Leveraging Pathogen Diversity for Gaining Insights into Molecular Plant - Microbe Interactions

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

Plants are exposed to many pathogens and consequently evolved a sophisticated immune system. On the other hand, pathogens evolved sophisticated mechanisms to overcome the plant immune system. In this project, the investigators will take advantage of genetic diversity in pathogen populations and in crop plants to identify pathogen genes and plant genes that determine the outcome of plant-pathogen interactions. These genes can be expected to provide new avenues towards novel approaches in crop disease prevention and control. The project will also offer multiple opportunities for training students in an interdisciplinary and international context. The investigators previously gained new insights into molecular plant-microbe interactions by comparing strains of the tomato pathogen Pseudomonas syringae pv. tomato (Pto) with each other. In particular, they identified the pathogen-associated molecular pattern (PAMP) flgII, which is an epitope within the flagellar filament structural protein (FliC) and which triggers an immune response in tomato and other Solanaceae. To identify additional PAMPs, an international strain collection of Pto and of its close relatives will be expanded in the current project by isolating bacteria from rain, surface water, and crops. Genome sequencing and population genomic analyses will be performed. Pathogen emergence, spread, and crop adaptation will be investigated and new PAMPs and other genes involved in pathogen - plant interaction will be predicted based on signatures of natural selection. Candidate genes will then be tested for their role in pathogen - plant interaction using biochemical and genetic approaches. Such approaches will also be used to identify the tomato receptor of the previously characterized PAMP flgII and, possibly, tomato receptors of other PAMPs that may be identified in the current project.