Ostendarp Malte, de Breuyn Mareike, El-Khaled Yusuf C, Garcias-Bonet Neus, Carvalho Susana, Peixoto Raquel S, Wild Christian
Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, Bremen, Germany.
Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
PLoS One. 2025 Mar 25;20(3):e0308894. doi: 10.1371/journal.pone.0308894. eCollection 2025.
Coral reefs are increasingly threatened by mass bleaching events due to global ocean warming. Novel management strategies are urgently needed to support coral survival until global efforts can mitigate ocean warming. Given the strong antioxidant, anti-inflammatory and anti-apoptotic properties of molecular hydrogen, our study explores its potential to alleviate the negative effects of heat stress on corals. We investigated the ecophysiological responses of two common hard corals (Acropora sp. and Pocillopora verrucosa) from the Central Red Sea under ambient (26 °C) and elevated seawater temperatures (32 °C), with and without hydrogen addition ( ~ 150 µ M H2) over 48 h. Our results showed that at 32 °C without hydrogen addition, P. verrucosa exhibited high temperature tolerance, whereas Acropora sp. showed significant reductions in photosynthetic efficiency and maximum electron transport rate compared to the ambient condition (26 °C). The addition of hydrogen at 32 °C increased the maximum electron transport rate of Acropora sp. by 28%, maintaining it at levels compared to those at 26 °C. In contrast, the addition of hydrogen at 26 °C caused a significant decrease in the photophysiology of both Acropora sp. and P. verrucosa. This suggests that the short-term response of the coral holobiont to molecular hydrogen is temperature-dependent, potentially benefiting the coral holobiont under heat stress, while impairing the photophysiology under ambient temperatures. Our findings therefore provide the foundation for future long-term studies uncovering the mechanisms behind molecular hydrogen, potentially informing the development of new management strategies to enhance coral resilience to ocean warming.
由于全球海洋变暖，珊瑚礁正日益受到大规模白化事件的威胁。在全球努力缓解海洋变暖之前，迫切需要新的管理策略来支持珊瑚的生存。鉴于分子氢具有强大的抗氧化、抗炎和抗凋亡特性，我们的研究探索了其减轻热应激对珊瑚负面影响的潜力。我们研究了来自红海中部的两种常见硬珊瑚（鹿角珊瑚属和疣状杯形珊瑚）在环境温度（26°C）和升高的海水温度（32°C）下，添加和不添加氢气（约150μM H2）持续48小时的生态生理反应。我们的结果表明，在32°C且不添加氢气的情况下，疣状杯形珊瑚表现出耐高温性，而鹿角珊瑚属与环境温度（26°C）相比，光合效率和最大电子传递速率显著降低。在32°C添加氢气使鹿角珊瑚属的最大电子传递速率提高了28%，使其维持在与26°C时相当的水平。相比之下，在26°C添加氢气导致鹿角珊瑚属和疣状杯形珊瑚的光生理显著下降。这表明珊瑚共生体对分子氢的短期反应取决于温度，在热应激下可能使珊瑚共生体受益，而在环境温度下会损害光生理。因此，我们的研究结果为未来长期研究揭示分子氢背后的机制奠定了基础，可能为制定新的管理策略提供信息，以增强珊瑚对海洋变暖的恢复力。
