College of Agriculture & Natural Resources Department of Plant, Soil and Microbial Sciences

My research focuses on bacterial evolution to understand how new pathogenic lineages emerge on plants with the aim to determine the factors that influence disease emergence in the field.

Specifically, we study the role of mobile genetic elements (MGEs) such as plasmids and prophage in bacterial evolution. Mobile genetic elements have their own evolutionary trajectories often distinct from their bacterial host but crucially carry many of the virulence factors that make bacteria pathogenic. On the flip side, bacteria exhibit extensive variation in their competence levels for these elements, and recent research has revealed a multitude of previously unknown immune mechanisms in bacteria that may limit MGE movement. These factors critically influence the potential for pathogen evolution in the field and subsequent disease emergence, but we have a limited understanding of them in non-model organisms.  

We study fundamental aspects of phage and plasmid biology including their ecology, evolution, bacterial host range and gene regulation. We aim to improve our understanding of how these mobile elements interact with the bacteria, move around in bacterial communities and what factors trigger or prevent their transfer. In addition, we will explore how bacterial immunity towards these MGEs impact this and how does compatibility with MGEs impact important bacterial fitness traits. In the crop pathogen Pseudomonas syringae some strains possess multiple prophages and plasmids in their genome, whilst others have none and are recalcitrant to transformation in laboratory conditions. We are interested in how MGEs impact the pathogenic potential of bacterial communities by influencing the movement, regulation, and evolution of virulence genes.

Our program integrates field ecology (sampling, genome sequencing and characterizing bacterial populations) and more fundamental lab-based functional studies on the biology of these mobile elements and their interaction with bacterial hosts. We will use advanced technologies including single-cell techniques, metagenomics, and lineage-tracking.

A deeper understanding of pathogen evolution will aid pathogen tracking and diagnostics, facilitate the prediction of disease emergence and help inform the targeted design of management strategies to mitigate crop losses.

General areas of expertise

Plant-bacteria interactions, molecular plant pathology, population genomics and evolution, bacterial secretion systems and effector biology.

Publications see full list on Google Scholar