草莓果实多酚氧化酶基因的克隆及序列分析

Cloning and Analysis of Polyphenol Oxidase Gene in Strawberry

多酚氧化酶(polyphenol oxidase,PPO)是一类植物体内广泛存在的由核基因编码的能与铜结合的金属蛋白酶。它是诱导许多果蔬等农产品产生酶促褐变的主要原因,同时在植物的生长发育、抗病虫害及果实品质形成等方面也起到了一定的作用。本文用RACE的方法,从草莓幼果cDNA中成功扩增出PPO基因的3'端部分序列。序列分析表明该基因片段编码424个氨基酸。与其他物种PPO核苷酸序列比较相似性为72%～80%,氨基酸相似性为82%～87%。草莓多酚氧化酶基因的成功克隆,为草莓抗褐变的研究及果实品质的改良打下了坚实的理论基础。

Polyphenol oxidase （PPO） is a ubiquitous metal protein which is encoded by nuclear genes and can be combine with copper in many plant species. It is the primary cause of enzymatic browning of many fruits and vegetables and is thought to be involved in plant growth, pest resistance, the formation of fruit quality and so on. By using RACE method, 3′ flanking sequences ofPPO gene was amplified from cDNA of young fruit of strawberry. Sequences analysis shows that this fragment encodes 424 amino acids. Homology analysis shows that it has 72%- 80% similarity in nucleotides and 82%-87% similarities in amino acids when compared with others species. The successful cloning of PPO gene from strawberry builds a solid theoretical foundation for the research of strawberry browning resistance and improvement of fruit quality.