为了探讨转录因子在小麦抗旱分子机制中的作用，利用Affymetrix小麦表达谱芯片对渗透胁迫下普通小麦（石麦15）根系和叶片诱导表达谱进行了分析。在表达谱芯片上筛选到1个渗透胁迫诱导表达的MYB转录因子EST序列（GenBank 登录号：BJ264503）。根据该EST序列设计引物筛选石麦15基因组BAC文库，获得1个含有该EST序列的BAC单克隆。以BAC单克隆质粒为模板，通过BAC测序克隆了小麦MYB转录因子基因（TaMYBSM151）及其5'侧翼序列。 TaMYBSM151 的开放读码框长936 bp，编码1个含有311个氨基酸的R1-MYB转录因子。 TaMYBSM151 基因包含3个外显子和2个内含子。在 TaMYBSM151 5' 侧翼序列中，预测出33个脱水响应相关的顺式作用元件。实时定量PCR结果表明，TaMYBSM151 受渗透胁迫诱导表达，但在根和叶中表达模式完全不同。以上结果表明，TaMYBSM151 可能为脱水响应基因。
In order to determine the role of transcriptional factors in drought-resistant molecular mechanism of common wheat,Affymetrix GeneChip Wheat Genome Array was used to analyze the expression-profile of common wheat(Shimai 15)root and leaf under osmotic stress.An osmotic-stress induced EST sequence was identified(GenBank accession No.BJ264503)in the expression-profile chip.One BAC clone was isolated from Shimai 15 genome BAC library using primer pairs designed based on EST-BJ264503 sequence.The MYB transcriptional factor gene(TaMYBSM151)and its 5'-flanking sequence were cloned by sequencing walking using BAC clone plasmid as template.The open reading frame of TaMYBSM151 is 936 bp long coding for a putative 311-amino-acid R1-MYB transcriptional factor. TaMYBSM151 contained three exons and two introns.In 5'-flanking sequence of TaMYBSM151,33 dehydration-response cis-elements were predicted.Real-time RT-PCR revealed that the expression of TaMYBSM151 was induced by osmotic stress,but showed different expression patterns.The results above indicated TaMYBSM151 may be a dehydration-response gene.
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