一个亚洲棉MYB家族新基因的克隆及特征分析

Cloning and Characterization of a Noval Gene of MYB Family from Gossypium arboreum L.

【目的】克隆亚洲棉MYB家族的一个新基因(GaMYB2),研究其表达模式,分析其预期编码蛋白。【方法】利用RT-PCR和RACE技术克隆亚洲棉MYB2的cDNA序列全长;应用生物信息学软件分析该基因及预期编码蛋白的特征;采用实时荧光定量PCR技术对该基因的组织特异性和PEG6000模拟干旱胁迫处理下的表达模式进行分析。【结果】从亚洲棉(Gossypium arboreum L.)中克隆了MYB家族的一个新基因MYB2,该基因全长1 117 bp,ORF全长840 bp,编码279个氨基酸,含有MYB保守域,氨基酸的BALSTP分析表明GaMYB2氨基酸序列与已报道的水稻(BAA23338.1)、小麦(AAT37168.1)等的序列有40.50%到68.20%的相似性。亚细胞定位表明该基因在细胞核中表达,实时荧光定量PCR结果表明该基因在根和花中的表达量较高,并且响应17%的PEG6000模拟干旱胁迫处理,上调表达。【结论】GaMYB2是亚洲棉MYB家族的一个新基因,并认为该基因可能在棉花调控干旱胁迫的生理适应过程中发挥重要作用。

[Objective] The objective of this study is to clone a novel gene of MYB family （GaMYB2） from Gossypium arboreum L., to analyze its expression patterns, and to characterize the deduced protein of this gene. [ Method ] The full length of GaMYB2 was cloned by RACE and RT-PCR techniques, the gene sequence obtained and the putative amino acid sequence was analyzed by bioinformatics software. Its expression patterns were analyzed by real-time PCR under normal and PEG6000 stress respectively, which simulated drought tolerance. [Result] The GaMYB2 full length cDNA sequence is 1 117 bp, and the ORF is 840 bp, which encode a deduced protein including 279 amino acid residues. Blastp reseaeh revealed 40.50% to 68.20% similarities between GaMYB2 and other reported species, such as Oryza sativa （BAA23338.1） and Triticum aestivum （AAT37168.1）. Subcellular localization showed that it expressed possibly in cell nucleus. The experiment results of real time PCR exhibited that GaMYB2 could be induced by 17% PEG6000, and had a higher expression level in root and flower than in other tissues. [Conclusion] The GaMYB2, cloned for the first time from G. arboreum L., is a new transcription factor of MBY family, and may play an important role in plant tolerance to drought stress.