THE GOAL OF THIS STUDY IS TO HELP DEVELOP SAFE AND EFFECTIVE METHODS TO CONTROL PARASITIC NEMATODES AND OTHER SOIL-BORNE DISEASES ON SOYBEAN AND OTHER CROPS. SOYBEAN IS THE SECOND LARGEST CROP IN THE US, AND AMERICAN SOYBEAN GROWERS SUFFER BILLIONS OF DOLLARS IN YIELD LOSSES TO NEMATODES AND OTHER SOIL-BORNE PATHOGENS EVERY YEAR. MOREOVER, MANY OF THESE SOIL-BORNE PATHOGENS, INCLUDING ROOT-KNOT NEMATODES, ATTACK A WIDE VARIETY OF OTHER CROPS AS WELL. CHEMICAL CONTROLS FOR SOIL-BORNE PATHOGENS ARE BECOMING INCREASINGLY LIMITED DUE TO CONCERNS ABOUT THEIR ENVIRONMENTAL IMPACTS AND WORKER SAFETY. THEREFORE, THERE IS A PRESSING NEED TO DEVELOP ALTERNATIVE TECHNIQUES FOR THE MANAGEMENT OF NEMATODES AND OTHER ROOT DISEASES. THIS PROJECT SEEKS TO UTILIZE PLANTS' OWN NATIVE SIGNALING MOLECULES, CALLED PLANT ELICITOR PEPTIDES (PEPS), TO IMMUNIZE PLANTS AGAINST ATTACK BY NEMATODES AND OTHER ROOT-INFECTING PATHOGENS. WE WILL EXPLORE THREE DIFFERENT APPROACHES TO INCREASE THE ACCUMULATION OF PEPS IN SOYBEAN, AND WE WILL TEST THE EFFECTS OF THESE APPROACHES ON PLANT GROWTH, HEALTH, AND YIELDS, IN ADDITION TO THEIR EFFECTS ON INFECTION BY NEMATODES AND ECONOMICALLY-DAMAGING PATHOGENS. WE WILL ALSO MORE BROADLY ASSESS THE EFFECTS OF THESE TREATMENTS ON SOIL HEALTH, OR THE BALANCE BETWEEN PATHOGENIC AND BENEFICIAL MICROBES IN THE SOIL. IF PEPS PROVE USEFUL FOR CROP PROTECTION IN SOYBEAN, OUR RESULTS COULD IN THE FUTURE BE EXTENDED TO MANY OTHER CROPS, BECAUSE THESE SIGNALING COMPOUNDS ARE FOUND IN A WIDE RANGE OF PLANT SPECIES. THIS RESEARCH SEEKS TO ENABLE BIOLOGICALLY-BASED PEST MANAGEMENT, WHICH ENHANCES OUR AGRICULTURAL ECONOMY WHILE ALSO CONTRIBUTING TO FOOD SAFETY AND ENVIRONMENTAL PROTECTION.