优质小麦品种Glu-A3位点LMW-GS基因的克隆及分子特征
优质小麦品种Glu-A3位点LMW-GS基因的克隆及分子特征
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DOI：
10.3864/j.issn.0578-1752.2010.05.001
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发表时间：
2010-03
期刊：
影响因子：
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通讯作者：
魏燕燕
中科院分区：
文献类型：
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作者：
韩冉;赵惠贤;马猛;魏燕燕
【目的】揭示不同小麦品种Glu-A3位点LMW-GS基因的分子特征，寻找具有潜在品质改良价值的候选基因。【方法】以我国小麦品种小偃6号、陕优225、澳大利亚面包小麦品种Suneca、Cook和中国春为材料，利用特异引物，通过PCR技术克隆Glu-A3位点的LMW-GS基因，并对其进行分析。【结果】在Glu-A3位点克隆到5个LMW-GS基因，分别命名为CookGlu-A3（登录号EU 871816）、XYGlu-A3（FJ 876820）、SYG 1u-A3（FJ 876819）、SunecaGlu-A3（FJ 876822）、CSGIu-A3（FJ 876821）。它们都含有完整的编码区，启动子序列197 bp，终止密码子后下游序列51 bp。5个基因之间的差异主要表现为存在SNPs和插入/缺失。这5个基因推导的蛋白质均属于LMW-i型。CookGlu-A3蛋白的C端含有7个半胱氨酸残基，缺失第7个保守的Cys残基，C端有一个38个氨基酸的片段。根据编码序列的相似性，将51个已知的LMW：GS基因分为3类，每一类分别对应于一个特定的位点Glu-A3、Glu-B3和Glu-D3。【结论】CookGlu-A3编码的是一个含7个半胱氨酸残基的LMW-i型谷蛋白亚基，可能是一个新的LMW-GS基因，不同染色体位置的LMW-GS基因编码序列各有特点。Glu-A3位点的LMW-GS基因编码序列与Glu-B3或Glu-D3位点的LMW-GS基因编码序列同源性较低。
[Objective] The objective of this study was to reveal the molecular characteristics of LMW-GS genes at Glu-A3 locus in different wheat cultivars, and to find candidate genes with potential value in wheat quality improvement. [Method] Chinese wheat cultivars Xiaoyan 6, Shaanyou 225, and Australian bread wheat cultivars Suneca and Cook, as well as Chinese Spring were selected as materials to clone and characterize LMW-GS genes at Glu-A3 locus with the specific primer by PCR in this investigation. [Result] Five LMW-GSgenes at Glu-A3 locus were cloned, named as CookGlu-A3 (accession number EU871816), XYGIu-A3 (FJ876820), SYG1u-A3 (FJ876819), SunecaGlu-A3 (FJ876822), CSGIu-A3 (FJ876821). All of them contained the entire coding regions, 197 bp of promoter sequences and 51 bp downstream sequences after stop codons. The differences among the five genes were that there existed some SNPs and insertions/deletions. All the deduced proteins of the five genes belong to LMW-i type. Notablely, the deduced protein of CookGlu-A3 contained 7 cysteine residues, with a 38 aa fragment in the C-terminal domain including the 7th conserved Cys residue missing. On the basis of the similarity of coding sequence, 51 known LMW:GS genes were classified into three groups, and each group was corresponding to a specific locus Glu-A3, Glu-B3 or Glu-D3, respectively. [Conclusion] CookGlu-A3 encoded a LMW-i type glutenin subunit with 7 cysteine residues, and it may be a novel LMW-GS gene.All LMW-GS genes at different chromosomal locations had their own specific characteristics in their coding Sequences. The coding sequences of thd LMW-GS genes at locus Glu-A3 had less identity with those at locus Glu-B3 or Glu-D3.