Identification of low‐molecular weight glutenin subunits of wheat associated with bread‐making quality

Abstract

Although it is known that the compositions of low-molecular weight glutenin subunits (LMW-GSs) are important factors for bread-making quality of wheat, it is still not clear which LMW-GSs confer improved bread-making quality and how those LMW-GSs interact with highmolecular weight (HMW) GSs. Using a hard red winter wheat line with good bread-making quality and a Japanese wheat cultivar with poor quality as well as their progeny we identified LMW-GSs associated with the bread-making quality. One such LMW-GS, KS2, which had a molecular weight of 42 kDa and was allelic to HS1, was associated with bread-making quality. Furthermore, by using four recombinant inbred lines with different HMW-GS and LMW-GS combinations, KS2 and HMW-GS 5 + 10 showed interaction effects on the bread-making quality. Two-dimensional polyacrylamide gel electrophoresis (PAGE) analysis showed that KS2 consists of two protein components and that HS1 is composed of three components. The N-terminal amino acid sequences of the five components were identical to the most frequently analysed sequence of LMW glutenin components.

Relationship between the Dough Quality and Content of Specific Glutenin Proteins in Wheat Mill Streams, and Its Application to Making Flour Suitable for Instant Chinese Noodles

“…The flour produced from this contains glutenin subunits HMW-GS 5 þ 10 and LMW-GS KS2 that are related to the quality of the dough and endproduct. 8) Wheat cultivar Hokushin was also used for this analysis, since its flour is soft and hence is commonly used for the traditional Japanese udon noodle. These wheat cultivars were grown at the National Agricultural Research Center for Hokkaido Region at Memuro in Hokkaido, Japan in 2003.…”

“…8) A significant improvement in the bread-making quality of soft flour, which can be used only for ''Udon'' noodles and not for bread, has been achieved by blending with appropriate amounts of extra strong types of flour. 19,20) We investigated in this study the correlation between the content of these specific glutenin proteins in a mill stream and the quality of the dough made from each flour mill stream.…”

“…Thus, the properties and amounts of specific proteins such as high-molecularweight and low-molecular-weight glutenin subunits are important for improving the dough and end-product quality. [5][6][7][8][9][10][11][12][13] The milling of wheat grain to produce flour is not achieved in one step, a sequence of many kinds of milling and filtration processes resulting in a large number of fraction mill streams. The final flour is then obtained by combining these various mill streams, so it is valuable for wheat millers and food manufacturers to get information concerning the precise relationship between the specific proteins in a mill stream and both the dough quality and end-product.…”

“…This cultivar, developed for good-quality flour for bread and Chinese noodles, was derived from a cross between the wheat cultivars, Horoshirikomugi, which is a soft flour commercially used for udon noodles, and KS831957. 8) We have already established a proteomic analysis by 2D-PAGE, which enabled us to isolate more than 1,600 protein spots and reveal the qualitative changes among many kinds of wheat-cultivar flour. 21) This system made it possible to measure the amount of the glutenin protein, LMW-GS KS2, that had not previously been identified by SDS-PAGE.…”

Recent Improvements in Japanese Wheat Varieties

“…A combination of glutenin subunits Glu-D1a and Glu-B3g results in extra-strong fl our (Maruyama-Funatsuki et al 2004 ;Tabiki et al 2006 ). 'Yumechikara' is an extra-strong Hard Red Winter wheat cultivar released in 2009 with a marker-assisted selection of these two subunits (Tabiki et al 2011 ).…”