During the evolution of plant-pathogen interactions, pathogens have acquired the capacity to deliver effector proteins into their plant hosts that re-program host defense signaling systems. This project will employ effectors produced by the oomycete plant pathogen Hyaloperonospora parasitica as molecular probes to elucidate existing and undiscovered defense signaling pathways in Arabidopsis, a major model species for studies in many areas of plant biology. The rationale is that obligate pathogens such as H. parasitica have evolved a sophisticated arsenal of virulence effector proteins that reprogram the host to allow the pathogen to proliferate. Thus, the ability to uncover the targets of these proteins in the host should reveal the function of many unknown genes in the Arabidopsis genome. Furthermore, the specific recognition of these effectors by resistance proteins and the characterization of the subsequently induced signaling pathways will allow us to assign gene function to many uncharacterized genes in these signaling networks. The elucidation of the Arabidopsis targets of the oomycete effector proteins represents a unique opportunity to gain insight into the molecular basis of obligate parasitism and to reveal novel pathways that oomycete pathogens exploit to avoid host detection and incite disease. In its broader impact, this project will potentially facilitate the development of technologies for generating crops with durable and broad-spectrum resistance. The project will also provide opportunities for undergraduates, graduate students and postdoctoral fellows to be trained not only in the biology of classical plant-pathogen interactions but to employ advanced methods of computational biology, genetics, biochemistry, structural and cell biological methods to study these processes.
