Mercury-induced oxidative stress and impact on antioxidant enzymes in Chlamydomonas reinhardtii
Mercury-induced oxidative stress and impact on antioxidant enzymes in Chlamydomonas reinhardtii
复制标题
汞诱导的氧化应激及其对莱茵衣藻抗氧化酶的影响
DOI：
10.1007/s10646-010-0514-z
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发表时间：
2010-10-01
期刊：
影响因子：
2.7
通讯作者：
Yang, Zhi Min
中科院分区：
文献类型：
--
作者：
Elbaz, Abdelrahman;Wei, Yuan Yuan;Yang, Zhi Min
汞已成为重要的环境污染物，从生态学角度研究绿色藻类中的汞毒性具有重要意义。在高等植物中，汞的积累改变了细胞功能的许多方面。然而，汞对绿色藻类产生有害影响的过程在很大程度上是未知的。在这项研究中，我们进行了一项实验，重点是生物反应的衣原体reinhardtii，一个单细胞模式生物，汞（2+）诱导的毒性。C.将莱因哈氏线虫暴露于培养基中的0、1、2、4、6和8 μM Hg。汞浓度与细胞生长呈负相关。汞处理引起活性氧和过氧化产物的积累。内源脯氨酸水平增加汞暴露的藻类。汞暴露激活超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）。为了深入了解分子响应，进行基于RT-PCR的测定以分析Mn-SOD、CAT和APX的转录丰度。我们的分析表明，基因的表达上调汞暴露，与酶活性的模式相似。此外，还研究了汞对脯氨酸合成的关键酶--β（1）-吡咯啉-5-羧酸合成酶和调节重金属耐受性的酶--血红素加氧酶-1（HO-1）转录量的影响。汞可上调P5 CS和HO-1的表达。这些数据表明，汞诱导的氧化应激是导致生长和抗氧化防御系统紊乱的原因。莱因哈德氏菌
Investigation of mercury toxicology in green algae is of great importance from ecological point of view, because mercury has become a major contaminant in recent years. In higher plants, accumulation of mercury modifies many aspects of cellular functions. However, the process that mercury exerts detrimental effects on green algae is largely unknown. In this study, we performed an experiment focusing on the biological responses of Chlamydomonas reinhardtii, a unicellular model organism, to Hg(2+)-induced toxicity. C. reinhardtii was exposed to 0, 1, 2, 4, 6, and 8 μM Hg in media. Concentrations of Hg were negatively correlated with the cell growth. Treatment with Hg induced accumulation of reactive oxygen species and peroxidative products. Endogenous proline levels increased in Hg-exposed algae. Hg exposure activated superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). To get insights into the molecular response, a RT-PCR-based assay was performed to analyze the transcript abundance of Mn-SOD, CAT and APX. Our analysis revealed that expression of the genes was up-regulated by Hg exposure, with a pattern similar to the enzyme activities. Additional investigation was undertaken on the effect of Hg on the transcript amount of ∆(1)-pyrroline-5-carboxylate synthetase, a key enzyme of proline biosynthesis and on that of heme oxygenase-1 (HO-1), an enzyme regulating heavy metal tolerance. Expressions of both P5CS and HO-1 were up-regulated by Hg. These data indicate that Hg-induced oxidative stress was responsible for the disturbance of the growth and antioxidant defensive systems in C. reinhardtii.