栽培一粒小麦α-醇溶蛋白新基因的克隆与序列分析  

Cloning and Sequence Analysis of New α-Gliadin Genes from Triticum monococcum

作　　者：李玉阁[1] 邢冉冉[1] 李锁平[1] 

机构地区：[1]河南大学生命科学学院,河南开封475004

出　　处：《麦类作物学报》2012年第3期387-392,共6页Journal of Triticeae Crops

基　　金：国家自然科学基金项目(30971774);"十二五"农村领域国家科技计划课题(2011BAD07B00);河南省教育厅自然科学基金项目(2008A180006)

摘　　要：α-醇溶蛋白是人们生活中消费最多的蛋白,由于含有引起乳糜泻(CD)的主要毒性肽成分,也是引起CD的最活跃的蛋白。为了解一粒小麦在小麦品质育种中的潜力,利用1对α-醇溶蛋白的特异引物,采用基因组PCR法从栽培一粒小麦中克隆α-醇溶蛋白新基因,共获得片段大小为856～882bp的4个基因序列,分别命名为AA-6、AA-8、AA-9和AA-21(GenBank登录号为JN831382～JN831385)。其中,AA-8、AA-9和AA-21均在102位因C→T替换而导致TAG终止子出现成为假基因;AA-6由882个核苷酸构成,可编码293个氨基酸,与已知基因的最高同源性为99%,推断氨基酸序列具有α-醇溶蛋白的典型结构,是α-醇溶蛋白家族的新成员。AA-6的CD毒性肽分析表明,除不含A基因组所没有的glia-α和glia-α2毒性肽外,其他已知的7种毒性肽均有分布。AA-6和86个来源于小麦及其祖先供体种的α-醇溶蛋白的同源性分析表明,α-醇溶蛋白基因存在基因组来源的差异性,其中,A、D基因组来源的α-醇溶蛋白基因的相似性较高。The α-gliadins were typically the most consumed storage proteins in human life,however,owing to the main toxic components they contained causing celiac disease（CD）,the α-gliadins were also the most active proteins in triggering CD.So the objective of this study was to estimate the potential value in wheat quality breeding of the cloned α-gliadin sequences from the genomic DNA and to analyze the CD epitopes among them.One new α-gliadin gene with full-ORF（named as AA-6,GenBank accession No.JN831382） and three pseudogenes（named as AA-8,AA-9,AA-21,GenBank accession No.JN831383,JN831384 and JN831385,respectively） were cloned and sequenced.The three pseudogenes resulted from C to T base transitions,which leading to the alternative of a CAG codon for glutamine into a TAG stop codon at the position of 102 bp.Analysis on the deduced amino acid sequences of AA-6 revealed that AA-6 was characterized with the typical structure of α-gliadins,with the highest homology of 99%.Analysis on its CD epitops demonstrated that seven toxic peptides of the nine known epitops were present in AA-6 except for the absence of Glia-α2 and Glia-α in the A genome.Phylogenetic analysis among AA-6 and 86 genes from common wheat and its ancestral species showed that a clear cluster can be observed according to the origin of their genome.The homology of A genome and D genome was more close than that of B genome.

关 键 词：栽培一粒小麦 α-醇溶蛋白 基因克隆 乳糜泻 系统进化 

分 类 号：S512.1[农业科学—作物学] S330