PhD Transfer Seminar – Claire Breit-McNally (Guttman/Desveaux Lab)

The bacterial phytopathogen Pseudomonas syringae can infect a wide array of plants, including the model plant Arabidopsis thaliana and its agronomically important relatives in the Brassicaceae family. P. syringae possesses a type III secretion system, through which it injects type III secreted effectors (T3SEs) directly into plant cells, where they contribute to bacterial virulence. In response, plant nucleotide-binding leucine rich repeat proteins (NLRs) can recognize T3SEs and mount effector-triggered immunity (ETI). Our labs have developed the Pseudomonas syringae type III effector compendium (PsyTEC), a collection of over 500P. syringae T3SEs from across this diverse pathogen species, and used this collection to screen for ETI elicitors in A. thaliana. While we have gained a deeper understanding of the immune landscape at a species level, my proposed research will expand this exploration to the family level by investigating the prevalence of ETI in other members of Brassicaceae. Towards this goal, I will screen through the diversity of effectors in PsyTEC on two brassicaceous species, Brassica napus (canola) and Camelina sativa (false flax), to identify novel ETI responses. I will then determine whether the NLRs responsible for T3SE recognition in A. thalianaare conserved in B. napus and C. sativa. Finally, I will screen through ETI-eliciting T3SEs in several other important brassicaceous species to explore the patterns of ETI elicitation across the family. Identifying ETI responses in brassicaceous species will provide a resource that can be used to develop crop protection strategies against economically devastating pathogens.