de Lucena, Daniella Karine; Pühler, Alfred; Weidner, Stefan: The role of sigma factor RpoH1 in the pH stress response of Sinorhizobium meliloti. In: BMC Microbiology. Jg.10 H. 1. 2010
Inhalt
- Results
- Identification of sigma factors involved in the pH stress response of S. meliloti
- Transcription profiling of the rpoH1 mutant versus wild type at neutral pH reveals RpoH1 involvement only in the regulation of the rhizobactin operon
- Growth characteristics of S. meliloti wild type and rpoH1 mutant in response to an acidic pH shift
- Effects of an acidic pH shift on S. meliloti wild type and rpoH1 mutant assessed by time-course transcriptome analysis
- Time-course microarray data of S. meliloti wild type following an acidic pH shift were grouped in 6 K-means clusters
- Analysis of expression profiles of the S. meliloti rpoH1 mutant following an acidic pH shift in view of wild type results
- Identification of S. meliloti genes that are regulated in an RpoH1-independent manner following an acidic pH shift
- Identification of S. meliloti genes that are regulated in an RpoH1-dependent manner following an acidic pH shift
- Identification of S. meliloti genes that are regulated in a complex manner following an acidic pH shift
- Functional classification of genes regulated in an RpoH1-dependent manner
- Discussion
- The S. meliloti sigma factor RpoH1 is important for stress response at low pH
- Three groups of S. meliloti genes were found to be transcriptionally regulated upon pH stress in an RpoH1-independent, in an RpoH1-dependent and in a complex manner
- Time-course global gene expression is a powerful tool for the identification of S. meliloti genes regulated by the sigma factor RpoH1
- Conclusions
- Methods
- Bacterial strains, plasmids, and growth conditions
- Construction of sigma factor mutants
- CAS siderophore assay
- Procedures for continuous pH and pH shift growth experiments
- RNA isolation
- Transcriptional profiling using the SM14kOligo whole genome microarray
- Filtering and clustering analysis of the microarray data
- Quantitative RT-PCR analyses
- Microarray data accession numbers
- Acknowledgements
- Author details
- Authors' contributions
- References