Expression divergence of TaMBD2 homoeologous genes encoding methyl CpG-binding domain proteins in wheat (Triticum aestivum L.)
Expression divergence of TaMBD2 homoeologous genes encoding methyl CpG-binding domain proteins in wheat (Triticum aestivum L.)
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小麦 (Triticum aestivum L.) 中编码甲基 CpG 结合域蛋白的 TaMBD2 同源基因的表达差异
DOI：
10.1016/j.gene.2010.10.001
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发表时间：
2011-01-15
期刊：
影响因子：
3.5
通讯作者：
Sun, Qixin
中科院分区：
文献类型：
--
作者：
Hu, Zhaorong;Yu, Ying;Sun, Qixin
大多数六倍体小麦基因以源自祖先物种的三重同源物的形式存在。此前，我们分离了 6 个具有开放阅读框的小麦 cDNA，编码甲基 CpG 结合域蛋白（MBD）。本研究获得了3个TaMBD2同源基因的基因组和cDNA序列，并分别定位在5A、5B和5D染色体上。这些序列在编码区和外显子/内含子结构中表现出非常高的保守性，但 cDNA 序列可通过编码区中的 9 bp 插入和 3'-非翻译区 (UTR) 中的大小多态性来区分。通过实时PCR分析每个同源基因在不同发育阶段的不同组织中以及响应非生物胁迫的表达模式。三种同源物的相对 mRNA 丰度在从幼苗到发育种子的不同发育阶段差异很大。最值得注意的是，TaMBD2-5B和TaMBD2-5D对盐胁迫高度敏感，并且TaMBD2-5B在幼苗叶片的低温下特别上调。这些结果为异源多倍体中复制的基因的表达变异提供了进一步的证据。此外，TaMBD2同源基因表达因环境胁迫而发生的变化可能使植物能够更好地应对自然环境中的胁迫。 0 2010 Elsevier B.V. 保留所有权利。
Most hexaploid wheat genes are present as triplicate homoeologs derived from the ancestral species. Previously, we isolated six wheat cDNAs with open reading frame, encoding methyl CpG-binding domain proteins (MBDs). In this study, the genomic and cDNA sequences of three TaMBD2 homoeologous genes were obtained and mapped on chromosomes 5A, 5B and 5D, respectively. These sequences showed a very high conservation in the coding region and the exon/intron structure, but the cDNA sequences are distinguishable by a 9-bp insertion in coding region and a size polymorphism in the 3'-untranslated region (UTR). The expression patterns of each homeologous gene in different tissues of various developmental stages and in response to abiotic stress were analyzed by using real-time PCR. Relative mRNA abundance of the three homoeologs varied considerably in different developmental stages from seedling to developing seeds. Most notably, TaMBD2-5B and TaMBD2-5D were highly responsive to salt stress and TaMBD2-5B was specifically upregulated by low temperature in the seedling leaves. These results provide further evidence for the expression variation of genes duplicated in allopolyploids. Moreover, the variation of TaMBD2 homoeologous gene expression in response to environmental stress may enable plants to better cope with stresses in their natural environments. 0 2010 Elsevier B.V. All rights reserved.