Production of marker-free transgenic Jatropha curcas expressing hybrid Bacillus thuringiensis ?-endotoxin Cry1Ab/1Ac for resistance to larvae of tortrix moth (Archips micaceanus)

Abstract

Background: The potential biofuel plant Jatropha curcas L. is affected by larvae of Archips micaceanus (Walker), a moth of the family Tortricidae. The hybrid Bacillus thuringiensis (Bt) ?-endotoxin protein Cry1Ab/1Ac confers resistance to lepidopteran insects in transgenic rice. Results: Here, we report the production of a marker-free transgenic line of J. curcas (L10) expressing Cry1Ab/1Ac using Agrobacterium-mediated transformation and a chemically regulated, Cre/loxP-mediated DNA recombination system. L10 carries a single copy of marker-free T-DNA that contains the Cry1Ab/1Ac gene under the control of a maize phosphoenolpyruvate carboxylase gene promoter (P Pepc:Cry1Ab/ 1Ac:T Nos). The P Pepc:Cry1Ab/1Ac:T Nos gene was highly expressed in leaves of L10 plants. Insecticidal bioassays using leaf explants of L10 resulted in 80-100% mortality of larvae of A. micaceanus at 4 days after infestation. Conclusion: The results demonstrate that the hybrid Bt ?-endotoxin protein Cry1Ab/1Ac expressed in Jatropha curcas displays strong insecticidal activity to A. micaceanus. The marker-free transgenic J. curcas line L10 can be used for breeding of insect resistance to A. micaceanus. © 2014 Gu et al.; licensee BioMed Central Ltd.