Advances in CRISPR based genome editing for developing climate resilient and nutritionally enhanced maize

Abstract Maize ( Zea mays L. ) is a globally important crop that underpins food, feed, and industrial sectors. However, its production is increasingly constrained by climate-induced stresses such as drought, heat, and pests, as well as by inherent nutritional limitations, including low protein quality and micronutrient deficiencies. Conventional breeding and transgenic approaches have contributed to yield improvement, but they are time-consuming, labor-intensive, and limited in addressing complex polygenic traits. CRISPR-based genome editing has emerged as a revolutionary, precise, and efficient platform for accelerating maize improvement. Through versatile systems such as CRISPR/Cas9, Cas12a, and Cas13, researchers have successfully modified genes associated with drought tolerance, nutrient assimilation, and kernel quality. Advances including promoter engineering, base and prime editing, and haploid-inducer mediated editing (HI-Edit) enable rapid and transgene-free trait development directly in elite varieties. This review critically synthesizes recent progress in the application of CRISPR technologies for enhancing climate resilience and nutritional enrichment in maize. It highlights molecular strategies linking stress tolerance to improved nutrient utilization and identifies persistent challenges, including transformation efficiency, field-level validation, and diverse regulatory interpretations across regions. Overall, CRISPR-mediated editing represents a transformative tool to develop climate-smart, nutritionally enhanced maize varieties capable of sustaining yield, quality, and resilience in an era of global climate change.