Creation of Borer Pests Resistance Genetically Engineering Peach (Prunus Persica L.) Plants by Cloning cry1Ab Gene

Abstract The plasmid pBI121 cry1Ab was used to transform peach explants to produce insect resistant plants. The plasmid was constructed from cloning the synthetic cryIAb gene with intron of castor bean catalase-1 gene into the pBI121 binary vector under the control of CaMV35S promoter. Leaf discs of peach (Prunus Persica L.) were co-cultivated for two days with A. tumefaciens strain LBA 4404. Explants were plated on WPM medium supplemented with 125 mg/l kanamycin, 3% sucrose, 2.5 mg L-1 2,4-D (2,4-Dichlorophenoxyacetic acid) and 0.5 mg/l BA (6-benzyladenine) in darkness for callus formation. The calli were then selected on WPM medium supplemented with 125 mg L-1 kanamycin, 3% sucrose, 3.00 mg L-1 TDZ (Thidiazuron), 1.0 mg L-1 Kn (kinetin) and 0.5 mg L-1 IAA (Indoleacetic acid) in the light for at least five subcultures (with a regeneration efficiency of 91.8%). The integration of cryIAb gene into the peach genome was confirmed by PCR (polymerase chain reaction) and northern blot analysis. The transformation efficiency (28%) was obtained when leaves were incubated for 15 min. with A. tumefaciens. The cryIAb gene expression was confirmed using RT-PCR, northern blot hybridization, immune-strip test and insect bioassays, respectively. For insect bioassay, it was evident from data the toxin CryIAb protein expressed in transformed peach plants showed 100% mortality at 1000 ppm against Synanthedon exitiosa larvae’s after 96 hr. These results obtained improved significantly of CryIAb toxin protein against lepidopteron larvae of peach.