Responses of photosystem II and antioxidative systems to high light and high temperature co-stress in wheat
Responses of photosystem II and antioxidative systems to high light and high temperature co-stress in wheat
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DOI：
10.1016/j.envexpbot.2016.12.001
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发表时间：
2017-03-01
影响因子：
5.7
通讯作者：
Yuan, Shu
中科院分区：
文献类型：
--
作者：
Chen, Yang-Er;Zhang, Chao-Ming;Yuan, Shu
近几十年来，高温长光暴晒的极端天气急剧增加，对植物的光合作用产生了显著影响。以小麦（Triticum aestivum L）为研究对象，研究了高温强光共胁迫对小麦光系统II （PSII）和抗氧化防御系统的影响。在高温和强光共胁迫下，PSII的叶绿素含量、相对含水量和光化学活性均下降。快速响应（共胁迫1 h）时，活性氧（ROS）水平、6种抗氧化酶活性、Lhcb5 （CP26）和Lhcb6 （CP24）蛋白水平显著升高。而CP26和CP24在单一强光或热胁迫下均未被快速诱导。此外，在交叉胁迫1 h下，Lhcb4 （CP29）和D2蛋白被强烈磷酸化，PSII-LHCII超复合物被明显分解。而在响应后期（共胁迫3 h）， 6种抗氧化酶中只有APX和GPX活性显著升高。同时，共胁迫3 h后，光合活性和D1、PsbQ水平显著降低。PsbQ的显著下降是在高光热共胁迫下所特有的。因此，我们认为高光热共胁迫具有协同效应，PSII在共胁迫下变化迅速而强烈。综上所述，调控PSII-LHCII复合体结构及其磷酸化状态可能对减轻小麦叶绿体在强光热胁迫下的光损伤具有重要意义。(C) 2016 Elsevier B.V.版权所有
In the past few decades, extreme weather conditions with high temperature and long light exposure increased dramatically, which significantly affect the photosynthesis of plants. In this study, the impacts of heat and high-light co-stress on Photosystem II (PSII) and antioxidant defense system were investigated in wheat (Triticum aestivum L). Under heat and high-light co-stress, chlorophyll content, relative water content, and photochemical activity of PSII decreased. For rapid responses (1 h of the co-stress), levels of reactive oxygen species (ROS), activities of six antioxidant enzymes, and protein levels of Lhcb5 (CP26) and Lhcb6 (CP24) increased significantly. However, the rapid induction of CP26 and CP24 did not be found under single high light or heat stress. In addition, the strong phosphorylation of Lhcb4 (CP29) and D2 proteins and an obvious disassembly of the PSII-LHCII supercomplexes were found under the cross-stress for 1 h. However for the late responses (3 h of co-stress), among the six antioxidant enzymes, only the activities of APX and GPX significantly increased. Meanwhile, the photosynthetic activity and the level of D1 and PsbQ significantly decreased after 3 h of co-stress. The remarkable decrease in PsbQ was unique under high light and heat co-stress. Therefore, we concluded that high light and heat co-stress had synergetic effect and PSII had the rapid and strong changes under co-stress. Taken together, the results show that regulations to PSII-LHCII complex structures and their phosphorylation statuses may be important for alleviating photo-damages to chloroplasts under high light and heat co stress in wheat. (C) 2016 Elsevier B.V. All rights reserved.