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POSTERS: Plant defense response

Using network analysis to uncover interactions between host defense signaling pathways and virulence effectors of Pseudomonas syringae pv. tomato
Alex Turo - Ohio State University. David Mackey- Ohio State University

Interactions between plants and phytopathogenic bacteria depend on the interactions of host defense pathways and virulence effectors. Among the arsenal of effectors of Pseudomonas syringae pv. tomato (Pto), the phytotoxin coronatine (COR) and the functionally-redundant type-III effectors AvrE1 and HopM1 make key contributions to virulence on host plants. While these effectors perform partially-overlapping functions by interacting with distinct host targets, our understanding of how their activities are coordinated through downstream pathways is unclear. Arabidopsis thaliana employs a hormone-dependent signaling network to coordinate host defense, including against Pto. COR, AvrE1 and HopM1 directly and indirectly target the salicylic acid, jasmonate, ethylene, and indole glucosinolate-dependent sectors of this network. We have constructed polymutant sets of both Pto and Arabidopsis for all combinations of these effectors and pathways and will measure the interaction of these strains and plants, at both the level of bacterial growth and plant immune responses. This approach will enable network analysis to reveal contributions of interacting effectors and pathways during plant-bacterial interactions.