Abstract:

RNAi, the mechanism of which is down regulation of specific gene through dsRNA, has a potential for preventing insect by post-transcriptional gene silencing. The interfering sequence of Aphis gossypii gene Cathepsin B was cloned and the RNAi vector about the interfering sequence was constructed and transferred into tobacco (Nicotiana benthamiana). The RNAi vector was transformed into tobacco via Agrobacterium-mediation using leaf disc method and the regenerated tobacco plants were obtained. Among the 15 strains of transgenic tobacco obtained after tissue culture, 14 lines are positive detected by PCR. And the analysis of RT-PCR and Northern blot of transgenic tobaccos displayed the existence of expression of dsRNA. These results demonstrated that transgenic plants containing RNAi could express dsRNA. For this reason, there was possible that aphid could be resisted when they fed on the transgenic plants.