title: Novel DNA variations to characterize low molecular weight glutenin Glu-D3 genes and develop STS markers in common wheat.
abstract: Low-molecular-weight glutenin subunits (LMW-GS) play an important role in bread and noodle processing quality by influencing the viscoelasticity and extensibility of dough. The objectives of this study were to characterize Glu-D3 subunit coding genes and to develop molecular markers for identifying Glu-D3 gene haplotypes. Gene specific primer sets were designed to amplify eight wheat cultivars containing Glu-D3a, b, c, d and e alleles, defined traditionally by protein electrophoretic mobility. Three novel Glu-D3 DNA sequences, designated as GluD3-4, GluD3-5 and GluD3-6, were amplified from the eight wheat cultivars. GluD3-4 showed three allelic variants or haplotypes at the DNA level in the eight cultivars, which were designated as GluD3-41, GluD3-42 and GluD3-43. Compared with GluD3-42, a single nucleotide polymorphism (SNP) was detected for GluD3-43 in the coding region, resulting in a pseudo-gene with a nonsense mutation at the 119th position of deduced peptide, and a 3-bp insertion was found in the coding region of GluD3-41, leading to a glutamine insertion at the 249th position of its deduced protein. The coding regions for GluD3-5 and GluD3-6 showed no allelic variation in the eight cultivars tested, indicating that they were relatively conservative in common wheat. Based on the 12 allelic variants of three Glu-D3 genes identified in this study and three detected previously, seven STS markers were established to amplify the corresponding gene sequences in wheat cultivars containing five Glu-D3 alleles (a, b, c, d and e). The seven primer sets M2F12/M2R12, M2F2/M2R2, M2F3/M2R3, M3F1/M3R1, M3F2/M3R2, M4F1/M4R1 and M4F3/M4R3 were specific to the allelic variants GluD3-21/22, GluD3-22, GluD3-23, GluD3-31, GluD3-32, GluD3-41 and GluD3-43, respectively, which were validated by amplifying 20 Chinese wheat cultivars containing alleles a, b, c and f based on protein electrophoretic mobility. These markers will be useful to identify the Glu-D3 gene haplotypes in wheat breeding programs.
authors.affiliation: Institute of Crop Science, National Wheat Improvement Center, The National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences (CAAS), Zhongguancun South Street 12, Beijing 100081, China.
authors.forename: X L
authors.initials: XL
authors.lastname: Zhao
authors.forename: X C
authors.initials: XC
authors.lastname: Xia
authors.forename: Z H
authors.initials: ZH
authors.lastname: He
authors.forename: Z S
authors.initials: ZS
authors.lastname: Lei
authors.forename: R
authors.initials: R
authors.lastname: Appels
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: Q X
authors.initials: QX
authors.lastname: Sun
authors.forename: W
authors.initials: W
authors.lastname: Ma
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D018744:DNA, Plant / Q000235:genetics*; D017343:Genes, Plant; D005819:Genetic Markers; D005983:Glutens / Q000737:chemistry / Q000235:genetics*; D006239:Haplotypes; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D017385:Sequence Homology; D014908:Triticum / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers; D005983:Glutens; C037302:glutenin