Efficacy of transgenic tobacco carrying synthetic plant-preferred codon-optimized novel VIP3AA44 Gene towards Helicoverpa armigera and Spodoptera litura

Abstract

Vip3A proteins are synthesized during vegetative growth of Bacillus thuringiensis and are toxic against a wide range of lepidopteran insects. Since the mode of action of vip3A toxins is different from Cry proteins, vip3A proteins are good candidates for gene pyramiding in transgenic crops to combat development of resistance against the currently deployed genes. A synthetic plant-preferred codon-optimized novel vip3Aa44 gene (NCBI accession number HQ650163) was cloned into pBINAR plant transformation vector and tobacco explants were transformed with leaf disc co-cultivation method to evaluate toxicity of this gene against Helicoverpa armigera and Spodoptera litura. The putative transgenics were confirmed by PCR and RT-PCR analysis. The bioassays were performed on detached leaves from putative transgenics using lab-grown population of H. armigera and S. litura. Mortality after 72 hr ranged from 30–56% for H. armigera and 40–60% for S. litura, indicating potential of vip3Aa44 gene against these lepidopteran pests in transgenic development.