**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** RALSTONIA SOLANACEARUM (R. SOL) IS ONE OF THE MOST DESTRUCTIVE BACTERIAL PLANT PATHOGENSWORLDWIDE. K60, THE TYPE STRAIN FOR THE SPECIES, IS CONSIDERED A WARM-TEMPERATE STRAIN BECAUSE ITTHRIVES IN THE HOT HUMID CONDITIONS OF THE SOUTHEAST UNITED STATES AND SURVIVES THE COOL WINTERS.K60 HAS A HIGHLY COMPETITIVE ADVANTAGE COMPARED TO GMI1000 AND UW551, TWO STRAINS OF THEPATHOGEN THAT ARE TROPICAL AND COLD TOLERANT, RESPECTIVELY. THE COMPETITIVE FITNESS OF K60 ISCORRELATED TO THE PRODUCTION OF STRAIN-SPECIFIC GROWTH INHIBITORS IDENTIFIED AS RHS-TOXINS.COINCIDENTLY, K60 HAS THE LARGEST NUMBER OF PREDICTED RHS GENES. LITTLE IS KNOWN ABOUT THEGENOMIC PROFILE OF R. SOL STRAINS ENDEMIC TO THE US, MUCH LESS, THE RHS-TOXIN REPERTOIRES IN STRAINSOF THE R. SOL FROM THE US. THE GOALS OF THIS NEW INVESTIGATOR STRENGTHENING SEED GRANT IS TO BUILDTHE GENOTYPIC AND PHENOTYPIC RESOURCES NECESSARY FOR THE HUERTA RESEARCH GROUP TO: 1) INVESTIGATETHE APPLICATION OF NICHE THEORY TO MICROBIAL ECOLOGY USING RHS-TOXINS IN THE MODEL R.SOL-TOMATOPATHOSYSTEM; 2) PROFILE THE PHENOTYPIC AND GENOTYPIC DIVERSITY OF R. SOL STRAINS ENDEMIC TO THE US;3) FACILITATE RESEARCH ON MECHANISMS OF SURVIVAL AND RESILIENCE OF PLANT PATHOGENIC BACTERIA; AND 4)PROVIDE NEW KNOWLEDGE THAT THE HUERTA LAB WILL LEVERAGE TO WRITE LARGER AND MORE COLLABORATIVEGRANTS. TOGETHER, THIS GRANT AND THE RESOURCES GENERATED THROUGH THIS PROJECT WILL ESTABLISH THEHUERTA RESEARCH GROUP AS THE LEADING LAB STUDYING MECHANISMS OF COMPETITION IN BACTERIA-PHYTOBIOME INTERACTIONS AND AS EXPERTS IN NATIVE POPULATIONS OF R. SOL IN THE US.