Eliminating Fusarium Head Blight susceptibility in wheat

Wheat, grown on more land than any other crop, is the most important food grain source for mankind, it provides 20% of our calories, is the major source of protein for the poor, and is by far, the major European crop. Fusarium head blight (FHB) is a major threat to wheat production. FHB reduces yields and leads to the accumulation of mycotoxins in grain. Most UK wheat varieties are highly susceptible to FHB and achieving resistance remains a major challenge internationally. Traditionally, research has focussed on identifying FHB resistance and introgressing genes of major effect into commercial varieties. In this project we aim to exploit our discovery that wheat is complicit in its own downfall. This is because carries FHB susceptibility factors that actually assist the fungus. This finding means that a new approach can be taken - the targeted elimination of susceptibility.
We have identified three locations in the wheat genome that confer susceptibility to FHB. The aim of this project will be to physically map these regions with the long term intention of isolating the genes responsible. A pre-existing gamma-irradiated population of a FHB susceptible wheat cultivar will be used to generate a deletion map of the target regions. Previous studies have established the deletion frequency within these materials. A tiling path of overlapping chromosomal deletions covering the FHB susceptibility loci will be constructed and used to dissect each of them by putting together genomic and FHB resistance data. In this way the position of the FHB susceptibility factor will be refined. The gene content of the newly defined loci will be revealed by alignment of deletions to closely related cereal species for which genome sequence is available (gene content prediction by synteny) and increasingly by the more direct comparison with the rapidly emerging wheat genome sequence. These approaches will allow the identification of candidate FHB susceptibility genes, which will then be studied in detail for expression profiles. If time permits wheat TILLING populations will be screened to identify and disease screen mutants in the susceptibility factor candidates.
In addition to providing an outstanding opportunity to work at the forefront of crop science, this project includes collaboration with a dynamic wheat research team with the company RAGT to provide the student with an insight into commercial plant breeding.