Xin Zhaojun, Zhang Jin, Ge Lingang, Lei Shu, Han Juanjuan, Zhang Xin, Li Xiwang, Sun Xiaoling
Tea Research Institute of Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Biology and Resource Utilization of Ministry of Agriculture, Hangzhou 310008, China.
Tea Research Institute of Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Biology and Resource Utilization of Ministry of Agriculture, Hangzhou 310008, China.
Gene. 2017 Jun 5;615:18-24. doi: 10.1016/j.gene.2017.03.013. Epub 2017 Mar 16.
12-Oxophytodienoate reductase (OPR) is a key enzyme in the biosynthesis of jasmonic acid (JA), which plays an important role in plant defense responses. Although multiple isoforms of OPRs have been identified in various annual herbaceous plants, genes encoding these enzymes in perennial woody plants have yet to be fully investigated. In the tea plant, Camellia sinensis (L.), no OPR genes have been isolated, and their possible roles in tea plant development and defense mechanism remain unknown. In this study, a putative OPR gene, designated as CsOPR3, was isolated from tea plants for the first time through the rapid amplification of cDNA ends. The open reading frame of CsOPR3 is 1197bp in length, and encodes a protein of 398 amino acids. Real-time qPCR analysis revealed that CsOPR3 was expressed in different organs. In particular, CsOPR3 was highly expressed in flowers, leaves and stems but was weakly expressed in roots and seeds. CsOPR3 expression could be rapidly induced by mechanical wounding, and increased JA levels were correlated with the wound-induced CsOPR3 expression. The infestation of the tea geometrid (TG) Ectropis obliqua Prout, regurgitant derived from TG and exogenous JA application could enhance the CsOPR3 expression. Our study is the first to report that CsOPR3 plays an important role in JA biosynthesis and tea plant defense against herbivorous insects.
12-氧代植物二烯酸还原酶（OPR）是茉莉酸（JA）生物合成中的关键酶，在植物防御反应中起重要作用。尽管在各种一年生草本植物中已鉴定出多种OPR同工型，但多年生木本植物中编码这些酶的基因尚未得到充分研究。在茶树（Camellia sinensis (L.)）中，尚未分离出OPR基因，其在茶树发育和防御机制中的可能作用仍然未知。在本研究中，首次通过cDNA末端快速扩增从茶树中分离出一个假定的OPR基因，命名为CsOPR3。CsOPR3的开放阅读框长度为1197bp，编码一个由398个氨基酸组成的蛋白质。实时定量PCR分析表明，CsOPR3在不同器官中表达。特别是，CsOPR3在花、叶和茎中高表达，但在根和种子中弱表达。CsOPR3的表达可被机械损伤快速诱导，JA水平的升高与伤口诱导的CsOPR3表达相关。茶尺蠖（TG）（Ectropis obliqua Prout）的侵害、TG的回流物和外源JA的施用均可增强CsOPR3的表达。我们的研究首次报道CsOPR3在JA生物合成和茶树对食草昆虫的防御中起重要作用。
