浙江农业学报

• 园艺科学 • 上一篇    下一篇

外源24表油菜素内酯诱导茶树(Camellia sinensis L.)耐热性的生理机制

  

  1. (1.中国农业科学院 茶叶研究所,浙江 杭州310008; 2.中国农业科学院 研究生院,北京 100081)
  • 出版日期:2016-06-25 发布日期:2016-06-12

Physiology mechanism of exogenous 24epibrassinolideinduced heat resistance in tea plants(Camellia sinensis L.)

  1. (1.Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; 2.Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China)
  • Online:2016-06-25 Published:2016-06-12

摘要: 以茶树品种龙井43为试验材料,研究外源24表油菜素内酯(EBR)处理对高温胁迫下茶树叶片光合特性、叶绿素荧光参数、丙二醛(MDA)含量和抗氧化酶活性的影响。研究发现:叶面喷施EBR能显著提高高温胁迫下茶树叶片的净光合速率(Pn),气孔导度(Gs),Rubisco最大羧化速率(Vc,max)、Rubisco的最大再生速率(Jmax)和PSⅡ最大光化学效率(Fv/Fm);同时外源EBR处理后,高温胁迫下茶树叶片中的抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性显著提高,而MDA含量则显著下降。外源EBR主要通过解除非气孔因素的限制、促进光合碳反应的进行来缓解高温胁迫对茶树叶片光合作用的抑制;同时EBR能够有效利用多种抗氧化途径以清除其细胞内的自由基和活性氧,最终缓解高温胁迫对茶树的伤害。

关键词: 茶树, 高温, 油菜素内酯, 光合特性, 抗氧化酶

Abstract: The present study investigated the effects of exogenous 24epibrassinolide (EBR) on gas exchange, chlorophyll fluorescence parameters, lipid peroxidation (MDA content) and antioxidant enzymes activities in tea (Camellia sinensis cv. Longjing 43) leaves under heat stress. Results showed that foliar application of EBR could significantly increase Pn, Gs, Vc,max, Jmax and Fv/Fm in tea leaves under heat stress. Moreover, EBR remarkably increased activities of APX, CAT, SOD and POD, but decreased MDA content in tea leaves following heat stress. These results suggest that exogenous EBR mitigates heat stressinduced photosynthetic inhibitions in tea leaves, mainly by eliminating the nonstomatal limitations and promoting the photosynthetic carbon reaction. Furthermore, EBR strengthened the antioxidant system effectively to scavenge harmful levels of reactive oxygen species and thus alleviated heat stress in tea plant.

Key words: Camellia sinensis L., heat stress, EBR, photosynthetic characteristics, antioxidant enzymes