**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** WE SEEK TO UNDERSTAND THE CHEMICAL MECHANISMS BY WHICH PLANTS ENGAGE IN BENEFICIAL MICROBIAL RELATIONSHIPS AND DEFEND AGAINST PATHOGENS, WHICH WILL BENEFIT FOOD QUALITY, YIELD, AND SUPPLY. THE FRONTIER OF ROOT DEFENSE AGAINST PATHOGENS IS LED BY PLANT ROOT BORDER CELLS, WHICH ARE POISED AT THE INTERFACE BETWEEN ROOT AND SOIL. BORDER CELLS ARE A SPECIALIZED CELL TYPE LOCATED AT THE ROOT TIPS OF MOST PLANT SPECIES. THEY VIOLATE TRADITIONAL KNOWLEDGE OF PLANT CELLS IN THAT THEY ARE NOT FORMALLY ATTACHED TO THE PLANT ROOT TIP. INSTEAD, BORDER CELLS ADHERE TO THE ROOT TIP THROUGH A COMPLEX ASSORTMENT OF SECRETIONS. SINCE THEY ARE NOT PROPERLY ATTACHED TO THE ROOT, BORDER CELLS CAN BE REMOVED UPON EXPOSURE TO WATER, AND THEY ARE RAPIDLY REPLACED WITHIN 24 HOURS AFTER INITIAL REMOVAL TO BE HELD IN PLACE ONCE AGAIN BY THEIR SECRETIONS. BORDER CELL SECRETIONS INCLUDE DNA (WHICH IS HIGHLY UNIQUE AS A SECRETION), PROTEINS, MUCILAGE, AND METABOLITES. IN GENERAL, METABOLITES ENCOMPASS A WIDE RANGEOF COMPOUNDS NECESSARY FOR LIFE AND GROWTH. RECOGNIZABLE METABOLITES TO THE GENERAL PUBLIC MIGHT INCLUDE GLUCOSE AND CAFFEINE, BUT THERE ARE THOUSANDS OF OTHERS. WHILE HELPING TO ADHERE BORDER CELLS TO THE ROOT TIP, THESE SECRETIONS ALSO FORM A STICKY TRAP THAT CAPTURES MICROBES, PREVENTING PATHOGENS FROM ACCESSING THE ROOT TIP AND PREVENTING INFECTION. FURTHERMORE, THE VARIOUS PROTEINS AND KNOWN METABOLITES POSSESS BENEFICIAL AND/OR CHEMICALLY PROTECTIVE, DEFENSE RELATED PROPERTIES. COLLECTIVELY, BORDER CELLS ARE ESSENTIAL IN PROTECTION OF THE ROOT TIP (WHICH IS THE BASE OF ALL ROOT GROWTH, FRAGILE, AND SUSCEPTIBLE TO LETHAL INFECTION) FROM INVADING PATHOGENIC MICROBES.WE HYPOTHESIZE THAT BORDER CELLS DIRECTLY MANIPULATE THE SURROUNDING SOIL TO CREATE A FAVORABLE LOCAL CHEMICAL ENVIRONMENT FOR ROOT/PLANT HEALTH THROUGH SECRETION OF METABOLITES. IN THIS, OUR PRIMARY GOALS ARE TO ESTABLISH THE IDENTITIES OF BORDER CELL SECRETED/RELEASED METABOLITES AND THEIR SECRETORY PATHWAYS. WHILE THE METABOLITES ARISING FROM BOTH BORDER CELLS AND THE ROOT TIP HAVE BEEN STUDIED PREVIOUSLY, THE SPECIFIC SECRETIONS ARISING FROM BORDER CELLS REMAINS UNKNOWN. IN OUR STUDY, WE AIM TO ISOLATE BORDER CELLS FROM THE ROOT TIPS OF MEDICAGO TRUNCATULA (A RELATIVE TO ALFALFA) IN CUSTOM BIOREACTORS. AFTER ISOLATION, WE WILL HARVEST THE SECRETIONS ARISING SPECIFICALLY FROM BORDER CELLS TO IDENTIFY COMPOUNDS INVOLVED IN BENEFICIAL OR DEFENSE-RELATED FUNCTIONS. FURTHERMORE, WE WILL ALSO STUDY THE SPECIFIC MECHANISMS BY WHICH BORDER CELLS SECRETE THESE COMPOUNDS. ULTIMATELY, OUR STUDIES WILL GENERATE KNOWLEDGE EMPOWERING METHODS TO CREATE HEALTHIER PLANTS WITH HIGHER FOOD YIELDS.