Self-funded project: Understanding Ralstonia solanacearum plant pathogen evolution in environmental reservoirs

Applications accepted for either MSc by Research or PhD.

Keywords: Evolutionary ecology, Microbiology, Microbiomes, Plant pathology, Virulence, Phages

Ralstonia solanacearum, is a globally important plant pathogenic bacterium capable of infecting various important crops (potato, tomato, banana and eggplant). It infects plants via roots rapidly spreading throughout the vascular system causing wilting of plants due to excessive production of extracellular polysaccharides that block water fluxes within the plant. The primary source of the pathogen in the UK is river water, where it persists throughout the year by overwintering in the roots of its secondary host plant, Woody Nightshade (Solanum dulcamara). However, very little is known about R. solanacearum life-history evolution in environmental reservoirs. Specifically, we poorly understand how adaptation to its secondary host might shape plant pathogen survival, virulence and life history evolution across natural and agricultural environments.

Objectives: This project will use experimental evolution and genomics to causally test how selection in natural environments could predict R. solanacearum life history evolution, transmission and disease outbreaks. To achieve this, we will:

1) Use comparative genomics to characterize differences in pathogen genotypes derived from environmental reservoirs (rivers), secondary hosts (woody nightshade) and primary hosts (potato) based on the UK strain collection spanning past three decades.

2) Use experimental evolution in vitro (to mimic conditions in environmental reservoirs) and in planta to directly test if pathogen adaptation to environmental reservoirs or secondary host affects its survival and virulence in the primary host (tomato or potato).

3) Identify potential causal drivers (abiotic environment, phage parasites, bacterial interactions, host responses) and underlying mechanisms (genetic changes) behind pathogen adaptation using controlled lab experiments.

The project will combine comparative genomics, experimental evolution, microbial ecology and plant biology. You will take advantage of full genome sequenced pathogen strain collection, use Illumina platform to re-sequence evolved pathogen strains and develop bioinformatics and statistical skills to analyse the data. An ideal candidate will have a background in at least one of the main subject areas (microbiology, community ecology, experimental evolution or plant biology) and willingness to develop skills in the other areas.

The Department of Biology at the University of York is committed to recruiting extraordinary future scientists regardless of age, ethnicity, gender, gender identity, disability, sexual orientation or career pathway to date. We understand that commitment and excellence can be shown in many ways and have built our recruitment process to reflect this. We welcome applicants from all backgrounds, particularly those underrepresented in science, who have curiosity, creativity and a drive to learn new skills.