Zhang Xiaohua, Gao Guang, Gao Zhengquan, Gao Kunshan, Liu Dongyan
School of Pharmacy, Binzhou Medical University, Yantai, 264003 China.
State Key Laboratory of Marine Environmental Science, Xiamen University (Xiang'an Campus), Xiamen, 361102 China.
Mar Life Sci Technol. 2024 Dec 12;7(3):537-548. doi: 10.1007/s42995-024-00265-7. eCollection 2025 Aug.
CO concentration mechanisms (CCMs) are important in maintaining the high efficiency of photosynthesis of marine algae. Aquatic photoautotrophs have two types of CCMs: biophysical CCMs, based on the conversion of inorganic carbon, and biochemical CCMs, based on the formation of C acid intermediates. However, the contribution of biophysical and biochemical CCMs to algal carbon fixation remains unclear. Here, we used ethoxyzolamide (EZ) inhibitors of carbonic anhydrase and 3-mercaptopicolinic acid (MPA) inhibitors for phosphoenolpyruvate carboxykinase to examine the importance of biophysical and biochemical CCMs in photosynthesis of the green macroalga . The culture experiments showed that the carbon fixation of the species declined when EZ inhibited the biophysical CCM, while the increase in cyclic electron flow around the photosystem I indicated a more active biochemical CCM, contributing to ~ 50% of total carbon fixation. The biophysical CCM was also reinforced when MPA inhibited the biochemical CCM. In a comparison, the biophysical CCM can compensate for almost 100% of total carbon fixation. The results indicate that biophysical CCMs dominate the process of carbon fixation of while biochemical CCM plays a supporting role. Our results provide evidence of a complementary coordination mechanism between the biophysical and biochemical CCMs that promotes the efficiency of photosynthesis of , an efficient mechanism to boost the alga's bloom.
The online version contains supplementary material available at 10.1007/s42995-024-00265-7.
二氧化碳浓缩机制（CCMs）对于维持海藻光合作用的高效率至关重要。水生光合自养生物有两种类型的CCMs：基于无机碳转化的生物物理CCMs和基于C酸中间体形成的生化CCMs。然而，生物物理和生化CCMs对藻类碳固定的贡献仍不清楚。在这里，我们使用碳酸酐酶的乙氧唑胺（EZ）抑制剂和磷酸烯醇丙酮酸羧激酶的3-巯基吡啶酸（MPA）抑制剂来研究生物物理和生化CCMs在绿色大型海藻光合作用中的重要性。培养实验表明，当EZ抑制生物物理CCM时，该物种的碳固定下降，而围绕光系统I的循环电子流增加表明生化CCM更活跃，对总碳固定的贡献约为50%。当MPA抑制生化CCM时，生物物理CCM也得到增强。相比之下，生物物理CCM几乎可以补偿100%的总碳固定。结果表明，生物物理CCMs在碳固定过程中占主导地位，而生化CCM起辅助作用。我们的结果提供了生物物理和生化CCMs之间互补协调机制的证据，该机制促进了光合作用的效率，这是促进藻类大量繁殖的有效机制。
在线版本包含可在10.1007/s42995-024-00265-7获取的补充材料。
