Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/14/2003
Publication Date: 7/8/2003
Citation: MASCI, S., D'OVIDIO, R., SCOSSA, F., PATACCHINI, C., LAFIANDRA, D., ANDERSON, O.D., BLECHL, A.E. PRODUCTION AND CHARACTERIZATION OF A TRANSGENIC BREAD WHEAT LINE OVER-EXPRESSING A LOW-MOLECULAR WEIGHT GLUTENIN SUBUNIT GENE. MOLECULAR BREEDING. 2003. v. 12. p. 209-222. Interpretive Summary: The utilization of wheat rests primarily on the fact that wheat flour and water mixtures form a visco-elastic dough from which a myriad of food products are produced. This visco-elastic property is, in turn, conferred mainly by the wheat proteins in the flour. One class of these proteins, the low-molecular-weight (LMW) glutenins, have been known to be involved in dough properties, but the large and varied number of these proteins, and related proteins in the flour, has made understanding their exact role difficult to determine. By using biotechnology procedures, the amount of one of these proteins has been dramatically increased in a wheat line. This increased synthesis has allowed new studies in the effects of these proteins on wheat flour, and is suggesting additional experiments to carry out. One finding of these initital experiments is that the LMW glutenins form polymers that can have negative effects on wheat dough quality.
Technical Abstract: The end-use properties, and thus the value, of wheat flours are determined to a large extent by the proteins that make up the polymeric network called gluten. Low molecular weight glutenin subunits (LMW-GS) are important components of gluten structure. Their relative amounts and/or the presence of specific components can influence dough visco-elasticity, a property that is correlated with the end-use properties of wheat flour. For these reasons, we are investigating the possibility of manipulating gluten dough strength and elasticity. We are pursuing this goal by transforming the bread wheat cultivar Bobwhite with a LMW-GS gene driven by its own promoter. We have determined that the transgene-encoded LMW-GS accumulates to very high levels in seeds of this line, and that it is incorporated into the glutenin polymer, nearly doubling its overall amount. However, SDS sedimentation test values were lower for whole wheat flour from the transgenic material compared to a control flour that had a lower protein content. These results indicate that the widely accepted correlation between the amount of the glutenin polymers and flour technological properties might not be valid, depending on the components of the polymer.