Allelic variations in <Emphasis Type="Italic">Glu-1</Emphasis> and <Emphasis Type="Italic">Glu-3</Emphasis> loci of historical and modern Iranian bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) cultivars

Proline and glutamine-rich wheat seed endosperm proteins are collectively referred to as prolamins. They are comprised of HMW-GSs, LMW-GSs and gliadins. HMW-GSs are major determinants of gluten elasticity and LMW-GSs considerably affect dough extensibility and maximum dough resistance. The inheritance of glutenin subunits follows Mendelian genetics with multiple alleles in each locus. Identification of the banding patterns of glutenin subunits could be used as an estimate for screening high quality wheat germplasm. Here, by means of a two-step 1D-SDS-PAGE procedure, we identified the allelic variations in high and low-molecular-weight glutenin subunits in 65 hexaploid wheat (Triticum aestivum L.) cultivars representing a historical trend in the cultivars introduced or released in Iran from the years 1940 to 1990. Distinct alleles 17 and 19 were detected for Glu-1 and Glu-3 loci, respectively. The allelic frequencies at the Glu-1 loci demonstrated unimodal distributions. At Glu-A1, Glu-B1 and Glu-D1, we found that the most frequent alleles were the null, 7 + 8, 2 + 12 alleles, respectively, in Iranian wheat cultivars. In contrast, Glu-3 loci showed bimodal or trimodal distributions. At Glu-A3, themost frequent alleles were c and e. At Glu-B3 the most frequent alleles were a, b and c. At Glu-D3 locus, the alleles b and a, were the most and the second most frequent alleles in Iranian wheat cultivars. This led to a significantly higher Nei coefficient of genetic variations in Glu-3 loci (0.756) as compared to Glu-1 loci (0.547). At Glu-3 loci, we observed relatively high quality alleles in Glu-A3 and Glu-D3 loci and low quality alleles at Glu-B3 locus.     

Allelic variation of high molecular weight glutenin subunits of bread wheat in Hebei province of China

In common wheat (Triticum aestivum L.), allelic variations of Glu-1 loci have important influences on grain end-use quality. The allelic variations in high molecular weight glutenin subunits (HMW-GSs) were identified in 151 hexaploid wheat varieties representing a historical trend in the cultivars introduced or released in Hebei province of China from the years 1970s to 2010s. Thirteen distinct alleles were detected for Glu-1. At Glu-A1, Glu-B1 and Glu-D1, we found that the most frequent alleles were the 1 (43.0%), 7+8 (64.9%), 2+12 (74.8%) alleles, respectively, in wheat varieties. Twenty two different HMW-GS compositions were observed in wheat. Twenty-five (16.6%) genotypes possessed the combination of subunits 1, 7+8, 2+12, 25 (16.6%) genotypes had subunit composition of 2*, 7+8, 2+12; 20 (13.2%) genotypes had subunit composition of null, 7+8, 2+12. The frequency of other subunit composition was less than 10%. The Glu-1 quality score greater than or equal to 9 accounted for 20.6% of the wheat varieties. The percentage of superior subunits (1 or 2* subunit at Glu-A1 locus; 7+8, 14+15 or 17+18 at Glu-B1 locus; 5+10 or 5+12 at Glu-D1 locus) was an upward trend over the last 40 years. The more different superior alleles correlated with good bread-making quality should be introduced for their usage in wheat improvement efforts.     

西南冬麦区地方品种HMW-GS组成遗传多样性研究

采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)对西南冬麦区(云南、贵州、四川)3个省份共计560份小麦地方品种的高分子量谷蛋白亚基(HMW-GS)组成进行了研究。结果表明:Glu-1位点共有22种等位基因,其中Glu-A1位点4种、Glu-B1位点11种、Glu-D1位点7种;亚基null、7 8和2 12在各自位点的频率最高,分别为89.64%、68.21%和96.43%。亚基组成类型共有46种,以null/7 8/2 12和null/7 9/2 12为主,频率分别为50.89%和11.79%。在这些材料中筛选出一些含有1、2*、17 18、14 15、5 10等优质亚基的材料,其中有52份材料含有优质亚基组合。     

Characterization of a novel y-type high molecular weight glutenin subunit at <Emphasis Type="Italic">Glu-D1</Emphasis> locus

Glu-D1y12.K as a novel y-type subunit was found in HMW-GSs encoded at the Glu-D1 locus in the JB20, which a Korean wheat line from F₉ lines crossed by Keumkang with Glu-D1d and Chinese Spring (CS) with Glu-D1a alleles. This novel subunit shows faster electrophoretic mobility and lower molecular weight than Dy12 subunit on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The result of linear ion-trap and Fourier-transform mass spectrometry (LTQ-FT-MS) based on two-dimensional electrophoresis (2-DE) showed that the Dy12.K subunit has high similarity against protein ID: P08488 (GLT3_WHEAT) as ‘Glutenin, high molecular weight subunit 12’ form UniProtKB. The gene of the Glu-1Dy12.K subunit is composed of 1962 nucleotide base pairs containing open reading frame (ORF) as 652 amino acids corresponding to about 70.1 kDa. It has four indels (36 bp insertions: two repeated 18 and 24 bp deletion: two deletions with 6?+?18 bp) and 21 SNPs compared to Glu-1Dy10 (GI: 164457872 in NCBI), and one deletion (18 bp) and three SNPs compared to Glu-1Dy12 (GI: 1036031968) by DNA markers. Consequentially, in comparison with Dy10, 13 SNPs were non-synonymous SNPs and eight SNPs were synonymous SNPs of 21 SNPs. In comparison with Dy12, only one SNP was non-synonymous SNP of three SNPs. Furthermore, the deduced peptide sequences as ‘TGQGQQ’ corresponding to ‘AACAGGACAAGGGCAACA’ are deleted only in the Dy12.K subunit.     

Multiplex PCR identification of wheat HMW glutenin subunit genes by allele-specific markers

Wheat bread-making quality is closely correlated with composition and quantity of gluten proteins, in particular with high-molecular weight (HMW) glutenin subunits encoded by the Glu-1 genes. A multiplex polymerase chain reaction (PCR) method was developed to identify the allele composition of HMW glutenin complex Glu-1 loci (Glu-A1, Glu-B1 and Glu-D1) in common wheat genotypes. The study of multiplex PCR to obtain a well-balanced set of amplicons involved examination of various combinations of selected primer sets and/or thermal cycling conditions. One to three simultaneously amplified DNA fragments of HMW glutenin Glu-1 genes were separated by agarose slab-gel electrophoresis and differences between Ax1, Ax2* and Axnull genes of Glu-A1 loci, Bx6, Bx7 and Bx17 of Glu-B1, and Dx2, Dx5 and Dy10 genes of Glu-D1 loci were revealed. A complete agreement was found in identification of HMW glutenin subunits by both multiplex PCR analysis and SDS-PAGE for seventy-six Polish cultivars/strains of both spring and winter common wheat. Rapid identification of molecular markers of Glu-1 alleles by multiplex PCR can be an efficient alternative to the standard separation procedure for early selection of useful wheat genotypes with good bread-making quality.     

Relationship of HMW, LMW Glutenin Subunits and γ-gliadins with Gluten Strength in Indian Durum Wheats

Twenty-four durum wheat genotypes were evaluated for two years to assess the relationship between HMWglutenin subunits, LMWB glutenin patterns, gammagliadins and gluten strength as measured by SDS-sedimentation volume. Indian durum genotypes assessed in this study represented a diverse set of Glu-1, GH-B1 and Glu-3 alleles. Considerable variability was detected for protein content and gluten strength. All the locals and released varieties derived from locals showed significantly higher protein content. Specific alleles at Glu-1, Glu-3 and Gli-B1 loci showed different effects on gluten strength. HMW glutenin subunits 2^* and 14+15 showed association with high gluten strength. Genotypes having LMW-f (linked γ-43.5) showed significantly higher gluten strength than other three LMW-B patterns, i.e. LMW-b and c (linked γ-45) and LMW-e(linked γ-44). While genotypes with γ-44 and linked LMW-e patterns were found to have lowest gluten strength. The Gli-A2 locus did not show any significant association with gluten strength.     

Molecular Characterization of a HMW Glutenin Subunit Allele Providing Evidence for Silencing of x-type Gene on Glu-B1

Understanding the molecular structure of high-molecular-weight glutenin subunit (HMW-GS) may provide useful evidence for the study on the improvement of quality of cultivated wheat and the evolution of Glu-1 alleles. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) shows that the subunits encoded by Glu-B1 were null, named 1Bxm, in a Triticum turgidum var. dicoccoides line PI94640. Primers based on the conserved regions in wheat HMW-GS gene promoter and coding sequences were used to amplify the genomic DNA of line PI94640. The PCR products were sequenced, and the total nucleotide sequence of 3 442 bp including upstream sequence of 1 070 bp was obtained. Compared with the reported gene sequences of Glu-1Bx alleles, the promoter region of the Glu-1Bxm showed close resemblance to 1Bx7. The Glu-1Bxm coding region differs from the other Glu-1Bx alleles for a deduced mature protein with only 212 residues, and a stop codon (TAA) at 637 bp downstream from the start codon was present, which was probably responsible for the silencing of x-type subunit genes at the Glu-B1 locus. Phylogenetic tree based on the nucleotide sequence alignment of HMW glutenin subunit genes showed that 1Bxm was the most ancient type of Glu-B1 alleles, suggesting that the evolution rates are different among Glu-1Bx genes. Further study on the contribution of the unique silenced Glu-B1 alleles to quality improvement was also discussed.     

Characterization of a novel variant HMW-glutenin gene from Elymus canadensis

High molecular weight (HMW) glutenin subunits (GS) play a key role in the determination of end-use quality of wheat and other cereal crops. In this study, we report the isolation and characterization of both promoter region and ORF of novel HMW-GS allele 1St1.3 from a perennial Triticeae species, Elymus canadensis. The amino acid (AA) sequences of E. canadensis 1St1.3 were deduced as 434 aa. Its protein primary structure comprises a signal peptide with a conserved N-terminal domain, a central repetitive domain and a C-terminal domain. E. canadensis 1St 1.3 possesses several distinct characteristics which are different from those of wheat HMW-GSs. The N-terminal domains of E. canadensis 1St 1.3 resemble that of y-type subunits, while their C-terminal domains are more similar to x-type subunits. The deletion of 85 bp fragment has been observed in promoter region of 1St 1.3, however which has not interrupted the expression of this gene. Our results indicate that 1St 1.3 is novel HMW-GS variants which will be valuable for enhancing our understanding of structural differentiation and the evolutionary relationship among HMW-GSs in Triticeae species.     

Allelic variation of high-molecular-weight glutenin genes in bread wheat

The composition and quantity of high-molecular-weight glutenin subunits plays an important role in determining the bread-making quality of wheat. Molecular-genetic analysis of allelic composition of high-molecular-weight glutenin genes in 102 bread wheat cultivars and lines from different geographical regions was conducted. Three alleles at the Glu-A1 locus, nine alleles at the Glu-B1 locus, and two alleles at the Glu-D1 locus were identified. Among the investigated cultivars and lines, 21 were characterized by intracultivar polymorphism. High allelic variation of high-molecular-weight glutenin subunit genes was shown for the collection: 21 and 9 combinations were defined in monomorphic and polymorphic cultivars and lines, respectively. However, the major part of the collection (66.7%) contained four allelic combinations: Glu-A1b Glu-B1c Glu-D1d, Glu-A1b Glu-B1c Glu-D1-2a, Glu-A1a Glu-B1c Glu-D1d, and Glu-A1b Glu-B1c Glu-D1d/Glu-D1-2a. Fourteen cultivars of bread wheat were selected, and they were characterized by a favorable allelic composition of Glu-1 loci.     

ChAy/Bx, a novel chimeric high-molecular-weight glutenin subunit gene apparently created by homoeologous recombination in Triticum turgidum ssp. dicoccoides

High-molecular-weight glutenin subunits (HMW-GSs) are of considerable interest, because they play a crucial role in determining dough viscoelastic properties and end-use quality of wheat flour. In this paper, ChAy/Bx, a novel chimeric HMW-GS gene from Triticum turgidum ssp. dicoccoides (AABB, 2n = 4x = 28) accession D129, was isolated and characterized. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed that the electrophoretic mobility of the glutenin subunit encoded by ChAy/Bx was slightly faster than that of 1Dy12. The complete ORF of ChAy/Bx contained 1671 bp encoding a deduced polypeptide of 555 amino acid residues (or 534 amino acid residues for the mature protein), making it the smallest HMW-GS gene known from Triticum species. Sequence analysis showed that ChAy/Bx was neither a conventional x-type nor a conventional y-type subunit gene, but a novel chimeric gene. Its first 1305 nt sequence was highly homologous with the corresponding sequence of 1Ay type genes, while its final 366 nt sequence was highly homologous with the corresponding sequence of 1Bx type genes. The mature ChAy/Bx protein consisted of the N-terminus of 1Ay type subunit (the first 414 amino acid residues) and the C-terminus of 1Bx type subunit (the final 120 amino acid residues). Secondary structure prediction showed that ChAy/Bx contained some domains of 1Ay subunit and some domains of 1Bx subunit. The special structure of this HMW glutenin chimera ChAy/Bx subunit might have unique effects on the end-use quality of wheat flour. Here we propose that homoeologous recombination might be a novel pathway for allelic variation or molecular evolution of HMW-GSs.     

Molecular characterization of two y-type high molecular weight glutenin subunit alleles 1Ay12 and 1Ay8 from cultivated einkorn wheat (Triticum monococcum ssp. monococcum)

Two y-type high molecular weight glutenin subunits (HMW-GSs) 1Ay12^? and 1Ay8^? from the two accessions PI560720 and PI345186 of cultivated einkorn wheat (Triticum monococcum ssp. monococcum, AA, 2n = 2x = 14), were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The mobility of 1Ay12^? and 1Ay8^? was similar to that of 1Dy12 and 1By8 from common wheat Chinese Spring, respectively. Their ORFs respectively consisted of 1812 bp and 1935 bp, encoding 602 and 643 amino acid residues with the four typical structural domains of HMW-GS including signal peptide, conserved N-, and C-terminal and central repetitive domains. Compared with the most similar active 1Ay alleles previous published, there were a total of 15 SNPs and 2 InDels in them. Their encoding functions were confirmed by successful heterogeneous expression. The two novel 1Ay alleles were named as 1Ay12^? and 1Ay8^? with the accession No. JQ318694 and JQ318695 in GenBank, respectively. The two alleles were classed into the two distinct groups, Phe-type and Cys-type, which might be relevant to the differentiation of Glu-A1-2 alleles. Of which, 1Ay8^? belonged to Cys-type group, and its protein possessed an additional conserved cysteine residue in central repetitive region besides the six common ones in N- and C-terminal regions of Phe-type group, and was the second longest in all the known active 1Ay alleles. These results suggested that the subunit 1Ay8^? of cultivated einkorn wheat accession PI345186 might have a potential ability to strengthen the gluten polymer interactions and be a valuable genetic resource for wheat quality improvement.     

Large-scale expression and purification of high-molecular-weight glutenin subunits

The high-molecular-weight glutenin subunits (HMW-GSs) are considered to be one of the most important components of wheat gluten, contributing to the unique viscoelastic properties of wheat dough. The HMW-GSs are highly homologous in sequence and structure and a mixture of subunits is usually present in wheat flours. Consequently, it is difficult to purify these proteins separately in appreciable amounts. Expression in heterologous systems provides a clear opportunity to produce large amounts of single HMW-GS proteins, amounts (up to 100 mg) which are required for in vitro analysis of these proteins. However, since the first expression studies of HMW-GSs, over 10 years ago, this technology has not been widely utilized. Previous studies have been analytical or small scale (5-100 ml) and in most cases only partial purity was obtained. In the present paper, we describe in detail the expression of the HMW-GSs Glu1-Dx2, Dx5, Dy10, and Dy12 for the first time on a large scale, producing up to 100 mg of target protein from a 2-liter bacterial culture, using a Biostat fermenter. Our results include optimization of expression conditions to increase yield and stability of proteins. Results also include localization, differences between x- and y-type expression and small-scale versus large-scale expression. We also developed a large-scale purification procedure. The bacterially expressed proteins have the same molecular weight on SDS-PAGE and the same retention times on RP-HPLC as their native counterparts extracted from flour. Functionality tests, on the bacterially produced proteins, have shown a clear correlation with the equivalent native proteins from flour. These results provide a clear opportunity to produce protein in amounts necessary for more detailed studies of the structure and function of the HMW-GSs and glutenin polymers on dough development and quality.     

Mitotic illegitimate recombination is a mechanism for novel changes in high-molecular-weight glutenin subunits in wheat-rye hybrids

Wide hybrids can have novel traits or changed expression of a quantitative trait that their parents do not have. These phenomena have long been noticed, yet the mechanisms are poorly understood. High-molecular-weight glutenin subunits (HMW-GS) are seed storage proteins encoded by Glu-1 genes that only express in endosperm in wheat and its related species. Novel HMW-GS compositions have been observed in their hybrids. This research elucidated the molecular mechanisms by investigating the causative factors of novel HMW-GS changes in wheat-rye hybrids. HMW-GS compositions in the endosperm and their coding sequences in the leaves of F(1) and F(2) hybrids between wheat landrace Shinchunaga and rye landrace Qinling were investigated. Missing and/or additional novel HMW-GSs were observed in the endosperm of 0.5% of the 2078 F(1) and 22% of 36 F(2) hybrid seeds. The wildtype Glu-1Ax null allele was found to have 42 types of short repeat sequences of 3-60 bp long that appeared 2 to 100 times. It also has an in-frame stop codon in the central repetitive region. Analyzing cloned allele sequences of HMW-GS coding gene Glu-1 revealed that deletions involving the in-frame stop codon had happened, resulting in novel ～1.8-kb Glu-1Ax alleles in some F(1) and F(2) plants. The cloned mutant Glu-1Ax alleles were expressed in Escherichia coli, and the HMW-GSs produced matched the novel HMW-GSs found in the hybrids. The differential changes between the endosperm and the plant of the same hybrids and the data of E. coli expression of the cloned deletion alleles both suggested that mitotic illegitimate recombination between two copies of a short repeat sequence had resulted in the deletions and thus the changed HMW-GS compositions. Our experiments have provided the first direct evidence to show that mitotic illegitimate recombination is a mechanism that produces novel phenotypes in wide hybrids.     

Characterization of HMW-GSs and their gene inaction in tetraploid wheat

In this study, we report the expression of HMW-GSs in 87 accessions of tetraploid wheat, the characterization of three inactive and one active HMW glutenin genes, and the functional verification of HMW-GSs by promoter–GUS expression. SDS-PAGE profiles revealed that tetraploid wheat has many different combinations of HMW-GSs and the number of subunits varies from 1 to 4. HMW glutenin genes at the Glu-A1x, Glu-A1y and Glu-B1y loci exhibited different frequencies of inaction while the Glu-B1x allele was expressed in all 87 accessions. Gene cloning showed that only 1Bx (Tdu-e) could express a full-length protein and its deduced protein sequence has the typical primary structure but with fewer cysteine residues. The expression of the other three HMW glutenin genes has been disrupted by stop codons in their repetitive domains. Besides short indels or mutations of one or more bases, an 85-bp deletion and a 185-bp insertion were found in the promoter regions of 1Ay (Tdu-s) and 1Bx (Tdu-e). The transient expression of promoter–GUS constructs indicated that the 1Ay promoter can drive expression of the GUS gene. We conclude that defects (stop codons or the insertion of large transposon-like elements) in the coding regions may be the most probable cause for the inaction of the HMW glutenin genes.     

Genetic Diversity of Gli-1, Gli-2 and Glu-1 Alleles in Sichuan Wheat Landraces

Genetic diversity at Gli-1, Gli-2 and Glu-1 loci was investigated in 89 Sichuan wheat ( Triticum aestivum L.) landraces by using acid polyacrylamide gel electrophoresis (APAGE) and SDS-PAGE. In these landraces, a total of 32 gliadin and 3 high-molecular-weight (HMW) glutenin patterns were observed. In total, 14, 15 and 5 alleles were identified at Gli-1, Gli-2 and Glu-1, respectively. At each locus, the alleles in higher frequency were Gli-A1a (89%), Gli-B1 h (46%), Gli-D1a (65%), Gli-A2a (64%), Gli-B2j (45%), Gli-D2 a (48%), Glu-A1c (99%), Glu-B1b (99%) and Glu-D1a (100%). The Nei's genetic variation index (H) of Sichuan wheat landraces was 0.3706, varying from 0 to 0.7087. The highest genetic diversity was found at Gli-B2 locus, while the lowest was found at Glu-D1 . The genetic diversity at Gli loci was higher than that of Glu-1 loci among these landraces, but it was much lower than that of modern wheat cultivars. These results indicated a narrow genetic base of Sichuan wheat landraces. In this study, “Chengdu-guangtou” had the identical gliadin and HMW-glutenin patterns with “Chinese Spring”, further supporting the proposal that “Chinese Spring” is a strain of “Chengdu-guangtou”.     

带芒草属物种新型高分子量谷蛋白亚基的鉴定

采用SDSPAGE方法对牧草带芒草属3个种8份材料的高分子量谷蛋白进行了检测和鉴定。结果显示,带芒草物种具有的高分子量谷蛋白亚基与普通小麦中发现的不一样,其迁移率存在较大差异。其中,x型亚基均比Dx2亚基迁移率小或接近,y型亚基均比Dx12亚基迁移率大。8份材料中共发现了4种x型亚基新类型(Tax1,Tax2,Tax3和Tax4),5种y型亚基新类型(Tay1,Tay2,Tay3,Tay4和Tay5)和6种亚基组合类型(Tax1+Tay3,Tax3+Tay2,Tax4+Tay1,Tax1+Tay1,Tax2+Tay5,Tax4+Tay2),该项研究结果揭示了带芒草属植物可能具有与普通小麦类似的高分子量谷蛋白亚基,这些亚基在小麦品质遗传改良中具有潜在的利用价值。     

Analysis of diversity of russian and Ukrainian bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) cultivars for high-molecular-weight glutenin subunits

The allelic diversity of high-moleculat-weght glutenin subunits (HMWGS) in Russian and Ukrainian bread wheat cultivars was analyzed. The diversity of spring wheat cultivars for alleles of the Glu-1 loci is characterized by medium values of the polymorphism polymorphism information content (PIC), and in winter wheats it varies from high at the Glu-A1 locus to low at the Glu-D1 locus. The spring and winter cultivars differ significantly in the frequencies of alleles of the glutenin loci. The combination of the Glu-A1b, Glu-B1c, and Glu-D1a alleles prevails among the spring cultivars, and the combination of the Glu-A1a, Glu-B1c, and Glu-D1d alleles prevails among the winter cultivars. The distribution of the Glu-1 alleles significantly depends on the moisture and heat supply in the region of origin of the cultivars. Drought resistance is associated with the Glu-D1a allele in the spring wheat and with the Glu-B1b allele in the winter wheat. The sources of the Glu-1 alleles were identified in the spring and wheat cultivars. The analysis of independence of the distribution of the spring and winter cultivars by the market classes and by the alleles of the HMWGS loci showed a highly significant association of the alleles of three Glu-1 loci with the market classes in foreign cultivars and independence or a weak association in the Russian and Ukrainian cultivars. This seems to be due to the absence of a statistically substantiated system of classification of the domestic cultivars on the basis of their quality.     

Characterization and comparative analysis of HMW glutenin 1Ay alleles with differential expressions

Background  

High-molecular-weight glutenin subunits (HMW-GSs) have been considered as most important seed storage proteins for wheat flour quality. 1Ay subunits are of great interest because they are always silent in common wheat. The presence of expressed 1Ay subunits in diploid and tetraploid wheat genotypes makes it possible to investigate molecular information of active 1Ay genes.     

Molecular profiling of a y-type high molecular weight glutenin subunit at <Emphasis Type="Italic">Glu-D1</Emphasis> locus from a North Korean landrace wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The objective of this study is to demonstrate characteristics of a y-type high molecular weight glutenin subunit (D1y HMW-GS) at Glu-D1 found in IT212991, a North Korean landrace wheat compared to Dy12 and Dy12.K as a novel HMW-GS in JB20, a Korean wheat line onto molecular analyses as PCR, cloning, DNA sequencing, and RP-HPLC and proteomic analyses as sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE), two-dimensional electrophoresis (2-DE), Fourier-transform mass spectrometry (LTQ-FT-MS). The D1y of IT212991 was identified to have faster electrophoretic mobility than that of Dy12 by SDS–PAGE. HMW-GS components of IT212991 were identified to be different from Chinese Spring (CS) and JB20, a Korean wheat line by RP-HPLC. The result of mass spectrometric analysis, the D1y of IT212991 (68510.8 Da) was similar to that of Dy12.K of JB20 (68514.4 Da), and lower than Dy12 of CS (69151.2 Da). The result of LTQ-FT-MS based on 2-DE, the D1y of IT212991 was identified to be similar with Dy12 corresponding to the protein function as ‘Glutenin, high molecular weight subunit 12’. The D1y encoding the D1y of IT212991 was identified to consist of 652 amino acid sequences corresponding to 1962 bp according to DNA sequencing. The gene was identified to have a insertion and deletion (InDel) corresponding to 18 bp sequences ‘AACAGGACAAGGGCAACA’ compared to ordinary Dy12 gene. It was demonstrated that the D1y of IT212991 is the same as Dy12.K.     

小麦新品种(系)Glu-1位点等位基因变异研究

应用SDS-PAGE技术分析了40份小麦新品种(系)的高分子量麦谷蛋白亚基等位基因变异。在Glu-1位点共检测到10种变异类型,其中Glu-Al位点有3种类型：Null、1、26 ,Glu-B1位点有5种类型：7 8、7 9、14 15、7、17 18,Glu-D1位点有2种类型：2 12、5 10;Null(54．3％)、7 8(51．4％)和2 12(62．9％)分别是Glu-Al、Glu-B1和Glu-D1位点上的主要亚基变异类型。另外,在2份材料的Glu-B1和Glu-D1位点各检测到1个新的亚基,分别命名为1By8．1和1Dx5^ 。Glu-1位点的Nei‘s遗传变异指数平均为0,5648,Glu-B1的遗传多样性最高,Glu-D1最低。供试小麦材料Glu-1位点的HMW-GS组合共有17种类型,以(Null,7 8,2 12)组合为主要类型,占31．4％;有9种亚基组合类型分别只在1份材料中出现,占26.1％。结果表明,这些小麦新品种(系)存在着丰富的亚基组合类型。