Plant Pathogen Temperature Ecology.

Fungal and oomycete plant pathogens threaten global food security. Crop infection risk is determined in part by temperature and moisture availability, and climate change will alter distributions of both crops and their pathogens. Mathematical models of changing pathogen distributions often implicitly assume that fungi will respond to temperature in the future much as they do now, with no evolution to changing conditions. However, a small amount of existing research has shown that fungi can acclimatize and evolve rapidly to withstand warming. This studentship will combine laboratory experiments and modelling to investigate plant pathogen temperature ecology across various biological scales.

1. What is known about variation in plant pathogen temperature responses? The student will conduct a detailed literature survey of fungal and oomycete plant pathogen temperature responses. Temperature responses will be compared across life cycle stages, and the student will test the hypothesis that in vitro and in planta temperature responses differ. The student will statistically investigate the relationships between temperature tolerance, host specificity, biogeography, and evolutionary relationships among fungi.

2. How will plant pathogen infection risk alter globally under climate change? The student will utilise published infection temperature responses for fungi and oomycetes to investigate whether increasing temperatures will shift infection risk at the global scale. For example, will warming result in increased or decreased disease risk, and if so, where?

3. Can a mechanistic modelling approach be utilised to predict Septoria tritici Blotch (STB) disease risk in space and time? The student will develop an experimentally-parametrised mechanistic model of STB and compare model predictions to observed disease risk.

4. How does Zymoseptoria tritici respond to increasing culture temperatures in the lab? The student will investigate the changes undergone by fungal cultures, assessing molecular and morphological aspects of fungal biology.

5. Is there a trade-off between temperature acclimation and virulence? Evolutionary theory predicts a trade-off between responses to different types of stress. For example, a pathogen responding to high temperature might be less able to infect the host plant. The student will test whether fungal isolates that have been acclimated to grow at higher temperatures retain virulence on wheat.

Through this doctorate the student will receive training in statistical analysis, ecological and evolutionary theory, disease risk modelling, plant pathology, microbiology and fundamental lab skills, as well has making an important contribution to the science of climate change and global food security.