衣藻二氧化碳浓缩机制及其调控的研究进展

Research Progress on the CO2 Concentrating Mechanism and Its Regulation in Chlamydomonas

当低浓度CO 2限制微藻光合作用时,CO 2浓缩机制(CCM)是一种有效的无机碳(Ci)吸收策略,以保证微藻的正常生存和繁殖。CCM主要是通过升高1,5-二磷酸核酮糖羧化酶/加氧酶(Rubisco)附近的CO 2浓度增强光合作用的效率,同时抑制光呼吸的进行。CCM的关键步骤包括无机碳的聚集吸收、Rubisco对CO 2的固定和碳酸酐酶催化的不同Ci的转换。CCM中分子调控元件的有序协作,不仅可以帮助细胞感知周围CO 2的浓度,诱导调节CCM基因的表达,还可以协调衣藻在低浓度CO 2环境下光合作用中碳和其他代谢途径的相互作用。总结了目前以衣藻作为模式生物对真核藻类CCM的研究概况、调控机理,以及CCM机制在农业方面的应用和展望。

CO 2 concentrating mechanism(CCM)is an effective way for carbon assimilation that enables microalgae to survive and proliferate in the limiting CO 2 concentration.CCM can improve the CO 2 concentration near the Rubisco to enhance the photosynthetic efficiency and suppress the photorespiration.The key components of CCM include inorganic carbon(Ci)uptake,Ci fixation by Rubisco and the interconversion of different Ci catalyzed by CA.An array of the molecular regulatory elements can facilitate cells to sense the CO 2 concentration,regulate the expression of the CCM and to coordinate the photosynthetic carbon metabolism and other metabolic processes in response to limiting CO 2 conditions.This review summarized the current understanding of the eukaryotic algal CCM,based largely on chlamydomonas as a model organism,to illustrate how chlamydomonas adapts to the limiting CO 2 and how its CCM was regulated.