菠菜甜菜碱醛脱氢酶基因在烟草中的表达

质粒pLS9含有1．5kb的编码菠菜甜菜碱醛脱氢酶(BADH)基因。经限制酶切后克隆到植物表达载体的35S启动子和PolyA终止子之间。经农杆菌介导转化烟草，获得90多株抗卡那霉素再生植株。经PCR检测证明60％以上再生植株含有BADH基因。转基因植株经Western blot，BADH酶活性测定，BADH酶活性特异性染色法检查和耐盐性分析，证明菠菜BADH基因在烟草正常表达。在叶绿体和胞液中均有BADH酶存在。转基因植株能耐较高浓度盐。

Expression of the Spinach Betaine Aldehyde Dehydrogenase (BADH) Gene in Transgenic Tobacco Plants

Plasmid pLS9 contains a 1.5 kb of spinach BADH cDNA including its complete open reading frame.The 1.5 kb of BADH cDNA was cutted from pLS9 using restriction enzyme and was inserted into the expression cassette of pYH between the 35S promoter and polyA terminator.The 35S BADH gene polyA fragment was cloned into binary vector pBin19 in the polylinker site.Resulting plasmid pBinBADH S was introduced into Agrobacterium tumefaciens LBA4404.The BADH gene was transformed to tobacco plants mediated by agrobacteria.Ninety kanamycin resistant transformants were selected.PCR detection showed that more than 60% of transformed tobacco plants contain the foreign BADH gene.Western blot analysis ,BADH activity assay and BADH specific activity stain showed that BADH gene was normally expression in the transgenic tobacco plants.The enzyme also occured in chloroplasts and the cytosol in the transgenic plants.Plants having strong expression of BADH gene had an ability to tolerate high salinity.