普陀山苔草植物络合素合成酶CpPCS基因克隆及其在叶中的表达分析

Cloning and expression analysis of CpPCS from Carex putuoshan

以超富集植物普陀山苔草(Carex putuoshan)为材料,克隆其植物络合素合酶基因CpPCS的cDNA全长序列。同时,对其进行重金属胁迫处理,研究该基因在叶中的表达特点。结果表明,该基因cDNA序列全长1 461bp,可编码486个氨基酸;与其它植物同源基因对比显示,它们的氨基酸序列相似性在63%左右;通过构建进化树发现,普陀山苔草CpPCS与小麦(Triticum aestivum)、水稻(Oryza sativa)及芦苇(Phragmites australis)等单子叶植物亲缘关系最近;荧光定量RT-PCR分析结果显示,CpPCS基因及CePCS基因受重金属铅锌胁迫上调表达,其中在叶中的表达量显著增加(P<0.05)。通过普陀山苔草植物络合素合酶蛋白基因进行了克隆鉴定,探讨该基因的结构、进化关系及其参与普陀山苔草重金属胁迫的应答模式,为进一步培育重金属污染土壤修复的植物奠定基础。

The hyperaccumulator Carex putuoshan was used as cloning material for the phytochelatin synthase（PCS）gene,and to characterize its expression following heavy metal stress.The results showed that the cDNA of CpPCS was 1 461 bp in length,and it encoded 486 amino acids with a molecular weight of 53.86 kDa and pI value of 6.12.As compared to other plants,the amino acid sequence similarity was approximately 63%.Phylogenetic analysis of PCS proteins from different species showed those of C.putuoshan were most closely related to those of Oryza sativaand Triticum aestivum.Real-time quantitative PCR analysis indicated that CpPCSand CePCS（Carex oshimensis＇ Evergold＇）genes were expressed in the leaves.The CpPCSand CePCSgenes were up-regulated in Pb and Zn treatments.Additionally,we investigated CpPCSstructure,phylogenetic relationships,and gene expression patterns.Our results indicated that CpPCS might play an important role in heavy metal stress,and could be further utilized in plants.