Genomes of 78 Arabidopsis Col-0 laboratory strains reveal decades of silent genetic and epigenetic drift

Researchers have sequenced the genomes and DNA methylomes of 78 Columbia-0 (Col-0) strains of the model plant Arabidopsis thaliana, sourced from laboratories and stock centres around the world, according to a preprint deposited on bioRxiv. Col-0 has served as the reference genotype for plant biology since the 1950s, when it was widely adopted and subsequently distributed through seed sharing among laboratories worldwide.

The study reconstructs the propagation history of these strains and finds that independent propagation over approximately seven decades has produced measurable genetic divergence — including single nucleotide variants and small structural differences — as well as epigenetic variation in DNA methylation patterns. The extent of divergence varies with the inferred propagation history of each lineage.

For plant geneticists and researchers working with Arabidopsis, the findings carry practical implications for experimental reproducibility. Studies comparing results across different Col-0 strains may need to account for the possibility that the strains are not genetically or epigenetically identical, even when nominally described as the same reference accession. The preprint has not yet been peer-reviewed.