毛花猕猴桃果实L-半乳糖内酯脱氢酶基因cDNA 片段的克隆与序列分析

摘要

In order to investigate the molecular mechanism of Vc accumulation, 661 bp cDNA encoding L-galactono-1,4-lacton dehydrognease (GalLDH) fragment was cloned from fruit of Actinidia eriantha by the method of RT-PCR,and then translated into amino acid sequences.In GenBank, compared with Actinidia delicisa, the ammo acid sequence of GalLDH gene sequence showed 99％ identity with those of Actinidia delicisa and they were both classified in the same family.The amino acid sequence of GalLDH gene sequence showed 91％ identity with Vitis vinifera and more than 80％ identity with Fragaria xananassa , Rosa roxburghii , Ipomoea batatas , citrur unshiu , Arabidopsis thaliana and Cucumis melo.These results suggested that the cDNA fragment cloned in this stady was from GalLDH gene of Actinidia eriantha.%毛花猕猴桃果实中Vc含量极高,为了揭示毛花猕猴桃Vc形成规律,根据已知植物的L-半乳糖内酯脱氢酶(GalLDH)基因,设计简并引物,以毛花猕猴桃新品种‘华特'果实为材料提取总RNA,采用RT-PCR法,克隆出一条长661 bp的cDNA片段,根据测序结果推测其氨基酸序列,并与刺梨、拟南芥、甘薯和草莓等植物的GalLDH基因编码的氨基酸序列进行亲缘分析.结果表明,所克隆片段编码氨基酸序列与美味猕猴桃GalLDH相似度高达99%,其在同源基因进化关系上聚为一类,与葡萄的GalLDH相似性高达91%,与草莓、刺梨、甘薯、温州蜜柑、拟南芥、甜瓜等植物的GalLDH同源性均在80%以上,可知克隆到的核苷酸片段确为毛花猕猴桃GalLDH基因的cDNA片段.