Length variation of i-type low-molecular-weight glutenin subunit genes in diploid wheats

Liu

Journal of Experimental Botany

et al. 2013

Low-molecular-weight glutenin subunits (LMW-GS), encoded by a complex multigene family, play an important role in the processing quality of wheat flour. Although members of this gene family have been identified in several wheat varieties, the allelic variation and composition of LMW-GS genes in common wheat are not well understood. In the present study, using the LMW-GS gene molecular marker system and the full-length gene cloning method, a comprehensive molecular analysis of LMW-GS genes was conducted in a representative population, the micro-core collections (MCC) of Chinese wheat germplasm. Generally, >15 LMW-GS genes were identified from individual MCC accessions, of which 4–6 were located at the Glu-A3 locus, 3–5 at the Glu-B3 locus, and eight at the Glu-D3 locus. LMW-GS genes at the Glu-A3 locus showed the highest allelic diversity, followed by the Glu-B3 genes, while the Glu-D3 genes were extremely conserved among MCC accessions. Expression and sequence analysis showed that 9–13 active LMW-GS genes were present in each accession. Sequence identity analysis showed that all i-type genes present at the Glu-A3 locus formed a single group, the s-type genes located at Glu-B3 and Glu-D3 loci comprised a unique group, while high-diversity m-type genes were classified into four groups and detected in all Glu-3 loci. These results contribute to the functional analysis of LMW-GS genes and facilitate improvement of bread-making quality by wheat molecular breeding programmes.

Section: Discussionmentioning

confidence: 99%

Novel insights into the composition, variation, organization, and expression of the low-molecular-weight glutenin subunit gene family in common wheat

Liu

Journal of Experimental Botany

et al. 2013

“…Abundant variability of storage proteins in T. urartu , was detected in gliadin proteins and HMW-GSs using electrophoretic procedures or nucleotide sequence analysis [ 29 , 30 ]. Several variants with repetitive domain length polymorphism were also observed in LMW-GS genes [ 31 ]. However, the detailed composition and genetic diversity of LMW-GS genes in T. urartu remain unknown.…”

Section: Introductionmentioning

confidence: 99%

Composition, variation, expression and evolution of low-molecular-weight glutenin subunit genes in Triticum urartu

Luo

et al. 2015

BMC Plant Biol

BackgroundWheat (AABBDD, 2n = 6x = 42) is a major dietary component for many populations across the world. Bread-making quality of wheat is mainly determined by glutenin subunits, but it remains challenging to elucidate the composition and variation of low-molecular-weight glutenin subunits (LMW-GS) genes, the major components for glutenin subunits in hexaploid wheat. This problem, however, can be greatly simplified by characterizing the LMW-GS genes in Triticum urartu, the A-genome donor of hexaploid wheat. In the present study, we exploited the high-throughput molecular marker system, gene cloning, proteomic methods and molecular evolutionary genetic analysis to reveal the composition, variation, expression and evolution of LMW-GS genes in a T. urartu population from the Fertile Crescent region.ResultsEight LMW-GS genes, including four m-type, one s-type and three i-type, were characterized in the T. urartu population. Six or seven genes, the highest number at the Glu-A3 locus, were detected in each accession. Three i-type genes, each containing more than six allelic variants, were tightly linked because of their co-segregation in every accession. Only 2-3 allelic variants were detected for each m- and s-type gene. The m-type gene, TuA3-385, for which homologs were previously characterized only at Glu-D3 locus in common wheat and Aegilops tauschii, was detected at Glu-A3 locus in T. urartu. TuA3-460 was the first s-type gene identified at Glu-A3 locus. Proteomic analysis showed 1-4 genes, mainly i-type, expressed in individual accessions. About 62% accessions had three active i-type genes, rather than one or two in common wheat. Southeastern Turkey might be the center of origin and diversity for T. urartu due to its abundance of LMW-GS genes/genotypes. Phylogenetic reconstruction demonstrated that the characterized T. urartu might be the direct donor of the Glu-A3 locus in common wheat varieties.ConclusionsCompared with the Glu-A3 locus in common wheat, a large number of highly diverse LMW-GS genes and active genes were characterized in T. urartu, demonstrating that this progenitor might provide valuable genetic resources for LMW-GS genes to improve the quality of common wheat. The phylogenetic analysis provided molecular evidence and confirmed that T. urartu was the A-genome donor of hexaploid wheat.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0322-3) contains supplementary material, which is available to authorized users.

Wheat Research and Utilization

“…The loci of HMW-GS (Glu-A1, Glu-B1 and Glu-D1) and LMW-GS (Glu-A3, Glu-B3 and Glu-D3) subunits are located on the long and short arms, respectively [69]. In one of the largest studies on the effect of glutenins on wheat quality, it was reported that Glu-B1, Glu-D1, and Glu-B3 loci have the greatest effect on glutenin variations compared to other loci [8,[70][71][72]. In addition to GPC, several MTAs that have a significant relationship with baking quality (mixograph mixing and bake mixing times) can be used in MAS due to their tight linkage with glutenin and gliadin loci [61].…”

Section: Marker-assisted Selection (Mas) and Its Applications In Impr...mentioning

confidence: 99%

Application of Marker-Assisted Selection in Wheat Quality Breeding Program

Hassaneian Khoshro,

Abdi

2024

Bread wheat is grown worldwide for the nutritional values of the seed storage proteins representing an imperative source of food and energy. The major seed storage proteins are glutenins and gliadins. Glutenins, mainly related to protein quality in wheat, are divided into two groups, high-molecular-weight glutenin subunits (HMW-GS) and low-molecular-weight glutenin subunits (LMW-GS). HMW-GS are the key factors in bread-baking process as the major determinants of dough elasticity, and LMW-GS play a major role in determining dough resistance and extensibility. Marker-assisted selection (MAS) is believed to revolutionize breeding practices through improved efficiency and precision of selection. In recent years, advancements in molecular genetics resulted in the identification of DNA tags associated with specific alleles of HMW and LMW glutenin subunits and loci involved in bread-making quality, that is, Glu-1 and Glu-3. Selection for favorable glutenin alleles significantly improved dough extensibility and dough resistance.