CMO与BADH双基因表达载体构建及在烟草中的表达

本研究的目的是将甜菜碱合成关键酶CMO与BADH基因构建到同一表达载体中，利用转基因方法将该表达载体导入植物体内，完善植物体内的甜菜碱合成途径，提高植物的抗旱性和耐盐性。以pC1303质粒为基础，构建了均由35S启动子驱动的CMO基因和BADH基因的植物双基因表达载体pC35SC35SB1303。利用冻融法将其导入农杆菌LBA4404中，通过农杆菌介导法分别将CMO基因、BADH基因以及该双基因表达载体导入烟草中，PCR检测和Northern杂交分析表明，外源基因已整合到受体植物基因组中并正常表达。对转基因植株及对照植株甜菜碱含量的检测结果表明，转双基因植株的甜菜碱含量明显高于转BADH基因植株、转CMO基因植株及对照植株。

Construction of CMO-BADH bivalent-expression vector and its expression in tobacco

The objective of this research is to perfect the approach for synthesizing bataine in plants in order to improve the resistance of drought and salt by transferred CMO and BADH genes into the target plants. A bivalent-expression vector, pC35SC35SB1303　were reconstructed based on PC1303 plasmid with CMO and BADH driven by 35S promoter and introduced into Agrobacterium tumefaciens strain LBA4404 by freezethaw method. Transgenic tobacco plants recovered from leaf discs applying Agrobacteriummediated gene were detected by PCR analysis and Northern blotting. The results showed that the foreign gene was consistent with the recipient plants' genome and expresses normally. The analysis of the content of bataine in transgenic plants and blank plants showed that it was higher in the bivalent-expression vector transgenic plants than those transferred with single gene BADH or CMO and blank plants.