MSc Exit Seminar – Sarzana Hossain (Desveaux and Guttman Lab)

Arabidopsis thaliana, a model plant species, serves as a host to study the virulence mechanisms of the phytopathogenic bacterial strain Pseudomonas syringae pv. tomato DC3000 (PtoDC3000). Despite the genetic diversity among Arabidopsis ecotypes, no reports have thoroughly characterized a resistance response against PtoDC3000 in Arabidopsis. 

An Arabidopsis ecotype, Kz-9, was identified as being resistant to PtoDC3000 and demonstrated characteristics consistent with an effector-triggered immune (ETI) response. A screen was undertaken to survey 47 known PtoDC3000 effectors to elucidate the ETI-elicitor in Kz-9. Two candidate effectors were identified: hopI1i and avrE1f. However, a PtoDC3000∆hopI1i mutant did not grow significantly different than wild-type PtoDC3000 in Kz-9, suggesting that AvrE1f or another protein is functioning redundantly with HopI1 to trigger ETI. 

Next-generation mapping highlighted a 1.365 Mbp region of the Kz-9 genome that potentially correlates with resistance to PtoDC3000. This region possesses 18 immunity-associated genes that contain single-nucleotide polymorphisms (SNPs) relative to the Col-0 reference. Further annotation of this genomic region revealed seven unique genes compared to Col-0, including two additional RPS4-like genes. These genes are candidates for downstream forward genetic testing to find the R-gene responsible for PtoDC3000 resistance in Kz-9. 

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Tuesday, December 15^th, 2020 at 12:00pm

https://utoronto.zoom.us/j/88242747007