CRISPR Cas9 Applications for Sustainable Crop Improvement: Progress and Challenges

Employing the technology as molecular scissors offers sustainable solutions for agriculture by enhancing crop productivity. The paper describes the essential principles of CRISPR-Cas9, the functions of the Cas9 nuclease guided by RNA, the repair pathways NHEJ and HDR, and plant-optimised delivery systems, including Agrobacterium and RNPs. It showcases important applications, including GS3/GW2 edits for rice yield in cereals; improvements in biotic/abiotic resistance and shelf life in legumes and horticultural crops; case studies; and recent 2024-2025 efforts that resulted in 15-30% improvements in traits. Lucerne biotechnology has achieved transgene-free commercial varieties with recommended approval in many regions, but off-target effects, polyploid editing, regulatory disparities, and scalability issues persist. Greater emphasis should be placed on primary editing, multiplexing, phenomics, and other technologies for climate-smart breeding. The synthesis demonstrates that CRISPR-Cas9 can transform global food security by advancing interdisciplinary solutions to overcome barriers.