AGRONOMIC BIOCHEMICAL AND QUALITY CHARACTERISTICS OF WHEATS CONTAINING HMW-GLUTENIN TRANSGENES

摘要

Bread dough strength is primarily dependent on its composition of high-molecular-weight glutenin subunits (HMW-GS), a class of storage proteins that typically comprises 5-10% of flour proteins'. We have made a set of transgenic wheats that differ both quantitatively and qualitatively in their HMW-GS compositions. All the transgenics were derived from the cultivar Bobwhite, a hard white spring wheat that contains HMW-GS Ax2*, Bx7, Dx5, By9 and DylO, and also the 1BL/1RS rye translocation. The introduced transgencs included native wheat genes for Dx5 and/or DylO2, or modified genes that encode a Dx5 valiant with an extra-long repeat region3 or a DylO:Dx5 hybrid subunit4. The majority of 28 lines exhibit increases in HMW-GS levels due to additive expression of the transgencs and endogenous genes. However, five lines show transgene-mediated suppression of endogenous HMW-glutenin genes5. In this paper, we present results of a single field trial for 32 different transgenic wheats and mixing characteristics for transgenic wheats that over-express native subunits Dx5 and/or DylO.