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Santos JP, Li W, Keller AA, Slaveykova VI. Mercury species induce metabolic reprogramming in freshwater diatom Cyclotella meneghiniana. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133245. [PMID: 38150761 DOI: 10.1016/j.jhazmat.2023.133245] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 12/06/2023] [Accepted: 12/10/2023] [Indexed: 12/29/2023]
Abstract
Mercury is a hazardous pollutant of global concern. While advances have been made in identifying the detrimental effects caused by Hg species in phytoplankton, knowledge gaps remain regarding the metabolomic perturbations induced by inorganic mercury (Hg(II)) and monomethylmercury (MeHg) in these organisms. Diatoms represent a major phytoplankton group essential in various global biogeochemical cycles. The current study combined targeted metabolomics, bioaccumulation, and physiological response assays to investigate metabolic perturbations in diatom Cyclotella meneghiniana exposed for 2 h to nanomolar concentrations of Hg(II) and MeHg. Our findings highlight that such exposures induce reprogramming of the metabolism of amino acids, nucleotides, fatty acids, carboxylic acids and antioxidants. These alterations were primarily mercury-species dependent. MeHg exposure induced more pronounced reprogramming of the metabolism of diatoms than Hg(II), which led to less pronounced effects on ROS generation, membrane permeability and chlorophyll concentrations. Hg(II) treatments presented distinct physiological responses, with more robust metabolic perturbations at higher exposures. The present study provides first-time insights into the main metabolic alterations in diatom C. meneghiniana during short-term exposure to Hg species, deepening our understanding of the molecular basis of these perturbations.
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Affiliation(s)
- João P Santos
- University of Geneva, Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environmental Biogeochemistry and Ecotoxicology, 66 Blvd Carl-Vogt, CH 1211 Geneva, Switzerland.
| | - Weiwei Li
- Bren School of Environmental Science & Management, University of California, Santa Barbara, CA 93106-5131, United States
| | - Arturo A Keller
- Bren School of Environmental Science & Management, University of California, Santa Barbara, CA 93106-5131, United States
| | - Vera I Slaveykova
- University of Geneva, Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environmental Biogeochemistry and Ecotoxicology, 66 Blvd Carl-Vogt, CH 1211 Geneva, Switzerland.
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Mosleminejad N, Ghasemi Z, Johari SA. Ionic and nanoparticulate silver alleviate the toxicity of inorganic mercury in marine microalga Chaetoceros muelleri. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:19206-19225. [PMID: 38355858 DOI: 10.1007/s11356-024-32120-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 01/17/2024] [Indexed: 02/16/2024]
Abstract
Toxicological effects of silver nanoparticles (SNPs) in different organisms have been studied; however, interactions of SNPs with other environmental pollutants such as mercury are poorly understood. Herein, bioassay tests were performed according to ΟECD 201 guideline to assess the toxic effects induced by mercury ions (mercury chloride, MCl) on the marine microalga Chaetoceros muelleri in the presence of SNPs or silver ions (silver nitrate, SN). Acute toxicity tests displayed that the presence of SNPs or SN (0.01 mg L-1) significantly reduced the toxicity of MCl (0.001, 0.01, 0.1, 1, 10, and 100 mg L-1) and increased the IC50 of MCl from 0.072 ± 0.014 to 0.381 ± 0.029 and 0.676 ± 0.034 mg L-1, respectively. In the presence of SN or SNPs, the mercury-reducing effect on algal population growth significantly decreased. Considering the increase of IC50, the mercury toxicity decreased approximately 5.44 and 9.66 times in the presence of SNPs or SN, respectively. The chlorophyll a and c contents decreased at all exposures; however, the decrease by MCl-SNPs and MCl-SN was significantly less than MCl except at 1 mg L-1. The lowering effect of MCl-SN on chlorophyll contents was less than MCl and MCl-SNPs. MCl exposure induced significant raises in total protein content (TPC) at concentrations < 0.01mg L-1, with a maximum of ~ 70.83% attained at 100 mg L-1. The effects of MCl-SNPs and MCl-SN on TPC were significantly less than MCl. Total lipid content (TLC) at all MCl concentrations was higher than the control, while at coexposure to MCl-SN, TLC did not change until 0.01 mg L-1 compared with the control. The effects of MCl-SN and MCL-SNPs on TPC and TLC were in line with toxicity results, and were significantly less than those of MCl individually, confirming their antagonistic effects on MCl. The morphological changes of algal cells and mercury content of the cell wall at MCl-SN and MCl-SNPs were mitigated compared with MCl exposure. These findings highlight the mitigatory impacts of silver species on mercury toxicity, emphasizing the need for better realizing the mixture toxicity effects of pollutants in the water ecosystem.
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Affiliation(s)
- Nasim Mosleminejad
- Department of Fisheries, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran
| | - Zahra Ghasemi
- Department of Fisheries, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran.
- Nanoscience, Nanotechnology, and Advanced Materials Research Centre, University of Hormozgan, Bandar Abbas, Iran.
| | - Seyed Ali Johari
- Department of Fisheries, Faculty of Natural Resources, University of Kurdistan, Sanandaj, Kurdistan, Iran
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Millet RT, Santos JP, Slaveykova VI. Exploring the subcellular distribution of mercury in green alga Chlamydomonas reinhardtii and diatom Cyclotella meneghiniana: A comparative study. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2024; 267:106836. [PMID: 38232614 DOI: 10.1016/j.aquatox.2024.106836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/09/2024] [Accepted: 01/11/2024] [Indexed: 01/19/2024]
Abstract
Mercury (Hg) is a priority pollutant of global concern because of its toxicity, its ability to bioaccumulate throughout the food web and reach significant concentrations in top predators. Phytoplankton bioconcentrate large amounts of Hg and play a key role in the entry of Hg into the aquatic food web. However, the subcellular distribution of Hg in freshwater phytoplankton, known to affect it toxicity and trophic transfer is understudied. The present study aimed at investigating the accumulation of inorganic Hg (iHg) and its subcellular distribution in freshwater phytoplankton species. To this end green alga Chlamydomonas reinhardtii and diatom Cyclotella meneghiniana were exposed to 10 and 100 nM of iHg for 2 h. The concentrations of Hg in the adsorbed, intracellular and subcellular (granules, debris, organelles, heat-stable peptides (HSP) and heat-denaturable proteins (HDP)) fractions were determined. The results showed that C. meneghiniana accumulated more Hg compared to C. reinhardtii at both iHg exposure concentrations (10 nM: 4.41 ± 0.74 vs. 1.10 ± 0.25 amol cell-1; 100 nM: 79.35 ± 10.78 vs. 38.31 ± 4.15 amol cell-1). The evaluation of the subcellular distribution of Hg, revealed that the majority of Hg was concentrated in the organelles fraction (59.7 % and 74.6 %) in the green algae. In the diatom, Hg was mainly found in the organelles (40.9 % and 33.3%) and in the HSP fractions (26.8 % and 40.1 %). The proportion of Hg in HDP fraction decreased in favor of the organelles fraction in C. reinhardtii when the exposure concentration increased, whereas the proportions in the debris and organelles fractions decreased in favor of HSP fraction in C. meneghiniana. This study provides pioneering information on the subcellular distribution of Hg within in freshwater phytoplankton, a knowledge that is essential to understand the toxicity and trophic transfer of Hg in contaminated aquatic environment.
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Affiliation(s)
- Rémy T Millet
- University of Geneva, Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environmental Biogeochemistry and Ecotoxicology, 66 Blvd Carl-Vogt, CH 1211 Geneva, Switzerland
| | - João P Santos
- University of Geneva, Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environmental Biogeochemistry and Ecotoxicology, 66 Blvd Carl-Vogt, CH 1211 Geneva, Switzerland
| | - Vera I Slaveykova
- University of Geneva, Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environmental Biogeochemistry and Ecotoxicology, 66 Blvd Carl-Vogt, CH 1211 Geneva, Switzerland.
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Gojkovic Z, Simansky S, Sanabria A, Márová I, Garbayo I, Vílchez C. Interaction of Naturally Occurring Phytoplankton with the Biogeochemical Cycling of Mercury in Aquatic Environments and Its Effects on Global Hg Pollution and Public Health. Microorganisms 2023; 11:2034. [PMID: 37630594 PMCID: PMC10458190 DOI: 10.3390/microorganisms11082034] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 08/02/2023] [Accepted: 08/05/2023] [Indexed: 08/27/2023] Open
Abstract
The biogeochemical cycling of mercury in aquatic environments is a complex process driven by various factors, such as ambient temperature, seasonal variations, methylating bacteria activity, dissolved oxygen levels, and Hg interaction with dissolved organic matter (DOM). As a consequence, part of the Hg contamination from anthropogenic activity that was buried in sediments is reinserted into water columns mainly in highly toxic organic Hg forms (methylmercury, dimethylmercury, etc.). This is especially prominent in the coastal shallow waters of industrial regions worldwide. The main entrance point of these highly toxic Hg forms in the aquatic food web is the naturally occurring phytoplankton. Hg availability, intake, effect on population size, cell toxicity, eventual biotransformation, and intracellular stability in phytoplankton are of the greatest importance for human health, having in mind that such Hg incorporated inside the phytoplankton cells due to biomagnification effects eventually ends up in aquatic wildlife, fish, seafood, and in the human diet. This review summarizes recent findings on the topic of organic Hg form interaction with natural phytoplankton and offers new insight into the matter with possible directions of future research for the prevention of Hg biomagnification in the scope of climate change and global pollution increase scenarios.
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Affiliation(s)
- Zivan Gojkovic
- Algae Biotechnology Group, CIDERTA, University of Huelva, 21007 Huelva, Spain; (A.S.); (I.G.); (C.V.)
| | - Samuel Simansky
- Faculty of Chemistry, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic; (S.S.); (I.M.)
| | - Alain Sanabria
- Algae Biotechnology Group, CIDERTA, University of Huelva, 21007 Huelva, Spain; (A.S.); (I.G.); (C.V.)
| | - Ivana Márová
- Faculty of Chemistry, Brno University of Technology, Purkynova 118, 61200 Brno, Czech Republic; (S.S.); (I.M.)
| | - Inés Garbayo
- Algae Biotechnology Group, CIDERTA, University of Huelva, 21007 Huelva, Spain; (A.S.); (I.G.); (C.V.)
| | - Carlos Vílchez
- Algae Biotechnology Group, CIDERTA, University of Huelva, 21007 Huelva, Spain; (A.S.); (I.G.); (C.V.)
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Wu Y, Zuo C, Zhang W, Zhang L. Selenium alleviates cadmium and copper toxicity in Gracilaria lemaneiformis (rhodophyta) with contrasting detoxification strategies. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 259:106545. [PMID: 37120956 DOI: 10.1016/j.aquatox.2023.106545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/24/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023]
Abstract
Selenium (Se) is a beneficial element for plants, and can be used to mitigate the toxicity of heavy metals. However, the detoxification of Se in macroalgae, a crucial part of aquatic ecosystem productivity, has rarely been reported. In the present study, a red macroalga Gracilaria lemaneiformis was exposed to non-essential metal cadmium (Cd) or essential metal copper (Cu) with addition of different levels of Se. We then examined the changes in growth rate, metal accumulation, metal uptake rate, subcellular distribution, as well as thiol compound induction in this alga. Se addition alleviated Cd/Cu-induced stress in G. lemaneiformis by regulating cellular metal accumulation and intracellular detoxification. Specifically, supplementation of low-level Se displayed a significant decrease in Cd accumulation, and thus alleviated the growth inhibition induced by Cd. This may be caused by the inhibitory effect of endogenous Se instead of exogenous Se on Cd uptake. Although Se addition increased bioaccumulation of Cu in G. lemaneiformis, the important intracellular metal chelators, phytochelatins (PCs), were massively induced to alleviate Cu-induced growth inhibition. High-dose Se addition did not deteriorate but failed to normalize the growth of algae under metal stress conditions. Reduction in Cd accumulation or induction of PCs by Cu could not suppress the toxicity of Se above safe levels. Se addition also altered metal subcellular distribution in G. lemaneiformis, which might affect the subsequent metal trophic transfer. Our results demonstrated that the detoxification strategies of Se between Cd and Cu were different in macroalgae. Elucidating the protective mechanisms of Se against metal stress may help us better apply Se to regulate metal accumulation, toxicity, and transfer in aquatic environment.
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Affiliation(s)
- Yun Wu
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology (NUIST), Nanjing 210044, China
| | - Chenchen Zuo
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology (NUIST), Nanjing 210044, China
| | - Wei Zhang
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Li Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
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Tang W, He M, Chen B, Ruan G, Xia Y, Xu P, Song G, Bi Y, Hu B. Investigation of toxic effect of mercury on Microcystis aeruginosa: Correlation between intracellular mercury content at single cells level and algae physiological responses. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159894. [PMID: 36336050 DOI: 10.1016/j.scitotenv.2022.159894] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 06/16/2023]
Abstract
Single-cell studies can help to understand individual differences and obtain atypical cellular characteristics in view of cellular heterogeneity. Herein, the accumulation of mercury (Hg) in single algae cells was studied by droplet chip-time resolved inductively coupled plasma mass spectrometry analytical system, and the relation of Hg accumulation to the physiological responses of algae cell was explored. When low concentrations of Hg2+ (5-20 μg/L) were used in the exposure experiment, the content of Hg in single cells increased in first 2 h, then decreased with further increase of exposure time to 96 h, probably due to the growth dilution effect of the algae. When exposed to 30 μg/L Hg2+, the uptake of Hg by individual cells increased over time, which was associated with increased cell membrane permeability. The exposure to Hg2+ (5-30 μg/L) inhibited the growth of algae in a concentration-dependent manner and serious growth inhibition occurred under the exposure concentration of 30 μg/L. While the exposure concentration was lower than 20 μg/L, algal cells exhibited a recover tendency due to the self-protection mechanism of algal cells. Bivariate results showed that intracellular Hg accumulation was significantly negatively correlated with cells growth in terms of OD680, photosynthetic pigments, Fv/Fm and PIabs. On the contrast, reactive oxygen species content, superoxide dismutase activity, and cell membrane permeability were significantly positively correlated with the accumulation of intracellular Hg. These results are helpful to further understand the toxic effect of Hg on algae.
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Affiliation(s)
- Wenxiao Tang
- Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Man He
- Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Beibei Chen
- Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Gang Ruan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yixue Xia
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Pingping Xu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Gaofei Song
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yonghong Bi
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Bin Hu
- Department of Chemistry, Wuhan University, Wuhan 430072, China.
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Díaz S, Aguilera Á, de Figueras CG, de Francisco P, Olsson S, Puente-Sánchez F, González-Pastor JE. Heterologous Expression of the Phytochelatin Synthase CaPCS2 from Chlamydomonas acidophila and Its Effect on Different Stress Factors in Escherichia coli. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19137692. [PMID: 35805349 PMCID: PMC9265389 DOI: 10.3390/ijerph19137692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/19/2022] [Accepted: 06/21/2022] [Indexed: 11/19/2022]
Abstract
Phytochelatins (PCs) are cysteine-rich small peptides, enzymatically synthesized from reduced glutathione (GSH) by cytosolic enzyme phytochelatin synthase (PCS). The open reading frame (ORF) of the phytochelatin synthase CaPCS2 gene from the microalgae Chlamydomonas acidophila was heterologously expressed in Escherichia coli strain DH5α, to analyze its role in protection against various abiotic agents that cause cellular stress. The transformed E. coli strain showed increased tolerance to exposure to different heavy metals (HMs) and arsenic (As), as well as to acidic pH and exposure to UVB, salt, or perchlorate. In addition to metal detoxification activity, new functions have also been reported for PCS and PCs. According to the results obtained in this work, the heterologous expression of CaPCS2 in E. coli provides protection against oxidative stress produced by metals and exposure to different ROS-inducing agents. However, the function of this PCS is not related to HM bioaccumulation.
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Affiliation(s)
- Silvia Díaz
- Department of Genetics, Physiology and Microbiology, Faculty of Biology, C. José Antonio Novais, 12, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
- Correspondence:
| | - Ángeles Aguilera
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Carolina G. de Figueras
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Patricia de Francisco
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Sanna Olsson
- Department of Forest Ecology and Genetics, Forest Research Centre (INIA, CSIC), Carretera de La Coruña, km 7.5, 28040 Madrid, Spain;
| | - Fernando Puente-Sánchez
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, 756 51 Uppsala, Sweden;
| | - José Eduardo González-Pastor
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
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Kim YO, Gwon Y, Kim J. Exogenous Cysteine Improves Mercury Uptake and Tolerance in Arabidopsis by Regulating the Expression of Heavy Metal Chelators and Antioxidative Enzymes. FRONTIERS IN PLANT SCIENCE 2022; 13:898247. [PMID: 35755654 PMCID: PMC9231614 DOI: 10.3389/fpls.2022.898247] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/24/2022] [Indexed: 05/04/2023]
Abstract
Cysteine (Cys) is an essential amino acid component of the major heavy metal chelators, such as glutathione (GSH), metallothioneins (MTs), and phytochelatins (PCs), which are involved in the pathways of mercury (Hg) tolerance in plants. However, the mechanism through which Cys facilitates Hg tolerance in plants remains largely unclear. In this study, we investigated the effects of exogenous Cys on Hg uptake in the seedlings, roots, and shoots of Arabidopsis throughout 6 and 36 h of Hg exposure and on the regulation of Hg detoxification by heavy metal chelators and antioxidative enzymes. The results showed that exogenous Cys significantly improved Hg tolerance during the germination and seedling growth stages in Arabidopsis. Exogenous Cys significantly promoted Hg uptake in Arabidopsis roots by upregulating the expression of the Cys transporter gene AtLHT1, resulting in increased Hg accumulation in the roots and seedlings. In Arabidopsis seedlings, exogenous Cys further increased the Hg-induced glutathione synthase (GS1 and GS2) transcript levels, and the Hg and Hg + Cys treatments greatly upregulated MT3 expression after 36 h exposure. In the roots, MT3 was also significantly upregulated by treatment of 36 h of Hg or Hg + Cys. Notably, in the shoots, MT2a expression was rapidly induced (10-fold) in Hg presence and further markedly increased (20-fold) by exogenous Cys. Moreover, in the seedlings, exogenous Cys upregulated the transcripts of all superoxide dismutase (CuSOD1, CuSOD2, MnSOD1, FeSOD1, FeSOD2, and FeSOD3) within 6 h and subsequently increased the Hg-induced GR1 and GR2 transcript levels at 36 h, all of which could eliminate the promotion of reactive oxygen species production and cell damage caused by Hg. Additionally, exogenous Cys upregulated all the antioxidative genes rapidly in the roots and subsequently increased the expression of CuSOD1, CuSOD2, and MnSOD1 in the shoots. These results indicate that exogenous Cys regulates the transcript levels of heavy metal chelators and antioxidative enzymes differently in a time- and organ-specific manner under Hg stress. Taken together, our study elucidates the positive functional roles of exogenous Cys in the Hg uptake and tolerance mechanisms of Arabidopsis.
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Affiliation(s)
- Yeon-Ok Kim
- Interdisciplinary Program in IT-Bio Convergence System, Chonnam National University, Gwangju, South Korea
- *Correspondence: Yeon-Ok Kim, ;
| | - Yonghyun Gwon
- Interdisciplinary Program in IT-Bio Convergence System, Chonnam National University, Gwangju, South Korea
- Department of Convergence Biosystems Engineering, Chonnam National University, Gwangju, South Korea
- Department of Rural and Biosystems Engineering, Chonnam National University, Gwangju, South Korea
| | - Jangho Kim
- Interdisciplinary Program in IT-Bio Convergence System, Chonnam National University, Gwangju, South Korea
- Department of Convergence Biosystems Engineering, Chonnam National University, Gwangju, South Korea
- Department of Rural and Biosystems Engineering, Chonnam National University, Gwangju, South Korea
- Jangho Kim,
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9
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Garcia-Calleja J, Cossart T, Pedrero Z, Santos JP, Ouerdane L, Tessier E, Slaveykova VI, Amouroux D. Determination of the Intracellular Complexation of Inorganic and Methylmercury in Cyanobacterium Synechocystis sp. PCC 6803. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:13971-13979. [PMID: 34591446 DOI: 10.1021/acs.est.1c01732] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Understanding of mercury (Hg) complexation with low molecular weight (LMW) bioligands will help elucidate its speciation. In natural waters, the rate of this complexation is governed by physicochemical, geochemical, and biochemical parameters. However, the role of bioligands involved in Hg intracellular handling by aquatic microorganisms is not well documented. Here, we combine the use of isotopically labeled Hg species (inorganic and monomethylmercury, iHg and MeHg) with gas or liquid chromatography coupling to elemental and molecular mass spectrometry to explore the role of intracellular biogenic ligands involved in iHg and MeHg speciation in cyanobacterium Synechocystis sp. PCC 6803, a representative phytoplankton species. This approach allowed to track resulting metabolic and newly found intracellular Hg biocomplexes (e.g., organic thiols) in Synechocystis sp. PCC 6803 finding different intracellular Hg species binding affinities with both high and low molecular weight (HMW and LMW) bioligands in the exponential and stationary phase. Furthermore, the parallel detection with both elemental and molecular ionization sources allowed the sensitive detection and molecular identification of glutathione (GSH) as the main low molecular weight binding ligand to iHg ((GS)2-Hg) and MeHg (GS-MeHg) in the cytosolic fraction. Such a novel experimental approach expands our knowledge on the role of biogenic ligands involved in iHg and MeHg intracellular handling in cyanobacteria.
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Affiliation(s)
- Javier Garcia-Calleja
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les matériaux, Pau 64000, France
| | - Thibaut Cossart
- Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, Uni Carl Vogt, 66 Bvd. Carl Vogt, 1205 Geneva, Switzerland
| | - Zoyne Pedrero
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les matériaux, Pau 64000, France
| | - João P Santos
- Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, Uni Carl Vogt, 66 Bvd. Carl Vogt, 1205 Geneva, Switzerland
| | - Laurent Ouerdane
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les matériaux, Pau 64000, France
| | - Emmanuel Tessier
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les matériaux, Pau 64000, France
| | - Vera I Slaveykova
- Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, Uni Carl Vogt, 66 Bvd. Carl Vogt, 1205 Geneva, Switzerland
| | - David Amouroux
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les matériaux, Pau 64000, France
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10
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Barón-Sola Á, Toledo-Basantes M, Arana-Gandía M, Martínez F, Ortega-Villasante C, Dučić T, Yousef I, Hernández LE. Synchrotron Radiation-Fourier Transformed Infrared microspectroscopy (μSR-FTIR) reveals multiple metabolism alterations in microalgae induced by cadmium and mercury. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126502. [PMID: 34214848 DOI: 10.1016/j.jhazmat.2021.126502] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 06/13/2023]
Abstract
Toxic metals such as cadmium (Cd) and mercury (Hg) represent a threat to photosynthetic organisms of polluted aquatic ecosystems, and knowledge about mechanisms of toxicity is essential for appropriate assessment of environmental risks. We used Synchrotron Radiation-Fourier Transformed Infrared microspectroscopy (μSR-FTIR) to characterise major changes of biomolecules caused by Cd and Hg in the model green microalga Chlamydomonas reinhardtii. μSR-FTIR showed several metabolic alterations in different biochemical groups such as carbohydrates, proteins, and lipids in a time-dose dependent manner, with the strongest changes occurring at concentrations above 10 μM Cd and 15 μM Hg after short-term (24 h) treatments. This occurred in a context where metals triggered intracellular oxidative stress and chloroplast damage, along with autophagy induction by overexpressing AUTOPHAGY-RELATED PROTEIN 8 (ATG8). Thin layer chromatography analysis confirmed that toxic metals promoted remarkable changes in lipid profile, with higher degree of esterified fatty acid unsaturation as detected by gas chromatography coupled with mass spectrometry. Under Cd stress, there was specifically higher unsaturation of free fatty acids, while Hg led to stronger unsaturation in monogalactosyldiacylglycerol. μSR-FTIR spectroscopy proved as a valuable tool to identify biochemical alterations in microalgae, information that could be exploited to optimise approaches for metal decontamination.
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Affiliation(s)
- Ángel Barón-Sola
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - Margarita Toledo-Basantes
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - María Arana-Gandía
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - Flor Martínez
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - Cristina Ortega-Villasante
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - Tanja Dučić
- CELLS ALBA, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, Barcelona, Spain
| | - Ibraheem Yousef
- CELLS ALBA, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, Barcelona, Spain
| | - Luis E Hernández
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain.
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Slaveykova VI, Majumdar S, Regier N, Li W, Keller AA. Metabolomic Responses of Green Alga Chlamydomonas reinhardtii Exposed to Sublethal Concentrations of Inorganic and Methylmercury. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3876-3887. [PMID: 33631933 DOI: 10.1021/acs.est.0c08416] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Metabolomics characterizes low-molecular-weight molecules involved in different biochemical reactions and provides an integrated assessment of the physiological state of an organism. By using liquid chromatography-mass spectrometry targeted metabolomics, we examined the response of green alga Chlamydomonas reinhardtii to sublethal concentrations of inorganic mercury (IHg) and monomethylmercury (MeHg). We quantified the changes in the levels of 93 metabolites preselected based on the disturbed metabolic pathways obtained in a previous transcriptomics study. Metabolites are downstream products of the gene transcription; hence, metabolite quantification provided information about the biochemical status of the algal cells exposed to Hg compounds. The results showed that the alga adjusts its metabolism during 2 h exposure to 5 × 10-9 and 5 × 10-8 mol L-1 IHg and MeHg by increasing the level of various metabolites involved in amino acid and nucleotide metabolism, photorespiration, and tricarboxylic acid (TCA) cycle, as well as the metabolism of fatty acids, carbohydrates, and antioxidants. Most of the metabolic perturbations in the alga were common for IHg and MeHg treatments. However, the exposure to IHg resulted in more pronounced perturbations in the fatty acid and TCA metabolism as compared with the exposure to MeHg. The observed metabolic perturbations were generally consistent with our previously published transcriptomics results for C. reinhardtii exposed to the comparable level of IHg and MeHg. The results highlight the potential of metabolomics for toxicity evaluation, especially to detect effects at an early stage of exposure prior to their physiological appearance.
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Affiliation(s)
- Vera I Slaveykova
- Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environmental Biogeochemistry and Ecotoxicology, University of Geneva, Uni Carl Vogt, 66 Blvd Carl-Vogt, Geneva CH 1211, Switzerland
| | - Sanghamitra Majumdar
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, California 93106-5131, United States
| | - Nicole Regier
- Faculty of Sciences, Earth and Environment Sciences, Department F.-A. Forel for Environmental and Aquatic Sciences, Environmental Biogeochemistry and Ecotoxicology, University of Geneva, Uni Carl Vogt, 66 Blvd Carl-Vogt, Geneva CH 1211, Switzerland
| | - Weiwei Li
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, California 93106-5131, United States
| | - Arturo A Keller
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, California 93106-5131, United States
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Xie P, Ho SH, Xiao QY, Xu XJ, Zhao L, Zhou X, Lee DJ, Ren NQ, Chen C. Revealing the role of nitrate on sulfide removal coupled with bioenergy production in Chlamydomonas sp. Tai-03: Metabolic pathways and mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2020; 399:123115. [PMID: 32937723 DOI: 10.1016/j.jhazmat.2020.123115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/23/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
Recently, simultaneous sulfide removal and bioenergy production by microalgal treatment have attracted growing attention. However, the response of nitrogen metabolism to the sulfide-removal process has yet to be explored. Here, variable levels of sulfide could be completely removed by Chlamydomonas sp. Tai-03 under both high and low nitrate conditions in synthetic wastewaters. The highest sulfide removal rate of 5.56 mg-S L-1 h-1 was achieved with the addition of 100 mg L-1 sulfide in the presence of high nitrate. Meanwhile, sulfide was chemically oxidized to sulfate and then ingested by microalgae. Interestingly, sulfide-removal efficiency critically depended on nitrate concentration. Sulfide can also enhance the ability of microalgae to assimilate nitrogen. Based on the analysis of sulfur- and nitrogen-related metabolic profiling, serine as a precursor decreased by 94 % under low levels of nitrate, which induced the significant inhibition of cysteine and methionine biosynthesis. The results indicated that nitrogen source played a critical role in the sulfur cycle because of the positive relationship between the aforementioned metabolic processes and nitrate concentration. Additionally, sulfide can improve lipid and carbohydrate productivity under high levels of nitrate. This study enhances our understanding of the mechanisms underlying the simultaneous removal of sulfide and alternative bioenergy production.
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Affiliation(s)
- Peng Xie
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, HeiLongjiang Province 150090, China
| | - Shih-Hsin Ho
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, HeiLongjiang Province 150090, China
| | - Qing-Yang Xiao
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, HeiLongjiang Province 150090, China
| | - Xi-Jun Xu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, HeiLongjiang Province 150090, China
| | - Lei Zhao
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, HeiLongjiang Province 150090, China
| | - Xu Zhou
- Engineering Laboratory of Microalgal Bioenergy, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, HeiLongjiang Province 150090, China
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, HeiLongjiang Province 150090, China.
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Wu Y, Yuan Y, Yuan H, Zhang W, Zhang L. Predicting cadmium toxicity with the kinetics of phytochelatin induction in a marine diatom. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 207:101-109. [PMID: 30557755 DOI: 10.1016/j.aquatox.2018.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/19/2018] [Accepted: 12/09/2018] [Indexed: 06/09/2023]
Abstract
Phytochelatin (PC) synthesis is thought to be a rapid and specific response to metal exposure in marine phytoplankton, but its potential as a predictor of metal toxicity is far from conclusive. Thus this research examines the bioaccumulation, PC induction, and toxicity of Cadmium (Cd) in Thalassiosira weissflogii, a coastal diatom under varying nutrient conditions. Nitrogen limitation strongly inhibited Cd uptake and PC induction at the same [Cd2+] level, and increased metal sensitivity. Conversely, phosphorus limitation had little influence on Cd accumulation and PC induction, yet also enhanced metal effect on growth. Differential growth inhibitions were correlated with [Cd2+], intracellular Cd concentration, PC concentration, the kinetics of Cd uptake and PC induction, respectively. It was found that stronger interrelations existed between kinetic rates (both Cd uptake and PC synthesis) and Cd sensitivity than between the static concentrations (Cd and PC) and growth inhibition. Moreover, according to the calculated median inhibition concentration (IC50), median effective uptake rate of Cd, as well as median effective induction rate of PCs, the latter two showed the smallest variation when nutrients were varied (1.4-1.9 fold). Our study set out the first step toward considering the use of PC synthesis kinetics to predict metal toxicity for phytoplankton.
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Affiliation(s)
- Yun Wu
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology (NUIST), Nanjing, 210044, China; Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Yue Yuan
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology (NUIST), Nanjing, 210044, China
| | - Hezhong Yuan
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (AEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology (NUIST), Nanjing, 210044, China
| | - Wei Zhang
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou 510006, China
| | - Li Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
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14
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Wang Y, Zhang C, Zheng Y, Ge Y, Yu X. Simple, Rapid, and Sensitive Determination of Thiols by Liquid Chromatography with Fluorescence Detection. ANAL LETT 2019. [DOI: 10.1080/00032719.2018.1548020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Ya Wang
- Jiangsu Key Laboratory for Food Quality and Safety—State Key Laboratory Cultivation Base, Ministry of Science and Technology, Nanjing, China
- Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Chunhua Zhang
- Demonstration Laboratory of Element and Life Science Research, Laboratory Centre of Life Science, College of Life Science, Nanjing Agricultural University, Nanjing, China
| | - Yanheng Zheng
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Ying Ge
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xiangyang Yu
- Jiangsu Key Laboratory for Food Quality and Safety—State Key Laboratory Cultivation Base, Ministry of Science and Technology, Nanjing, China
- Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
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15
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Samadani M, Dewez D. Effect of mercury on the polyphosphate level of alga Chlamydomonas reinhardtii. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 240:506-513. [PMID: 29754100 DOI: 10.1016/j.envpol.2018.04.141] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 04/25/2018] [Accepted: 04/30/2018] [Indexed: 06/08/2023]
Abstract
In this study, the accumulation and toxicity effect of 1-7 μM of Hg was determined during 24-72 h on two strains of Chlamydomonas reinhardtii, CC-125 and CC-503 as a cell wall-deficient mutant, by monitoring the growth rate and the maximum quantum yield of Photosystem II. In addition, the level of extracytoplasmic polyphosphates (polyP related to the cell wall) was determined to understand the polyP physiological role in Hg-treated algal cells. The results showed that the polyP level was higher in the strain CC-125 compared to CC-503. When algal cells were exposed to 1 and 3 μM of Hg, the accumulation of Hg was correlated with the degradation of polyP for both strains. These results suggested that the degradation of polyP participated in the sequestration of Hg. In fact, this mechanism might explain at 72 h the recovery of the polyP level, the efficiency of maximum PSII quantum yield, the low inhibition of growth rate, and the low accumulated Hg in algal biomass. Under the effect of 5 and 7 μM of Hg, the degradation of polyP was complete and could not be recovered, which was caused by a high accumulation and toxicity of Hg already at 24 h. Our results demonstrated that the change of polyP level was correlated with the accumulation and effect of Hg on algal cells during 24-72 h, which can be used as a biomarker of Hg toxicity. Therefore, this study suggested that extracytoplasmic polyP in C. reinhardtii contributed to the cellular tolerance for Hg.
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Affiliation(s)
- Mahshid Samadani
- Laboratory of Environmental & Analytical Biochemistry of Contaminants, Department of Chemistry, University of Quebec in Montreal, Canada
| | - David Dewez
- Laboratory of Environmental & Analytical Biochemistry of Contaminants, Department of Chemistry, University of Quebec in Montreal, Canada.
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16
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Beauvais-Flück R, Slaveykova VI, Skyllberg U, Cosio C. Molecular Effects, Speciation, and Competition of Inorganic and Methyl Mercury in the Aquatic Plant Elodea nuttallii. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8876-8884. [PMID: 29984984 DOI: 10.1021/acs.est.8b02124] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Mercury (Hg) remains hazardous in aquatic environments because of its biomagnification in food webs. Nonetheless, Hg uptake and impact in primary producers is still poorly understood. Here, we compared the cellular toxicity of inorganic and methyl Hg (IHg and MeHg, respectively) in the aquatic plant Elodea nuttallii. IHg and MeHg regulated contigs involved in similar categories (e.g., energy metabolism, development, transport, secondary metabolism), but MeHg regulated more contigs, supporting a higher molecular impact than IHg. At the organism level, MeHg induced antioxidants, while IHg decreased chlorophyll content. The uptake of Hg and expression of a subset of contigs was subsequently studied in complex media. Measured uptake pointed to a contrasted impact of cell walls and copper (Cu) on IHg and MeHg. Using a speciation modeling, differences in uptake were attributed to the differences in affinities of IHg and MeHg to organic matter in relation to Cu speciation. We also identified a distinct gene expression signature for IHg, MeHg, and Cu, further supporting different molecular toxicity of these trace elements. Our data provided fundamental knowledge on IHg and MeHg uptake in a key aquatic primary producer and confirmed the potential of transcriptomics to assess Hg exposure in environmentally realistic systems.
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Affiliation(s)
- Rébecca Beauvais-Flück
- Department F.-A. Forel for environmental and aquatic sciences, Earth and Environmental Sciences, Faculty of Sciences , University of Geneva , CH-1211 Geneva , Switzerland
| | - Vera I Slaveykova
- Department F.-A. Forel for environmental and aquatic sciences, Earth and Environmental Sciences, Faculty of Sciences , University of Geneva , CH-1211 Geneva , Switzerland
| | - Ulf Skyllberg
- Department of Forest Ecology and Management , Swedish University of Agricultural Sciences , 901 83 Umeå , Sweden
| | - Claudia Cosio
- Department F.-A. Forel for environmental and aquatic sciences, Earth and Environmental Sciences, Faculty of Sciences , University of Geneva , CH-1211 Geneva , Switzerland
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17
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Díaz-Jaramillo M, Miglioranza KSB, Carriquiriborde P, Marino D, Pegoraro CN, Valenzuela G, Barra R. Sublethal effects in Perinereis gualpensis (Polychaeta: Nereididae) exposed to mercury-pyrene sediment mixture observed in a multipolluted estuary. ECOTOXICOLOGY (LONDON, ENGLAND) 2017; 26:792-801. [PMID: 28470376 DOI: 10.1007/s10646-017-1810-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/20/2017] [Indexed: 06/07/2023]
Abstract
Sediment-living organisms can be subjected to a multi-pollution condition due to an increase in the diversity of contaminants. Sediment mixtures of Mercury (Hg) and some polycyclic aromatics hydrocarbons like Pyrene (Pyr) are common in heavily industrialized coastal zones. In the present study, greater than (>) and less than (<) probable effect concentration levels (PELs) of Hg and Pyr were assessed using spiked sediments in order to determine combined (Hg + Pyr) effects in uptake, metabolization and oxidative balance in the polychaete Perinereis gualpensis at short and medium-term exposure. Hg + Pyr significantly influenced the uptake/kinetics of Hg and Pyr metabolite 1-OH-pyrene in polychaete tissues during the exposure time compared with separate treatments of each analyte (p < 0.05). Both the Hg-only and Pyr-only exposures significantly influenced both enzymatic and non-enzymatic responses respect to control groups (p < 0.05). The Hg-only treatment showed the worst scenario related to the activation and subsequent inhibition of glutathione S- transferase (GST) and peroxidase (GPx) activities, high levels of Thiol-groups (SH-groups), low antioxidant capacity (ACAP) and enhanced lipid peroxidation (TBARS) in the last days of exposure (p < 0.05). In contrast, ragworms exposed to Hg + Pyr showed a significant increase in both enzymatic and non-enzymatic activity during the first days of exposure and the absence of lipid peroxidation during the whole experiment. Our results suggest different oxidative stress scenarios in P. gualpensis when exposed to >PEL Hg concentration with <PEL Pyr in sediments. Results also reveal the importance of the exposure time, endpoints involved as well as of the contaminant monitoring during the whole experiments in assessing the interactive effects of the contaminant mixture.
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Affiliation(s)
- M Díaz-Jaramillo
- Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales & Centro EULA-Chile, Universidad de Concepción, Concepcion, Chile.
- IIMyC, UNMdP, CONICET, Laboratorio de Ecotoxicología y Contaminación Ambiental, Funes 3350 (B7602AYL), Mar del Plata, 7600, Argentina.
| | - K S B Miglioranza
- IIMyC, UNMdP, CONICET, Laboratorio de Ecotoxicología y Contaminación Ambiental, Funes 3350 (B7602AYL), Mar del Plata, 7600, Argentina
| | - P Carriquiriborde
- Centro de Investigaciones del Medio Ambiente, Facultad de Ciencias Exactas, Universidad Nacional de La Plata- CONICET, La Plata, Argentina
| | - D Marino
- Centro de Investigaciones del Medio Ambiente, Facultad de Ciencias Exactas, Universidad Nacional de La Plata- CONICET, La Plata, Argentina
| | - C N Pegoraro
- Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata-CONICET, Mar del Plata, Argentina
| | - G Valenzuela
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - R Barra
- Departamento de Sistemas Acuáticos, Facultad de Ciencias Ambientales & Centro EULA-Chile, Universidad de Concepción, Concepcion, Chile
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18
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Wang Y, Zhang C, Zheng Y, Ge Y. Phytochelatin synthesis in Dunaliella salina induced by arsenite and arsenate under various phosphate regimes. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 136:150-160. [PMID: 27865115 DOI: 10.1016/j.ecoenv.2016.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/04/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
This study investigated the dynamic variations in thiol compounds, including cysteine (Cys), glutathione (GSH), and phytochelatins (PCs), in Dunaliella salina samples exposed to arsenite [As(III)] and arsenate [As(V)] under various phosphate (PO43-) regimes. Our results showed that GSH was the major non-protein sulfhydryl compound in D. salina cells. As(III) and As(V) induced PC syntheses in D. salina. PC2, PC3, and PC4 were all found in algal cells; the PC concentrations decreased gradually while exposed to As for 3 d. The synthesis of PC2-3 was significantly affected by As(III) and As(V) concentrations in the cultures. More PCs were detected in the As(V)-treated algal cells compared with the As(III) treatment. PC levels increased with As(III)/As(V) amount in the medium, but remained stable after 112μgL-1 As(V) exposure. In contrast, significant (p<0.001) positive correlations were observed between PC synthesis and intracellular As(III) content or As accumulation in As(III)-treated algal cells during the 72-h exposure. PO43- had a significant influence on the PC synthesis in algal cells, irrespective of the As-treated species. Reductions in As uptake and subsequent PC synthesis by D. salina were observed as the PO43- concentration in the growth medium increased. L-Buthionine sulfoximine (BSO) differentially influenced PC synthesis in As-treated D. salina under different extracellular PO43- regimes. Overall, our data demonstrated that the production of GSH and PCs was affected by PO43- and that these thiols played an important role in As detoxification by D. salina.
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Affiliation(s)
- Ya Wang
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Chunhua Zhang
- Demonstration Laboratory of Element and Life Science Research, Laboratory Centre of Life Science, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanheng Zheng
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Ying Ge
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
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Quantitative Relationship between Cadmium Uptake and the Kinetics of Phytochelatin Induction by Cadmium in a Marine Diatom. Sci Rep 2016; 6:35935. [PMID: 27779209 PMCID: PMC5078787 DOI: 10.1038/srep35935] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 10/06/2016] [Indexed: 11/28/2022] Open
Abstract
Heavy metals activate the synthesis of phytochelatins (PCs), while the induced PCs might affect metal uptake via chelating intracellular free metals. However, the relationship of PCs to metal uptake is poorly understood. In this study, we examined the kinetics of cadmium (Cd) accumulation and the synthesis of PCs in a marine diatom, Thalassiosira weissflogii, under different irradiance levels. Irradiance alone could not change the concentrations of PCs in the Cd-free treatments, while higher irradiance accelerated the induction of intracellular PCs at the same [Cd2+] level. PC-SH (2 × PC2 + 3 × PC3 + 4 × PC4) was bound with Cd at a stoichiometric ratio of 2 to 49 in our short-term uptake experiments, indicating that PC induction is sufficient to serve as the first line of defense against Cd stress. A positive linear correlation between the induction rate of PCs and the Cd uptake rate was observed, while the ratio of the PC content to intracellular Cd varied greatly when the irradiance was increased several fold. Because metal uptake has been successfully used in predicting acute metal toxicity, our findings are helpful for understanding the role of PCs in metal detoxification and developing PCs as biomarkers for metal sensitivity.
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Bravo AG, Le Faucheur S, Monperrus M, Amouroux D, Slaveykova VI. Species-specific isotope tracers to study the accumulation and biotransformation of mixtures of inorganic and methyl mercury by the microalga Chlamydomonas reinhardtii. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 192:212-215. [PMID: 24932531 DOI: 10.1016/j.envpol.2014.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/30/2014] [Accepted: 05/09/2014] [Indexed: 06/03/2023]
Abstract
The present study demonstrates that species-specific isotope tracing is an useful tool to precisely measure Hg accumulation and transformations capabilities of living organisms at concentrations naturally encountered in the environment. To that end, a phytoplanktonic green alga Chlamydomonas reinhardtii Dangeard (Chlamydomonadales, Chlorophyceae) was exposed to mixtures of (199)-isotopically enriched inorganic mercury ((199)IHg) and of (201)-isotopically enriched monomethylmercury ((201)CH3Hg) at a concentration range between less than 1 pM to 4 nM. Additionally, one exposure concentration of both mercury species was also studied separately to evaluate possible interactive effects. No difference in the intracellular contents was observed for algae exposed to (199)IHg and (201)CH3Hg alone or in their mixture, suggesting similar accumulation capacity for both species at the studied concentrations. Demethylation of (201)CH3Hg was observed at the highest exposure concentrations, whereas no methylation was detected.
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Affiliation(s)
- Andrea Garcia Bravo
- University of Geneva, Earth and Environment Sciences, Institute F.-A. Forel, 10 route de Suisse, CP 416, CH-1290 Versoix, Switzerland.
| | - Séverine Le Faucheur
- University of Geneva, Earth and Environment Sciences, Institute F.-A. Forel, 10 route de Suisse, CP 416, CH-1290 Versoix, Switzerland
| | - Mathilde Monperrus
- Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux, IPREM UMR 5254 CNRS - Université de Pau et des Pays de l'Adour, Hélioparc, 2, Avenue Pierre Angot, 64053 Pau Cedex, France
| | - David Amouroux
- Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Matériaux, IPREM UMR 5254 CNRS - Université de Pau et des Pays de l'Adour, Hélioparc, 2, Avenue Pierre Angot, 64053 Pau Cedex, France
| | - Vera I Slaveykova
- University of Geneva, Earth and Environment Sciences, Institute F.-A. Forel, 10 route de Suisse, CP 416, CH-1290 Versoix, Switzerland.
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Wang Z, Luo Z, Yan C, Che F, Yan Y. Arsenic uptake and depuration kinetics in Microcystis aeruginosa under different phosphate regimes. JOURNAL OF HAZARDOUS MATERIALS 2014; 276:393-399. [PMID: 24922097 DOI: 10.1016/j.jhazmat.2014.05.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/12/2014] [Accepted: 05/15/2014] [Indexed: 06/03/2023]
Abstract
Strategies used by Microcystis aeruginosa, bloom-forming cyanobacteria, for potential inorganic arsenic (arsenate and arsenite) uptake, and depuration kinetics under phosphate-enriched (+P) and depleted (-P) treatments were examined via short- and long-term experiments. Phosphate depletion improved arsenate or arsenite uptake rate constants. M. aeruginosa arsenite influx occurred considerably faster than arsenate influx under +P or -P treatments. Different phosphate regimes yielded significant impacts on long-term but not on short-term arsenic (As) uptake. In addition, considerable differences were observed in short-term As efflux between live and dead cells after arsenate or arsenite pre-exposure. Arsenic depuration rates in live M. aeruginosa cells were affected not only by accumulation rates of different As inorganic species but also by phosphate concentrations in tested media, which was inferred from estimated kinetic parameters. Specifically, +P was clearly found to inhibit As efflux after live M. aeruginosa cells were pre-exposed to As(V). Efflux was higher for dead cells no matter the inorganic As species involved. Owing to higher As uptake and depuration rates under -P treatments, P deficiency will considerably accelerate As uptake and efflux processes in aquatic environments.
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Affiliation(s)
- Zhenhong Wang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000, China
| | - Zhuanxi Luo
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Changzhou Yan
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Feifei Che
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Yameng Yan
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
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Le Faucheur S, Campbell PGC, Fortin C, Slaveykova VI. Interactions between mercury and phytoplankton: speciation, bioavailability, and internal handling. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2014; 33:1211-1224. [PMID: 24127330 DOI: 10.1002/etc.2424] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 06/11/2013] [Accepted: 10/03/2013] [Indexed: 06/02/2023]
Abstract
The present review describes and discusses key interactions between mercury (Hg) and phytoplankton to highlight the role of phytoplankton in the biogeochemical cycle of Hg and to understand direct or indirect Hg effects on phytoplankton. Phytoplankton are exposed to various Hg species in surface waters. Through Hg uptake, phytoplankton affect the concentration, speciation, and fate of Hg in aquatic systems. The mechanisms by which phytoplankton take up Hg are still not well known, but several studies have suggested that both facilitated transport and passive diffusion could be involved. Once internalized, Hg will impact several physiological processes, including photosynthesis. To counteract these negative effects, phytoplankton have developed several detoxification strategies, such as the reduction of Hg to elemental Hg or its sequestration by intracellular ligands. Based on the toxicological studies performed so far in the laboratory, Hg is unlikely to be toxic to phytoplankton when they are exposed to environmentally relevant Hg concentrations. However, this statement should be taken with caution because questions remain as to which Hg species control Hg bioavailability and about Hg uptake mechanisms. Finally, phytoplankton are primary producers, and accumulated Hg will be transferred to higher consumers. Phytoplankton are a key component in aquatic systems, and their interactions with Hg need to be further studied to fully comprehend the biogeochemical cycle of Hg and the impact of this ubiquitous metal on ecosystems.
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Affiliation(s)
- Séverine Le Faucheur
- Institute F.-A. Forel, Earth and Environmental Sciences, Faculty of Sciences, University of Geneva, Versoix, Switzerland
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Bouchet S, Björn E. Analytical developments for the determination of monomethylmercury complexes with low molecular mass thiols by reverse phase liquid chromatography hyphenated to inductively coupled plasma mass spectrometry. J Chromatogr A 2014; 1339:50-8. [DOI: 10.1016/j.chroma.2014.02.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/12/2014] [Accepted: 02/16/2014] [Indexed: 11/29/2022]
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Wu Y, Wang WX. Differential acclimation of a marine diatom to inorganic mercury and methylmercury exposure. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 138-139:52-59. [PMID: 23707793 DOI: 10.1016/j.aquatox.2013.04.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 04/21/2013] [Accepted: 04/24/2013] [Indexed: 06/02/2023]
Abstract
Aquatic organisms originating from metal polluted water may exhibit differences in their sensitivity to metals, but the underlying physiological mechanisms resulting in such responses have not been well reported. In the present study, a marine diatom Thalassiosira weissflogii was chronically exposed to different inorganic mercury (Hg(II), 0.5 and 5 μg Hg/L) or methylmercury (MeHg, 0.02 and 0.4 μg Hg/L) concentrations for over 18 generations. We then quantified the changes in the Hg(II) or MeHg sensitivity, Hg accumulation, subcellular distribution, as well as thiol compound induction in the diatoms. We found an unchanged tolerance to Hg(II) but an enhanced tolerance to MeHg in the preconditioned T. weissflogii. The underlying mechanisms may be related to the changes in cellular mercury accumulation and the detoxification ability of the cells. Specifically, exposure to high-Hg(II) led to increased metal distribution in cellular debris fraction, as well as the induction of a variety of non-protein thiol compounds, but the uptake kinetics was not significantly modified by Hg(II) exposure. Instead, exposure to high-MeHg decreased the mercury uptake rate along with the synthesis of glutathione (GSH) and (γ-EC)₂-Gly (PC₂). All these responses contributed to the different tolerance developments between Hg(II) and MeHg. This study suggests that moderation of Hg bioavailability was probably more important than internal detoxification in the development of Hg acclimation in marine diatoms.
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Affiliation(s)
- Yun Wu
- Division of Life Science, The Hong Kong University of Science and Technology-HKUST, Clear Water Bay, Kowloon, Hong Kong
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