猪肝脏BHMT基因植物表达载体构建及玉米遗传转化

Construction of plant expression vector with Sus scrofa liver BHMT gene and its transformation in maize

甜菜碱高半胱氨酸甲基转移酶(BHMT)是一种甲基代谢酶,在动物和微生物体内存在,能催化甜菜碱向高半胱氨酸转移甲基,促进甲硫氨酸形成。本试验通过RT-PCR扩增猪肝脏BHMT基因ORF的cDNA序列,成功构建了p3301-BHMT植物表达载体,并利用农杆菌介导法转化玉米萌动胚,经PPT筛选和PCR检测,初步确定获得4株抗性植株。试验结果将为研究BHMT基因在植物中的作用,提高玉米甲硫氨酸含量和抗逆性提供试验材料。

Betaine-homocysteine methyl transferase（BHMT）,a methyl-metabolizing enzyme found in animals and micro-organisms,can catalyze methyl of betaine shifting to homocysteine and forming methionine.However,there has been no report of its expression in plant until now.This study amplified the ORF sequence of BHMT from Sus scrofa liver by RT-PCR,and successfully constructed the plant eukaryotic expression vector p3301-BHMT.The p3301-BHMT vector was transformed into germinating embryo of maize by Agrobacterium-mediated method.4 transgenic plantlet strains were obtained through screening by repeatedly spraying PPT and genomic DNA PCR with specific primers.The results provide useful materials for improving methionine content and stress resistance in maize with BHMT.