Researchers sequence sugar beet genome
The current work, nevertheless, went one step further and generated genome assemblies from four additional sugar beet lines. This allowed the researchers to obtain a much better picture of intraspecific variation in sugar beet than would have been possible otherwise. In summary, 7 million variants were discovered throughout the genome. However, variation was not uniformly distributed: The authors found regions of high, but also of very low variation, "reflecting both the small population size from which the crop was established, as well as the human selection, which has shaped the plants’ genomes. Additionally, gene numbers varied between different sugar beet cultivars, which contained up to 271 genes not shared with any of the other lines", as Juliane Dohm and André Minoche, two scientists involved in the study commented.
The researchers also performed an evolutionary analysis of each sugar beet gene in order to put them into context with already known genes of other plants. This analysis allowed them to identify gene families that are expanded in sugar beet compared to other plants, but also families that are absent. Notably such gene families were most commonly associated with stress response or with disease resistance, added Toni Gabaldon, group leader in the CRG Bioinformatics and Genomics programme and ICREA research professor.
Finally, the work also provides a first genome sequence of spinach, which is a close relative of sugar beet.
Thanks to the sugar beet genome sequence made by the researchers and the associated resources generated, future studies on the molecular dissection of natural and artificial selection, gene regulation and gene-environment interaction, as well as biotechnological approaches to customize the crop to different uses in the production of sugar and other natural products, are expected to be held.
“Sugar beet will be an important cornerstone of future genomic studies involving plants, due to its taxonomic position”, the authors claim.