Transformation of potato using the cryIAb gene to produce potato tuber moth resistant transgenic plants.

Potato tuber moth (Phtorimaea operculella) is one of the most important pests in tropical and subtropical regions (e.g Iran). All attempts to improve potato plants for resistance to Potato tuber moth using conventional breeding methods have been failed. One of the best and common methods for biological control of the pests is the cry1Ab gene. This gene encoding a crystal protein that causes perturbance of the digestive apparatus of Lepidopteran insects and insect death follows. Cry1Ab protein has high mortality effects on Potato tuber moth. In the present work, we produced transgenic potato plants (Solanum tuberosum var. Marfona) using the cry1Ab gene under the PEPC (Phosphoenopyruvate carboxilase) promoter which obtained from Zea mays and induces cry1Ab gene expression in green tissues of plant and dose not express in potato tubers. PEPC-cry1Ab construct transferred in Agrobacterium tumefacience AGLO1 strain. The inter nod segment of potato plant were infected by the Agrobacterium. After 3 days co-cultivation, the explants were transferred to MS medium containing 100 mg/l kanamycine and 250 mg/l cefotaxime. The regenerated plants were transferred into rooting medium and finally the rooted plants were transferred in pots. More than 95% of regenerated plants showed cry1Ab gene in PCR analysis. Southern blot analysis for three selected lines showed that they have one copy number of cry1Ab gene. Western blot analysis demonstrated that Cry1Ab protein expressed in leaf tissue of transgenic potato plants. In vitro and greenhouse bioassay for leaves of transgenic plants showed 100% resistance against potato tuber moth larva. The non- lighted (white) transgenic tuber showed the same injury as non- transgenic tubers which demonstrates that Cry1Ab protein dose not expressed in white potato tuber. On the other hand, bioassay with green tubers (lighted) proved that cry1Ab gene expressed in such tubers. Therefore these transgenic potatoes could serve food safety issue. More greenhouse and filed studies for these transgenic plants are needed. We are going test them in another experiment. This study was the first report of transgenic potato using PEPC-cry1Ab in the world.