Molecular cloning of Ve promoters from Gossypium barbadense and G. hirsutum and functional analysis in Verticillium wilt resistance

Abstract

Verticillium wilt caused by Verticillium dahliae is the most serious disease in cotton. Ve gene isolated from Gossypium barbadense is one of the resistant genes related to Verticillium wilt. In this study, we analyzed Ve expression pattern in different resistant cotton cultivars under V. dahliae stress, and isolated the upstream promoters of Ve from G. barbadense and G. hirsutum. We found that the expression of Ve gene in upland cottons increased significantly at 6 hpi and decreased at 12 hpi, however, continued to increase in Sea Island cotton under V. dahliae stress. Through detecting the GUS activity in the transgenic pVe::GUS Arabidopsis, we discovered that the upstream from − 979 to − 1 bp was the important region of Ve gene promoter. The activity of Ve gene promoters was higher in the roots than that in other tissues in Arabidopsis, and the promoters could be induced by V. dahliae. Moreover, the activity of promoter in G. barbadense was significantly higher than that in G. hirsutum, and the promoter of Ve in G. barbadense contained regulatory elements S1FBOXSORPS1L21 and S1FSORPL21 compared to that in G. hirsutum. We inferred that the regulatory elements S1FBOXSORPS1L21 and S1FSORPL21 were related to the Ve gene expression. This provides new insights into dissecting the defense mechanisms of Ve against V. dahliae in cotton.