Epigenomic atlas in wheat reveals regulatory elements specifying subgenome divergence

Abstract

Whole-genome duplication or polyploidy is widespread throughout eukaryotes but is most prevalent in flowering plant lineages. The evolutionary processes following polyploidization, such as genome downsizing, biased fractionation, modulation of gene expression, and epigenomic reprogramming, can profoundly affect genome complexity and generate evolutionarily beneficial genetic diversity. Compared to its diploid and tetraploid progenitors, the allohexaploid common wheat (Triticum aestivum, AABBDD) displays remarkable genome plasticity and broader adaptability, attributed in part to the creation of new genetic diversity following allopolyploidy. How gene copies in the three different subgenomes of wheat are regulated and coordinate molecular responses through combinatorial and dosage-dependent manner is a matter of ongoing research.