Engineering rice for enhanced abiotic stress tolerance using genome editing

Rice productivity is increasingly constrained by drought, salinity, heat, cold, submergence, heavy metal toxicity, and herbicide-related stresses. Although conventional breeding has improved stress tolerance, progress remains limited by the complex, polygenic, and environment-dependent nature of abiotic stress responses. Genome-editing technologies, including CRISPR/Cas systems, TALENs, ZFNs, base editors, prime editors, and CRISPR-Combo, provide precise approaches for modifying stress-responsive genes and regulatory pathways. This review summarizes recent genome-editing advances in rice for major abiotic stresses, highlighting validated targets involved in ROS homeostasis, ABA signaling, calcium/MAPK cascades, transcriptional regulation, ion transport, epigenetic control, and cross-stress signaling networks. It also discusses key limitations, including off-target effects, delivery constraints, low knock-in efficiency, genotype-dependent transformation, and regulatory challenges. Overall, genome editing offers a powerful strategy for developing climate-resilient rice cultivars, particularly when integrated with multiplex editing, precision allele engineering, and modern breeding approaches.