Breeding by Design for Functional Rice with Genome Editing Technologies

The conventional approaches to crop breeding, which rely predominantly on time-consuming and labor-intensive methods such as traditional hybridization and mutation breeding, face challenges in efficiently introducing targeted traits and generating diverse plant populations. Conversely, the emergence of genome editing technologies has ushered in a paradigm shift, enabling the precise and expedited manipulation of plant genomes to intentionally introduce desired characteristics. One of the most widespread editing tools is the CRISPR/Cas system, which has been used by researchers to study important biology-related problems. However, the precise and effective workflow of genome editing has not been well-defined in crop breeding. In this study, we demonstrated the entire process of breeding rice varieties enriched with high levels of resistant starch (RS), a functional trait that plays a crucial role in preventing diseases such as diabetes and obesity. The workflow encompassed several key steps, such as the selection of functional SBEIIb gene, designing the single-guide RNA (sgRNA), selecting an appropriate genome editing vector, determining the vector delivery method, conducting plant tissue culture, genotyping mutation and phenotypic analysis. Additionally, the time frame necessary for each stage of the process has been clearly demonstrated. This protocol not only streamlines the breeding process but also enhances the accuracy and efficiency of trait introduction, thereby accelerating the development of functional rice varieties.