表达肌醇甲基转移酶基因载体的构建及转基因烟草的耐盐性研究

构建了肌醇甲基转移酶（Imt1）基因的植物表达载体pDH5, 通过农杆菌（Agrobacterium）介导，获得了转基因烟草(Nicotiana tabacum L. cv. SR1)植株，在附加1.2%～1.5% NaCl的生根培养基MSr(MSO 3 g/L蔗糖 7 g/L 葡萄糖)上可生根。 生化分析表明，不具有芒柄醇（D-ononitol）合成途径的烟草鲜叶片积累了100～654 nmol/g的芒柄醇, 新产生了一个代谢分支。Western杂交分析证明Imt1基因在烟草中的表达，从而为植物耐盐的基因工程育种提供了一条新途径。

Construction of Vector with IMT1 and Its Gene Expression in Transgenic Tobacco Leaf Cells Associated with Salt Tolerance

The plant expression vector with Imtl (inositol O-methyltransferase) gene, pDH5, was constructed. The Imtl gene was introduced to tobacco (Nicotiana tabacum cv. SR1) via Agrobacterium-mediated transformation. Thirty kanamycin-resistant shoots in MSS (MSO + 1 mg/L 6-BA + 30 g/L sucrose) selective medium was transferred to MSr (MSO + 3 g/L sucrose + 7 g/L glucose) medium supplemented with 1.2%~1.5% NaC1 for rooting. Eight plantlets rooted among the thirty shoots. PCR and Southern blot assay indicated that the Irntl gene was integrated into tobacco genome in six plantlets. HPLC analysis showed that the product of Imtl gene, D-ononitol accumulated in tobacco fresh leaf cells in a scope of 100 - 654 nmol/g FW. Western blot demonstrated the expression of Imtl gene in tobacco cells.