**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** AS THE GLOBAL POPULATION CONTINUES TO GROW, SO DO OUR NEEDS FOR RESOURCES AND FOOD. THE CEREAL CROP RICE PROVIDES ~30% OF THE CALORIES CONSUMED BY HUMANS GLOBALLY. INCREASING RICE ROBUSTNESS AND YIELD (NUMBER OF GRAINS) WOULD HELP TO MEET THESE GLOBAL FOOD NEEDS. PREVIOUS WORK HAS DEMONSTRATED THAT HIGHER LEVELS OF THE PLANT HORMONE CYTOKININ POSITIVELY INFLUENCE GRAIN PRODUCTION IN RICE, SPECIFICALLY BY INCREASING THE NUMBER OF GRAINS PRODUCED BY EACH PANICLE (INFLORESCENCE). THIS IS A VERY PROMISING LEAD TO FOLLOW, AS MANIPULATION OF THIS PROCESS WOULD PRODUCE HIGH-YIELD RICE. HOWEVER, THE REGULATORY MECHANISM BEHIND THIS PHENOMENON IS NOT YET UNDERSTOOD. BY USING THE POPULAR GENE EDITING SYSTEM CRISPR/CAS9, WE HAVE DEVELOPED AN EXTENSIVE COLLECTION OF RICE LINES WITH PRECISE EDITS DISRUPTING A GROUP OF GENES (CALLED THE TYPE-A RESPONSE REGULATORS) KNOWN TO INHIBIT CYTOKININ RESPONSE--MEANING THESE PLANTS SHOULD HAVE HEIGHTED RESPONSE TO CYTOKININ AND INCREASED GRAIN YIELD. FURTHER,BY USING TRADITIONAL BREEDING TECHNIQUES, WE ARE CROSSING THESE LINES TO WILD TYPE PLANTS AND SELECT THOSE INDIVIDUALS THAT RETAIN THE PRECISE MUTATION(S) OF INTEREST BUT LACK TRANSGENIC MATERIAL. WE ARE STUDYING THESE LINES CLOSELY TO IDENTIFY PLANTS WITH BETTER PERFORMANCE BY MEASURING IMPORTANT TRAITS SUCH AS PLANT SIZE, NUMBER OF DAYS TO FLOWER, NUMBER OF PANICLES/INFLORESCENCES PER PLANT, ABILITY TO EFFICIENTLY HARVEST LIGHT ENERGY (PHOTOSYNTHESIS), AND GRAIN YIELD. USING THESE DATA, WE WILL IDENTIFY THE MOST PRODUCTIVE LINES AND STUDY GENE EXPRESSION VIA RNA-SEQUENCING IN THEIR INFLORESCENCE MERISTEMS--THE DEVELOPMENTAL TISSUE THAT GIVES RISE TO THE MATURE PANICLE AND, ULTIMATELY, GRAINS--AS COMPARED TO WILD TYPE (UN-EDITED) PLANTS. FROM THESE DATA, GENES TARGETED BY THE TYPE-A RRS WILL BE IDENTIFIED AND STUDIED FURTHER; THUS, SHEDDING LIGHT ON THE MECHANISM OF TYPE-A RR ACTION. OVERALL, THIS WORK WILL BRING US MUCH CLOSER TO ESTABLISHING HIGHLY PRODUCTIVE FIELD-READY RICE LINES.