The γ-gliadin-like γ-prolamin genes in the tribe Triticeae

J Genet. 2014 Apr;93(1):35-41. doi: 10.1007/s12041-014-0330-y.

Abstract

The γ-prolamins are important components of seed storage proteins in wheat and other Triticeae species. Here, the γ-prolamin genes from the diploid Triticeae species were systemically characterized. Most of the γ-prolamins (except 75 K γ-secalins) characterized were defined as γ-gliadin-like γ-prolamins, since they shared same characteristic model structure with γ-gliadins. Over one-third of these putatively functional γ-prolamin peptides contained different number of cysteine residues as compared to the eight residues present in γ-gliadins. Sequence polymorphism and linkage disequilibrium analyses showed the conservation of γ-prolamin genes in Triticeae species under evolutionary selection. Phylogenetic analyses indicated that these γ-prolamin genes can not be clearly separated according to their genomic origins, reflecting the conservation of γ-gliadinlike γ-prolamin genes after the divergence of Triticeae species. A screening of coeliac disease (CD) toxic epitopes shows that the γ-prolamins from some other genomes contain much fewer epitopes than those from the A, S (B) and D genomes of wheat. These findings contribute to better understanding of γ-prolamin family in Triticeae and build a ground for breeding less CD-toxic wheat cultivars.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cysteine / chemistry
  • Edible Grain / classification
  • Edible Grain / genetics*
  • Epitopes / chemistry
  • Genetic Variation
  • Gliadin / chemistry
  • Gliadin / genetics*
  • Molecular Sequence Data
  • Open Reading Frames
  • Phylogeny
  • Prolamins / chemistry
  • Prolamins / genetics*
  • Protein Interaction Domains and Motifs
  • Sequence Alignment

Substances

  • Epitopes
  • Prolamins
  • Gliadin
  • Cysteine