Exchange of small molecules between host and pathogen lies at the heart of cellular decisions in both organisms that result in either compatible (i.e. disease) or incompatible (i.e. resistance) interactions. A subset of these molecules are oxygenated lipids (oxylipins) produced by conserved oxygenases in both organisms. Of intellectual and potential economical significance is the investigators' recent discovery that maize and fungal volatile and non-volatile oxylipins play a pivotal role in fungal growth, spore and toxin production by Aspergillus flavus, a major seed infecting fungus that produces the carcinogenic mycotoxin aflatoxin. Our central hypothesis is that fungi and plants induce, intercept and recognize each others oxylipins and that these interactions direct the outcome of the host-pathogen interaction. The overall goal of this project is to elucidate molecular, biochemical and cellular mechanisms governing oxylipin regulation and perception in both maize and A. flavus. By using oxylipin mutants in both organisms, the investigators will assess the role of these lipid molecules in seed colonization, fungal development and aflatoxin production. They will also test the hypothesis that maize oxylipins are perceived by A. flavus G-protein coupled receptors to modulate pathogenesis processes. The results will generate conclusive evidence of cross kingdom lipid-based signaling communication that governs the outcomes of host-pathogen interactions. These results will be of significance to the scientific community involved in studies of cross-talk signaling in plant-insect, animal- and human-pathogen interactions. The broader impacts of this project include insights required for the incorporation of mycotoxin resistance into commercial germplasm, an advance of immediate significance for the general public, seed industry, maize growers and breeders. A key component of this project is to train graduate students and postdocs in cross-disciplinary fields of plant and fungal genetics, molecular biology and lipid biochemistry and mentoring of undergraduates in laboratory and class settings.
