盐芥谷胱甘肽过氧化物酶基因（ThGPX6）的克隆及表达分析

谷胱甘肽过氧化物酶在植物响应盐胁迫中具有重要作用。依据盐芥EST序列进行RACE实验,获得1个新的谷胱甘肽过氧化物酶基因,命名为ThGPX6(GenBank注册号为FJ357244)。该基因的cDNA全长892 bp,包含1个长为702bp的开放读码框,编码234个氨基酸。生物信息学分析表明,该蛋白具有植物GPX的典型结构,即GPX催化活性区(NVASKCGLT)和标志性基序(ILAFPCNQF),以及PHGPX特有序列(KWNF(S/T)KFL)。实时荧光定量PCR分析结果表明,ThGPX6在盐芥叶片和根中表达,其表达受NaCl诱导,显示ThGPX6在植物高盐响应中发挥作用。亚细胞定位结果表明,ThGPX6存在于线粒体和内体中的可能性最大,预示着ThGPX6在清除ROS过程中起着重要作用。

Cloning and Expression Analysis of Glutathione Peroxidase 6 (ThGPX6) in Thellungiella halophile

Glutathione peroxidase(GPX)plays an important role in response to salt stress in plant.Through the analysis on EST sequence of Thellungiella halophila,a novel gene exhibiting high homology with plant glutathione peroxidase was discovered and named as ThGPX6(GenBank accession number:FJ357244).ThGPX6 consists of 892 nucleotides,including a single 702bp opening reading frame which encodes a 234-amino acid peptide.Bioinformatics analysis showed that ThGPX6 had typical structures of GPX,such as catalysis region(NVASKCGLT),characteristic motif(ILAFPCNQF)and PHGPX special sequence(KWNF(S/T)KFL).Quantitative real-time PCR analysis revealed that the gene expressed in shoot and root,and could be induced by NaCl in T.halophila.These results showed that the ThGPX6 played a crucial role under salt stress in T.halophila.ThGPX6 is most likely localized in the mitochondria and endosome,suggesting importence of ThGPX6 in the process of cleaning ROS.