马铃薯P_(GBSS)-GUS融合基因在块茎中专一性表达的初步研究

A preliminary study on tuber-specific expression of P_(GBSS)-GUS fusion gene in transgenic potato

从GBSS（Granule－boundstarchsynthase）基因克隆上，酶切得到5’上游区1．2kb的序列，与GUS报告基因融合，构建了PGBSS1．2表达载体．通过农杆菌介导的方式，将pGBSS1．2转入马铃薯品种Desiree．卡那霉素筛选获得抗性再生植株和微薯．利用PCR特异性扩增和SouthernBlotting的方法证明了融合基因在马铃薯基因组中的整合．X－Gluc活体染色表明，微薯切片具有高GUS酶活性．而茎段中GUS活性相对较低．初步证明GBSS启动子是高效和块茎专一性的启动子，从而为马铃薯生物反应器的研究打下良好的基础．

An expression vector pGBSS1. 2 was constructed by fusing 1. 2 kb 5' upstream region of GBSS(Granule-bound starch synthase ) gene with GUS (beta-glucuronidase ) reporter gene. After pGBSS1. 2 was introduced into Potato (Solantlln tubal-,)sunl c. v. Desiree ) plant by an Agrobacterium binary vector system. kanamycin-resistant plantlets and micro-tubers were obtained. X-Glue histochemical analysis showed high GUS activites in tubers,whereas these activities were very low in stems. By PCR and Southern blotting,it had been shown that this chimaeric pGBss-GUS gene was being integrated into genomic DNA of the regenerated transformants. Also,the 1. 2 kb promoter region of GBSS is highly-active and tuber-specific,and might be of great potential in potato bioreactor research.