Cre site-specific recombinase-mediated DNA excision system was driven by the heat shock promoter Gmhsp17.5C. In this system, the DNA fragment with CaMV35S-GUS franked by two identical orientation loxp sites could be excised from the transgenic tobacco (Nicotiana tabacum L. cv. W38) by Cre expression under control of heat shock promoter. This transgenic system has been determined by quantitative PCR and showed Cre/lox mediated recombination efficiency. Results showed that 41% of DNA fragment with CaMV35S-GUS in the transgenic tobacco could be excised after a two-hour heat shock treatment. Based on several advantages of heat shock-inducible site-specific recombination system such as easy manipulation, sensitivity to heat shock and no background expression, it can be potentially used for inducible DNA manipulation in transgenic plant.
