Sinorhizobium meliloti
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA35047 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| Other | ||||
| SRR058927.fastq.gz | Fastqsanger.gz | |||
| SRR058928.fastq.gz | Fastqsanger.gz | |||
| SRR058929.fastq.gz | Fastqsanger.gz | |||
| SRR060180.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:Symbiotic nitrogen fixation (SNF) is an energetically expensive process performed by bacteria known as rhizobia during endosymbiotic relationships with leguminous plants. The bacteria require the plant to provide a carbon source for generation of the reductant to power SNF. Although it is well known that C4-dicarboxylates (succinate, fumarate, malate) function as the primary, if not sole, carbon source provided to the rhizobia, the relative contribution of each C4-dicarboxylate is not known. Here, we employ genetic and systems-level analyses to address this issue. Expression of a malate specific transporter (MaeP) in Sinorhizobium meliloti Rm1021 dct mutants unable to transport C4-dicarboxylates resulted in malate import rates up to ~ 30% that of wild type S. meliloti. This was sufficient to support SNF with Medicago sativa, with acetylene reduction rates up to ~ 50% those of plants inoculated with wild type S. meliloti. Rhizobium leguminosarum bv. viciae 3841 dct mutants unable to transport C4-dicarboxylates but expressing the maeP transporter had strong symbiotic properties, with Pisum sativum plants inoculated with these strains appearing similar to plants inoculated with wild type R. leguminosarum. This was despite malate transport rates by the mutant bacteroids being < 10% those of the wild type. A transcriptomics analysis of the combined plant/bacterium nodule transcriptome was performed using RNA-sequencing to identify any systems-level adaptations in response to the inability of the bacteria to import succinate or fumarate. Few transcriptional changes, with no obvious pattern, were revealed by this analysis. Overall, these data illustrated that succinate and fumarate are not essential for SNF, and that at least in specific symbioses, L-malate is likely to naturally serve as the primary C4-dicarboxylate provided to the bacterium.
2017-09-16 | GSE101430 | GEO
Project description:NfeR1 is a S. meliloti sRNA highly expressed in response to osmostress and during the symbiotic interaction of this bacterium with alfalfa plants. We have probed the NfeR1-dependent transcriptome by competitive hybridization on Sm14kOLIGO microarrays of RNA from the wild-type strain Sm2B3001 and from a mutant derivative lacking NfeR1 upon growth in unmodified minimal medium or after 1 h shock with 400 mM NaCl.
2017-04-19 | E-MTAB-5588 | biostudies-arrayexpress
Project description:Genome Variation in the Symbiotic Nitrogen-Fixing Bacterium Sinorhizobium meliloti
| PRJNA117055 | ENA
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:Malic enzymes decarboxylate the tricarboxylic acid (TCA) cycle intermediate malate to the glycolytic end-product pyruvate and are well positioned to regulate metabolic flux in central carbon metabolism. The bacterium Sinorhizobium meliloti has a NAD(P)-malic enzyme (DME) and a NADP-malic enzyme (TME) and DME is required for symbiotic N2-fixation. To help understand the role of these enzymes, we examined growth, metabolic and transcriptional consequences resulting from the deletion of these enzymes. Few effects were observed upon growth with glucose, whereas growth with the gluconeogenic substrate, succinate, resulted in transcriptional and metabolic effects particularly in the dme mutant strains. When grown with succinate, DME mutant cells accumulated hexose sugar phosphates and trehalose, while TME mutants accumulated putrescine. Succinate-grown DME mutant cells also showed increased transcription of genes for gluconeogenesis and for pathways such as amino acid and fatty acid synthesis that divert metabolites away from the TCA cycle. These data suggested that, DME is required to regulate the levels of TCA cycle intermediates and that the activity of TME is insufficient to prevent the accumulation of TCA cycle intermediates in cells utilizing succinate as carbon source. Consistent with this, in short-1-3 hour incubations with succinate, dme mutant cells excreted large amounts of malate whereas little malate was excreted from tme or wild-type cells. These results support the suggestion that DME is required for N2-fixation in alfalfa because it is required for synthesis of pyruvate and acetyl-CoA and the rapid metabolism of C4-dicarboxylates supplied by the plant.
2015-07-25 | GSE71308 | GEO
Project description:Many bacteria, often associated with eukaryotic hosts and of relevance for biotechnological applications, harbor a multipartite genome composed of more than one replicon. Biotechnologically relevant phenotypes are often encoded by genes residing on the secondary replicons. A synthetic biology approach to developing enhanced strains for biotechnological purposes could therefore involve merging pieces or entire replicons from multiple strains into a single genome. Here we report the creation of a genomic hybrid strain in a model multipartite genome species, the plant-symbiotic bacterium Sinorhizobium meliloti. We term this strain as cis-hybrid, since it is produced by genomic material coming from the same species' pangenome. In particular, we moved the secondary replicon pSymA (accounting for nearly 20% of total genome content) from a donor S. meliloti strain to an acceptor strain. The cis-hybrid strain was screened for a panel of complex phenotypes (carbon/nitrogen utilization phenotypes, intra- and extracellular metabolomes, symbiosis, and various microbiological tests). Additionally, metabolic network reconstruction and constraint-based modeling were employed for in silico prediction of metabolic flux reorganization. Phenotypes of the cis-hybrid strain were in good agreement with those of both parental strains. Interestingly, the symbiotic phenotype showed a marked cultivar-specific improvement with the cis-hybrid strains compared to both parental strains. These results provide a proof-of-principle for the feasibility of genome-wide replicon-based remodelling of bacterial strains for improved biotechnological applications in precision agriculture.
2021-03-17 | MTBLS576 | MetaboLights
Project description:The bacterium, Sinorhizobium meliloti, interacts symbiotically with leguminous plants such as Medicago truncatula to form nitrogen-fixing root nodules. During symbiosis, plant and bacterial cells differentiate in a coordinated manner, resulting in specialized plant cells that contain nitrogen-fixing bacteroids. Medicago nodules are organized in structurally distinct tissue zones, representing different stages of bacterial and plant differentiation. We used laser-capture microdissection (LCM) to analyze bacterial and plant gene expression in four root nodule regions. In parallel, we analyzed gene expression in nodules formed by wild type bacteria on six plant mutants with nitrogen fixation deficiencies (dnf). We found that bacteroid metabolism is drastically remodeled during bacteroid differentiation. Many processes required for bacterial growth are down-regulated in the nitrogen fixation zone. The overall transcriptional changes are similar to those occurring during nutrient limitation by the stringent response. We also observed differential expression of bacterial genes involved in nitrogen fixation, cell envelope homeostasis, cell division, stress response and polyamine biosynthesis at distinct stages of nodule development. In M. truncatula we observed the differential regulation of several host processes that may trigger bacteroid differentiation and control bacterial infection. We analyzed plant and bacterial gene expression simultaneously, which allowed us to correlate processes in both organisms.
2015-06-01 | GSE53705 | GEO
Project description:The RNA-binding protein Hfq is a global regulator, which controls diverse cellular processes in bacteria. To begin understanding the role of Hfq in the Sinorhizobium meliloti-Medicago truncatula nitrogen-fixing symbiosis, we defined free-living and symbiotic phenotypes of an hfq mutant. Over 500 transcripts were differentially accumulated in the hfq mutant of S. meliloti Rm1021 when grown in a shaking culture.
2010-06-01 | GSE19346 | GEO
Project description:Investigation of whole genome gene expression level changes in a Sinorhizobium meliloti 1021 rpoH1 rpoH2 double mutant, compared to the wild-type strain. The mutations engineered into this strain render it deficient in symbiotic nitrogen fixation. The mutants analyzed in this study are further described in Mitsui, H, T. Sato, Y. Sato, and K. Minamisawa. 2004. Sinorhizobium meliloti RpoH1 is required for effective nitrogen-fixing symbiosis with alfalfa. Mol Gen Genomics 271:416-425.
2014-11-01 | GSE62900 | GEO
Project description:Sinorhizobium meliloti establishes symbiotic relationship with compatible leguminous plants by inducing root nodule formation, colonizing such nodules, and fixing molecular nitrogen for the host in exchange for carbon compounds. This mutualistic process requires complex communication and tight regulation to allow yet constrain infection to specific tissues. Production of succinoglycan, or exopolysaccharide-I (EPS-I), enables S. meliloti to invade the root cortex via infection threads. A previous genetic screen identified jspA (SMc03872), encoding an extracytoplasmic protease, as a regulator of EPS-I production. To elucidate its molecular role, we performed transcriptome analyses of strains overexpressing wild-type or mutant alleles of jspA. We observed changes in gene expression suggesting that JspA contributes to symbiosis efficiency by modulating the critical ExoR-ExoS-ChvI signaling pathway.
2023-05-10 | GSE155833 | GEO