FLOWERING AND SEED GERMINATION ARE TWO CRITICAL DEVELOPMENTAL PHASES IN FLOWERING PLANTS AND REGULATED BY GENETIC FACTORS AND INFLUENCED BY ENVIRONMENTAL CUES ESPECIALLY TEMPERATURES. HIGH TEMPERATURES PROMOTE LETTUCE BOLTING/FLOWERING BUT INHIBIT SEED GERMINATION. INHIBITION OF SEED GERMINATION AND PREMATURE BOLTING UNDER HIGH TEMPERATURE LIMIT LETTUCE PRODUCTION TO NARROW PLANTING AREAS OR GROWING SEASONS IN THE U.S. WHILE ENORMOUS PROGRESS HAS BEEN MADE TO UNDERSTAND THE MOLECULAR BASES CONTROLLING FLOWERING AND SEED GERMINATION, THE MECHANISM UNDERLYING THE TEMPERATURE REGULATION ON BOTH DEVELOPMENTAL PHASES REMAINS TO BE INVESTIGATED. PREVIOUSLY, WE HAVE IDENTIFIED THAT ONE GENE PUTATIVELY REGULATING SEED DORMANCY ALSO INFLUENCES FLOWERING TIME IN LETTUCE. UNDERSTANDING THIS REGULATORY NETWORK IN CONTROLLING BOTH SEED GERMINATION AND FLOWERING TIME WILL BE OF GREAT BENEFIT TO BREEDING HEAT TOLERANT LETTUCE AND EXPANSION OF LETTUCE GROWING AREA. IN THIS PROJECT, WE USE INTEGREATED APPROACHES TO UNDERSTAND HOW THIS GENE INTEGRATE TEMPERATURE SIGNALS TO REGULATE BOTH SEED GERMINATION AND FLOWERING TIME. THIS RESEARCH PROPOSAL WILL EXTEND OUR PREVIOUS FINDINGS AND PROVIDE NOVEL INSIGHTS INTO TEMPERATURE-DEPENDENT MECHANISMS REGULATING SEED THERMOINHIBITION AND FLOWERING, ENABLING US TO DEVELOP NEW LETTUCE VARIETIES ADAPTED TO CHANGING ENVIRONMENTS FOR EXPANSION OF LETTUCE PLANTING AREAS.