SOYBEAN IS ONE OF THE MOST IMPORTANT CROP PLANTS WORLDWIDE AS IT IS A PRIMARY SOURCE OF PROTEIN AND VEGETABLE OIL IN FEED USED TO PRODUCE BEEF, HOGS, AND CHICKENS, AS WELL AS BEING CONSUMED DIRECTLY BY HUMANS. HOWEVER, THERE ARE A VARIETY OF DISEASES AND PESTS THAT JEOPARDIZE OVERALL SOYBEAN HEALTH AND ULTIMATELY DECREASE SOYBEAN YIELDS. ONE OF THE MOST DAMAGING PATHOGENS OF SOYBEAN IN NORTH AMERICA IS THE SOYBEAN CYST NEMATODE (SCN), WHICH INFECTS THE PLANT'S ROOTS. CURRENT METHODS TO PREVENT SOYBEAN CYST NEMATODE INFECTION ONLY PROVIDE LIMITED PROTECTION AND THE OVERUSE OF THESE STRATEGIES HAVE RESULTED IN DECREASED EFFICIENCY AS THE NEMATODES HAVE DEVELOPED WAYS TO OVERCOME THEM. DUE TO THIS, NEW METHODS TO PREVENT SOYBEAN CYST NEMATODE INFECTION ARE IN HIGH DEMAND. WITHOUT NEW MANAGEMENT STRATEGIES, A WIDE ARRAY OF PRODUCTS THAT COME FROM SOYBEAN ARE AT RISK OF BECOMING SCARCE OR UNAVAILABLE. TO DEVELOP NEW METHODS FOR COMBATTING SCN, IT IS IMPORTANT TO UNDERSTAND HOW SCN DEVELOPS AND MAINTAINS INFECTION IN SOYBEAN ROOTS. IT IS WIDELY KNOWN IN THE RESEARCH COMMUNITY THAT SCN DELIVERS SALIVARY SECRETIONS INTO PLANT CELLS. IN THESE SALIVARY SECRETIONS ARE PROTEINS KNOWN AS EFFECTORS. EFFECTOR PROTEINS ARE KNOWN TO HIJACK AND REPROGRAM HOST PLANT CELLS FOR THE PATHOGEN'S BENEFIT. AS THE EFFECTOR PROTEINS SECRETED BY SCN ARE KNOWN TO BE ONE OF THE MOST IMPORTANT ASPECTS OF INFECTION, I HAVE SELECTED 11 UNCHARACTERIZED SCN EFFECTOR PROTEINS WITH THE OVERALL GOAL OF UNDERSTANDING THE SPECIFIC FUNCTIONS OF THESE PROTEINS AS WELL AS IDENTIFYING THE PLANT PATHWAYS THEY DISRUPT. I WILL FIRST BE INVESTIGATING IF THE SCN EFFECTOR PROTEINS INTERFERE WITH PLANT IMMUNE RESPONSES. IF A PROTEIN DOES INTERFERE WITH PLANT IMMUNITY, I WILL THEN IDENTIFY THE SPECIFIC PLANT PROTEIN THAT IT TARGETS. IDENTIFYING THE PLANT PROTEIN(S) TARGETED BY THE EFFECTOR PROTEIN WILL BE THE FIRST STEP TO UNDERSTANDING HOW THE PLANT IS IMPACTED BY THE NEMATODE. AFTER IDENTIFYING THE SCN EFFECTOR PROTEIN TARGETS, I WILL REMOVE THE GENE THAT PRODUCES THE PROTEIN FROM THE PLANT GENOME. THIS WILL BE ACCOMPLISHED USING GENOME EDITING IN SOYBEAN ROOTS. THE ROOTS THAT LACK THE EFFECTOR PROTEIN TARGET WILL BE INFECTED WITH SCN IN THE LABORATORY TO DETERMINE THE ROLE THAT THE PLANT PROTEIN PLAYS IN THE INFECTION PROCESS. IT IS POSSIBLE THAT REMOVING A GENE FROM THE PLANT GENOME WILL DECREASE THE NEMATODE'S VIRULENCE WITHOUT HARMING THE PLANT. RESULTS FROM THIS RESEARCH WILL ESTABLISH AN IMPORTANT FOUNDATION FOR EXPLORING THE PLANT PATHWAYS AND PROTEINS THAT SHOULD BE OF INTEREST WHEN DEVELOPING NEW SOYBEAN VARIETIES THAT ARE RESISTANT TO SCN INFECTION. ADDITIONALLY, THE FINDINGS OF THIS RESEARCH HAVE GREAT POTENTIAL TO PROVIDE INSIGHT INTO HOW OTHER PLANT-PARASITIC NEMATODES ESTABLISH INFECTION. THROUGHOUT THIS PROJECT, I WILL BE MENTORED BY DR. ROGER INNES, A LEADER IN PLANT-PATHOGEN INTERACTIONS, AND DR. THOMAS BAUM, AND EXPERT IN NEMATOLOGY, WHICH WILL ALLOW FOR A DEEP UNDERSTANDING OF THE RELATIONSHIP BETWEEN THE EFFECTOR PROTEINS SECRETED BY SCN AND THE HOST PLANT.TOGETHER, THESE EXPERIMENTS WILL PROVIDE A FOUNDATION OF KNOWLEDGE THAT IS ESSENTIAL FOR DEVELOPING NEW VARIETIES OF SOYBEAN THAT ARE RESISTANT TO SCN, WHICH WILL IMPROVE FOOD SECURITY IN THE USA AND THE WORLD.