Genes and phenotypes controlled by the Gac-rsm pathway in Pseudomonas syringae pv. tomato DC3000

Pseudomonas syringae pv. tomato (Pto) DC3000 is a model bacteria used to study plant-phytopathogen interactions. It was previously established that the Gac-Rsm pathway controls virulence, multiplication in plant, hypersensitive response (HR) induction efficiency, pigment and N-acyl-homoserine lactone production, and swarming. Pto DC3000 possesses seven small RNAs controlled by GacS/GacA and five RsmA-like RNA binding proteins. The overall objective of the present work is the characterization of the Pto DC3000 Gac-Rsm pathway and the elucidation of its physiological role. The specific objectives are the study of the expression and regulation of: 4. The Rsm regulatory proteins. 5. The Rsm regulatory RNAs. 6. The target mRNAs of the Gac-Rsm pathway. This study will be tackled from a multidisciplinary point of view, using new methodologies like bioinformatics, genomic, proteomic, combined with cellular and molecular approaches. Mutant strains in the component of the Gac-Rsm pathway and target genes will be constructed and phenotypically characterised. We will focus on phenotypes important for plant colonization and symptom development, like swimming, swarming, virulence factor production, biosurfactant, EPS or siderophore synthesis. Also, gene expression will be analysed under diverse conditions (laboratory media, in planta, etc.) by different in vivo and in vitro methods.