How do plasmids control plant colonisation by biocontrol bacteria?


Conjugative plasmids play a crucial role in bacterial evolution as drivers of horizontal gene transfer (HGT) and as a source of new genetic information. This project will provide insights into a crucial but largely unstudied aspect of plasmid biology and bacterial decision-making. Specifically, how and why do plasmid-borne regulatory genes influence bacterial behaviour?

In this project the student will use a combination of molecular genetics, biochemistry and plant-interaction experiments to investigate a plasmid-encoded transcriptional regulator, ParQ, which subverts ecologically important phenotypes in the plant-growth promoting bacterium Pseudomonas fluorescens.
While ParQ appears to have major effects on bacterial fitness and plasmid transmission efficiency, the mechanism of ParQ function, how it interacts with the wider bacterial and plasmid signalling network and its influence on plant-host interaction and colonisation are currently unknown.

Ultimately, the project will produce a molecular-level understanding of ParQ function and its role in controlling plasmid maintenance and HGT in bacteria. ParQ homologs are widespread among divergent plasmids in a wide range of bacterial hosts, suggesting that parQ-like genes may control bacterial lifestyle, evolution and HGT in a range of medical and agricultural settings.

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 molecular biology, 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.


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4. Grenga L, Little RH, et al. PLoS Genet. (2020) 16(6):e1008837 5. Jalal ASB, Tran NT, et al. Mol Cell (2021) 81(17) 3623-3636.