Comprehensive identification of LMW-GS genes and their protein products in a common wheat variety

Authors: LEE, JONG-YEOL - National Academy Of Agricultural Science; BEOM, HYE-RANG - National Academy Of Agricultural Science; Altenbach, Susan; LIM, SUN-HYUNG - National Academy Of Agricultural Science; KIM, YEONG-TAE - National Institute Of Crop Science, Iksan, South Korea; KANG, CHON-SIK - National Institute Of Crop Science, Iksan, South Korea; YOON, UNG-HAN - National Academy Of Agricultural Science; GUPTA, RAVI - Andong National University; KIM, SUN-TAE - Pusan National University; AHN, SANG-NAG - Chungnam National University; KIM, YOUNG-MI - National Center For Agriculture And Forestry Technologies (CENTA)

Submitted to: Functional and Integrative Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2016
Publication Date: 2/16/2016
Citation: Lee, J., Beom, H., Altenbach, S.B., Lim, S., Kim, Y., Kang, C., Yoon, U., Gupta, R., Kim, S., Ahn, S., Kim, Y. 2016. Comprehensive identification of LMW-GS genes and their protein products in a common wheat variety. Functional and Integrative Genomics. 16:269-279.

Interpretive Summary: The gluten proteins are responsible for the unique viscoelastic properties that make it possible to produce a wide range of breads, noodles and other baked goods from wheat flour. Among the many and diverse gluten proteins, the low-molecular-weight (LMW)-glutenins are known to affect the processing quality of wheat flour, but it has been difficult to determine the contribution of each individual LMW-glutenin because there are so many proteins with very similar sequences. In this study, 36 LMW-glutenin genes were isolated and sequenced from a single bread wheat cultivar. In parallel, LMW-glutenin proteins in the same cultivar were separated by two-dimensional gel electrophoresis and their protein sequences were determined using mass spectrometry. Gene sequences were then matched to their protein products to provide a comprehensive characterization of LMW-glutenins in a single wheat cultivar. These research results will make it possible for cereal chemists to study the roles of individual LMW-glutenins in flour functional properties and for wheat breeders to apply that information to develop new wheat lines with improved quality.

Technical Abstract: Although it is well known that low-molecular-weight glutenin subunits (LMW-GS) affect bread and noodle processing quality, the function of specific LMW-GS proteins remains unclear. It is important to find the genes that correspond to individual LMW-GS proteins in order to understand the functions of specific proteins. The objective of this study was to link LMW-GS genes and haplotypes characterized using well known Glu-A3, Glu-B3 and Glu-D3 gene specific primers to their protein products in a single wheat variety. A total of 36 LMW-GS genes and pseudogenes were amplified from the Korean cultivar Keumkang. These include 11 Glu-3 gene haplotypes, two from the Glu-A3 locus, two from the Glu-B3 locus and seven from the Glu-D3 locus. To establish relationships between gene haplotypes and their protein products, a glutenin protein fraction was separated by two-dimensional gel electrophoresis (2-DGE) and 17 individual protein spots were analyzed by N-terminal amino acid sequencing and tandem mass spectrometry (MS/MS). LMW-GS proteins were identified that corresponded to all Glu-3 gene haplotypes except the pseudogenes. This is the first report of the comprehensive characterization of LMW-GS genes and their corresponding proteins in a single wheat cultivar. Our approach will be useful to understand the contributions of individual LMW-GS to the end-use quality of flour.