Mechanisms of Plant Responses to Waterlogging‐Induced Hypoxia: Integrated Regulatory Reprogramming for Survival and Recovery

Waterlogging is a serious abiotic stress caused by climate change that negatively affects plant growth and productivity. In response to waterlogging, plants activate a coordinated series of physiological, metabolic and molecular adjustments that maintain cellular homoeostasis and support survival. This review synthesises recent advances in the mechanisms by which waterlogging-induced oxygen deprivation is sensed and transduced into coordinated molecular programmes that determine plant survival and stress recovery. Particular attention is given to oxygen-sensing hubs centred on ethylene response factor group VII, which are regulated by the N-end rule/N-degron pathway and activate downstream stress-response programmes. Additionally, metabolic reprogramming under hypoxia, including the shift from aerobic respiration to anaerobic pathways (e.g., lactate and ethanolic fermentation) that sustain ATP production, is further examined. Furthermore, redox regulation during hypoxia-reoxygenation is discussed, highlighting the dynamics of reactive oxygen species, antioxidant defences, heat shock protein networks, and proteostasis mechanisms that constrain metabolic flux. Moreover, hormone-mediated growth-survival decisions, contrasting adaptive strategies, such as gibberellic acid-DELLA-mediated growth restraint and ethylene-driven gibberellic acid-abscisic acid signalling, are discussed. Building on this foundation, we present an integrative framework linking these regulatory layers into a coordinated system and compare its deployment across species to explain divergent tolerance outcomes. Finally, we translate these mechanisms into applied crop improvement, addressing breeding targets, ideotype design and field management, and identify key regulatory nodes and priority directions for advancing waterlogging tolerance.