High molecular weight (HMW-GS) and low molecular weight (LMW-GS) glutenin subunits play a significant role in bread making quality and extensibility, though they signify merely 10% and 40% of the entire seed storage proteins. For the estimation of bread quality on the basis of allelic difference in HMW-GS and LMW-GS at Glu-1 and 3 loci, wheat germplasm (77 genotypes) was collected from diverse agro-climatic regions of Pakistan and characterized by using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Thirty distinct allelic arrangements were identified with a sum of thirteen Glu-1 alleles. Maximum frequency of allele 1 was found in twenty-nine genotypes at Glu-A1 locus while high proportion of subunit pairs 13 + 16 and 2 + 12 was detected in 33 and 32 genotypes at Glu-B1 as well as Glu-D1 locus, respectively. Few rare alleles were also separated out. The quality scores ranged from 4–10, however highest quality score of ten was more recurrent (36.36%). A good quality score of 8 and 6 were found in 32.47% as well as 19.48% of genotypes individually. In LMW-GS, seventeen diverse combinations of alleles with aggregate of ten Glu-3 alleles were detected. Glu-A3c and Glu-B3d alleles were observed in 33 (42.85%) genotypes, encoding high sedimentation and protein contents. Hence, this will enable the breeders to utilize both glutenin subunits as biochemical indicator for selecting superior wheat genotypes possessing enhanced bread making quality.
Authors:N. Tsenov, D. Atanasova, I. Todorov, I. Ivanova, and I. Stoeva
, Novi Sad, Serbia, pp. 377–382.
Deng, Z.Y., Tian, J.C., Sun, G.X. 2005. Influence of high molecular weight gluteninsubunit substitution on rheological behavior and bread-baking quality of near-isogenic lines
Authors:B. Feng, Z.B. Xu, X. Wang, F. Jiang, G.J. Zhao, C. Xiang, and T. Wang
High molecular weight (HMW) glutenin subunits are important seed storage proteins in wheat and its related species. Novel HMWglutenin subunits in Aegilops tauschii accession of TA2484 were detected and characterized. SDS-PAGE analysis revealed the y-type subunit from TA2484 displayed similar electrophoretic mobility compared to that of 1Dy12 subunit. However, the electrophoretic mobility of x-type subunit was faster than that of 1Dx2 subunit. The primary structure of the two cloned subunits from TA2484 was similar to that of the x- and y-type subunits reported before. However, the 148 residues of the x-type subunit, which contained the sequence element GHCPTSLQQ, in the middle of the repetitive domain was quite different from other x-type subunits. Moreover, the 68 residues in this region were identical to those of the y-type subunits from the same accession. Consequently, 1Dx2.3*t (x-type subunit of TA2484) contains an extra cystenin residue located at the repetitive domain, which is novel compared to the x-type subunits reported so far. Phylogenetic analysis indicated that two subunits from accession TA2484 were in the x- and y-type subunit cluster, but bootstrapping value of 100% gave high support for the spilt between two subunits (1Dx2.3*t and 1Dy12.3*t) and their alleles, respectively. A hypothesis on the genetic mechanism generating this novel sequence of 1Dx2.3*t subunit is suggested.
A collection of 35 accessions of the tetraploid wild wheat Aegilops geniculata Roth (MM, UU) sampled in northern Algeria was evaluated for morphological and biochemical variability. Morphological and ecological analyses based on morphological traits and bioclimatic parameters, respectively, were assessed using principal component analysis (PCA). Accessions were differentiated by width characters, namely spike’s width, and a weak relationship between morphological traits and ecological parameters was found. Polymorphism of high molecular weight (HMW) glutenin subunits was carried on by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Among accessions analyzed, 27 alleles were identified at the two loci Glu-M1 and Glu-U1: resulting in twenty-nine patterns and a nomenclature was proposed. Two alleles at the Glu-U1 locus expressed a new subunit with a slightly slower mobility than subunit 8. These results provide new information regarding the genetic variability of HMW glutenin subunits, as well as their usefulness in cultivated wheat quality improvement.
Authors:J. Zhou, W. Liu, C. Han, H. Cao, Y. Xu, W. Zhang, and Y. Yan
Wheat glutenins containing high and low molecular weight glutenin subunits (HMW-GS and LMW-GS) are the major determinants of wheat gluten quality. In this study, the recently developed reversed-phase ultra-performance liquid chromatography (RP-UPLC) was used to study the synthesis and accumulation patterns of glutenins during grain development of four Chinese bread wheat cultivars with different gluten quality. Developing grains were collected based on thermal times from 150 °Cd to 750 °Cd at 100 °Cd intervals, and the content of glutenin subunits and their accumulation patterns were determined by RP-UPLC as well as sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that HMW-GS and LMW-GS synthesis were initiated currently at 250 °Cd and they displayed a gradually upregulated expression. All the HMW-GS can be detected at 250 °Cd, earlier than LMW-GS. Different glutenin subunits and genotypes showed clear accumulation diversity during grain development. Particularly, 1Dx5 + 1Dy10 in the cultivar Gaocheng 8901 and Zhongyou 9507 with superior dough properties were accumulated faster at early stages than 1Dx2 + 1Dy12 in Jingdong 8 and Zhengmai 9023 with poor dough quality, suggesting that faster accumulation rate of glutenin proteins at the early stages of grain development may contribute to the formation of superior gluten structure and dough quality.
Bellil I., Chekara-Bouziani M., Khelifi D. 2012. Genetic diversity of high and low molecular weight gluteninsubunits in Saharan bread and durum wheats from Algerian Oases. Czech J. of Genetics and Plant Breeding 48 :23