The Effect of Waterlogging on Disease Resistance in Wheat (CASE), BBSRC SWBio DTP PhD Studentship 2025 Entry at University of Exeter

About:

The BBSRC-funded SWBio DTP involves a partnership of world-renown universities, research institutes and industry, based mainly across the South West and Wales.

This partnership has established international, national and regional scientific networks, and widely recognised research excellence and facilities.

We aim to provide you with outstanding interdisciplinary bioscience research training, underpinned by transformative technologies.

Project Description

Background:

The UK has recently seen increased rainfall and flooding events, with 1991-2020 showing an increase of 14% in winter rainfall compared to 1961-1990, and winter 2023-24 seeing 129% of the 1991-2020 average rainfall. Resultant waterlogging of arable fields can be detrimental to many crops – winter wheat, for example, may suffer up to 70% yield losses. Little is known about how waterlogging impacts disease occurrence and severity. However, shifts in the mycobiome of waterlogged plants towards pathogens, including the key UK wheat pathogen, Zymoseptoria tritici, have been reported. Fusarium diseases are also expected to cause increased yield loss and mycotoxin production.  Moreover, waterlogging-induced hypoxia is known to alter soil pH, affect ROS production in roots, alter plant hormone signalling and perturb the soil microbiome, all of which may have knock-on effects upon plant disease susceptibility and thus disease risk in a wetter future.

This project will investigate the effects of waterlogging on two economically important UK wheat pathogens already known to produce more severe symptoms during wet cropping seasons: Zymoseptoria tritici (Zt) and Fusarium graminearum (Fg).  You will also work with industrial partner, Agrii, to learn how better to apply your research in the field.

Questions and Methodologies:

1. Does soil waterlogging affect survival, reproduction and virulence of Fg and Zt? Spore survival, reproduction and virulence on wheat/maize will be tested after incubation in vitro in control vs waterlogged soils or filtered soil solutions for durations comparable to realistic field waterlogging conditions.
2. Does soil waterlogging affect plant defence responses in wheat/maize? Plants exposed to waterlogging will be infected with Fg/Zt and their defence responses – ROS production, defence hormone production gene expression, etc – investigated.
3. Does waterlogging affect disease susceptibility or impact? Disease symptoms and mycotoxin production will be monitored in waterlogged/control plants inoculated with Fg/Zt.
4. Do periods of waterlogging affect soil microbiome and plant health? Field soils will be subjected to waterlogging (or control) conditions and then used to grow wheat. Plant health and disease resistance will be assessed. 16S community analysis of soil microbiomes will be used to determine how waterlogging-induced soil microbiome changes correlate with soil type and plant health.
5. Can data from 1-4 be incorporated into models of UK disease risk under climate change? R-based programming will be used to incorporate the likelihood and impact of waterlogging events into weather-based disease risk models to improve predictions of future disease risk in UK wheat-growing areas.