Project description:Diversity of endophytic bacteria and nitrogen-fixing bacteria in nodules of Vicia villosa in rocky desertification area of Southwest
Project description:Distribution characteristics of endophytic bacteria and endophytic nitrogen-fixing bacteria in Vicia faba root nodules in rocky desertification areas of Southwest China
| PRJNA1184945 | ENA
Project description:Soil microbial diversity in rocky desertification area of Zhangjiajie
Project description:Alnus glutinosa belongs to a family of angiosperms called actinorhizal plants because they can develop nitrogen-fixing nodules in association with the soil bacteria Frankia. The aim of this transcriptomic study was to get a global view of the plant symbiotic genetic program and to identify new key plant genes that control nodulation during symbiosis in A. glutinosa. Symbiosis between A. glutinosa and Frankia was obtained after inoculation of young plant with a concentrated culture of the bacteria. Inoculation was performed in a medium depleted in nitrogen which favors the induction of nitrogen fixing symbiosis. For this study we considered two stages of symbiosis: - an early stage where inoculated roots were harvested 7 days after inoculation with the bacteria and compared to two controls (non-inoculated roots grown with or without nitrogen and harvested at the same time) - a late stage where nodules (nitrogen-fixing specific organs) were harvested 21 days after inoculation and compared to non-inoculated roots harvested on the day of inoculation (which is our reference time 0d). Three biological replicates were used for each condition.
Project description:Casuarina glauca belongs to a family of angiosperms called actinorhizal plants because they can develop nitrogen-fixing nodules in association with the soil bacteria Frankia. The aim of this transcriptomic study was to get a global view of the plant symbiotic genetic program and to identify new key plant genes that control nodulation during symbiosis in C. glauca. Symbiosis between C. glauca and Frankia was obtained after inoculation of young plant with a concentrated culture of the bacteria. Inoculation was performed in a medium depleted in nitrogen which favors the induction of nitrogen fixing symbiosis. For this study we considered two stages of symbiosis: - an early stage where inoculated roots were harvested 7 days after inoculation with the bacteria and compared to two controls (non-inoculated roots grown with or without nitrogen and harvested at the same time) - a late stage where nodules (nitrogen-fixing specific organs) were harvested 21 days after inoculation and compared to non-inoculated roots harvested on the day of inoculation (which is our reference time 0d). Three biological replicates were used for each condition.
2011-04-07 | GSE24158 | GEO
Project description:Bacterial community in rocky desertification region of Three Gorges Reservoir area
Project description:During the legume-rhizobium symbiosis, free-living soil bacteria known as rhizobia trigger the formation of root nodules. The rhizobia infect these organs and adopt an intracellular lifestyle within the symbiotic nodule cells where they become nitrogen-fixing bacteroids. Several legume lineages enforce their symbionts into an extreme cellular differentiation, comprising cell enlargement and genome endoreduplication. The antimicrobial peptide transporter BclA is a major determinant of this differentiation process in Bradyrhizobium sp. ORS285, a symbiont of Aeschynomene spp.. In the absence of BclA, Bradyrhizobium sp. ORS285 proceeds until the intracellular infection of nodule cells but the bacteria cannot differentiate into enlarged polyploid bacteroids and fix nitrogen. The nodule bacteria of the bclA mutant constitute thus an intermediate stage between the free-living soil bacteria and the intracellular nitrogen-fixing bacteroids. Metabolomics on whole nodules of Aeschynomene afraspera and Aeschynomene indica infected with the ORS285 wild type or the bclA mutant revealed 47 metabolites that differentially accumulated concomitantly with bacteroid differentiation. Bacterial transcriptome analysis of these nodules discriminated nodule-induced genes that are specific to differentiated and nitrogen-fixing bacteroids and others that are activated in the host microenvironment irrespective of bacterial differentiation and nitrogen fixation. These analyses demonstrated that the intracellular settling of the rhizobia in the symbiotic nodule cells is accompanied with a first transcriptome switch involving several hundreds of upregulated and downregulated genes and a second switch accompanying the bacteroid differentiation, involving less genes but that are expressed to extremely elevated levels. The transcriptomes further highlighted the dynamics of oxygen and redox regulation of gene expression during nodule formation and we discovered that bclA represses the expression of non-ribosomal peptide synthetase gene clusters suggesting a non-symbiotic function of BclA. Together, our data uncover the metabolic and gene expression changes that accompany the transition from intracellular bacteria into differentiated nitrogen-fixing bacteroids.
Project description:chemolithoautotrophic bacteria inhabiting three different soil types in typical karst rocky desertification ecosystems in Southwest China Raw sequence reads
Project description:With a view to re-annotate the genome sequence of the nitrogen fixing bacterium Sinorhizobium meliloti, we generated oriented sequences of transcripts. To cover a large number of expressed genes we prepared RNA from bacteria grown in three very different physiological conditions including bacteria grown in liquid cultures (in both exponential and stationary growth phases) and from 10-day-old nodules in which bacteria were differentiated in nitrogen fixing bacteroids. The transcripts sequences were then integrated into EuGene-P, a new prokaryotic genome annotation tool able to integrate high throughput data including oriented RNA-Seq data directly into the prediction process, which led to the production of an accurate and complete annotation of the genome of S. meliloti strain 2011.
Project description:Casuarina glauca belongs to a family of angiosperms called actinorhizal plants because they can develop nitrogen-fixing nodules in association with the soil bacteria Frankia. The aim of this transcriptomic study was to study the role of the plant growth regulator auxin during actinorhizal symbiosis and to identify key plant genes that are involved in auxin signaling during symbiosis in C. glauca. Symbiosis between C. glauca and Frankia was obtained after inoculation of young plant with a concentrated culture of the bacteria. Inoculation was performed in a medium depleted in nitrogen (N2) which favors the induction of nitrogen fixing symbiosis. For auxin role study, plant were treated with 25µM 1-naphtoxy acetic acid (1-NOA) all along nodulation time. Nodule were harvested 3 weeks after inoculation. For this study we considered two stages: - 21 days old nodules obtained on plants not treated with 1-NOA (control condition) - 21 days old nodules obtained on plants supplemented with 25µM of 1-NOA. Three biological replicates were used for each condition, however due to non valid staistics, two of the replicates (one for control condition, one for treated condition were removed.