The overall aim of this project was to develop systems for targeting transgene expression in plants to enhance their defence responses.

We were investigating two methods for the regulation of the expression of transgenes in transgenic cotton. One method involved limiting gene function by insertion of the transposable element Ac. Transposition of the Ac element (where the Ac element “jumps out” of the gene) can cause localised re-activation of the target gene. This could be used to give small areas of localised gene expression in instances where constitutive expression of the gene in all cells would have a detrimental effect. This could be useful in the case of avirulence genes, for example. The use of transposable elements has other potential uses for gene tagging and we wished to demonstrate its feasibility in cotton. The second method involved an investigation of the behaviour of some potentially pathogen-inducible promoters as drivers of transgene expression. In this study our focus was on the PR10 gene family. Members of this gene family are highly induced by Fusarium infection of cotton – in fact they constitute a significant component of cotton’s responses to Fusarium.