How do plasmid-borne regulatory genes influence bacterial behaviour in complex communities?
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 set of plasmid-encoded transcriptional regulators that subvert ecologically important phenotypes in the plant-growth promoting bacterium Pseudomonas fluorescens. Plasmid regulators studied to date exert major effects on bacterial fitness and conjugation efficiency. However, the functions of most plasmid regulatory genes, their distribution and abundance in naturally occurring plasmids, and the extent to which plasmid regulators control the spread of genetic material through complex microbial communities are currently unknown.
The project will ultimately lead to a molecular-level understanding of plasmid regulation and its role in controlling plasmid maintenance and HGT in complex microbial communities. Plasmid regulatory genes are widespread among divergent plasmids in a wide range of bacterial hosts, suggesting that these genes may control bacterial lifestyle, evolution and HGT in a range of medical and agricultural settings.
The student will be hosted at the internationally recognized 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.
References
Thompson, C. M. A. et al. Plasmids manipulate bacterial behaviour through translational regulatory crosstalk. (2023) PLoS Biology 21, e3001988. https://doi.org/10.1371/journal.pbio.3001988
Bird, S. M. et al. Compensatory mutations reducing the fitness cost of plasmid carriage occur in plant rhizosphere communities. (2023) FEMS microbiology ecology 99(4), fiad027. https://doi.org/10.1093/femsec/fiad027
JG Malone & CMA Thompson, Mechanisms of Plasmid Behavioral Manipulation (2024) DNA and Cell Biology 43 (3), 105-107. https://doi.org/10.1089/dna.2023.0402
Hall JPJ, et al. Plasmid fitness costs are caused by specific genetic conflicts enabling resolution by compensatory mutation. (2021) PLoS Biology 19(10): e3001225. doi:10.1371/journal.pbio.3001225