胆碱脱氢酶基因的转化及转基因番茄耐盐性的鉴定

Transformation of Choline Dehydrogenase Gene and Identification of Salt-tolerance in Transgenic Tomato

采用PCR方法从E .coliTG1菌株中扩增得到胆碱脱氢酶 (cholinedehydrogenase ,CDH)基因 (betA) ,其氨基酸编码序列与文献中的资料一致 ,且能在原核表达载体pBV2 2 1中正确表达 ,并表现出活性。构建该基因的植物表达框架pRbA ,经农杆菌介导叶圆盘法转化番茄 ,对转基因番茄的PCR、Southern、RT PCR分析证实betA已整合到番茄基因组中 ,转基因番茄的耐盐性高于对照番茄。

The betA gene which encodes choline dehydrogenase that converts choline into glycinebetaine has been cloned from Escherichia coli TG1. Agrobacterium-mediated transformation has been used to introduce the betA gene under the control of the 35S promoter of cauliflower mosaic virus as well as the nptⅡ marker gene into tomato (Lycopersicon esculentum). Salt tolerance assays were performed on two independent transgenic plants. Under salt stress, the osmotic adjustment ability of the transgenic tomato was higher than that of the control plant(Fig.6). At 200 mmol/L NaCl, there is no visible symptoms of salt damage in transgenic tomato whereas the lower leaves of the control plant turned yellow and exhibited necrosis. The results suggest a positive effect of the betA gene on the level of salt tolerance in transgenic plants.