Project description:Sinorhizobium meliloti can live as a soil saprophyte, and can engage in a nitrogen fixing symbiosis with plant roots. To succeed in such diverse environments, the bacteria must continually adjust gene expression. Transcriptional plasticity in eubacteria is often mediated by alternative sigma factors interacting with core RNA polymerase. The S. meliloti genome encodes 14 of these alternative sigmas, including two putative RpoH (heat shock) sigmas. We used custom Affymetrix Symbiosis Chips to characterize the global transcriptional response of S. meliloti rpoH1, rpoH2 and rpoH1 rpoH2 mutants during heat shock and stationary phase growth. Under these conditions, expression of over 300 genes is dependent on rpoH1 and rpoH2.
Project description:We characterized transcriptomes of a Sinorhizobium meliloti rpoH1rpoH2 deletion mutant (RFF231; Lang et al. 2018, mSphere 3:e00454-18) expressing either Ca. Liberibacter asiaticus rpoH or Sinorhizobium meliloti rpoH1
Project description:Sinorhizobium meliloti can live as a soil saprophyte, and can engage in a nitrogen fixing symbiosis with plant roots. To succeed in such diverse environments, the bacteria must continually adjust gene expression. Transcriptional plasticity in eubacteria is often mediated by alternative sigma factors interacting with core RNA polymerase. The S. meliloti genome encodes 14 of these alternative sigmas, including two putative RpoH (heat shock) sigmas. We used custom Affymetrix Symbiosis Chips to characterize the global transcriptional response of S. meliloti rpoH1, rpoH2 and rpoH1 rpoH2 mutants during heat shock and stationary phase growth. Under these conditions, expression of over 300 genes is dependent on rpoH1 and rpoH2. Gene expression profiling of Sinorhizobium meliloti Rm1021 and its isogenic rpoH1, rpoH2, and rpoH1rpoH2 mutants, subjected to heat shock or stationary phase growth, was performed using custom Affymetrix GeneChips
Project description:We characterized transcriptomes for strains overexpressing each of the Sinorhizobium meliloti ECF sigma factors the via a plasmid-borne, melibiose-inducible promoter plasmid (PmelA; pCAP11: Pinedo et al. 2008 J Bacteriol 190:2947-2956) compared to control strains carrying the empty vector.
Project description:Sinorhizobium meliloti lives as a soil saprophyte, and engages in a nitrogen fixing symbiosis with plant roots. To succeed in such diverse environments, the bacteria must continually adjust gene expression. Transcriptional plasticity in eubacteria is often mediated by alternative sigma factors interacting with core RNA polymerase. The S. meliloti genome encodes 14 of these alternative sigmas, including 11 extracytoplasmic function (ECF) sigmas. We used custom Affymetrix Symbiosis Chips to characterize the global transcriptional response of S. meliloti overexpressing the ECF sigma factor, RpoE2. Our work identifies over 200 genes whose expression is dependent on RpoE2.
Project description:Sinorhizobium meliloti lives as a soil saprophyte, and engages in a nitrogen fixing symbiosis with plant roots. To succeed in such diverse environments, the bacteria must continually adjust gene expression. Transcriptional plasticity in eubacteria is often mediated by alternative sigma factors interacting with core RNA polymerase. The S. meliloti genome encodes 14 of these alternative sigmas, including 11 extracytoplasmic function (ECF) sigmas. We used custom Affymetrix Symbiosis Chips to characterize the global transcriptional response of S. meliloti overexpressing the ECF sigma factor, RpoE2. Our work identifies over 200 genes whose expression is dependent on RpoE2. The gene expression profile of Sinorhizobium meliloti strain CL150 carrying the rpoE2 gene on a plasmid, where it was expressed from a melibiose-inducible promoter (the S. meliloti PmelA promoter), was compared to the gene expression profile of CL150 carrying the corresponding empty vector (pCAP11). CL150 is an Rm1021 strain that has been corrected for two point mutations: it is wild type for ecfR1 and pstC.
Project description:We characterized transcriptomes of a Sinorhizobium meliloti wild type strain (CL150) expressing either Ca. Liberibacter asiaticus ctrA or Sinorhizobium meliloti ctrA
Project description:The Alphaproteobacterium Sinorhizobium meliloti lives in soil and is capable of fixing molecular nitrogen in symbiosis with legume plants. In this work, the small proteome of S. meliloti strain 2011 was studied to uncover translation of both annotated and novel small open reading frame (sORF)-encoded proteins (SEPs).
