** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** AN ORGANISM'S ABILITY TO RESPOND TO ITS ENVIRONMENT IS FUNDAMENTAL TO ITS SURVIVAL. WHEN THE ORGANISM OF INTEREST IS INVOLVED IN A HOST-PATHOGEN INTERACTION, THE ENVIRONMENT BECOMES COMPLEX: IT INCLUDES NOT ONLY EXTERNAL FORCES, BUT ALSO THE CONDITIONS IMPOSED BY THE INTERACTING PARTNER. THERE ARE ALSO TWO GENOMES AT PLAY; EACH OF WHICH AFFECTS THE BEHAVIOR OF BOTH ORGANISMS. OF COURSE, EXTERNAL ENVIRONMENTAL FORCES IMPOSE ADDITIONAL PRESSURES, AND EACH GENOME CAN AFFECT HOW BOTH PARTNERS RESPOND. THIS PROJECT EXAMINES THE ROLE THE HOST GENOME PLAYS IN ALTERING BEHAVIOR OF BOTH HOST AND PATHOGEN UNDER ENVIRONMENTAL STRESS. IT LEVERAGES AN AGRICULTURALLY RELEVANT SYSTEM: NEMATODE INFECTION OF TOMATO. PARASITIC NEMATODES ARE RESPONSIBLE FOR AROUND $125 BILLION IN ANNUAL CROP LOSS WORLDWIDE, AND IN TOMATO, YIELD LOSS CAN BE UPWARDS OF 80%. LIMITED CONTROL OPTIONS ARE AVAILABLE. THE SITUATION IS EXACERBATED BY AN EMERGING CONCERN IN AGRICULTURE: THE EFFECT OF WARMING NIGHTTIME TEMPERATURES (WNT). THIS UNPRECEDENTED TREND IS CAUSING CRITICAL CHALLENGES TO CROPS. THIS PROJECT DEVELOPS NOVEL APPROACHES TO EXAMINE HOST-PATHOGEN INTERACTIONS AND HOW THEY ARE AFFECTED BY EXTERNAL CONDITIONS. BROADER, FUTURE IMPACTS OF THIS WORK INCLUDE THE ABILITY TO IDENTIFY PLANT LINES THAT ARE MORE RESILIENT, BUT IMPORTANTLY, ALSO TO ELUCIDATE THE MOLECULAR BIOLOGY BEHIND THE PARASITE RESPONSE TO THOSE PLANTS UNDER WNT. THIS GOES BEYOND MERELY IDENTIFYING RELEVANT HOST GENES, IT ALLOWS US TO UNDERSTAND THE MECHANISMS BY WHICH THOSE GENES ALTER THE NEMATODE BIOLOGY. UNDERSTANDING THE NEMATODE IN ADDITION TO THE PLANT PAVES THE WAY TOWARDS TARGETING THE PARASITE DIRECTLY.