Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444, Shanghai, People's Republic of China.
Plant Cell Rep. 2011 Aug;30(8):1503-12. doi: 10.1007/s00299-011-1060-8. Epub 2011 Mar 24.
Peroxiredoxins (Prxs), a group of antioxidant enzymes, are an important component of the oxidative defense system and have been demonstrated to function as peroxidases, sensors of H(2)O(2)-mediated signaling and/or chaperones. In this study, a cDNA library was constructed from a halotolerant alga, Dunaliella viridis, and was used in a functional complementation screen for antioxidative genes in an oxidative sensitive yeast mutant. Two Prx genes, DvPrx1 and DvPrx2, were obtained from this screen. These two genes were classified as type II Prx and 2-Cys Prx based on amino acid sequence and phylogenetic analysis. When over-expressed in yeast cells, both Prx genes were able to confer better oxidative tolerance and decrease the level of reactive oxygen species (ROS). Subcellular localization experiments in tobacco cells revealed that both DvPrx1 and DvPrx2 were localized in the cytosol. The transcription of DvPrx1 and DvPrx2 can be induced by hypersalinity shock, but is not obviously affected by treatment with high levels of oxidant. Our results shed light on the function and regulation of Prx genes from Dunaliella and their potential roles in salt tolerance.
过氧化物酶（Prxs）是抗氧化酶的一个重要组成部分，是氧化防御系统的重要组成部分，其功能被证明为过氧化物酶、H（2）O（2）介导的信号传感器和/或伴侣蛋白。在这项研究中，构建了一株耐盐藻类杜氏盐藻的 cDNA 文库，并用于对氧化敏感酵母突变体中的抗氧化基因进行功能互补筛选。从该筛选中获得了两个 Prx 基因，DvPrx1 和 DvPrx2。这两个基因根据氨基酸序列和系统发育分析被分类为 II 型 Prx 和 2-Cys Prx。当在酵母细胞中过表达时，这两个 Prx 基因都能够赋予更好的氧化耐受性并降低活性氧（ROS）的水平。在烟草细胞中的亚细胞定位实验表明，DvPrx1 和 DvPrx2 都定位于细胞质中。DvPrx1 和 DvPrx2 的转录可以被高渗休克诱导，但不受高水平氧化剂处理的明显影响。我们的结果阐明了来自杜氏盐藻的 Prx 基因的功能和调控及其在耐盐性中的潜在作用。
