Drought stress memory in maize: understanding and harnessing the past for future resilience.

Abstract

Maize (Zea mays L.), a cornerstone of global food security, faces significant challenges due to drought stress, which disrupts its growth, development, and productivity. This review synthesizes advances in our understanding of drought stress memory, a mechanism that enables maize to "remember" prior drought exposure through transcriptional, epigenetic, and physiological pathways. Key regulators, including transcription factors (ZmEREB24 and ZmNF-YC12) and epigenetic modifications (DNA methylation and histone acetylation), orchestrate stress-responsive pathways that ensure rapid adaptation to recurrent drought events. Complementing these molecular mechanisms, physiological adaptations, such as optimized root and leaf architecture, enhanced water-use efficiency, and antioxidant defenses, further strengthen drought tolerance. Practical applications, including molecular priming techniques (e.g., osmopriming, hydropriming, nanoparticles) and advanced genetic tools (CRISPR/Cas9, GWAS), promise scalable solutions for breeding drought-resilient maize varieties. Despite this progress, challenges remain, including genotype-specific variability, scalability, and trade-offs between resilience and yield. This review provides a roadmap for integrating laboratory discoveries with field-level practices, bridging molecular and agronomic innovations to address climate variability and ensure sustainable maize production and global food security.