Sixty-two DNA sequences for the coding regions of omega-secalin (-secalin) genes have been characterized from rye (Secale cereale L.), hexaploid and octoploid triticale (x Triticosecale Wittmack), and wheat (Triticum aestivum L.) 1BL/1RS translocation line. Only 19 out of the 62 omega-secalin gene sequences were full-length open reading frames (ORFs), which can be expressed into functional proteins. The other 43 DNA sequences were pseudogenes, as their ORFs were interrupted by one or a few stop codons or frameshift mutations. The 19 -secalin genes have a typical primary structure, which is different from wheat gliadins. There was no cysteine residue in -secalin proteins, and the potential celiac disease (CD) toxic epitope (PQQP) was identified to appear frequently in the repetitive domains. The -secalin genes from various cereal species shared high homology in their gene sequences. The omega-secalin gene family has involved fewer variations after the integration of the rye R chromosome or whole genome into the wheat or triticale genome. The higher Ka/Ks ratio (i.e. non-synonymous to synonymous substitutions per site) in omega-secalin pseudogenes than in -secalin ORFs indicate that the pseudogenes may be subject to a reduced selection pressure. Based on the conserved sequences of omega-secalin genes, it will be possible to manipulate the expression of this gene family in rye, triticale, or wheat 1BL/1RS translocation lines, to reduce its negative effects on grain quality.
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.