Genetic, molecular and physiological crosstalk during drought tolerance in maize (Zea mays): pathways to resilient agriculture.

Abstract

Main conclusion: This review comprehensively elucidates maize drought tolerance mechanisms, vital for global food security. It highlights genetic networks, key genes, CRISPR-Cas applications, and physiological responses, guiding resilient variety development. Maize, a globally significant crop, confronts the pervasive challenge of drought stress, impacting its growth and yield significantly. Drought, an important abiotic stress, triggers a spectrum of alterations encompassing maize's morphological, biochemical, and physiological dimensions. Unraveling and understanding these mechanisms assumes paramount importance for ensuring global food security. Approaches like developing drought-tolerant varieties and harnessing genomic and molecular applications emerge as effective measures to mitigate the negative effects of drought. The multifaceted nature of drought tolerance in maize has been unfolded through complex genetic networks. Additionally, quantitative trait loci mapping and genome-wide association studies pinpoint key genes associated with drought tolerance, influencing morphophysiological traits and yield. Furthermore, transcription factors like ZmHsf28, ZmNAC20, and ZmNF-YA1 play pivotal roles in drought response through hormone signaling, stomatal regulation, and gene expression. Genes, such as ZmSAG39, ZmRAFS, and ZmBSK1, have been reported to be pivotal in enhancing drought tolerance through diverse mechanisms. Integration of CRISPR-Cas9 technology, targeting genes like gl2 and ZmHDT103, emerges as crucial for precise genetic enhancement, highlighting its role in safeguarding global food security amid pervasive drought challenges. Thus, decoding the genetic and molecular underpinnings of drought tolerance in maize sheds light on its resilience and paves the way for cultivating robust and climate-smart varieties, thus safeguarding global food security amid climate challenges. This comprehensive review covers quantitative trait loci mapping, genome-wide association studies, key genes and functions, CRISPR-Cas applications, transcription factors, physiological responses, signaling pathways, offering a nuanced understanding of intricate mechanisms involved in maize drought tolerance.