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Proposal for combining the classification systems of alleles of Gli-1 and Glu-3 loci in bread wheat (Triticum aestivum L.)
Abstract
A new system of nomenclature for the alleles of the genes encoding some gliadin and low molecular weight glutenin (LMW-GS) in bread wheat (Triticum aestivum L.) is suggested. Gliadins encoded by Gli-A1, Gli-B1 and Gli-D1 and LMW-GS encoded by Glu-A3, Glu-B3 and Glu-D3 are described using the following format; Gli-A1, Glu-A3, were is the Gli-1 allele designated by MET-AKOVSKY (1991) and is the Glu-3 allele designated by GUPTA and SHEPHERD (1990). The short hand version of the nomenclature is to use only the gliadin allele e.g. Gli-B1b. However, if there can be more than one Glu-3 allele associated with a particular Gli-1 allele, or vice versa, both alleles should be written e.g. Gli-A1f, Glu-A3a, Gli-B1m, Glu-B3i or Gli-D1b, Glu-D3c. In this publication we have also used the format Gli-A1, Glu-A3. A list of 18 cultivars is given to cover variation found in the set of 49 cultivars studied. The seed of this definite set is available on request.
... The i-, s-and m-type N terminal sequences are found in most of the B-subunits (Tao and Kasarda, 1989;Masci et al., 2002) whereas the C-subunit possess a mixture of true LMW-GS and a-and g-type gliadins. Analysis of the genetic diversity of the LMW-GS was performed on bread wheat (Gupta and Shepherd, 1990;Jackson et al., 1996), on durum wheat, (Ruiz and Carrillo, 1993;Nieto Taladriz et al., 1997) as well as on related species such as T. monococcum and T. urartu (Rodriguez-Quijano et al., 1997;Lee et al., 1999) T tauschii (Gianibelli et al., 2002). Many alleles of LMW-GS have been identified using SDS-PAGE. ...
... Cereal Chem., 5: 222-229. Dubreil L, Biswas SC, Marion D (2002 Branlard G (1996). Genetic characterization of storage proteins in a set of F1-derived haploid lines in bread wheat. ...
... Few grains of each genotype were used for the determination of glutenins composition based on SDS-PAGE as described by Maryami et al. (2020). The glutenins subunits were named following the nomenclature systems developed by Jackson et al. (1996) and Branlard et al. (2003). ...
Wheat dough characteristics and end-use quality are strongly influenced by the amount and specific composition of the glutenins, the major components of gluten. Such proteins are divided into high-molecular-weight glutenins, encoded by the Glu-A1, Glu-B1 and Glu-D1 loci; and low-molecular-weight glutenins, encoded by the Glu-A3, Glu-B3 and Glu-D3 loci. Allelic variation at each of these loci has been associated with changes in wheat functionality. However, most of the studies conducted so far included a relatively limited number of genotypes. Also for this reason, it is still unclear which locus contributes more to dough characteristics and how important are the interactions between the glutenin loci. To try to answer these questions, the quality data of 4623 grain samples derived from 2550 genotypes and generated across 10 years at the CIMMYT bread wheat breeding program, was used to estimate the effect of the glutenin loci and their interactions on gluten quality and bread-making potential. Gluten strength was the trait more strongly influenced by glutenin variations, with the Glu-B1, Glu-D1 and Glu-B3 loci having the greatest effect. Among the glutenin alleles, Glu-A1a, Glu-A1b, Glu-B1al, Glu-B1i, Glu-B1f, Glu-D1d, Glu-A3b, Glu-A3d, Glu-A3f, Glu-B3c and Glu-B3d were associated in general with greater gluten strength, good extensibility and higher bread loaf volume. Differently, alleles Glu-A1c, Glu-B1a, Glu-B1d, Glu-D1a, Glu-A3e and Glu-B3j were associated with an overall poor quality. Glutenin interactions were significantly associated with most of the analyzed quality traits even if their influence was often lower compared to the effect of the single glutenin loci. This is probably the largest study ever done on the effects of the glutenins on wheat quality. The results obtained confirm the importance of such proteins on wheat quality variation and corroborate the usefulness of determining the glutenin profile to improve the selection efficiency for wheat quality in breeding programs.
... The gels were stained using coomasie blue. The glutenins subunits were named following the nomenclature systems developed by Jackson et al. [12] and Branlard et al. [13]. ...
Bread wheat can be used to make different products thanks to the presence of gluten, a protein network that confers unique visco-elastic properties to wheat doughs. Gluten is composed by gliadins and glutenins. The glutenins can be further divided into high and low-molecular-weight glutenins (HMWGs and LMWGs, respectively) and are encoded by Glu-1 and Glu-3 loci. The variability of these genes is associated with differences in quality. Because of this, the identification of novel glutenin alleles is still an important target. In this study, 57 haplotypes or glutenin combinations were registered among a set of 158 Iranian landraces and five novel HMWGs alleles were identified. The landraces were also characterized for several quality traits, including gluten quality, which allowed to associate the different glutenin alleles with low or high quality. Other quality traits examined were iron, zinc, and phytate contents, which are intimately related with the nutritional quality. Important variation for these components was found as well as for the phytate:iron/zinc molar ratios (related to the potential bioavailability of these important micronutrients). The landraces identified in the present study (some of them combining high gluten quality with low phytate:zinc values) could be a useful resource for breeders who aim to improve the wheat end-use quality and especially the content of zinc and its relative bioavailability.
... Thus, it is remarkable that the PCR product always corresponded to genotypes identified by APAGE in this work, not to the name of the cultivar written on the label ( Table 1). The presence of admixtures of alien genotypes in grain samples of wheat and errors in labelling was noted earlier in different wheat collections [19][20][21]. ...
The previously defined pairs of primers GliB1.1 and GliB1.2 were found to produce three and four principal variants, respectively, of PCR sequence length for the γ-gliadin pseudogene in 46 Triticum aestivum L. cultivars from 15 countries carrying 19 known alleles at the Gli-B1 locus. A congruity was established between this polymorphism, allelic sets of the Gli-B1-produced gliadins (especially of the electrophoretic mobility in acid gels of the encoded γ-gliadin) and the presence in the wheat genotype of the Gli-B5b + Rg-1 allelic combination. Six different alleles at the Gli-B1 locus encoding an identical γ-gliadin produced a PCR sequence of about 400 bp (GliB1.1). Nine Gli-B1d-carrying genotypes from four countries produced an identical sequence of about 409 bp (GliB1.2), while three cultivars with Gli-B1h and four with Gli-B1b produced three and two specific sequences, respectively, of slightly different length. Allele Gli-B1j might be the result of recombination between coding and noncoding DNA sequences within the Gli-B1 locus. These observations imply that genetic diversity of the agriculturally important region of chromosome 1B marked by variants of the Gli-B1 locus is rather limited among common wheat cultivars of the 20th century, specifically to eight principal versions. These might have been incorporated into common wheat from diverged genotypes of diploid donor(s), and, due to the scarcity of recombination, subsequently maintained relatively intact. As well as its evolutionary significance, this information is of potential use in wheat breeding and we consider it likely that novel variants of the Gli-B1 locus will be found in hitherto unstudied germplasm.
... Gels were run at 12.5 mA per gel for about 19 h. Glu-1 and Glu-3 alleles were classified using the systems developed by Jackson et al. (1996) and Branlard et al. (2003). ...
Development of biofortified wheat lines has emerged as a sustainable solution to alleviate malnutrition. However, for these varieties to be successful, it is important that they meet the minimum quality criteria required to produce the local food products. In the present study, a set of 94 biofortified common wheat lines were analyzed for their grain micronutrients content (Fe and Zn) and for their processing quality and glutenin profile. Most of the analyzed lines exhibited a grain Zn concentration greater than the non-biofortified check varieties, of at least 3 ppm. The content of both Fe and Zn appeared to be significantly associated with grain protein content (r = 0.21–0.65; p < 0.01) but not with grain yield or other wheat quality traits. Wide allelic variation was observed at both the high-molecular-weight glutenin (HMW-GS) and the low-molecular-weight glutenin (LMW-GS) loci and alleles associated with greater dough strength were identified. Specifically, among the HMW-GS alleles, the Glu-B1i, Glu-B1al, and Glu-D1d alleles were associated with greater mixograph and alveograph values and greater loaf volume. Similarly, among the LMW-GS alleles, the Glu-A3b and Glu-B3b alleles were associated with stronger gluten and better bread-making quality. Overall, results of this study suggest that biofortification does not profoundly alter wheat end-use quality and that the effect of the different glutenin alleles is independent of the grain protein and micronutrient content.
... Arrangement and numbering of HMW-GS in wheat was carried out according [30]. LMW-GS nomenclature in wheat [11] and combined method for LMW-GS and gliadin identification were adopted [16]. ...
... Despite the abundance of LMW-GSs, they have received much less attention than the HMW-GSs, probably due to their complexity, heterogeneity and co-migration with gliadins in SDS-PAGE. In the SDS-PAGE system, gliadins have been used as markers, providing an indirect way to define LMW-GS alleles (Jackson et al. 1996). It has become apparent that the proteomics characterization of LMW-GS extracts is very challenging. ...
... Arrangement and numbering of HMW-GS in wheat was carried out according Payne and Lawrence [5]. LMW-GS nomenclature in wheat [6] and combined method for LMW-GS and gliadin identification were adopted [7]. ...
The low-molecular weight glutenin subunit (LMW-GS) composition of wheat (Triticum aestivum) flour has important effects on end-use quality. However, assessing the contributions of each LMW-GS to flour quality remains challenging because of the complex LMW-GS composition and allelic variation among wheat cultivars. Therefore, accurate and reliable determination of LMW-GS alleles in germplasm remains an important challenge for wheat breeding. In this study, we used an optimized reversed-phase HPLC method and proteomics approach comprising 2-D gels coupled with liquid chromatography–tandem mass spectrometry (MS/MS) to discriminate individual LMW-GSs corresponding to alleles encoded by the Glu-A3, Glu-B3, and Glu-D3 loci in the ‘Aroona’ cultivar and 12 ‘Aroona’ near-isogenic lines (ARILs), which contain unique LMW-GS alleles in the same genetic background. The LMW-GS separation patterns for ‘Aroona’ and ARILs on chromatograms and 2-D gels were consistent with those from a set of 10 standard wheat cultivars for Glu-3. Furthermore, 12 previously uncharacterized spots in ‘Aroona’ and ARILs were excised from 2-D gels, digested with chymotrypsin, and subjected to MS/MS. We identified their gene haplotypes and created a 2-D gel map of LMW-GS alleles in the germplasm for breeding and screening for desirable LMW-GS alleles for wheat quality improvement.
Background and Objectives
The overall goal of this research was to understand the inter‐relationships between wheat quality, grain and flour composition and dough rheology for a range of commercially grown Canadian wheat (Triticum aestivum L.) cultivars (×25) within different wheat market classes.
Findings
Cultivar‐type varied in proximate analyses which directly impacted dough handling parameters. Micro‐doughLAB absorption was positively correlated with protein content, grain hardness, wet gluten and dry gluten content, and was negatively correlated with the gluten performance index. Strong and significant correlation was found between gluten properties, flour composition, and dough strength measurements.
Conclusions
Protein and gluten properties in particular, significantly impacted dough strength measurements. Cultivars displaying stronger gluten strengths may result in dough with better dough handling properties.
Significance and novelty
The study of 25 commercially grown Western Canadian wheat cultivars with a range of gluten strength, and their relation to their glutenin and gliadin subunit composition, and dough handling properties.
Two biotypes of the bread-wheat cultivar Alpe were shown to possess contrasting alleles at each of the glutenin (Glu-B1, Glu-D1, Glu-B3 and Glu-D3) and gliadin (Gli-B1 and Gli-D1) loci on chromosomes 1B and 1D. Fourteen near-isogenic lines (NILs) were produced by crossing these biotypes and used to determine the genetic control of both low-molecular-weight (LMW) glutenin subunits and gliadins by means of one-dimensional or two-dimensional electrophoresis. Genes coding for the B, C and D groups of EMW subunits were found to be inherited in clusters tightly linked with those controlling gliadins. Southern-blot analysis of total genomic DNAs hybridized to a γ-gliadin-specific cDNA clone revealed that seven NILs lack both the Gli-D1 and Glu-D3 loci on chromosome 1D. Segregation data indicated that these "null" alleles are normally inherited. Comparison of the "null" NILs with those possessing allele b at the Glu-D3 locus showed one B subunit, seven C subunits and two D subunits, as fractionated by two-dimensional A-PAGExSDS-PAGE, to be encoded by this allele. Alleles b and k at Glu-B3 were found to code for two C subunits plus eight and six B subunits respectively, whereas alleles b and k at Gli-B1 each controlled the synthesis of two β-gliadins, one γ and two ω-gliadins. The novel Gli-B5 locus coding for two ω-gliadins was shown to recombine with the Gli-B1 locus on chromosome 1B. The two-dimensional map of glutenin subunits showed α-gliadins encoded at the Gli-A2 locus on chromosome 6A. The use of Alpe NILs in the study of the individual and combined effects of glutenin subunits on dough properties is discussed.
Co-segregation of alleles of the beta-amylase gene β-Amy-D1 and one of the proteins described as a high molecular weight albumin present in the wheat endosperm, along with a number of shared biochemical characteristics, shows that they represent an identical class of proteins, and are thus the products of a single gene.
Alkylated glutenin subunits of F7 progenies from the cross between the Italian bread wheat cultivar Costantino and the Canadian cultivar Neepawa were fractionated by one-dimensional A-PAGE and SDS-PAGE and by two-dimensional A-PAGE × SDS-PAGE. Each gliadin allele at the Gli-1 loci of the parental cultivars was shown to be associated with a specific allele at each of the Glu-3 loci, at which low Mr glutenin subunits are encoded. The Glu-A3 locus was found to code for two low Mr subunits in Neepawa and three in Costantino. In this latter cultivar, eight low Mr subunits were assigned to each of the Glu-B3 and Glu-D3 loci, whereas seven subunits were attributed to the Glu-B3 locus and seven to the Glu-D3 locus in Neepawa. A-PAGE × SDS-PAGE can be employed for a detailed description of low Mr subunits of glutenin in different cultivars following a genetic approach based on the correspondence between the alleles at the Gli-1 and Glu-3 loci.
Gli-D1-encoded omega gliadins of bread wheats show little variation; their electrophoretic patterns can be classified into two main groups which broadly resemble the patterns found in the cultivars Chinese Spring and in Cheyenne. B and D subunits of low molecular weight glutenin encoded by the chromosome 1D loci Glu-D3 and Gli-D1, respectively, also showed little variation. D subunits were found only in bread wheats with "Chinese Spring-type" omega gliadins and they all exhibited the same electrophoretic pattern. This material also showed very similar B subunits. "Cheyenne-type" bread wheats displayed the same electrophoretic distribution of chromosome 1D-encoded B subunits, although they were slightly different from that found in Cheyenne itself.