INVESTIGATING THE GENETIC BASIS OF PSEUDOMONAS SYRINGAE ATTACHMENT TO HOST PLANT SURFACES

Many conventional approaches to bacterial plant disease management rely on the application of broad-spectrum antimicrobial compounds. These nonspecific strategies vary in their efficacy of limiting pathogen growth, as well as their risk of off-target effects on beneficial microbiota and environmental health. The effort to produce robust, non-hazardous measures of disease management that specifically target pathogenic microorganisms is thus critical to the development of sustainable agricultural systems. This project focuses on the pathogenesis of Pseudomonas syringae, a bacterial plant pathogen of diverse agricultural plants. In previous studies, we have observed that P. syringae surface attachment is coordinately regulated with the expression of known virulence-associated genes. Attachment of P. syringae to plant host cell surfaces, while likely required for virulence, has not been elucidated on a molecular level. We aim to characterize the genetic basis of P. syringae attachment to host cell surfaces during plant infection. These efforts will identify candidate targets for future plant disease management strategies that aim to mitigate P. syringae disease by blocking bacterial attachment to host cells. In fulfillment of these goals, our objectives are to 1) conduct a high-throughput genetic screen of attachment factors in P. syringae, and 2) assess the impact of attachment-deficient mutations in P. syringae on virulence on host plants. We will perform a phenotypic analysis of P. syringae mutants in attachment genes identified through a forward genetics screen using RB-TnSeq, along with a reverse genetics survey of candidate attachment genes. Completion of this project will provide foundational knowledge of a potentially critical stage of host infection by P. syringae, informing the development of advanced measures of pathogen control.