Engineering abiotic stress resilience in crops using CRISPR/Cas: from tools to trait improvement

Abiotic stress factors, including drought, temperature, salinity, pesticides, and toxic metals, significantly limit crop productivity. Traditional breeding methods and genome-editing technologies can mitigate the harmful effects of these environmental stresses. The CRISPR/Cas-mediated genome editing is a unique framework that can manipulate crop stress-responsive genes and related molecular networks more affordably, easily, and quickly than before. In this review, we explain how CRISPR/Cas-based systems rapidly developed from Cas9 and Cas12 to various Cas orthologues. We discuss different CRISPR/Cas technologies, such as base editing and prime editing, which are widely used for precise editing of the desired genome, epigenome, and transcriptome, as well as methods for delivering genome editors into the desired plants, such as Agrobacterium-mediated and biolistic transformation. Also, we summarize recent findings on a better understanding of the mechanistic basis of abiotic stress responses in plants and on the important applications of CRISPR/Cas in improving crop tolerance to drought, salinity, cold, heat, and heavy metals. This review concludes the future perspectives of plant genome engineering to improve crop resilience to abiotic stresses.