Genome Triplication Leads to Transcriptional Divergence of Genes During Vernalization in the Genus .

The genus includes oil crops, vegetables, condiments, fodder crops, and ornamental plants. species underwent a whole genome triplication event after speciation between ancestral species of and closely related genera including . Diploid species such as and have three copies of genes orthologous to each gene, although deletion in one or two of the three homologs has occurred in some genes. The floral transition is one of the crucial events in a plant's life history, and time of flowering is an important agricultural trait. There is a variation in flowering time within species of the genus , and this variation is largely dependent on a difference in vernalization requirements. In , like in , the key gene of vernalization is (). In species, the vernalization response including the repression of expression by cold treatment and the enrichment of the repressive histone modification tri-methylated histone H3 lysine 27 (H3K27me3) at the locus is similar to . and each have four paralogs of , and the allotetraploid species, , has nine paralogs. The increased number of paralogs makes the role of in vernalization more complicated; in a single plant, paralogs vary in the expression level of before and after vernalization. There is also variation in expression levels between accessions. In this review, we focus on the regulatory circuits of the vernalization response of expression in the genus .