PLANT PATHOGENIC FUNGI ARE A SIGNIFICANT THREAT TO GLOBAL FOOD SECURITY. THE FUNGUS, FUSARIUM GRAMINEARUM, IS AN IMPORTANT PATHOGEN OF CEREAL CROPS, SUCH AS WHEAT, BARLEY, AND CORN. THE PATHOGEN REDUCES CROP PRODUCTION AND CONTAMINATES GRAIN WITH TOXIC COMPOUNDS RELEVANT TO HUMAN AND ANIMAL HEALTH. CURRENT STRATEGIES TO MANAGE F. GRAMINEARUM RELY ON THE USE OF CHEMICAL FUNGICIDES. WITH THE OCCURRENCE OF FUNGICIDE-RESISTANCE IN THE PATHOGEN AND GROWING CONCERNS OVER THE ENVIRONMENTAL IMPACT OF FUNGICIDES, THE DEVELOPMENT OF NOVEL STRATEGIES TO MANAGE F. GRAMINEARUM AND OTHER FUNGI IS A CHALLENGE FACING U.S. AGRICULTURE. TO MEET THIS CHALLENGE, A MORE COMPLETE UNDERSTANDING OF HOW FUNGAL PATHOGENS RESPOND TO SIGNALS ASSOCIATED WITH THE HOST ENVIRONMENT IS NEEDED. FACULTATIVE HETEROCHROMATIN IS A TERM USED TO DESCRIBE REGIONS OF DNA THAT ARE INACTIVE DUE TO A SPECIFIC MODIFICATION. THE MODIFICATION ASSOCIATED WITH FACULTATIVE HETEROCHROMATIN IS HISTONE H3 LYSINE-27 TRIMETHYLATION (H3K27ME3). IMPORTANTLY, H3K27ME3 CAN BE REMOVED FROM ONE REGION OF DNA TO MOVED TO ANOTHER. DESPITE EVIDENCE SUGGESTING THAT MOVEMENT OF THE H3K27ME3 MODIFICATION IS IMPORTANT FOR FUNGI TO CAUSE DISEASE, IT IS NOT KNOWN HOW H3K27ME3 IS MOVED IN RESPONSE TO DIFFERENT ENVIRONMENTS. THE MAJOR RESEARCH GOALS OF THIS PROJECT ARE TO UNDERSTAND HOW THE H3K27ME3 MODIFICATION IN F. GRAMINEARUM IS MOVED IN RESPONSE TO THE HOST AND TO DEVELOP AND TEST A NOVEL APPROACH TO CONTROL PLANT DISEASE BY INHIBITING THE PROTEINS RESPONSIBLE FOR H3K27ME3 AND ITS MOVEMENT. TOGETHER, THIS PROJECT WILL INCREASE OUR UNDERSTANDING OF HOW ACTIVE DNA IS REGULATED BY THE H3K27ME3 MODIFICATION DURING FUNGAL PATHOGENESIS AND LEVERAGE FINDINGS TO INVESTIGATE A NOVEL APPROACH TO CONTROL F. GRAMINEARUM AND OTHER FUNGI THAT COULD HAVE BROAD TRANSLATIONAL APPLICATIONS. THESE OUTCOMES WILL CONTRIBUTE TO THE ULTIMATE GOAL OF INCREASING CROP PRODUCTION AND FOOD SECURITY BY MITIGATING THE IMPACT OF FUNGAL PLANT DISEASES AND ASSOCIATED TOXINS.