MICROBIAL PATHOGENS CAUSE DEVASTATING CROP LOSSES AND SIGNIFICANT FINANCIAL DAMAGE AROUND THE WORLD. FURTHERMORE, A WARMING CLIMATE, PESTICIDE RESISTANCE,AND ENVIRONMENTAL DAMAGE FROM PESTICIDE OVERUSE HAVE MADE THE DEVELOPMENT OF NEW PATHOGEN CONTROL METHODS A NECESSITY. SPRAY-INDUCED GENE SILENCING (SIGS), WHICH RELIES UPON RNA INTERFERENCE, IS AN EFFECTIVE AND SUSTAINABLE METHOD OF DISEASE CONTROL. HOWEVER, SIGS REMAINS LIMITED BY THE INSTABILITY OF RNA IN THE ENVIRONMENT AND ITS DEPENDENCE ON PASSIVE MICROBIAL RNA UPTAKE. INSPIRED BY HOW NANOPARTICLES CAN BE USED TO PROTECT AND DELIVER RNA IN VACCINES, THIS PROJECT WILL DEVELOP PLANT-DERIVED NANOVESICLES (PDNVS) AS A NEW NANOPARTICLE PLATFORM FOR DELIVERING RNA AND OTHER BIOACTIVE MOLECULES TO COMBAT AND STUDY MICROBIAL PATHOGENS. PDNVS FROM DIFFERENT PLANT SOURCES WILL BE EXAMINED FOR THEIR ABILITY TO IMPROVE RNA DELIVERY TO PATHOGENS WITH VARYING INHERENT RNA UPTAKE CAPABILITIES. APPLICATION OF THE RNA-LOADED PDNVS FOR SIGS WILL DETERMINE IF THEY CAN EFFECTIVELY REDUCE PATHOGENICITY AND PROVIDE PROLONGED DISEASE PROTECTION ON PLANTS. THE COMPOSITION OF THE DIFFERENT PDNVS WILL BE ANALYZED TO DETERMINE KEY FEATURES THAT CONTROL RNA LOADING AND PDNV UPTAKE BY DIFFERENT MICROBES. THROUGH THESE EFFORTS, DESIGN RULES TO CREATE TAILORED NANOPARTICLES FOR IMPROVED DISEASE CONTROL WILL BE DEVELOPED. OVERALL, THIS WORK WILL DEMONSTRATE HOW PDNVS CAN BE USED TO EXTEND SIGS TO PREVIOUSLY UNTREATABLE MICROBES AND PROVIDE VALUABLE INFORMATION ON HOW TO DEVELOP MORE ROBUST AND EFFECTIVE ANTIMICROBIAL STRATEGIES FOR AGRICULTURE AND HUMAN HEALTH.