Expression Profile of Two Storage-Protein Gene Families in Hexaploid Wheat Revealed by Large-Scale Analysis of Expressed Sequence Tags

• Published in: Plant physiology (Bethesda) 2005-12, Vol.139 (4), p.1870-1880
• Main Authors: Kawaura, Kanako, Mochida, Keiichi, Ogihara, Yasunari
• Format: Article
• Language: English
• Subjects: Base Sequence; Biological and medical sciences; Chromosome Mapping; Chromosomes; Chromosomes, Plant - genetics; DNA; DNA, Plant - genetics; Expressed Sequence Tags; Fundamental and applied biological sciences. Psychology; Gene Expression Profiling; gene expression regulation; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Genes; Genes, Plant; Genes. Genome; Genetic loci; genetic polymorphism; genetic variation; Genetics, Genomics, and Molecular Evolution; Genomes; Genomics; gliadin; Gliadin - genetics; Glutens - genetics; Hexaploidy; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Multigene Family; nucleotide sequences; Phylogeny; plant genetics; plant physiology; plant proteins; Plant Proteins - genetics; Plants; Polymorphism, Single Nucleotide; Polyploidy; seed development; seed maturation; Seeds - growth & development; storage proteins; Triticum - genetics; Triticum - growth & development; Triticum aestivum; Wheat
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.105.070722

To discern expression patterns of individual storage-protein genes in hexaploid wheat (Triticum aestivum cv Chinese Spring), we analyzed comprehensive expressed sequence tags (ESTs) of common wheat using a bioinformatics technique. The gene families for [alpha]/[beta]-gliadins and low molecular-weight glutenin subunit were selected from the EST database. The alignment of these genes enabled us to trace the single nucleotide polymorphism sites among both genes. The combinations of single nucleotide polymorphisms allowed us to assign haplotypes into their homoeologous chromosomes by allele-specific PCR. Phylogenetic analysis of these genes showed that both storage-protein gene families rapidly diverged after differentiation of the three genomes (A, B, and D). Expression patterns of these genes were estimated based on the frequencies of ESTs. The storage-protein genes were expressed only during seed development stages. The [alpha]/[beta]-gliadin genes exhibited two distinct expression patterns during the course of seed maturation: early expression and late expression. Although the early expression genes among the [alpha]/[beta]-gliadin and low molecular-weight glutenin subunit genes showed similar expression patterns, and both genes from the D genome were preferentially expressed rather than those from the A or B genome, substantial expression of two early expression genes from the A genome was observed. The phylogenetic relationships of the genes and their expression patterns were not correlated. These lines of evidence suggest that expression of the two storage-protein genes is independently regulated, and that the [alpha]/[beta]-gliadin genes possess novel regulation systems in addition to the prolamin box.