吴琼　方吴云　王文杰

摘要 [目的]明确机械损伤对不同茶树无性系品种叶片和新梢苯丙氨酸解氨酶（PAL）活性及茶多酚含量的影响。[方法]以茶树无性系良种舒茶早、凫早2号、福鼎大白茶为试验材料，采用分光光度计法测定正常茶树叶片中PAL活性和茶多酚含量变化的月节律，以及机械损伤诱导叶片和新梢PAL活性和茶多酚含量的时序变化。[结果]各品种未做任何损伤处理时，PAL酶活之间无明显差异，机械损伤1 h后，不论是轻修剪还是重修剪，3个品种间的PAL酶活均差异极显著；机械损伤对茶多酚含量的影响较PAL酶活有时间上的延迟；机械损伤对茶树新梢的PAL酶活和茶多酚含量有一定的影响，并且对不同品种的影响不同。[结论]试验结果为进一步探讨机械损伤对茶树生长和抗逆性的影响及其生理生化应答机理提供了参考。

关键词 茶树；机械损伤；PAL酶；茶多酚

中图分类号 S571.1 文献标识码 A 文章编号 0517-6611（2016）05-011-04

Abstract[Objective]The aim was to determine effects of mechanical wounding on PAL activity and tea polyphenol of leaves and new branch of different tree plants.[Method]By using Shu Chazao， Fuzao 2 and Fuding Dabai tea as test materials， adopting spectrophotometer method， PAL activity and content of tea polyphenol of normal tea plant and mechanical wounding leaves and new branch were measured[Result]The result showed there was no significant difference in PAL activity between 3 varieties without any damage. In 1h after mechanical damage， difference is significant at the 0.01. Compared with PAL activity， the amount of polyphenol changed later. The PAL activity and the amount of polyphenol in new shoots was influenced by mechanical damage， and it was different in different varieties.[Conclusion]The experiment results provide reference for further discussing effects of mechanical wounding on tea plant growth and resistance， as well as physiological growth response mechanism.

Key words Tea plant； Mechanical wounding； Phenylananine ammonialyase； Tea polyphenol

植物遭受机械损伤后产生一系列次生代谢物质如酚类、黄酮类、萜类、生物碱等，集中在伤口及其附近部位，参与伤愈合反应和抵抗昆虫或病菌的入侵[1]。这些次生代谢物质主要通过苯丙烷类代谢途径生成，苯丙氨酸解氨酶（Phenylananine ammonialyase，PAL，EC4.3.1.5）是催化这一途径的关键酶，在植物生长发育、防紫外辐射、抵御病虫害和构成植物支撑系统等方面具有重要的意义和价值，其活性可以作为衡量植物抗逆性强弱的指标[2]。由于酚类物质在植物抗生物胁迫机制中起着重要作用，PAL又被视为重要的防御酶，机械损伤也被认为是诱导植物防御的重要手段之一[3]。……