Plant genomic variation and its implications for proposed EU NGT legislation

Alan H. Schulman, Frank Hartung, Marinus J.M. Smulders, Jens F. Sundström, Ralf Wilhelm, Odd Arne Rognli, Karin Metzlaff

The European Commission proposal for New Genomic Techniques (NGTs) of July 2023 specifies that NGT1 plants, which are considered equivalent to conventional plants, may differ from the recipient or parental plant by no more than 20 insertions, which cannot be longer than 20 bp; deletions can be of any size and number. Here, we examine the proposed 20/20 NGT1 limit against the background of the theoretical considerations and older data used to frame it and in light of recent data from highly contiguous long-read assemblies for reference genomes and pangenomes. We find that current genomic data indicate that natural variation in germplasm used by breeders is much greater than earlier understood and that both conventional breeding and mutagenesis can introduce genomic changes that are both more extensive in size and more frequent than the NGT Category 1 “20 insertions of maximum 20 bp” limit would allow. Furthermore, natural variation also scales with genome size and complexity, a factor not considered in the EC proposal. We conclude that the proposed cutoffs under which an NGT plant is considered equivalent to conventional plants do not align with what is observed in nature, conventional breeding, and mutagenesis. Updating the 20/20 rule to broader limits would facilitate breeding for climate resilience, farming sustainability, and nutritional security, while ensuring that NGT1 plants are equivalent to conventional ones.