光呼吸研究进展

Research Advances in Photorespiration

摘要:

光呼吸是指植物绿色组织依赖光能吸收O₂并释放CO₂的过程，它被认为是一个浪费能量的过程。正常生长的C₃植物光呼吸可损耗光合产物的25%~30%，在干旱、高温、高光等逆境胁迫下，该损耗可高达50%，因此，显著提高C₃植物的生产力可通过减少光呼吸通量来实现。尽管光呼吸对植物生产力的负面影响明显，但它对植物一些必要生理活动可能起着重要作用，其中包括参与光保护、H₂O₂信号发生、氮代谢、光氧化和抗逆反应等。该文对光呼吸的改造优化需要把握好平衡点与适配度。基于Rubisco改造、CO₂浓缩机制(CCM)和光呼吸支路创建的光呼吸改造研究进展进行了综述。通过了解调控光呼吸提高植物光能转化效率方面的最新进展, 可望为光呼吸代谢的分子调控及改良研究提供指导。

Abstract:

Photorespiration is a process, in which plant green tissue absorbs O₂ and releases CO₂ depending on light energy, which is considered to be a waste of energy. Photorespiration of normally growing C₃ plants can lose 25%- 30% of photosynthate, and the loss can be as high as 50% under stresses, such as drought, high temperature and high light. Therefore, significantly improving the productivity of C₃ plants can be achieved by reducing photorespiration flux. Although photorespiration has obvious negative effects on plant productivity, it may play an important role in some essential physiological activities of plants, including participating in photoprotection, H₂O₂ signaling, nitrogen metabolism, photooxidation and stress response. Thus, the transformation and optimization of photorespiration need to grasp the balance point and adaptation. The photorespiration modification based on Rubisco modification, CO₂ concentration mechanism (CCM) and photorespiration branch creation was reviewed. By understanding the latest progress in the regulation of photorespiration to improve the efficiency of plant light conversion, it is expected to provide guidance for the studies on molecular regulation and improvement of photorespiration metabolism.