RNA-seq of PAO1 at two temperatures and at two growth phases

Pseudomonas aeruginosa is a highly versatile bacterium capable of surviving and often thriving in stressful environmental conditions. Here we studied the effect of two environmental conditions, temperature and growth phase, on the P. aeruginosa PAO1 transcriptome. As P. aeruginosa is well-known for its growth-phase dependent phenotypes and gene regulation, our goal was to determine how temperature altered global gene expression at exponential versus stationary phase and to characterize how growth phase affects thermoregulation. To do this, we grew PAO1 in parallel at 25°C and 37°C and sampled the same populations first at exponential phase and then again at stationary phase and assessed gene expression by RNA-sequencing. We also grew PAO1 and an isogenic DlasR mutant at 25°C and 37°C and sampled populations at stationary phase to define LasR-regulated genes at each temperature by RNA-sequencing. This work provides a comprehensive thermoregulon for PAO1 at two distinct growth phases, as well as growth phase transcriptomics at two temperatures, and expands our understanding of quorum sensing regulation under different environmental conditions that P. aeruginosa encounters. Overall design: PAO1 was grown in parallel at two temperatures, 37°C or 25°C, and cultures were sampled for RNA-seq first at exponential phase and then again at stationary phase. PAO1 and an isogenic ?lasR mutant were also grown at 37°C and 25°C to stationary phase and sampled for RNA-seq.