The enhancement of the oxidative pentose phosphate pathway maybe involved in resolving imbalance between photosystem I and II in Dunaliella salina
The enhancement of the oxidative pentose phosphate pathway maybe involved in resolving imbalance between photosystem I and II in Dunaliella salina
复制标题
氧化戊糖磷酸途径的增强可能参与解决盐藻光系统I和II之间的不平衡
DOI：
10.1016/j.algal.2017.07.024
复制
发表时间：
2017
影响因子：
5.1
通讯作者：
Wang Guangce
中科院分区：
文献类型：
--
作者：
Zheng Zhenbing;Gao Shan;He Yuan;Li Zhuangyue;Li Yuanxiang;Cai Xuehua;Gu Wenhui;Wang Guangce
杜氏盐藻（Dunaliella salina）是一种单细胞绿色植物，由于其耐盐性和生产β-胡萝卜素的经济价值而被广泛研究。盐胁迫下，盐藻合成甘油调节细胞内渗透压。为了揭示这一过程中电子和还原力的分配模式，研究了盐胁迫下光合性能和氧化戊糖磷酸途径（OPPP）的运作。当D时，甘油大量积累。盐碱地受到盐胁迫。同时，光系统II（PSII）活性增加，而光系统I（PSI）活性下降。这表明PSII中产生的一小部分电子被泄漏并被转移以产生活性氧（ROS），而大多数电子随后被用于PSI以产生ATP和NADPH。此外，对OPPP进行了强化，为甘油合成提供还原力和碳骨架。综上所述，盐胁迫下，盐地碱蓬PSII和PSI之间的光合电子分配失衡，导致甘油合成所需的NADPH和ATP不足，从而导致OPPP和ROS的产生增加。
Dunaliella salina is a unicellular green alga extensively studied due to its capability of salt stress tolerance and high economic value forβ-carotene production. Glycerol is synthesized to regulate intracellular osmotic pressure during salt stress inD. salina. In order to demonstrate the electron and reducing power distribution pattern in this process, photosynthetic performance and oxidative pentose phosphate pathway (OPPP) operation during salt stress were investigated. Glycerol was accumulated massively whenD. salinawas subjected to salt stress. Meanwhile, photosystem II (PSII) activity was increased while photosystem I (PSI) activity was decreased. This suggests that a small portion of the electrons generated in PSII were leaked and were transferred to generate reactive oxygen species (ROS), while most electrons subsequently used to PSI to generate ATP and NADPH. Furthermore, the OPPP was enhanced in order to provide reducing power and carbon skeleton for glycerol synthesis. In conclusion, during salt stress, the imbalance of photosynthetic electron distribution between PSII and PSI inD. salinaresulted in a shortage of NADPH and ATP for glycerol biosynthesis, which also led the enhancement of the OPPP and ROS generation.