How do plant growth-promoting bacteria colonise the root environment?

MALONE_J21DTP

This project will address a fundamental but poorly understood topic in the field of plant-microbe interaction. Specifically, how do bacteria coordinate their behaviour with primary metabolism and growth? Pseudomonas fluorescens is a widespread, plant-associated bacterium that colonises roots and contributes to plant growth and disease suppression. To successfully colonise the rhizosphere, P. fluorescens must coordinate expression of phenotypes such as motility and biofilm formation with adaptive remodelling of central metabolism to take advantage of available nutrients. While much research has been conducted into both bacterial behaviour and metabolism, we have relatively little understanding of how these two important processes are integrated into a coherent environmental response.

In this project we will use molecular genetics, biochemistry and plant-interaction experiments to investigate a recently-identified regulatory pathway in P. fluorescens that apparently bridges the gap between central metabolism and bacterial behaviour. The student will conduct an in-depth genetic and biochemical analysis of this pathway to determine how it functions, how it is regulated and its target genes within the bacterial cell. They will examine its importance for colonisation of different plant species and cultivars, and for plants growing in different environments. By developing our understanding of the link between metabolism and rhizosphere colonisation phenotypes, this work is likely to have important implications for the identification and/or production of effective biostimulants and biocontrol agents.

The student will be hosted at the internationally recognised John Innes Centre, providing cutting-edge research facilities and a stimulating research and training environment alongside world-leading scientists in the fields of molecular microbiology and plant-microbe interactions. They will be part of a friendly, collaborative research team and will gain excellent training in microbiology, biochemistry and plant-microbe interaction techniques. The combination of transferrable, technical skills associated with the project will make the successful candidate highly employable, in industry or academia.

References:

Control of mRNA translation by dynamic ribosome modification L Grenga, RH Little, G Chandra, SD Woodcock, G Saalbach, RJ Morris and J.G. Malone, PLoS Genetics (2020) 16(6), e1008837

Differential regulation of genes for cyclic-di-GMP metabolism orchestrates adaptive changes during rhizosphere colonization by Pseudomonas fluorescens RH Little, SD Woodcock, R Campilongo, RKY Fung, R Heal… and J.G. Malone, Frontiers Micro (2019) 10, 1089

One ligand, two regulators and three binding sites: How KDPG controls primary carbon metabolism in Pseudomonas R. Campilongo, R. K. Y. Fung… and J.G. Malone, PLoS Genetics (2017) 13(6), e1006839