title: Novel LMW glutenin subunit genes from wild emmer wheat (Triticum turgidum ssp. dicoccoides) in relation to Glu-3 evolution.
abstract: Four low-molecular-weight-isoleucine (LMW-i)-type and one novel chimeric (between LMW-i and LMW-methionine (m) types) low-molecular-weight glutenin subunit (LMW-GS) genes were characterized from wild emmer wheat (Triticum dicoccoides), designated as emmer-1 to emmer-5. All five LMW-GS genes possessed the same primary structure shared by other published LMW-GSs. The three genes emmer-1, emmer-3, and emmer-5 are similar, with the exception that emmer-3 and emmer-5 lost a few repeat motifs compared to emmer-1. Gene duplication and insertions/deletions of repeat motifs mediated through unequal crossing over may be responsible for the generation of these three Glu-3 alleles. Although the first residue of mature peptide of emmer-4 is isoleucine, it is not typical LMW-i-type LMW-GS. Phylogenetic analysis indicated that emmer-4 is located in the LMW-m subgroup, suggesting a closer relationship with LMW-m-type gene Y14104 of T. durum. Sequence alignment indicated that the emmer-4 is likely a chimeric gene generated by illegitimate recombination between LMW-i and LMW-m type. Unequal crossing over and illegitimate recombination are effective mechanisms for enriching both copy numbers and variations of LMW-GSs.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, People's Republic of China.
authors.forename: Lumin
authors.initials: L
authors.lastname: Qin
authors.forename: Yu
authors.initials: Y
authors.lastname: Liang
authors.forename: Daozheng
authors.initials: D
authors.lastname: Yang
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.forename: Guangmin
authors.initials: G
authors.lastname: Xia
authors.forename: Shuwei
authors.initials: S
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D019143:Evolution, Molecular; D017343:Genes, Plant; D005983:Glutens / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D055315:Prolamins / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D014908:Triticum / Q000235:genetics*
chemical_list: D055315:Prolamins; D005983:Glutens; C037302:glutenin