Transcriptome-Proteome Profiling in Burkholderia thailandensis during the Transition from Exponential to Stationary...

Burkholderia thailandensis is closely related to, and a surrogate for, highly pathogenic Burkholderia species. Like other bacterial cells, it commonly exists in the stationary phase, for instance, within a host cell. Understanding the molecular mechanisms that characterize the transition from exponential to stationary phases is therefore critical to understanding responses to stress or nutrient limitation. We present here an integrated transcriptomic and proteomic analysis of mRNA and protein abundance changes during entry into the stationary phase. We identified 928 differentially accumulating mRNAs and 832 differentially accumulating proteins. mRNAs encoding proteins involved in benzoate degradation and O-antigen nucleotide sugar biosynthesis were elevated in the stationary phase, whereas processes such as translation and flagellar biosynthesis were downregulated. Proteins related to fatty acid degradation and butanoate metabolism accumulated in the stationary phase along with proteins involved in the synthesis of secondary metabolites. Markedly downregulated proteins in the stationary phase included ribosomal proteins as well as the house-keeping iron-sulfur biogenesis proteins. An only modest correlation between transcriptome and proteome changes was seen, and the RpoS sigma factor was not significantly increased during the stationary phase; RpoS is typically abundant during the stationary phase and critical for expression of stress-response genes. Our data point to distinct adaptive mechanisms, possibly including post-translational regulation.