Expression and inheritance of the wheat Glu-1DX5 gene in transgenic maize

Abstract.

We have produced transgenic maize plants containing a wheat Glu-1Dx5 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 nontransgenic 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 nontransgenic plants and self-pollinations were performed, and the resulting kernels were analyzed for the presence of the 1Dx5 subunit. These data, together with PCR analysis for the transgene, suggest that the transgene is inefficiently transmitted through pollen in all four events.