中国红豆杉TcNPR1基因的克隆与功能研究  

Cloning and Function Analysis of theTcNPR1 Gene from Taxus chinesis

作　　者：谢莎[1] 许想平[1] 张蒙[1] 付春华[1,2] 余龙江[1,2] 

机构地区：[1]华中科技大学生命科学与技术学院生物技术系,资源生物学与生物技术研究所,武汉430074 [2]华中科技大学分子生物物理教育部重点实验室,武汉430074

出　　处：《植物科学学报》2014年第4期383-393,共11页Plant Science Journal

基　　金：国家自然科学基金面上项目(31270342)

摘　　要：水杨酸(SA)可诱导红豆杉细胞中紫杉醇的合成,病程相关基因非表达子基因(NPR1)是SA介导的植物系统获得性抗性(SAR)信号途径中的关键信号分子。本研究从中国红豆杉(Taxus chinesis)细胞中克隆了TcNPR1基因,该基因完整的开放阅读框大小为1857 bp,编码蛋白序列由619个氨基酸组成,含有典型的NPR1保守结构域、锌指结构域和锚蛋白结构域。进化树分析发现,TcNPR1蛋白与拟南芥AtNPR3和AtNPR4类蛋白的亲源关系较近。TcNPR1基因表达响应SA、干旱和NaCl胁迫处理,且随着处理时间增加,TcNPR1基因表达量逐渐增大。超表达TcNPR1的转基因烟草植株对干旱的耐受力增强,叶片内可溶性糖含量达43.8 mg/g(FW),比对照高出2倍左右,说明TcNPR1基因具有表达功能,此结果为探究中国红豆杉细胞响应SA诱导大量合成紫杉醇的信号途径提供了依据。Salicylic acid （SA）, a common plant hormone, can increase the biosynthesis of various compounds, such as taxol in Taxus cells. NPR1 is the key gene in SA mediated plant system acquired resistance （SAR） signal pathway. To clarify the regulating mechanism of SA induced taxol biosynthesis, the TcNPR1 gene was isolated from Taxus cells, and was found to contain a 1857 bp QRF （open reading frame）, which may encode a 619 aa protein. Sequence alignment showed TcNPR1 contained typical conserve domains such as Broad-Complex, Tramtrack, and Bric-a-brac/Pox virus and Zinc Finger （BTB/POZ domain）, NPR1/NIMI-like- C terminal and ankyrin repeats. Phylogenetic analysis showed that TcNPR1 had a close relationship with AtNPR3 and AtNPR4 of Arabidopsis. Expression analysis revealed that the expression of the TcNPR1 gene was significantly induced by SA, drought and NaCI. In comparison to the wild type, transgenic tobacco plants over-expressing TcNPR1 showed elevated drought tolerance with soluble sugar increasing to 43.8 mg/g （FW） after 4 d ofdrought treatment, about two times more than the control, revealing that TcNPR1 was a functional protein. The available evidence verified that TcNPR1 may respond to SA and may be involved in systemic acquired resistance （SAR） in Taxus species. Further studies on the TcNPR1 gene are essential for clarifying its function in taxol biosynthesis.

关 键 词：中国红豆杉 病程相关基因非表达子基因(NPR1) 基因克隆 表达分析 

分 类 号：Q943.2[生物学—植物学]