THIS PROJECT AIMS TO USE A SYSTEMS-LEVEL APPROACH TO UNDERSTAND THE MECHANISM(S) UNDERLYING DISEASES CAUSED BY TWO PATHOGENS IN POTATO: THE SOIL BORNE SPONGOSPORA SUBTERRANEA F. SP. SUBTERRANEA (SSS), A PLASMODIOPHORID (PROTIST) PARASITE, AND POTATO MOP-TOP VIRUS (PMTV), WHICH IS VECTORED BY SSS. SSS INFECTION RESULTS IN POWDERY SCAB DISEASE, WHICH FORMS LESIONS AND EVENTUALLY PUSTULES ON THE EPIDERMIS OF POTATO TUBERS. SSS IS ENDEMIC TO MOST OF THE POTATO PRODUCTION AREAS IN THE U.S. INCLUDING THE PACIFIC NORTHWESTERN (PNW) STATES OF IDAHO, OREGON AND WASHINGTON. PNW PRODUCES MORE THAN 50% OF THE NATION'S POTATOES. WHEREAS POWDERY SCAB AFFECTS THE EPIDERMIS, SECONDARY INFECTION WITH PMTV RESULTS IN INTERNAL TUBER NECROSIS. DAMAGE CAUSED BY SSS AND PMTV RENDERS POTATO TUBERS UNMARKETABLE DUE TO THEIR SCABBED APPEARANCE AND NECROTIC FLESH. DAMAGED SEED TUBERS CAN ALSO BE REJECTED TO AVOID INFESTATION OF CLEAN FIELDS, CAUSING ANOTHER ECONOMIC STRESS. DESPITE MUCH RESEARCH EFFORT, EFFECTIVE FUNGICIDES OR FUMIGATION TREATMENTS FOR POWDERY SCAB DO NOT EXIST, AND CONTROL OF SSS WOULD ALSO REDUCE PMTV. THUS, THERE IS A CLEAR NEED FOR THE DEVELOPMENT OF NOVEL PATHOGEN MANAGEMENT STRATEGIES FOR THIS PEST COMPLEX. OUR LONG-TERM GOAL IS TO UNDERSTAND THE MECHANISM OF PATHOGENESIS UNDERLYING SSS AND PMTV INFECTION TO DEVELOP CRITICALLY NEEDED DISEASE MANAGEMENT STRATEGIES. A MAJOR OBJECTIVE TOWARD THAT GOAL IS UNRAVELING OF THE MOLECULAR MECHANISMS UNDERLYING THE MUTUALISTIC AND ANTAGONISTIC INTERACTIONS AMONG THE HOST PLANT, THE VIRUS, AND THE PROTIST PATHOGEN. WE HYPOTHESIZE THAT THERE IS A UNIQUE GENE REGULATORY NETWORK THAT COORDINATES EACH OF THE TWO KEY PHASES IN THIS SYSTEM: I) WHEN PMTV RESIDES WITHIN THE RESTING SPORE OF THE SSS (MUTUALISM); AND II) WHEN PMTV INFECTS THE POTATO ROOTS ALONG WITH SSS AND CAUSES DISEASE (ANTAGONISM). USING A SYSTEMS-LEVEL ANALYSIS WILL ALLOW US TO IDENTIFY CHANGES IN THOSE NETWORKS OVER TIME, SUCH THAT WE CAN CIRCUMSCRIBE GENE SETS OF MAJOR IMPORTANCE THAT UNDERLIE DISEASE SUSCEPTIBILITY, RESISTANCE AND MUTUALISM. WE PROPOSE TWO OBJECTIVES: (1) INVESTIGATE THE ANTAGONISTIC INTERACTIONS AMONG VIRUS, VECTOR AND HOST; AND (2) ELUCIDATE THE MUTUALISTIC INTERACTION BETWEEN SSS AND PMTV.PROPOSED RESEARCH IS SIGNIFICANT BECAUSE IT WILL EXPLORE A POORLY UNDERSTOOD, YET ECONOMICALLY IMPORTANT, PLANT-PROTIST-VIRUS PATHOSYSTEM. THIS PROJECT WILL BUILD A NEW MODEL SYSTEM FOR UNDERSTANDING PLANT-PROTIST-VIRUS INTERACTIONS, AND ADVANCES OUR KNOWLEDGE TO PROVIDE A PREDICTIVE PATHOGENIC MODEL FOR PLANT PROTECTION. WE EXPECT TO DEVELOP NOVEL APPROACHES FOR DATA INTEGRATION THAT FACILITATE SYSTEMS-LEVEL ANALYSIS AS WE COMBINE TRANSCRIPTOMIC AND REGULATORY APPROACHES TO IDENTIFY KEY GENE EXPRESSION MODULES. THIS KNOWLEDGE WILL LIKELY LEAD TO NOVEL INSIGHTS REGARDING HOW THE PROTIST FACILITATES VIRUS TRANSMISSION THROUGH A MUTUALISTIC INTERACTION. LASTLY, WE EXPECT THAT KNOWLEDGE GAINED COULD LEAD TO THE DEVELOPMENT OF IMPROVED CONTROL STRATEGIES FOR THE POWDERY SCAB DISEASE.THIS PROJECT WILL HAVE POTENTIALLY SIGNIFICANT ECONOMIC, ENVIRONMENTAL, AND SOCIAL BENEFITS. MANAGEMENT OF THE POWDERY SCAB DISEASE RELIES HEAVILY ON FUNGICIDES AND SOIL FUMIGATIONS (COSTING ABOUT $70.00 PER ACRE) THAT ARE ONLY PARTIALLY EFFECTIVE, ARE EXPENSIVE, AND RISKY TO FIELD WORKERS AND THE ENVIRONMENT. THIS PROPOSED WORK WILL CONTRIBUTE TOWARD IMPROVED CONTROL STRATEGIES FOR POWDERY SCAB THROUGH DETERMINING THE MOLECULAR MECHANISMS OF MUTUALISTIC AND ANTAGONISTIC INTERACTIONS AMONG THREE ORGANISMS. SUCH KNOWLEDGE WILL HELP IDENTIFY POTENTIAL MOLECULAR TARGETS TO ENGINEER DISEASE RESISTANCE INTO POTATO AND ALSO OTHER CROPS THAT SUFFER FROM SIMILAR PATHOSYSTEMS. THESE OUTCOMES WOULD BE USEFUL IN DEVELOPING ECO-FRIENDLY AND DURABLE CONTROL OPTIONS FOR DISEASES THAT CURRENTLY RELY ENTIRELY ON CHEMICAL CONTROL MEASURES. IN ADDITION, THE PROJECT WILL INTEGRATE RESEARCH AND EDUCATION THROUGH STUDENT PARTICIPATION IN A VARIETY OF WAYS. ONE PHD STUDENT AND TWO POST-DOCTORAL FELLOWS WILL BE TRAINED IN PLANT GENOMICS, MOLECULAR BIOLOGY, BIOINFORMATICS, AND VIROLOGY. SEVERAL UNDERGRADUATES WILL ALSO PARTICIPATE IN THE PROJECT. A STRONG EMPHASIS WILL BE PLACED ON RECRUITMENT AND TRAINING OF UNDERREPRESENTED GROUPS. STUDENTS' RESEARCH PROJECTS WILL ENCOMPASS THE DEVELOPMENT OF GENETIC CONSTRUCTS, PHENOTYPE ANALYSIS, AS WELL AS BIOINFORMATICS. THIS EXPOSURE WILL OFFER STUDENTS AN EMPOWERING AND EDUCATIONAL GLIMPSE INTO SCIENTIFIC RESEARCH AND PREPARE THEM FOR FUTURE CAREERS IN AGRICULTURAL SCIENCE. THUS, THE PROPOSED PROJECT INTEGRATES RESEARCH AND EDUCATION TO ACHIEVE BENEFICIAL RESULTS FOR EDUCATION, AGRICULTURE, AND THE ENVIRONMENT.