High Molecular Weight Glutenin Subunits 1Bx7 and 1By9 Encoded by Glu-B1 Locus Affect Wheat Dough Properties and Sponge Cake Quality.

High molecular weight glutenin subunits (HMW-GSs) are important components of wheat (Triticum aestivum L.) gluten proteins that affect the processing quality of wheat dough. However, the contributions of individual HMW-GS to sponge cake quality still remain unclear. To investigate the effects of 1Bx7 and 1By9 at Glu-B1 on wheat gluten properties and sponge cake quality, we screened an ethylmethanesulfonate (EMS)-mutagenized wheat population and obtained two independent mutants that lack 1Bx7 and another two mutants that lack 1By9. The absence of 1Bx7 or 1By9 significantly affects the accumulation levels of gluten proteins and the formation of a gluten network. Quality testing indicated that the lack of 1Bx7 or 1By9 leads to weaker dough strength and inferior sponge cake performance. These results demonstrate that 1Bx7 and 1By9 make important contributions to gluten functionality and sponge cake quality.