热诱导FLP重组酶删除转基因烟草外源基因

Heat inducible FLP recombinase mediated gene excision from transgenic tobacco

利用热激启动子Hsp18．2、nP重组酶基因及其专一识别位点构建了重组酶删除系统的植物表达载体转化烟草。热激处理后转基因植株中FLP重组酶表达并识别两个同向lox P-frt重组酶识别位点，使两位点间的DNA插入片段（包含kn1、gus、nptⅡ基因）从转基因烟草基因组中删除，由kn1基因引起的转基因烟草特殊表型及gus基因产生的蓝色表型消失。

A novel plant expression vector with gene deletion function was constructed by using the heat shock promoter and site-specific recombination system, and transformed into tobacco. FLP recombinase, under the control of heat shock promoter Hsp18.2, catalyzed the foreign DNA （including knl, gus and npt Ⅱ gene） flanked by two identical orientation loxP-frt sites to be deleted from genomics of transgenic tobacco. The results of GUS assay and PCR analyzing showed that the FLP recombination system could precisely mediate the excision of foreign genes from transgenic plants. The special phenotype caused by knl gene in transgenic plants was recovered after heat shocking treatment.