Implications of the EFSA Scientific Opinion on Site Directed Nucleases 1 and 2 for Risk Assessment of Genome-Edited Plants in the EU

Genome editing is a set of techniques for introducing targeted changes in genomes. It may be achieved by enzymes collectively called site-directed nucleases (SDN). Site-specificity of SDNs is provided either by the DNA binding domain of the protein molecule itself or by RNA molecule(s) that direct SDN to a specific site in the genome. In contrast to transgenesis resulting in the insertion of exogenous DNA, genome editing only affects specific endogenous sequences. Therefore, multiple jurisdictions around the world have exempted certain types of genome-edited organisms from national biosafety regulations completely, or on a case-by-case basis. In the EU, however, the ruling of the Court of Justice on the scope of mutagenesis exemption case C-528/16 indicated that the genome-edited organisms are subject to the GMO Directive, but the practical implications for stakeholders wishing to develop and authorize genome-edited products in the EU remain unclear. European Food Safety Authority in response to a request by European Commission has produced a scientific opinion on plants developed by SDN-1, SDN-2, and oligonucleotide-directed mutagenesis (ODM) genome editing techniques. In this review, I will (1) provide a conceptual background on GMO risk assessment in the EU; (2) will introduce the main conclusions of the EFSA opinion, and (3) will outline the potential impact on the risk assessment of genome-edited plants.