Genome Editing Enhanced Abiotic Stress ToleranceIn Cereal Crops

Cereals are crucial sources of food for human and animal populations worldwide. Their grain and fodder primarily serve as sources of energy and nutrition. Cereal production is hampered because of the prevalent abiotic stress worldwide. Abiotic stresses such as drought, salinity, extreme temperatures, and heavy metal toxicity significantly reduce global cereal crop production. Previously, traditional breeding and transgenic technology have been promising and potent approaches used to mitigate unfavourable abiotic stresses, enhancing crop production to some extent. The recent advent of more potent genome-editing technologies, particularly Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), has revolutionized the pace of crop improvement programs. Genome-editing technology using engineered nucleases offers significant opportunities for crop improvement. Genome editing tools include Meganucleases, Zinc Finger Nucleases (ZFN), Transcription activator-like effector nucleases (TALENs), and CRISPR/CRISPR-associated protein (Cas). Among all genome-editing tools, CRISPR/Cas9 has been widely used to improve crop cultivars due to its specificity, simplicity, robustness, and flexibility. Recent progress in genome-editing technology have improved various plant traits in cereals. Among these traits, cereal genotypes have shown substantial advances in the last decade, particularly in enhanced tolerance to abiotic stress, enabled by genome-editing tools. This review summarizes the recently developed cereal cultivars for abiotic stress tolerance that employ different genome-editing technologies, including the most recent additions, prime editing and base editing. These improved cereal cultivars perform better and maintain higher yields under adverse abiotic stresses.