【摘要】 甘氨酸甜菜碱是一种非毒性的渗透调节物质 ,在植物体内是以胆碱为底物 ,经两步氧化而合成的 .菠菜中 ,催化第一步反应的酶为胆碱单氧化酶 (CholineMonooxygenase ,CMO) .为了研究胆碱单氧化酶基因的功能以及转基因植物的抗逆能力 ,在 30 0mmol L高盐浓度 (n(NaCl)∶n(CaCl2 ) =5 7∶1)的条件下 ,作者分离纯化了菠菜mRNA ,经RT PCR得到全长 (1.3kb)胆碱单氧化酶 (CMO)cDNA ,与已经报道的基因序列相比较 ,同源性为 99% .根据其核苷酸序列推导得到了氨基酸序列 .将PCR纯化产物与pET 30a+ 连接 ,构建了重组表达载体pETCMO ,并转化到大肠杆菌BL2 1(DE3) ,经IPTG诱导获得高效表达 .更多还原

【Abstract】 Plants synthesize the osmoprotectant betaine via the route of choline oxidiations. In spinach, the first step is catalyzed by Choline Monooxygenase (CMO). To study the functions of Choline Monooxygenase (CMO) and improve tolerance to salinity and low temperature in transgenic plant producing glycine betaine, a full length CMO cDNA (1.32 kb) was cloned from salinized spinach leaves using RT PCR amplification and expression vector pETCMO was constructed. The plasmid (pETCMO) was transformed into E.coli BL21(DE3) and the CMO was over\|expressed in E.coli BL21(DE3).更多还原