Genetic aspects of wheat gliadin proteins

Abstract

Inheritance of gliadin components unique to three different varieties of common wheat (Triticum aestivum L.) was studied in F1 and F2 seeds of intervarietal crosses using protein patterns obtained by polyacrylamide gel electrophoresis in aluminum lactate buffer (pH 3.2). The patterns of F1 seeds of the crosses Cheyenne X Justin and INIA 66R X Justin evidenced all the bands present in the patterns of the parents; band intensities reflected gene dosage levels dependent on whether the contributing parent was maternal or paternal in accordance with the triploid nature of endosperm tissue. Most of the gliadin components examined segregated in accordance with control by a single dominant gene, but in two instances single bands in the one-dimensional electrophoretic patterns segregated in the F2 as expected if controlled by two genes. A method of two-dimensional electrophoresis was developed that resolved these apparently single bands into two components each, which could segregate independently. Linkage analysis provided evidence of codominant alleles and closely linked genes coding for gliadin protein components in both coupling and repulsion situations. The gliadin protein components seem to be coded for by clusters of genes located on chromosomes of homoeologous groups 1 and 6 in hexaploid wheats.

Nucleic acid (cDNA) and amino acid sequences of alpha-type gliadins from wheat (Triticum aestivum).

“…Peptide mixtures were subjected to gel permeation chromatography on various Bio-Gel columns in 0.01 M NH4OAc/4 M urea, pH 5.0, followed by ion-exchange chromatography on carboxymethylcellulose CM-52 (Whatman) at pH 4.5 in 4 M urea (freshly deionized) with ammonium acetate gradients in the range 0.0 to 2.0 M. Peptide purity was determined by electrophoresis (8,25) or by sequencing the preparation. Amino acid analysis was performed on a Durrum D-500 analyzer (Dionex, Sunnyvale, CA).…”

“…They are important dietary proteins and determinants of dough and bread-baking quality but are limited in nutritional quality by low levels of lysine (1,2). In addition, gliadins, or peptides derived from them during digestion, initiate damage to the absorptive epithelium of the small intestine to produce the consequent symptoms of celiac disease in susceptible individuals (3, 4).Gliadins, which are synthesized on membrane-bound ribosomes in the endosperm cells during grain development (5,6), are separated into 35-50 components by two-dimensional electrophoresis (7,8); all components are rich in glutamine (30-50 mol %) and proline (15-30 mol %). On the basis of NH2-terminal amino acid sequences, gliadins may be grouped into three subfamilies (9, 10), a-type, -type, and wtype.…”

“…Gliadins, which are synthesized on membrane-bound ribosomes in the endosperm cells during grain development (5,6), are separated into 35-50 components by two-dimensional electrophoresis (7,8); all components are rich in glutamine (30-50 mol %) and proline (15-30 mol %). On the basis of NH2-terminal amino acid sequences, gliadins may be grouped into three subfamilies (9,10), a-type, -type, and wtype.…”

Linkage relationships between genes controlling seed proteins in French bean

“…Studies of the seed storage proteins of many plants have suggested that the numerous storage protein subunits, distinguishable by molecular weight and isoelectric point, are the products of different but evolutionarily related genes clustered at a few genomic sites (Wrigley and Shepherd 1973;Mecham et al 1978). This hypothesis is supported by the considerable aminoacidsequence homology which has been shown for the gliadins of wheat (Triticum aestivum L.) (Bietz et al 1977) and for the zeins of maize (Zea mays L.) (Bietz et al 1979).…”

Gene-dosage compensation of endosperm proteins in hexaploid wheat Triticum aestivum

“…The high molecular weight ("HMW") glutenins and gliadins of common wheat are encoded by multigenic families located on the long and short arms, respectively, of chromosomes of group 1 (11)(12)(13). These genes provide a most suitable system for studying gene-dosage compensation.…”