CRISPR/Cas9-mediated genome editing of OsCS511 enhances cold tolerance in Oryza sativa L.

The frequency of climate change is increasing globally, which makes predictions challenging. Cold spells during the rice seedling stage can significantly reduce yield, prompting a constant need for cold-tolerant cultivars, which is a major breeding goal. However, the traditional crossbreeding of rice cultivars requires substantial time and effort. Recently, the application of CRISPR/Cas9 to reduce defects in elite cultivars has become a more cost-effective and time-efficient method for breeding cultivars than cross-breeding methods and can alleviate food insecurity. In the present study, CRISPR/Cas9-mediated genome editing was performed for OsCS511 a gene involved in cold susceptibility, identified using quantitative trait loci (QTL) mapping in Ilmi (Oryza sativa L. spp. Japonica cv. Ilmi). In Ilmi, CRISPR/Cas9 tool-edited OsCS511 homozygous lines were used in T₀ and advanced generations in the field. CRISPR/Cas9 induced variations in the DNA sequence and plants with insertions or deletions compared to OsCS511 of Ilmi were selected as genome-edited lines. Agricultural traits, reactive oxygen species scavenging capacity, and stress-tolerance-related gene expression levels were evaluated under normal and cold stress conditions. Under normal conditions, all traits evaluated in the Ilmi and OsCS511 genome-edited lines exhibited similar results; however, when subjected to cold stress, the cold tolerance of OsCS511 genome-edited lines improved or reached the same level as that of Ilmi. OsCS511 genome-edited lines recovered and survived. From a breeding perspective, we suggest that CRISPR/Cas9 technology can precisely reduce defects in existing superior rice cultivars with high efficiency and speed.