Transformation And Light Inducible Expression of cry1Ab Gene in Oilseed Rape (Brassica napus L.)

Rapeseed (Brassica napus L.) is the third most important oil crop in global productions. One of the major limiting factors for oilseed rape production is lepidopteran pests of the Brassicaceae family. Transgenic plants expressing Bacillus thuringiensis (Bt) genes are powerful tools in the integrated pest management of crop plants. In the present study, we used a synthetic Bt insecticidal crystal protein gene (cry1Ab) under the control of the phosphoenolpyruvate carboxylase (PEPC) promoter for genetic transformation of B. napus L. (var. SLM046) using Agrobacterium tumefaciens-mediated transformation. PEPC-cry1Ab-nos cassette cloned in a binary vector pCAMBIA3300 containing bar gene as a selection marker. The new vector (pCAMBIAPEPCry) introduced to AGL01 strain of A. tumefaciens, which used in transformation of hypocotyl explants of B. napus. Putative transgenic rapeseed plants were regenerated in selection media containing phosphinothricin (PPT) as selection agent. Polymerase Chain Reaction (PCR) confirmed the integration of cry1Ab and bar genes at putative transgenic plant genome. Furthermore, transcription (mRNA production) and protein expression of cry1Ab gene was confirmed using RT-PCR and immune-strip methods, respectively. Transgenic B. napus plants expressed Cry1Ab protein in the shoots and not in the roots. We concluded that C4 maize PEPC promoter can induce the expression of Cry1Ab recombinant protein only in light treated (green) tissues in rapeseed plants. It recomended as a light inducible promoter for targeted expression of transgene in the rapeseed plants.