CRISPR technology for abiotic stress resistant crop breeding

CRISPR has brought a revolutionary impetus to the field of life sciences. The abundance of CRISPR arrays found in nature and the programmability of Cas nucleases have catalyzed the development of gene editing tools based on CRISPR. CRISPR technology has seen applications in agriculture and has greatly accelerated the process of crop breeding. We review a number of CRISPR-based genome editing approaches having been used in plants. Then we present the contributions these approaches have made to the breeding of crops resistant to abiotic stresses that prominently decline crop production. The principles, characteristics and scope of application of different gene modification methods are summarized and compared. Regarding abiotic stress-related genes, we respectively introduced what strategies can be used for the two types of genes, abiotic stress-sensitive and -tolerance gene, to obtain resistant crops. Besides, we summarized the application of precision genome editing in abiotic stress, including CRISPR-based NHEJ, HDR and base-editing methods. We also point out the technical bottlenecks faced by CRISPR-based breeding of abiotic stress-resistant crops and discuss the potential applications of CRISPR in crop improvement.