Special HMW-GSs and their genes of Triticum turgidum subsp. dicoccoides accession D141 and the potential utilization in common wheat

Abstract

High molecular weight glutenin subunits (HMW-GSs) are the critical components of wheat seed storage proteins. They play a crucial role in determining dough viscoelastic properties and end-use quality of wheat flour. To investigate the potential utilization of the special HMW-GSs from wild emmer wheat (2n = 4x = 28, AABB) accession D141 in common wheat (2n = 6x = 42, AABBDD), continued to our previous report of the 1Ay and its coding sequence, the other three HMW-GSs, 1Ax, 1Bx13.1 and 1By16.1, and their coding genes were isolated, characterized and transferred from D141. The 1Ax gene was silent because of containing a premature stop codon TGA at position 835–837. The ORFs of 1Bx13.1 and 1By16.1 were 2373 and 2157 bp in length, and encoded 789 and 717 amino acid residues, respectively. Compared with the other 20 Glu-1Bx alleles in GenBank, seven SNPs and one 18-bp deletion were detected in 1Bx13.1. Compared with the other 10 Glu-1By alleles in GenBank, nine SNPs were observed in 1By16.1. The mobility of 1Bx13.1 and 1By16.1 on the SDS-PAGE gel was most similar to that of 1Bx13 and 1By16 from common wheat (T. aestivum, 2n = 6x = 42, AABBDD) cv. ‘Jimai 20′, respectively. Protein secondary structure prediction showed that the combination of 1Bx13.1 + 1By16.1 possessed more α-helixes with more amino acid residues than that of 1Bx13 + 1By16. It suggested that 1Bx13.1 + 1By16.1 from wild emmer accession D141 might have more positive effects on bread-making quality than the superior subunit combination 1Bx13 + 1By16. The HMW-GS composition analysis of F1 and F2 between common wheat for female and wild emmer accession D141 for male, indicated that the special HMW-GSs from wild emmer accession D141 could be easily introduced into common wheat (2n = 42) by general inter-species hybridization.