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期 刊 ：植物遗传资源学报 2014年 15卷 3期

关键词：苎麻；PCS；克隆；表达分析；镉；植物激素；

Keywords:Ramie, PCS, Clone, Expression analysis, Cadmium, Phytohormone,

摘 要 ：本研究根据苎麻转录组测序中的PCS基因片段，利用RT-PCR结合RACE技术从以中苎1号中克隆了该基因的全长cDNA序列，命名为BnPCS1。该基因的cDNA序列全长为1 956 bp，其中开放读码框长1 512 bp，编码503个氨基酸多肽，预测其分子量和等电点分别为56.02 kD和7.01。与长喙田菁(ACT87974)、百脉根（Q2TSC7）、狼牙刺（AFM38979）、荷花（BAN08523）和杜梨（AEY68568）的PCS氨基酸序列相似性分别为74%、73%、75%、73%和77%。荧光定量PCR分析表明，BnPCS1在根、茎、茎尖、幼叶、成熟叶中均有表达，其中，在成熟叶中的表达量最高，在根中次之，其次为幼叶，在茎中表达量最低，并且该基因受镉和ABA诱导上调表达。

Abstract:The contamination of heavy metals by mining and combustion of fossil fuel has brought about significant deleterious consequences not only to environment but also to human health. Ramie(Boehmeria nivea L.) is a China originated fiber crop that has great ability to tolerate and accumulate heavy metals. To explore the mechanism of ramie to tolerate cadmium, we isolated and analysed a novel gene(BnPCS1) exhibiting high homology with phytochelatin synthase gene(PCS) from Zhongzhu 1 ramie by RT-PCR and RACE methods. The full length sequence and the ORF of BnPCS1 gene is 1 888 bp and 1 512 bp, respectively, which encodes 503 amino acids(56.02 kDa) with a pI value of 6.76. The similarity comparison revealed that the deduced amino acid sequence shares 74%, 73%, 75%, 73% and 77% of homology with Lotus japonicas(Q2TSC7), Nelumbo nucifera(BAN08523), Pyrus betulifolia(AEY68568), Sesbania rostrata(ACT87974) and Sophora viciifolia(AFM38979). Real-time quantitative PCR was used to analyze expression pattern of BnPCS1 in different organs and under Cd, ABA and SA treatment. We found that BnPCS1 was mainly expressed in mature leaf and highly induced in leaf by Cd and ABA treatment, respectively. These results indicated that BnPCS1 may be involved in response of ramie plants to Cd stress. In this study, we succeeded cloned an phytochelatin synthase gene(BnPCS1) and studied in primary level, which established the foundation for the future study in the mechanism of ramie to heavy metal Cd stress.

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