西伯利亚蓼铜伴侣蛋白基因在盐胁迫条件下的表达分析

铜伴侣蛋白是细胞质中负责传递铜离子的一种小分子转运蛋白,在逆境胁迫过程中铜伴侣蛋白的ATX1家族具有消除活性氧的作用．本研究应用RACE技术从西伯利亚蓼中克隆了具有完整编码区的铜伴侣蛋白全长cDNA序列,命名为PsATX-1．PsATX-1基因全长516 bp,其中开放读码框为228 bp,编码75个氨基酸,5′非编码区为83 bp,3′非编码区为204 bp．GenBank中登录号为EU620702．经比对发现,该基因所编码蛋白拥有重金属结合位点MXCXXC,缺少多数高等植物铜伴侣蛋白(CCH)所特有的C末端结构域（CTD）．实时荧光定量PCR分析显示,PsATX-1基因在西伯利亚蓼的地下茎、茎、叶中皆有表达,其中叶中表达量最高;PsATX-1基因受3% NaHCO3胁迫诱导,在不同部位表达模式有差异．

Gene Cloning and RT-PCR express Analysis of copper chaperone protein from Polygonum sibiricum Laxm.under the stress

Copper (Cu) chaperone is a class of small Cu⁺ binding proteins that are required for the Cu homeostasis in cytoplasm, including the ATX1 family carrying antioxidative activities. The full length of ATX1 from Polygonum sibiricum Laxm (PsATX--1, GenBank accession No. EU620702) was isolated by RACE (rapid amplification of cDNA ends) method, which extended 516 bp with an 83 bp 5′untranslated region, a 228 bp open reading frame (ORF) encoding a peptide of 75 amino acid residues, and a 204 bp 3′untranslated region. Similar to most of the plant ATX1 proteins, PsATX-1 includes an N-terminal heavy metal binding site with the signature sequence of “MXCXXC", except lacks the carboxyl terminal domain (CTD) signature sequence. Real-time quantitative PCR revealed that PsATX-1 was expressed in leaves, stem and underground stem, and could be induced by 3% NaHCO3, but the dynamics of the inductions varied in different tissues.