Cloning and characterization of special HMW glutenin subunit genes from Aegilops longissima L. and their potential for wheat quality improvement
Identification and cloning of new glutenin genes from wheat-related species can provide candidate gene resources for quality improvement of wheat. In this study, ten special high-molecular-weight glutenin subunits (HMW-GS), including five x-type (1Sl2x, 1Sl16x, 1Sl17x, 1Sl23x, and 1Sl25x) and five y-type (1Sl2y, 1Sl6y1, 1Sl16y, 1Sl17y, and 1Sl23y) from Aegilops longissima L. (SlSl, 2n = 2x = 14) were identified, and their complete encoding genes were cloned by allelic-specific polymerase chain reaction (AS-PCR). The deduced amino acid (aa) residues of the x-type subunit genes ranged from 821 aa (2469 bp) to 941 aa (2829 bp), while those of the y-type subunit genes varied from 749 aa (2250 bp) to 771 aa (2361 bp). These special HMW-GS had a longer central repetitive domain with more glutamine repeats and glutamine residues compared to the previously characterized HMW-GS in common wheat, which provided a structural basis for superior gluten quality formation. The authenticity of the four cloned genes were verified by matrix-assisted laser desorption ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF–MS). Abundant single-nucleotide polymorphism (SNP) and insertion/deletion (InDel) variations among these genes were identified, which would benefit for developing specific molecular markers used for wheat gluten quality improvement. Phylogenetic analysis revealed that the 1Sl-encoded HMW-GS had close relationships with those from bread wheat, which were divergent from Triticum species at 2.10–10.00 million years ago. Our results indicate that the 1Sl genome contains superior candidate glutenin genes that have potential application values for the improvement of wheat bread making quality.
KeywordsAegilops longissima L. HMW-GS AS-PCR MALDI-TOF/TOF–MS Phylogenetics Gluten quality
This research was financially supported by Grants from National Key R & D Program of China (2016YFD0100502) and the National Natural Science Foundation of China (31771773).
- Bekes F, Gras PW, Gupta RB (1995) The effects of purified cereal polypeptides on the mixing properties of dough. In: Williams YA, Wrigley CW (eds) Capturing the benefits of research for consumers. R. Aust. Chem. Inst, Cereal Chem Div, pp 92–98Google Scholar
- Neelam K, Rawat N, Tiwari VK, Ghandhi N, Arun PC, Kumar S, Tripathi SK, Randhawa GS, Prasad R, Dhaliwal HS (2013) Development and molecular characterization of wheat-Aegilops longissima derivatives with high grain micronutrients. Aust J Crop Sci 7:508–514Google Scholar
- Payne PI, Lawrence GJ (1983) Catalogue of alleles for the complex gene loci, Glu-A1, Glu-B1 and Glu-D1 which code for high-molecular-weight subunits of glutenin in hexaploid wheat. Cereal Res Commun 11:29–35Google Scholar