Expression of stilbene synthase gene in transgenic tomato using salicylic acid-inducible Cre/loxP recombination system with self-excision of selectable marker.

A plant transformation vector, pCLKSCLA25 (EU327498), was developed to contain eight cloning sites and the inducible self-excision system which provided an effective approach to eliminate the selectable marker gene(s) from transgenic plants. Upon induction by salicylic acid, the cre gene produced a recombinase that eliminated sequences encoding the selectable marker neomycin phosphotransferase and cre itself. The excision efficiency was 41% in transgenic tomato regenarants. The stilbene synthase gene (vst1) from Vitis vinifera L. was cloned into pCLKSCLA25. The expression of vst1 gene contributed to the accumulation of trans-reveratrol from 3.4 to 8.7 mug/g fresh wt in different marker-free transgenic tomato lines.