August 2020
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Research Projects

Plant and microbial systems and diseases

Tackling the world’s biggest killer of rice crops

Major advances in tackling the world’s biggest killer of rice crops and a fungus which kills patients with damaged immune systems have been made by researchers in the School of Biosciences.

Every year the rice blast fungus kills an amount of rice that would feed 60 million people. The fungus that causes rice blast produces a tiny cell that generates more pressure than a car tyre in order to break its way into a rice leaf.

Professor Nick Talbot played a central role in an international team which sequenced the genome of the fungus – one of only three plants in the world so far to have been sequenced. He has also discovered a single gene that appears to be important in allowing the fungus to inject its proteins into the plant’s own cells. This is key to understanding how the disease works since the rice blast proteins overcome the plant’s defences and allow a full scale invasion by the fungus. The Exeter team generated a strain of the rice blast fungus which lacks this protein and was completely unable to cause disease.

It is hoped these discoveries will help develop chemicals to inhibit the disease. More specific, environmentally friendly, compounds to combat rice diseases could result from this BBSRC-funded research.

Understanding the fungus Candida albicans

The fungal pathogen Candida albicans is a particular danger for patients with suppressed immune systems through diseases such as AIDS or because of bone marrow transplants.

Research by Dr Mark Ramsdale has discovered that at certain stages of its development Candida has the ability to kill part of its own cells. A microbe does not normally do this because it only consists of one cell. Further research is being undertaken into exactly how this mechanism allows Candida to flourish and avoid being destroyed by drugs.

A separate but related study in the School of Biosciences, by Dr Steve Bates, is investigating how Candida can change its shape by existing as either a yeast or a fungus. Examination of the cell wall of Candida is particularly important to this work.

How plants can tell bacteria are hostile

Techniques from analytical biochemistry are used to provide snapshots of all of the molecules in the plant at any one time, a new type of procedure called metabolomics.

Studying Arabidopsis, which has the smallest genome of any plant, Professor Murray Grant is looking to identify the chemicals produced by plant pathogens seeking to invade the plant and the defence compounds produced by the plant to defend itself and lead to immunity. Research in these areas is funded by the BBSRC.

How vitamin C is essential for plant growth

Scientists from the University of Exeter and Shimane University in Japan have proved for the first time that vitamin C is essential for plant growth. This discovery could have implications for agriculture and for the production of vitamin C dietary supplements. The study, published in The Plant Journal, describes the newly-identified enzyme GDP-Lgalactose phosphorylase which produces vitamin C in plants.

Mathematical and computational modelling

An important element in systems biology is mathematical modelling; this can play a vital role in bringing together theory and experiment to build a better understanding of a biological system as a whole. Techniques range from data mining, bioinformatics and statistical analysis of data to control theory and stochastic and deterministic models over a wide range of scales. Mathematical modelling often brings not only quantitative insight but also qualitative understanding by relating apparently widely differing problems. At the University of Exeter, mathematical and computational modelling is underway on a number of joint projects between Biosciences and Mathematics.

For more details about our work in this area of research, visit the web pages of the Dynamical Systems and Control research group.

Systems ecology

Ecology and evolutionary biology make intensive use of mathematical models to explain the functioning and dynamics of natural systems. However, natural systems are inherently complex and variable and defy simple predictions. The EXPECT (University of Exeter Predictive Ecology and Conservation Tools) research group works to translate new and established tools from the robust control paradigm of systems engineering into biology to fix this problem.

Professor Stuart Townley and Dr David Hodgson are investigating the signal of genetic variation as we move up from genes to populations to ecosystems. The aim is to help predict the response of biological systems to environmental change.

Using this new systems ecology paradigm, scientists aim to include the effects of noisy environments and competition in their models, and to extend their modelling tools to population genetics, invasion biology and community ecology.