ZmCRK5A kinase enhances drought tolerance in maize via phosphorylation‐dependent inhibition of ZmSMH4

Channel 1). Functional validation revealed that ZmKCH1 overexpression confers drought resilience through optimized stomatal dynamics and water retention, whereas clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-generated zmkch1 mutants display hypersensitivity to water deficit. Crucially, field evaluations demonstrated preserved grain yield alongside enhanced drought tolerance in plants with activated ZmCRK5A-ZmSMH4-ZmKCH1 signaling. Our findings delineate a kinase-transcription factor-ion channel axis that dynamically fine-tunes drought responses while maintaining productivity, providing a strategic framework for engineering stress-adapted crops without yield penalties.