Influence of high-molecular-weight glutenin subunit composition at Glu-B1 locus on secondary and micro structures of gluten in wheat (Triticum aestivum L.)

• HMW glutenin subunit composition at Glu-B1 affected secondary and micro structures of gluten.
• The content of β-sheets in gluten positively correlated to the stability of wheat dough.
• Bx14 + By15 and Bx17 + By18 gave distinguishing patterns of micro structure of gluten.

Glutenin is one of the critical gluten proteins that affect the processing quality of wheat dough. High-molecular-weight glutenin subunits (HMW-GS) affect rheological behavior of wheat dough. This research demonstrated the effects of four variations of HMW-GS composition at the Glu-B1 locus on secondary and micro structures of gluten and rheological properties of wheat dough, using the bread wheat Xinong 1330 and its three near-isogenic lines (NILs). Results indicated that the Amide I bands of the four wheat lines shifted slightly, but the secondary structure, such as content of α-helices, β-sheets, disulfide bands, tryptophan bands and tyrosine bands, differed significantly among the four NILs. The micro structure of gluten in NIL 2 (Bx14 + By15) and NIL 3 (Bx17 + By18) showed more cross linkage, with two contrasting patterns. Correlation analysis demonstrated that the content of β-sheets and disulfide bonds has a significant relationship with dough stability, which suggests that the secondary structures could be used as predictors of wheat quality.