As the global climate changes, the frequency and severity of flood disasters have increased significantly, seriously affecting agricultural production. Hydrogen sulfide (H₂S), as a gaseous signal molecule, plays an important role in plant development and stress adaptation. Previous studies suggested that H₂S acts as an oxygen sensor when animals experience hypoxia. However, the role of H₂S in the response and adaptation to flooding-induced hypoxia stress in plants is poorly understood. Here, we report that pretreatment with exogenous H₂S or Cys significantly improved tolerance to submergence in Arabidopsis. Total submergence of soil-grown Arabidopsis increased the levels of endogenous H₂S and its main endogenously generated product, cysteine (Cys) over time, and altered the expression of H₂S or Cys biosynthesis- or metabolism-related genes, implying that the H₂S-Cys homeostasis may contribute to regulation of tolerance to flooding. Transcriptomic and metabolomic analyses demonstrated that exogenous H₂S-pretreatment activated hypoxia-responsive transcription factors and hypoxia sensing-related genes in a timely manner and limited cellular activities associated with growth through regulation of hormonal signaling, but had less influence on transcripts associated with photosynthesis. H₂S-pretreatment also altered the levels of metabolites, particularly of amino acids and plant hormones, during submergence. Taken together, this study provides new insight into how H₂S regulates tolerance to submergence-induced hypoxia stress and lays the foundation to design new strategies for the improvement of submergence resistance in crops.

随着全球气候变化，洪水灾害的频率和严重性大大增加，严重影响了农业生产。硫化氢（H ₂ S）作为一种气态信号分子，在植物发育和逆境适应中起着重要作用。先前的研究表明，当动物经历缺氧时，H ₂ S会充当氧气传感器。但是，人们对H ₂ S在植物中对洪水诱导的缺氧胁迫的响应和适应中的作用了解甚少。在这里，我们报道用外源H ₂ S或Cys预处理显着提高了拟南芥对浸没的耐受性。土壤生长的拟南芥的完全浸没增加了内源性H ₂的水平S及其主要内生产物半胱氨酸（Cys）随时间推移，并改变了H ₂ S或Cys生物合成或代谢相关基因的表达，这暗示H ₂ S-Cys稳态可能有助于调节对洪水的耐受性。转录组学和代谢组学分析表明，外源H ₂ S预处理能够及时激活缺氧反应性转录因子和缺氧感测相关基因，并通过调节激素信号来限制与生长相关的细胞活动，但对与光合作用相关的转录物的影响较小。高₂S-预处理还可以在淹没期间改变代谢物的水平，尤其是氨基酸和植物激素的水平。两者合计，这项研究提供了新的见解H ₂ S如何调节对淹水诱导的缺氧胁迫的耐受性，并为设计新的策略来改善作物的抗淹水能力奠定了基础。