Characterization of resistance mechanisms from Heliothis virescens exposed to multiple Bt toxins

New varieties of transgenic crops expressing multiple Cry toxins from Bacillus thuringiensis (Bt) are being commercialized for increased range of activity and to delay the evolution of resistance to Bt crops. However, some laboratory-selected strains of Heliothis virescens, a major agricultural pest, display cross-resistance to diverse Cry toxins. In an effort to understand the cross-resistance mechanisms that may develop in H. virescens from the field, we performed comparative proteomic and genomic analyses of the response to Cry intoxication in laboratory strains of H. virescens. The mechanisms of resistance to diverse Cry toxins suggested by the combined proteomic and genomic analysis in different strains of H. virescens will be presented.