MSc Exit Seminar – Jessica Schembri (Desveaux/Guttman labs)

MSc Exit Seminar

Tuesday September 22nd, 9:30 am – Earth Sciences Centre, Rm. 3087

Jessica Schembri (Desveaux/Guttman labs)

 “Experimental evolution of Pseudomonas syringae pathovar phaseolicola 1448A in the non-host plant Arabidopsis thaliana“

Abstract

Plants use their innate immune system to recognize conserved molecular elicitors of microbes, known as pathogen associated molecular patterns, to contain most microbial infections. Successful microbes may evolve to overcome resistance by suppressing the immune system or avoiding recognition. In plant-pathogen systems, microbes that are not able to overcome the innate immune response are said to have non-host interactions. For example, in the model organism Arabidopsis thaliana Col-0, the bacterial phytopathogen Pseudomonas syringae pathovar phaseolicola 1448A (Pph1448A), a bean pathogen, exhibits a non-host resistance response where the bacteria do not increase in frequency but the infection is not cleared by the plant. Here, an experimental evolution approach was used to track the early stages of adaptation of Pph1448A to A. thaliana Col-0. After 30 serial passages, whole genome sequencing was used to identify single nucleotide polymorphisms that may be linked with Pph1448A’s adaptation to a new plant host. Though mutations seem to be accumulating in Pph1448A these mutations cannot yet be associated with any changes in phenotype. With continued passaging of Pph1448A through Col-0, mutations will likely continue to accumulate in Pph1448A that may, in future, be linked with a change in virulence or other phenotypic traits.