Elucidation of roles that protein acetylation plays in mediating plant-pathogen interactions

Crop loss due to pathogens threatens global food security and represents a major source of economic loss. A thorough understanding of how pathogens cause disease and how plants defend themselves is crucial for addressing food security challenges. How pathogens manipulate their host to enable infection and how plants counteract the pathogen are major outstanding questions in the field. Pathogen infection triggers complex molecular changes within host cells that result in either resistance or susceptibility. One emerging widespread biochemical modification to proteins is acetylation, which can change activity of the protein and can be measured globally using mass spectrometry. This project aims to determine the extent of and the role of pathogen triggered changes in protein acetylation state in the model plants corn and Arabidopsis. The results of these studies may provide a novel approach to engineering plant disease resistance via mimicking or blocking the ability of particular proteins to be modified (acetylated). The project will provide cutting edge training in functional genomics to undergraduate, graduate, and postdoctoral students, including underrepresented minorities through the George Washington Carver Internship Program at Iowa State University. <br/><br/>The long-term goal of this project is to understand the molecular regulatory events mediated by protein lysine acetylation that govern the interplay between plants and microbes, using maize and Arabidopsis interactions with Cochliobolus heterostrophus and Botrytis cinerea as prototypes. Comprehensive -omics profiling will be coupled with directed biochemical and genetic experiments to define the molecular roles of lysine acetylation underpinning plant biotic stress responses. Sequencing of DNA enriched by chromatin-immunoprecipitation will define promoters that exhibit histone hyperacetylation and/or recruitment of transcriptional regulatory proteins following pathogen infection or effector treatment (HC-toxin). These data will be coupled with genome-wide profiling of mRNA and protein abundance, in several genetic backgrounds, following pathogen challenge to identify genes directly regulated by ZmMYC2 and REL2. Functional characterization of ZmMYC2 and REL2 will establish how acetylation of these proteins modulates their transcriptional regulatory activity. Analyses of acetylome profiling data generated from pathogen-infected maize and Arabidopsis plants will define how widespread dynamic lysine acetylation is during plant-pathogen interactions. Altogether this research will assess the impact of non-histone protein acetylation during plant-pathogen interactions and will compare and contrast the contributions of histone and non-histone acetylation in shaping the immune response.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.