Submitted to: International Gluten Workshop
Publication Type: Proceedings
Publication Acceptance Date: 10/6/2006
Publication Date: 5/1/2007
Citation: Blechl, A.E., Lin, J.W. 2007. Expression patterns in transgenic wheats with elevated levels of Dx5 and/or Dy10 glutenin subunits. International Gluten Workshop. Gluten Proteins 2006, pg. 107-111. tb
Interpretive Summary: Genetic transformation of wheat allows improvements to be made that are difficult or impossible by traditional breeding. However, a minority of wheat transformants exhibit unintended properties such as reductions in yield, suppression of the expression of genes that are closely related to the incoming genes, or new proteins that are the products of rearrangements within the incoming genes. This manuscript summarizes results from seven biolistic transformation experiments that resulted in 29 transgenic wheat plants with additional copies of the native wheat genes that make large glutenins Dx5 and Dy10. The majority of the lines derived from these plants had the expected seed protein composition and no reductions in yield or other changes in field performance. However, 3 had reductions in yield, 7 showed suppression of other large glutenins, and 7 had glutenin proteins that were larger or smaller than the original Dx5. The results underscore the need for generating multiple independent transformants for each gene of interest and the importance of extensive characterization of transgenic wheat lines.
Technical Abstract: In order to study the effects of independently increasing the levels of high-molecular-weight glutenin subunits (HMW-GS) Dx5 and Dy10, we added copies of their genes to wheat by genetic transformation. Among 29 homozygous lines produced, seven exhibited transgene-mediated co-suppression and seven showed the presence of extra proteins of unpredicted sizes in SDS-PAGE. In field trials, most of the lines were indistinguishable from their non-transformed parent in agronomic performance, but three exhibited reductions in yield, including one with transgene-mediated co-suppression and one with a novel seed protein.