Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2002
Publication Date: 9/20/2002
Citation: SANGTON, V., MORAN, D.L., CHIKWAMBA, R., WANG, K., WOODMAN-CLIKEMAN, W., LONG, M.J., LEE, M., SCOTT, M.P. EXPRESSION AND INHERITANCE OF THE WHEAT GLU-1DX5 GENE IN TRANSGENIC MAIZE. THEORETICAL AND APPLIED GENETICS. 2002. v. 105. p. 937-945. Interpretive Summary: Wheat is used for bread making because it produces elastic dough. The seed proteins known as glutenins are important determinants of dough elasticity. Other cereals, including maize do not produce glutenins. We have developed transgenic maize plants that produce a wheat glutenin in their kernels. Ultimately, this maize could have improved flour properties that would make eit good for production of tortillas or other corn products. It could also be useful for the study of gluten intolerance. To be useful for these purposes, it is important to understand how the gene functions in corn. This manuscript describes the tissue specificity of the gene in corn, which is similar to the tissue specificity in wheat. We also examine the inheritance of the gene and show that unlike wheat, this gene is not transmitted through the pollen. This unusual inheritance pattern is important because it may reveal new information about pollen development or rfertilization. This technology may have commercial application in seed production or transgene deployment, where it could benefit developers and producers of transgenic corn.
Technical Abstract: We have produced transgenic maize plants containing a wheat Glu1-Dx5 gene encoding the high molecular weight glutenin subunit 1Dx5. Analysis by SDS-PAGE showed that a protein similar in size to the wheat 1Dx5 subunit accumulates in the endosperm of transgenic maize from four independent transformation events. This protein reacts with a monoclonal antibody specific to the wheat 1Dx5 subunit and was not detected in non-transgenic controls or in pollen, anthers, leaves, or embryos of plants grown from seeds expressing this protein in endosperm. Genomic Southern blot analysis is consistent with results from SDS-PAGE and indicates that the transgene integration sites are complex and are different in the four events studied. Using the presence of this protein as a phenotypic marker, we studied the inheritance of this gene through three sexual generations. Reciprocal crosses with non-transgenic plants and self-pollinations were performed and dthe resulting kernels were analyzed for the presence of the 1Dx5 subunit. These data, together with PCR analysis for the transgene, suggest the transgene is inefficiently transmitted through pollen in all four events.