Drought Stress Mediated Changes in Food Crops: Mechanisms and Remediation Strategies.

Climate change has intensified drought frequency and severity, threatening global food security, particularly for staple crops like maize, wheat, and soybean. As central secondary metabolites, flavonoids orchestrate cellular redox homeostasis, stress signal transduction, and metabolic plasticity during plant drought responses. Previous reviews are confined to isolated molecular cascades and separate treatment of flavonoid metabolism, rhizosphere microecology, and agronomic mitigation strategies, failing to establish an integrated multi-scale regulatory framework. To fill this fragmented gap, this review integrates advances in plant physiology, microbial ecology, and nanobiotechnology to construct a cross-scale framework of flavonoid-mediated drought resistance in major food crops. We systematically summarize species-specific flavonoid regulatory networks and metabolic reprogramming triggered by drought-induced oxidative stress, dissect rhizosphere microbiome effects on flavonoid biosynthesis and drought signaling, and elaborate novel mechanisms whereby nanomaterials reshape flavonoid metabolism and boost drought tolerance via tuning ROS homeostasis. Furthermore, this work integrates soil amendment and precision irrigation to decipher synergistic drought-resistance crosstalk among agronomic practices, crop metabolism, and root-associated microbiota. Collectively, this review unifies molecular, microbial, technological, and agronomic perspectives to establish a multi-scale, interdisciplinary framework for crop drought adaptation. It delivers fundamental theoretical support for climate-resilient agriculture and outlines priority research avenues to safeguard global food security.