Hydrogen nanobubbles (NBs) have emerged as a novel strategy to enhance hydrogen solubility and retention in water, thus offering potential applications to aquatic ecosystems. However, their long-term biological effects and molecular mechanisms are unclear. This study provides the first comprehensive evaluation of the chronic effects of hydrogen NB water on the growth and reproduction of Daphnia magna (D. magna) under copper stress, uncovering key molecular pathways and pivotal genes. Over prolonged exposure, hydrogen NB water promoted the growth and reproduction in D. magna. Mechanistically, transcriptomic analysis revealed that hydrogen NB water promotes protein hydrolysis by upregulating carboxypeptidase A, boosting energy metabolism, and facilitating molting through the upregulation of Chitinase. In addition, hydrogen NB water attenuated retinol metabolism by upregulating retinol dehydrogenase, thereby influencing signal transduction pathways. In reproduction, hydrogen NB water significantly enhances prostaglandin synthesis by upregulating prostaglandin synthase and carbonyl reductase, improving energy homeostasis and reproductive capacity. These results not only highlight the molecular basis for the enhanced growth and reproduction of hydrogen NB water and provide a foundation for their application in improving pollutant stress in aquatic ecosystems. This study provides novel insights into the ecological role of hydrogen NB water and its implications for the sustainable management and restoration of aquatic ecosystems.

中文翻译：

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长期暴露于氢纳米气泡可增强溞对铜胁迫的恢复力：生长、繁殖和水生健康的可持续分子策略

氢纳米气泡 （NBs） 已成为一种提高氢在水中的溶解度和保留率的新策略，从而为水生生态系统提供了潜在的应用。然而，它们的长期生物学效应和分子机制尚不清楚。本研究首次全面评价了氢 NB 水对铜胁迫下溞 （D. magna） 生长和繁殖的慢性影响，揭示了关键的分子途径和关键基因。长时间暴露后，氢 NB 水促进了 D. magna 的生长和繁殖。从机制上讲，转录组学分析显示，氢 NB 水通过上调羧肽酶 A 促进蛋白质水解，促进能量代谢，并通过上调几丁质酶促进蜕皮。此外，氢 NB 水通过上调视黄醇脱氢酶来减弱视黄醇代谢，从而影响信号转导途径。在生殖中，氢 NB 水通过上调前列腺素合酶和羰基还原酶 ，改善能量稳态和生殖能力，显着增强前列腺素合成。这些结果不仅突出了氢 NB 水促进生长和繁殖的分子基础，并为它们在改善水生生态系统污染胁迫中的应用提供了基础。这项研究为氢 NB 水的生态作用及其对水生生态系统可持续管理和恢复的影响提供了新的见解。