PhD Transfer Exam

Kathryn McTavish (Guttman lab)

“Phylogenetic and Functional Analysis of Pseudomonas syringae Host Adaption to Coffee”

Abstract

Bacterial Blight of Coffee greatly threatens coffee production worldwide. Two lineages of the causal agent of this disease, Pseudomonas syringae pv. garcae, have been isolated from Brazilian Coffea arabica trees. In an attempt to unravel potential genetic attributes associated with this disease, we isolated, sequenced and performed comparative genomics analyses on 56 P. syringae isolates sampled from diseased coffee plants. These analyses have provided us with a list of genes strongly associated with the ability to infect coffee. Furthermore, a plasmid is hypothesized to carry the primary virulence genes in both lineages, suggesting that plasmid exchanges among isolates from distinct lineages may have contributed to coffee adaptation. My project seeks to identify the genetic and molecular basis of P. syringae coffee pathogenicity, focussing on the type III secretion system effector repertoire required for infection. I will first assess the contribution of the identified genes to coffee pathogenicity. I will also screen a representative subset of P. syringae strains, which will provide information regarding host specificity across the species complex as a whole. Combining phylogenetic analysis with host range testing will contribute to understanding the evolution of coffee pathogenic bacteria and further our understanding of P. syringae host range to predict future host adaption events.

Wednesday, December 11, 2019 at 12:10 pm –  Ramsay Wright Building, Room 432