**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** PLANT RHABDOVIRUSES REPRESENT THE NEXT GENERATION OF VIRAL VECTORS FOR DELIVERY OF PROTEINS AND RNAS TO PLANTS AND INSECTS. BECAUSE OF THEIR LARGE CARRYING CAPACITY, THERE IS SIGNIFICANT INTEREST IN USING RHABDOVIRUSES FOR GENOME EDITING. RHABDOVIRUSES REPLICATE IN THEIR PLANT HOSTS AND INSECT VECTORS, THUS CREATING A COMPLEX OPPORTUNITY FOR UNDERSTANDING RISKS ASSOCIATED WITH USING THESE TYPES OF VIRUSES AS DELIVERY SYSTEMS. WE PROPOSE TO USE OUR RECENTLY DEVELOPED INFECTIOUS CLONE FOR MAIZE MOSAIC VIRUS (MMV) AS A MODEL FOR UNDERSTANDING RISKS ASSOCIATED WITH RHABDOVIRUS VECTORS. WE WILL CHARACTERIZE THE ENVIRONMENTAL RISK FOR VECTOR TRANSMISSION OF GENETICALLY MODIFIED MMV TO AGRONOMIC AND WILD GRASS SPECIES (FAMILY POACEAE). WE WILL STUDY VIRUS RECOMBINATION OF THE GENETICALLY MODIFIED VIRUS TO DETERMINE THE POTENTIAL FOR GENETIC EXCHANGE BETWEEN MODIFIED MMV AND WILDTYPE (WT) MMV. TO REDUCE RISK OF VIRUS ESCAPE AND INCREASE UTILITY IN THE FIELD WE WILL CREATE REDUCED-RISK VIRAL VECTORS THAT ARE COMPETENT FOR PLANT INFECTION BUT ARE NO LONGER INSECT TRANSMISSIBLE. THE PROJECT OUTCOMES WILL PROVIDE FEDERAL REGULATORY AGENCIES WITH IMPORTANT INFORMATION ABOUT THE SPECIFIC HOST RANGE OF MMV AND THE UTILITY OF THIS SPECIFIC VIRUS VECTOR. THE PROJECT TEAM IS WELL EQUIPPED TO CONDUCT THE PROPOSED RESEARCH WITH GENETICALLY MODIFIED VIRUSES AND VECTORS AND ALL WORK WILL BE CONDUCTED IN PROPER CONTAINMENT FACILITIES AND WITH APPROPRIATE PERMITS.