Getting to the Root of Infection: Using a Novel Model to Study Innate Immune Responses in Canola

Abstract

Agriculture is important towards the world’s population survival but is challenged by plant pathogens affecting crops worldwide. Canola is one of the world’s most important oilseed crops. Pseudomonas aeruginosa is an opportunistic pathogen with a broad host range and causes disease plants. In this study, we developed a novel root infection model of P. aeruginosa (strain PA14) in canola seedlings to study plant host immunity and bacterial pathogenesis. We showed that P. aeruginosa infection of seedlings caused dramatic weight loss, and that the quorum sensing system (specifically LasR) in P. aeruginosa was required for virulence. We also showed that genes involved in the phytorhomone signalling pathways: salicylic acid, jasmonic acid and ethylene were up regulated throughout the infection. We discovered P. aeruginosa produced coronatine, a jasmonic acid mimic using metabolomics. Finally, we limited the pathogen-induced stress ethylene in canola seedlings, and these plants were less susceptible to P. aeruginosa infection.