Genome duplication in plants
Polyploidisation serves as a major speciation mechanism in land plants, but little is known about the performance, dynamics and evolutionary potential of wild polyploid lineages. Delineating the underlying mechanisms is central for biodiversity conservation and decipherment of the evolution of economically important genes in different genetic or ecological backgrounds. Arabidopsis thaliana constitutes a leading model for genetic and evolutionary research. Scientists of the EU-funded WILD ARABIDOPSIS (Pathways, ecological and genomic consequences of genome duplication in Arabidopsis arenosa, an overlooked diploid-polyploid member of the model genus Arabidopsis) project focused on A. arenosa, an overlooked yet extremely promising species that represents the closest wild di/polyploid relative to A. thaliana. The European species A. arenosa comprises populations of variable number of whole chromosome sets (diploid and autotetraploid) and represents an emerging model for evolution through genome duplication. The primary objectives of WILD ARABIDOPSIS were to analyse the genetic structure of A. arenosa, trace the interactions among its two ploidy levels, and assess the diversity of biologically important traits over various geographical areas and environments. Towards this goal, researchers employed high-throughput genotyping techniques and eco-spatial analysis to decipher how niche shifts the structured genetic diversity of A. arenosa. Results showed that the Eastern-Central European mountains played an important role in the genetic makeup of current populations. In particular, two of the Central European lineages hybridised and spread to a distinct postglacial environment in Northern Europe. To evaluate the evolutionary consequences of genome duplication, scientists compared 300 genomic sequences of A. arenosa of both ploidy levels. Results indicated a frequent gene flow within and across ploidy levels, suggesting a potential effect on evolution and adaptation. Overall, the project provided important background information about the evolutionary history, structure of genetic diversity and phenotypic variation of A. arenosa. This knowledge is expected to fuel follow-up studies focused on agricultural and/or genetic applications.
Keywords
Genome duplication, evolution, polyploid, WILD ARABIDOPSIS, Arabidopsis arenosa