Fov is the causal organism of Fusarium wilt disease in cotton. This disease is of serious concern to the cotton industry in terms of potential yield loss. Existing CRDC projects in progress to identify genes associated with cotton’s response to Fov infection (CSP114C) including those genes associated with the expression of moderate resistance. Once potential genes have been identified as being associated with resistance responses, it is necessary to confirm that these genes are playing an active role in the expression of this resistance. One approach that may be used to verify the role of any particular gene in resistance is to generate transgenic plants in which the expression of this gene has been altered and to look for a change in disease resistance. This is not feasible in cotton but would be feasible in the model plant Arabidopsis thaliana, where suitable genomics tools (e.g. rapid and simple transformation, complete genome sequence, diploid plant) are available. One of the aims of this project was therefore to establish a model Arabidopsis/Fusarium oxysporum system to complement studies with cotton and Fov. We wished to know if the importance of genes detected in the cotton microarray work (CSP114C) could be assessed rapidly in Arabidopsis and if it would have been feasible to perform gene discovery work in the system for application to the cotton system. In order to achieve this we needed to set up and develop expertise in the Arabidopsis/Fusarium infection system.

The second part of the pilot project dealt with developing the tools required to undertake a study of the molecular basis of pathogenicity of Fov. This may have lead in the long term to the development of novel disease resistance strategies. In order to undertake molecular analysis of the pathogen, a transformation system for Fov is required. We wished to apply an Agrobacterium-based transformation method developed for Fusarium oxysporum pathogens of Arabidopsis to the cotton pathogen Fov. Initially we planned to introduce reporter genes into the fungus to generate transgenic strains with immediate practical use in studying Fov infection dynamics in experimental systems and in the glasshouse.

It was hoped that development of these technologies would form the basis for a further project aimed at verification of the role of genes already discovered, the discovery of novel plant genes and the elucidation of pathogenesis mechanisms in Fov.