Methylation modification of Toxin gene of Bacillus thuringiensis in wheat

Wheat varieties Jinghua No. 5 and 86A1 were transformed with Bt toxin gene (Bt gene for short) cloned in E. coli from Bacillus thuringiensis via pollen tube pathway. By using dot hybridization, Southern blotting and PCR assay, Bt gene in T 0 and T 1 transgenic plants was identified, and its integration into wheat chromosomes was proved. In addition, changes in methylation of Bt gene in progenies of transgenic plants were revealed by analyzing the profiles of both wheat genemic DNA digested with cytosine and adenine methylation-sensitive restriction enzyme group (MREG) and digest-PCR products. The results showed that the methylation pattern of Bt gene when integrated into wheat genome was different from that in E. coli as the former was C +A - and C +A + and the latter C -A +.