TREE FRUIT GROWERS IN THE UNITED STATES NEED EVERY POSSIBLE TOOL TO SUSTAINABLY MAINTAIN A SUPPLY OF NUTRITIOUS FRUIT DESPITE LABOR SHORTAGES, REDUCED LAND AVAILABILITY, AND FREQUENT SEVERE WEATHER EVENTS. THE ABILITY TO BREED TRAITS INTO FRUIT TREES (AND OTHER CROPS) THAT WOULD HELP OVERCOME THESE CHALLENGES IS CRUCIAL TO MAINTAINING FOOD SECURITY IN THIS COUNTRY. ONE APPROACH FOR THIS IS TO BREED TREES WITH SHOOT ARCHITECTURES THAT ARE OPTIMIZED FOR HIGH-DENSITY PLANTINGS, WHICH HAVE BEEN SHOWN TO BE HIGHLY PRODUCTIVE AND COST SAVING. TO INCREASE THE CHANCES THAT SCIENTISTS AND PLANT BREEDERS CAN DO THIS, A GREATER UNDERSTANDING OF THE MOLECULAR BIOLOGY AND GENETICS THAT REGULATE LATERAL SHOOT ORIENTATIONS IN PLANTS IS NEEDED. THE WORK PROPOSED HERE INVESTIGATES THE FUNCTION OF WEEP, A NEWLY IDENTIFIED GENE THAT REGULATES LATERAL BRANCH ORIENTATION IN PEACH TREES. PEACH TREES THAT CONTAIN A NON-FUNCTIONAL WEEP GENE EXHIBIT WEEPING OR DOWNWARD ARCING GROWTH. VERY LITTLE, HOWEVER, IS KNOWN ABOUT WHAT WEEP DOES IN PLANTS AT THE MOLECULAR LEVEL. THIS PROJECT AIMS TO FILL IN THAT GAP. DATA SUCH AS WHERE THE WEEP GENE IS EXPRESSED IN PLANTS AND WHAT PROTEINS THE WEEP PROTEIN INTERACT WITH WILL BE UNCOVERED BY THE PROPOSED EXPERIMENTS. OTHER EXPERIMENTS WILL INVESTIGATE IF WEEP PLAYS A ROLE IN WOOD DEVELOPMENT AS WELL AS THE ABILITY FOR PLANTS TO SENSE AND RESPOND TO LIGHT AND GRAVITY. ULTIMATELY, THIS WORK WILL LAY THE GROUNDWORK FOR BREEDING TREES, AND OTHER CROPS, TO HAVE SHOOT ARCHITECTURES THAT COULD REDUCE THE DEMAND FOR LABOR, AS WELL AS REDUCE PRODUCTION COSTS AND ENVIRONMENTAL IMPACTS.