Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 12, 2010
Publication Date: July 3, 2010
Citation: Xu, S.S., Khan, K., Klindworth, D.L., Nygard, G. 2010. Evaluation and characterization of high-molecular weight 1D glutenin subunits from Aegilops tauschii in synthetic hexaploid wheats. Journal of Cereal Science. 52:333-336. Interpretive Summary: Seed storage proteins are considered the most important components for end-use quality in wheat. Among the different types of proteins in wheat flours, the high-molecular weight (HMW) glutenins are among the most important determinants of baking quality in bread wheat. These proteins are controlled by the gene sets, named Glu-A1, Glu-B1, and Glu-D1, located on the long arms of the Group 1 chromosomes. The HMW glutenins from the Glu-D1 gene on chromosome 1D are particularly important in bread-making quality. Thus, identification of new variants or forms of Glu-D1 gene in wheat and related species is important for improving wheat quality. In this study, we analyzed HMW glutenin subunits controlled by Glu-D1 present in 44 synthetic hexaploid wheat (SHW) lines using protein electrophoresis. We identified 17 Glu-D1 variants in the 44 SHW lines. Eight of the variants each encode at least one new HMW glutenin subunit and they are newly designated as Glu-D1bs through D1bz. Quality testing of the SHW lines will determine if any of the Glu-D1 variants identified in this study are useful in improving wheat baking quality.
Technical Abstract: The high-molecular weight (HMW) glutenin subunits of bread wheat (Triticum aestivum L.) are major determinants of end-use quality. The objective of this study was to determine the 1Dx and 1Dy HMW subunits present in 44 synthetic hexaploid wheats (SHW) derived by crossing Langdon durum (T. turgidum L. ssp. durum) to 43 Aegilops tauschii Cosson accessions. Proteins were extracted and samples were run on 8% and 12% SDS-PAGE gels. Following multiple runs to arrange subunits into similar groups, samples were run on 12% urea SDS-PAGE gels. Initial results with SDS-PAGE gels indicated that there were six 1Dx subunits and six 1Dy subunits present in the SHW lines, and none of these were new alleles. However, results of the urea SDS-PAGE indicated that some of the subunit groups could be further differentiated into additional subunits. Following urea SDS-PAGE, there were 11 1Dx and eight 1Dy subunits, and these included the new subunits 1Dx2t-1, 1Dx2t-2, 1Dx2t-3, 1Dx1.5t-1, 1Dx2.1t-1, 1Dy10t-1 and 1Dy12t-1. Subunits 1Dx2t and 1Dy10t-1 were the most frequently observed subunits, occurring in 15 and 24 SHW lines, respectively. Seventeen different alleles were observed in the 44 SHW lines. Eight of these alleles included at least one novel subunit and hence were newly designated as Glu-D1bs through D1bz. Our results indicated that urea SDS-PAGE can be very useful in identifying new HMW glutenin subunits. Quality testing of the SHW lines will determine if any of the alleles are useful in improving wheat baking quality.