indiana (Brassica campestris

    Directory of Open Access Journals (Sweden)

    Shikha Chandra

    2007-03-01

    Full Text Available The bacterial strain Mesorhizobium loti MP6, isolated from root nodules of Mimosa pudica induced growth and yield of Brassica campestris. The isolate MP6 secreted hydroxamate type siderophore in Chrom-Azurol Siderophore (CAS agar medium. Production of hydrocyanic acid (HCN, indole acetic acid (IAA and phosphate solubilizing ability was also recorded under normal growth conditions. Root hair curling was observed through simple glass-slide technique. In vitro study showed a significant increase in population of M. loti MP6 in rhizosphere due to root exudates of B. campestris. In dual culture technique the strain showed a strong antagonistic effect against Sclerotinia sclerotiorum, a white rot pathogen of Brassica campestris. The growth of S. sclerotiorum was inhibited by 75% after prolonged incubation. Efficient root colonization of mustard seedlings was confirmed by using a streptomycin-resistant marker M. loti MP6strep+. The M. loti MP6 coated seeds proved enhanced seed germination, early vegetative growth and grain yield as compared to control. Also, a drastic decline (99% in the incidence of white rot was observed due to application of M. loti MP6.A cepa bacteriana Mesorhizobium loti MP6 isolada de nódulos de raiz de Mimosa pudica induziu o crescimento e o rendimento de Brassica campestris. A cepa MP6 secretou sideróforo do tipo hidroxamato em meio sólido Chrom-Azurol Siderophore (CAS. Em condições normais de crescimento, a cepa foi também capaz de produzir de ácido cianídrico (HCN e acido indolacético (AIA e solubilizar fosfato. O encurvamento do pelo da raiz foi observado usando a simples técnica de lâmina e lamínula. Estudos in vitro mostraram um aumento significativo na população de M. loti MP6 na rizosfera devido aos exsudatos de B. campestris. Empregando-se técnica de co-cultura, a cepa mostrou um grande efeito antagônico contra o fungo Sclerotinia sclerotiorum, o patógeno da podridão branca de Brassica campestris. Ap

  16. Global gene expression in muscle from fasted/refed trout reveals up-regulation of genes promoting myofibre hypertrophy but not myofibre production.

    Science.gov (United States)

    Rescan, Pierre-Yves; Le Cam, Aurelie; Rallière, Cécile; Montfort, Jérôme

    2017-06-07

    Compensatory growth is a phase of rapid growth, greater than the growth rate of control animals, that occurs after a period of growth-stunting conditions. Fish show a capacity for compensatory growth after alleviation of dietary restriction, but the underlying cellular mechanisms are unknown. To learn more about the contribution of genes regulating hypertrophy (an increase in muscle fibre size) and hyperplasia (the generation of new muscle fibres) in the compensatory muscle growth response in fish, we used high-density microarray analysis to investigate the global gene expression in muscle of trout during a fasting-refeeding schedule and in muscle of control-fed trout displaying normal growth. The compensatory muscle growth signature, as defined by genes up-regulated in muscles of refed trout compared with control-fed trout, showed enrichment in functional categories related to protein biosynthesis and maturation, such as RNA processing, ribonucleoprotein complex biogenesis, ribosome biogenesis, translation and protein folding. This signature was also enriched in chromatin-remodelling factors of the protein arginine N-methyl transferase family. Unexpectedly, functional categories related to cell division and DNA replication were not inferred from the molecular signature of compensatory muscle growth, and this signature contained virtually none of the genes previously reported to be up-regulated in hyperplastic growth zones of the late trout embryo myotome and to potentially be involved in production of new myofibres, notably genes encoding myogenic regulatory factors, transmembrane receptors essential for myoblast fusion or myofibrillar proteins predominant in nascent myofibres. Genes promoting myofibre growth, but not myofibre formation, were up-regulated in muscles of refed trout compared with continually fed trout. This suggests that a compensatory muscle growth response, resulting from the stimulation of hypertrophy but not the stimulation of hyperplasia

  17. RegA, an AraC-Like Protein, Is a Global Transcriptional Regulator That Controls Virulence Gene Expression in Citrobacter rodentium▿

    Science.gov (United States)

    Hart, Emily; Yang, Ji; Tauschek, Marija; Kelly, Michelle; Wakefield, Matthew J.; Frankel, Gad; Hartland, Elizabeth L.; Robins-Browne, Roy M.

    2008-01-01

    Citrobacter rodentium is an attaching and effacing pathogen which causes transmissible colonic hyperplasia in mice. Infection with C. rodentium serves as a model for infection of humans with enteropathogenic and enterohemorrhagic Escherichia coli. To identify novel colonization factors of C. rodentium, we screened a signature-tagged mutant library of C. rodentium in mice. One noncolonizing mutant had a single transposon insertion in an open reading frame (ORF) which we designated regA because of its homology to genes encoding members of the AraC family of transcriptional regulators. Deletion of regA in C. rodentium resulted in markedly reduced colonization of the mouse intestine. Examination of lacZ transcriptional fusions using promoter regions of known and putative virulence-associated genes of C. rodentium revealed that RegA strongly stimulated transcription of two newly identified genes located close to regA, which we designated adcA and kfcC. The cloned adcA gene conferred autoaggregation and adherence to mammalian cells to E. coli strain DH5α, and a kfc mutation led to a reduction in the duration of intestinal colonization, but the kfc mutant was far less attenuated than the regA mutant. These results indicated that other genes of C. rodentium whose expression required activation by RegA were required for colonization. Microarray analysis revealed a number of RegA-regulated ORFs encoding proteins homologous to known colonization factors. Transcription of these putative virulence determinants was activated by RegA only in the presence of sodium bicarbonate. Taken together, these results show that RegA is a global regulator of virulence in C. rodentium which activates factors that are required for intestinal colonization. PMID:18765720

  18. RegA, an AraC-like protein, is a global transcriptional regulator that controls virulence gene expression in Citrobacter rodentium.

    Science.gov (United States)

    Hart, Emily; Yang, Ji; Tauschek, Marija; Kelly, Michelle; Wakefield, Matthew J; Frankel, Gad; Hartland, Elizabeth L; Robins-Browne, Roy M

    2008-11-01

    Citrobacter rodentium is an attaching and effacing pathogen which causes transmissible colonic hyperplasia in mice. Infection with C. rodentium serves as a model for infection of humans with enteropathogenic and enterohemorrhagic Escherichia coli. To identify novel colonization factors of C. rodentium, we screened a signature-tagged mutant library of C. rodentium in mice. One noncolonizing mutant had a single transposon insertion in an open reading frame (ORF) which we designated regA because of its homology to genes encoding members of the AraC family of transcriptional regulators. Deletion of regA in C. rodentium resulted in markedly reduced colonization of the mouse intestine. Examination of lacZ transcriptional fusions using promoter regions of known and putative virulence-associated genes of C. rodentium revealed that RegA strongly stimulated transcription of two newly identified genes located close to regA, which we designated adcA and kfcC. The cloned adcA gene conferred autoaggregation and adherence to mammalian cells to E. coli strain DH5alpha, and a kfc mutation led to a reduction in the duration of intestinal colonization, but the kfc mutant was far less attenuated than the regA mutant. These results indicated that other genes of C. rodentium whose expression required activation by RegA were required for colonization. Microarray analysis revealed a number of RegA-regulated ORFs encoding proteins homologous to known colonization factors. Transcription of these putative virulence determinants was activated by RegA only in the presence of sodium bicarbonate. Taken together, these results show that RegA is a global regulator of virulence in C. rodentium which activates factors that are required for intestinal colonization.

  19. Functional characterization of GumK, a membrane-associated beta-glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis.

    Science.gov (United States)

    Barreras, Máximo; Abdian, Patricia L; Ielpi, Luis

    2004-03-01

    Xanthomonas campestris is a Gram-negative bacterium that produces an exopolysaccharide known as xanthan gum. Xanthan is involved in a variety of biological functions, including pathogenesis, and is widely used in the industry as thickener and viscosifier. Although the genetics and biosynthetic process of xanthan are well documented, the enzymatic components have not been examined and no data on glycosyltransferases have been reported. We describe the functional characterization of the gumK gene product, an essential protein for xanthan synthesis. Immunoblots and complementation studies showed that GumK is a 44-kDa protein associated to the membrane fraction. This value corresponds to the expected molecular mass for GumK encoded by an extended open reading frame than proposed from previous genetic data and in X. campestris published complete genome. The protein was expressed in Escherichia coli cells. The purified protein catalyzed the transfer of a glucuronic acid residue from UDP-glucuronic acid to mannose-alpha-1,3-glucose-beta-1,4-glucose-P-P-polyisoprenyl with formation of a glucuronic acid-beta-mannose linkage. We examined the acceptor substrate specificity. GumK was unable to use the trisaccharide acceptor freed from the pyrophosphate lipid moiety. Replacement of the natural lipid moiety by phytanyl showed that the catalytic function could proceed with glucuronic acid transfer. These results suggest the enzyme does not show specificity for the lipidic portion of the acceptor. GumK showed diminished activity when tested with 6-O-acetyl-mannose-alpha-1,3-glucose-beta-1,4-glucose-P-P-polyisoprenyl, a putative intermediate in the synthesis of xanthan. This could indicate that acetylation of the internal mannose takes place after the formation of the GumK product.

  20. Structure of the Full-Length Bacteriophytochrome from the Plant Pathogen Xanthomonas campestris Provides Clues to its Long-Range Signaling Mechanism.

    Science.gov (United States)

    Otero, Lisandro Horacio; Klinke, Sebastián; Rinaldi, Jimena; Velázquez-Escobar, Francisco; Mroginski, María Andrea; Fernández López, María; Malamud, Florencia; Vojnov, Adrián Alberto; Hildebrandt, Peter; Goldbaum, Fernando Alberto; Bonomi, Hernán Ruy

    2016-09-25

    Phytochromes constitute a major superfamily of light-sensing proteins that are reversibly photoconverted between a red-absorbing (Pr) and a far-red-absorbing (Pfr) state. Bacteriophytochromes (BphPs) are found among photosynthetic and non-photosynthetic bacteria, including pathogens. To date, several BphPs have been biophysically characterized. However, it is still not fully understood how structural changes are propagated from the photosensory module to the output module during the signal transduction event. Most phytochromes share a common architecture consisting of an N-terminal photosensor that includes the PAS2-GAF-PHY domain triad and a C-terminal variable output module. Here we present the crystal structure of the full-length BphP from the plant pathogen Xanthomonas campestris pv. campestris (XccBphP) bearing its photosensor and its complete output module, a PAS9 domain. In the crystals, the protein was found to be in the Pr state, whereas diffraction data together with resonance Raman spectroscopic and theoretical results indicate a ZZZssa and a ZZEssa chromophore configuration corresponding to a mixture of Pr and Meta-R state, the precursor of Pfr. The XccBphP quaternary assembly reveals a head-to-head dimer in which the output module contributes to the helical dimer interface. The photosensor, which is shown to be a bathy-like BphP, is influenced in its dark reactions by the output module. Our structural analyses suggest that the photoconversion between the Pr and Pfr states in the full-length XccBphP may involve changes in the relative positioning of the output module. This work contributes to understand the light-induced structural changes propagated from the photosensor to the output modules in phytochrome signaling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. PapR peptide maturation: role of the NprB protease in Bacillus cereus 569 PlcR/PapR global gene regulation

    Science.gov (United States)

    Pomerantsev, Andrei P.; Pomerantseva, Olga M.; Camp, Andrew S.; Mukkamala, Radhika; Goldman, Stanley; Leppla, Stephen H.

    2009-01-01

    The global transcriptional regulator PlcR controls gene expression in Bacillus cereus and Bacillus thuringiensis. Activity of PlcR is regulated by PapR, the product of an open reading frame located immediately downstream of plcR. To be active in B. cereus, PapR must be secreted and then processed to the mature peptide by an unknown protease. This peptide is transported by an oligopeptide permease into the cell where it activates PlcR. In this study, we show that the neutral protease B (NprB) secreted by B. cereus 569 is required for extracellular PapR maturation. Purified recombinant NprB processed the synthetic PapR propeptide to produce a set of peptides derived from the C-terminal domain of PapR. Supplementation of growth media with synthetic PapR-derived C-terminal 5-, 7-, 8-, and 27-amino acid peptides caused activation of intracellular PlcR in a PapR-deficient strain of B. cereus 569 while only the 5- and 7-amino acid peptides activated PlcR in a nprB mutant. The maximum activity was found for the 7-mer peptide. However, even the 7-mer peptide could not activate PlcR with a C-terminal truncation of as few as six amino acids. This indicates that interactions of the C-terminal regions of both PlcR and PapR are important in transcriptional activation of the B. cereus 569 PlcR regulon. PMID:19159431

  2. Impaired Chromatin Remodelling at STAT1-Regulated Promoters Leads to Global Unresponsiveness of Toxoplasma gondii-Infected Macrophages to IFN-γ

    Science.gov (United States)

    Lang, Christine; Hildebrandt, Anke; Brand, Franziska; Opitz, Lennart; Dihazi, Hassan; Lüder, Carsten G. K.

    2012-01-01

    Intracellular pathogens including the apicomplexan and opportunistic parasite Toxoplasma gondii profoundly modify their host cells in order to establish infection. We have shown previously that intracellular T. gondii inhibit up-regulation of regulatory and effector functions in murine macrophages (MΦ) stimulated with interferon (IFN)-γ, which is the cytokine crucial for controlling the parasites' replication. Using genome-wide transcriptome analysis we show herein that infection with T. gondii leads to global unresponsiveness of murine macrophages to IFN-γ. More than 61% and 89% of the transcripts, which were induced or repressed by IFN-γ in non-infected MΦ, respectively, were not altered after stimulation of T. gondii-infected cells with IFN-γ. These genes are involved in a variety of biological processes, which are mostly but not exclusively related to immune responses. Analyses of the underlying mechanisms revealed that IFN-γ-triggered nuclear translocation of STAT1 still occurred in Toxoplasma-infected MΦ. However, STAT1 bound aberrantly to oligonucleotides containing the IFN-γ-responsive gamma-activated site (GAS) consensus sequence. Conversely, IFN-γ did not induce formation of active GAS-STAT1 complexes in nuclear extracts from infected MΦ. Mass spectrometry of protein complexes bound to GAS oligonucleotides showed that T. gondii-infected MΦ are unable to recruit non-muscle actin to IFN-γ-responsive DNA sequences, which appeared to be independent of stimulation with IFN-γ and of STAT1 binding. IFN-γ-induced recruitment of BRG-1 and acetylation of core histones at the IFN-γ-regulated CIITA promoter IV, but not β-actin was diminished by >90% in Toxoplasma-infected MΦ as compared to non-infected control cells. Remarkably, treatment with histone deacetylase inhibitors restored the ability of infected macrophages to express the IFN-γ regulated genes H2-A/E and CIITA. Taken together, these results indicate that Toxoplasma-infected MΦ are

  3. Global harmonization of safety regulations for the use of industrial robots-permission of collaborative operation and a related study by JNIOSH.

    Science.gov (United States)

    Saito, Tsuyoshi; Hoshi, Toshiro; Ikeda, Hiroyasu; Okabe, Kohei

    2015-01-01

    In December 2013, the Japanese Ministry of Health, Labour and Welfare (MHLW) partially amended the safety regulations for use of industrial robots so that "collaborative operation" could be performed at Japanese worksites as allowed in the ISO standard for industrial robots. In order to show global harmonization of Japanese legislation on machinery safety and problems with applying ISO safety standards to Japanese worksites, this paper reports the progress of a research study which have been conducted in National Institute of Occupational Safety and Health, Japan from 2011 to the present at the request of MHLW to examine the necessity and effect of the amendment. In the first phase of this study, a questionnaire survey was conducted among domestic robot manufacturers and users. The obtained results revealed their potential demand for the collaborative operation and problems concerning their risk assessment and rule-based risk reduction. To solve the problems, we propose a method based on an investigation result of the regulatory framework for safety of machinery in the European Union. Furthermore, a model of robot system capable of demonstrating the collaborative operation and risk reduction measures which is being developed to support appropriate implementation of the amendment is also described.

  4. Global profiling of phytohormone dynamics during combined drought and pathogen stress in Arabidopsis thaliana reveals ABA and JA as major regulators.

    Science.gov (United States)

    Gupta, Aarti; Hisano, Hiroshi; Hojo, Yuko; Matsuura, Takakazu; Ikeda, Yoko; Mori, Izumi C; Senthil-Kumar, Muthappa

    2017-06-21

    Global transcriptome studies demonstrated the existence of unique plant responses under combined stress which are otherwise not seen during individual stresses. In order to combat combined stress plants use signaling pathways and 'cross talk' mediated by hormones involved in stress and growth related processes. However, interactions among hormones' pathways in combined stressed plants are not yet known. Here we studied dynamics of different hormones under individual and combined drought and pathogen infection in Arabidopsis thaliana by liquid chromatography-mass spectrometry (LC-MS) based profiling. Our results revealed abscisic acid (ABA) and salicylic acid (SA) as key regulators under individual drought and pathogen stress respectively. Under combined drought and host pathogen stress (DH) we observed non-induced levels of ABA with an upsurge in SA and jasmonic acid (JA) concentrations, underscoring their role in basal tolerance against host pathogen. Under a non-host pathogen interaction with drought (DNH) stressed plants, ABA, SA and JA profiles were similar to those under DH or non-host pathogen alone. We propose that plants use SA/JA dependent signaling during DH stress which antagonize ABA biosynthesis and signaling pathways during early stage of stress. The study provides insights into hormone modulation at different time points during combined stress.

  5. USING Xanthomonas Campestris

    African Journals Online (AJOL)

    eobe

    of three independent variables (fermentation time, nitrogen and phosphorus concentration) for optimum xanthan gum production. 2. MATERIALS AND METHODS. MATERIALS AND METHODS. MATERIALS AND METHODS. 2.1 Feedstock. 2.1 Feedstock. Pineapple peels, obtained from a local market in Benin. City, Edo ...

  6. campestris pv musacearum

    African Journals Online (AJOL)

    devastaling banana bacterial will disease (BBW). Il causes the banana fruits to prematurcly ripen, louves to will and the al'l'ected plants die leading. [0 total yicld loss. lt is such an important disease because banana supports over 70% ol' Uganda's population l'or lbod and income. Uganda has thc world's highest per capita ...

  7. Regulation of semiochemicals - Global aspects

    NARCIS (Netherlands)

    Weatherston, I.; Minks, A.K.

    1995-01-01

    A general awareness of environmental concerns, an increasing chemophobic populace and the reregistration of pesticides, both in the United States and in the European Community, with the concomitant loss of many pest control chemicals through cancellation of their registrations has provided an

  8. Arabidopsis wat1 (walls are thin1)-mediated resistance to the bacterial vascular pathogen, Ralstonia solanacearum, is accompanied by cross-regulation of salicylic acid and tryptophan metabolism.

    Science.gov (United States)

    Denancé, Nicolas; Ranocha, Philippe; Oria, Nicolas; Barlet, Xavier; Rivière, Marie-Pierre; Yadeta, Koste A; Hoffmann, Laurent; Perreau, François; Clément, Gilles; Maia-Grondard, Alessandra; van den Berg, Grardy C M; Savelli, Bruno; Fournier, Sylvie; Aubert, Yann; Pelletier, Sandra; Thomma, Bart P H J; Molina, Antonio; Jouanin, Lise; Marco, Yves; Goffner, Deborah

    2013-01-01

    Inactivation of Arabidopsis WAT1 (Walls Are Thin1), a gene required for secondary cell-wall deposition, conferred broad-spectrum resistance to vascular pathogens, including the bacteria Ralstonia solanacearum and Xanthomonas campestris pv. campestris, and the fungi Verticillium dahliae and Verticillium albo-atrum. Introduction of NahG, the bacterial salicylic acid (SA)-degrading salicylate hydroxylase gene, into the wat1 mutant restored full susceptibility to both R. solanacearum and X. campestris pv. campestris. Moreover, SA content was constitutively higher in wat1 roots, further supporting a role for SA in wat1-mediated resistance to vascular pathogens. By combining transcriptomic and metabolomic data, we demonstrated a general repression of indole metabolism in wat1-1 roots as shown by constitutive down-regulation of several genes encoding proteins of the indole glucosinolate biosynthetic pathway and reduced amounts of tryptophan (Trp), indole-3-acetic acid and neoglucobrassicin, the major form of indole glucosinolate in roots. Furthermore, the susceptibility of the wat1 mutant to R. solanacearum was partially restored when crossed with either the trp5 mutant, an over-accumulator of Trp, or Pro35S:AFB1-myc, in which indole-3-acetic acid signaling is constitutively activated. Our original hypothesis placed cell-wall modifications at the heart of the wat1 resistance phenotype. However, the results presented here suggest a mechanism involving root-localized metabolic channeling away from indole metabolites to SA as a central feature of wat1 resistance to R. solanacearum. © 2012 The Authors The Plant Journal © 2012 Blackwell Publishing Ltd.

  9. MULTIPLE INOCULATION, AND EVALUATING TECHNIQUES OF Capsicum REACTION TO THREE PATHOGENS: POTATO VIRUS Y, Phytophthora capsici AND Xanthomonas campestris pv.vesicatoria INOCULAÇÃO MÚLTIPLA E TÉCNICAS DE AVALIAÇÃO DA REAÇÃO DE Capsicum A TRÊS PATÓGENOS : VÍRUS Y DA BATATA, Phytophtora capsici E Xanthomonas campestris pv. Vesicatoria – UMA PROPOSTA

    Directory of Open Access Journals (Sweden)

    Francisco José Becker Reifschneider

    2007-09-01

    Full Text Available

    A critical analysis of the utilization of multiple inoculation with potato virus Y, Phytophthora capsici and Xamthomonas campestris pv. vesicatoria on pepper plants are shown, besides considerations and perspectives about evaluating techniques of Capsicum reaction to more than one pathogen.

    São apresentadas vantagens e desvantagens da utilização múltipla de vírus Y da batata, Phytophthora capsici e Xanthomonas campestris pv. vesicatoria em plantas de pimentão, além de considerações e perspectivas a respeito das técnicas de avaliação da reação de Capsicum a mais de um patógeno.

  10. Explicações: modos de regulação de uma atividade globalizada Private tutoring: ways of regulation of a globalized activity

    Directory of Open Access Journals (Sweden)

    António Neto-Mendes

    2008-12-01

    Full Text Available Neste artigo analisamos os modos de regulação de uma atividade - as explicações - que é hoje um caso de sucesso em todo o mundo como oferta educativa privada e que podemos mesmo considerar paralela à do modelo escolar. Num primeiro momento, procedemos à caracterização das políticas de regulação em escala global: a situação nos países que ignoram a atividade das explicações; o caso dos países que escolheram a via da proibição, total ou parcial; o caso dos países que reconheceram a atividade e até formularam políticas educacionais que encontraram nas explicações um aliado para a melhoria dos resultados escolares. Abordaremos depois a situação em Portugal, país onde a atividade existe desde há muito, mas que conhece na atualidade um vigor novo e maior visibilidade social. Quanto às políticas de regulação das explicações em Portugal, podemos falar de uma regulação burocrática sem grande eco na prática dos profissionais, dos estudantes e das famílias. Terminaremos com algumas reflexões sobre a necessidade de se dar dimensão pública à discussão sobre a atividade das explicações, tantas e tão sérias são as suas repercussões sociais e políticas, nomeadamente em matéria de democratização do acesso e do sucesso escolares, questão nuclear que está no cerne da preocupação com a equidade no seio das políticas públicas.In this text we analyze the ways of regulation of private tutoring, an activity that is at present a success story as a private educational product with an widespread use across the world that we can even see as parallel to that of the school model. Firstly, we will characterize the regulation policies that are in place worldwide: i the situation of the countries that ignore the activity of private tutoring; ii the case of the countries that have chosen to prohibit private tutoring, totally or partially; iii the case of the countries that have recognized the activity and that have

  11. Formulação de meios de cultivo à base de soro de leite para a produção de goma xantana por X. Campestris C7L Formulation of whey-based media for xanthan gum production by X. Campestris C7L isolate

    Directory of Open Access Journals (Sweden)

    Marcia NITSCHKE

    2001-01-01

    Full Text Available A goma xantana é um polissacarídeo microbiano de grande significado comercial especialmente para a indústria de alimentos. O objetivo deste trabalho foi avaliar a produção de xantana em diferentes meios de cultura à base de soro de leite utilizando o isolado Xanthomonas campestris C7L. Dentre as formulações testadas o meio de soro de leite integral produziu maior viscosidade e concentração final de xantana. Um sistema combinando soro integral (0,35% de proteína e soro filtrado (0,18%de proteína foi proposto. Na primeira fase em soro integral a produção de xantana foi de 13g/L e 45% de rendimento,enquanto que na segunda fase utilizando-se soro filtrado obteve-se um total de 28g/L de xantana e 75% de rendimento. O rendimento geral do processo foi de 55% e a viscosidade final do meio atingiu 18000cP. As soluções de xantana produzidas em soro de leite apresentaram comportamento pseudoplástico e tixotrópico característicos deste tipo de polímero. O isolado C7L demonstrou capacidade de produzir gomas de alta viscosidade e qualidade em soro de leite, constituindo uma alternativa promissora para a produção industrial de goma xantana a partir deste subproduto.Xanthan gum is a microbial polysaccharide of great commercial interest, especially in the food industry. The aim of this work was the evaluation of xanthan gum production from different whey - based media by a lactose utilizing Xanthomonas campestris C7L isolate. Three whey media formulations were tested: unfiltered whey, filtered whey and hydrolyzed whey. The medium composed of unfiltered whey showed the highest viscosities and xanthan concentrations. A two stage fermentation strategy, combining unfiltered whey (0,35% protein and filtered whey (0,18% protein, was proposed. The first stage, using unfiltered whey medium, showed a xanthan production of 12g/L and a 45% yield. The second stage, with filtered whey addition, gave final xanthan concentration of 28g/L and a 75% yield

  12. Market, Regulation, Market, Regulation

    DEFF Research Database (Denmark)

    Frankel, Christian; Galland, Jean-Pierre

    2015-01-01

    This paper focuses on the European Regulatory system which was settled both for opening the Single Market for products and ensuring the consumers' safety. It claims that the New Approach and Standardization, and the Global Approach to conformity assessment, which suppressed the last technical...... barriers to trade in Europe, realized the free movement of products by organizing progressively several orders of markets and regulation. Based on historical and institutional documents, on technical publications, and on interviews, this article relates how the European Commission and the Member States had...... alternatively recourse to markets and to regulations, at the three main levels of the New Approach Directives implementation. The article focuses also more specifically on the Medical Devices sector, not only because this New Approach sector has long been controversial in Europe, and has recently been concerned...

  13. Influence of agitation and aeration in xanthan production by Xanthomonas campestris pv pruni strain 101 Influencia de la agitación y la aireación en la producción de xantano por Xanthomonas campestris pv. pruni cepa 101

    Directory of Open Access Journals (Sweden)

    C. D. Borges

    2008-06-01

    Full Text Available Production, viscosity, and chemical composition of xanthan synthesized by bacterium Xanthomonas campestris pv pruni strain 101 were evaluated in bioreactor systems. During the process, the volumetric oxygen mass transfer coefficient (kLa and the biomass were determined and the pH was monitored. The cultures were grown in a 3 l bioreactor, with aeration and agitation varying as follows: conditions (A 300 rpm, 3 vvm and (B 200 rpm, 2 vvm, at 28 °C. Our results showed that gum production was dependent on kLa, with a maximum yield of 8.15 g/l at 300 rpm, 3 vvm, 54 h of fermentation, kLa 21.4/h, while biomass was not affected. All aqueous solutions of 3% (w/v xanthans synthesized showed a pseudoplastic behavior. The highest viscosity was reached under the strongest aeration/agitation conditions. All xanthan samples contained glucose, mannose, rhamnose, and glucuronic acid as their main components. The highest agitation and aeration rates used under condition A (300 rpm and 3 vvm favorably influenced the yield and viscosity of the xanthan produced by bacterium X. campestris pv pruni 101 at different fermentation times.Se evaluó la producción, viscosidad y composición química del xantano sintetizado por la bacteria Xanthomonas campestris pv. pruni cepa 101 en un fermentador. Durante el proceso se controló el pH y se determinaron el coeficiente de transferencia de masa de oxígeno (kLa y la producción de masa celular seca. Los cultivos se realizaron en un fermentador de 3 l variando la aireación y la agitación, en las siguientes condiciones: (A 300 rpm, 3 vvm y (B 200 rpm, 2 vvm; a 28 °C. Nuestros resultados mostraron que la producción de goma fue dependiente del kLa, con un rendimiento máximo de 8,15 g/l a 300 rpm y 3 vvm a las 54 h de fermentación, kLa de 21,4/h, mientras que la producción de biomasa no se afectó. Todas las soluciones acuosas de xantano al 3% (m/v sintetizadas presentaron comportamiento pseudoplástico. La mayor

  14. Mutation in the Xanthomonas campestris xanA gene required for synthesis of xanthan and lipopolysaccharide drastically reduces the efficiency of bacteriophage (phi)L7 adsorption.

    Science.gov (United States)

    Hung, Chih-Hsin; Wu, Hsung-Chi; Tseng, Yi-Hsiung

    2002-02-22

    (Phi)L7 is a lytic phage infecting the gram-negative Xanthomonas campestis pv. campestris, a plant pathogen. To study phage-host interaction, a (phi)L7-resistant mutant was isolated from strain Xc17 by mini-Tn5 transposition and designated CH7LR. CH7LR could not plate (phi)L7 in double-layered assay and formed turbid clearing zones when the cell lawn was dropped with a high titer of (phi)L7. Sequence analysis showed that the mutated gene is xanA coding for phosphoglucomutase/phosphomannomutase, required for the synthesis of lipopolysaccharide and exopolysaccharide (xanthan). The involvement of xanA was confirmed by isolating another mutant with interrupted xanA and complementing with the cloned wild-type gene. Nonmucoid mutants are still sensitive to (phi)L7, indicating that xanthan is not involved in (phi)L7 adsorption. Since the mutants still exhibited low efficiencies of phage adsorption, we predict, by analogy with the cases in other bacteriophages of gram-negative bacteria, that other outer membrane components such as a protein are required for the formation of a complex receptor. ©2002 Elsevier Science (USA).

  15. Production of intergeneric allotetraploid between autotetraploid non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino and autotetraploid radish (Raphanus sativus L.

    Directory of Open Access Journals (Sweden)

    Sun Cheng-Zhen

    2014-03-01

    Full Text Available Intergeneric hybrids between non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino; 2n = 4x = 40 and radish (Raphanus sativus L.; 2n = 4x = 36 were obtained through ovary culture and embryo rescue. Some hybrid embryos (0.11 per ovary were produced, but only 4 of them germinated. As most hybrid embryos failed to develop into plantlets directly, plants were regenerated by inducing shoots on the cultured cotyledon and inducing roots on the root induction medium. All hybrid plants were morphologically uniform. They resembled the non-heading Chinese cabbage in the long-lived habit, the plant status, the vernalization requirement and the petiole color, while the petiole shape, leaf venation pattern and flowers were more similar to those of radish. Upon examination of the flowers, these were found to have normal pistil, but rudimentary anthers with non-functional pollen grains. The somatic chromosome number of F1 plants was 38. Analysis of SSR banding patterns provided additional confirmation of hybridity.

  16. Effects of ambient and elevated level of ozone on Brassica campestris L. with special reference to yield and oil quality parameters.

    Science.gov (United States)

    Tripathi, Ruchika; Agrawal, S B

    2012-11-01

    Tropospheric ozone (O(3)) has become a serious threat to growth and yield of important agricultural crops over Asian regions including India. Effect of elevated O(3) (ambient+10ppb) was studied on Brassica campestris L. (cv. Sanjukta and Vardan) in open top chambers under natural field conditions. Eight hourly mean ambient O(3) concentration varied from 26.3ppb to 69.5ppb during the growth period. Plants under O(3) exposure showed reductions in photosynthetic rate, reproductive parameters, yield as well as seed and oil quality. Cultivar Sanjukta showed more reduction in photosynthetic characteristics, reproductive structures and seed and oil quality. However, total yield was more affected in Vardan. Exposure of O(3) increased the degree of unsaturation and level of PUFA, ω-6fatty acid, linolenic acid and erucic acid in oil indicating the deterioration of its quality. The study further confirmed that there is a correspondence between O(3) induced change in photosynthetic processes, reproductive development and yield and did not find any compensatory response in the final yield. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. The 9-lipoxygenase GhLOX1 gene is associated with the hypersensitive reaction of cotton Gossypium hirsutum to Xanthomonas campestris pv malvacearum.

    Science.gov (United States)

    Marmey, Philippe; Jalloul, Aïda; Alhamdia, Majd; Assigbetse, Komi; Cacas, Jean-Luc; Voloudakis, Andreas E; Champion, Antony; Clerivet, Alain; Montillet, Jean-Luc; Nicole, Michel

    2007-08-01

    Hypersensitive reaction (HR) cell death of cotton to the incompatible race 18 from Xanthomonas campestris pathovar malvacearum (Xcm) is associated with 9S-lipoxygenase activity (LOX) responsible for lipid peroxidation. Here, we report the cloning of cotton (Gossypium hirsutum L.) LOX gene (GhLOX1) and the sequencing of its promoter. GhLOX1 was found to be highly expressed during Xcm induced HR. Sequence analysis showed that GhLOX1 is a putative 9-LOX, and GhLOX1 promoter contains SA and JA responsive elements. Investigation on LOX signalisation on cotyledons infiltrated with salicylic acid (SA), or incubated with methyl-jasmonate (MeJA) revealed that both treatments induced LOX activity and GhLOX1 gene expression. HR-like symptoms were observed when LOX substrates were then injected in treated (MeJA and SA) cotyledons or when Xcm compatible race 20 was inoculated on MeJA treated cotyledons. Together these results support the fact that GhLOX1 encodes a 9 LOX whose activity would be involved in cell death during cotton HR.

  18. Relationship between Symptom Development and Actual Sites of Infection in Leaves of Anthurium Inoculated with a Bioluminescent Strain of Xanthomonas campestris pv. dieffenbachiae.

    Science.gov (United States)

    Fukui, R; Fukui, H; McElhaney, R; Nelson, S C; Alvarez, A M

    1996-03-01

    The infection process of bacterial blight of anthurium was monitored with a bioluminescent strain of Xanthomonas campestris pv. dieffenbachiae. The relationship between symptom expression on infected leaves (assessed visually) and the extent of bacterial movement within tissues (evaluated by bioluminescence emission) varied among anthurium cultivars. In several cultivars previously considered susceptible on the basis of symptom development alone, bacterial invasion of leaves extended far beyond the visually affected areas. In other cultivars previously considered resistant, bacterial invasion was restricted to areas with visible symptoms. In three cultivars previously considered resistant, leaves were extensively invaded by the bacterium, and yet few or no symptoms were seen on infected leaves. The pathogen was consistently recovered from leaf sections emitting bioluminescence but not from sections emitting no light. At an early stage of infection, no significant differences in the percentages of infected areas as determined by visual assessment were observed in any of the cultivars. However, differences among cultivars were detected by bioluminescence as the disease progressed, because bacterial invasion was not always accompanied by symptom expression. In susceptible cultivars, the advancing border of infection was 5 to 10 cm inward from the margins of the visible symptoms and often reached to the leaf petiole even when symptoms were visible in anthurium cultivars in which a nondestructive method was used to quantify the severity of leaf infection by a bioluminescent pathogen have enabled us to evaluate susceptibility and resistance to bacterial blight accurately. Such evaluations will be of importance in breeding resistant cultivars for disease control.

  19. Effects of plant growth promoting rhizobacteria (PGPR and cover crops on seed germination and early establishment of field dodder (Cuscuta campestris Yunk.

    Directory of Open Access Journals (Sweden)

    Sarić-Krsmanović Marija

    2017-01-01

    Full Text Available Several bacterial cultures: Bacillus licheniformis (MO1, B. pumilus (MO2, and B. amyloliquefaciens (MO3, isolated from manure; B. megatherium ZP6 (MO4 isolated from maize rhizosphere; Azotobacter chroococcum Ps1 (MO5 and Pseudomonas fluorescens (MO6, were used to test the influence of plant growth promoting rhizobacteria (PGPR on seed germination and germination rate of field dodder (Cuscuta campestris Yunk.. Also, to examine the effect of host seeds on germination and initial growth of seedlings of field dodder plants in the dark and under white light, the seeds of four host plants were used (watermelon, red clover, alfalfa and sugar beet. Germinated seeds were counted daily over a ten-day period and the length of seedlings was measured on the final day. The results show that treatments MO3, MO4 and MO6 had inhibitory effects (15%, 65% and 52%, respectively, while treatments MO1, MO2 and MO5 had stimulating effects (3%, 3% and 19%, respectively on seed germination of field dodder. The data for host seeds show that light was a significant initial factor (83-95%, control 95% for stimulating seed germination of field dodder plants, apart from host presence (73-79%, control 80%.

  20. Transgenic expression of the rice Xa21 pattern recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum

    Science.gov (United States)

    Tripathi, Jaindra Nath; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

    2014-01-01

    Summary Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, bio-control agents or resistant cultivars available to control BXW. Here we take advantage of the robust resistance conferred by the rice pattern recognition receptor (PRR), XA21, to the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). We identified a set of genes required for activation of Xa21 mediated immunity (rax) that were conserved in both Xoo and Xcm. Based on the conservation, we hypothesized that intergeneric transfer of Xa21 would confer resistance to Xcm. We evaluated 25 transgenic lines of the banana cultivar ‘Gonja manjaya’ (AAB) using a rapid bioassay and 12 transgenic plants in the glass house for resistance against Xcm. About fifty percent of the transgenic lines showed complete resistance to Xcm in both assays. In contrast, all of the non-transgenic control plants showed severe symptoms that progressed to complete wilting. These results indicate that the constitutive expression of the rice Xa21 gene in banana results in enhanced resistance against Xcm. Furthermore this work demonstrates the feasibility of PRR gene transfer between monocotyledonous species and provides a valuable new tool for controlling the BXW pandemic of banana, a staple food for 100 million people in east Africa. PMID:24612254

  1. Subpolítica Reflexiva no Contexto da Mundialização Informativa aplicada à Regulação Supranacional da Internet / Reflexive Sub-Politics in the context of Globalization of Information and the Internet Supranational Regulation

    Directory of Open Access Journals (Sweden)

    Bruna Pinotti Garcia

    2016-05-01

    Full Text Available Purpose – The World Wide Web is emerging not only as a mean of communication but serves as instrumental to the exercise of rights, including participation in sub-politics, so that becomes the interest of the individual put up as participatory actor in the process of discussion of its regulation. In this way, this paper addresses the following research question: Can reflective sub-politics be identified in the comparative scenario of multiple players acting in the regulation of Internet features? Methodology/approach/design – From the outset, the paper earmarks as relevant the understanding of the position of multiple players in the scenario of Internet regulation, which is possible only by supranational law comparative study contextualized with regard to sub-politics. The empirical basis of this paper lies in conferences of the United Nations, the Organization of American States, the European Union and the European Council. Its theoretical basis is focused on Ulrich Beck and Anthony Giddens and the concept of reflexive modernity associated with the policy, forming what is called reflexive sub-politics. Findings – The paper has proved the hypothesis that, regarding regulation of Internet, agendas emerge about Internet regulation that are every step less restricted to the traditional regulatory actors, allowing a greater participation of the individual in this process, with the possibility of designing sub-politics in a more simplified concept of globalization. Practical implications – The article provides to the scientific community and the society cognitive foundations necessary for inclusion of social actors in virtual spaces in the field of supranational regulation of new information technologies. Originality/value – The terms globalization and mundialization have multiple meanings, which does not diminish the importance of understanding them scientifically. It is clear that the phenomenon of mundialization requires the recognition

  2. Global regulation of international intellectual property through Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS: The European Union and Brazil

    Directory of Open Access Journals (Sweden)

    Delphine Aurélie Laurence Defossez

    2017-10-01

    Full Text Available Purpose – This paper focuses on the regulation of copyrights at international level by comparing the situation under the TRIPS agreement in Brazil and in the European Union. Methodology/approach/design – This article analyses standards and literature on regulation, as well as the role of TRIPS agreement. Attention was specially drawn to the market failure theory for justifying regulation, advocated by Baldwin & Cave. The TRIPS agreement will be analysed through Baldwin’s five criteria for good regulation. Findings – The TRIPS agreement substantially widened the scope of governance of copyrights but imposes the WTO view on the matter. Notwithstanding its flaws, the TRIPS agreement remains the most comprehensive international agreement on intellectual property. According to Baldwin’s theory, the TRIPS agreement as a regulation is a good regulation. Indeed, it achieves the major part of the goals it set. However, some of the declared goals have never come to existence and had been replaced by other goals. On the overall, the TRIPS agreement has the capacity to regulate international intellectual property. Originality/value – This paper analyses the TRIPS agreement as a way forward in the harmonization of the rules on intellectual property.

  3. Global power production scenarios to 2100 and the dual role of forests: accelerated climate damage or regulating and provisioning ecosystem services?

    DEFF Research Database (Denmark)

    Callesen, Ingeborg

    The worlds' electrical power production is depending on the current energy infrastructure, and future investments in new power supply facilities using renewable and non-renewable energy sources. Continued growth in power production in the 21st century will cause global environmental change (GEC......). GEC with climate change as an important driver will affect the environment and the economy in multiple ways that can be summarized as losses of biodiversity and changing ecosystem services (ES), but with very diverse temporal and spatial impacts. In a simple global growth model for power production...... on bioelectricity from forest biomass and the associated environmental impacts are outlined using LCA unit process data. The power production is used as a simplified proxy for the global energy supply. It is assumed that the most suitable land under each scenario is reserved for food production, and that changes...

  4. Global MEF2 target gene analysis in cardiac and skeletal muscle reveals novel regulation of DUSP6 by p38MAPK-MEF2 signaling

    Science.gov (United States)

    Wales, Stephanie; Hashemi, Sara; Blais, Alexandre; McDermott, John C.

    2014-01-01

    MEF2 plays a profound role in the regulation of transcription in cardiac and skeletal muscle lineages. To define the overlapping and unique MEF2A genomic targets, we utilized ChIP-exo analysis of cardiomyocytes and skeletal myoblasts. Of the 2783 and 1648 MEF2A binding peaks in skeletal myoblasts and cardiomyocytes, respectively, 294 common binding sites were identified. Genomic targets were compared to differentially expressed genes in RNA-seq analysis of MEF2A depleted myogenic cells, revealing two prominent genetic networks. Genes largely associated with muscle development were down-regulated by loss of MEF2A while up-regulated genes reveal a previously unrecognized function of MEF2A in suppressing growth/proliferative genes. Several up-regulated (Tprg, Mctp2, Kitl, Prrx1, Dusp6) and down-regulated (Atp1a2, Hspb7, Tmem182, Sorbs2, Lmod3) MEF2A target genes were chosen for further investigation. Interestingly, siRNA targeting of the MEF2A/D heterodimer revealed a somewhat divergent role in the regulation of Dusp6, a MAPK phosphatase, in cardiac and skeletal myogenic lineages. Furthermore, MEF2D functions as a p38MAPK-dependent repressor of Dusp6 in myoblasts. These data illustrate that MEF2 orchestrates both common and non-overlapping programs of signal-dependent gene expression in skeletal and cardiac muscle lineages. PMID:25217591

  5. Desenvolvimento vegetativo de Mentha campestris Schur e produção de mentol em diferentes espaçamentos de plantio e épocas de colheita Vegetative development of Mentha campestris Schur and menthol production in different row spaces and harvest times

    Directory of Open Access Journals (Sweden)

    R. Monteiro

    2011-01-01

    Full Text Available A produção de óleos essenciais nas plantas aromáticas é influenciada por fatores bióticos e abióticos. A demanda por esses produtos tem aumentado, sendo os óleos essenciais do gênero Mentha de grande interesse nas indústrias farmacêutica, de cosméticos, alimentícia e agrícola, principalmente em função do composto mentol. Esse trabalho teve como objetivo avaliar o efeito de três espaçamentos de plantio (0,60 x 0,15 m; 0,60 x 0,30 m e 0,60 x 0,45 m e duas épocas de colheita (60 e 90 dias após o plantio na espécie Mentha campestris Schur. O experimento foi conduzido no Centro de Estações Experimentais do Canguiri-UFPR, em Pinhais-PR, no período de janeiro a abril de 2008. O delineamento utilizado foi o de blocos ao acaso em esquema de parcelas subdivididas. Houve diferença significativa para todas as variáveis analisadas. As massas secas de folhas, ramos e total foram maiores que na primeira época. Para a biomassa seca de folhas foram observados maiores valores no menor espaçamento de plantio. O rendimento de óleo essencial foi maior na segunda época de colheita e nos espaçamentos maiores. A produtividade do óleo também foi maior na segunda época de colheita, porém no espaçamento mais adensado. Pode-se concluir como recomendação para M. campestris Schur o espaçamento 0,60 x 0,15 m e colheita aos 90 dias, por terem atingido maior biomassa, rendimento de óleo essencial e produtividade de mentol por hectare.Essential oil production in aromatic plants is influenced by biotic and abiotic factors. The demand for these products has increased, and essential oils from the genus Mentha have been of great interest for pharmaceutical, cosmetic, food and agronomic industries, especially because of the compound menthol. This study aimed to evaluate the effect of three row spaces (0.60 x 0.15 m; 0.60 x 0.30 m and 0.60 x 0.45 m and two harvest times (60 and 90 days after planting on the species Mentha campestris Schur. The

  6. Salicylic acid mediated by the oxidative burst is a key molecule in local and systemic responses of cotton challenged by an avirulent race of Xanthomonas campestris pv malvacearum.

    Science.gov (United States)

    Martinez, C; Baccou, J C; Bresson, E; Baissac, Y; Daniel, J F; Jalloul, A; Montillet, J L; Geiger, J P; Assigbetsé, K; Nicole, M

    2000-03-01

    We analyzed the production of reactive oxygen species, the accumulation of salicylic acid (SA), and peroxidase activity during the incompatible interaction between cotyledons of the cotton (Gossypium hirsutum) cv Reba B50/Xanthomonas campestris pv malvacearum (Xcm) race 18. SA was detected in petioles of cotyledons 6 h after infection and 24 h post inoculation in cotyledons and untreated leaves. The first peak of SA occurred 3 h after generation of superoxide (O(2)(.-)), and was inhibited by infiltration of catalase. Peroxidase activity and accumulation of SA increased in petioles of cotyledons and leaves following H(2)O(2) infiltration of cotyledons from 0.85 to 1 mM. Infiltration of 2 mM SA increased peroxidase activity in treated cotyledons and in the first leaves, but most of the infiltrated SA was rapidly conjugated within the cotyledons. When increasing concentrations of SA were infiltrated 2. 5 h post inoculation at the beginning of the oxidative burst, the activity of the apoplastic cationic O(2)(.-)-generating peroxidase decreased in a dose-dependent manner. We have shown that during the cotton hypersensitive response to Xcm, H(2)O(2) is required for local and systemic accumulation of SA, which may locally control the generation of O(2)(.-). Detaching cotyledons at intervals after inoculation demonstrated that the signal leading to systemic accumulation of SA was emitted around 3 h post inoculation, and was associated with the oxidative burst. SA produced 6 h post infection at HR sites was not the primary mobile signal diffusing systemically from infected cotyledons.

  7. Real time expression of ACC oxidase and PR-protein genes mediated by Methylobacterium spp. in tomato plants challenged with Xanthomonas campestris pv. vesicatoria.

    Science.gov (United States)

    Yim, W J; Kim, K Y; Lee, Y W; Sundaram, S P; Lee, Y; Sa, T M

    2014-07-15

    Biotic stress like pathogenic infection increases ethylene biosynthesis in plants and ethylene inhibitors are known to alleviate the severity of plant disease incidence. This study aimed to reduce the bacterial spot disease incidence in tomato plants caused by Xanthomonas campestris pv. vesicatoria (XCV) by modulating stress ethylene with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of Methylobacterium strains. Under greenhouse condition, Methylobacterium strains inoculated and pathogen challenged tomato plants had low ethylene emission compared to pathogen infected ones. ACC accumulation and ACC oxidase (ACO) activity with ACO related gene expression increased in XCV infected tomato plants over Methylobacterium strains inoculated plants. Among the Methylobacterium spp., CBMB12 resulted lowest ACO related gene expression (1.46 Normalized Fold Expression), whereas CBMB20 had high gene expression (3.42 Normalized Fold Expression) in pathogen challenged tomato. But a significant increase in ACO gene expression (7.09 Normalized Fold Expression) was observed in the bacterial pathogen infected plants. In contrast, Methylobacterium strains enhanced β-1,3-glucanase and phenylalanine ammonia-lyase (PAL) enzyme activities in pathogen challenged tomato plants. The respective increase in β-1,3-glucanase related gene expressions due to CBMB12, CBMB15, and CBMB20 strains were 66.3, 25.5 and 10.4% higher over pathogen infected plants. Similarly, PAL gene expression was high with 0.67 and 0.30 Normalized Fold Expression, in pathogen challenged tomato plants inoculated with CBMB12 and CBMB15 strains. The results suggest that ethylene is a crucial factor in bacterial spot disease incidence and that methylobacteria with ACC deaminase activity can reduce the disease severity with ultimate pathogenesis-related protein increase in tomato. Copyright © 2014 Elsevier GmbH. All rights reserved.

  8. Xanthomonas campestris pv. musacearum: a major constraint to banana, plantain and enset production in central and east Africa over the past decade.

    Science.gov (United States)

    Nakato, Valentine; Mahuku, George; Coutinho, Teresa

    2018-03-01

    Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Xanthomonadales; Family Xanthomonadaceae; Genus Xanthomonas; currently classified as X. campestris pv. musacearum (Xcm). However, fatty acid methyl ester analysis and genetic and genomic evidence suggest that this pathogen is X. vasicola and resides in a separate pathovar. Xcm can be isolated on yeast extract peptone glucose agar (YPGA), cellobiose cephalexin agar and yeast extract tryptone sucrose agar (YTSA) complemented with 5-fluorouracil, cephalexin and cycloheximide to confer semi-selectivity. Xcm can also be identified using direct antigen coating enzyme-linked immunosorbent assay (DAC-ELISA), species-specific polymerase chain reaction (PCR) using GspDm primers and lateral flow devices that detect latent infections. Causes Xanthomonas wilt on plants belonging to the Musaceae, primarily banana (Musa acuminata), plantain (M. acuminata × balbisiana) and enset (Ensete ventricosum). There is a high level of genetic homogeneity within Xcm, although genome sequencing has revealed two major sublineages. Yellowing and wilting of leaves, premature fruit ripening and dry rot, bacterial exudate from cut stems. Xcm has only been found in African countries, namely Burundi, Ethiopia, Democratic Republic of the Congo, Kenya, Rwanda, Tanzania and Uganda. Xcm is transmitted by insects, bats, birds and farming implements. Long-distance dispersal of the pathogen is by the transportation of latently infected plants into new areas. The management of Xcm has relied on cultural practices that keep the pathogen population at tolerable levels. Biotechnology programmes have been successful in producing resistant banana plants. However, the deployment of such genetic material has not as yet been achieved in farmers' fields, and the sustainability of transgenic resistance remains to be addressed. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  9. Identification of novel and conserved miRNAs involved in pollen development in Brassica campestris ssp. chinensis by high-throughput sequencing and degradome analysis

    Science.gov (United States)

    2014-01-01

    Background microRNAs (miRNAs) are endogenous, noncoding, small RNAs that have essential regulatory functions in plant growth, development, and stress response processes. However, limited information is available about their functions in sexual reproduction of flowering plants. Pollen development is an important process in the life cycle of a flowering plant and is a major factor that affects the yield and quality of crop seeds. Results This study aims to identify miRNAs involved in pollen development. Two independent small RNA libraries were constructed from the flower buds of the male sterile line (Bcajh97-01A) and male fertile line (Bcajh97-01B) of Brassica campestris ssp. chinensis. The libraries were subjected to high-throughput sequencing by using the Illumina Solexa system. Eight novel miRNAs on the other arm of known pre-miRNAs, 54 new conserved miRNAs, and 8 novel miRNA members were identified. Twenty-five pairs of novel miRNA/miRNA* were found. Among all the identified miRNAs, 18 differentially expressed miRNAs with over two-fold change between flower buds of male sterile line (Bcajh97-01A) and male fertile line (Bcajh97-01B) were identified. qRT-PCR analysis revealed that most of the differentially expressed miRNAs were preferentially expressed in flower buds of the male fertile line (Bcajh97-01B). Degradome analysis showed that a total of 15 genes were predicted to be the targets of seven miRNAs. Conclusions Our findings provide an overview of potential miRNAs involved in pollen development and interactions between miRNAs and their corresponding targets, which may provide important clues on the function of miRNAs in pollen development. PMID:24559317

  10. Transgenic expression of the rice Xa21 pattern-recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum.

    Science.gov (United States)

    Tripathi, Jaindra N; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

    2014-08-01

    Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, biocontrol agents or resistant cultivars available to control BXW. Here, we take advantage of the robust resistance conferred by the rice pattern-recognition receptor (PRR), XA21, to the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). We identified a set of genes required for activation of Xa21-mediated immunity (rax) that were conserved in both Xoo and Xcm. Based on the conservation, we hypothesized that intergeneric transfer of Xa21 would confer resistance to Xcm. We evaluated 25 transgenic lines of the banana cultivar 'Gonja manjaya' (AAB) using a rapid bioassay and 12 transgenic lines in the glasshouse for resistance against Xcm. About 50% of the transgenic lines showed complete resistance to Xcm in both assays. In contrast, all of the nontransgenic control plants showed severe symptoms that progressed to complete wilting. These results indicate that the constitutive expression of the rice Xa21 gene in banana results in enhanced resistance against Xcm. Furthermore, this work demonstrates the feasibility of PRR gene transfer between monocotyledonous species and provides a valuable new tool for controlling the BXW pandemic of banana, a staple food for 100 million people in east Africa. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  11. Variant histone H2A.Z is globally localized to the promoters of inactive yeast genes and regulates nucleosome positioning.

    Directory of Open Access Journals (Sweden)

    Benoît Guillemette

    2005-12-01

    Full Text Available H2A.Z is an evolutionary conserved histone variant involved in transcriptional regulation, antisilencing, silencing, and genome stability. The mechanism(s by which H2A.Z regulates these various biological functions remains poorly defined, in part due to the lack of knowledge regarding its physical location along chromosomes and the bearing it has in regulating chromatin structure. Here we mapped H2A.Z across the yeast genome at an approximately 300-bp resolution, using chromatin immunoprecipitation combined with tiling microarrays. We have identified 4,862 small regions--typically one or two nucleosomes wide--decorated with H2A.Z. Those "Z loci" are predominantly found within specific nucleosomes in the promoter of inactive genes all across the genome. Furthermore, we have shown that H2A.Z can regulate nucleosome positioning at the GAL1 promoter. Within HZAD domains, the regions where H2A.Z shows an antisilencing function, H2A.Z is localized in a wider pattern, suggesting that the variant histone regulates a silencing and transcriptional activation via different mechanisms. Our data suggest that the incorporation of H2A.Z into specific promoter-bound nucleosomes configures chromatin structure to poise genes for transcriptional activation. The relevance of these findings to higher eukaryotes is discussed.

  12. El tratamiento jurídico de las migraciones internacionales a través de las regulaciones globalistas de gestión de mano de obra (The Legal Treatment of International Migrations Through Globalized Labour Management Regulation

    Directory of Open Access Journals (Sweden)

    Iker Barbero González

    2011-05-01

    Full Text Available This article deals with the emerging global tendency to regulate international migrations, not by regarding a universal humanitarian and labour Law, but according to neoliberal normative production standards: flexibility, informality, governance… Supranational institutions such as the WTO, the IOM or the EU are establishing normative agreements (GATS, the NAFTA, the EEC… that regulate migrations as labour and in profit of the global markets. The new contractual models become fragmented titles that recognize rights as immigrant workers and not as a persons or human beings, placing in a legal limbo those who migrate outside the established mechanisms and that not meet the qualification requirements of the global workforce. This text is addressed to the analysis of the categorization of migrants as disposable labour in the global management of the flows.Este texto está dedicado al análisis de la categorización del migrante como mera “mano de obra” en la gestión global de los flujos. Existe una tendencia global a regular las migraciones, no desde un Derecho formal universal, sino desde lo que podría ser denominado en sentido amplio “Soft Law”. Así, las distintas normas que, a nivel mundial, se encargan de ordenar las migraciones son creadas de acuerdo a los criterios de producción jurídica característicos de la etapa contemporánea de globalización neoliberal: flexibilidad, informalidad, descentralización, gobernanza, etc. Instituciones supranacionales como la OIM, la OMC o la Unión Europea (con la intervención de los Estados nación o sin ella establecen estándares normativos (el AGCS o GATS, el TLCNA, la Blue Card, etc, mediante los cuales se regulan los flujos de migrantes atendiendo a las necesidades del mercado mundial. Los nuevos modelos contractuales se convierten en títulos fragmentados reconocedores de derechos en tanto que trabajador inmigrante y no como persona o ser humano, situando de esta manera, en un penoso

  13. Global profiling of phytohormone dynamics during combined drought and pathogen stress in Arabidopsis thaliana reveals ABA and JA as major regulators

    OpenAIRE

    Gupta, Aarti; Hisano, Hiroshi; Hojo, Yuko; Matsuura, Takakazu; Ikeda, Yoko; Mori, Izumi C.; Senthil-Kumar, Muthappa

    2017-01-01

    Global transcriptome studies demonstrated the existence of unique plant responses under combined stress which are otherwise not seen during individual stresses. In order to combat combined stress plants use signaling pathways and ?cross talk? mediated by hormones involved in stress and growth related processes. However, interactions among hormones? pathways in combined stressed plants are not yet known. Here we studied dynamics of different hormones under individual and combined drought and p...

  14. Comparative transcriptome and proteome analysis reveals a global impact of the nitrogen regulators AreA and AreB on secondary metabolism in Fusarium fujikuroi.

    Directory of Open Access Journals (Sweden)

    Andreas Pfannmüller

    Full Text Available The biosynthesis of multiple secondary metabolites in the phytopathogenic ascomycete Fusarium fujikuroi is strongly affected by nitrogen availability. Here, we present the first genome-wide transcriptome and proteome analysis that compared the wild type and deletion mutants of the two major nitrogen regulators AreA and AreB. We show that AreB acts not simply as an antagonist of AreA counteracting the expression of AreA target genes as suggested based on the yeast model. Both GATA transcription factors affect a large and diverse set of common as well as specific target genes and proteins, acting as activators and repressors. We demonstrate that AreA and AreB are not only involved in fungal nitrogen metabolism, but also in the control of several complex cellular processes like carbon metabolism, transport and secondary metabolism. We show that both GATA transcription factors can be considered as master regulators of secondary metabolism as they affect the expression of more than half of the 47 putative secondary metabolite clusters identified in the genome of F. fujikuroi. While AreA acts as a positive regulator of many clusters under nitrogen-limiting conditions, AreB is able to activate and repress gene clusters (e.g. bikaverin under nitrogen limitation and sufficiency. In addition, ChIP analyses revealed that loss of AreA or AreB causes histone modifications at some of the regulated gene clusters.

  15. BcMF26a and BcMF26b Are Duplicated Polygalacturonase Genes with Divergent Expression Patterns and Functions in Pollen Development and Pollen Tube Formation in Brassica campestris.

    Directory of Open Access Journals (Sweden)

    Meiling Lyu

    Full Text Available Polygalacturonase (PG is one of the cell wall hydrolytic enzymes involving in pectin degradation. A comparison of two highly conserved duplicated PG genes, namely, Brassica campestris Male Fertility 26a (BcMF26a and BcMF26b, revealed the different features of their expression patterns and functions. We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication. Although structurally similar, their regulatory and intron sequences largely diverged. QRT-PCR analysis showed that the expression level of BcMF26b was higher than that of BcMF26a in almost all the tested organs and tissues in Brassica campestris. Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils. In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall. When the two genes were co-inhibited, pollen intine was formed abnormally and pollen tubes could not grow or stretch. Moreover, the knockout mutants of At4g33440 delayed the growth of pollen tubes. Therefore, BcMF26a/b can participate in the construction of pollen wall by modulating intine information and BcMF26b may play a major role in co-inhibiting transformed plants.

  16. Insights from the cold transcriptome and metabolome of Dendrobium officinale: global reprogramming of metabolic and gene regulation networks during cold acclimation

    Directory of Open Access Journals (Sweden)

    Zhi-Gang Wu

    2016-11-01

    Full Text Available Plant cold acclimation (CA is a genetically complex phenomenon involving gene regulation and expression. Little is known about the cascading pattern of gene regulatroy network and the link between genes and metabolites during CA. Dendrobium officinale (DOKM is an important medicinal and ornamental plant and hypersensitive to low temperature. Here, we used the large scale metabolomic and transcriptomic technologies to reveal the response to CA in DOKM seedlings based on the physiological profile analyses. Lowering temperature from 4 oC to -2 oC resulted in significant increase(P<0.01)in antioxidant activities and electrolyte leakage during 24 h. The fitness CA piont of 0 oC and control (20 oC during 20 h were firstly obtained according to physiological analyses. Subsequently, massive transcriptome and metabolome reprogramming occurred during CA. The gene to metabolite network demonstrated that the CA associated processes are highly energy demanding through activating hydrolysis of sugars, amino acids catabolism and citrate cycle. The expression levels of 2,767 genes were significantly affected by CA, including 153-fold upregulation of CBF transcription factor, 56-fold upregulation of MAPKKK16 protein kinase. Moreover, the gene interaction and regulation network analysis revealed that the CA as an active process, was regulated at the transcriptional, post-transcriptional, translational and post-translational levels. Our findings highligted a comprehensive regulatory mechanism including cold signal transduction, transcriptional regulation and gene expression, which contributes a deeper understanding of the highly complex regulatory program during CA in DOKM. Some marker genes identified in DOKM seedlings will allow us to understand the role of each individual during CA by further functional analyses.

  17. Against Globalization

    DEFF Research Database (Denmark)

    Philipsen, Lotte; Baggesgaard, Mads Anders

    2013-01-01

    In order to understand globalization, we need to consider what globalization is not. That is, in order to understand the mechanisms and elements that work toward globalization, we must, in a sense, read against globalization, highlighting the limitations of the concept and its inherent conflicts...

  18. MarA, SoxS and Rob of Escherichia coli – Global regulators of multidrug resistance, virulence and stress response

    Science.gov (United States)

    Duval, Valérie; Lister, Ida M.

    2014-01-01

    Bacteria have a great capacity for adjusting their metabolism in response to environmental changes by linking extracellular stimuli to the regulation of genes by transcription factors. By working in a co-operative manner, transcription factors provide a rapid response to external threats, allowing the bacteria to survive. This review will focus on transcription factors MarA, SoxS and Rob in Escherichia coli, three members of the AraC family of proteins. These homologous proteins exemplify the ability to respond to multiple threats such as oxidative stress, drugs and toxic compounds, acidic pH, and host antimicrobial peptides. MarA, SoxS and Rob recognize similar DNA sequences in the promoter region of more than 40 regulatory target genes. As their regulons overlap, a finely tuned adaptive response allows E. coli to survive in the presence of different assaults in a co-ordinated manner. These regulators are well conserved amongst Enterobacteriaceae and due to their broad involvement in bacterial adaptation in the host, have recently been explored as targets to develop new anti-virulence agents. The regulators are also being examined for their roles in novel technologies such as biofuel production. PMID:24860636

  19. Co-regulation of Iron Metabolism and Virulence Associated Functions by Iron and XibR, a Novel Iron Binding Transcription Factor, in the Plant Pathogen Xanthomonas.

    Science.gov (United States)

    Pandey, Sheo Shankar; Patnana, Pradeep Kumar; Lomada, Santosh Kumar; Tomar, Archana; Chatterjee, Subhadeep

    2016-11-01

    Abilities of bacterial pathogens to adapt to the iron limitation present in hosts is critical to their virulence. Bacterial pathogens have evolved diverse strategies to coordinately regulate iron metabolism and virulence associated functions to maintain iron homeostasis in response to changing iron availability in the environment. In many bacteria the ferric uptake regulator (Fur) functions as transcription factor that utilize ferrous form of iron as cofactor to regulate transcription of iron metabolism and many cellular functions. However, mechanisms of fine-tuning and coordinated regulation of virulence associated function beyond iron and Fur-Fe2+ remain undefined. In this study, we show that a novel transcriptional regulator XibR (named Xanthomonas iron binding regulator) of the NtrC family, is required for fine-tuning and co-coordinately regulating the expression of several iron regulated genes and virulence associated functions in phytopathogen Xanthomonas campestris pv. campestris (Xcc). Genome wide expression analysis of iron-starvation stimulon and XibR regulon, GUS assays, genetic and functional studies of xibR mutant revealed that XibR positively regulates functions involved in iron storage and uptake, chemotaxis, motility and negatively regulates siderophore production, in response to iron. Furthermore, chromatin immunoprecipitation followed by quantitative real-time PCR indicated that iron promoted binding of the XibR to the upstream regulatory sequence of operon's involved in chemotaxis and motility. Circular dichroism spectroscopy showed that purified XibR bound ferric form of iron. Electrophoretic mobility shift assay revealed that iron positively affected the binding of XibR to the upstream regulatory sequences of the target virulence genes, an effect that was reversed by ferric iron chelator deferoxamine. Taken together, these data revealed that how XibR coordinately regulates virulence associated and iron metabolism functions in Xanthomonads in

  20. Effect of Global Regulators RpoS and Cyclic-AMP/CRP on the Catabolome and Transcriptome of Escherichia coli K12 during Carbon- and Energy-Limited Growth.

    Directory of Open Access Journals (Sweden)

    Alessandro G Franchini

    Full Text Available For heterotrophic microbes, limited availability of carbon and energy sources is one of the major nutritional factors restricting the rate of growth in most ecosystems. Physiological adaptation to this hunger state requires metabolic versatility which usually involves expression of a wide range of different catabolic pathways and of high-affinity carbon transporters; together, this allows for simultaneous utilization of mixtures of carbonaceous compounds at low concentrations. In Escherichia coli the stationary phase sigma factor RpoS and the signal molecule cAMP are the major players in the regulation of transcription under such conditions; however, their interaction is still not fully understood. Therefore, during growth of E. coli in carbon-limited chemostat culture at different dilution rates, the transcriptomes, expression of periplasmic proteins and catabolomes of strains lacking one of these global regulators, either rpoS or adenylate cyclase (cya, were compared to those of the wild-type strain. The inability to synthesize cAMP exerted a strong negative influence on the expression of alternative carbon source uptake and degradation systems. In contrast, absence of RpoS increased the transcription of genes belonging to high-affinity uptake systems and central metabolism, presumably due to reduced competition of σ(D with σ(S. Phenotypical analysis confirmed this observation: The ability to respire alternative carbon substrates and to express periplasmic high-affinity binding proteins was eliminated in cya and crp mutants, while these properties were not affected in the rpoS mutant. As expected, transcription of numerous stress defence genes was negatively affected by the rpoS knock-out mutation. Interestingly, several genes of the RpoS stress response regulon were also down-regulated in the cAMP-negative strain indicating a coordinated global regulation. The results demonstrate that cAMP is crucial for catabolic flexibility during slow

  1. Crystal Structures of Xanthomonas campestris OleA Reveal Features That Promote Head-to-Head Condensation of Two Long-Chain Fatty Acids

    Energy Technology Data Exchange (ETDEWEB)

    Goblirsch, Brandon R.; Frias, Janice A.; Wackett, Lawrence P.; Wilmot, Carrie M. (UMM)

    2012-10-25

    OleA is a thiolase superfamily enzyme that has been shown to catalyze the condensation of two long-chain fatty acyl-coenzyme A (CoA) substrates. The enzyme is part of a larger gene cluster responsible for generating long-chain olefin products, a potential biofuel precursor. In thiolase superfamily enzymes, catalysis is achieved via a ping-pong mechanism. The first substrate forms a covalent intermediate with an active site cysteine that is followed by reaction with the second substrate. For OleA, this conjugation proceeds by a nondecarboxylative Claisen condensation. The OleA from Xanthomonas campestris has been crystallized and its structure determined, along with inhibitor-bound and xenon-derivatized structures, to improve our understanding of substrate positioning in the context of enzyme turnover. OleA is the first characterized thiolase superfamily member that has two long-chain alkyl substrates that need to be bound simultaneously and therefore uniquely requires an additional alkyl binding channel. The location of the fatty acid biosynthesis inhibitor, cerulenin, that possesses an alkyl chain length in the range of known OleA substrates, in conjunction with a single xenon binding site, leads to the putative assignment of this novel alkyl binding channel. Structural overlays between the OleA homologues, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase and the fatty acid biosynthesis enzyme FabH, allow assignment of the two remaining channels: one for the thioester-containing pantetheinate arm and the second for the alkyl group of one substrate. A short {beta}-hairpin region is ordered in only one of the crystal forms, and that may suggest open and closed states relevant for substrate binding. Cys143 is the conserved catalytic cysteine within the superfamily, and the site of alkylation by cerulenin. The alkylated structure suggests that a glutamic acid residue (Glu117{beta}) likely promotes Claisen condensation by acting as the catalytic base. Unexpectedly

  2. Crystal Structures of Xanthomonas campestris OleA Reveal Features That Promote Head-to-Head Condensation of Two Long-Chain Fatty Acids

    Energy Technology Data Exchange (ETDEWEB)

    Goblirsch, BR; Frias, JA; Wackett, LP; Wilmot, CM

    2012-05-22

    OleA is a thiolase superfamily enzyme that has been shown to catalyze the condensation of two long-chain fatty acylcoenzyme A (CoA) substrates. The enzyme is part of a larger gene cluster responsible for generating long-chain olefin products, a potential biofuel precursor. In thiolase superfamily enzymes, catalysis is achieved via a ping-pong mechanism. The first substrate forms a covalent intermediate with an active site cysteine that is followed by reaction with the second substrate. For OleA, this conjugation proceeds by a nondecarboxylative Claisen condensation. The OleA from Xanthomonas campestris has been crystallized and its structure determined, along with inhibitor-bound and xenon-derivatized structures, to improve our understanding of substrate positioning in the context of enzyme turnover. OleA is the first characterized thiolase superfamily member that has two long-chain alkyl substrates that need to be bound simultaneously and therefore uniquely requires an additional alkyl binding channel. The location of the fatty acid biosynthesis inhibitor, cerulenin, that possesses an alkyl chain length in the range of known OleA substrates, in conjunction with a single xenon binding site, leads to the putative assignment of this novel alkyl binding channel. Structural overlays between the OleA homologues, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase and the fatty acid biosynthesis enzyme FabH, allow assignment of the two remaining channels: one for the thioester-containing pantetheinate arm and the second for the alkyl group of one substrate. A short beta-hairpin region is ordered in only one of the crystal forms, and that may suggest open and closed states relevant for substrate binding. Cys143 is the conserved catalytic cysteine within the superfamily, and the site of alkylation by cerulenin. The alkylated structure suggests that a glutamic acid residue (Glu117 beta) likely promotes Claisen condensation by acting as the catalytic base. Unexpectedly, Glu117

  3. Potencial alelopático de Brassica campestris subsp. rapa y Lolium temulentum sobre la germinación de semillas de tomate

    Directory of Open Access Journals (Sweden)

    Carolina Zamorano

    2005-07-01

    Full Text Available Con el objeto de evaluar el potencial alelopático de los extractos de hojas de nabo (Brassica campestris subsp. rapa y raigrás (Lolium temulentum, utilizando dos solventes (agua y metanol, se desarrollaron bioensayos con semillas pregerminadas de tomate en el laboratorio de Malherbología de la Universidad Nacional de Colombia, sede Bogotá. Los bioensayos tuvieron un diseño de bloques al azar con tres repeticiones y se replicaron tres veces. Las concentraciones de los extractos utilizados fueron 10, 25, 50 y 100 g. L-1. Como variables se midieron: el porcentaje de germinación, la longitud del brote aéreo y raíz y, adicionalmente, se calculó el porcentaje de elongación con respecto al control. No hubo efectos de los extractos sobre la germinación de semillas de tomate. Los extractos acuosos de nabo tuvieron efectos estimulantes sobre la elongación de la raíz del tomate, con concentraciones de 10 g. L-1, y detrimentales en el rango de 25 a 100 g. L-1; la concentración que redujo el crecimiento en 50% (DC50 estuvo entre 44 y 49 g. L-1, para la longitud de raíz y de brote aéreo, respectivamente. Los extractos metanólicos de nabo disminuyeron la elongación de la raíz de tomate a medida que aumentaba la concentración del extracto. El efecto de los extractos de raigrás sobre la elongación de la raíz del tomate fue similar con los dos solventes, disminuyéndola 40% en promedio con las concentraciones de 10 a 100 g. L-1; la DC50 se calculó para el porcentaje de elongación de la raíz con extracto acuoso y fue 10 g. L-1.

  4. Potencial alelopático de Brassica campestris subsp. rapa y Lolium temulentum sobre tres especies de malezas de la Sabana de Bogotá

    Directory of Open Access Journals (Sweden)

    Carolina Zamorano

    2005-07-01

    Full Text Available Se realizaron bioensayos con el objeto de evaluar el potencial alelopático de los extractos de hojas y residuos de nabo silvestre (Brassica campestris subsp. rapa [L.] Hook. f. y raigrás (Lolium temulentum L. sobre tres especies de malezas de la Sabana de Bogotá: cenizo (Chenopodium petiolare Kunth, malva blanca (Fuertesimalva limensis [L.] Fryxell y bledo (Amaranthus hybridus L.. Los bioensayos en el laboratorio se desarrollaron con la técnica de plántulas en solución nutritiva, bajo un diseño completamente al azar con tres repeticiones y tres réplicas en el tiempo, y en invernadero, donde se usó mezcla de arena y turba (3:2 como sustrato y semillas pregerminadas. Los resultados obtenidos en laboratorio mostraron diferencias en los síntomas observados entre las diferentes especies, mientras que la variable peso fresco fue la que mejor describió el efecto de las concentración para los extractos de nabo, con una concentración que reduce la variable de respuesta en 50% (DC50 de 5,53 g· L-1 para bledo, 2,58 g· L-1 para cenizo y 7,72 g· L-1 para malva blanca. En el caso de raigrás, el peso fresco permitió el ajuste de una curva concentración-respuesta, con el fin de calcular la DC50. La respuesta entre las especies de malezas fue diferente respecto a la actividad de los extractos y de los residuos vegetales en suelo. En el caso del bledo, no se registraron diferencias entre los residuos en suelo y los extractos de nabo, mientras que con cenizo y malva blanca no hubo emergencia de plántulas bajo la condición de residuos en suelo de nabo. El peso fresco de plántulas de tomate disminuyó en cerca del 25% al crecer en residuos de nabo (6 ó 12 t· ha-1 de materia fresca y en cerca del 60% bajo residuos de raigrás (6 t· ha-1 de materia fresca.

  5. The global regulator Ncb2 escapes from the core promoter and impacts transcription in response to drug stress in Candida albicans

    OpenAIRE

    Mohd Shariq; Sanjiveeni Dhamgaye; Remya Nair; Neha Goyal; Vaibhav Jain; Arnab Mukhopadhyay; Mondal, Alok K.; Gauranga Mukhopadhyay; Rajendra Prasad

    2017-01-01

    Ncb2, the ? subunit of NC2 complex, a heterodimeric regulator of transcription was earlier shown to be involved in the activated transcription of CDR1 gene in azole resistant isolate (AR) of Candida albicans. This study examines its genome-wide role by profiling Ncb2 occupancy between genetically matched pair of azole sensitive (AS) and AR clinical isolates. A comparison of Ncb2 recruitment between the two isolates displayed that 29 genes had higher promoter occupancy of Ncb2 in the AR isolat...

  6. Global Strategy

    DEFF Research Database (Denmark)

    Li, Peter Ping

    2013-01-01

    Global strategy differs from domestic strategy in terms of content and process as well as context and structure. The content of global strategy can contain five key elements, while the process of global strategy can have six major stages. These are expounded below. Global strategy is influenced...... by rich and complementary local contexts with diverse resource pools and game rules at the national level to form a broad ecosystem at the global level. Further, global strategy dictates the interaction or balance between different entry strategies at the levels of internal and external networks....

  7. Whole genome transcriptomics reveals global effects including up-regulation of Francisella pathogenicity island gene expression during active stringent response in the highly virulent Francisella tularensis subsp. tularensis SCHU S4.

    Science.gov (United States)

    Murch, Amber L; Skipp, Paul J; Roach, Peter L; Oyston, Petra C F

    2017-11-01

    During conditions of nutrient limitation bacteria undergo a series of global gene expression changes to survive conditions of amino acid and fatty acid starvation. Rapid reallocation of cellular resources is brought about by gene expression changes coordinated by the signalling nucleotides' guanosine tetraphosphate or pentaphosphate, collectively termed (p)ppGpp and is known as the stringent response. The stringent response has been implicated in bacterial virulence, with elevated (p)ppGpp levels being associated with increased virulence gene expression. This has been observed in the highly pathogenic Francisella tularensis sub spp. tularensis SCHU S4, the causative agent of tularaemia. Here, we aimed to artificially induce the stringent response by culturing F. tularensis in the presence of the amino acid analogue l-serine hydroxamate. Serine hydroxamate competitively inhibits tRNAser aminoacylation, causing an accumulation of uncharged tRNA. The uncharged tRNA enters the A site on the translating bacterial ribosome and causes ribosome stalling, in turn stimulating the production of (p)ppGpp and activation of the stringent response. Using the essential virulence gene iglC, which is encoded on the Francisella pathogenicity island (FPI) as a marker of active stringent response, we optimized the culture conditions required for the investigation of virulence gene expression under conditions of nutrient limitation. We subsequently used whole genome RNA-seq to show how F. tularensis alters gene expression on a global scale during active stringent response. Key findings included up-regulation of genes involved in virulence, stress responses and metabolism, and down-regulation of genes involved in metabolite transport and cell division. F. tularensis is a highly virulent intracellular pathogen capable of causing debilitating or fatal disease at extremely low infectious doses. However, virulence mechanisms are still poorly understood. The stringent response is widely

  8. The RNA-Binding Chaperone Hfq Is an Important Global Regulator of Gene Expression in Pasteurella multocida and Plays a Crucial Role in Production of a Number of Virulence Factors, Including Hyaluronic Acid Capsule.

    Science.gov (United States)

    Mégroz, Marianne; Kleifeld, Oded; Wright, Amy; Powell, David; Harrison, Paul; Adler, Ben; Harper, Marina; Boyce, John D

    2016-05-01

    The Gram-negative bacterium Pasteurella multocida is the causative agent of a number of economically important animal diseases, including avian fowl cholera. Numerous P. multocida virulence factors have been identified, including capsule, lipopolysaccharide (LPS), and filamentous hemagglutinin, but little is known about how the expression of these virulence factors is regulated. Hfq is an RNA-binding protein that facilitates riboregulation via interaction with small noncoding RNA (sRNA) molecules and their mRNA targets. Here, we show that a P. multocida hfq mutant produces significantly less hyaluronic acid capsule during all growth phases and displays reduced in vivo fitness. Transcriptional and proteomic analyses of the hfq mutant during mid-exponential-phase growth revealed altered transcript levels for 128 genes and altered protein levels for 78 proteins. Further proteomic analyses of the hfq mutant during the early exponential growth phase identified 106 proteins that were produced at altered levels. Both the transcript and protein levels for genes/proteins involved in capsule biosynthesis were reduced in the hfq mutant, as were the levels of the filamentous hemagglutinin protein PfhB2 and its secretion partner LspB2. In contrast, there were increased expression levels of three LPS biosynthesis genes, encoding proteins involved in phosphocholine and phosphoethanolamine addition to LPS, suggesting that these genes are negatively regulated by Hfq-dependent mechanisms. Taken together, these data provide the first evidence that Hfq plays a crucial role in regulating the global expression of P. multocida genes, including the regulation of key P. multocida virulence factors, capsule, LPS, and filamentous hemagglutinin. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  9. THE GLOBAL TAX [R]EVOLUTION

    National Research Council Canada - National Science Library

    Nazrien Kader

    2015-01-01

    .... The new equilibrium in the global tax environment has resulted in actions on the part of policy-makers, regulators, revenue authorities and taxpayers that can be best described as the "Global Tax (r...

  10. Globalization & technology

    DEFF Research Database (Denmark)

    Narula, Rajneesh

    Technology and globalization are interdependent processes. Globalization has a fundamental influence on the creation and diffusion of technology, which, in turn, affects the interdependence of firms and locations. This volume examines the international aspect of this interdependence at two levels...

  11. PEMANASAN GLOBAL

    Directory of Open Access Journals (Sweden)

    Vivi Triana

    2008-03-01

    Full Text Available Pemanasan global (global warming pada dasarnya merupakan fenomena peningkatan temperature global dari tahun ke tahun karena terjadinya efek rumah kaca (greenhouse effect yang disebabkan oleh meningkatnya emisi gas-gas seperti karbondioksida (CO2, metana (CH4, dinitrooksida (N2O dan CFC sehingga energy matahari terperangkap dalam atmosfer bumi. Berbagai literatur menunjukkan kenaikan temperatur global termasuk Indonesia yang terjadi pada kisaran 1,5 – 40 °C pada akhir abad 21.

  12. Global usability

    CERN Document Server

    Douglas, Ian

    2011-01-01

    The concept of usability has become an increasingly important consideration in the design of all kinds of technology. As more products are aimed at global markets and developed through internationally distributed teams, usability design needs to be addressed in global terms. Interest in usability as a design issue and specialist area of research and education has developed steadily in North America and Europe since the 1980's. However, it is only over the last ten years that it has emerged as a global concern. Global Usability provides an introduction to the important issues in globalizing des

  13. Gene-age interactions in blood pressure regulation: a large-scale investigation with the CHARGE, Global BPgen, and ICBP Consortia.

    Science.gov (United States)

    Simino, Jeannette; Shi, Gang; Bis, Joshua C; Chasman, Daniel I; Ehret, Georg B; Gu, Xiangjun; Guo, Xiuqing; Hwang, Shih-Jen; Sijbrands, Eric; Smith, Albert V; Verwoert, Germaine C; Bragg-Gresham, Jennifer L; Cadby, Gemma; Chen, Peng; Cheng, Ching-Yu; Corre, Tanguy; de Boer, Rudolf A; Goel, Anuj; Johnson, Toby; Khor, Chiea-Chuen; Lluís-Ganella, Carla; Luan, Jian'an; Lyytikäinen, Leo-Pekka; Nolte, Ilja M; Sim, Xueling; Sõber, Siim; van der Most, Peter J; Verweij, Niek; Zhao, Jing Hua; Amin, Najaf; Boerwinkle, Eric; Bouchard, Claude; Dehghan, Abbas; Eiriksdottir, Gudny; Elosua, Roberto; Franco, Oscar H; Gieger, Christian; Harris, Tamara B; Hercberg, Serge; Hofman, Albert; James, Alan L; Johnson, Andrew D; Kähönen, Mika; Khaw, Kay-Tee; Kutalik, Zoltan; Larson, Martin G; Launer, Lenore J; Li, Guo; Liu, Jianjun; Liu, Kiang; Morrison, Alanna C; Navis, Gerjan; Ong, Rick Twee-Hee; Papanicolau, George J; Penninx, Brenda W; Psaty, Bruce M; Raffel, Leslie J; Raitakari, Olli T; Rice, Kenneth; Rivadeneira, Fernando; Rose, Lynda M; Sanna, Serena; Scott, Robert A; Siscovick, David S; Stolk, Ronald P; Uitterlinden, Andre G; Vaidya, Dhananjay; van der Klauw, Melanie M; Vasan, Ramachandran S; Vithana, Eranga Nishanthie; Völker, Uwe; Völzke, Henry; Watkins, Hugh; Young, Terri L; Aung, Tin; Bochud, Murielle; Farrall, Martin; Hartman, Catharina A; Laan, Maris; Lakatta, Edward G; Lehtimäki, Terho; Loos, Ruth J F; Lucas, Gavin; Meneton, Pierre; Palmer, Lyle J; Rettig, Rainer; Snieder, Harold; Tai, E Shyong; Teo, Yik-Ying; van der Harst, Pim; Wareham, Nicholas J; Wijmenga, Cisca; Wong, Tien Yin; Fornage, Myriam; Gudnason, Vilmundur; Levy, Daniel; Palmas, Walter; Ridker, Paul M; Rotter, Jerome I; van Duijn, Cornelia M; Witteman, Jacqueline C M; Chakravarti, Aravinda; Rao, Dabeeru C

    2014-07-03

    Although age-dependent effects on blood pressure (BP) have been reported, they have not been systematically investigated in large-scale genome-wide association studies (GWASs). We leveraged the infrastructure of three well-established consortia (CHARGE, GBPgen, and ICBP) and a nonstandard approach (age stratification and metaregression) to conduct a genome-wide search of common variants with age-dependent effects on systolic (SBP), diastolic (DBP), mean arterial (MAP), and pulse (PP) pressure. In a two-staged design using 99,241 individuals of European ancestry, we identified 20 genome-wide significant (p ≤ 5 × 10(-8)) loci by using joint tests of the SNP main effect and SNP-age interaction. Nine of the significant loci demonstrated nominal evidence of age-dependent effects on BP by tests of the interactions alone. Index SNPs in the EHBP1L1 (DBP and MAP), CASZ1 (SBP and MAP), and GOSR2 (PP) loci exhibited the largest age interactions, with opposite directions of effect in the young versus the old. The changes in the genetic effects over time were small but nonnegligible (up to 1.58 mm Hg over 60 years). The EHBP1L1 locus was discovered through gene-age interactions only in whites but had DBP main effects replicated (p = 8.3 × 10(-4)) in 8,682 Asians from Singapore, indicating potential interethnic heterogeneity. A secondary analysis revealed 22 loci with evidence of age-specific effects (e.g., only in 20 to 29-year-olds). Age can be used to select samples with larger genetic effect sizes and more homogenous phenotypes, which may increase statistical power. Age-dependent effects identified through novel statistical approaches can provide insight into the biology and temporal regulation underlying BP associations. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  14. Animal welfare in a global perspective

    NARCIS (Netherlands)

    Bracke, M.B.M.

    2009-01-01

    Global survey of animal-welfare regulations, practices and perceptions, with case studies on poultry meat from Brazil and Thailand, eggs from India and the USA, welfare regulations of farmed fish and welfare aspects related to (perceived) overpopulation of wildlife

  15. The Global Redox Responding RegB/RegA Signal Transduction System Regulates the Genes Involved in Ferrous Iron and Inorganic Sulfur Compound Oxidation of the Acidophilic Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Danielle Moinier

    2017-07-01

    Full Text Available The chemical attack of ore by ferric iron and/or sulfuric acid releases valuable metals. The products of these reactions are recycled by iron and sulfur oxidizing microorganisms. These acidophilic chemolithotrophic prokaryotes, among which Acidithiobacillus ferrooxidans, grow at the expense of the energy released from the oxidation of ferrous iron and/or inorganic sulfur compounds (ISCs. In At. ferrooxidans, it has been shown that the expression of the genes encoding the proteins involved in these respiratory pathways is dependent on the electron donor and that the genes involved in iron oxidation are expressed before those responsible for ISCs oxidation when both iron and sulfur are present. Since the redox potential increases during iron oxidation but remains stable during sulfur oxidation, we have put forward the hypothesis that the global redox responding two components system RegB/RegA is involved in this regulation. To understand the mechanism of this system and its role in the regulation of the aerobic respiratory pathways in At. ferrooxidans, the binding of different forms of RegA (DNA binding domain, wild-type, unphosphorylated and phosphorylated-like forms of RegA on the regulatory region of different genes/operons involved in ferrous iron and ISC oxidation has been analyzed. We have shown that the four RegA forms are able to bind specifically the upstream region of these genes. Interestingly, the phosphorylation of RegA did not change its affinity for its cognate DNA. The transcriptional start site of these genes/operons has been determined. In most cases, the RegA binding site(s was (were located upstream from the −35 (or −24 box suggesting that RegA does not interfere with the RNA polymerase binding. Based on the results presented in this report, the role of the RegB/RegA system in the regulation of the ferrous iron and ISC oxidation pathways in At. ferrooxidans is discussed.

  16. The Global Redox Responding RegB/RegA Signal Transduction System Regulates the Genes Involved in Ferrous Iron and Inorganic Sulfur Compound Oxidation of the Acidophilic Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Moinier, Danielle; Byrne, Deborah; Amouric, Agnès; Bonnefoy, Violaine

    2017-01-01

    The chemical attack of ore by ferric iron and/or sulfuric acid releases valuable metals. The products of these reactions are recycled by iron and sulfur oxidizing microorganisms. These acidophilic chemolithotrophic prokaryotes, among which Acidithiobacillus ferrooxidans, grow at the expense of the energy released from the oxidation of ferrous iron and/or inorganic sulfur compounds (ISCs). In At. ferrooxidans, it has been shown that the expression of the genes encoding the proteins involved in these respiratory pathways is dependent on the electron donor and that the genes involved in iron oxidation are expressed before those responsible for ISCs oxidation when both iron and sulfur are present. Since the redox potential increases during iron oxidation but remains stable during sulfur oxidation, we have put forward the hypothesis that the global redox responding two components system RegB/RegA is involved in this regulation. To understand the mechanism of this system and its role in the regulation of the aerobic respiratory pathways in At. ferrooxidans, the binding of different forms of RegA (DNA binding domain, wild-type, unphosphorylated and phosphorylated-like forms of RegA) on the regulatory region of different genes/operons involved in ferrous iron and ISC oxidation has been analyzed. We have shown that the four RegA forms are able to bind specifically the upstream region of these genes. Interestingly, the phosphorylation of RegA did not change its affinity for its cognate DNA. The transcriptional start site of these genes/operons has been determined. In most cases, the RegA binding site(s) was (were) located upstream from the -35 (or -24) box suggesting that RegA does not interfere with the RNA polymerase binding. Based on the results presented in this report, the role of the RegB/RegA system in the regulation of the ferrous iron and ISC oxidation pathways in At. ferrooxidans is discussed.

  17. The Global Redox Responding RegB/RegA Signal Transduction System Regulates the Genes Involved in Ferrous Iron and Inorganic Sulfur Compound Oxidation of the Acidophilic Acidithiobacillus ferrooxidans

    Science.gov (United States)

    Moinier, Danielle; Byrne, Deborah; Amouric, Agnès; Bonnefoy, Violaine

    2017-01-01

    The chemical attack of ore by ferric iron and/or sulfuric acid releases valuable metals. The products of these reactions are recycled by iron and sulfur oxidizing microorganisms. These acidophilic chemolithotrophic prokaryotes, among which Acidithiobacillus ferrooxidans, grow at the expense of the energy released from the oxidation of ferrous iron and/or inorganic sulfur compounds (ISCs). In At. ferrooxidans, it has been shown that the expression of the genes encoding the proteins involved in these respiratory pathways is dependent on the electron donor and that the genes involved in iron oxidation are expressed before those responsible for ISCs oxidation when both iron and sulfur are present. Since the redox potential increases during iron oxidation but remains stable during sulfur oxidation, we have put forward the hypothesis that the global redox responding two components system RegB/RegA is involved in this regulation. To understand the mechanism of this system and its role in the regulation of the aerobic respiratory pathways in At. ferrooxidans, the binding of different forms of RegA (DNA binding domain, wild-type, unphosphorylated and phosphorylated-like forms of RegA) on the regulatory region of different genes/operons involved in ferrous iron and ISC oxidation has been analyzed. We have shown that the four RegA forms are able to bind specifically the upstream region of these genes. Interestingly, the phosphorylation of RegA did not change its affinity for its cognate DNA. The transcriptional start site of these genes/operons has been determined. In most cases, the RegA binding site(s) was (were) located upstream from the −35 (or −24) box suggesting that RegA does not interfere with the RNA polymerase binding. Based on the results presented in this report, the role of the RegB/RegA system in the regulation of the ferrous iron and ISC oxidation pathways in At. ferrooxidans is discussed. PMID:28747899

  18. Global analysis of estrogen receptor beta binding to breast cancer cell genome reveals an extensive interplay with estrogen receptor alpha for target gene regulation.

    Science.gov (United States)

    Grober, Oli M V; Mutarelli, Margherita; Giurato, Giorgio; Ravo, Maria; Cicatiello, Luigi; De Filippo, Maria Rosaria; Ferraro, Lorenzo; Nassa, Giovanni; Papa, Maria Francesca; Paris, Ornella; Tarallo, Roberta; Luo, Shujun; Schroth, Gary P; Benes, Vladimir; Weisz, Alessandro

    2011-01-14

    Estrogen receptors alpha (ERα) and beta (ERβ) are transcription factors (TFs) that mediate estrogen signaling and define the hormone-responsive phenotype of breast cancer (BC). The two receptors can be found co-expressed and play specific, often opposite, roles, with ERβ being able to modulate the effects of ERα on gene transcription and cell proliferation. ERβ is frequently lost in BC, where its presence generally correlates with a better prognosis of the disease. The identification of the genomic targets of ERβ in hormone-responsive BC cells is thus a critical step to elucidate the roles of this receptor in estrogen signaling and tumor cell biology. Expression of full-length ERβ in hormone-responsive, ERα-positive MCF-7 cells resulted in a marked reduction in cell proliferation in response to estrogen and marked effects on the cell transcriptome. By ChIP-Seq we identified 9702 ERβ and 6024 ERα binding sites in estrogen-stimulated cells, comprising sites occupied by either ERβ, ERα or both ER subtypes. A search for TF binding matrices revealed that the majority of the binding sites identified comprise one or more Estrogen Response Element and the remaining show binding matrixes for other TFs known to mediate ER interaction with chromatin by tethering, including AP2, E2F and SP1. Of 921 genes differentially regulated by estrogen in ERβ+ vs ERβ- cells, 424 showed one or more ERβ site within 10 kb. These putative primary ERβ target genes control cell proliferation, death, differentiation, motility and adhesion, signal transduction and transcription, key cellular processes that might explain the biological and clinical phenotype of tumors expressing this ER subtype. ERβ binding in close proximity of several miRNA genes and in the mitochondrial genome, suggests the possible involvement of this receptor in small non-coding RNA biogenesis and mitochondrial genome functions. Results indicate that the vast majority of the genomic targets of ERβ can bind

  19. Global analysis of estrogen receptor beta binding to breast cancer cell genome reveals an extensive interplay with estrogen receptor alpha for target gene regulation

    Directory of Open Access Journals (Sweden)

    Papa Maria

    2011-01-01

    Full Text Available Abstract Background Estrogen receptors alpha (ERα and beta (ERβ are transcription factors (TFs that mediate estrogen signaling and define the hormone-responsive phenotype of breast cancer (BC. The two receptors can be found co-expressed and play specific, often opposite, roles, with ERβ being able to modulate the effects of ERα on gene transcription and cell proliferation. ERβ is frequently lost in BC, where its presence generally correlates with a better prognosis of the disease. The identification of the genomic targets of ERβ in hormone-responsive BC cells is thus a critical step to elucidate the roles of this receptor in estrogen signaling and tumor cell biology. Results Expression of full-length ERβ in hormone-responsive, ERα-positive MCF-7 cells resulted in a marked reduction in cell proliferation in response to estrogen and marked effects on the cell transcriptome. By ChIP-Seq we identified 9702 ERβ and 6024 ERα binding sites in estrogen-stimulated cells, comprising sites occupied by either ERβ, ERα or both ER subtypes. A search for TF binding matrices revealed that the majority of the binding sites identified comprise one or more Estrogen Response Element and the remaining show binding matrixes for other TFs known to mediate ER interaction with chromatin by tethering, including AP2, E2F and SP1. Of 921 genes differentially regulated by estrogen in ERβ+ vs ERβ- cells, 424 showed one or more ERβ site within 10 kb. These putative primary ERβ target genes control cell proliferation, death, differentiation, motility and adhesion, signal transduction and transcription, key cellular processes that might explain the biological and clinical phenotype of tumors expressing this ER subtype. ERβ binding in close proximity of several miRNA genes and in the mitochondrial genome, suggests the possible involvement of this receptor in small non-coding RNA biogenesis and mitochondrial genome functions. Conclusions Results indicate that the

  20. Global Mindset

    DEFF Research Database (Denmark)

    Sørensen, Olav Jull

    2016-01-01

    way of thinking about the global business reality. The other extreme is a GM as an organizational capability and process with a GM in a continuous state of becoming – and thus in a continuously alignment with a dynamic context. In addition, we argue for what we call “situational capabilities”, i......The concept of Global Mindset (GM) – the way to think about the global reality – is on the agenda of multinational companies concomitant with the increase in global complexity, uncertainty and diversity. In spite of a number of studies, the concept is still fluid and far from a managerial...

  1. Salutogenesis, globalization, and communication.

    Science.gov (United States)

    Petzold, Theodor Dierk; Lehmann, Nadja

    2011-12-01

    Achieving successful communication in transcultural contexts means integrating emotional communication patterns into a global context. Professional, rational communication is characteristic of the cultural dimension, and emotions are characteristic of the direct, interpersonal dimension of human existence. Humans strive to achieve coherence in all dimensions of their lives; this goal is in the end the most essential aspect of psychophysical self-regulation. A major role in integrating emotional needs and cultural features in global coherence is played by the attractor 'global affinity'. The transitions from emotional coherence to cultural coherence, and likewise from cultural coherence to global coherence, can cause considerable insecurity as well as psychological problems, which previously went by the name 'adjustment disorders'. However, instead of pathologizing these processes, we should understand them in a salutogenic sense as challenges important for both individual and collective development. The development of more coherence is regulated by the neuropsychological approach and avoidance system. This system can be consciously fostered by directing our attention to the commonalities of all human beings. Such a global salutogenic orientation furthers both communication and creativity in teamwork. This article introduces a consequent salutogenic and evolutionary systemic view of transcultural communication and demonstrates its effectiveness in a number of case examples.

  2. Global Uddannelse

    DEFF Research Database (Denmark)

    Jensen, Niels Rosendal

    Antologien handler om "demokratiproblemer i den globale sammenhæng" (del I) og "demokratiproblemer i uddannelse og for de offentligt ansatte" (del II), bundet sammen af et mellemstykke, der rækker ud mod begge poler både det globale og det lokale ved at knytte det til forholdet mellem marked...

  3. Developing Globalization

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    2017-01-01

    This chapter is the first qualitative micro case study of one aspect of globalization: personal networks as a concrete outcome of development assistance spending. The empirical findings related in this paper present circumstantial evidence that Japanese foreign aid has contributed to globalization...

  4. Gendering Globalization

    DEFF Research Database (Denmark)

    Siim, Birte

    2009-01-01

    The current global financial situation bluntly and brutally brings home the fact that the global and local are closely connected in times of opportunity as well as crises. The articles in this issue of Asia Insights are about ontra-action between Asia, particularly China, and the Nordic countries...

  5. Global Mindsets

    DEFF Research Database (Denmark)

    Global Mindsets: Exploration and Perspectives seeks to tackle a topic that is relatively new in research and practice, and is considered by many to be critical for firms seeking to conduct global business. It argues that multiple mindsets exist (across and within organizations), that they operate...... in a global context, and that they are dynamic and undergo change and action. Part of the mindset(s) may depend upon place, situation and context where individuals and organizations operate. The book will examine the notion of "mindset" is situational and dynamic, especially in a global setting, why...... it is important for future scholars and managers and how it could be conceptualized. Global Mindsets: Exploration and Perspectives is split into two major sections; the first examines where the literature currently is with respect to the knowledge in the field and what conceptual frameworks guide the thinking...

  6. Regulating the regulators : accountability of Australian regulators

    National Research Council Canada - National Science Library

    Bird, Joanna

    2011-01-01

    Accountability of Australian regulators - Australian Securities and Investments Commission - Australian Prudential Regulation Authority - concept of 'accountability' - mechanisms for accountability...

  7. Global Content in Global Coursebooks

    Directory of Open Access Journals (Sweden)

    Mimoun Melliti

    2013-10-01

    Full Text Available This study aims at exploring the issue of “globality” in global coursebooks as manifested in investing features of connectedness, avoiding inappropriacy, and preserving inclusivity. To do this exploration, two research methods, content analysis and the questionnaire, were adopted. The content of an example of global coursebooks, Headway Intermediate (H/I, in addition to the perception of 251 of its users at Institute Bourguiba for Living Languages (IBLV were investigated. The results obtained revealed that “globality,” in terms of connectedness, inappropriacy, and inclusivity is partial in H/I as learners’ perceptions of it do not map with the content in the coursebook. This study raises questions about the suitability of global coursebooks to globally diverse learners and reveals the necessity of taking measures in the direction of localizing the content of English as a foreign language (EFL coursebooks.

  8. Going Global

    DEFF Research Database (Denmark)

    Harrington, Brooke

    2015-01-01

    This study links theories of relationality and institutional change to deepen understanding of professionals’ role in globalization. In previous institutional research, it has been conventional to treat professionals as agents of firms or transnational organizations, and institutional change...... environment. It also broadens the model of agency to include invention and improvisation by individual professionals, as a counterpart to collective strategic action. The argument is based on data from a 16-nation study exploring the emergence of a particular ‘globalized localism’: the transformation...... to specify a new, more detailed model of the ways local practices and ideas develop into global institutions....

  9. Global transcription regulation of RK2 plasmids: a case study in the combined use of dynamical mathematical models and statistical inference for integration of experimental data and hypothesis exploration

    Directory of Open Access Journals (Sweden)

    Thomas Christopher M

    2011-07-01

    Full Text Available Abstract Background IncP-1 plasmids are broad host range plasmids that have been found in clinical and environmental bacteria. They often carry genes for antibiotic resistance or catabolic pathways. The archetypal IncP-1 plasmid RK2 is a well-characterized biological system, with a fully sequenced and annotated genome and wide range of experimental measurements. Its central control operon, encoding two global regulators KorA and KorB, is a natural example of a negatively self-regulated operon. To increase our understanding of the regulation of this operon, we have constructed a dynamical mathematical model using Ordinary Differential Equations, and employed a Bayesian inference scheme, Markov Chain Monte Carlo (MCMC using the Metropolis-Hastings algorithm, as a way of integrating experimental measurements and a priori knowledge. We also compared MCMC and Metabolic Control Analysis (MCA as approaches for determining the sensitivity of model parameters. Results We identified two distinct sets of parameter values, with different biological interpretations, that fit and explain the experimental data. This allowed us to highlight the proportion of repressor protein as dimers as a key experimental measurement defining the dynamics of the system. Analysis of joint posterior distributions led to the identification of correlations between parameters for protein synthesis and partial repression by KorA or KorB dimers, indicating the necessary use of joint posteriors for correct parameter estimation. Using MCA, we demonstrated that the system is highly sensitive to the growth rate but insensitive to repressor monomerization rates in their selected value regions; the latter outcome was also confirmed by MCMC. Finally, by examining a series of different model refinements for partial repression by KorA or KorB dimers alone, we showed that a model including partial repression by KorA and KorB was most compatible with existing experimental data. Conclusions We

  10. A global view of regulations affecting nanomaterials

    DEFF Research Database (Denmark)

    Hansen, Steffen Foss

    2010-01-01

    The 2000s have been characterized by an unprecedented exploration into research and development of nanotechnology and nanomaterials. Despite a slow start, new regulatory initiatives are popping up like mushrooms internationally. Many of these initiatives have yet to materialize themselves...

  11. Global Managers

    DEFF Research Database (Denmark)

    Barakat, Livia L.; Lorenz, Melanie P.; Ramsey, Jase R.

    2016-01-01

    . Practical implications: – Results imply that global managers should increase their CQ in order to improve their job satisfaction and ultimately perform better in an international context. Originality/value: – The authors make three primary contributions to the international business literature. First......Purpose: – The purpose of this paper is to examine the effect of cultural intelligence (CQ) on the job performance of global managers. Design/methodology/approach: – In total, 332 global managers were surveyed from multinational companies operating in Brazil. The mediating effect of job...... satisfaction was tested on the CQ-job performance relationship. Findings: – The findings suggest that job satisfaction transmits the effect of CQ to job performance, such that global managers high in CQ exhibit more job satisfaction in an international setting, and therefore perform better at their jobs...

  12. Gendered globalization

    DEFF Research Database (Denmark)

    Milwertz, Cecilia Nathansen; Cai, Yiping

    2017-01-01

    Both the People’s Republic of China (PRC) and Nordic countries (Sweden, Iceland, Denmark, Norway and Finland) view gender equality as a social justice issue and are politically committed towards achieving gender equality nationally and internationally. Since China has taken a proactive position o...... on globalization and global governance, gender equality is possibly an area that China may wish to explore in collaboration with the Nordic countries....

  13. Global warming

    CERN Document Server

    Hulme, M

    1998-01-01

    Global warming-like deforestation, the ozone hole and the loss of species- has become one of the late 20the century icons of global environmental damage. The threat, is not the reality, of such a global climate change has motivated governments. businesses and environmental organisations, to take serious action ot try and achieve serious control of the future climate. This culminated last December in Kyoto in the agreement for legally-binding climate protocol. In this series of three lectures I will provide a perspective on the phenomenon of global warming that accepts the scientific basis for our concern, but one that also recognises the dynamic interaction between climate and society that has always exited The future will be no different. The challenge of global warning is not to pretend it is not happening (as with some pressure groups), nor to pretend it threatens global civilisation (as with other pressure groups), and it is not even a challenge to try and stop it from happening-we are too far down the ro...

  14. Subpolítica Reflexiva no Contexto da Mundialização Informativa aplicada à Regulação Supranacional da Internet / Reflexive Sub-Politics in the context of Globalization of Information and the Internet Supranational Regulation

    Directory of Open Access Journals (Sweden)

    Bruna Pinotti Garcia

    2016-05-01

    , agendas emerge about Internet regulation that are every step less restricted to the traditional regulatory actors, allowing a greater participation of the individual in this process, with the possibility of designing sub-politics in a more simplified concept of globalization. Practical implications – The article provides to the scientific community and the society cognitive foundations necessary for inclusion of social actors in virtual spaces in the field of supranational regulation of new information technologies. Originality/value – The terms globalization and mundialization have multiple meanings, which does not diminish the importance of understanding them scientifically. It is clear that the phenomenon of mundialization requires the recognition that it should not be perceived as something restricted to the states. The relevance of the subject has not been accompanied by sufficient scientific production in the field.

  15. Markets, religion, regulation

    DEFF Research Database (Denmark)

    Fischer, Johan

    2016-01-01

    of regulation, certification and standardization on a global scale. Building on research on global kosher (a Hebrew term meaning “fit” or “proper”), halal (an Arabic word that literally means “permissible” or “lawful”) and Hindu vegetarianism this paper argues that these economies or markets to a large extent...... and consumers. Epistemologically, comparison is used as a powerful conceptual mechanism that fixes attention on kosher, halal and Hindu vegetarian similarities and differences....

  16. Global Derivatives

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    approaches to dealing in the global business environment." - Sharon Brown-Hruska, Commissioner, Commodity Futures Trading Commission, USA. "This comprehensive survey of modern risk management using derivative securities is a fine demonstration of the practical relevance of modern derivatives theory to risk......""In Global Derivatives: A Strategic Risk Management Perspective", Torben Juul Andersen has succeeded to gather in one book a complete and thorough summary and an easy-to-read explanation of all types of derivative instruments and their background, and their use in modern management of risk......." - Steen Parsholt, Chairman and CEO, Aon Nordic Region. "Andersen has done a wonderful job of developing a comprehensive text that deals with risk management in global markets. I would recommend this book to any student or businessman who has a need to better understand the risks and risk management...

  17. Global Inequality

    DEFF Research Database (Denmark)

    Niño-Zarazúa, Miguel; Roope, Laurence; Tarp, Finn

    2017-01-01

    This paper measures trends in global interpersonal inequality during 1975–2010 using data from the most recent version of the World Income Inequality Database (WIID). The picture that emerges using ‘absolute,’ and even ‘centrist’ measures of inequality, is very different from the results obtained...... using standard ‘relative’ inequality measures such as the Gini coefficient or Coefficient of Variation. Relative global inequality has declined substantially over the decades. In contrast, ‘absolute’ inequality, as captured by the Standard Deviation and Absolute Gini, has increased considerably...... and unabated. Like these ‘absolute’ measures, our ‘centrist’ inequality indicators, the Krtscha measure and an intermediate Gini, also register a pronounced increase in global inequality, albeit, in the case of the latter, with a decline during 2005 to 2010. A critical question posed by our findings is whether...

  18. Global overeksponering

    DEFF Research Database (Denmark)

    Rosenstand, Claus A. Foss

    2007-01-01

    ved begyndelsen til en ny global verden, som vi bliver nød til at indrette som sådan, og jeg tror at den nye ungdomskulter er ekstremt sensible overfor de globale strømninger, og vi gør klogt i at tænke over, hvad det er, der egentligt er på færre i stedet for at pege på sagesløse forældre om skyldige....

  19. The Site-Directed A184S Mutation in the HTH Domain of the Global Regulator IrrE Enhances Deinococcus radiodurans R1 Tolerance to UV Radiation and MMC Shock.

    Science.gov (United States)

    Zhang, Chen; Zhou, Zhengfu; Zhang, Wei; Chen, Zhen; Song, Yuan; Lu, Wei; Lin, Min; Chen, Ming

    2015-12-28

    IrrE is a highly conserved global regulator in the Deinococcus genus and contributes to survival from high doses of UV radiation, ionizing radiation, and desiccation. Drad-IrrE and Dgob-IrrE from Deinococcus radiodurans and Deinococcus gobiensis I-0 each share 66% sequence identity. However, Dgob-IrrE showed a stronger protection phenotype against UV radiation than Drad- IrrE in the D. radiodurans irrE-deletion mutant (ΔirrE), which may be due to amino acid residues differences around the DNA-binding HTH domain. Site-directed mutagenesis was used to generate a Drad-IrrE A184S single mutant, which has been characterized and compared with the ΔirrE mutant complemented strain with Drad-irrE, designated ΔirrE-E. The effects of the A184S mutation following UV radiation and mitomycin C (MMC) shock were determined. The A184S mutant displayed significantly increased resistance to UV radiation and MMC shock. The corresponding A184 site in Dgob-IrrE was inversely mutated, generating the S131A mutant, which exhibited a loss of resistance against UV radiation, MMC shock, and desiccation. qPCR analysis revealed that critical genes in the DNA repair system, such as recA, pprA, uvrA, and ddrB, were remarkably induced after UV radiation and MMC shock in the ΔirrE-IE and A184S mutants. These data suggested that A184S improves the ability against UV radiation and MMC shock, providing new insights into the modification of IrrE. We speculated that the serine residue may determine the efficiency of DNA binding, leading to the increased expression of IrrE-dependent genes important for protection against DNA damage.

  20. Globalizing America

    DEFF Research Database (Denmark)

    Brewer, Thomas L.; Boyd, Gavin

    An argument that globalization is an ungoverned integration process in which US firms are agents of structural change. It describes the benefits and costs (for example, generating pressure for protection of US home markets), and reviews the expansion of interdependencies between the US and others....

  1. Global Rome

    DEFF Research Database (Denmark)

    Is 21st-century Rome a global city? Is it part of Europe's core or periphery? This volume examines the “real city” beyond Rome's historical center, exploring the diversity and challenges of life in neighborhoods affected by immigration, neoliberalism, formal urban planning, and grassroots social ...

  2. Global Games

    NARCIS (Netherlands)

    van Bottenburg, Maarten

    2001-01-01

    Why is soccer the sport of choice in South America, while baseball has soared to popularity in the Carribean? How did cricket become India's national sport, while China is a stronghold of table tennis? In Global Games, Maarten van Bottenburg asserts that it is the 'hidden competition' of social and

  3. Production of the Quinone-Methide Triterpene Maytenin by In Vitro Adventitious Roots of Peritassa campestris (Cambess. A.C.Sm. (Celastraceae and Rapid Detection and Identification by APCI-IT-MS/MS

    Directory of Open Access Journals (Sweden)

    Tiago Antunes Paz

    2013-01-01

    Full Text Available Establishment of adventitious root cultures of Peritassa campestris (Celastraceae was achieved from seed cotyledons cultured in semisolid Woody Plant Medium (WPM supplemented with 2% sucrose, 0.01% PVP, and 4.0 mg L−1 IBA. Culture period on accumulation of biomass and quinone-methide triterpene maytenin in adventitious root were investigated. The accumulation of maytenin in these roots was compared with its accumulation in the roots of seedlings grown in a greenhouse (one year old. A rapid detection and identification of maytenin by direct injection into an atmospheric-pressure chemical ionization ion trap tandem mass spectrometer (APCI-IT-MS/MS were performed without prior chromatographic separation. In vitro, the greatest accumulation of biomass occurred within 60 days of culture. The highest level of maytenin—972.11 μg·g−1 dry weight—was detected at seven days of cultivation; this value was 5.55-fold higher than that found in the roots of seedlings grown in a greenhouse.

  4. Production of the quinone-methide triterpene maytenin by in vitro adventitious roots of Peritassa campestris (Cambess.) A.C.Sm. (Celastraceae) and rapid detection and identification by APCI-IT-MS/MS.

    Science.gov (United States)

    Paz, Tiago Antunes; dos Santos, Vânia A F F M; Inácio, Marielle Cascaes; Pina, Edieidia Souza; Pereira, Ana Maria Soares; Furlan, Maysa

    2013-01-01

    Establishment of adventitious root cultures of Peritassa campestris (Celastraceae) was achieved from seed cotyledons cultured in semisolid Woody Plant Medium (WPM) supplemented with 2% sucrose, 0.01% PVP, and 4.0 mg L⁻¹ IBA. Culture period on accumulation of biomass and quinone-methide triterpene maytenin in adventitious root were investigated. The accumulation of maytenin in these roots was compared with its accumulation in the roots of seedlings grown in a greenhouse (one year old). A rapid detection and identification of maytenin by direct injection into an atmospheric-pressure chemical ionization ion trap tandem mass spectrometer (APCI-IT-MS/MS) were performed without prior chromatographic separation. In vitro, the greatest accumulation of biomass occurred within 60 days of culture. The highest level of maytenin--972.11  μ g·g⁻¹ dry weight--was detected at seven days of cultivation; this value was 5.55-fold higher than that found in the roots of seedlings grown in a greenhouse.

  5. Panwapa: Global Kids, Global Connections

    Science.gov (United States)

    Berson, Ilene R.; Berson, Michael J.

    2009-01-01

    Panwapa, created by the Sesame Street Workshop of PBS, is an example of an initiative on the Internet designed to enhance students' learning by exposing them to global communities. Panwapa means "Here on Earth" in Tshiluba, a Bantu language spoken in the Democratic Republic of Congo. At the Panwapa website, www.panwapa.org, children aged…

  6. Governing Global Capital

    DEFF Research Database (Denmark)

    Harrington, Brooke

    How do professions affect the configuration of political economies worldwide? This study addresses the question through interviews with members of a new transnational profession - wealth management - whose innovations are reshaping the balance of power in global finance. Wealth managers specialize...... in helping elites avoid taxes and other forms of regulation. The study documents how the means through which they achieve this objective - shifting billions in private capital wealth between Asia, Africa, India and Europe - and how this affects the balance of regional economic power. Drawing from...... an institutionalist perspective, the paper examines three ways in which wealth managers, both individually and through their professional society, influence regional competition for power and wealth: 1) by finding loopholes in existing policies that limit the global flow of capital; 2) by lobbying national...

  7. On Globalization

    Directory of Open Access Journals (Sweden)

    Charles Hanly

    2010-06-01

    Full Text Available É impressionante como, num curto período de tempo, o site da internet “Facebook” fortaleceu o conceito de McLuhan sobre “aldeia global” com o de “lugar de encontro” e ainda criou as bases potenciais para a existência de uma vizinhança global. Todos os principais avanços em tecnologia da comunicação fizeram do mundo, desde McLuhan, algo muito mais aldeão do que foi antes, mesmo no tempo de McLuhan duas décadas atrás. Mas a globalização é um processo e é preciso compreender sua estrutura e seu dinamismo à maneira dos analistas que procuram, com o intuito de melhorar a vida dos indivíduos, entender a psique humana. Pode, pois, a psicanálise contribuir para a compreensão da aldeia global? Podemos ter a esperança de que a aldeia global formada pelas tecnologias comunicacionais nos pacifiquem e nos unam?

  8. Global safety

    Directory of Open Access Journals (Sweden)

    Dorien J. DeTombe

    2010-08-01

    Full Text Available Global Safety is a container concept referring to various threats such as HIV/Aids, floods and terrorism; threats with different causes and different effects. These dangers threaten people, the global economy and the slity of states. Policy making for this kind of threats often lack an overview of the real causes and the interventions are based on a too shallow analysis of the problem, mono-disciplinary and focus mostly only on the effects. It would be more appropriate to develop policy related to these issues by utilizing the approaches, methods and tools that have been developed for complex societal problems. Handling these complex societal problems should be done multidisciplinary instead of mono-disciplinary. In order to give politicians the opportunity to handle complex problems multidisciplinary, multidisciplinary research institutes should be created. These multidisciplinary research institutes would provide politicians with better approaches to handle this type of problem. In these institutes the knowledge necessary for the change of these problems can be created through the use of the Compram methodology which has been developed specifically for handling complex societal problems. In a six step approach, experts, actors and policymakers discuss the content of the problem and the possible changes. The framework method uses interviewing, the Group Decision Room, simulation models and scenario's in a cooperative way. The methodology emphasizes the exchange of knowledge and understanding by communication among and between the experts, actors and politicians meanwhile keeping emotion in mind. The Compram methodology will be further explained in relation to global safety in regard to terrorism, economy, health care and agriculture.

  9. Conceived globals

    DEFF Research Database (Denmark)

    Cheraghi, Maryam; Schøtt, Thomas

    2016-01-01

    the intending, starting and operating phases, fairly constantly with only small fluctuations. The firm is conceived global in terms of the entrepreneur's transnational networking already in the pre-birth phase, when the entrepreneur is intending to start the firm. These phase effects hardly depend on attributes...... and culture which have separate effects. Being man, young, educated and having entrepreneurial competencies promote transnational networking extensively. Networking is embedded in culture, in the way that transnational networking is more extensive in secular-rational culture than in traditional culture....

  10. The RNA-Binding Chaperone Hfq Is an Important Global Regulator of Gene Expression in Pasteurella multocida and Plays a Crucial Role in Production of a Number of Virulence Factors, Including Hyaluronic Acid Capsule

    National Research Council Canada - National Science Library

    Mégroz, Marianne; Kleifeld, Oded; Wright, Amy; Powell, David; Harrison, Paul; Adler, Ben; Harper, Marina; Boyce, John D

    2016-01-01

    .... multocida virulence factors have been identified, including capsule, lipopolysaccharide (LPS), and filamentous hemagglutinin, but little is known about how the expression of these virulence factors is regulated...

  11. Global health and global health ethics

    National Research Council Canada - National Science Library

    Benatar, S. R; Brock, Gillian

    2011-01-01

    ...? What are our responsibilities and how can we improve global health? Global Health and Global Health Ethics addresses these questions from the perspective of a range of disciplines, including medicine, philosophy and the social sciences...

  12. Globalization and management

    Directory of Open Access Journals (Sweden)

    Danimir Štros

    2014-12-01

    Full Text Available Globalization as an ongoing process allows and promotes the development of economy of big countries as well as developing countries that are seeking their place in the global market. Interactive communication has been enabled between people, companies, civil society organizations and other institutions, whose needs can be met over the internet anywhere in the world and at any time. Also, professional and competent human resources are needed and therefore it is necessary to invest in new knowledge, innovation, new technologies and lifelong learning. In this environment, management sets its strategic goals through which it will be able to carry out the plans for the sale of products or services. Nowadays, a manager has to have interdisciplinary skills and lifelong education because only in this way it is possible to respond to the constant and rapid changes in the world. We are witnesses that Europe has reunited in order to compete with the less developed countries with their products and services. Europe has long refused to accept the managerial style of governance, particularly in public administration and is therefore far behind the U.S., but also the Third World countries. Until recently, European public administration was more focused on the implementation of laws and regulations and less on managerial governance of the U.S. type. Global environment requires the continuous research, monitoring competition, innovation and the ability to change rapidly.

  13. Global Geomorphology

    Science.gov (United States)

    Douglas, I.

    1985-01-01

    Any global view of landforms must include an evaluation of the link between plate tectonics and geomorphology. To explain the broad features of the continents and ocean floors, a basic distinction between the tectogene and cratogene part of the Earth's surface must be made. The tectogene areas are those that are dominated by crustal movements, earthquakes and volcanicity at the present time and are essentially those of the great mountain belts and mid ocean ridges. Cratogene areas comprise the plate interiors, especially the old lands of Gondwanaland and Laurasia. Fundamental as this division between plate margin areas and plate interiors is, it cannot be said to be a simple case of a distinction between tectonically active and stable areas. Indeed, in terms of megageomorphology, former plate margins and tectonic activity up to 600 million years ago have to be considered.

  14. Global gamesmanship.

    Science.gov (United States)

    MacMillan, Ian C; van Putten, Alexander B; McGrath, Rita Gunther

    2003-05-01

    Competition among multinationals these days is likely to be a three-dimensional game of global chess: The moves an organization makes in one market are designed to achieve goals in another in ways that aren't immediately apparent to its rivals. The authors--all management professors-call this approach "competing under strategic interdependence," or CSI. And where this interdependence exists, the complexity of the situation can quickly overwhelm ordinary analysis. Indeed, most business strategists are terrible at anticipating the consequences of interdependent choices, and they're even worse at using interdependency to their advantage. In this article, the authors offer a process for mapping the competitive landscape and anticipating how your company's moves in one market can influence its competitive interactions in others. They outline the six types of CSI campaigns--onslaughts, contests, guerrilla campaigns, feints, gambits, and harvesting--available to any multiproduct or multimarket corporation that wants to compete skillfully. They cite real-world examples such as the U.S. pricing battle Philip Morris waged with R.J. Reynolds--not to gain market share in the domestic cigarette market but to divert R.J. Reynolds's resources and attention from the opportunities Philip Morris was pursuing in Eastern Europe. And, using data they collected from their studies of consumer-products companies Procter & Gamble and Unilever, the authors describe how to create CSI tables and bubble charts that present a graphical look at the competitive landscape and that may uncover previously hidden opportunities. The CSI mapping process isn't just for global corporations, the authors explain. Smaller organizations that compete with a portfolio of products in just one national or regional market may find it just as useful for planning their next business moves.

  15. GLOBALIZATION AND IMPORT RISKS

    Directory of Open Access Journals (Sweden)

    Popa Ioan

    2014-07-01

    Full Text Available Delocalization of production and diversification of the sources of offer in the global market place the issue of protection of consumer rights in major consumption centres, namely the European Union in a new light. A review of policies for the protection of consumer rights in the EU, USA and China, reveals major differences regarding the protection of consumer rights and the existence of gaps, and in particular the implementation of effective legislation in this regard. As such, the risks associated with imports have become a major concern in the European Union. The consumer has – one can say – a central role in the globalization process, which justifies the measures aimed at its protection. Although worldwide there are major differences in the degree of market regulation in matters of protection of consumer rights, the trend is the continuous adaptation of the offer to the requirements of global demand. However, one can still find significant gaps which translate into risks specific to the consumers in developed countries, namely in the EU. An important issue arises from this radical change of the localization of production centres in relation to the main consumption centres. While in the developed world, consumer rights protection has reached high levels both by creating an appropriate legislative framework and through consumer awareness and activism regarding their rights, in areas where much of the offer comes from the Western market (China, India, etc. modern mentality on the protection of consumer rights is just emerging. A major requirement is therefore the provision of a status of the consumer compatible with the benefits and risks of globalization, a status defined by safety and protection of imports. This paper confirms the thesis that, ultimately, the main factor counteracting the risks in matters of protection of consumer rights is the consumer, its awareness of its rights.

  16. The contradictory impact of globalization and migration on gender equality

    DEFF Research Database (Denmark)

    Siim, Birte

    2009-01-01

    Globalization and migration have increased diversities and inequalities within and between nation-states and have created new problems regarding public policies intented to regulate political and socio-economic problems on national and global levels. Globalization and increased migration thus rep...... represent a thoeretical, normative and political challenge to understanding how gender and diversity at the national level are linked to processes of globalization. This article identifies some of the many issues involved in the Asia-Nordic 'local-global dialectic'....

  17. Globalization and deficit and limitations of global governance

    Directory of Open Access Journals (Sweden)

    Stojanović Stanislav

    2016-01-01

    Full Text Available Character and dynamics of relationships in international politics, in which the stronger return to real politics content in the functioning of the foreign policy of the great powers, unequivocally affirms that globalization does not work to its declining power that is less credible design concept of modern world society. The global financial collapse that hit the world in 2008 is a convincing indication that most of the globalization is discredited. The belief in one humanity is becoming a less desirable concept. At the same time, with the increase in global issues that require solving, there are numerous human activities that involve unique or international regulation. The world is increasingly one homeostatic system of interdependent parts of a continent where many aspects of the borders between countries are difficult or even impossible to sustain. Hence the importance of global factors, some of which will fully depend on the articulation of individual and community life of people in the future, stressing the importance of the issue of joint management to ensure global peace and security and promote the prosperity around the world in a universally acceptable and effective way. Therefore, the demonstrated substantial shortcomings of global governance of the world, although they discourage belief in humanity, did not reduce the objective need for global access to many amenities of modern human existence. Many aspects of security, ranging from the security of the individual to the energy and environmental security in modern conditions are not conceivable without international access. However, global security management has been associated with numerous limitations and challenges.

  18. Global ethics: the nature and purpose

    Directory of Open Access Journals (Sweden)

    Ye. M. Sulima

    2017-07-01

    Full Text Available The article discusses the factors of forming, the essence and importance of a global ethic as a moral regulator of intercultural interaction in the modern global society. The current global ethics built around basic common goals - peace and dignity of people, social justice, individual freedom, cultural pluralism, sustainable development - and allow plans to achieve different objectives, functioning set of identities and nationalities. It lies in increasing awareness of common fate, common human and social rights, interests, shared vulnerability to global environmental, social and political crises of necessity, consequent, to find common solutions and act on the basis of cultural dialogue and cooperation.

  19. Global Warming on Triton

    Science.gov (United States)

    Elliot, J. L.; Hammel, H. B.; Wasserman, L. H.; Franz, O. G.; McDonald, S. W.; Person, M. J.; Olkin, C. B.; Dunham, E. J.; Spencer, J. R.; Stansberry, J. A.; hide

    1998-01-01

    Triton, Neptune's largest moon, has been predicted to undergo significant seasonal changes that would reveal themselves as changes in its mean frost temperature. But whether this temperature should at the present time be increasing, decreasing or constant depends on a number of parameters (such as the thermal properties of the surface, and frost migration patterns) that are unknown. Here we report observations of a recent stellar occultation by Triton which, when combined with earlier results, show that Triton has undergone a period of global warming since 1989. Our most conservative estimates of the rate of temperature and surface-pressure increase during this period imply that the atmosphere is doubling in bulk every 10 years, significantly faster than predicted by any published frost model for Triton. Our result suggests that permanent polar caps on Triton play a c dominant role in regulating seasonal atmospheric changes. Similar processes should also be active on Pluto.

  20. The financial crises of globalization

    Directory of Open Access Journals (Sweden)

    Edgar Vieira Posada

    2014-06-01

    Full Text Available In the twentieth century there was a debate between Keynesian and the market neoliberal economy school and the Keyneysian model prevail until the arrival of contemporary globalization,that adopted the neoliberal paradigm. Instead of a productive globalization a financial globalization was first developed which has led to recurring crises since 1929; the last one erupted in 2008 and it is still having a negative impact on the economic environment of the planet. The result has been to produce a very slow market self-regulation of the neoliberal model by introducing again monitoring and follow-up mechanisms by States and international organisms for predicting the occurrence of such serious crises for world economy

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