HIGHLY DISTINGUISHABLE CHARACTERISTICS BETWEEN PLANT SPECIES ARE OFTEN THE RESULT OF DIFFERENCES IN ORGAN SHAPES AND SIZES.LEAVES, FLOWERS, AND FRUITS CAN TAKE ON A WIDE VARIETY OF SHAPES IN THE PLANT KINGDOM, HOWEVER, THE BIOLOGICAL PROCESSES RESPONSIBLE FOR GENERATING THE DIVERSITY OF SHAPE DURING PLANT GROWTH AND DEVELOPMENT REMAIN ELUSIVE. DIFFERENCES IN ORGAN SHAPE CAN ALSO OCCUR WITHIN A SPECIES, SUCH AS THE DIVERSE FRUIT SHAPES OF CULTIVATED TOMATO,SOLANUM LYCOPERSICUM. DIFFERENT SHAPES AND SIZES OF TOMATOES HAVE BEEN SELECTED FOR DURING BREEDING TO GIVE TOMATOES BROAD CULINARY USES THROUGHOUT THE WORLD AND TO FACILITATE MORE EFFICIENT HARVESTING AND PACKAGING OF THE FRUITS. FOR EXAMPLE, LARGE ROUND TOMATOES ARE EXCELLENT FOR SLICES ON SANDWICHES WHILE SMALL ROUND TOMATOES ARE BETTER FOR A SALAD. ELONGATED TOMATOES CAN BE EASILY PACKAGED TOGETHER IN A CAN AND ARE OFTEN USED FOR SAUCES WHILE FLAT TOMATOES CAN BE EASILY STACKED FOR TRANSPORT.RESEARCH HAS DETERMINED THAT MANY ELONGATED TOMATO VARIETIES ARE THE RESULT OF BREEDERS SELECTING FOR MUTATIONS IN TWO OVATE FAMILY PROTEIN (OFP) GENES, OVATE AND OFP20. FURTHERMORE, THE OVARY, WHICH WILL DEVELOP INTO THE TOMATO FRUIT AFTER POLLINATION, IS ALSO ELONGATED BY MUTATIONS IN THESE TWO GENES. THIS RESULT INDICATES THAT THESE GENES CONTROLLING ELONGATED FRUIT SHAPE ARE FUNCTIONING IN THE GROWING OVARY DURING FLOWER DEVELOPMENT.THIS PROJECT AIMS TO UNDERSTAND THE MOLECULAR MECHANISMS THAT ARE REGULATED BY THESE TWO OFP GENES AND TO DETERMINE HOW LOSS OF THESE GENES RESULTS IN ELONGATED OVARIES AND FRUITS. THIS PROJECT WILL INVESTIGATE OFP PROTEIN INTERACTIONS, SUBCELLULAR LOCALIZATION, AND THE ORIENTATION OF CELL DIVISIONS DURING TOMATO FLOWER DEVELOPMENT TO DETERMINE POTENTIAL MOLECULAR MECHANISMS OFPS MAY REGULATE TO CONTROL FRUIT SHAPE.IN ADDITIONAL TO THEIR ROLE IN TOMATO FRUIT SHAPE, OFP GENES HAVE BEEN IMPLICATED IN SHAPE REGULATION OF MULTIPLE ECONOMICALLY IMPORTANT VEGETABLE AND CROP SPECIES INCLUDING POTATO, MELON, AND RICE. TOMATO HAS EXCELLENT GENETIC AND MOLECULAR RESOURCES MAKING IT AN IDEAL SYSTEM TO STUDY HOW FRUIT SHAPE IS REGULATED, AND SINCE OFP GENES ARE PRESENT IN NEARLY ALL LAND PLANTS, DETERMINING THE MOLECULAR MECHANISMS OF OFPS IN TOMATO MAY BROADEN OUR KNOWLEDGE OF HOW ALL PLANT ORGAN SHAPES ARE REGULATED. FURTHERING OUR UNDERSTANDING OF HOW PLANT ORGAN SHAPE IS REGULATED WILL ALLOW FOR BREEDERS AND PRODUCERS TO MODULATE HARVESTABLE ORGAN SHAPES FOR A DESIRED PURPOSE, AND CAN LEAD TO IMPROVEMENTS IN HARVEST EFFICIENCY, PACKAGING, AND CROP YIELD.