How do plants sense Zymoseptoria tritici effector proteins?

Plant pathogens pose major challenges to crop production and food security. How we protect plants from their most damaging pathogens is therefore vital to a future of sustainable agriculture. The Kettles laboratory combines molecular biology and protein biochemistry with computational approaches to study what makes bacterial and fungal phytopathogens so adept at causing disease. We also investigate the function of the plant innate immune system and how this could be enhanced to prevent infections.

The hemibiotrophic fungus Zymoseptoria tritici is the causative agent of septoria tritici blotch (STB) disease. It is found on wheat crops around the world and is particularly severe in maritime climates such as the UK and western Europe. Protection of wheat from Z. tritici relies heavily on fungicide application and improving wheat genetic resistance. However, Z. tritci isolates have rapidly overcome these protection strategies and so novel means of crop protection are urgently required.

Successful pathogens secrete effector proteins during plant colonisation. Effectors are highly diverse, often uncharacterised proteins that function to dampen immunity or disrupt plant cellular function. Recent work has revealed that some Z. tritici effectors are differentially recognised between the natural host plant (wheat) and non-host plants that are not susceptible to this pathogen (Kettles et al. 2017). In addition, some effectors may also influence interactions with other microbes in the environment (Kettles et al. 2018). This project will focus on understanding the molecular mechanisms that allow a group of previously described Z. tritici effector proteins to be recognised in some plants but not others, and how this contributes towards plant immunity. Our hypothesis is that differential recognition of effectors contributes to the process of non-host disease resistance in plants. The project will primarily investigate; (1) the functions of Z. tritici effectors during interaction with both host and non-host plants, and (2) the molecular factors that determine whether effectors are recognised by the plant immune system. In a final objective, the project will test whether synthetic effector receptors can be designed to enhance plant disease resistance.

The student will gain significant experience of methods relating to plant pathology, recombinant protein expression, virus-induced gene silencing (VIGS), RNAseq, protein biochemistry and fungal mutagenesis. Applications are encouraged from graduates in the following disciplines: plant biology, microbiology, biochemistry and bioinformatics.
For informal enquiries, please contact Dr Graeme Kettles ([email protected]). Please state the project title on any email enquiries.