**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 PESTS AND DISEASES ARE A SIGNIFICANT CAUSE OF ECONOMIC LOSS DUE TO REDUCED YIELD AND QUALITY OF HUMAN AND ANIMAL FOOD CROPS THAT INCLUDE BUT ARE NOT LIMITED TO SOYBEAN, CORN, AND WHEAT. PLANTS, LIKE HUMANS AND OTHER ANIMALS, HAVE IMMUNE SYSTEMS RESPONSIBLE FOR PROTECTION AGAINST DISEASES CAUSED BY PESTS AND PATHOGENS. RESEARCH CONDUCTED BY SCIENTISTS SINCE THE 1940S FOCUSED ON UNDERSTANDING THE PARTS AND FUNCTIONSOF THE PLANT IMMUNE SYSTEM, AND PROVIDED THE BASIC KNOWLEDGE REQUIRED TO DEVELOP PLANT VARIETIES THAT ARE TOLERANT OR RESISTANT TO PATHOGENS LIKE BACTERIA, VIRUSES, AND FUNGI. HOWEVER, IT WAS NOT UNTIL RECENTLY THAT WE BEGAN TO INVESTIGATE HOW THE PLANT IMMUNE SYSTEM RESPONDS TO PESTS LIKE DEVASTATING CATERPILLARS, AND WHETHER EXISTING RESISTANCE TO BACTERIA CAN AFFECT RESISTANCE TO CATERPILLARS OR VICE VERSA. THIS IS OF GREAT RELEVANCE TO OUR AGRICULTURE SINCE CROPS ARE CONSTANTLY CHALLENGED BY MULTIPLE TYPES OF PESTS AND PATHOGENS, AND THEIR IMMUNE SYSTEMS MIGHT BE ABLE TO PROTECT AGAINST ONE, BUT NOT BOTH AT THE SAME TIME. EVEN MORE CONCERNING, EXISTING RESISTANCE TO ONE MIGHT LEAD TO INCREASED SUSCEPTIBILITY TO THE OTHER, RESULTING IN EQUAL OR GREATER CROP LOSS.IN THIS PROPOSAL I SEEK TO ADDRESS THIS GAP IN KNOWLEDGE BY STUDYING HOW THE PLANT IMMUNE SYSTEM RESPONDS TO SIMULTANEOUS AND/OR SEQUENTIAL EXPOSURE TO AGRICULTURALLY RELEVANT BACTERIA AND CATERPILLARS. MY SPECIFIC GOALS ARE 1) TO DETERMINE IF PLANTS THAT RECOGNIZE BACTERIA AND CATERPILLARS AT THE SAME TIME HAVE COMPROMISED IMMUNE RESPONSES, AND 2) TO ASSESS THE EFFECT ON PLANT RESISTANCE TO ONE OR THE OTHER WHEN THEY COEXIST OR SEQUENTIALLY APPEAR. TO ACCOMPLISH THIS, I WILL CHALLENGE BEAN PLANTS WITH BACTERIA EXTRACTS AND/OR CATERPILLAR SALIVA, AND I WILL MEASURE THE IMMUNE RESPONSE IN TERMS OF GENE EXPRESSION AND PLANT HORMONE PRODUCTION COMPARED TO A PLANT THAT BEEN EXPOSED TO ONLY ONE OR THE OTHER. THEN, I WILL INFECT BEAN PLANTS IN A LABORATORY SETTING USING AGRICULTURALLY RELEVANT BACTERIA, CATERPILLARS, OR BOTH, AND I WILL MEASURE HOW MUCH DAMAGE THE PLANT SUSTAINS IN TERMS OF AMOUNT OF LEAF EATEN, CATERPILLAR WEIGHT GAIN, AND SYMPTOMS OF BACTERIAL INFECTION. I EXPECT THAT THE OUTPUTS OF THIS RESEARCH WILL EXPAND OUR CURRENT UNDERSTANDING OF THE PLANT IMMUNE SYSTEM THAT COULD BE APPLIED TO DEVELOP NEW CROP VARIETIES ABLE TO WITHSTAND DIFFERENT TYPES OF PESTS AND PATHOGENS AND WILL MOTIVATE FURTHER RESEARCH INTO THE IMPACT THAT MULTIPLE INFECTIONS COULD HAVE IN THE FIELD (E.G., YIELD REDUCTION, CROP LOSS).