A chromosome-based draft sequence of the hexaploid bread wheat ( <i>Triticum aestivum</i> ) genome

TLDR

The study aims to use the wheat genome draft to accelerate gene isolation, marker development, and breeding to meet global food demand. The draft sequence of the 17‑Gb hexaploid wheat genome revealed 124,201 genes, high conservation and structural similarity across subgenomes, limited gene loss, dynamic gene gain/loss/duplication, and transcriptional autonomy without global dominance.

Abstract

An ordered draft sequence of the 17-gigabase hexaploid bread wheat (Triticum aestivum) genome has been produced by sequencing isolated chromosome arms. We have annotated 124,201 gene loci distributed nearly evenly across the homeologous chromosomes and subgenomes. Comparative gene analysis of wheat subgenomes and extant diploid and tetraploid wheat relatives showed that high sequence similarity and structural conservation are retained, with limited gene loss, after polyploidization. However, across the genomes there was evidence of dynamic gene gain, loss, and duplication since the divergence of the wheat lineages. A high degree of transcriptional autonomy and no global dominance was found for the subgenomes. These insights into the genome biology of a polyploid crop provide a springboard for faster gene isolation, rapid genetic marker development, and precise breeding to meet the needs of increasing food demand worldwide.