CAS and Shandong Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China.
CAS and Shandong Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Aoshanwei Town, Jimo, Qingdao 266237, China.
Mar Pollut Bull. 2023 Jul;192:115043. doi: 10.1016/j.marpolbul.2023.115043. Epub 2023 May 16.
Heat stress threatens the survival of seagrass, but its damage mechanisms are unclear. In this study, the results reveal that heat stress exceeding 36 °C in the dark caused inactivation of the PSII reaction center, damaging both the PSII donor and acceptor sides in Enhalus acoroides. High light further increased the damage to the photosynthetic apparatus under heat stress. The stronger the heat stress under high light, the harder the recovery of photosynthetic activity. Therefore, during ebb tide at noon in nature, heat stress combined with strong light would induce a significant, even irreversible decrease in photosynthetic activity. Moreover, the heat stress hindered the transcription of psbA and RuBisCO, enhanced respiratory O, and induced severe peroxidation even if the SOD, APX, and GPX activities significantly improved. The results clearly suggest that heat stress, especially when coupled with high light, may be an important cause for the decline of E. acoroides meadows.
热应激威胁着海草的生存，但它的损伤机制尚不清楚。在这项研究中，结果表明，在黑暗中超过 36°C 的热应激会导致 PSII 反应中心失活，从而损伤了海菖蒲中的 PSII 供体和受体侧。高光进一步增加了热应激下对光合作用器官的损伤。在高光下，热应激越强，光合作用活性的恢复就越困难。因此，在自然条件下的退潮中午时分，热应激与强光结合会导致光合作用活性显著下降，甚至是不可逆转的下降。此外，热应激会抑制 psbA 和 RuBisCO 的转录，增强呼吸 O，并导致严重的过氧化，即使 SOD、APX 和 GPX 的活性显著提高。研究结果清楚地表明，热应激，尤其是与高光结合时，可能是海菖蒲草地减少的一个重要原因。
