Location: Location not imported yet.Title: Haplotype variation of Glu-D1 locus and the origin of Glu-D1d allele conferring superior end-use qualities in common wheat Author
Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/8/2013
Publication Date: 9/30/2013
Citation: Dong, G., Yang, Y., Li, Y., Lou, H., An, X., Dong, L., Gu, Y.Q., Anderson, O.D., Liu, X., Qin, H., Zhang, K., Wang, D. 2013. Haplotype variation of Glu-D1 locus and the origin of Glu-D1d allele conferring superior end-use qualities in common wheat. PLoS One. 8(9):e74859. Interpretive Summary: Wheat is the most widely cultivated food crop in the world, providing valuable dietary energy and protein sources for over 60% of the world population. However, genetic improvement of wheat quality is still very challenging, largely due to the complexity of seed storage proteins in determining the baking quality of wheat flour. To understand the evolution and allelic variation of genes encoding the wheat seed storage proteins, particularly the high molecular weight glutenin (HMW-glutenin), we performed the detailed sequence analysis of the HMW-glutenin genes from wheat's diploid ancestral species, tetraploid wheat species, and hexaploid wheat cultivars of difference landraces. The research result provides a new insight into the evolution of the various haplotypes harboring different HMW-glutenin genes and offers a practical implication on use of these sequence variations in wheat quality improvement.
Technical Abstract: In common wheat (Triticum aestivum, AABBDD), the Glu-D1 locus possesses multiple alleles, with Glu-D1a (coding for 1Dx2 and 1Dy12 subunits) and Glu-D1d (encoding 1Dx5 and 1Dy10 subunits) being intensively used in the genetic improvement of end-use qualities. Here, we studied the molecular variations of Glu-D1 genomic region in order to understand the evolution of Glu-D1a and Glu-D1d. Using seven diagnostic DNA markers, 12 haplotypes for Glu-D1 locus were detected among common wheat, European spelt wheat (T. spelta, a more primitive hexaploid relative of common wheat), and Aegilops tauschii (the D genome donor of common wheat). By comparatively analyzing different Glu-D1 locus haplotypes and their associated 1Dx and 1Dy genes, it was found that Glu-D1a was originally derived from a highly similar allele in Ae. tauschii, whereas Glu-D1d was evolved in the ancestral common wheat around 10,000 years ago, and was subsequently transmitted to European T. spelta and free threshing common wheat. Furthermore, we found that the polymorphism of Glu-D1d was substantially higher in European T. spelta accessions than in contemporary common wheat varieties. Consistent with above findings, the haplotype harboring Glu-D1d was not identified in diverse Ae. tauschii accessions, but a group of relatively ancient Glu-D1 locus haplotypes was discovered, which may serve for the evolution of the various haplotypes associated with both Glu-D1a and Glu-D1d. The main steps in the evolution of Glu-D1a and Glu-D1d, and the practical implications of our work on further use of Glu-D1d in wheat quality improvement, are proposed and discussed.