LIKE MANY LIVING ORGANISMS, PLANTS CAN GET SICK WITH BACTERIAL, VIRAL, AND FUNGAL INFECTIONS. PLANT DISEASE CAN HAVE MAJOR IMPACTS ON OUR ACCESS TO HEALTHY FOODS LIKE VEGETABLES, FRUITS, AND NUTS AS WELL AS NEGATIVELY IMPACT FARMERS WHO PRODUCE THESE CROPS. TO OVERCOME THE IMPACTS OF PLANT DISEASE, FARMERS NEED IMPROVED STRATEGIES THAT PROTECT CROPS BUT DO NOT AFFECT THE SAFETY OF THE ENVIRONMENT AND CONSUMERS. BACTERIAL PLANT PATHOGENS ARE PARTICUARLY DEVESTATING BECAUSE THEY ARE ABLE TO EVOLVE RESISTANCE TO MANY OF THE MANAGEMENT STRATEGIES AVAIALBLE TO TREAT INFECTIONSSUCH AS ANTIBIOTICS AND COPPER. ONE SUCH PATHOGEN IS XANTHOMONAS ARBORICOLA PV. PRUNI (XAP) WHICHCAUSES BACTERIAL SPOT ON PEACHAND CAN BE DEVESTATING TO PEACH GROWERS WHEN RESISTANCE EMERGES IN DISEASE CAUSING BATERIAL POPULATIONS. BACTERIAL PATHOGENS ARE NOT ALONE IN THE PLANT, HOWEVER; THEY ARE CONSTANTLY INTERACTING WITH OTHER MICROBES PRESENT ON AND WITHINPLANT TISSUES. ONE SUCH MICROBE ISBACTERIOPHAGE (PHAGE) WHICH ARE VIRUSES THAT INFECTS AND CAN KILL BACTERIAL CELLS. THE INTERACTION BETWEEN BACTERIA AND PHAGE CAN BE IMPORTANT IN DRIVING BACTERIAL EVOLUTION, INCLUDING IMPACTING THE BACTERIA'S ABILITY TO INFECT ITS HOST (THE PLANT). THE AIM OF THIS STUDY IS TO INVESTIGATE THE INTERACTION BETWEEN XAP AND ITS ASSOCIATED PHAGE TO DETEREMINE HOW THISINTERACTION CONTRIBUTES TO PLANT DISEASE AND TO ASSESS WHETHER PHAGE COULD SERVE AS AN ALTERNATIVE TREATMENT FOR BACTERIAL SPOT IN PEACH.TO ADDRESS THE AIM OF THIS PROJECT, WORK WILL BE CONDUCTED IN BOTH THE FIELD AND IN THE LABORATORY FOCUSED ON COLLECTING AND ISOLATING XAP AND ASSOCIATED PHAGE FROM PEACH LEAF TISSUE. FOLLOWING COLLECTION AND ISOLATION, HOST RANGE ASSAYS WILL BE COMPLETED TO DETEREMINE HOW WELL THE PHAGE ARE ABLE TO INFECT THE XAP ISOLATESAND HOW RESISTANT THE XAP ISOLATES ARE THE PHAGE. FINALLY, ANALYSIS WILL BE PERFORMED TO INVESITGATE THE GENETIC COMPONENTS CONTRIBUTING TO THE HOST RANGE OF PHAGE THAT INFECT XAP TO DETERMINE HOW PHAGE MIGHT BE USED AS A TREATMENT FOR XAP INFECTION IN PEACH ORCHARDS. TESTS WILL ALSO BE CONDUCTED USING PEACH SEEDLIGNS TO SEE HOW WELL PHAGE DO AT TREATING XAP INFECTION TO ASESS THEIR POTENTIAL AS A TREATMENT OPTION. ALL OF THE RESULTS OF THIS WORK WILL BE PUBLICLY AVAILABLE THROUGH PUBLISHED ARTICLESAND WILL BE PRESENTED AT CONFERENCES AND SEMINARS TO ENSURE FOLKS IN ALL SECTORS CAN USE THE INFORMATION WHEN MAKING DECISIONS ABOUT MANAGING BACTERIAL DISEASE IN PLANTS.THE ULTIMATE GOAL OF THIS PROJECT IS TO FURTHER OUR UNDERSTANDING OF PHAGE AND HOW THEY MIGHT PLAY A ROLEIN COMBATING ANTIBIOTIC RESISTANCE IN BACTERIAL PATHOGENS. ANTIBIOTIC RESISTANCE IS AN ISSUE IN ALL BACTERIAL INFECTIONS, INCLUDING IN HUMANS. RESERACH ON PHAGE IS NOT LIMITED TO AGRICULTURE; HOWEVER, RESULTS FROM WORK IN PLANTS CAN BE EXTENDED TO OTHER ORGANISMS SUCH AS HUMANS WHEN TRYING TO UNDERSTAND HOW BACTERIA EVOLVEAND HOW THEIR INTEREACTION WITH PHAGE COULD DRIVE THAT EVOLUTION IN THESE DISEASE CAUSING AGENTS. DEVELOPING TREATMENT METHODS FOR BACTEIRAL INFECTIONS THAT DO NOT RELY ON ANTIBIOTICS OR CAN BE USED IN CONJUCTION WITH ANTIBIOTICS IS NECESSARY TO OVERCOME BACTERIAL RESISTANCE INBOTH PLANTAND ANIMAL INFECTIONS. THIS PROJECT WILL CONTRIBUTE TO OUR UNDERSTANDING OF THE COMPLEX INTEREACTION BETWEEN BACTERIA AND PHAGEAND LEAD TO GREATER KNOWLEDGE ON HOW PHAGE MIGHT BE USED IN MANAGING BACTERIAL DISEASES.