Molecular Characterization of CRISPR-Cas9-Edited Rice Across Generations and Associated Technical Challenges in Nucleotide Editing Tracing

CRISPR (clustered regularly interspaced short palindromic repeats) gene-edited (GEd) crops have demonstrated significant potential to enhance global food security in the face of escalating climate challenges and rapid population growth.Since 2019, for regulatory purposes, the United States (U.S.) and several other countries have recognized transgene-free, genome-edited lines as equivalent to conventionally bred varieties.Notably, the first genome-edited food product, Calyno soybean oil, was commercialized in the U.S. and marketed as a non-genetically modified organism (GMO) item.Recently, regulatory frameworks, such as the enactment of the Precision Breeding Law in the United Kingdom, the European Union's New Genomic Techniques (NGT) legislation, and the repeal of the SECURE Rule in the United States, have further established guidelines permitting the use of genome-edited lines in agriculture similar to with conventionally bred crops, provided that these lines are free of transgenic elements.In Korea, researchers and policymakers are actively engaging in discussions to establish a preliminary review committee for GEd crops to align regulatory practices with international trade standards.Thus, this study aimed to evaluate two gene-edited rice lines for generational stability in terms of molecular characteristics, focusing on edited nucleotide sequences, gene expression, target phenotypes, the presence of transgene elements, and potential off-target effects across multiple generations.Additionally, several technical challenges in nucleotide editing tracing emerged during the evaluation process that warrant further attention.The findings presented in this study are expected to offer valuable insights for shaping the regulatory framework in Korea for CRISPR-based gene-edited crops.