Project description:The purpose of the study is to identify iron-responsive genes in the bacterium Bradyrhizobium japonicum. Parent strain LO was grown under iron limitation or under iron sufficiency and compared to each other by whole genome microarray analysis. Keywords: Comparison of cells grown under low or high iron conditons
Project description:The purpose of the study is to identify Irr-responsive genes in the bacterium Bradyrhizobium japonicum. Parent strain LO was compared to irr mutant strain LODTM5 by whole genome microarray analysis. Both cell types were grown in iron-limited media. Keywords: Comparison of B. japonicum wild type and mutant cells
Project description:Analysis of a Bradyrhizobium japonicum pmtA mutant. PmtA catalyzes the first of three consecutive methylation reactions leading to phosphatidylcholine (PC) formation in B. japonicum. Disruption of the pmtA gene results in a significantly reduced PC content causing a defect in symbiosis with the soybean host. This study provides the first insight into global transcriptomic changes of a bacterial phosphatidylcholine biosynthesis mutant. Cells of the pmtA mutant and the wild type were grown to mid-exponential phase in full medium (PSY) under aerobic culture conditions. Keywords: genetic modification
Project description:Analysis of a Bradyrhizobium japonicum pmtA mutant. PmtA catalyzes the first of three consecutive methylation reactions leading to phosphatidylcholine (PC) formation in B. japonicum. Disruption of the pmtA gene results in a significantly reduced PC content causing a defect in symbiosis with the soybean host. This study provides the first insight into global transcriptomic changes of a bacterial phosphatidylcholine biosynthesis mutant. Cells of the pmtA mutant and the wild type were grown to mid-exponential phase in full medium (PSY) under aerobic culture conditions. Keywords: genetic modification Comparative analyis of the B. japonicum pmtA mutant and the wild type grown under aerobic culture conditions.
Project description:The Bradyrhizobium japonicum NtrC regulatory protein influences gene expression in response to changes in intracellular nitrogen status. Under conditions of low nitrogen, phosphorylation of NtrC results in up-regulation of a number of genes involved in nitrogen metabolism and nitrogen acquisition. To better define the exact nature of NtrC’s influence on gene expression, a ntrC mutation was created in B. japonicum and transcriptional profiling was performed by DNA microarray analysis of both the mutant and wild type strains. Bradyrhizobium japonicum USDA 110 and a ntrC mutant in the USDA 110 background were cultured in minimal medium supplemented with either 10mM glutamate (low nitrogen) or 10mM ammonium and 10mM glutamate (high nitrogen) as nitrogen sources. Four comparisons were performed: wild type high nitrogen vs. mutant high nitrogen, wild type low nitrogen vs. wild type high nitrogen, wild type low nitrogen vs. mutant low nitrogen, and mutant low nitrogen vs. mutant high nitrogen. For each of the four comparisons, three biological replicates were prepared for each strain and dye swap replications were performed for each hybridization producing a total of six arrays per comparison and 24 arrays in total.
Project description:The Bradyrhizobium japonicum NtrC regulatory protein influences gene expression in response to changes in intracellular nitrogen status. Under conditions of low nitrogen, phosphorylation of NtrC results in up-regulation of a number of genes involved in nitrogen metabolism and nitrogen acquisition. To better define the exact nature of NtrC’s influence on gene expression, a ntrC mutation was created in B. japonicum and transcriptional profiling was performed by DNA microarray analysis of both the mutant and wild type strains.
Project description:The Bradyrhizobium japonicum NtrC regulatory protein influences gene expression in response to changes in intracellular nitrogen status. Under conditions of low nitrogen, phosphorylation of NtrC results in up-regulation of a number of genes involved in nitrogen metabolism and nitrogen acquisition. To better define the exact nature of NtrC’s influence on gene expression, a ntrC mutation was created in B. japonicum and transcriptional profiling was performed by DNA microarray analysis of both the mutant and wild type strains.
Project description:Elevated atmospheric CO2 can influence the structure and function of rhizosphere microorganisms by altering root growth and the quality and quantity of compounds released into the rhizosphere via root exudation. In these studies we investigated the transcriptional responses of Bradyrhizobium japonicum cells growing in the rhizosphere of soybean plants exposed to elevated atmospheric CO2. Transciptomic expression profiles indicated that genes involved in carbon/nitrogen metabolism, and FixK2-associated genes, including those involved in nitrogen fixation, microanaerobic respiration, respiratory nitrite reductase, and heme biosynthesis, were significantly up-regulated under conditions of elevated CO2, relative to plants and bacteria grown under ambient CO2 growth conditions. The expression profile of genes involved in lipochitinoligosaccharide Nod factor biosynthesis and negative transcriptional regulators of nodulation genes, nolA and nodD2, were also influenced by plant growth under conditions of elevated CO2. Taken together, results of these studies indicate that growth of soybeans under conditions of elevated atmospheric CO2 influences gene expressions in B. japonicum in the soybean rhizosphere, resulting in changes to carbon/nitrogen metabolism, respiration, and nodulation efficiency. Bradyrhizobium japonicum strains were grown in the soybean rhizosphere under two different CO2 concentrations. Transcriptional profiling of B. japonicum was compared between cells grown under elevated CO2 and ambient conditions. Four biological replicates of each treatment were prepared, and four microarray slides were used for each strain.
Project description:Elevated atmospheric CO2 can influence the structure and function of rhizosphere microorganisms by altering root growth and the quality and quantity of compounds released into the rhizosphere via root exudation. In these studies we investigated the transcriptional responses of Bradyrhizobium japonicum cells growing in the rhizosphere of soybean plants exposed to elevated atmospheric CO2. The results of microarray analyses indicated that atmospheric elevated CO2 concentration indirectly influences on expression of large number of Bradyrhizobium genes through soybean roots. In addition, genes involved in C1 metabolism, denitrification and FixK2-associated genes, including those involved in nitrogen fixation, microanaerobic respiration, respiratory nitrite reductase, and heme biosynthesis, were significantly up-regulated under conditions of elevated CO2 in the rhizosphere, relative to plants and bacteria grown under ambient CO2 growth conditions. The expression profile of genes involved in lipochitinoligosaccharide Nod factor biosynthesis and negative transcriptional regulators of nodulation genes, nolA and nodD2, were also influenced by plant growth under conditions of elevated CO2. Taken together, results of these studies indicate that growth of soybeans under conditions of elevated atmospheric CO2 influences gene expressions in B. japonicum in the soybean rhizosphere, resulting in changes to carbon/nitrogen metabolism, respiration, and nodulation efficiency.