title: Starch-bound 2S proteins and kernel texture in einkorn, Triticum monococcum ssp monococcum.
abstract: The starch granule proteins from 113 einkorn wheat (Triticum monococcum ssp monococcum) accessions were analyzed by acidic, polyacrylamide gel electrophoresis (A-PAGE), and two-dimensional A-PAGE x SDS-PAGE. All accessions were confirmed to contain equal amounts of two polypeptide chains corresponding to puroindoline B (Pin-B), as well as a prominent component plus a faint band corresponding to puroindoline A (Pin-A). When compared with soft-textured common wheat, "monococcum" accessions showed an increase of 3.2- and 2.7-fold in Pin-A and Pin-B levels on the starch granules, respectively. In addition, all accessions contained a novel component of the 2S super-family of seed proteins named Einkorn Trypsin Inhibitor (ETI), which was found to be encoded as a pre-protein 148 residues long. Wild-type ETI encoded by allele Eti-A(m) 1a and "valine-type" ETI encoded by allele Eti-A(m) 1b, which occurred in 107 and six einkorn accessions, respectively, were found to accumulate on starch granules as a mature protein of 121 amino acids with a hydrophobic central domain. The einkorn accessions exhibited an average SKCS index as low as -2.05 +/- 11.4, which is typical of extra-soft kernels. The total surface area of starch granules in "monococcum" wheat, as determined by visual assessments in counting chambers, was estimated at 764 mm(2)/mg of starch, and was about 1.5 times higher than that for common wheat. The results are discussed in relation to the identification of factors that cause the extra-soft texture of einkorn kernels.
authors: CRA- QCE, Unit for Cereal Quality, 00191 Rome, Italy.
authors: Federica
authors: F
authors: Taddei
authors: Laura
authors: L
authors: Gazza
authors: Salvatore
authors: S
authors: Conti
authors: Vera
authors: V
authors: Muccilli
authors: Salvatore
authors: S
authors: Foti
authors: Norberto Edgar
authors: NE
authors: Pogna
mesh_terms: D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D013213:Starch / Q000235:genetics / Q000378:metabolism*; D014908:Triticum / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D013213:Starch