Distinct roles of alternative oxidase pathway during the greening process of etiolated algae  

作　　者：Ying Liu Hua Zhang Yan Cui Yanli Zheng Hui Chen Zhangli Hu Qingyu Wu 

机构地区：[1]College of Life Sciences and Oceanography,Shenzhen University,Shenzhen 518055,China [2]Shenzhen Academy of Environmental Science,Shenzhen 518001,China [3]Gansu Innovation Center of Microalgae Technology,Hexi University,Zhangye 734000,China [4]Key Laboratory of Algal Biology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China [5]University of the Chinese Academy of Sciences,Beijing 100039,China [6]State Key Laboratory of Crop Stress Adaptation and Improvement,School of Life Sciences,Henan University,Kaifeng 475004,China

出　　处：《Science China(Life Sciences)》2021年第5期816-827,共12页中国科学（生命科学英文版）

基　　金：the National Key Research and Development Project for Synthetic Biology (2018YFA0902500);the National Natural Science Foundation of China (41876188);Shenzhen Grant Plan for Science and Technology (Shenzhen Basic Research Projects: JCYJ20180507182405562);Grant Plan for Demonstration Project for Marine Economic Development in Shenzhen to Dr. Zhangli HU。

摘　　要：The vital function of mitochondrial alternative oxidase(AOX) pathway in optimizing photosynthesis during plant de-etiolation has been well recognized. However, whether and how AOX impacts the chloroplast biogenesis in algal cells remains unclear. In the present study, the role of AOX in regulating the reassembly of chloroplast in algal cells was investigated by treating Auxenochlorella protothecoides with salicylhydroxamic acid(SHAM), the specific inhibitor to AOX, in the heterotrophy to autotrophy transition process. Several lines of evidences including delayed chlorophyll accumulation, lagged reorganization of chloroplast structure, altered PSI/PSII stoichiometry, and declined photosynthetic activities in SHAM treated cells indicated that the impairment in AOX activity dramatically hindered the development of functioning chloroplast in algal cells. Besides, the cellular ROS levels and activities of antioxidant enzymes were increased by SHAM treatment, and the perturbation on the balance of NAD+/NADH and NADP+/NADPH ratios was also observed in A. protothecoides lacking AOX activity, indicating that AOX was essential in promoting ROS scavenging and keeping the redox homeostasis for algal chloroplast development during greening. Overall, our study revealed the essentiality of mitochondrial AOX pathway in sustaining algal photosynthetic performance and provided novel insights into the physiological roles of AOX on the biogenesis of photosynthetic organelle in algae.

关 键 词：alternative oxidase pathway chloroplast reconstruction GREENING MICROALGAE reactive oxygen species redox 

分 类 号：Q945[生物学—植物学]