** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** THE CIRCADIAN CLOCK IS FUNDAMENTAL TO MANY LIFE FUNCTIONS. THE ABILITY TO COORDINATE DAILY BIOCHEMICAL AND METABOLIC ACTIVITIES BASED ON ENVIRONMENTAL CUES, LIKE TEMPERATURE, IS IMPORTANT TO ALL LIFE. A LESS RECOGNIZED ROLE FOR THE CIRCADIAN CLOCK IS THAT OF REGULATING RESPONSES TO PATHOGEN ATTACK. WITH THE OBSERVED AND EXPECTED CHANGES IN GLOBAL CLIMATE, THERE IS A CRITICAL NEED TO UNDERSTAND THE IMPORTANCE OF THERMOCYCLES IN TERMS OF PLANT GROWTH AND DEVELOPMENT, AND THEIR EFFECTS ON PLANTS RESPONSE TO PATHOGENS. THE MAJOR GOALS OF THIS PROJECT ARE TO IDENTIFY AND QUANTIFY DIFFERENTIAL PLANT RESPONSES TO PATHOGEN ATTACK UNDER NORMAL NIGHT TEMPERATURE (NNT) AND WARMER NIGHT TEMPERATURE (WNT) AND TO DISSECT THE GENETIC ARCHITECTURE IN PLANTS UNDERPINNING BOTH THESE DIFFERENT RESPONSES AND THE SIGNALING THAT OCCURS BETWEEN PLANT HOST AND PATHOGEN. WE WILL USE THE POWERFUL GENETIC TOOLS AVAILABLE IN TOMATO AND ROOT-KNOT NEMATODE (RKN: MELOIDOGYNE HAPLA). OUR APPROACH WILL ENABLE US TO IDENTIFY GENETIC VARIANTS IN PLANTS THAT DISPLAY MORE ROBUST RESPONSES TO INFECTION DURING WNT AND WILL ALSO ENABLE US TO EXPLORE THE BIOLOGICAL BASIS OF THE INTERACTIONS BETWEEN A HOST PLANT, AN IMPORTANT AND AGRICULTURALLY DAMAGING PLANT PATHOGEN, AND ENVIRONMENTAL CHANGES. THIS PROJECT IS FOCUSED ON UNDERSTANDING THE INTERSECTION OF ABIOTIC AND BIOTIC STRESS RESPONSES OF PLANTS.