Effect of high-molecular-weight glutenin subunits silencing on dough aggregation characteristics

The qualities of wheat dough are influenced by the high-molecular-weight glutenin subunits (HMW-GS), a critical component of wheat gluten protein. However, it is still unknown how HMW-GS silencing affects the aggregation characteristics of dough. Two groups of near-isogenic wheat were used to study the effects of HMW-GS silencing on dough aggregation characteristics, dough texture characteristics, and dough microstructure. It was observed that the content of gliadin in LH-11 strain significantly increased compared to the wild-type (WT). Additionally, the amount of glutenin macropolymer and the glutenin/gliadin both decreased. The aggregation characteristics and rheological characteristics of the dough in LH-11 strain were significantly reduced, and the content of β-sheet in the dough was significantly reduced. The HMW-GS silencing resulted in a reduction in the aggregation of the gluten network in the dough, which related to the alteration of the secondary and microstructure of the gluten.

durum) improves milling and pasting quality

BACKGROUND

Durum wheat is considered not suitable for making many food products that bread wheat can. This limitation is largely due to: (i) lack of grain-hardness controlling genes (Puroindoline a and b) and consequently extremely-hard kernel; (ii) lack of high- and low-molecular-weight glutenin subunit loci (Glu-D1 and Glu-D3) that contribute to gluten strength. To improve food processing quality of durum wheat, we stacked transgenic Pina and HMW-glutenin subunit 1Ax1 in durum wheat and developed lines with medium-hard kernel texture.

RESULTS

Here, we demonstrated that co-expression of Pina + 1Ax1 in durum wheat did not affect the milling performance that was enhanced by Pina expression. While stacking of Pina + 1Ax1 led to increased flour yield, finer flour particles and decreased starch damage compared to the control lines. Interestingly, Pina and 1Ax1 co-expression showed synergistic effects on the pasting attribute peak viscosity. Moreover, Pina and 1Ax1 co-expression suggests that PINA impacts gluten aggregation via interaction with gluten protein matrix.

CONCLUSIONS

The results herein may fill the gap of grain hardness between extremely-hard durum wheat and the soft kernel durum wheat, the latter of which has been developed recently. Our results may also serve as a proof of concept that stacking Puroindolines and other genes contributing to wheat end-use quality from the A and/or D genomes could improve the above-mentioned bottleneck traits of durum wheat and help to expand its culinary uses.