Novel Approach using Digestive and Neurotoxins to Confer Resistance against Helicoverpa armigera and Myzus persicae in Tobacco

A new and improved strategy for the delaying of insect resistance by stacking two different genes with different mode of action was practiced. In the present study stacked gene construct having a spider toxin gene i.e., omega-ACTX-Hvla toxin (Hvt, a neurotoxin) and digestive toxin Vip3A derived from Bacillus thuringiensis was developed and transformed into tobacco (Nicotiana tabacum L. cv. Spade). The expressed transgenic tobacco expressing stacked genes showed the paralysis of Helicoverpa armigera Hubner larvae after 24 h and 100% mortality within 48 h. Loss of weight after 48 h was also observed for H. armigera larvae feeding on transgenic plants as compare to control plants where gain in weight was observed. The transgenic tobacco plants also showed reduced colony growth of aphid (Myzus persicae Sulzer) after 10 and 14 days as compared to control plants. Aphid showed less gain in weight on transgenic plants as compare to control plants. Commercial use of this construct in agronomical important crops will reduce the use of chemical pesticides as it is effective against both sucking and chewing insects. (C) 2019 Friends Science Publishers