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作 者 ：宋晓宏;沙伟*

期 刊 ：植物研究 2014年 34卷 5期 页码：655-663

关键词：毛尖紫萼藓；干旱胁迫；GpSOD；序列分析；基因表达；

Keywords:Grimmia pilifera, drought stress, GpSOD, sequence analysis, gene expression,

摘 要 ：超氧化物歧化酶(SOD)在植物中普遍存在，具有清除自由基、维持活性氧代谢平衡的功能，在植物抗逆中发挥着重要的作用。本研究以耐旱能力极强的毛尖紫萼藓（Grimmia pilifera）为试材，采用RACE技术克隆获得1个超氧化物歧化酶基因SOD的cDNA序列，命名为GpSOD（GenBank登录号：GU989312）。该基因全长726 bp，编码区为465 bp，编码154个氨基酸。序列分析表明：该基因编码蛋白是非分泌性疏水蛋白，具有2个铜锌超氧化物歧化酶位点，属于Sod Cu基因家族，与其他植物超氧化物歧化酶的同源性为68.8%~86.8%。实时定量PCR检测结果显示，虽然GpSOD在干旱及复水条件下均有表达，但GpSOD受干旱诱导表达明显，且复水处理抑制其表达，表明GpSOD蛋白与毛尖紫萼藓响应干旱胁迫的过程密切相关，该结果为进一步寻找高效抗氧化胁迫基因提供前提条件。

Abstract:Superoxide dismutases (SOD) is widespread in plant where it plays a major role in the defense against toxic-reduced oxygen species, and has been proposed to be important for plant stress tolerance. In this study, a full length cDNA sequence of a superoxide dismutase (SOD) gene named GpSOD was cloned from Grimmia pilifera(GenBank accession No. GU989312) using rapid amplification of cDNA ends (RACE). The full length cDNA of GpSOD was 1 115 bp with a 771 bp open reading frame (ORF). Sequence analysis showed that GpSOD is a hydrophobic and non-secretory protein, with two copper-zinc superoxide dismutase sites, and belongs to the Sod Cu families. GpSOD protein shares 68.8%-86.8% homology with SOD proteins from other plants. QRT-PCR analysis showed that although GpSOD was expressed in both dehydration and rehydration, but induced significantly in dehydration, and inhibited in rehydration. The results demonstrated that the GpSOD is closely related to the process of response to drought stress in G.pilifera, which provided premise conditions for oxidative stress genes further seeking.

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