Wang Mengxin, Zhao Wei, Ma Mingyu, Zhang Di, Wen Yun, Zhong Mingyu, Luo Chengying, Hu Zimin, Zhang Quansheng
Ocean School, Yantai University, Yantai, China.
Front Plant Sci. 2022 Feb 25;13:792059. doi: 10.3389/fpls.2022.792059. eCollection 2022.
, a foundation species of the angiosperm-dominated marine blue carbon ecosystems, has been recognized to be a vulnerable seagrass. Its degradation has previously been reported to be associated with environmental changes and human activities, while there has been a limited number of studies on its inherent characteristics. In this study, both the physiological and molecular biological data indicated that the oxygen-evolving complex (OEC) of is prone to photoinactivation, which exhibits the light-dependent trait. When exposed to laboratory light intensities similar to typical midday conditions, <10% of the OEC was photoinactivated, and the remaining active OEC was sufficient to maintain normal photosynthetic activity. Moreover, the photoinactivated OEC could fully recover within the same day. However, under harsh light conditions, e.g., light intensities that simulate cloudless sunny neap tide days and continual sunny days, the OEC suffered irreversible photoinactivation, which subsequently resulted in damage to the photosystem II reaction centers and a reduction in the rate of O evolution. Furthermore, measurements on a cloudless sunny neap tide day revealed both poor resilience and irreversible photoinactivation of the OEC. Based on these findings, we postulated that the OEC dysfunction induced by ambient harsh light conditions could be an important inherent reason for the degradation of
作为被子植物主导的海洋蓝碳生态系统的基础物种，已被认定为一种脆弱的海草。此前有报道称其退化与环境变化和人类活动有关，而对其内在特性的研究数量有限。在本研究中，生理和分子生物学数据均表明，[海草名称]的放氧复合体（OEC）易于发生光失活，呈现出光依赖性特征。当暴露在与典型中午条件相似的实验室光照强度下时，<10%的OEC发生光失活，剩余的活性OEC足以维持正常的光合活性。此外，光失活的OEC可在同一天内完全恢复。然而，在强光条件下，例如模拟无云晴天小潮日和持续晴天的光照强度下，OEC遭受不可逆的光失活，随后导致光系统II反应中心受损以及放氧速率降低。此外，在无云晴天小潮日的[相关测量]显示OEC恢复能力差且存在不可逆的光失活。基于这些发现，我们推测环境强光条件诱导的OEC功能障碍可能是[海草名称]退化的一个重要内在原因
