盾叶薯蓣3-羟基,3-甲基戊二单酰辅酶A还原酶和环阿屯醇合成酶基因克隆及序列分析

Cloning and Sequencing of HMGR and CS Gene of Dioscorea Zingiberensis

根据已报道的植物3-羟基，3-甲基戊二单酰辅酶A还原酶（HMGR）和环阿屯醇合成酶（CS）基因保守序列分别合成简并引物，先后从盾叶薯蓣（Dioscorea zingiberensis）幼苗中克隆了一段663bp（HMGR—DZh）和一段1245bp（CS—DZc）的cDNA片段，经NCBI和CLUSTALW在线序列同源分析，结果表明，由HMGR—DZh cDNA推导的蛋白质与已报道植物HMGR氨基酸序列相似性达到63％～70％．由CS—DZc cDNA推导的蛋白质氨基酸序列中具有环氧角鲨烯环化酶（OSCs）特异保守结构域：DCTAE结构域和C末端的2个QW高度保守区，并与已报道植物环阿屯合成酶氨基酸序列相似性达到80％以上．本实验还分别以HMGR—DZh和CS—DZc cDNA为探针进行了Southern和Northern杂交分析．Northern杂交分析表明，盾叶薯蓣HMGR—DZh基因的mRNA约为1．8～2kb．CS—DZc基因的mRNA约为2～2．5kb．

A 663 bp cDNA fragment （ HMGR-DZh ） and a 1 245 bp cDNA （ CS-DZc ） fragment were cloned from the seeding of Dioscorea zingiberensis by RT-PCR method. Sequencing analyses by NCBI blast and CLUSTALW alignment showed that, the HMGR-DZh protein had 63 % ～70 % identity with HMGR protein of other plants reported. The comparability of CS-DZc protein to CS protein of other plants reported was up to 80 %. The DCTAE and two QW high conservative domain, which was characteristic in CS protein, were found in the C tag of CS-DZc. Northern blotting has showed that the full-length mRNA of HMGR-DZh is about 1.8 ～2.0 kb and CS-DZc is about 2.0～2.5 kb.