Cowpea symbiotic nitrogen fixing bacteria
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ABSTRACT:
PROVIDER: PRJEB41090 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Some legume plants can establish a nitrogen-fixing symbiosis with rhizobia. Compatibilty between rhizobia and legumes is determined at species-specific level, but there are variations on the efficiency of the process determined by the capacity of the plant to select specific strains that are better partners in terms of the biological outcome. In this work we used a model system based in the coevolution of two genetic pools of common bean (Phaseolus vulgaris) with strains of R. etli that establish a more efficient interaction to study the transcriptional changes occurring in roots at an early time of the interaction.
2020-12-10 | GSE155568 | GEO
Project description:Differences in genome size and gene content are among the most important signatures of microbial adaptation and genome evolution. Here, we investigated the patterns of genome variation among strains of the symbiotic nitrogen-fixing bacterium Sinorhizobium meliloti. Using the sequenced strain Rm1021 as a reference, the genome size and gene content variations were analyzed among ten diverse natural strains, through pulse field gel electrophoresis (PFGE) and whole-genome microarray hybridizations. Our PFGE analysis showed a genome size range of 6.45-7.01Mbp, with the greatest variation arising from the pSymA replicon, followed by that of pSymB. No observable size difference was evident among the chromosomes. Consistent with this pattern of size differences, 41.2% of ORFs on pSymA were variably absent/present, followed by 12.7% on pSymB, and 3.7% on the chromosome. However, the percentages of ORFs that were variably duplicated were more evenly distributed among the three replicons, 11.0%, 16.5% and 15.3% respectively for ORFs on pSymA, pSymB and the chromosome. Among the 10 strains, the percentages of absent ORFs ranged from 1.51% to 6.35% and those of duplicated ORFs ranged from 0.27% to 8.56%. Our analyses showed that host plants, geographic origins, multilocus enzyme electrophoretic types, and replicon sizes had little influence on the distribution patterns of absent or duplicated ORFs. The proportions of ORFs that were either variably absent/present or variably duplicated differed greatly among the functional categories, for each of the three replicons as well as for the whole genome. Interestingly, we observed positive correlations among the three replicons in their numbers of absent ORFs as well as the numbers of duplicated ORFs, consistent with coordinated gene gains/losses in this important bacterium in nature. microarray:Sm6kOligo
2009-05-01 | GSE15889 | GEO
Project description:The complex symbiotic relationship between corals and their dinoflagellate partner Symbiodinium is believed to be sustained through close associations with mutualistic bacterial communities, though little is known about coral associations with bacterial groups able to fix nitrogen (diazotrophs). In this study, we investigated the diversity of diazotrophic bacterial communities associated with three common coral species (Acropora millepora, Acropora muricata, and Pocillopora damicormis) from three midshelf locations of the Great Barrier Reef (GBR) by profiling the conserved subunit of the nifH gene, which encodes the dinitrogenase iron protein. Comparisons of diazotrophic community diversity among coral tissue and mucus microenvironments and the surrounding seawater revealed that corals harbor diverse nifH phylotypes that differ between tissue and mucus microhabitats. Coral mucus nifH sequences displayed high heterogeneity, and many bacterial groups overlapped with those found in seawater. Moreover, coral mucus diazotrophs were specific neither to coral species nor to reef location, reflecting the ephemeral nature of coral mucus. In contrast, the dominant diazotrophic bacteria in tissue samples differed among coral species, with differences remaining consistent at all three reefs, indicating that coral-diazotroph associations are species specific. Notably, dominant diazotrophs for all coral species were closely related to the bacterial group rhizobia, which represented 71% of the total sequences retrieved from tissue samples. The species specificity of coral-diazotroph associations further supports the coral holobiont model that bacterial groups associated with corals are conserved. Our results suggest that, as in terrestrial plants, rhizobia have developed a mutualistic relationship with corals and may contribute fixed nitrogen to Symbiodinium.
| S-EPMC3346485 | biostudies-literature
Project description:Genes specific to cowpea: cowpea vs adzuki bean
| PRJNA453500 | ENA
Project description:To identify novel microRNAs that are associated with drought tolerance in two different cowpea genotypes, we generated small RNA sequences from adult cowpea plants under control and dought stress treatments. Over 79 million raw reads were generated and numerous novel microRNAs are identified, including some associated with drought tolerance.
2011-09-01 | GSE26402 | GEO
Project description:Cowpea is a legume of great agronomic importance that establishes symbiotic relationships with nitrogen-fixing bacteria. However, little is known about the genetic and symbiotic diversity of these bacteria in distinct ecosystems. Our study evaluated the genetic diversity and symbiotic efficiencies of 119 bacterial strains isolated from agriculture soils in the western Amazon using cowpea as a trap plant. These strains were clustered into 11 cultural groups according to growth rate and pH. The 57 nonnodulating strains were predominantly fast growing and acidifying, indicating a high incidence of endophytic strains in the nodules. The other 62 strains, authenticated as nodulating bacteria, exhibited various symbiotic efficiencies, with 68% of strains promoting a significant increase in shoot dry matter of cowpea compared with the control with no inoculation and low levels of mineral nitrogen. Fifty genotypes with 70% similarity and 21 genotypes with 30% similarity were obtained through repetitive DNA sequence (BOX element)-based PCR (BOX-PCR) clustering. The 16S rRNA gene sequencing of strains representative of BOX-PCR clusters showed a predominance of bacteria from the genus Bradyrhizobium but with high species diversity. Rhizobium, Burkholderia, and Achromobacter species were also identified. These results support observations of cowpea promiscuity and demonstrate the high symbiotic and genetic diversity of rhizobia species in areas under cultivation in the western Amazon.
| S-EPMC3426679 | biostudies-literature
Project description:Differences in genome size and gene content are among the most important signatures of microbial adaptation and genome evolution. Here, we investigated the patterns of genome variation among strains of the symbiotic nitrogen-fixing bacterium Sinorhizobium meliloti. Using the sequenced strain Rm1021 as a reference, the genome size and gene content variations were analyzed among ten diverse natural strains, through pulse field gel electrophoresis (PFGE) and whole-genome microarray hybridizations. Our PFGE analysis showed a genome size range of 6.45-7.01Mbp, with the greatest variation arising from the pSymA replicon, followed by that of pSymB. No observable size difference was evident among the chromosomes. Consistent with this pattern of size differences, 41.2% of ORFs on pSymA were variably absent/present, followed by 12.7% on pSymB, and 3.7% on the chromosome. However, the percentages of ORFs that were variably duplicated were more evenly distributed among the three replicons, 11.0%, 16.5% and 15.3% respectively for ORFs on pSymA, pSymB and the chromosome. Among the 10 strains, the percentages of absent ORFs ranged from 1.51% to 6.35% and those of duplicated ORFs ranged from 0.27% to 8.56%. Our analyses showed that host plants, geographic origins, multilocus enzyme electrophoretic types, and replicon sizes had little influence on the distribution patterns of absent or duplicated ORFs. The proportions of ORFs that were either variably absent/present or variably duplicated differed greatly among the functional categories, for each of the three replicons as well as for the whole genome. Interestingly, we observed positive correlations among the three replicons in their numbers of absent ORFs as well as the numbers of duplicated ORFs, consistent with coordinated gene gains/losses in this important bacterium in nature. microarray:Sm6kOligo A total of 12 strains were included for the microarray analyses in this study. The 12 strains included two reference strains and ten other natural strains. Reference strain Rm1021 was the strain with a completely sequenced genome, from which the whole genome microarray was based on (Krol et al. 2004). The second reference strain RmF909 was derived from strain Rm1021 but with a deletion of 575 ORFs located on the megaplasmid pSymB (genomic location 106724-735431, Charles et al. 1991). The two reference strains were used for positive and negative controls in our microarray hybridization experiments and for establishing threshold values for determining whether an ORF is present or absent among natural strains.
2010-05-19 | E-GEOD-15889 | biostudies-arrayexpress
Project description:To identify novel microRNAs that are associated with drought tolerance in two different cowpea genotypes, we generated small RNA sequences from adult cowpea plants under control and dought stress treatments. Over 79 million raw reads were generated and numerous novel microRNAs are identified, including some associated with drought tolerance. Sequencing of small RNAs in two cowpea genotypes under control and drought stress conditions.
2011-09-01 | E-GEOD-26402 | biostudies-arrayexpress