Developing phage therapy to reduce plant pathogen virulence

Plant pathogenic bacteria cause considerable losses to food production. This project will develop a novel biocontrol approach to reduce the virulence of plant pathogenic Ralstonia solanacearum bacterium (causative agent of bacterial wilt) using phages - viral parasites of the pathogen. It builds upon previous work (Wang et al. 2019 Nature Biotechnology), where the phage efficacy was found to be based not only on pathogen density reduction but also on evolutionary trade-offs that made phage-resistant mutants less pathogenic. The key aim of this project is to mechanistically understand how phage resistance turns pathogens less virulent.

You will use experimental evolution to create a library of phage-resistant mutants and use sequencing to determine genes linked with phage resistance. Genome scale models developed with https://imean-biotech.com/ will be used to predict the effects of phage resistance mutations on pathogen fitness. Model predictions will be tested experimentally in plant rhizosphere microcosms focusing on:

1. Pathogen metabolic versatility and competitiveness, which are crucial traits in determining pathogen establishment in soil microbiomes.

2. Pathogen ability to compete for space to colonize roots, which is essential for getting access inside the plant.

3. Pathogen ability to evade pattern-triggered or effector-triggered plant immunity within the plant.

This interdisciplinary project will provide a wide range of skills in experimental evolution, genomics, transcriptomics, microscopy, microbiology and plant biology, and will take advantage of pathogen-tomato plant system established in Friman and Harper labs. You will also interact with researchers at Fera Science, which is and international centre of excellence for crop protection and sustainable agriculture