大肠杆菌%otsA%基因的克隆和表达

用ＰＣＲ方法扩增了１．５ｋｂ的ｏｔｓＡ基因片段，将该片段连接到多拷贝克隆载体后转化ｏｔｓＢＡ缺失和ｏｔｓＡ缺陷的大肠杆菌菌株，使转化株重新获得ｏｔｓＡ基因功能。生长曲线表明转化株在高渗培养基中生长良好，薄层层析法（ＴＬＣ）检测海藻糖实验说明转化株细胞诱导后合成海藻糖，ｏｔｓＡ基因的克隆和表达为赋予转基因植物抗高渗、耐干旱能力提供了实验依据和材料。

CLONING AND EXPRESSION OF otsA GENE IN E. COLI

1.5 kb of otsA gene encoding trehalose synthase has been cloned by PCR amplification. The DNA fragment was ligated to multi-copy vector and transformed to otsBA deleted and otsA deficient strains of E. coli separately. The transformants exhibited growth as well as the otsBA+ wild type on medium containing 0.5 mol/L NaCl. Trehalose was synthesized and accumulated in the transformed cells under osmotic pressure, which was determined by thin layer chromatograph. The results confirmed that otsA gene was functionally expressed in the recipient strains. These studies suggested that engineering otsA gene and trehalose accumulation into crop plants may improve drought and salinity tolerance.