Healthier crops with less fertilizer

There is an increasing need to develop crops that have improved disease resistance to reduce dependence on pesticides and benefit the environment. In addition, as natural resources become scarcer, there is a need to develop crops with reduced dependence on inorganic fertilizers such as Nitrogen and Phosphorus. Many plant varieties, including barley and other cereals, form symbiotic mycorrhizal associations with soil fungi that enable nutrients including P and N to be assimilated. Breeding efforts are, however, targeted to deploy resistance genes that protect against harmful diseases. The trade-off between selection for resistance and mycorrhization is largely unknown, and is the subject of this PhD project. The work involves investigation of genetic variation in different barley genotypes to determine whether modern breeding has selected against mycorrhization. Also, the effect of specific resistance genes on the symbiotic association will be investigated. The widely-used mlo gene, which confers resistance against powdery mildew, could have a negative impact on mycorrhization. This will be tested with a series of allelic variants for mlo and modifiers of the gene. Immune responses induced by chitin, a constituent of the fungal cell wall, will be tested for their involvement in establishment of mycorrhiza using RNAi silenced lines with reduced chitin perception. The research will provide the basis for breeding improved varieties for sustainable yield with reduced inputs. The project provides high-quality training in plant pathology and mycorrhizal biology, molecular biology, plant genetics, bioinformatics and statistics. The student will benefit from working with three labs, each specialising in plant immunity, mycorrhization and cereal genetics.