Cloning and molecular characterization of TaAGO1, a member of argonaute gene family in wheat ( Triticum aestivum L.)
Cloning and molecular characterization of TaAGO1, a member of argonaute gene family in wheat ( Triticum aestivum L.)
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DOI：
10.5897/ajb11.1765
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发表时间：
2011-10
影响因子：
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通讯作者：
Tianlei Liu;Jin-cai Li;Juntao Gu;Wenjing Lu;Chengjin Guo;Ruijuan Li;X. Kai
中科院分区：
文献类型：
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作者：
Tianlei Liu;Jin-cai Li;Juntao Gu;Wenjing Lu;Chengjin Guo;Ruijuan Li;X. Kai
Argonaute（AGO）蛋白通过与成熟microRNA形成复合物在RNA沉默过程中发挥重要作用。在这项研究中，小麦AGO基因被称为TaAGO 1，它与拟南芥中的AtAGO 1和水稻中的OsAGO 1具有高度的相似性。TaAGO 1基因cDNA全长3747 bp，编码1099个氨基酸，分子量为122 kD，等电点为9.52。亚细胞预测分析表明，TaAGO 1是在内质网（ER）分选后靶向细胞质的。与AtAGO 1和OsAGO 1相似，TaAGO 1含有AGO中的两个保守结构域PIWI和DDH。系统发育分析表明，TaAGO 1可能来源于不同的祖先，在不同的植物物种中具有同源性。TaAGO 1基因的转录水平受缺磷胁迫、脱水胁迫和外源脱落酸（阿坝）处理的影响，表明该基因也参与了上述信号转导过程。Southern杂交分析表明，六倍体小麦的基因组AA、SS和DD均含有两个TaAGO 1拷贝。TaAGO 1基因在小麦中的表达下调导致小麦幼苗表型发生明显改变，表现出多种异常生长特征。综合本研究的结果，TaAGO 1在小麦中作为拷贝的子集存在，并通过调节TaAGO 1-MiRNA复合物的形成在沉默适当的靶基因方面发挥关键作用。关键词：小麦，argonaute（AGO）基因1，克隆，分子鉴定，反义表达。
Argonaute (AGO) proteins play important roles in RNA silencing processes through formation of complexes with the mature microRNAs. In this study, a wheat AGO gene referred to TaAGO1, which shares high similarities to AtAGO1 in Arabidopsis and OsAGO1 in rice, was characterized. As a cDNA full length of 3747 bp, TaAGO1 encodes a 1099-aa polypeptide with a molecular weight of 122 kD and an isoelectric point (pI) of 9.52. Subcellular prediction analysis suggests that TaAGO1 is to target onto the cytoplasm after endoplasmic reticulum (ER) sorted. Similar to AtAGO1 and OsAGO1, TaAGO1 contains PIWI and DDH, two conserved domains in AGOs. Phylogenetic analysis indicated that TaAGO1 was possibly derived from different progenitors with its homologous across diverse plant species. The transcripts of TaAGO1 were significantly regulated by the stresses of phosphorus deprivation and dehydration, and exogenous treatment of abscisic acid (ABA), suggesting that this wheat AGO member also exerts roles on mediating above signaling transductions. Southern blotting analysis revealed that genome AA, SS, and DD, three diploids composing of the hexaploid wheat, all harbored two copies of TaAGO1. Down-regulation of TaAGO1 in wheat led to conspicuously phenotypic alterations of the young plantlets, with a variety of abnormal growth features. Taking the results in this study together, it was implicated that TaAGO1 exists as a subset of copies in wheat and plays critical roles on silencing of appropriate target genes via regulation of TaAGO1-MiRNAs complex formation. Key words : Wheat (Triticum aestivum L.), argonaute (AGO) gene 1, cloning, molecular characterization, antisense expression.