中文摘要：

从[木奈]（Prunus salicina Lindl.var.cordataJ.Y.Zhang et al.）成熟叶片均一化全长cDNA文库中新分离得到了1个PPO基因,命名为PsPPO2,基因登录号为JF681036.1。经NCBI-BLAST分析,其核苷酸序列与蔷薇科果树中的河北鸭梨和富士苹果果实的PPO基因具有很高的同源性,分别为81%和80%;与作者先前分离克隆的PsPPO1和PsPPO3基因同源性分别为55%和56%,说明此克隆是PPO基因家族的新成员。通过RT-PCR分析,PsPPO1、PsPPO2和PsPPO这3个基因在[木奈]不同生长发育时期和果实受损伤后的表达模式。在叶片发育过程中,PsPPO2表达量都很高;PsPPO1在嫩芽和幼叶中表达;PsPPO3只在嫩芽中表达;在果实发育的不同时期,PsPPO2和PsPPO3在早期表达,随着果实成熟表达量下降,PsPPO1在褐变果中表达量较高。受机械损伤后,PsPPO1受诱导,而PsPPO2和PsPPO3不受诱导。

英文摘要：

Polyphenol oxidase（PPO）has been regarded to be a critical enzyme in food technology.A new clone,named PsPPO2,was separated from cDNA library prepared from mature leaf of the Prunus salicina Lindl.var.cordata J.Y.Zhang et al.The deduced amino acid sequences shared 81%and 80% identity with the PPO from Hebei Yali pear and Fuji apple and shared 55%and 56%identity with the PPO gene from P.salicina leaf and fruit which previous isolated,respectively.RT-PCR showed that three PPO gene displayed unique patterns of expression in developmental specific manner in leaf and fruit tissue.In the process of leaf development,the PsPPO2 mRNA was detectable at all stages.In contrast,PsPPO1 and PsPPO3 were expressed in young tissue.PsPPO2 and PsPPO3 expression are higher at the early stages of fruit development,then dramatically reduced as the fruit ripened.The PsPPO1 mRNA was detectable only at the browning fruit.Upon wounding,PsPPO1 was significantly induced in mature fruit,whereas the level of PsPPO2 and PsPPO3 were not affected by mechanical damage.