Molecular characterization of three transgenic high molecular weight glutenin subunit events in winter wheat

• The overexpression of HMW-GS amplified the glutenin molecular weight.
• The transgenic Dy10-E event displayed the highest molecular weight distribution.
• Hardness showed a moderate positive correlation with glutenin molecular weight.
• Technological parameters were strongly influenced by polymer weight distribution.

Lab-on-a-chip separation and asymmetrical flow field-flow fractionation and multi-angle laser light scattering were used to characterize the polymeric protein fraction of three transgenic high molecular weight glutenin subunit (HMW-GS) events in advanced breeding lines of hard winter wheat (Triticum aestivum L.). In the transgenic event B52a6, HMW-GS 1Dy10 was produced at respective rates of 6.7 and 4.6 times higher than those of non-transgenic B52a6 siblings and control cultivars. In transgenic event Dy10-E, the observed amount of 1Dy10 was approximately 5.7 and 5.8 fold greater than those of non-transgenic Dy10-E derivatives and controls. Event Dx5 + Dy10-H over-produced HMW-GS 1Dx5 at rates of approximately five to six fold higher than l non-transgenic siblings and controls, respectively. All three transgenic events exhibited significantly greater average molecular mass of glutenin than those of both controls and the respective non-transgenic siblings. The transgenic Dy10-E event displayed the largest polymer molecular weight distribution. The percentage of protein found in polymeric form, however, did not increase in any of the three events. Technological properties, including mixograph time to peak, mixograph tolerance, bake mix time and loaf volume were strongly dependent upon the average Mw and glutenin quantity.