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 SDSPAGE. All accessions were conWrmed 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-Am1a and “valine-type” ETI encoded by allele Eti-Am1b, 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 mm2/mg of starch, and was about 1.5 times higher than that for common wheat. The results are discussed in relation to the identiWcation of factors that cause the extrasoft texture of einkorn kernels.
|Titolo:||Starch-bound 2S proteins and kernel texture in einkorn,Triticum monococcum ssp monococcum|
|Data di pubblicazione:||2009|
|Appare nelle tipologie:||1.1 Articolo in rivista|