In-planta expression of insecticidal proteins provides protection against lepidopteran insects.

The development of advanced biotechnological control strategies opens a new era of environment friendly pest management. The current study is part of such an effort, in which we developed a control strategy based on gene pyramiding that confers broad-spectrum resistance against lepidopteran (Helicoverpa armigera and Spodoptera litura) and hemipteran (Myzus persicae, Phenacoccus solenopsis, and Bemisia tabaci) insect pests. Previously, we reported a double gene construct expressing Hvt and lectin in tobacco (Nicotiana tabacum) plants under phloem specific promoters which confers resistance against hemipteran insects. Here we extended our studies by evaluating the advanced generation of these tobacco plants expressing hvt-lectin against lepidopteran insects. Tobacco plants expressing both toxins were tested against H. armigera and S. litura. Insect bioassay results showed 100% mortality of H. armigera within 48-72 hours and 100% mortality of S. litura within 72-96 hours. Our results suggest that the use of both toxins as a gene pyramiding strategy to control both lepidopteran and hemipterans insects on commercial basis to reduce the use of chemical pesticides.