Bacteria colonize diverse environments, and the various traits that allow them to survive in these different environments are of wide ecological, medical and agricultural relevance. There is thus considerable interest in determining the genetic changes that allow specific strains to flourish in some environments while perishing in others. This project will identify the genes that allow the plant bacterial pathogen Pseudomonas syringae to spread in different environments. The proposed study pairs the comparison of bacterial genomes with comparative functional genetics to identify the specific genes that render P. syringae strains acute pathogens in crop populations and natural plant populations and allow P. syringae to proliferate in soil. An understanding of the genetic changes that allow bacteria to survive in different environments has important implications because slight genetic changes in a bacterial strain can result in the decimation of entire plant populations or the death of a patient. The cross-disciplinary nature of the project supports the training of undergraduate and graduate students. The project includes outreach and education of K-12 students, including students from underrepresented groups.