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Production of the wheat high molecular weight glutenin subunit 1Dx5 in the grain of transgenic corn.
M. P. SCOTT (1), V. Sangtong (2), and D. L. Moran (1). (1) USDA-ARS, Ames, IA, 50011; (2) Iowa
State University, Department of Agronomy, Ames, IA 50011.
The high molecular weight glutenins are seed storage proteins that have
a large impact on the viscoelastic properties of dough made from wheat flour. Dough made from corn flour
has very poor elasticity and extensibility, so flat breads made from corn flour do not withstand folding as
well as similar breads made from wheat flour. In an effort to remedy this situation, we have developed
transgenic corn plants that produce the wheat high molecular weight glutenin subunit 1Dx5 in the grain. To
determine the best method for production of this protein in corn grain, we compared the effectiveness of the
wheat 1Dx5 promoter with the corn gamma zein promoter. 1Dx5 accumulated to high levels in the grain in
both cases, but in plants containing the wheat 1Dx5 promoter, the transgene was not transmitted efficiently
through the pollen. Pollen transmission was limited in four separate transformation events, suggesting that
the transgene itself, rather than the insertion event, is responsible for this effect. The gamma zein driven
1Dx5 gene is transmitted normally through the pollen, which will enable us to produce homozygous plants
and proceed with a breeding program. We plan to test the functional properties of 1Dx5 containing corn
flour. In addition, 1Dx5 containing corn may be valuable for investigations of wheat gluten allergies.
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