RICE IS LIFE--A STAPLE FOOD FOR MORE THAN HALF OF HUMANITY. GLOBALLY, RICE PRODUCTION MUST INCREASE IN ACCORDANCE WITH THE POPULATION GROWTH OF DEVELOPING NATIONS TO ENSURE FOOD SECURITY FOR NINE BILLION PEOPLE BY 2050 IN THE FACE OF INCREASING EXTREME WEATHER EVENTS, INCLUDING HEAVY PRECIPITATION. FLOODING IS A FREQUENT NATURAL DISASTER, IN 2015 ALONE, CROP DAMAGE FROM FLOODS AMOUNTED TO OVER $471 MILLION IN THE U.S. WHILE THE LOSS IN RICE PRODUCTION DUE TO FLASH FLOODING ALONE EXCEEDS $1 BILLION EACH YEAR IN ASIA. FURTHERMORE, THERE IS EVIDENCE OF AN ASSOCIATION BETWEEN WEATHER VARIABLES, INCLUDING RAINFALL AND REPEATED FLOODS, AND POOR CHILD HEALTH AND DEVELOPMENT DUE TO MALNUTRITION AT THE HOUSEHOLD LEVEL. DEPLOYING HIGH-YIELDING SUBMERGENCE TOLERANT RICE IS ONE OF THE BEST MEASURES TO MITIGATE FLOODING IMPACTS. THE PRIOR IDENTIFICATION OF SUB1 (SUB1A), A SINGLE GENE THAT IMPROVES THE TOLERANCE OF RICE TO SUBMERGENCE HAS BENEFITED MILLIONS OF FARMERS. SUB1 CONFERS TOLERANCE TO SUBMERGENCE VIA A QUIESCENCE STRATEGY, WHERE THE PLANT LIMITS GROWTH UNDER SUBMERGENCE TO CONSERVE ENERGY WHICH HELPS THE PLANT REGROW AFTER DE-SUBMERGENCE. VARIETIES BRED TO POSSESS SUB1 NOW PROVIDE SIGNIFICANT YIELD PRESERVATION IN FARMERS' FIELDS WHEN FLOODING OCCURS DURING THE VEGETATIVE STAGE. HOWEVER, AREAS WITH REPEATED, SEVERE AND PROLONGED FLOODING REQUIRE VARIETIES THAT HAVE HIGHER LEVELS OF SUBMERGENCE TOLERANCE. THIS PROJECT SEEKS NEW TOLERANCE GENES THAT ARE COMPLEMENTARY TO SUB1 TO FURTHER INCREASE YIELDS IN FLOOD-PRONE AREAS. A SECOND MAJOR QUANTITATIVE TRAIT LOCUS THAT HAS THE POTENTIAL TO ENHANCE SUBMERGENCE TOLERANCE, QSUB8.1, HAS BEEN IDENTIFIED FROM A GENETIC MAPPING POPULATION THAT ALREADY POSSESES SUB1. WE PROPOSE TO IDENTIFY THE KEY GENE(S) OF QSUB8.1 AND INVESTIGATE HOW ITS WORKS TO PROVIDE SUBMERGENCE TOLERANCE IN CONJUNCTION WITH SUB1A. THE MAJOR OUTCOME WILL BE KNOWLEDGE OF FUNCTIONAL GENE(S) THAT IMPROVE THE SURVIVAL OF RICE OF A SERIOUS FLOOD. THIS WILL AID IMPROVEMENT OF FLOODING SURVIVAL STRATEGIES TO FLOOD-SENSITIVE CROPS INCLUDING MAIZE AND SOYBEAN.