Identification and molecular characterisation of HMW glutenin subunit 1By16* in wild emmer

Abstract

In this study, a novel y-type high molecular weight glutenin subunit (HMW-GS) in wild emmer wheat Triticum turgidum L. var. dicoccoides (Körn.) accession KU1952 was identified by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), capillary electrophoresis (CE) and matrix-assisted laser desorption ionisation/time-of-flight/mass spectrometry (MALDI-TOF-MS). Its electrophoretic mobility and molecular weight were similar to those of 1By16 and was designated as 1By16*. The complete coding sequence of the 1By16* gene isolated by allelic-specific polymerase chain reaction (AS-PCR) consists of 2,157 bp, encoding 729 amino acid residues. The real presence and authenticity of the 1By16* gene in KU1952 were further confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), heterologous expression and Western blotting. The molecular structure as well as phylogenetic analysis revealed that 1By16* had 21 single-nucleotide polymorphism (SNP) variations and possessed greater similarity with superior quality subunits 1By15 and 1By16 of common wheat. Secondary structure prediction displayed higher α-helix and β-strand contents in the 1By16* subunit, which could form a superior gluten structure and, consequently, might have positive effects on dough quality. Our results suggest that 1By16* is expected to be a new potential gene for wheat quality improvement.