Cloning and Expression of a cDNA Encoding Endopolygalacturonase from Feicheng Peach (Prunus persica)   

肥城桃中多聚半乳糖醛酸酶基因的分离及其表达研究(英文)

作　　者：马庆虎[1] 王莉梅[1] 宋艳茹[1] 朱至清[1] 

机构地区：[1]中国科学院植物研究所

出　　处：《Acta Botanica Sinica》1999年第3期263-267,共5页Acta Botanica Sinica（植物学报：英文版）

摘　　要：Polygalacturonase (PG,EC3.2.1.15) is the key cell wall hydrolase in fruit ripening. The identification and characterization of a full length cDNA (pMT18) encoding for PG from Feicheng peach (Prunus persica (L.) Batsch cv. Feicheng) is described. The pMT18 clone is 1188 bp in length, with an open reading frame of 393 amino acids. The homology and phylogenetic analyses indicate a remarkable similarity between peach PG and other ripening related PG. And seven consensus sequences have revealed in peach PG compared to the PG from other plants. However, the profound divergence with other PG and the unique structure features suggest that peach PG probably belongs to a new evolutionary class. In RT PCR analysis, pMT18 related RNA was undetectable in leaves, and was much abundant in ripe fruits. The ripening specific expression pattern of this cDNA will be useful in investigating the roles of PG in fruit ripening and developing a transgenic peach with the improved post harvesting quality in the future.多聚半乳糖醛酸酶（ＥＣ３．２．１．１５）是一类在果实后熟中起重要作用的细胞壁水解酶。肥城桃（Ｐｒｕｎｕｓｐｅｒｓｉｃａ（Ｌ．）Ｂａｔｓｃｈｃｖ．Ｆｅｉｃｈｅｎｇ）是中国特产名贵水果。报道了从肥城桃中克隆和鉴定出的一个编码ＰＧ全长的ｃＤＮＡ（ｐＭＴ１８），此克隆长１１８８ｂｐ，包括一个３９３个氨基酸组成的开放阅读框架。比较肥城桃与其他植物的ＰＧ氨基酸序列，揭示出ＰＧ基因中具有７个比较保守的一致顺序。相似性及系统树分析表明，虽然桃中的ＰＧ与其他成熟相关的ＰＧ具有相当的相似性，但它们之间又存在比较远的进化距离，而且桃的ＰＧ在蛋白质结构上具有比较独特的特征，因此推测它可能属于进化上比较独特的类群。ＲＴＰＣＲ分析表明，肥城桃叶片中检测不到ＰＧ编码的ｍＲＮＡ，但在果实中其表达量却非常丰富。肥城桃ＰＧｃＤＮＡ在果实中特异表达的特性将有助于进一步研究其在果实成熟中的作用，并通过反义ＲＮＡ及转基因途径改善肥城桃的采后品质。

关 键 词：Prunus persica POLYGALACTURONASE CDNA Fruit ripening 

分 类 号：S662.101[农业科学—果树学]