柽柳中一种新型硫氧还蛋白H基因的克隆与鉴定（英文）

Cloning and Identification of a Novel thioredoxin h Gene from Tamarix hisipida

硫氧还蛋白对维持生物体内稳定的氧化还原状态发挥着重要作用。为了研究硫氧还蛋白在非生物胁迫条件下的功能,我们从柽柳的cDNA文库中分离出来一条新的硫氧还蛋白cDNA序列,命名为ThTrx1。生物信息学分析表明,ThTrx1是硫氧还蛋白h亚家族的一个新成员,属于h1亚族。我们采用实时定量RT-PCR的方法检测在不同非生物胁迫(NaCl,PEG,CdCl2,低温和ABA)下,ThTrx1基因在刚毛柽柳根和叶中的表达。结果表明,在NaCl,PEG,CdCl2和ABA处理条件下,ThTrx1在柽柳根和叶中的mRNA水平都是上调表达。而在低温胁迫下,ThTrx1下调表达。我们通过Thrx1基因在大肠杆菌中的表达来分析它对于细菌生长和耐受性的影响。结果表明,含重组质粒的大肠杆菌(pET32a-Trx1)与对照相比,对于盐,金属离子和干旱胁迫体现出更高的耐受性。我们的结果表明,该ThTrx1是参与非生物胁迫应答,并且受依赖ABA信号转导途径的调节。

Thioredoxins play an important role in various cellular processes through redox regulation. We isolated a novel Trx eDNA sequence, ThTrxl, from cDNA libraries of T. hisipida to characterize their functions under abiotic stress. By bioinformatic analysis, ThTrxl is a new member of the thioredoxin h subfamily and belongs to subgroup 1. We used real-time quantitative RT-PCR to examine ThTrxl gene expression in roots and leaves under different abiotic stresses （ NaCl, PEG, CdCl_2, low temperature and ABA）. The mRNA levels of ThTrxl in both leaves and roots were up-regulated under NaCl, PEG, CdCl_2 and ABA treatments. However, the expression of ThTrx1 mRNA decreased during low temperature treatment. We also expressed the ThTrx1 gene in E. coli and examined its effect on bacterial growth and stress tolerance. The E. coli containing recombinant plasmid（pET32a-Trx1 ） was more resistant to salt, metal ions and drought stress that was the control. Therefore, ThTrxl is involved in an abiotic stress response and regulated by ABA-dependent signaling pathways.