The composition of high-molecular-weight-glutenin subunits (HMW-GS) is a key determinant of wheat baking properties. These subunits are encoded by the GLU-A1, GLU-B1, and GLU-D1 loci on the long arm of chromosome 1 and consist of x- and y-type subunits. Allelic variations in composition are a major factor influencing bakery quality. Unlike sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) or ultra-performance liquid chromatography (UPLC), which often fail to resolve closely related allelic variants, PCR-based markers allow for clear and definitive discrimination at the DNA level. Building on the results of a previous study that determined the GLU-B1 allele composition, we aimed to confirm—through the use of PCR markers—the allele compositions of GLU-A1 and GLU-D1 in 44 domestic wheat varieties. The results showed that “Jonong” and “Sinmichal1” contained the Glu-A1b (A1x2*) allele rather than Glu-A1a (A1x1) or Glu-A1c (A1x-null). Additionally, “Jonong” and “Sinmichal1” exhibited the allelic composition Glu-D1a (D1x2+D1y12), rather than Glu-D1d (D1x5+D1y10) or Glu-D1f (D1x2.2+D1y12). These results were compared with those obtained by SDS-PAGE and UPLC. The PCR-based markers used to identify GLU-A1 and GLU-D1 alleles in this study will be valuable for determining the allelic composition at the GLU-A1 and GLU-D1 loci in domestic wheat varieties. Furthermore, the re-evaluated genetic composition is expected to improve the precision of assessments related to the baking quality of domestic wheat.

Wheat is a fundamental staple crop worldwide, contributing significantly to global food security due to its versatility and nutritional value. However, gluten proteins, including gliadins and glutenins, have been implicated in various health problems, such as celiac disease, non-celiac gluten sensitivity, and wheat allergies. These disorders affect a wide variety of people globally, creating demand for wheat varieties that balance high-end-use quality with reduced immunogenic potential. This review examines the molecular and genetic mechanisms that regulate gluten protein synthesis, highlighting recent advances in genomic and mutagenic approaches aimed at modifying gluten proteins to enhance the health and quality traits of wheat. Technologies such as RNAi and CRISPR/Cas9 offer promising avenues for reducing wheat immunogenicity without compromising its functional properties in food production. This study also examines the challenges and prospects of utilizing these genetic tools to develop wheat varieties that achieve the dual
objective
s of enhanced health outcomes and high product quality.

In common wheat (Triticum aestivum L.), the protein content and glutenin protein composition are the key quality-determining parameters. Allelic variations, especially in high-molecular-weight glutenin subunits (HMW-GSs), affect bread quality significantly. The HMW-GS Glu-1 locus consists of two tightly linked genes encoding x- and y-type subunits that exhibit highly variable frequencies. In this study, we evaluated Glu-B1 alleles using allele-specific PCR markers in 44 domestic wheat cultivars. The composition of Glu-1Bx7+Glu-1By8 in the 24 cultivars was either Glu-1Bx7+Glu-1By8, Glu-1Bx7*+ Glu-1By8, or Glu-1Bx7*+Glu-1Bx8*. In addition, the two cultivars initially identified Glu- 1Bx7+Glu-1By8* were corrected to Glu-1Bx7*+Glu-1By8*. Seven cultivars previously classified as having Glu-1Bx7+Glu-1By9 composition contained Glu-1Bx7*+ Glu-1Bx9. The allele composition of the cultivar was identified as Glu-1Bx20+Glu-1By20 instead of Glu-1By20. The HMW-GSs of 21 wheat varieties were analyzed using ultra-performance liquid chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results will be helpful for evaluating the composition of Glu-B1 alleles in domestic wheat and accurately assessing the quality of domestic wheat flour.

AbstractThe high-molecular-weight glutenin subunit (HMW-GS) composition of wheat is the main factor controlling gluten strength related to bread baking quality. Reported molecular markers for HMW-GS were validated and selected for improved breeding efficiency in South Korean wheat breeding programs. Sodium dodecyl sulfate polyacrylamide gel electrophoresis, lab-on-a-chip electrophoresis, sequence-tagged site (STS) markers, and Kompetitive Allele-Specific PCR were performed to re-evaluate the known HMW-GS of 14 wheat cultivars. Glu-A1b and Glu-A1c alleles were separated by the STS marker, UMN19, and KASP marker, namely Glu-Ax1/2*_SNP, at Glu-1 loci. At the Glu-B1 locus, Glu1-By8 and Glu1-By9 could be distinguished from Glu-B1b and Glu-B1c alleles by two STS markers, namely ZSBy8 and ZSBy9a, respectively. Glu1-Bx17 and Glu1-7^OE could respectively be separated from non-Glu-B1i and non-Glu-B1al alleles by cauBx642 and BX7^OE_866_SNP. The Glu-D1d allele, used to determine bread baking quality, could easily be distinguished from other alleles by Glu-D1d_SNP at Glu-D1 loci. Validated molecular markers in this study could therefore be used to select wheat lines for good bread baking quality in South Korean wheat breeding programs.

Wheat is one of major crop and wheat flour is used to various end-use products such as bread, cookies and noodles due to its unique characteristic of it as elasticity and viscosity. Wheat consumption has been generally increasing in not only US and Europe but also Korea. Nevertheless, gluten proteins in wheat endosperm are cause of allergy by food ingestion. Hence, studies on the allergy have been conducting and have been attracting public attention. Herein, we report studies on research trend of the issue with research papers over the last decade for suggestion of future research direction. Since 2012, studies on allergy of gluten proteins have been dramatically increased based on the number of published papers related to the issue. As results of research activities by country, the Europe accounted for 60% corresponding to the number of papers. Next US (13%), Japan (9%), China (5%), and Korea (2%) came. In Korea, studies on allergy of gluten protein are less studied. In the field of studying of gluten allergy, there are two major technologies as preclinical technology and genome research accounted for 58% and 26%, respectively. In Korea, the study on glutenin proteins which is closely related to wheat allergy is actively performed. Therefore, it can be expected that research will be become more active.

This study is to raise the utilization of genetic resources of wheat (Triticum aestivum L.) landrace from East Asia (Korea, Japan, and China) by evaluating genetic variation related to end use quality concerned to bread making quality and early maturity, two very important characteristics of Korean wheat cropping system. To clarify the allelic variation of Glu-1 loci which decides HMW glutenin subunit composition, SDS-PAGE and DNA marker analysis were conducted by using 485 East Asian landrace wheat accessions in National Agrobiodiversity Center, RDA and NIAS genebank. And useful accessions getting full mark of glu-1 score and early maturity were selected to enhance the utilization of genetic resources to Korean wheat breeding.

In this study, wheats from China showed the distinct characteristic. Whereas Glu-A1c (null) and Glu-B1b (7+8) allele are the most frequent in Korean and Japanese accessions, Glu-A1a (2^*) and Glu-B1c (7^*+9) are the most in Chinese accessions. When it comes to unique composition, Glu-B1f (13+16) and Glu-D1e (2+10) subunits are only in Chinese resources. Glu-B1d (6+8), Glu-B1e (20), Glu-D1b (7+8), and Glu-D1c (4+1) subunits are only in Korean resources. The accessions from China also has high PIC value (0.53) compared to ones from Korea (0.35) and Japan (0.35). Grouping by UPGMA analysis of combination of Glu-1 allele, most accessions from Korea and Japan are in the same group, but most Chinese ones were distinguished as the distinctive group. The evaluation of bread baking quality by Glu-1 scoring system, 26 accessions got full marks. Among them, 16 accessions from China were also matured before early June, suitable to Korean cropping system. Especially, 3 accessions (K151847, K151865, K151962) had very early maturity, matured in late May. These genetic resources, having good gluten composition and early maturity, are expected to widely be used for Korean wheat breeding.

Low-molecular-weight glutenin subunits (LMW-GS) play a crucial role in the processing quality of wheat flour. They are encoded multi gene family located at the Glu-A3, Glu-B3 and Glu-D3 on the short arm of chromosome 1A, 1B and 1D respectively. Typical LMW-GSs are composed of three parts including a short N-terminal domain, a relatively short repetitive domain and a C-terminal domain. Further, typical LMW-GS sequences are divided into LMW-s, LMW-m and LMW-i types, on the basis of the first amino acid of the mature proteins (serine, methionine and isoleucine, respectively). Although it is known that the allelic variation of LMW-GSs affect the properties of dough, it is still not clear which LMW-GSs confer better bread-making quality because of the larger number of expressed subunits and their overlapping mobility with abundant gliadin proteins. Therefore, it is important to characterize LMW-GS genes and develop functional markers to identify different LMW-GS alleles for application in wheat breeding. In this review, we discuss the various aspects of LMW-GS, including their structural characteristics, the development of marker, relationship between LMW-GSs and bread wheat quality, and genetic engineering of the LMW-GSs.