NON-TECHNICAL SUMMARYCOTTON (GOSSYPIUM HIRSUTUM) IS OUR MOST IMPORTANT FIBER CROP. YIELD AND QUALITY ARE UNDERMINED BY PESTS AND PATHOGENS, INCLUDING COTTON APHIDS AND FUSARIUM FUNGAL INFECTIONS. PLANT-SYNTHESIZED OXYLIPINS, SPECIFICALLY 9-HYDROXY FATTY ACIDS RESULTING FROM 9-LIPOXYGENASE ACTIVITY (9-LOX), ARE FEEDING STIMULANTS FOR MANY PESTS, AND REDUCED LEVELS OF THESE COMPOUNDS IN CROP PLANTS CAN PROVIDE PROTECTION. ADDRESSING USDA PROGRAM AREA CRITICAL AGRICULTURAL RESEARCH AND EXTENSION (A1701), WE PROPOSE TO DEVELOP GENOME EDITING APPROACHES TO CONFER NATURAL RESISTANCE AGAINST DEVASTATING COTTON APHID AND FUSARIUM WILT BY ELUCIDATING OXYLIPIN SIGNALING AND MANIPULATING ITS DERIVATIVES. FIRST, WE WILL FUNCTIONALLY TEST GENES ENCODING 9-LOX ENZYMES USING VIRUS-INDUCED GENE SILENCING. WE PREDICT THIS WILL REDUCE 9-HYDROXY FATTY ACIDS LEVELS AND DETER APHID AND FUSARIUM INFESTATIONS. SECOND, WE WILL INTRODUCE STABLE GENETIC ALTERATIONS TO GHLOX GENES USING NEW CRISPR-MEDIATED GENE EDITING APPROACHES, AND TEST THAT THESE ARE HERITABLE AND CONFER RESISTANCE AGAINST APHIDS AND FUSARIUM. WE AIM TO ACCELERATE THESE GENE-EDITING STRATEGIES BY INCORPORATING INDUCIBLE GENES PROMOTING SOMATIC EMBRYOGENESIS AND WHOLE-PLANT REGENERATION. THIRD, BY EXPLOITING A NEW APPROACH FOR MAKING PLANT MERISTEMS MORE SUSCEPTIBLE TO GENETIC MANIPULATION, WE AIM TO DEVELOP A NOVEL, MERISTEM-BASED GENE-EDITING SYSTEM TO ACHIEVE STABLE ALTERATIONS IN GERMLINE CELLS AND BY-PASS THE NEED FOR TISSUE CULTURE. THIS HIGH-RISK OBJECTIVE MAY REVOLUTIONIZE BIOTECHNOLOGY APPROACHES TO IMPROVE COTTON AGRICULTURE. THIS PROPOSAL IS SUBMITTED AS A CO-FUNDED PRIORITY WITH THE COTTON BOARD TO DEVELOP NEW GENOME EDITING-ENABLED APPROACHES TO PROTECT COTTON FROM DAMAGING INSECT PESTS WITH THE POTENTIAL TO CONSIDERABLY REDUCE PESTICIDE USE, PRESERVE CURRENT TECHNOLOGIES, AND MAINTAIN YIELDS.