Hu Jinxin, Wang Jian, Deng Xiong, Yan Yueming
1College of Life Science, Capital Normal University, Beijing, Xisanhuan Beilu 105, Beijing, 100048 China.
2Hubei Collaborative Innovation Center for Grain Industry (HCICGI), Yangtze University, Jingzhou, 434025 China.
3 Biotech. 2019 Jul;9(7):267. doi: 10.1007/s13205-019-1803-8. Epub 2019 Jun 14.
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 (1S2x, 1S16x, 1S17x, 1S23x, and 1S25x) and five y-type (1S2y, 1S6y, 1S16y, 1S17y, and 1S23y) from L. (SS, 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 1S-encoded HMW-GS had close relationships with those from bread wheat, which were divergent from species at 2.10-10.00 million years ago. Our results indicate that the 1S genome contains superior candidate glutenin genes that have potential application values for the improvement of wheat bread making quality.
从小麦近缘物种中鉴定和克隆新的麦谷蛋白基因可为小麦品质改良提供候选基因资源。本研究从圆锥小麦（SS，2n = 2x = 14）中鉴定出10个特殊的高分子量麦谷蛋白亚基（HMW-GS），包括5个x型亚基（1S2x、1S16x、1S17x、1S23x和1S25x）和5个y型亚基（1S2y、1S6y、1S16y、1S17y和1S23y），并通过等位基因特异性聚合酶链反应（AS-PCR）克隆了它们的完整编码基因。x型亚基基因推导的氨基酸（aa）残基范围为821个aa（2469 bp）至941个aa（2829 bp），而y型亚基基因的氨基酸残基范围为749个aa（2250 bp）至771个aa（2361 bp）。与先前鉴定的普通小麦HMW-GS相比，这些特殊的HMW-GS具有更长的中央重复结构域，谷氨酰胺重复序列和谷氨酰胺残基更多，这为优异面筋品质的形成提供了结构基础。通过基质辅助激光解吸电离飞行时间/飞行时间质谱（MALDI-TOF/TOF-MS）验证了4个克隆基因的真实性。在这些基因中鉴定出了丰富的单核苷酸多态性（SNP）和插入/缺失（InDel）变异，这将有助于开发用于小麦面筋品质改良的特异性分子标记。系统发育分析表明，1S基因组编码的HMW-GS与面包小麦的HMW-GS关系密切，它们在210万至1000万年前与二穗短柄草属物种分化。我们的结果表明，1S基因组包含优异的候选麦谷蛋白基因，对改善小麦面包制作品质具有潜在应用价值。
