Involvement of rppH in Thermo-regulation in Pseudomonas syringae.

Journal of bacteriology

PubMedID: 24727227

Hockett KL, Ionescu M, Lindow SE. Involvement of rppH in Thermo-regulation in Pseudomonas syringae. J Bacteriol. 2014;.
Temperature, among other environmental factors, influences the incidence and severity of many plant diseases. Likewise, numerous traits, including expression of virulence factors, are regulated by temperature. Little is known about the underlying genetic determinants of thermo-regulation in plant-pathogenic bacteria. Previously, we showed that expression of both fliC (encoding flagellin) and syfA (encoding a non-ribosomal polypeptide synthetase) were suppressed at high temperatures in Pseudomonas syringae. In this work, we use a high-throughput screen to identify mutations that conferred over-expression of syfA at elevated temperatures (28 °C compared to 20 °C). Two genes, Psyr_2474, encoding an acyl-CoA dehydrogenase, and Psyr_4843, encoding an ortholog of RppH, which in E. coli mediates RNA turnover contribute to thermo-regulation of syfA. To assess the global role of rppH in thermo-regulation in P. syringae, RNA sequencing was used to compare the transcriptomes of an rppH deletion mutant with the wild type strain incubated at 20 °C and 30 °C. Disruption of rppH had a large effect on the temperature-dependent transcriptome of P. syringae, affecting expression of 569 genes at either 20 °C or 30 °C, but not both temperatures. Intrigingly, RppH is involved in thermo-regulation of ribosome-associated proteins as well as RNase E, suggesting a prominent role of rppH on the proteome in addition to its effect on the transcriptome.