Comprehensive assessment of the regulons controlled by the FixLJ-FixK2-FixK1 cascade in Bradyrhizobium japonicum
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PROVIDER: PRJNA112969 | ENA |
REPOSITORIES: ENA
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Project description:Genome-wide transcription profiling of B. japonicum fixJ, fixK2, and fixK1 mutant strains which were grown in free-living microoxic condition, and in the case of the fixK1 mutant also in anoxic condition. Transcriptomes of nodules from soybean plants infected with the fixJ or fixK2 mutant strains were investigated, too. This study includes also the expression data of a nifA mutant grown in free-living anoxic condition. Samples from GSM210242 to GSM210286 in GEO record number GSE8478 need to be considered for the analyses. Keywords: gene regulation, genetic modification, growth conditions, symbiosis Comparison analysis of the B. japonicum fixJ, fixK2 and fixK1 mutants and the wild type grown under different oxygen conditions in culture and during symbiosis with soybean.
2010-05-23 | E-GEOD-12491 | biostudies-arrayexpress
Project description:Genome-wide transcription profiling of B. japonicum fixJ, fixK2, and fixK1 mutant strains which were grown in free-living microoxic condition, and in the case of the fixK1 mutant also in anoxic condition. Transcriptomes of nodules from soybean plants infected with the fixJ or fixK2 mutant strains were investigated, too. This study includes also the expression data of a nifA mutant grown in free-living anoxic condition. Samples from GSM210242 to GSM210286 in GEO record number GSE8478 need to be considered for the analyses. Keywords: gene regulation, genetic modification, growth conditions, symbiosis
2008-08-21 | GSE12491 | GEO
Project description:Symbiotic N(2) fixation in Bradyrhizobium japonicum is controlled by a complex transcription factor network. Part of it is a hierarchically arranged cascade in which the two-component regulatory system FixLJ, in response to a moderate decrease in oxygen concentration, activates the fixK(2) gene. The FixK(2) protein then activates not only a number of genes essential for microoxic respiration in symbiosis (fixNOQP and fixGHIS) but also further regulatory genes (rpoN(1), nnrR, and fixK(1)). The results of transcriptome analyses described here have led to a comprehensive and expanded definition of the FixJ, FixK(2), and FixK(1) regulons, which, respectively, consist of 26, 204, and 29 genes specifically regulated in microoxically grown cells. Most of these genes are subject to positive control. Particular attention was addressed to the FixK(2)-dependent genes, which included a bioinformatics search for putative FixK(2) binding sites on DNA (FixK(2) boxes). Using an in vitro transcription assay with RNA polymerase holoenzyme and purified FixK(2) as the activator, we validated as direct targets eight new genes. Interestingly, the adjacent but divergently oriented fixK(1) and cycS genes shared the same FixK(2) box for the activation of transcription in both directions. This recognition site may also be a direct target for the FixK(1) protein, because activation of the cycS promoter required an intact fixK(1) gene and either microoxic or anoxic, denitrifying conditions. We present evidence that cycS codes for a c-type cytochrome which is important, but not essential, for nitrate respiration. Two other, unexpected results emerged from this study: (i) specifically FixK(1) seemed to exert a negative control on genes that are normally activated by the N(2) fixation-specific transcription factor NifA, and (ii) a larger number of genes are expressed in a FixK(2)-dependent manner in endosymbiotic bacteroids than in culture-grown cells, pointing to a possible symbiosis-specific control.
| S-EPMC2566219 | biostudies-literature
Project description:Differential gene expression was analyzed between B. japonicum wild type (Bj110) and aceA mutant (BjΔaceA) exposed to desiccation stress to find AceA regulons under the culture condition.
2015-07-21 | GSE69999 | GEO
Project description:PhyR is an unusual type of response regulator consisting of a receiver domain and an extracytoplasmic function (ECF) sigma factor-like domain. It was recently described as a master regulator of general stress response in Methylobacterium extorquens. Orthologues of this regulator are present in essentially all free-living Alphaproteobacteria. In most of them, phyR is genetically closely linked to a gene encoding an ECF sigma factor. Here, we investigate the role of these two regulators in the soybean symbiont Bradyrhizobium japonicum USDA110. Using deletion mutants and phenotypic assays, we showed that PhyR and the ECF sigma factor sigma(EcfG) are involved in heat shock and desiccation resistance upon carbon starvation. Both mutants had symbiotic defects on the plant hosts Glycine max (soybean) and Vigna radiata (mungbean). They induced fewer nodules than the wild type and these nodules were smaller, less pigmented, and their specific nitrogenase activity was drastically reduced 2 or 3 weeks after inoculation. Four weeks after infection, soybean nodule development caught up to a large extent whereas most mungbean nodules remained defective even 5 weeks after infection. Remarkably, both mutants triggered aberrant nodules on the different host plants with ectopically emerging roots. Microarray analysis revealed that PhyR and sigma(EcfG) control congruent regulons suggesting both regulators are part of the same signalling cascade. This finding was further substantiated by in vitro protein-protein interaction studies which are in line with a partner-switching mechanism controlling gene regulation triggered by phosphorylation of PhyR. The large number of genes of unknown function present in the PhyR/sigma(EcfG) regulon and the conspicuous symbiotic phenotype suggest that these regulators are involved in the Bradyrhizobium-legume interaction via yet undisclosed mechanisms. Comparative analysis of the B. japonicum phyR mutant 8402, ecfG mutant 8404 mutant and the wild type during exponential growth in rich medium (PSY) and after 24 hours starvation in carbon source-free minimal medium
2010-05-16 | E-GEOD-15910 | biostudies-arrayexpress
Project description:A BMP-controlled metabolic-epigenetic signaling cascade directs midfacial morphogenesis
| PRJNA1040221 | ENA
Project description:PhyR is an unusual type of response regulator consisting of a receiver domain and an extracytoplasmic function (ECF) sigma factor-like domain. It was recently described as a master regulator of general stress response in Methylobacterium extorquens. Orthologues of this regulator are present in essentially all free-living Alphaproteobacteria. In most of them, phyR is genetically closely linked to a gene encoding an ECF sigma factor. Here, we investigate the role of these two regulators in the soybean symbiont Bradyrhizobium japonicum USDA110. Using deletion mutants and phenotypic assays, we showed that PhyR and the ECF sigma factor sigma(EcfG) are involved in heat shock and desiccation resistance upon carbon starvation. Both mutants had symbiotic defects on the plant hosts Glycine max (soybean) and Vigna radiata (mungbean). They induced fewer nodules than the wild type and these nodules were smaller, less pigmented, and their specific nitrogenase activity was drastically reduced 2 or 3 weeks after inoculation. Four weeks after infection, soybean nodule development caught up to a large extent whereas most mungbean nodules remained defective even 5 weeks after infection. Remarkably, both mutants triggered aberrant nodules on the different host plants with ectopically emerging roots. Microarray analysis revealed that PhyR and sigma(EcfG) control congruent regulons suggesting both regulators are part of the same signalling cascade. This finding was further substantiated by in vitro protein-protein interaction studies which are in line with a partner-switching mechanism controlling gene regulation triggered by phosphorylation of PhyR. The large number of genes of unknown function present in the PhyR/sigma(EcfG) regulon and the conspicuous symbiotic phenotype suggest that these regulators are involved in the Bradyrhizobium-legume interaction via yet undisclosed mechanisms.
2009-07-01 | GSE15910 | GEO
Project description:Expression data from B. japonicum stress response; aerobic treatment of B. japoncium culture under different stress conditons; pH stress (8 and 4; 4 h); salt stress (80 mM NaCl; 4 h); heat shock (43 °C; 15 min) and temperature stress (35.2 °C; 48 h); as reference wildtype without treatment (AG media; pH 6.9; without NaCl; 28 °C) was used heat shock data were verified by using rpoH-mutant strains B. japonicum 5009; B. japonicum 5032 and B. japonicum 09-32 as described in Narberhaus et al. 1997
2019-12-23 | GSE22388 | GEO
Project description:New target genes controlled by the Bradyrhizobium japonicum two-component regulatory system RegSR
| PRJNA105307 | ENA
Project description:The PhyR-sigmaEcfG signaling cascade is involved in stress response and symbiotic efficiency in Bradyrhizobium japonicum
| PRJNA116905 | ENA