My research concerns a fungus, Zymoseptoria tritici, which attacks wheat plants, causing a disease known as Septoria tritici blotch (STB). STB costs the UK around £300 Million per year in lost wheat yields and in the cost of the fungicide used on the crops. Worse, the fungus is beginning to develop resistance to the fungicides that are available to treat it. This means that we need new methods to control the infection. To develop new ways to control Z. tritici, it is necessary to gain a full understanding of the ways in which the fungus interacts with the wheat plant, and how that interaction can be affected by environmental conditions. In previous work, I showed that some isolates of Z. tritici can grow on the leaf surface for around ten days before invading. The amount and duration of leaf surface growth varies between fungal isolates, and also when the same isolate infects different wheat varieties. If the particular wheat variety is resistant to a particular Z. tritici isolate, then that isolate will never invade the leaf. However, it appears that such 'avirulent' isolates can persist on the leaf surface instead, and even reproduce there, making new spores for dispersal to more susceptible wheat plants. Most plant pathogenic fungi, by contrast, can't obtain enough nutrients on the leaf surface to survive for more than 24 hours. I therefore want to determine, firstly, how important this leaf surface growth phase is for Z. tritici, and whether it is related to how effective the fungus is at causing disease. I also want to find out whether some isolates are more likely than others to spend a prolonged period of time on the leaf surface, and whether such differences in behaviour can be attributed to differences in the genomes of the fungal isolates. Secondly, I aim to determine what nutrients the fungus is using when it is on the leaf surface. For example, the fungus might be relying on internal lipid stores, or taking advantage of nutrients that are exuded from the leaf, or of agricultural inputs like fertilisers. Alternatively, it might be able to secrete enzymes which digest structural components of the leaf such as waxes, to obtain nutrients from those. The fungus might also be able to take advantage of the activities of other microbes on the leaf surface which secrete such enzymes, or which cause nutrients to leak from the leaf by damaging the leaf surface. Thirdly, therefore, I intend to sample wheat leaves in the field and use metagenomics to study which microbes are present on the leaf surface. I will then compare these microbial communities, taking note of how severely affected the wheat in each field was by Z. tritici, to look for correlations between the presence of particular microbes and the promotion of fungal infection. Having obtained these data about leaf surface growth in Z. tritici, I intend to use them to build a detailed picture of what the fungus needs to survive throughout this first period of infection, before it enters the leaf; or to persist and reproduce on the leaf surface if the wheat is resistant and it cannot enter. This will allow me to identify any vulnerabilities the fungus has that we might be able to exploit in order to control the disease. For instance, if leaf surface growth is boosted by the presence of fertiliser, then it may be possible to increase the usefulness of fungicides by inter-relating the timings of fertiliser and fungicide application. Alternatively, if the fungus relies on a particular metabolic pathway to obtain nutrients, then that pathway could be targeted for new forms of chemical or other control. Or, if the fungus gains a large advantage sharing the leaf surface with a particular bacterium, then controlling that bacterium, perhaps via bio-control with a competing bacterium that is not able to promote fungal growth, might indirectly control the fungus.

Our vision is to maximise the food potential of UK pasture by using targeted chemical processing and novel biotechnology to convert grass into nutritious edible fractions for healthier and more affordable alternative foods, making UK agriculture more resilient and sustainable. Our proposal aims to use novel chemical processing methods to extract the central edible fractions from grass (protein, digestible carbohydrates, vitamins, lipids, fibre) before culturing the yeast Metschnikowia pulcherrima on the cellulosic fraction to produce mycoprotein and a lipid suitable as a palm oil substitute. These ingredients will then be combined in a range of alternative meat and dairy products, displacing environmentally damaging imported ingredients currently used. Further processing of the waste products from the process will produce nutrient rich fertilizers and help create a model for future circular farming economies. When optimised this process would only need 10 to 15kg of fresh grass (20% dry matter content) to produce 1kg of edible food ingredients, of which approximately 25% would be lipid and 35% protein. Whilst not entirely comparable on a nutritional basis this represents a ten-fold increase in productivity compared to cattle raised for meat, or twice the productivity of dairy cows. By converting grass into edible food components, a number of advantages are realised including: - UK produced substitutes for palm oil, soya protein, and other imported food ingredients. This has environmental benefits in the UK and abroad. It will provide UK produced healthy nutritional substitutes for ingredients grown on former rainforest sites, whilst significantly reducing food miles; - Produce UK food substitutes for over two billion pounds worth of annual food imports, with the opportunity to export significant quantities of surplus produce; - Improved UK resilience to climate change as grass is more resilient to flooding and other extreme weather conditions than most other crops; - As the process is feedstock agnostic, it should work equally well with wildflower rich pasture grass. This potentially enables the reintroduction of grasslands with greater biodiversity without having an impact on the grasses usability, an environmentally beneficial by-product of the process; - Providing a commercially viable non-livestock based market for forage production that would also allow arable land that is prone to flooding to profitably return to meadow grass production; - The profitable inclusion of grass in arable rotations to help combat blackgrass and other pesticide resistant weeds; - At present, in some areas it is uneconomic to build and maintain livestock fencing, resulting in grassland in these regions having little commercial agricultural value. These grasslands will now become commercially viable, and contribute to UK food production; - Limited risk in scaling up as there is no need to invest in new farm machinery, existing forage equipment and storage facilities will suffice and the bio-processing technology is mature and already used for many other industrial applications; - Opportunities for investment in a new UK food industry; - With the production of more digestible fractions, this project would produce more sustainable, UK sourced, feed for monogastric livestock; - Initial research suggests that sufficient unutilised grass is available for the P2P process, therefore, this system should have little or no impact on grass supplies for dairy and livestock farming.