** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** CELLS CAN COMMUNICATE USING CHEMICAL SIGNALS, OR LIGANDS. WITHIN THE CELL MEMBRANE THERE ARE PROTEIN RECEPTORS THAT BIND THESE LIGANDS. ONCE THE RECEPTOR BINDS THE LIGAND, A SIGNALING CASCADE IS STARTED USING SECONDARY MESSENGERS. ONE CLASS OF THESE SECONDARY MESSENGERS IS HETEROTRIMERIC G PROTEINS WHICH CAN MEDIATE SIGNALING BETWEEN THE CELL SURFACE AND CELL INTERIOR. G PROTEINS CONSIST OF GΑ, GΒ, AND GΓ SUBUNITS. RICE PLANTS WITH MUTATIONS IN THE GΑ SUBUNIT, RGA1/D1, HAVE INCREASED DROUGHT RESISTANCE. HOWEVER, THE BIOLOGICAL BASIS FOR THIS IS UNKNOWN. DUE TO CLIMATE CHANGE, DROUGHT IS AN EMERGING PERVASIVE PROBLEM IMPEDING RICE PRODUCTION. IN RICE, MILD DROUGHT CAN REDUCE YIELD BY 17%, AND SEVERE DROUGHT CAN REDUCE YIELD UP TO 65%. THEREFORE, IDENTIFYING THE REGULATION AND ROLE OF RGA1 IN DROUGHT STRESS WILL PROVIDE A BETTER UNDERSTANDING OF THE MECHANISMS INVOLVED IN RICE DROUGHT RESPONSES. A PROMOTER IS ONE REGULATOR OF GENE EXPRESSION, AND CONTAINS SHORT CONSERVED SEQUENCES CALLED CIS-ACTING REGULATORY ELEMENTS (CRES) THAT BIND REGULATORY PROTEINS CALLED TRANSCRIPTION FACTORS. TO STUDY WHICH CRES ARE INVOLVED IN RGA1 GENE EXPRESSION DURING DROUGHT, THE RGA1 PROMOTER WILL BE DIVIDED INTO DIFFERENT SEGMENTS AND CHANGES IN PLANT DEVELOPMENT AND DROUGHT STRESS RESPONSES WILL BE MEASURED. IN ADDITION, THIS RESEARCH WILL UTILIZE A CHEMICAL TAGGING APPROACH TO IDENTIFY WHICH PROTEINS RGA1 INTERACTS WITH DURING DROUGHT. TOGETHER THESE DATA CAN IDENTIFY POSSIBLE TARGETS FOR IMPROVING DROUGHT TOLERANCE IN RICE. IMPROVED DROUGHT TOLERANCE WILL LEAD TO REDUCED YIELD LOSS DURING PERIODS OF DROUGHT, THEREBY PREVENTING ECONOMIC LOSS AND FOOD SHORTAGES.

The Pennsylvania State University

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