Over-expression of Gastrodia anti-fungal protein enhances Verticillium wilt resistance in coloured cotton

Currently there are no adequate control measures for the cotton fungal diseases Verticillium wilt and Fusarium wilt, which are important factors limiting yield under certain conditions. In this study the gene encoding a Gastrodia anti-fungal protein was introduced into three cultivars of coloured cotton using the method of pollen-tube pathway transformation, with the purpose of obtaining transgenic plants with improved resistance to wilt. Of the 121 herbicide-resistant cotton plants two, LB-5-8 and ZB-1-49, were scored as transgenic based on Southern blot, RT-PCR analysis and in vitro anti-fungal activity assay. Field analysis demonstrated that the transgenic lines LB-5-8 and ZB-1-49 possess an increased resistance to wilt. After 2 years of breeding, the progeny of LB-5-8 and ZB-1-49 lines still showed a stable and strong resistance to Verticillium wilt. Lines with high levels of resistance to Verticillium wilt obtained from the present study may be widely planted and help to reduce the future impact of cotton wilt on cotton production resulting in increased yields.