** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** AS SEEDS IMBIBE WATER, THEY RELEASE NUTRIENT-RICH EXUDATES INTO THE 5-10 MM OF SOIL TERMED THE SPERMOSPHERE, WHICH FUELS THE INITIAL INTERACTIONS BETWEEN SOIL AND SEED MICROBES RESULTING IN LIFE OR DEATH FOR THE SEEDLING IN 12-24 HOURS.THE LONG-TERM GOAL OF THIS RESEARCH PROJECT IS TO IMPROVE KNOWLEDGE OF THE FUNCTION OF THE SPERMOSPHERE MICROBIOME TO IMPROVE PLANT DISEASE OUTCOMES. THIS GOAL WILL BE ACCOMPLISHED THROUGH THREE OBJECTIVES USING SOYBEAN AS A MODEL CROP: 1) SELECTION OF SPERMOSPHERE TAXA AND FUNCTIONS, 2) SOIL STEAMING EFFECT ON THE SPERMOSPHERE AND RHIZOSPHERE, AND 3) ROLE OF FUNGAL SECONDARY METABOLITES ON THE SPERMOSPHERE. SHOT-GUN METAGENOMICS OF THE SPERMOSPHERE SAMPLED ACROSS SOILS WILL DETERMINE THE SELECTED SPERMOSPHERE MICROBES AND IF TAXONOMIC DIFFERENCES CONVERGE TO SELECTED FUNCTIONS. SOIL STEAMING WILL LIMIT THE SOIL AS A SOURCE AND FOCUS ON THE TRANSMISSION OF SEED TO SPERMOSPHERE TO RHIZOSPHERE TO PLANT HEALTH. LASTLY, WE WILL USE CRISPR/CAS9 TO KNOCK OUT FUSARIUM VANETTENII SECONDARY METABOLITES AND DETERMINE HOW SPECIFIC FUNGAL GENES ALTER THE ASSEMBLY OF THE SPERMOSPHERE MICROBIOME. WE WILL COMBINE MICROBIOME ANALYSIS WITH MEASUREMENTS OF BIOMASS AND PHOTOSYNTHETIC EFFICIENCY. THESE PLANS ALIGN WITH THE AGRICULTURAL MICROBIOMES IN PLANT SYSTEMS AND NATURAL RESOURCES BY CHARACTERIZING THE MOLECULAR MECHANISMS AND SIGNAL EXCHANGE INVOLVED IN MICROBIOME ASSEMBLY. THESE OBJECTIVES WILL CONTRIBUTE TO AN UNPRECEDENTED ADVANCEMENT IN KNOWLEDGE OF THE MICROBIOME THAT LEADS TO ACTIONABLE TARGETS FOR PATHOGEN CONTROL AND ROBUST CROP GROWTH.