高温和干旱胁迫下茶树叶片内源激素含量变化及其相关基因的表达分析  

Changes of Endogenous Hormone Contents and Expression Analysis of Related Genes in Leaves of Tea Plants Under Heat and Drought Stresses

作　　者：唐子贻 杜玥 杨宏斌 黎星辉[2] 余有本[1] 王伟东[1] TANG Ziyi;DU Yue;YANG Hongbin;LI Xinghui;YU Youben;WANG Weidong(College of Horticulture,Northwest A&F University,Yangling 712100,China;College of Horticulture,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]西北农林科技大学园艺学院,陕西杨凌712100 [2]南京农业大学园艺学院,江苏南京210095

出　　处：《茶叶科学》2023年第4期489-500,共12页Journal of Tea Science

基　　金：陕西省重点研发计划项目(2022NY-154);陕西省农业专项资金项目[NYKJ-2022-YL(XN)37];国家茶叶产业技术体系(CARS-19);西北农林科技大学科技推广重点项目(TGZX2022-2)。

摘　　要：高温干旱极端环境严重影响茶树生长发育,以及茶叶产量和品质,激素作为植物响应逆境胁迫的重要信号因子,其在茶树响应高温和干旱胁迫过程中的分子机理少有报道。以龙井长叶为材料,对高温和干旱胁迫下茶树叶片中内源激素含量的变化及其相关基因的表达水平进行了系统分析。结果表明,高温和干旱胁迫下茶树叶片中生长素(IAA)、赤霉素(GA_(3))含量显著降低,玉米素核苷(ZR)含量略有升高,推测茶树通过减少促生类激素来延缓生长以适应胁迫影响;同时,大量IAA、GA_(3)、ZR生物合成和信号响应相关的基因显著差异表达,为解释激素含量变化及信号转导提供了分子基础。脱落酸(ABA)和茉莉酸(JA)作为逆境响应激素其含量在高温和干旱胁迫下均显著增加,这可能依赖于ZEP、NCED、SDR等ABA生物合成途径基因和LOX、OPR、ACX等JA生物合成途径基因的上调表达;另外,许多PYR/PYL、PP2C等ABA信号途径基因以及JAZ、MYC2等JA信号途径基因也显著差异表达,暗示了ABA和JA信号途径在茶树响应高温和干旱胁迫过程中的重要作用。研究结果为进一步探究茶树依赖内源激素的高温和干旱胁迫响应分子机理提供理论参考。Extreme environments,such as heat and drought,seriously affect the growth and development of tea plants and the quality of tea production.Hormones are important signaling factors,but the molecular mechanisms of hormones involved in the response of tea plants to heat and drought stresses are rarely reported.In this study,we systematically analyzed the changes in endogenous hormone contents and the expression levels of related genes in leaves of tea plants under heat and drought stresses.The results show that the contents of IAA and GA_(3)were significantly reduced and the contents of ZR were slightly increased in leaves of tea plants under heat and drought stresses,which were presumably used to delay the growth of tea plants to adapt to the environment stresses.Meanwhile,many genes related to biosynthesis and signal response of IAA,GA_(3)and ZR were significantly differentially expressed,which provided a molecular basis for explaining the hormone content changes and signal transduction.In addition,the contents of ABA and JA increased significantly under both heat and drought stresses,which may depend on the up-regulated expressions of ABA biosynthetic pathway genes such as ZEP,NCED,SDR and JA biosynthetic pathway genes such as LOX,OPR,ACX.Furthermore,many ABA signal responsive genes such as PYR/PYL,PP2C and JA signal responsive genes such as JAZ,MYC2 were also significantly differentially expressed,suggesting the important role of ABA and JA signaling pathways in the response of tea plants to heat and drought stresses.These results provided theoretical references for further exploring the molecular mechanisms of tea plants response to heat and drought stresses,which rely on endogenous hormones.

关 键 词：茶树 内源激素 脱落酸 茉莉酸 基因表达分析 非生物胁迫 

分 类 号：S571.1[农业科学—茶叶生产加工]