WE WILL DETERMINE THE INFLUENCE OF MICROORGANISMS ASSOCIATED WITH SALAD CROP (LETTUCE MIZUNA AND TOMATO) IN PLANT GROWTH AND PROTECTION AGAINST PATHOGENESIS UNDER CONDITIONS SIMILAR TO THE ISS BY UTILIZING METAGENOMICS AND METATRANSCRIPTOMIC APPROACHES. LONG-DURATION EXPLORATION IN SPACE HAS EMPHASIZED THE IMPORTANCE OF UNDERSTANDING HOW TO GROW PLANTS UNDER MICROGRAVITY SO AS TO SUPPLY CREWS WITH A CONTINUOUS SOURCE OF FRESH FOOD AS WELL AS PROVIDE PSYCHOLOGICAL BENEFITS. IN 2015 ZINNIA HYBRIDA GROWN IN THE VEGETABLE PRODUCTION SYSTEM (VEGGIE) ON BOARD THE INTERNATIONAL SPACE STATION (ISS) WAS INFECTED BY AN OPPORTUNISTIC FUNGAL PATHOGEN FUSARIUM OXYSPORUM. THE PATHOGENIC STRAINS OF F. OXYSPORUM CAUSES FUSARIUM WILT WHICH IS LETHAL SWIFT AND CAUSES DISEASES IN NEARLY EVERY AGRICULTURALLY IMPORTANT CROP. IN ADDITION IN IMMUNOCOMPROMISED PATIENTS SUCH AS ASTRONAUTS THIS MULTIHOST PATHOGEN CAN CAUSE INVASIVE FUNGAL INFECTIONS. THEREFORE UNDERSTANDING THE MICROBIAL POPULATION ASSOCIATED WITH PLANT GROWTH AND THE MOLECULAR ASPECTS OF SUPPRESSING MULTIHOST PATHOGENESIS IN SPACEFLIGHT IS NOT ONLY CRUCIAL FOR SUSTAINING THE PRODUCTION OF EDIBLE CROPS IN SPACE BUT ALSO VITAL FOR THE SAFETY OF CREW MEMBERS. THE OBJECTIVE OF THIS GROUND-BASED INVESTIGATION IS TO DEVELOP A REFINED UNDERSTANDING OF THE BASAL PLANT MICROBIOME OF SALAD CROPS GROWN IN PLANT GROWTH CHAMBERS UNDER PREVIOUSLY USED ISS GROWTH CONDITIONS AND ASSESS ITS POTENTIAL FOR PLANT GROWTH ENHANCEMENTS AND HUMAN PATHOGENICITY. DEFINING THE BASAL PLANT MICROBIOME WILL ENABLE US TO UNDERSTAND HOW SPACEFLIGHT CAUSES ALTERATIONS IN PLANT-MICROBIAL INTERACTIONS AND HOW TO UTILIZE IT FOR FUTURE SPACE EXPLORATION EFFORTS. THE LONG-TERM GOAL OF THIS RESEARCH IS TO DEVELOP COUNTERMEASURES BIOTIC OR TRANSGENIC NECESSARY TO ALLOW A SAFE AND SUSTAINABLE HUMAN PRESENCE IN SPACE.