PLANTS UTILIZE MULTIPLE INNATE DEFENSE RESPONSES WHEN CHALLENGED BY DISEASE. CURRENTLY, THERE ARE GAPS IN OUR UNDERSTANDING OF GENES INVOLVED IN THESE MECHANISMS AND HOW THESE GENES FUNCTION IN DEFENSE. IN ADDITION, MANY OF THE NATURAL DEFENSE COMPOUNDS PLANTS PRODUCE IN RESPONSE TO INFECTION HAVE NOT BEEN CHARACTERIZED. THIS PROJECT USES CORN AS A MODEL SYSTEM AND AIMS TO IDENTIFY GENES INVOLVED IN PLANT DEFENSE AND CHARACTERIZE HOW PLANT METABOLISM IS ALTERED DURING DEFENSE RESPONSE. CURRENT APPROACHES TO STUDY PLANT DEFENSE RESPONSE REQUIRE TREATMENT WITH BIOLOGICAL PATHOGENS AND THUS ANY DATA INTERPRETATION REQUIRES SEPARATING THE GENES AND METABOLITES PRODUCED BY THE PLANT FROM THOSE PRODUCED BY THE PATHOGEN. ALTERNATIVELY, THIS WORK UTILIZES THE LESION MIMIC MUTANTS (LMMS), WHICH ARE A DIVERSE CLASS OF MUTANTS, SOME OF WHICH MIMIC PLANT DEFENSE RESPONSES IN THE ABSENCE OF INFECTION OR DISEASE. SINCE LMMS DO NOT REQUIRE PATHOGEN INFECTION TO ELICIT DEFENSE RESPONSE, THEY CAN EASILY BE STUDIED IN BOTH GREENHOUSE AND FIELD CONDITIONS AND ALL MEASURED METABOLITE AND GENE PRODUCTS CAN BE ATTRIBUTED TO THE BIOLOGY OF THE PLANT. IN THIS PROJECT, I WILL USE BIOCHEMICAL TECHNIQUES TO MEASURE THE METABOLITE PROFILE OF OVER 40 DIFFERENT CORN LMMS AND UTILIZE A GENETIC MAPPING APPROACH TO IDENTIFY GENES ENCODING LMMS. THE KNOWLEDGE GAINED FROM THIS WORK WILL INCLUDE CHARACTERIZATION OF NATURAL PRODUCTS PRODUCED BY PLANTS DURING DEFENSE RESPONSE AS WELL AS IDENTIFICATION OF NOVEL GENE CANDIDATES THAT FUNCTION IN DEFENSE RESPONSE PATHWAYS.