Location: Emerging Pests and Pathogens ResearchTitle: Dissecting the regulon of the two-component system CvsSR: Identifying new virulence genes in Pseudomonas syringae pv. tomato DC3000
Submitted to: International Congress on Molecular Plant-Microbe Interactions
Publication Type: Abstract Only
Publication Acceptance Date: 4/20/2016
Publication Date: 7/16/2016
Citation: Fishman, M., Stodghill, P., Filiatrault, M.J. 2016. Dissecting the regulon of the two-component system CvsSR: Identifying new virulence genes in Pseudomonas syringae pv. tomato DC3000. International Congress on Molecular Plant-Microbe Interactions. P6-141. p. 43.
Technical Abstract: Recognition of environmental changes and regulation of genes that allow for adaption to those changes is essential for survival of bacteria. Two-component systems (TCSs) allow bacteria to sense and adapt to their environment. We previously identified the TCS CvsSR in the bacterial plant pathogen Pseudomonas syringae pv. tomato DC3000 (Pto), and that deltacvsS and deltacvsR strains displayed reduced growth and symptom development in tomato and Arabidopsis thaliana. CvsSR is induced by cations, such as Ca(II), and regulates aggregation and motility in Pto. In order to identify the regulon of CvsSR we used RNA-seq and ChIP-seq. The transcriptional profile of deltacvsR strains compared to wild-type (WT) shows signs of increased oxidative stress and sulfur starvation when grown under Ca(II) concentrations comparable to those found in the tomato leaf apoplast. Similarly, katB and several genes related to sulfur metabolism are found within the primary regulon of CvsSR. This suggests that CvsSR directly regulates the oxidative stress response. A putative carbonic anhydrase encoded by cynT is one of the most highly regulated genes in primary regulon of CvsSR. To investigate if CynT plays a role in virulence of Pto we constructed a deltacynT strain and tested for virulence on tomato. We found that the deltacynT strain showed reduced growth and symptom development in tomato as compared to WT. Carbonic anydrases have antioxidant properties and therefore we speculate CynT acts as an antioxidant in Pto.