Exploring Flooding Challenges, Causes, and Mitigation Strategies in Rice

Flooding is a dominant constraint to rice production in lowland and floodplain ecosystems, where stress intensity, timing, and duration vary widely across agroecological zones. This review synthesizes current knowledge on flooding typologies affecting rice, including anaerobic germination failure, flash flooding, stagnant flooding, and deep-water submergence, and critically examines how rice plants respond at physiological, anatomical, and molecular levels. We integrate evidence on key adaptive mechanisms, including anaerobic metabolism during germination, SUB1-mediated quiescence under short-term submergence, SNORKEL-driven internode elongation in deep-water environments, aerenchyma development, leaf gas films, and antioxidant defense systems. Particular emphasis is placed on the genetic architecture underpinning these responses, highlighting the successes and limitations of the SUB1 locus and the necessity of multitrait pyramiding to address prolonged, deep, or sequential flooding events. Drawing on case studies from Africa and Asia, the review demonstrates that flooding impacts are strongly context-specific, shaped by rainfall variability, hydrology, soil properties, and water management infrastructure, with disproportionate socioeconomic consequences for smallholder farmers. We argue that reliance on single-gene solutions is insufficient under climate change scenarios that intensify flood unpredictability. Instead, resilient rice systems require an integrated strategy combining stress-tolerant varieties, adaptive crop and nutrient management, and climate-informed decision-making. By consolidating physiological insights, breeding advances, and regional flood dynamics, this review provides a targeted framework for developing rice varieties and management options tailored to diverse flooding regimes, with direct implications for food security in flood-prone regions.