Engineering changes in wheat flour by genetic transformation

Abstract

Summary The strength and elasticity of doughs made from wheat ( Triticum aestivum ) flours have been correlated to their content of high-molecular-weight glutenin subunits (HMW-GS). The development of a reliable method for genetic transformation has enabled us to make directed modifications in the amounts and composition of these storage proteins by adding genes to wheat that encode a modified HMW-GS. A number of transgenic wheat lines have been obtained in which the accumulation of the introduced gene product is additive to that of the endogenous HMW-GS. However, in one line, addition of HMW-GS genes resulted in partial suppression of endogenous subunit accumulation. Patterns of transgene expression have been stable in homozygous derivatives of these lines for as many as seven generations of growth in the greenhouse. The ability to change the levels and composition of the HMW-GS of wheat seeds by genetic engineering raises the possibility of tailoring flour properties to end-user specifications of dough strength.