Molecular Characterization Of A Novel Class Of α-Gliadin Gene

Gliadins play an important role in the nutritional quality of flour, taking 40-50% parts in seed storage protein. According to their different mobilities based on acid polyacrylamide gel electrophoresis (A-PAGE), gliadins can be divided into four types, i.e. α, β,γ and ω, and they cover 25,30,30 and 15% in gliadins respectively. Later research indicated that a-gliadin and β-gliadin were very similar in structure, and they were named as a-gliadin. a-Gliadin gene family has abundant genetic diversity. This study characterized a novel class of a-gliadin. genes. The major results are listed as follows:1. A pair of. primer (AlphaF+AlphaR) was designed to amplify the full open reading frame of a-gliadin genes, on the basis of a-gliadin gene sequences deposited in NCB1 database. A novel class of a-gliadin genes were obtained from Psathyrostachys and Leymus, while no novel gene was identified in Triticum aestivum yet.2. The insert domain of the novel a-gliadins was composed of repetitive sequences. The repetitive sequences was similar to N-terminal part of the unique Ⅱ of novel a-gliadins.3. The known toxic peptides for celiac disease was not found in any one of the novel a-gliadins, suggesting that the novel a-gliadin genes are hopeful gene resource for wheat breeding.4. Molecular marker was successfully developed for the novel a-gliadins, based on the insert domain. Application of molecular marker suggested the presence of novel a-gliadin genes in common wheat, which was verified by sequencing.