Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/25/2015
Publication Date: 12/29/2015
Citation: Altenbach, S.B., Tanaka, C.K., Whitehand, L.C., Vensel, W.H. 2015. Effects of post-anthesis fertilizer on the protein composition of the gluten polymer in a US bread wheat. Journal of Cereal Science. 68:66-73.
Interpretive Summary: Wheat flour contains a complex mixture of proteins, some of which form large polymers that have been shown to be critical for conferring the unique viscoelastic properties that make it possible to produce a wide range of breads, noodles, pastries and other food products. Both genetic and environmental factors influence the types and amounts of wheat proteins that are able to form these polymers. To better understand how plant growth conditions might influence gluten polymer formation, protein fractions containing small and large polymers were prepared from flour from wheat plants grown in the absence or presence of fertilizer. Individual proteins in each polymer fraction were identified and quantified. The study identifies proteins that change in proportion in the small and large polymer fractions in response to fertilizer, thereby providing important information about how the application of fertilizer might affect the structure of the gluten polymers and influence flour quality.
Technical Abstract: Both genetic and environmental factors influence the types and amounts of wheat proteins that link together to form polymers essential for flour quality. To understand how plant growth conditions might influence gluten polymer formation, protein fractions containing small and large polymers were separated from flour from the US wheat Butte 86 grown in the absence or presence of post-anthesis fertilizer. Proteins in the polymer fractions were analyzed by quantitative two-dimensional gel electrophoresis (2-DE). The ratio of high molecular weight glutenin subunits (HMW-GS) to low molecular weight glutenin subunits (LMW-GS) increased in both fractions in response to fertilizer, due in part to small increases in the proportions of individual HMW-GS. There were also changes within the LMW-GS. In particular, omega and alpha chain terminators increased in proportion in both polymer fractions, but changes were more pronounced in the large polymer fractions. Serpins also increased in both polymer fractions. Additionally, the study revealed differences in the proportions of traditional LMW-GS in small and large polymer fractions. LMW-s type proteins were more abundant in the large polymers while LMW-i type proteins were more prevalent in the small polymers, suggesting that these proteins may play different roles in the gluten polymer.