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作 者 ：贾园园, 张春蕊, 王玉成, 杨传平, 王超

期 刊 ：植物研究 2016年 36卷 3期 页码：380-387,394

关键词：刚毛柽柳；Na+/H+逆向转运蛋白；胁迫响应；基因表达；

Keywords:Tamarixhispida, Na+/H+antiporter, stressresponses, geneexpression,

摘 要 ：通过对刚毛柽柳(Tamarix hispida)转录组分析,鉴定获得一个Na⁺/H⁺逆向转运蛋白基因,命名为ThSOS1。ThSOS1基因cDNA全长3917 bp,开放阅读框长3498 bp,编码1165个氨基酸,编码蛋白相对分子质量128.8 kDa,理论等电点(PI)为6.42。疏水性分析预测ThSOS1基因编码蛋白N端具有10个跨膜结构域,C端具有一个较长的亲水尾部。ThSOS1氨基酸序列与长叶红砂、藜麦、盐地碱蓬等植物的SOS1序列同源性较高,分别可达92%,73%,72%。系统发育分析表明ThSOS1为质膜型Na⁺/H⁺逆向转运蛋白,与液泡膜型Na⁺/H⁺逆向转运蛋白属于不同分支。实时荧光定量RT-PCR分析显示,该基因受高盐、干旱诱导上调表达,暗示ThSOS1可能在刚毛柽柳抗旱耐盐过程中发挥重要作用。

Abstract:A full length cDNA of a Na⁺/H⁺ antiporter gene (named ThSOS1) gene was isolated from the transcriptome cDNA librarys of Tamarix hispida. ThSOS1 was 3 917 bp in length, including an open reading frame of 3 498 bp which was predicted to encode a polypeptide of 1 165 amino acids. The estimated molecular weight and isoelectric point of the putative protein were 128.8 kDa and 6.42, respectively. By hydrophobic cluster analysis, ThSOS1 contained 10 potential transmembrane domains within the N- terminal protion and a long hydrophilic cytoplasmic tail in the C-terminal protion. By multiple sequence alignment, ThSOS1 show 92%, 73%, and 72% identities in amino acid sequence to plasma membrane Na⁺/H⁺ antiporter genes from Reaumuria trigyna, Chenopodium quinoa and Suaeda salsa. By phylogenetic analysis, ThSOS1 was more related to the plasma membrane-type Na⁺/H⁺ antiporter and clustered distantly with the vacuolar-typed Na⁺/H⁺ antiporter. By quantitative real-time PCR assay, the mRNA levels of ThSOS1 was significantly up-regulated in T.hispida under NaCl and PEG treatments. Therefore, ThSOS1 might play an important role in salt and drought tolerance of T.hispida.

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