As recent advances in gene editing technologies have enabled rapid and accurate modification of target genes, new varieties are being developed through the application of gene editing technologies in various crop species. In particular, the CRISPR/Cas9 system has become a tool of choice for gene editing because it is much more economical and efficient than previous tools such as ZFN and TALEN, and is being actively used to improve various breeding traits, including biotic and abiotic stress tolerance to overcome the limitations of conventional plant breeding technologies. In this review, we retrieved 210 papers describing the utilization of CRISPR/Cas9 in rice published between 2013 and 2021 and classified them according to the field of study and traits of interest. Further case studies were conducted on 21 and 12 research papers that reported the enhancement of biotic and abiotic stress tolerance, respectively. This demonstrated that CRISPR/Cas9-based gene editing can be highly effective in improving resistance to bacterial (bacterial leaf blight and bacterial leaf streak), fungal (blast, sheath blight), and viral (rice tungro spherical virus, rice black streak virus) diseases as well as various abiotic stresses, including drought, salinity, cold, and heat, in many cases, without diminishing important agronomic traits. As recent technological advances have begun to overcome the major limitations of CRISPR/Cas9 gene editing, such as low HDR efficiency and off-target effects, it is expected that more research on gene function and cultivar development will adopt CRISPR/Cas9 as a major gene editing tool in the future. To effectively apply such innovative technologies in crop improvement, much effort is required to establish more reasonable and detailed policies for regulating crops developed through new breeding technologies.

Recently, several attempts have been undertaken to develop breeding technologies by combining new biotechnologies. Gene-editing technology is currently one of the most interesting areas. The plant breeding methods using this technique have the advantage of greatly improved accuracy and efficiency of the plant genetic correction compared with conventional breeding methods, which has raised expectations for the useful application of this technology as a cutting-edge breeding technology. Although not all countries around the world currently have established appropriate regulation policies on crops developed with gene-editing technology, the number of cases in which GMO regulations are not applied on a case-by-case basis according to the scientific background is growing. However, Korea has not yet established policies on which criteria should be applied to crops generated from the application of gene-editing technology. As the number of cases of crop development and commercialization using gene-editing technology is expected to increase in the near future, it will be necessary to prepare reasonable policies to support developers and seed industries in Korea to ensure harmonization with international regulatory policy trends.