Rapid identification and quantitation of high-molecular-weight glutenin subunits

Knowledge of glutenin-subunit composition is important for the prediction of the genetic potential of breeding lines for dough quality. In screening for quality using the Glu-1 scoring system, the high-molecular-weight glutenin subunits (HMW-GS) are especially valuable. This information is needed at the earliest stages of breeding to ensure that poor-quality lines are not propagated. Conventionally, glutenin polypeptides have been identified by SDS gel electrophoresis, but this method is slow, labour-intensive and only semi-quantitative. The recent Lab-on-a-Chip technology provides faster micro-fluidic analysis of these proteins at 1 min per analysis (3 min, given instrument conditioning time). To screen breeding lines for dough quality, the Lab-on-a-Chip approach offers quick quantification of specific glutenin subunits with computerized interpretation. To achieve these objectives, we have allocated subunit identities to the peaks in the Lab-on-a-Chip sample profiles, using multiple-deletion lines of wheat and varieties of known composition. The positions of HMW-GS can be used to identify the composition of unknown varieties and breeders' lines by computerized comparison against this established library of profiles from the Lab-on-a-Chip.