Development of Insect-Resistant Transgenic Cotton with Chimeric TVip3A Accumulating in Chloroplasts

An optimized vip3A gene, designated as vip3undefined was chemically synthesized and a thi1 gene chloroplast transit peptide coding sequence was attached to its 5′ end to produce the tvip3undefined . vip3undefined and tvip3undefined genes were transformed into Gossypium hirsutum cv. Zhongmiansuo35 mediated by Agrobacterium tumefaciens . Four independent transgenic T1 lines with single-copy insertions and unchanged phenotypes (CTV1 and CTV2 for tvip3undefined , and CV1 and CV2 for vip3undefined ) were selected by Polymerase chain reaction (PCR), Reverse transcription (RT)-PCR, Southern blotting, enzyme-linked immunosorbent assay (ELISA), and insect bioassay. As expected, the Vip3undefined protein of CTV1 and CTV2 were transported to the chloroplasts, where they accumulated. Our results suggest that the two tvip3undefined transgenic lines (CTV1 and CTV2) can be used to develop insect-resistant cultivars and could be used as a resource for raising multi-toxins-expressing transgenic cotton.