《植物生理学报》 2016, 52(11): 1692-1702

光呼吸的功能及其平衡调控

张智胜^1,2, 彭新湘^1,*

¹华南农业大学生命科学学院亚热带农业生物资源保护与利用国家重点实验室, 广州510642; ²湖南农业大学生物科学技术学院, 长沙410128

通信作者：彭新湘；E-mail: xpeng@scau.edu.cn

摘　要：

植物光呼吸代谢是一条复杂的代谢途径, 是仅次于光合作用的第二大代谢流。它以闭路循环流动方式为主, 应对环境变化时也可能开放式运转; 所流经及惠及的细胞区域也最广, 涉及叶绿体、过氧化物体、线粒体、细胞质4种细胞器或区域。光呼吸不仅对C₃植物不可或缺, 对C₄植物也至关重要。光呼吸涉及多种生理功能, 包括调控光合作用、H₂O₂信号发生、氮素同化、一碳代谢, 防止光抑制光氧化, 适应生物与非生物胁迫等功能。因为光呼吸行使各种功能时的作用机制不同, 植物必须通过一套严密的环境信号响应及实时动态调控机制来实现对各种功能的平衡, 特别是那些在作用机理上“拮抗”或相互制约的功能, 以期最终实现光呼吸功能的最大发挥。综上所述, 由于光呼吸的复杂性, 尤其是在目前对光呼吸代谢网络的调控机制还知之甚少的情况下, 对光呼吸途径的代谢工程改造所能产生的作用也最好持一种谨慎乐观的态度。

关键词：光呼吸; 多功能; 平衡调控

收稿：2016-08-02   修定：2016-10-22

资助：国家自然科学基金(31470343和31600193)、广州市科技计划项目(201607020006)和湖南农业大学引进人才科研启动费项目(15YJ02)。

Multifunctional roles of photorespiration and its regulation for the balance

Zhang Zhi-Sheng^1,2, Peng Xin-Xiang^1,*

¹State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China; ²College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China

Corresponding author: Peng Xin-Xiang; E-mail: xpeng@scau.edu.cn

Abstract:

Photorespiration is a very complex metabolic pathway ranking the second highest metabolite flux in plants only after the photosynthetic carbon assimilation. It runs mainly through a closed cyclic system, but may also operate in an open way to cope with certain environmental stimuli or stresses. Its metabolic flow goes through and directly benefits very large area of the cell, including chloroplasts, peroxisomes, mitochondria and the cytosol. Photorespiration is not only essential for C₃ plants, but also important for C₄ plants. It plays multifunctional roles in plants, for instance, regulation of photosynthesis, H₂O₂ signaling genesis, nitrate assimilation and C₁ metabolism; protection against photoinhibition and photooxidation; adaptation to biotic and abiotic stresses. Since the mechanistic basis is different for various functions of photorespiration, to realize the functional balance, particularly for those with mutually “antagonistic” mechanisms, plants must have developed a suit of elaborate mechanisms of responding to environmental cues, and real-time and dynamically regulating photorespiration, aiming to finally realize the functional maximization. Taken together, due to the complexity of photorespiration, particularly as its regulatory mechanism is so far little understood, we should take cautiously optimistic attitude as to the benefits of any metabolic bioengineering on photorespiratory pathway.

Key words: photorespiration; multifunctional roles; regulation for balance