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Daniel J. Gage - One of the best experts on this subject based on the ideXlab platform.
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Plasmids that insert into the rhamnose utilization locus, rha: a versatile tool for genetic studies in Sinorhizobium meliloti.
Journal of Molecular Microbiology and Biotechnology, 2009Co-Authors: Catalina Arango Pinedo, Daniel J. GageAbstract:Described is a suite of plasmids that can be used to deliver DNA into a specific site in the chromosome of Sinorhizobium meliloti with a minimal impact in the physiology of the orga
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Transcriptional control of a rRNA promoter of the nodulating symbiont Sinorhizobium meliloti
FEMS microbiology letters, 2003Co-Authors: Michelle Rosado, Daniel J. GageAbstract:We constructed a stable, low-copy-number plasmid containing a fusion between a Sinorhizobium meliloti rRNA promoter and gfp(mut3). When transformed into S. meliloti the resulting strain, Rm1021/pKW1, fluoresced in proportion to its growth rate during balanced growth. This strain also showed an unexpected behavior when grown to stationary phase in TY medium: the average cellular fluorescence increased through mid-exponential phase then decreased dramatically. The explanation for this appears to be that transcription from the rRNA promoter was shut off in mid-exponential phase and intracellular Gfp was diluted by continued cell growth.
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analysis of infection thread development using gfp and dsred expressing Sinorhizobium meliloti
Journal of Bacteriology, 2002Co-Authors: Daniel J. GageAbstract:Sinorhizobium meliloti growth inside infection threads was monitored after inoculation of alfalfa with red- or green-tagged bacteria. Most threads were populated with single bacterial types. Mixed infections were present but gave mixed nodules less often than expected. These patterns are explained by a model describing bacterial growth during infection.
Frédérique Barloy-hubler - One of the best experts on this subject based on the ideXlab platform.
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Sequencing the Sinorhizobium meliloti genome.
Dna Sequence, 2009Co-Authors: Francis Galibert, Frédérique Barloy-hubler, Delphine Capela, Jérôme GouzyAbstract:The Sinorhizobium meliloti genome consists of three replicons. This bacterium forms an intricate symbiotic relationship with the roots of certain legumes and is considered as an agriculturally important nitrogen-fixer. A consortium of 6 European laboratories was organized to sequence its single chromosome (3.7 Mb), whereas the other two elements (pSyma 1.4 Mb and pSymb 1.7 Mb) will be sequenced by other groups.
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Characterization and expression patterns of Sinorhizobium meliloti tmRNA (ssrA).
Fems Microbiology Letters, 2007Co-Authors: Vincent M. Ulvé, Angélique Chéron, Annie Trautwetter, Catherine Fontenelle, Frédérique Barloy-hublerAbstract:tmRNA (ssrA) in Sinorhizobium meliloti is a small RNA annotated by homology with the Bradyrhizobium japonicum sra molecule. Here, this molecule is described in Sinorhizobium meliloti as a model for such molecules in Alphaproteobacteria subgroup-2. Northern blot analysis and mapping of both 5' and 3' ends of this tmRNA allow the identification of two pieces: a 214 nt mRNA-like domain and an 82 nt tRNA-like domain, both highly stable, whereas the premature form is unstable. Transcriptional studies reveal that Sinorhizobium meliloti tmRNA is mainly expressed during growth resumption, replication initiation and various stress responses.
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The composite genome of the legume symbiont Sinorhizobium meliloti
Science, 2001Co-Authors: Francis Galibert, P. Abola, M. J. Barnet, F. Ampe, Turlough M Finan, Frédérique Barloy-hubler, S. R. Long, Alfred Puhler, A. Becker, P. BoistardAbstract:The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments.
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Nucleotide sequence and predicted functions of the entire Sinorhizobium meliloti pSymA megaplasmid
Proceedings of the National Academy of Sciences of the United States of America, 2001Co-Authors: M. J. Barnett, Francis Galibert, Frédérique Barloy-hubler, Delphine Capela, R F Fisher, T Jones, C Komp, A P Abola, L Bowser, J GouzyAbstract:The symbiotic nitrogen-fixing soil bacterium Sinorhizobium meliloti contains three replicons: pSymA, pSymB, and the chromosome. We report here the complete 1,354,226-nt sequence of pSymA. In addition to a large fraction of the genes known to be specifically involved in symbiosis, pSymA contains genes likely to be involved in nitrogen and carbon metabolism, transport, stress, and resistance responses, and other functions that give S. meliloti an advantage in its specialized niche.
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High-resolution physical map of the Sinorhizobium meliloti 1021 pSyma megaplasmid.
Journal of Bacteriology, 2000Co-Authors: Frédérique Barloy-hubler, Delphine Capela, Melanie J. Barnett, Sue Kalman, Nancy A. Federspiel, Sharon R. Long, Francis GalibertAbstract:To facilitate sequencing of the Sinorhizobium meliloti 1021 pSyma megaplasmid, a high-resolution map was constructed by ordering 113 overlapping bacterial artificial chromosome clones with 192 markers. The 157 anonymous sequence tagged site markers (81,072 bases) reveal hypothetical functions encoded by the replicon.
Didier Hérouart - One of the best experts on this subject based on the ideXlab platform.
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H2O2 Is Required for Optimal Establishment of the Medicago sativa/Sinorhizobium meliloti Symbiosis
Journal of Bacteriology, 2007Co-Authors: Alexandre Jamet, Karine Mandon, Alain Puppo, Didier HérouartAbstract:The symbiotic interaction between Medicago sativa and Sinorhizobium meliloti RmkatB++ overexpressing the housekeeping catalase katB is delayed, and this delay is combined with an enlargement of infection threads. This result provides evidence that H2O2 is required for optimal progression of infection threads through the root hairs and plant cell layers.
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The katA Catalase Gene Is Regulated by OxyR in both Free-Living and Symbiotic Sinorhizobium meliloti
Journal of bacteriology, 2005Co-Authors: Alexandre Jamet, Alain Puppo, Ernö Kiss, Jacques Batut, Didier HérouartAbstract:The characterization of an oxyR insertion mutant provides evidences that katA, which encodes the unique H2O2-inducible HPII catalase, is regulated by OxyR not only in free-living Sinorhizobium meliloti but also in symbiotic S. meliloti. Moreover, oxyR is expressed independently of exogenous H2O2 and downregulates its own expression in S. meliloti.
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oxidative burst in alfalfa Sinorhizobium meliloti symbiotic interaction
Molecular Plant-microbe Interactions, 2001Co-Authors: Renata Santos, Didier Hérouart, Samuel Sigaud, Daniele Touati, Alain PuppoAbstract:Reactive oxygen species are produced as an early event in plant defense response against avirulent pathogens. We show here that alfalfa responds to infection with Sinorhizobium meliloti by production of superoxide and hydrogen peroxide. This similarity in the early response to infection by pathogenic and symbiotic bacteria addresses the question of which mechanism rhizobia use to counteract the plant defense response.
Francis Galibert - One of the best experts on this subject based on the ideXlab platform.
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Sequencing the Sinorhizobium meliloti genome.
Dna Sequence, 2009Co-Authors: Francis Galibert, Frédérique Barloy-hubler, Delphine Capela, Jérôme GouzyAbstract:The Sinorhizobium meliloti genome consists of three replicons. This bacterium forms an intricate symbiotic relationship with the roots of certain legumes and is considered as an agriculturally important nitrogen-fixer. A consortium of 6 European laboratories was organized to sequence its single chromosome (3.7 Mb), whereas the other two elements (pSyma 1.4 Mb and pSymb 1.7 Mb) will be sequenced by other groups.
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The composite genome of the legume symbiont Sinorhizobium meliloti
Science, 2001Co-Authors: Francis Galibert, P. Abola, M. J. Barnet, F. Ampe, Turlough M Finan, Frédérique Barloy-hubler, S. R. Long, Alfred Puhler, A. Becker, P. BoistardAbstract:The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments.
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Nucleotide sequence and predicted functions of the entire Sinorhizobium meliloti pSymA megaplasmid
Proceedings of the National Academy of Sciences of the United States of America, 2001Co-Authors: M. J. Barnett, Francis Galibert, Frédérique Barloy-hubler, Delphine Capela, R F Fisher, T Jones, C Komp, A P Abola, L Bowser, J GouzyAbstract:The symbiotic nitrogen-fixing soil bacterium Sinorhizobium meliloti contains three replicons: pSymA, pSymB, and the chromosome. We report here the complete 1,354,226-nt sequence of pSymA. In addition to a large fraction of the genes known to be specifically involved in symbiosis, pSymA contains genes likely to be involved in nitrogen and carbon metabolism, transport, stress, and resistance responses, and other functions that give S. meliloti an advantage in its specialized niche.
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High-resolution physical map of the Sinorhizobium meliloti 1021 pSyma megaplasmid.
Journal of Bacteriology, 2000Co-Authors: Frédérique Barloy-hubler, Delphine Capela, Melanie J. Barnett, Sue Kalman, Nancy A. Federspiel, Sharon R. Long, Francis GalibertAbstract:To facilitate sequencing of the Sinorhizobium meliloti 1021 pSyma megaplasmid, a high-resolution map was constructed by ordering 113 overlapping bacterial artificial chromosome clones with 192 markers. The 157 anonymous sequence tagged site markers (81,072 bases) reveal hypothetical functions encoded by the replicon.
Graham C. Walker - One of the best experts on this subject based on the ideXlab platform.
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A Highly Conserved Protein of Unknown Function Is Required by Sinorhizobium meliloti for Symbiosis and Environmental Stress Protection
Journal of bacteriology, 2007Co-Authors: Bryan William Davies, Graham C. WalkerAbstract:We report here the first characterization of the Sinorhizobium meliloti open reading frame SMc01113. The SMc01113 protein is a member of a highly conserved protein family, universal among bacteria. We demonstrate that the SMc01113 gene is absolutely required for S. meliloti symbiosis with alfalfa and also for the protection of the bacterium from a wide range of environmental stresses.
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Identification of novel Sinorhizobium meliloti mutants compromised for oxidative stress protection and symbiosis.
Journal of bacteriology, 2006Co-Authors: Bryan William Davies, Graham C. WalkerAbstract:Employing a novel two-part screen, we identified Sinorhizobium meliloti mutants that were both sensitive to hydrogen peroxide and symbiotically defective on the host plant Medicago sativa. The mutations affect a wide variety of cellular processes and represent both novel and previously identified genes important in symbiosis.
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BacA-Mediated Bleomycin Sensitivity in Sinorhizobium meliloti Is Independent of the Unusual Lipid A Modification
Journal of bacteriology, 2006Co-Authors: Gail P Ferguson, Victoria L Marlow, An Jansen, Graham C. WalkerAbstract:Sinorhizobium meliloti bacA mutants are symbiotically defective, deoxycholate sensitive, and bleomycin resistant. We show that the bleomycin resistance phenotype is independent of the lipid A alteration and that the changes giving rise to both phenotypes are likely to be involved in the inability of bacA mutants to persist within their hosts.