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Yang X, Kong L, Wang Y, Su J, Shen W. Methane control of cadmium tolerance in alfalfa roots requires hydrogen sulfide. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 284:117123. [PMID: 33906033 DOI: 10.1016/j.envpol.2021.117123] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 03/24/2021] [Accepted: 04/08/2021] [Indexed: 05/28/2023]
Abstract
Hydrogen sulfide (H2S) is well known as a gaseous signal in response to heavy metal stress, while methane (CH4), the most prevalent greenhouse gas, confers cadmium (Cd) tolerance. In this report, the causal link between CH4 and H2S controlling Cd tolerance in alfalfa (Medicago sativa) plants was assessed. Our results observed that the administration of CH4 not only intensifies H2S metabolism, but also attenuates Cd-triggered growth inhibition in alfalfa seedlings, which were parallel to the alleviated roles in the redox imbalance and cell death in root tissues. Above results were not observed in roots after the removal of endogenous H2S, either in the presence of either hypotaurine (HT; a H2S scavenger) or DL-propargylglycine (PAG; a H2S biosynthesis inhibitor). Using in situ noninvasive microtest technology (NMT) and inductively coupled plasma mass spectroscopy (ICP-MS), subsequent results confirmed the participation of H2S in CH4-inhibited Cd influx and accumulation in roots, which could be explained by reestablishing glutathione (GSH) pool (reduced/oxidized GSH and homoglutathione) homeostasis and promoting antioxidant defence. Overall, our results clearly revealed that H2S operates downstream of CH4 enhancing tolerance against Cd stress, which are significant for both fundamental and applied plant biology.
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Affiliation(s)
- Xinghao Yang
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Lingshuai Kong
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Yueqiao Wang
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Jiuchang Su
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Wenbiao Shen
- College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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2
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Pons ML, Collin B, Doelsch E, Chaurand P, Fehlauer T, Levard C, Keller C, Rose J. X-ray absorption spectroscopy evidence of sulfur-bound cadmium in the Cd-hyperaccumulator Solanum nigrum and the non-accumulator Solanum melongena. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 279:116897. [PMID: 33774364 DOI: 10.1016/j.envpol.2021.116897] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/24/2021] [Accepted: 03/02/2021] [Indexed: 06/12/2023]
Abstract
It has been proposed that non-protein thiols and organic acids play a major role in cadmium phytoavailability and distribution in plants. In the Cd-hyperaccumulator Solanum nigrum and non-accumulator Solanum melongena, the role of these organic ligands in the accumulation and detoxification mechanisms of Cd are debated. In this study, we used X-ray absorption spectroscopy to investigate Cd speciation in these plants (roots, stem, leaves) and in the soils used for their culture to unravel the plants responses to Cd exposure. The results show that Cd in the 100 mg kg-1 Cd-doped clayey loam soil is sorbed onto iron oxyhydroxides. In both S. nigrum and S. melongena, Cd in roots and fresh leaves is mainly bound to thiol ligands, with a small contribution of inorganic S ligands in S. nigrum leaves. We interpret the Cd binding to sulfur ligands as detoxification mechanisms, possibly involving the sequestration of Cd complexed with glutathione or phytochelatins in the plant vacuoles. In the stems, results show an increase binding of Cd to -O ligands (>50% for S. nigrum). We suggest that Cd is partly complexed by organic acids for transportation in the sap.
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Affiliation(s)
- Marie-Laure Pons
- Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE UMR 7330, Aix en Provence, France.
| | - Blanche Collin
- Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE UMR 7330, Aix en Provence, France
| | - Emmanuel Doelsch
- CIRAD, UPR Recyclage et Risque, F-34398, Montpellier, France; Recyclage et Risque, Univ Montpellier, CIRAD, Montpellier, France
| | - Perrine Chaurand
- Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE UMR 7330, Aix en Provence, France
| | - Till Fehlauer
- Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE UMR 7330, Aix en Provence, France
| | - Clément Levard
- Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE UMR 7330, Aix en Provence, France
| | - Catherine Keller
- Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE UMR 7330, Aix en Provence, France
| | - Jérôme Rose
- Aix Marseille Univ, CNRS, IRD, INRAE, Coll France, CEREGE UMR 7330, Aix en Provence, France
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3
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Wątły J, Łuczkowski M, Padjasek M, Krężel A. Phytochelatins as a Dynamic System for Cd(II) Buffering from the Micro- to Femtomolar Range. Inorg Chem 2021; 60:4657-4675. [PMID: 33736430 PMCID: PMC8041291 DOI: 10.1021/acs.inorgchem.0c03639] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Indexed: 01/30/2023]
Abstract
Phytochelatins (PCs) are short Cys-rich peptides with repeating γ-Glu-Cys motifs found in plants, algae, certain fungi, and worms. Their biosynthesis has been found to be induced by heavy metals-both biogenic and toxic. Among all metal inducers, Cd(II) has been the most explored from a biological and chemical point of view. Although Cd(II)-induced PC biosynthesis has been widely examined, still little is known about the structure of Cd(II) complexes and their thermodynamic stability. Here, we systematically investigated glutathione (GSH) and PC2-PC6 systems, with regard to their complex stoichiometries and spectroscopic and thermodynamic properties. We paid special attention to the determination of stability constants using several complementary techniques. All peptides form CdL complexes, but CdL2 was found for GSH, PC2, and partially for PC3. Moreover, binuclear species CdxLy were identified for the series PC3-PC6 in an excess of Cd(II). Potentiometric and competition spectroscopic studies showed that the affinity of Cd(II) complexes increases from GSH to PC4 almost linearly from micromolar (log K7.4GSH = 5.93) to the femtomolar range (log K7.4PC4 = 13.39) and additional chain elongation does not increase the stability significantly. Data show that PCs form an efficient system which buffers free Cd(II) ions in the pico- to femtomolar range under cellular conditions, avoiding significant interference with Zn(II) complexes. Our study confirms that the favorable entropy change is the factor governing the elevation of phytochelatins' stability and illuminates the importance of the chelate effect in shifting the free Gibbs energy.
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Affiliation(s)
| | | | - Michał Padjasek
- Department of Chemical Biology, Faculty
of Biotechnology, University of Wrocław, Joliot-Curie 14a, 50-383 Wrocław, Poland
| | - Artur Krężel
- Department of Chemical Biology, Faculty
of Biotechnology, University of Wrocław, Joliot-Curie 14a, 50-383 Wrocław, Poland
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4
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Colzato M, Kamogawa MY, Carvalho HWP, Alleoni LRF, Hesterberg D. Temporal Changes in Cadmium Speciation in Brazilian Soils Evaluated Using Cd LIII-Edge XANES and Chemical Fractionation. JOURNAL OF ENVIRONMENTAL QUALITY 2017; 46:1206-1214. [PMID: 29293850 DOI: 10.2134/jeq2016.08.0316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chemical speciation of soil cadmium (Cd) dictates its mobility and potential toxicity in the environment. Our objective was to compare temporal changes in speciation of Cd(II) reacted with samples from six Brazilian soils having varying Cd(II) sorption capacities. Cadmium L-edge X-ray absorption near edge structure (XANES) analysis showed there were short-term changes in speciation after reaction with 4.45 mmol Cd kg for 0.5 and 6 h. Chemical fractionation evaluated changes in Cd extractability after reaction with 89 μmol Cd kg for up to 4 mo. The XANES spectral fits suggested that Cd(II) bound with organic matter was a dominant species in all samples, along with Cd(II) bound with iron and aluminum oxides or montmorillonite. In several samples, CdCl apparently precipitated from aqueous Cd(II) during drying. The XANES spectral fits typically showed <25% change in speciation between 0.5 and 6 h of reaction, and chemical fractionation showed significant ( < 0.05) temporal changes in Cd extractability over time in two samples. Our results suggest that Cd(II) discharged into these soils, such as that occurring as a release into the environment, would bind with soil organic matter and oxide minerals or remain dissolved, with little change in speciation in the months following release.
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5
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Ye X, Ling T, Xue Y, Xu C, Zhou W, Hu L, Chen J, Shi Z. Thymol Mitigates Cadmium Stress by Regulating Glutathione Levels and Reactive Oxygen Species Homeostasis in Tobacco Seedlings. Molecules 2016; 21:E1339. [PMID: 27754435 PMCID: PMC6273743 DOI: 10.3390/molecules21101339] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/29/2016] [Accepted: 10/01/2016] [Indexed: 12/15/2022] Open
Abstract
Thymol is a famous plant-derived compound that has been widely used in pharmacy due to its antioxidant and antimicrobial properties. However, the modulation of intrinsic plant physiology by thymol remains unclear. It is a significant challenge to confer plant tolerance to Cd (cadmium) stress. In the present study physiological, histochemical, and biochemical methods were applied to investigate thymol-induced Cd tolerance in tobacco (Nicotiana tabacum) seedlings. Thymol was able to alleviate Cd-induced growth inhibition of tobacco seedlings in both dose- and time-dependent manners. Both histochemical detection and in-tube assays suggested that thymol treatment blocked Cd-induced over-generation of reactive oxygen species (ROS), lipid peroxidation, and loss of membrane integrity in both leaves and roots. Thymol decreased Cd-induced cell death that was indicated in vivo by propidium iodide (PI) and trypan blue, respectively. Thymol stimulated glutathione (GSH) biosynthesis by upregulating the expression of γ-glutamylcysteine synthetase 1 (GSH1) in Cd-treated seedlings, which may contribute to the alleviation of Cd-induced oxidative injury. In situ fluorescent detection of intracellular Cd2+ revealed that thymol significantly decreased free Cd2+ in roots, which could be explained by the thymol-stimulated GSH biosynthesis and upregulation of the expression of phyochelatin synthase 1 (PCS1). Taken together, these results suggested that thymol has great potential to trigger plant resistant responses to combat heavy metal toxicity, which may help our understanding of the mechanism for thymol-modulated cell metabolic pathways in response to environmental stimuli.
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Affiliation(s)
- Xiefeng Ye
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China.
| | - Tianxiao Ling
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China.
| | - Yanfeng Xue
- Nanjing Yangzi Modern Agriculture Investment and Development Co. Ltd., Nanjing 211899, China.
| | - Cunfa Xu
- Central Laboratory, Jiangsu Academy of Agricultural Science, Nanjing 210014, China.
| | - Wei Zhou
- Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China.
| | - Liangbin Hu
- Department of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China.
| | - Jian Chen
- Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
- Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Provincial Department of Agriculture and Forestry, Nanjing 210014, China.
| | - Zhiqi Shi
- Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
- Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Provincial Department of Agriculture and Forestry, Nanjing 210014, China.
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6
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Pushie MJ, Pickering I, Korbas M, Hackett MJ, George GN. Elemental and chemically specific X-ray fluorescence imaging of biological systems. Chem Rev 2014; 114:8499-541. [PMID: 25102317 PMCID: PMC4160287 DOI: 10.1021/cr4007297] [Citation(s) in RCA: 192] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Indexed: 12/13/2022]
Affiliation(s)
- M. Jake Pushie
- Molecular
and Environmental Sciences Research Group, Department of Geological
Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
| | - Ingrid
J. Pickering
- Molecular
and Environmental Sciences Research Group, Department of Geological
Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
- Toxicology
Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
- Department
of Chemistry, University of Saskatchewan, Saskatoon, SK S7N 5C9, Canada
| | - Malgorzata Korbas
- Canadian
Light Source Inc., 44
Innovation Boulevard, Saskatoon, SK S7N 2V3, Canada
- Department
of Anatomy and Cell Biology, University
of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Mark J. Hackett
- Molecular
and Environmental Sciences Research Group, Department of Geological
Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
| | - Graham N. George
- Molecular
and Environmental Sciences Research Group, Department of Geological
Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
- Toxicology
Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
- Department
of Chemistry, University of Saskatchewan, Saskatoon, SK S7N 5C9, Canada
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7
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Structural characterization of Cd2+ complexes in solution with DMSA and DMPS. J Inorg Biochem 2014; 136:99-106. [DOI: 10.1016/j.jinorgbio.2013.10.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/17/2013] [Accepted: 10/23/2013] [Indexed: 11/22/2022]
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8
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Collin B, Doelsch E, Keller C, Cazevieille P, Tella M, Chaurand P, Panfili F, Hazemann JL, Meunier JD. Evidence of sulfur-bound reduced copper in bamboo exposed to high silicon and copper concentrations. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 187:22-30. [PMID: 24418975 DOI: 10.1016/j.envpol.2013.12.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 12/13/2013] [Accepted: 12/23/2013] [Indexed: 06/03/2023]
Abstract
We examined copper (Cu) absorption, distribution and toxicity and the role of a silicon (Si) supplementation in the bamboo Phyllostachys fastuosa. Bamboos were maintained in hydroponics for 4 months and submitted to two different Cu (1.5 and 100 μm Cu(2+)) and Si (0 and 1.1 mM) concentrations. Cu and Si partitioning and Cu speciation were investigated by chemical analysis, microscopic and spectroscopic techniques. Copper was present as Cu(I) and Cu(II) depending on plant parts. Bamboo mainly coped with high Cu exposure by: (i) high Cu sequestration in the root (ii) Cu(II) binding to amino and carboxyl ligands in roots, and (iii) Cu(I) complexation with both organic and inorganic sulfur ligands in stems and leaves. Silicon supplementation decreased the visible damage induced by high Cu exposure and modified Cu speciation in the leaves where a higher proportion of Cu was present as inorganic Cu(I)S compounds, which may be less toxic.
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Affiliation(s)
- Blanche Collin
- CEREGE, CNRS, Aix-Marseille Univ., Europôle méditerranéen de l'Arbois, BP 80, 13545 Aix en Provence, France; Département de recherche développement de la société PHYTOREM S.A., Chemin de l'Autodrome, 13140 Miramas, France.
| | - Emmanuel Doelsch
- CIRAD, UPR Recyclage et risque, Avenue Agropolis, F-34398 Montpellier, France.
| | - Catherine Keller
- CEREGE, CNRS, Aix-Marseille Univ., Europôle méditerranéen de l'Arbois, BP 80, 13545 Aix en Provence, France.
| | - Patrick Cazevieille
- CIRAD, UPR Recyclage et risque, Avenue Agropolis, F-34398 Montpellier, France.
| | - Marie Tella
- CIRAD, UPR Recyclage et risque, Avenue Agropolis, F-34398 Montpellier, France.
| | - Perrine Chaurand
- CEREGE, CNRS, Aix-Marseille Univ., Europôle méditerranéen de l'Arbois, BP 80, 13545 Aix en Provence, France.
| | - Frédéric Panfili
- Département de recherche développement de la société PHYTOREM S.A., Chemin de l'Autodrome, 13140 Miramas, France.
| | - Jean-Louis Hazemann
- Institut Néel, CNRS and Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9, France.
| | - Jean-Dominique Meunier
- CEREGE, CNRS, Aix-Marseille Univ., Europôle méditerranéen de l'Arbois, BP 80, 13545 Aix en Provence, France.
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9
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Parsons JG, Dokken KM, McClure J, Gardea-Torresdey JL. FTIR, XAS, and XRD study of cadmium complexes with l-cysteine. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.04.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Jalilehvand F, Amini Z, Parmar K. Cadmium(II) complex formation with selenourea and thiourea in solution: an XAS and 113Cd NMR study. Inorg Chem 2012; 51:10619-30. [PMID: 23016594 PMCID: PMC3498765 DOI: 10.1021/ic300852t] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The complexes formed in methanol solutions of Cd(CF(3)SO(3))(2) with selenourea (SeU) or thiourea (TU), for thiourea also in aqueous solution, were studied by combining (113)Cd NMR and X-ray absorption spectroscopy. At low temperature (~200 K), distinct (113)Cd NMR signals were observed, corresponding to CdL(n)(2+) species (n = 0-4, L = TU or SeU) in slow ligand exchange. Peak integrals were used to obtain the speciation in the methanol solutions, allowing stability constants to be estimated. For cadmium(II) complexes with thione (C═S) or selone (C═Se) groups coordinated in Cd(S/Se)O(5) or Cd(S/Se)(2)O(4) (O from MeOH or CF(3)SO(3)(-)) environments, the (113)Cd chemical shifts were quite similar, within 93-97 ppm and 189-193 ppm, respectively. However, the difference in the chemical shift for the Cd(SeU)(4)(2+) (578 pm) and Cd(TU)(4)(2+) (526 ppm) species, with CdSe(4) and CdS(4) coordination, respectively, shows less chemical shielding for the coordinated Se atoms than for S, in contrast to the common trend with increasing shielding in the following order: O > N > Se > S. In solutions dominated by mono- and tetra-thiourea/selenourea complexes, their coordination and bond distances could be evaluated by Cd K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy. At ~200 K and high excess of thiourea, a minor amount (up to ~30%) of [Cd(TU)(5-6)](2+) species was detected by an upfield shift of the (113)Cd NMR signal (up to 423 ppm) and an amplitude reduction of the EXAFS oscillation. The amount was estimated by fitting linear combinations of simulated EXAFS spectra for [Cd(TU)(4)](2+) and [Cd(TU)(6)](2+) complexes. At room temperature, [Cd(TU)(4)](2+) was the highest complex formed, also in aqueous solution. Cd L(3)-edge X-ray absorption near edge structure (XANES) spectra of cadmium(II) thiourea solutions in methanol were used to follow changes in the CdS(x)O(y) coordination. The correlations found from the current and previous studies between (113)Cd NMR chemical shifts and different Cd(II) coordination environments are generally useful for evaluating cadmium coordination to thione-containing or Se-donor ligands in biochemical systems or for monitoring speciation in solution.
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Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary, Calgary, AB, Canada T2N 1N4.
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11
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Siebers N, Kruse J, Eckhardt KU, Hu Y, Leinweber P. Solid-phase cadmium speciation in soil using L3-edge XANES spectroscopy with partial least-squares regression. JOURNAL OF SYNCHROTRON RADIATION 2012; 19:579-585. [PMID: 22713893 DOI: 10.1107/s0909049512021371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 05/10/2012] [Indexed: 06/01/2023]
Abstract
Cadmium (Cd) has a high toxicity and resolving its speciation in soil is challenging but essential for estimating the environmental risk. In this study partial least-square (PLS) regression was tested for its capability to deconvolute Cd L(3)-edge X-ray absorption near-edge structure (XANES) spectra of multi-compound mixtures. For this, a library of Cd reference compound spectra and a spectrum of a soil sample were acquired. A good coefficient of determination (R(2)) of Cd compounds in mixtures was obtained for the PLS model using binary and ternary mixtures of various Cd reference compounds proving the validity of this approach. In order to describe complex systems like soil, multi-compound mixtures of a variety of Cd compounds must be included in the PLS model. The obtained PLS regression model was then applied to a highly Cd-contaminated soil revealing Cd(3)(PO(4))(2) (36.1%), Cd(NO(3))(2)·4H(2)O (24.5%), Cd(OH)(2) (21.7%), CdCO(3) (17.1%) and CdCl(2) (0.4%). These preliminary results proved that PLS regression is a promising approach for a direct determination of Cd speciation in the solid phase of a soil sample.
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Affiliation(s)
- Nina Siebers
- Institute for Land Use, University of Rostock, Justus-von-Liebig-Weg 6, 18051 Rostock, Germany
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12
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Pei KL, Sooriyaarachchi M, Sherrell DA, George GN, Gailer J. Probing the coordination behavior of Hg2+, CH3Hg+, and Cd2+ towards mixtures of two biological thiols by HPLC-ICP-AES. J Inorg Biochem 2011; 105:375-81. [PMID: 21421124 DOI: 10.1016/j.jinorgbio.2010.11.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 11/16/2010] [Accepted: 11/26/2010] [Indexed: 11/30/2022]
Affiliation(s)
- Katie L Pei
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada
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13
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Liu C, Bai R. Extended study of DETA-functionalized PGMA adsorbent in the selective adsorption behaviors and mechanisms for heavy metal ions of Cu, Co, Ni, Zn, and Cd. J Colloid Interface Sci 2010; 350:282-9. [DOI: 10.1016/j.jcis.2010.04.084] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 04/25/2010] [Accepted: 04/28/2010] [Indexed: 11/28/2022]
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14
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Jalilehvand F, Leung BO, Mah V. Cadmium(II) complex formation with cysteine and penicillamine. Inorg Chem 2010; 48:5758-71. [PMID: 19469490 DOI: 10.1021/ic802278r] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The complex formation between cadmium(II) and the ligands cysteine (H(2)Cys) and penicillamine (H(2)Pen = 3,3'-dimethylcysteine) in aqueous solutions, having C(Cd(II)) approximately 0.1 mol dm(-3) and C(H(2)L) = 0.2-2 mol dm(-3), was studied at pH = 7.5 and 11.0 by means of (113)Cd NMR and Cd K- and L(3)-edge X-ray absorption spectroscopy. For all cadmium(II)-cysteine molar ratios, the mean Cd-S and Cd-(N/O) bond distances were found in the ranges 2.52-2.54 and 2.27-2.35 A, respectively. The corresponding cadmium(II)-penicillamine complexes showed slightly shorter Cd-S bonds, 2.50-2.53 A, but with the Cd-(N/O) bond distances in a similar wide range, 2.28-2.33 A. For the molar ratio C(H(2)L)/C(Cd(II)) = 2, the (113)Cd chemical shifts, in the range 509-527 ppm at both pH values, indicated complexes with distorted tetrahedral CdS(2)N(N/O) coordination geometry. With a large excess of cysteine (molar ratios C(H(2)Cys)/C(Cd(II)) >or= 10), complexes with CdS(4) coordination geometry dominate, consistent with the (113)Cd NMR chemical shifts, delta approximately 680 ppm at pH 7.5 and 636-658 ppm at pH 11.0, and their mean Cd-S distances were 2.53 +/- 0.02 A. At pH 7.5, the complexes are almost exclusively sulfur-coordinated as [Cd(S-cysteinate)(4)](n-), while at higher pH, the deprotonation of the amine groups promotes chelate formation. At pH 11.0, a minor amount of the [Cd(Cys)(3)](4-) complex with CdS(3)N coordination is formed. For the corresponding penicillamine solutions with molar ratios C(H(2)Pen)/C(Cd(II)) >or= 10, the (113)Cd NMR chemical shifts, delta approximately 600 ppm at pH 7.5 and 578 ppm at pH 11.0, together with the average bond distances, Cd-S 2.53 +/- 0.02 A and Cd-(N/O) 2.30-2.33 A, indicate that [Cd(penicillaminate)(3)](n-) complexes with chelating CdS(3)(N/O) coordination dominate already at pH 7.5 and become mixed with CdS(2)N(N/O) complexes at pH 11.0. The present study reveals differences between cysteine and penicillamine as ligands to the cadmium(II) ion that can explain why cysteine-rich metallothionines are capable of capturing cadmium(II) ions, while penicillamine, clinically useful for treating the toxic effects of mercury(II) and lead(II) exposure, is not efficient against cadmium(II) poisoning.
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Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary, Calgary, AB, Canada T2N 1N4.
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15
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Collins RN, Bakkaus E, Carrière M, Khodja H, Proux O, Morel JL, Gouget B. Uptake, localization, and speciation of cobalt in Triticum aestivum L. (wheat) and Lycopersicon esculentum M. (tomato). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:2904-2910. [PMID: 20345097 DOI: 10.1021/es903485h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The root-to-shoot transfer, localization, and chemical speciation of Co were investigated in a monocotyledon (Triticum aestivum L., wheat) and a dicotyledon (Lycopersicon esculentum M., tomato) plant species grown in nutrient solution at low (5 muM) and high (20 muM) Co(II) concentrations. Cobalt was measured in the roots and shoots by inductively coupled plasma-mass spectrometry. X-ray absorption spectroscopy measurements were used to identify the chemical structure of Co within the plants and Co distribution in the leaves was determined by micro-PIXE (particle induced X-ray emission). Although the root-to-shoot transport was higher for tomato plants exposed to excess Co, both plants appeared as excluders. The oxidation state of Co(II) was not transformed by either plant in the roots or shoots and Co appeared to be present as Co(II) in a complex with carboxylate containing organic acids. Cobalt was also essentially located in the vascular system of both plant species indicating that neither responded to Co toxicity via sequestration in epidermal or trichome tissues as has been observed for other metals in metal hyperaccumulating plants.
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Affiliation(s)
- Richard N Collins
- UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
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16
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Mah V, Jalilehvand F. Cadmium(II) complex formation with glutathione. J Biol Inorg Chem 2009; 15:441-58. [PMID: 20035360 DOI: 10.1007/s00775-009-0616-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 12/04/2009] [Indexed: 11/24/2022]
Abstract
Complex formation between heavy metal ions and glutathione (GSH) is considered as the initial step in many detoxification processes in living organisms. In this study the structure and coordination between the cadmium(II) ion and GSH were investigated in aqueous solutions (pH 7.5 and 11.0) and in the solid state, using a combination of spectroscopic techniques. The similarity of the Cd K-edge and L(3)-edge X-ray absorption spectra of the solid compound [Cd(GS)(GSH)]ClO(4).3H(2)O, precipitating at pH 3.0, with the previously studied cysteine compound {Cd(HCys)(2).H(2)O}(2).H(3)O(+).ClO(4) (-) corresponds to Cd(S-GS)(3)O (dominating) and Cd(S-GS)(4) four-coordination within oligomeric complexes with mean bond distances of 2.51 +/- 0.02 A for Cd-S and 2.24 +/- 0.04 A for Cd-O. For cadmium(II) solutions (C (Cd(II)) approximately 0.05 M) at pH 7.5 with moderate excess of GSH (C (GSH)/C (Cd(II)) = 3.0-5.0), a mix of Cd(S-GS)(3)O (dominating) and Cd(S-GS)(4) species is consistent with the broad (113)Cd NMR resonances in the range 632-658 ppm. In alkaline solutions (pH 11.0 and C (GSH)/C (Cd(II)) = 2.0 or 3.0), two distinct peaks at 322 and 674 ppm are obtained. The first peak indicates six-coordinated mononuclear and dinuclear complexes with CdS(2)N(2)(N/O)(2) and CdSN(3)O(2) coordination in fast exchange, whereas the second corresponds to Cd(S-GS)(4) sites. At high ligand excess the tetrathiolate complex, Cd(S-GS)(4), characterized by a sharp delta((113)Cd) NMR signal at 677 ppm, predominates. The average Cd-S distance, obtained from the X-ray absorption spectra, varied within a narrow range, 2.49-2.53 A, for all solutions (pH 7.5 and 11.0) regardless of the coordination geometry.
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Affiliation(s)
- Vicky Mah
- Department of Chemistry, University of Calgary, Calgary, AB, T2N 1N4, Canada
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Castillo-Michel HA, Hernandez N, Martinez-Martinez A, Parsons JG, Peralta-Videa JR, Gardea-Torresdey JL. Coordination and speciation of cadmium in corn seedlings and its effects on macro- and micronutrients uptake. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2009; 47:608-614. [PMID: 19285423 DOI: 10.1016/j.plaphy.2009.02.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 01/13/2009] [Accepted: 02/16/2009] [Indexed: 05/27/2023]
Abstract
The effect of cadmium (Cd) on both the absorption of important nutrients and the synthesis of low molecular weight thiols (LMWTs) was investigated in corn plants. The inductively coupled plasma-optical emission spectroscopy results demonstrated that the concentration of Cd in tissues (mainly in roots) increased as the concentration in the medium increased. In addition, the concentration of phosphorus increased in roots of Cd treated plants but remained at normal concentration in shoots. On the other hand, the uptake of sulfur (S) followed a similar trend as the Cd uptake. The concentration of S and the production of LMWT were found to increase significantly upon exposure to Cd. The results of the X-ray absorption spectroscopy analyses indicated that Cd within tissues was bound to S ligands with interatomic distances of 2.51-2.52 A. These results confirm a strong linkage between S uptake and the production of LMWT upon exposure to Cd.
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Affiliation(s)
- Hiram A Castillo-Michel
- Department of Environmental Science and Engineering Ph.D. Program, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
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18
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Jalilehvand F, Mah V, Leung BO, Mink J, Bernard GM, Hajba L. Cadmium(II) cysteine complexes in the solid state: a multispectroscopic study. Inorg Chem 2009; 48:4219-30. [PMID: 19351134 DOI: 10.1021/ic900145n] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cadmium(II) cysteinate compounds have recently been recognized to provide an environmentally friendly route for the production of CdS nanoparticles, used in semiconductors. In this article, we have studied the coordination for two cadmium(II) cysteinates, Cd(HCys)(2) x H(2)O (1) and {Cd(HCys)(2) x H(2)O}(2) x H(3)O(+)ClO(4)(-) (2), by means of vibrational (Raman and IR absorption), solid-state NMR ((113)Cd and (13)C), and Cd K- and L(3)-edge X-ray absorption spectroscopy. Indistinguishable Cd K-edge extended X-ray absorption fine structure (EXAFS) and Cd L(3)-edge X-ray absorption near edge structure (XANES) spectra were obtained for the two compounds, showing similar local structure around the cadmium(II) ions. The vibrational spectra show that the cysteine amine group is protonated (NH(3)(+)) and not involved in bonding. The (113)Cd solid-state cross-polarization magic angle spinning NMR spectra showed a broad signal in the approximately 500-700 ppm range, with the peak maximum at about 650 ppm, indicating three to four coordinated thiolate groups. Careful analyses of low-frequency Raman and far-IR spectra revealed bridging and terminal Cd-S vibrational bands. The average Cd-S distance of 2.52 +/- 0.02 A that constantly emerged from least-squares curve-fitting of the EXAFS spectra is consistent with CdS(4) and CdS(3)O coordination. Both structural models yielded reasonable values for the refined parameters, with a slightly better fit for the CdS(3)O configuration, for which the Cd-O distance of 2.27 +/- 0.04 A was obtained. The Cd L(3)-edge XANES spectra of 1 and 2 resembled that of the CdS(3)O model compound and showed that the coordination around Cd(II) ions in 1 and 2 cannot be exclusively CdS(4). The small separation of 176 cm(-1) between the infrared symmetric and antisymmetric COO(-) stretching modes indicates monodentate or strongly asymmetrical bidentate coordination of a cysteine carboxylate group in the CdS(3)O units. The combined results are consistent with a "cyclic/cage" type of structure for both the amorphous solids 1 and 2, composed of CdS(4) and CdS(3)O units with single thiolate (Cd-S-Cd) bridges, although a minor amount of cadmium(II) sites with CdS(3)O(2-3) and CdS(4)O coordination geometries cannot be ruled out.
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Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary, Calgary, AB, Canada T2N 1N4.
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19
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Van der Snickt G, Dik J, Cotte M, Janssens K, Jaroszewicz J, De Nolf W, Groenewegen J, Van der Loeff L. Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques. Anal Chem 2009; 81:2600-10. [PMID: 19278249 DOI: 10.1021/ac802518z] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
On several paintings of James Ensor (1860-1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (mu-XANES) experiments show that sulfur, originally present in sulfidic form (S(2-)), is oxidized during the transformation to the sulfate form (S(6+)). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO(4).2H(2)O) and ammonium cadmium sulfate [(NH(4))(2)Cd(SO(4))(2)] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1-2 microm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR micro-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators.
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Affiliation(s)
- Geert Van der Snickt
- Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
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Chen L, Yang L, Wang Q. In vivo phytochelatins and Hg–phytochelatin complexes in Hg-stressed Brassica chinensis L. Metallomics 2009. [DOI: 10.1039/b815477e] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Reisinger S, Schiavon M, Terry N, Pilon-Smits EAH. Heavy metal tolerance and accumulation in Indian mustard (Brassica juncea L.) expressing bacterial gamma-glutamylcysteine synthetase or glutathione synthetase. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2008; 10:440-54. [PMID: 19260225 DOI: 10.1080/15226510802100630] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The overexpression of either gamma-glutamylcysteine synthetase (gamma-ECS) or glutathione synthetase (GS) in Brassica juncea transgenics was shown previously to result in higher accumulation of glutathione (GSH) and phytochelatins (PCs), as well as enhanced Cd tolerance and accumulation. The present study was aimed at analyzing the effects of gamma-ECS or GS overexpression on tolerance to and accumulation of other metal/loids supplied individually in agar medium (seedlings) or in hydroponics (mature plants). Also, as pollution in nature generally consists of mixtures of metals, glutamylcysteine synthetase (ECS) and GS seedlings were tested on combinations of metals. Compared to wild-type plants, ECS and GS transgenics exhibited a significantly higher capacity to tolerate and accumulate a variety of metal/loids (particularly As, Cd, and Cr) as well as mixed-metal combinations (As, Cd, Zn/As, Pb, and Zn). This enhanced metal tolerance and accumulation of the ECS and GS transgenics may be attributable to enhanced production of PCs, sustained by a greater availability of GSH as substrate, as suggested by their higher concentrations of GSH, PC2, PC3, and PC4 as compared to wild-type plants. Overexpression of GS and gamma-ECS may represent a promising strategy for the development of plants with an enhanced phytoremediation capacity for mixtures of metals.
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Affiliation(s)
- Sarah Reisinger
- Department of Plant and Microbial Biology, University of California, Berkeley, California, USA
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22
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Mendoza-Cózatl DG, Butko E, Springer F, Torpey JW, Komives EA, Kehr J, Schroeder JI. Identification of high levels of phytochelatins, glutathione and cadmium in the phloem sap of Brassica napus. A role for thiol-peptides in the long-distance transport of cadmium and the effect of cadmium on iron translocation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 54:249-59. [PMID: 18208526 PMCID: PMC2839885 DOI: 10.1111/j.1365-313x.2008.03410.x] [Citation(s) in RCA: 199] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Phytochelatins (PCs) are glutathione-derived peptides that function in heavy metal detoxification in plants and certain fungi. Recent research in Arabidopsis has shown that PCs undergo long-distance transport between roots and shoots. However, it remains unknown which tissues or vascular systems, xylem or phloem, mediate PC translocation and whether PC transport contributes to physiologically relevant long-distance transport of cadmium (Cd) between shoots and roots. To address these questions, xylem and phloem sap were obtained from Brassica napus to quantitatively analyze which thiol species are present in response to Cd exposure. High levels of PCs were identified in the phloem sap within 24 h of Cd exposure using combined mass spectrometry and fluorescence HPLC analyses. Unexpectedly, the concentration of Cd was more than four-fold higher in phloem sap compared to xylem sap. Cadmium exposure dramatically decreased iron levels in xylem and phloem sap whereas other essential heavy metals such as zinc and manganese remained unchanged. Data suggest that Cd inhibits vascular loading of iron but not nicotianamine. The high ratios [PCs]/[Cd] and [glutathione]/[Cd] in the phloem sap suggest that PCs and glutathione (GSH) can function as long-distance carriers of Cd. In contrast, only traces of PCs were detected in xylem sap. Our results suggest that, in addition to directional xylem Cd transport, the phloem is a major vascular system for long-distance source to sink transport of Cd as PC-Cd and glutathione-Cd complexes.
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Affiliation(s)
- David G. Mendoza-Cózatl
- Division of Biological Sciences, Cell and Developmental Biology Section, and Center for Molecular Genetics, University of California, San Diego, La Jolla, CA 92093-0116, USA
| | - Emerald Butko
- Division of Biological Sciences, Cell and Developmental Biology Section, and Center for Molecular Genetics, University of California, San Diego, La Jolla, CA 92093-0116, USA
| | - Franziska Springer
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam OT Golm, Germany
| | - Justin W. Torpey
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378, USA
| | - Elizabeth A. Komives
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378, USA
| | - Julia Kehr
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam OT Golm, Germany
| | - Julian I. Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section, and Center for Molecular Genetics, University of California, San Diego, La Jolla, CA 92093-0116, USA
- For correspondence (fax +1 858 534 7108; )
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Soldatov AV, Smolentsev G, Yalovega G, Chan J, Stillman M. The structure of Cd sites in metallothioneins studied by combination of XAFS and molecular dynamic. Radiat Phys Chem Oxf Engl 1993 2006. [DOI: 10.1016/j.radphyschem.2005.07.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Duncan KER, Ngu TT, Chan J, Salgado MT, Merrifield ME, Stillman MJ. Peptide folding, metal-binding mechanisms, and binding site structures in metallothioneins. Exp Biol Med (Maywood) 2006; 231:1488-99. [PMID: 17018871 DOI: 10.1177/153537020623100907] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This minireview specifically focuses on recent studies carried out on structural aspects of metal-free metallothionein (MT), the mechanism of metal binding for copper and arsenic, structural studies using x-ray absorption spectroscopy and molecular mechanics modeling, and speciation studies of a novel cadmium and arsenic binding algal MT. Molecular mechanics-molecular dynamics calculations of apo-MT show that significant secondary structural features are retained by the polypeptide backbone upon sequential removal of the metal ions, which is stabilized by a possible H-bonding network. In addition, the cysteinyl sulfurs were shown to rotate from within the domain core, where they are found in the metallated state, to the exterior surface of the domain, suggesting an explanation for the rapid metallation reactions that were measured. Mixing Cu6beta-MT with Cd4alpha-MT and Cu6alpha-MT with Cd3beta-MT resulted in redistribution of the metal ions to mixed metal species in each domain; however, the Cu+ ions preferentially coordinated to the beta domain in each case. Reaction of As3+ with the individual metal-free beta and alpha domains of MT resulted in three As3+ ions coordinating to each of the domains, respectively, in a proposed distorted trigonal pyramid structure. Kinetic analysis provides parameters that allow simulation of the binding of each of the As3+ ions. X-ray absorption spectroscopy provides detailed information about the coordination environment of the absorbing element. We have combined measurement of x-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) data with extensive molecular dynamics calculations to determine accurate metal-thiolate structures. Simulation of the XANES data provides a powerful technique for probing the coordination structures of metals in metalloproteins. The metal binding properties of an algal MT, Fucus vesiculosus, has been investigated by UV absorption and circular dichroism spectroscopy and electrospray ionization-mass spectrometry. The 16 cysteine residues of this algal MT were found to coordinate six Cd2+ ions in two domains with stoichiometries of a novel Cd3S7 cluster and a beta-like Cd3S9 cluster.
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Affiliation(s)
- Kelly E Rigby Duncan
- Department of Chemistry, The University of Western Ontario, London, ON, Canada, N6A 5B7
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25
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Hunaiti AA, Abukhalaf IK, Silvestrov N, Bayorh M. Rapid HPLC Procedure for the Quantitation of Phytochelatins in Plant Tissue Extracts. J LIQ CHROMATOGR R T 2006. [DOI: 10.1081/jlc-120025602] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Abdelrahim A. Hunaiti
- a Department of Biotechnology and Genetic Engineering , Philadelphia University , P.O. Box 1, 19392, Jordan
| | - Imad K. Abukhalaf
- a Department of Biotechnology and Genetic Engineering , Philadelphia University , P.O. Box 1, 19392, Jordan
- b Department of Pharmacology & Toxicology , Morehouse School of Medicine , Atlanta, Georgia, USA
- c Clinical Research Center , Morehouse School of Medicine , Atlanta, Georgia, USA
- d Space Medicine and Life Science Research Center , Morehouse School of Medicine , Atlanta, Georgia, USA
| | - Natalia Silvestrov
- b Department of Pharmacology & Toxicology , Morehouse School of Medicine , Atlanta, Georgia, USA
- c Clinical Research Center , Morehouse School of Medicine , Atlanta, Georgia, USA
| | - Mohamed Bayorh
- b Department of Pharmacology & Toxicology , Morehouse School of Medicine , Atlanta, Georgia, USA
- d Space Medicine and Life Science Research Center , Morehouse School of Medicine , Atlanta, Georgia, USA
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26
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Freeman JL, Persans MW, Nieman K, Salt DE. Nickel and cobalt resistance engineered in Escherichia coli by overexpression of serine acetyltransferase from the nickel hyperaccumulator plant Thlaspi goesingense. Appl Environ Microbiol 2006; 71:8627-33. [PMID: 16332856 PMCID: PMC1317400 DOI: 10.1128/aem.71.12.8627-8633.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The overexpression of serine acetyltransferase from the Ni-hyperaccumulating plant Thlaspi goesingense causes enhanced nickel and cobalt resistance in Escherichia coli. Furthermore, overexpression of T. goesingense serine acetyltransferase results in enhanced sensitivity to cadmium and has no significant effect on resistance to zinc. Enhanced nickel resistance is directly related to the constitutive overactivation of sulfur assimilation and glutathione biosynthesis, driven by the overproduction of O-acetyl-L-serine, the product of serine acetyltransferase and a positive regulator of the cysteine regulon. Nickel in the serine acetyltransferase-overexpressing strains is not detoxified by coordination or precipitation with sulfur, suggesting that glutathione is involved in reducing the oxidative damage imposed by nickel.
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Affiliation(s)
- John L Freeman
- Center for Plant Environmental Stress Physiology, Purdue University, 625 Agricultural Mall Drive, West Lafayette, IN 47907, USA
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27
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Banci L, Bertini I, Ciofi-Baffoni S, Su XC, Miras R, Bal N, Mintz E, Catty P, Shokes JE, Scott RA. Structural basis for metal binding specificity: the N-terminal cadmium binding domain of the P1-type ATPase CadA. J Mol Biol 2005; 356:638-50. [PMID: 16388822 PMCID: PMC3562998 DOI: 10.1016/j.jmb.2005.11.055] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2005] [Revised: 11/17/2005] [Accepted: 11/17/2005] [Indexed: 11/16/2022]
Abstract
In bacteria, P1-type ATPases are responsible for resistance to di- and monovalent toxic heavy metals by taking them out of the cell. These ATPases have a cytoplasmic N terminus comprising metal binding domains defined by a betaalphabetabetaalphabeta fold and a CXXC metal binding motif. To check how the structural properties of the metal binding site in the N terminus can influence the metal specificity of the ATPase, the first structure of a Cd(II)-ATPase N terminus was determined by NMR and its coordination sphere was investigated by X-ray absorption spectroscopy. A novel metal binding environment was found, comprising the two conserved Cys residues of the metal binding motif and a Glu in loop 5. A bioinformatic search identifies an ensemble of highly homologous sequences presumably with the same function. Another group of highly homologous sequences is found which can be referred to as zinc-detoxifying P1-type ATPases with the metal binding pattern DCXXC in the N terminus. Because no carboxylate groups participate in Cu(I) or Ag(I) binding sites, we suggest that the acidic residue plays a key role in the coordination properties of divalent cations, hence conferring a function to the N terminus in the metal specificity of the ATPase.
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Affiliation(s)
- Lucia Banci
- Magnetic Resonance Center CERM and Department of Chemistry, University of Florence, Via Luigi Sacconi 6 50019 Sesto Fiorentino, Florence, Italy
| | - Ivano Bertini
- Magnetic Resonance Center CERM and Department of Chemistry, University of Florence, Via Luigi Sacconi 6 50019 Sesto Fiorentino, Florence, Italy
- Corresponding authors: ;
| | - Simone Ciofi-Baffoni
- Magnetic Resonance Center CERM and Department of Chemistry, University of Florence, Via Luigi Sacconi 6 50019 Sesto Fiorentino, Florence, Italy
| | - Xun-Cheng Su
- Magnetic Resonance Center CERM and Department of Chemistry, University of Florence, Via Luigi Sacconi 6 50019 Sesto Fiorentino, Florence, Italy
| | - Roger Miras
- Laboratoire de Biophysique Moléculaire et Cellulaire UMR 5090 CEA-CNRS-Université Joseph Fourier CEA/DRDC/BMC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Nathalie Bal
- Laboratoire de Biophysique Moléculaire et Cellulaire UMR 5090 CEA-CNRS-Université Joseph Fourier CEA/DRDC/BMC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Elisabeth Mintz
- Laboratoire de Biophysique Moléculaire et Cellulaire UMR 5090 CEA-CNRS-Université Joseph Fourier CEA/DRDC/BMC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Patrice Catty
- Laboratoire de Biophysique Moléculaire et Cellulaire UMR 5090 CEA-CNRS-Université Joseph Fourier CEA/DRDC/BMC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
- Corresponding authors: ;
| | - Jacob E. Shokes
- Center for Metalloenzyme Studies and the Department of Chemistry, University of Georgia, Athens, GA 30602-2556 USA
| | - Robert A. Scott
- Center for Metalloenzyme Studies and the Department of Chemistry, University of Georgia, Athens, GA 30602-2556 USA
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Raab A, Schat H, Meharg AA, Feldmann J. Uptake, translocation and transformation of arsenate and arsenite in sunflower (Helianthus annuus): formation of arsenic-phytochelatin complexes during exposure to high arsenic concentrations. THE NEW PHYTOLOGIST 2005; 168:551-8. [PMID: 16313638 DOI: 10.1111/j.1469-8137.2005.01519.x] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The aim of the study was to determine the time-dependent formation of arsenic-phytochelatin (As-PC) complexes in the roots, stems and leaves of an arsenic-nontolerant plant (Helianthus annuus) during exposure to 66 mol l(-1) arsenite (As(III)) or arsenate (As(V)). We used our previously developed method of simultaneous element-specific (inductively coupled plasma mass spectrometry, ICP-MS) and molecular-specific (electrospray-ionization mass spectrometry, ES-MS) detection systems interfaced with a suitable chromatographic column and eluent conditions, which enabled us to identify and quantify As-PC complexes directly. Roots of As-exposed H. annuus contained up to 14 different arsenic species, including the complex of arsenite with two (gamma-Glu-Cys)(2)-Gly molecules [As((III))-(PC(2))(2)], the newly identified monomethylarsonic phytochelatin-2 or (gamma-Glu-Cys)(2)-Gly CH(3)As (MA((III))-PC(2)) and at least eight not yet identified species. The complex of arsenite with (gamma-Glu-Cys)(3)-Gly (As((III))-PC(3)) and the complex of arsenite with glutathione (GSH) and (gamma-Glu-Cys)(2)-Gly (GS-As((III))-PC(2)) were present in all samples (roots, stems and leaves) taken from plants exposed to As. The GS-As((III))-PC(2) complex was the dominant complex after 1 h of exposure. As((III))-PC(3) became the predominant As-PC complex after 3 h, binding up to 40% of the As present in the exposed plants. No As-PC complexes were found in sap (mainly xylem sap from the root system), in contrast to roots, stems and leaves, which is unequivocal evidence that As-PC complexes are not involved in the translocation of As from root to leaves of H. annuus.
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Affiliation(s)
- Andrea Raab
- Department of Chemistry, University of Aberdeen, Meston Building, Meston Walk, Aberdeen AB24 3UE, UK
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Van Hoewyk D, Garifullina GF, Ackley AR, Abdel-Ghany SE, Marcus MA, Fakra S, Ishiyama K, Inoue E, Pilon M, Takahashi H, Pilon-Smits EAH. Overexpression of AtCpNifS enhances selenium tolerance and accumulation in Arabidopsis. PLANT PHYSIOLOGY 2005; 139:1518-28. [PMID: 16244144 PMCID: PMC1283786 DOI: 10.1104/pp.105.068684] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Selenium (Se) is an essential element for many organisms but is toxic at higher levels. CpNifS is a chloroplastic NifS-like protein in Arabidopsis (Arabidopsis thaliana) that can catalyze the conversion of cysteine into alanine and elemental sulfur (S0) and of selenocysteine into alanine and elemental Se (Se0). We overexpressed CpNifS to investigate the effects on Se metabolism in plants. CpNifS overexpression significantly enhanced selenate tolerance (1.9-fold) and Se accumulation (2.2-fold). CpNifS overexpressors showed significantly reduced Se incorporation into protein, which may explain their higher Se tolerance. Also, sulfur accumulation was enhanced by approximately 30% in CpNifS overexpressors, both on media with and without selenate. Root transcriptome changes in response to selenate mimicked the effects observed under sulfur starvation. There were only a few transcriptome differences between CpNifS-overexpressing plants and wild type, besides the 25- to 40-fold increase in CpNifS levels. Judged from x-ray analysis of near edge spectrum, both CpNifS overexpressors and wild type accumulated mostly selenate (Se(VI)). In conclusion, overexpression of this plant NifS-like protein had a pronounced effect on plant Se metabolism. The observed enhanced Se accumulation and tolerance of CpNifS overexpressors show promise for use in phytoremediation.
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Affiliation(s)
- Douglas Van Hoewyk
- Biology Department, Colorado State University, Fort Collins, CO 80523, USA
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30
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Phillips CJC, Chiy PC, Zachou E. Effects of cadmium in herbage on the apparent absorption of elements by sheep in comparison with inorganic cadmium added to their diet. ENVIRONMENTAL RESEARCH 2005; 99:224-34. [PMID: 16194672 DOI: 10.1016/j.envres.2004.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2004] [Revised: 12/10/2004] [Accepted: 12/22/2004] [Indexed: 05/04/2023]
Abstract
A meta-analysis of existing scientific literature recently suggested that Cd is absorbed more efficiently by sheep if it is in the organic form in grass, than if it is added as an inorganic supplement to the diet. We tested this experimentally by feeding sheep grass from contaminated soil, compared with uncontaminated grass and with Cd added to the diet. To produce contaminated herbage, Cd nitrate was added to soil in 11 lysimeters sown with perennial ryegrass, with a further 11 lysimeters receiving no Cd to produce uncontaminated herbage. In the Cd-treated lysimeters, soil had increased exchangeable K, Mg, and Ca, leachate had increased K, Mg, Ca, Na, and P, grass had increased Cd and reduced Mg, Na, P, Mn, Fe, Cr, Al, and Ni, and there was some reduction in grass yield compared with untreated lysimeters. Grass from Cd-treated or untreated lysimeters was fed to groups of 12 ewes for 2 days, with Cd intake equated by adding Cd nitrate to the concentrate feed of ewes receiving the uncontaminated grass. The apparent absorption of Cd, Zn, Mo, Cr, and Al was increased for ewes receiving Cd-enriched grass, and apparent absorption of Cu was reduced, compared to those receiving supplementary inorganic Cd. Most of the unabsorbed Cd was excreted in feces within 4 days of feeding. The ewes consuming Cd in grass had increased B concentrations in their urine, possibly due to adverse effects of Cd on kidney function. Finally, the ewes were offered a choice of the two herbages and they ate significantly more of the uncontaminated grass. It is concluded that the apparent absorption of Cd and other heavy metals by sheep in a short-term experiment was greater when Cd was in the grass than when the Cd was added in in an inorganic form and that sheep partially avoided herbage with a high Cd concentration.
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Affiliation(s)
- C J C Phillips
- Department of Clinical Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK.
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31
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Chan J, Merrifield ME, Soldatov AV, Stillman MJ. XAFS Spectral Analysis of the Cadmium Coordination Geometry in Cadmium Thiolate Clusters in Metallothionein. Inorg Chem 2005; 44:4923-33. [PMID: 15998019 DOI: 10.1021/ic048871n] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the combination of measurement and prediction of X-ray absorption fine structure (XAFS) data, where the term XAFS refers to the overall spectrum that encompasses both the X-ray Absorption Near Edge Structure (XANES) region as well as the Extended X-ray Absorption Fine Structure (EXAFS) region, to evaluate the cadmium thiolate cluster structures in the metalloprotein metallothionein. XAFS spectra were simulated using coordinates from molecular models of the protein calculated by molecular mechanics/molecular dynamics (MM3/MD), from NMR analyses, and from analysis of X-ray diffraction data. XAFS spectra were also simulated using the coordinates from X-ray crystallographic data for [Cd(SPh)4]2-, CdS, [Cd2(mu-SPh)2(SPh)4]2-, and [Cd4(mu-SPh)6(SPh)4]2-. The simulated XAFS data that were calculated using the FEFF8 program closely resemble the experimental data reported for [Cd(SPh)4]2-, CdS, [Cd2(mu-SPh)2(SPh)4]2-, [Cd4(mu-SPh)6(SPh)4]2-, rabbit liver metallothionein cadmium alpha-domain (Cd4-alpha MT), and cadmium rabbit liver betaalpha metallothionein (Cd7-betaalpha MT). MM3 force field parameters were modified to include cadmium-sulfur bonding and were initially set to values derived from published X-ray diffraction and EXAFS experimental data. The force field was further calibrated and adjusted through comparison between experimental spectra taken from the literature and simulated XAFS spectra calculated using the FEFF8 program in combination with atomic coordinates from MM3/MD energy minimization. MM3/MD techniques were used with the calibrated force field to predict the high-resolution structure of the metal clusters in rabbit liver Cd7-MT. Structures for Cd3S9 (beta) MT and Cd4S11 (alpha) MT domains from MM3/MD calculations and those previously reported for Cd7-MT on the basis of 1H and 113Cd NMR data were compared. Structural differences between the different models for these cadmium thiolate clusters were evident. Combining the measurement and simulation of XAFS data provides an excellent method of assessing, modeling, and predicting metal-binding sites in metalloproteins when X-ray absorption spectroscopy (XAS) data are available.
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Affiliation(s)
- Jayna Chan
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7 Canada
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32
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Lane TW, Saito MA, George GN, Pickering IJ, Prince RC, Morel FMM. Biochemistry: a cadmium enzyme from a marine diatom. Nature 2005; 435:42. [PMID: 15875011 DOI: 10.1038/435042a] [Citation(s) in RCA: 303] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ocean biota contains a vast reservoir of genomic diversity. Here we present the sequence and preliminary characterization of a protein that is a cadmium-containing carbonic anhydrase from the marine diatom Thalassiosira weissflogii. The existence of a cadmium enzyme in marine phytoplankton may indicate that there is a unique selection pressure for metalloenzymes in the marine environment, and our discovery provides a long-awaited explanation for the nutrient-like behaviour of cadmium in the oceans.
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Affiliation(s)
- Todd W Lane
- Biosystems Research Department, Sandia National Laboratories, Livermore, California 94551-0969, USA
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33
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Marmiroli M, Antonioli G, Maestri E, Marmiroli N. Evidence of the involvement of plant ligno-cellulosic structure in the sequestration of Pb: an X-ray spectroscopy-based analysis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2005; 134:217-227. [PMID: 15589649 DOI: 10.1016/j.envpol.2004.08.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Accepted: 08/06/2004] [Indexed: 05/24/2023]
Abstract
European walnut (Juglans regia) plants were grown in pots, on peat soil contaminated with lead (Pb), for four years. European walnut was chosen because it grows in Mediterranean climates, it yields a high biomass, and a fine quality wood. In the above ground parts Pb concentration was 1000 times lower than in roots: in 50 g roots there was 450 mg of Pb. Microanalysis of roots found in periderm more than 50% of the total root Pb. Pb L(III) EXAFS spectroscopy was performed on: root powder from Pb-exposed plants, Pb-impregnated cellulose and lignin. Comparison of plant material with lignin and cellulose helped to envisage a plant disposal strategy for Pb. This may consist in establishing links with large organic molecules, which are abundant constituents of cell walls. EXAFS spectroscopy evidenced the presence of Pb-O bindings within the ligno-cellulosic structure in roots. Lead was scantly conveyed to the shoots, giving to walnut plants an added asset in Pb phytostabilization.
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Affiliation(s)
- Marta Marmiroli
- Department of Environmental Sciences, University of Parma, Parco Area delle Scienze 11/A, 43100 Parma, Italy
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34
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Freeman JL, Persans MW, Nieman K, Albrecht C, Peer W, Pickering IJ, Salt DE. Increased glutathione biosynthesis plays a role in nickel tolerance in thlaspi nickel hyperaccumulators. THE PLANT CELL 2004; 16:2176-91. [PMID: 15269333 PMCID: PMC519206 DOI: 10.1105/tpc.104.023036] [Citation(s) in RCA: 236] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Accepted: 05/05/2004] [Indexed: 05/04/2023]
Abstract
Worldwide more than 400 plant species are now known that hyperaccumulate various trace metals (Cd, Co, Cu, Mn, Ni, and Zn), metalloids (As) and nonmetals (Se) in their shoots. Of these, almost one-quarter are Brassicaceae family members, including numerous Thlaspi species that hyperaccumulate Ni up to 3% of there shoot dry weight. We observed that concentrations of glutathione, Cys, and O-acetyl-l-serine (OAS), in shoot tissue, are strongly correlated with the ability to hyperaccumulate Ni in various Thlaspi hyperaccumulators collected from serpentine soils, including Thlaspi goesingense, T. oxyceras, and T. rosulare, and nonaccumulator relatives, including T. perfoliatum, T. arvense, and Arabidopsis thaliana. Further analysis of the Austrian Ni hyperaccumulator T. goesingense revealed that the high concentrations of OAS, Cys, and GSH observed in this hyperaccumulator coincide with constitutively high activity of both serine acetyltransferase (SAT) and glutathione reductase. SAT catalyzes the acetylation of l-Ser to produce OAS, which acts as both a key positive regulator of sulfur assimilation and forms the carbon skeleton for Cys biosynthesis. These changes in Cys and GSH metabolism also coincide with the ability of T. goesingense to both hyperaccumulate Ni and resist its damaging oxidative effects. Overproduction of T. goesingense SAT in the nonaccumulator Brassicaceae family member Arabidopsis was found to cause accumulation of OAS, Cys, and glutathione, mimicking the biochemical changes observed in the Ni hyperaccumulators. In these transgenic Arabidopsis, glutathione concentrations strongly correlate with increased resistance to both the growth inhibitory and oxidative stress induced effects of Ni. Taken together, such evidence supports our conclusion that elevated GSH concentrations, driven by constitutively elevated SAT activity, are involved in conferring tolerance to Ni-induced oxidative stress in Thlaspi Ni hyperaccumulators.
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Affiliation(s)
- John L Freeman
- Center for Plant Environmental Stress Physiology, Purdue University, West Lafayette, Indiana 47907, USA
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35
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de la Rosa G, Peralta-Videa JR, Montes M, Parsons JG, Cano-Aguilera I, Gardea-Torresdey JL. Cadmium uptake and translocation in tumbleweed (Salsola kali), a potential Cd-hyperaccumulator desert plant species: ICP/OES and XAS studies. CHEMOSPHERE 2004; 55:1159-68. [PMID: 15081756 DOI: 10.1016/j.chemosphere.2004.01.028] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2003] [Revised: 12/19/2003] [Accepted: 01/20/2004] [Indexed: 05/08/2023]
Abstract
Cadmium is a heavy metal, which, even at low concentrations, can be highly toxic to the growth and development of both plants and animals. Plant species vary extensively in their tolerance to excess cadmium in a growth medium and very few cadmium-tolerant species have been identified. In this study, tumbleweed plants (Salsola kali) grown in an agar-based medium with 20 mgl(-1) of Cd(II) did not show phytotoxicity, and their roots had the most biomass (4.5 mg) (P < 0.05) compared to the control plants (2.7 mg) as well as other treated plants. These plants accumulated 2696, 2075, and 2016 mg Cd kg(-1) of dry roots, stems, and leaves, respectively. The results suggest that there is no restricted cadmium movement in tumbleweed plants. In addition, the amount of Cd found in the dry leaf tissue suggests that tumbleweed could be considered as potential cadmium hyperaccumulating species. X-ray absorption spectroscopy studies demonstrated that in roots, cadmium was bound to oxygen while in stems and leaves, the metal was attached to oxygen and sulfur groups. This might imply that some small organic acids are responsible for Cd transport from roots to stems and leaves. In addition, it might be possible that the plant synthesizes phytochelatins in the stems, later coordinating the absorbed cadmium for transport and storage in cell structures. Thus, it is possible that in the leaves, Cd either exists as a Cd-phytochelatin complex or bound to cell wall structures. Current studies are being performed in order to elucidate the proposed hypothesis.
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Affiliation(s)
- Guadalupe de la Rosa
- Environmental Science and Engineering, University of Texas at El Paso, El Paso, TX 79968, USA
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36
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Raab A, Feldmann J, Meharg AA. The nature of arsenic-phytochelatin complexes in Holcus lanatus and Pteris cretica. PLANT PHYSIOLOGY 2004; 134:1113-22. [PMID: 15001701 PMCID: PMC389935 DOI: 10.1104/pp.103.033506] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2003] [Revised: 10/19/2003] [Accepted: 12/04/2003] [Indexed: 05/17/2023]
Abstract
We have developed a method to extract and separate phytochelatins (PCs)-metal(loid) complexes using parallel metal(loid)-specific (inductively coupled plasma-mass spectrometry) and organic-specific (electrospray ionization-mass spectrometry) detection systems-and use it here to ascertain the nature of arsenic (As)-PC complexes in plant extracts. This study is the first unequivocal report, to our knowledge, of PC complex coordination chemistry in plant extracts for any metal or metalloid ion. The As-tolerant grass Holcus lanatus and the As hyperaccumulator Pteris cretica were used as model plants. In an in vitro experiment using a mixture of reduced glutathione (GS), PC(2), and PC(3), As preferred the formation of the arsenite [As((III))]-PC(3) complex over GS-As((III))-PC(2), As((III))-(GS)(3), As((III))-PC(2), or As((III))-(PC(2))(2) (GS: glutathione bound to arsenic via sulphur of cysteine). In H. lanatus, the As((III))-PC(3) complex was the dominant complex, although reduced glutathione, PC(2), and PC(3) were found in the extract. P. cretica only synthesizes PC(2) and forms dominantly the GS-As((III))-PC(2) complex. This is the first evidence, to our knowledge, for the existence of mixed glutathione-PC-metal(loid) complexes in plant tissues or in vitro. In both plant species, As is dominantly in non-bound inorganic forms, with 13% being present in PC complexes for H. lanatus and 1% in P. cretica.
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Affiliation(s)
- Andrea Raab
- Department of Chemistry, University of Aberdeen, Meston Building, Meston Walk, Aberdeen AB24 3UE, United Kingdom
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37
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Küpper H, Mijovilovich A, Meyer-Klaucke W, Kroneck PMH. Tissue- and age-dependent differences in the complexation of cadmium and zinc in the cadmium/zinc hyperaccumulator Thlaspi caerulescens (Ganges ecotype) revealed by x-ray absorption spectroscopy. PLANT PHYSIOLOGY 2004; 134:748-57. [PMID: 14966248 PMCID: PMC344550 DOI: 10.1104/pp.103.032953] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Revised: 09/24/2003] [Accepted: 11/11/2003] [Indexed: 05/17/2023]
Abstract
Extended x-ray absorption fine structure measurements were performed on frozen hydrated samples of the cadmium (Cd)/zinc (Zn) hyperaccumulator Thlaspi caerulescens (Ganges ecotype) after 6 months of Zn(2+) treatment with and without addition of Cd(2+). Ligands depended on the metal and the function and age of the plant tissue. In mature and senescent leaves, oxygen ligands dominated. This result combined with earlier knowledge about metal compartmentation indicates that the plants prefer to detoxify hyperaccumulated metals by pumping them into vacuoles rather than to synthesize metal specific ligands. In young and mature tissues (leaves, petioles, and stems), a higher percentage of Cd was bound by sulfur (S) ligands (e.g. phytochelatins) than in senescent tissues. This may indicate that young tissues require strong ligands for metal detoxification in addition to the detoxification by sequestration in the epidermal vacuoles. Alternatively, it may reflect the known smaller proportion of epidermal metal sequestration in younger tissues, combined with a constant and high proportion of S ligands in the mesophyll. In stems, a higher proportion of Cd was coordinated by S ligands and of Zn by histidine, compared with leaves of the same age. This may suggest that metals are transported as stable complexes or that the vacuolar oxygen coordination of the metals is, like in leaves, mainly found in the epidermis. The epidermis constitutes a larger percentage of the total volume in leaves than in stems and petioles. Zn-S interaction was never observed, confirming earlier results that S ligands are not involved in Zn resistance of hyperaccumulator plants.
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Affiliation(s)
- Hendrik Küpper
- Universität Konstanz, Mathematisch-Naturwissenschaftliche Sektion, Fachbereich Biologie, Postfach M665, D-78457 Konstanz, Germany.
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38
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Dorčák V, Krężel A. Correlation of acid–base chemistry of phytochelatin PC2 with its coordination properties towards the toxic metal ion Cd(ii). Dalton Trans 2003. [DOI: 10.1039/b301357j] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Salt DE, Prince RC, Pickering IJ. Chemical speciation of accumulated metals in plants: evidence from X-ray absorption spectroscopy. Microchem J 2002. [DOI: 10.1016/s0026-265x(02)00017-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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40
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Cruz BH, Dı́az-Cruz JM, Šestáková I, Velek J, Ariño C, Esteban M. Differential pulse voltammetric study of the complexation of Cd(II) by the phytochelatin (γ-GluCys)2Gly assisted by multivariate curve resolution. J Electroanal Chem (Lausanne) 2002. [DOI: 10.1016/s0022-0728(02)00640-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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41
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Abstract
A low molecular weight (6-7 kDa) class of metalloproteins, designated as metallothioneins (MTs), exhibit repeated sequence motifs of either CxC or CxxC through which mono or divalent d(10) metal ions are bound in polymetallic-thiolate clusters. The preservation of metal-thiolate clusters in an increasing number of three-dimensional structures of these proteins signifies the importance of this structural motif. This review focuses on the recent developments regarding the versatile and striking chemical reactivity of MTs as well as on the existence of conformational/configurational dynamics within their structure. Both properties and their interplay are likely to be essential for the still elusive biological function of these proteins.
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Affiliation(s)
- Núria Romero-Isart
- Institute of Biochemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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42
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Yu EY, Pickering IJ, George GN, Prince RC. In situ observation of the generation of isothiocyanates from sinigrin in horseradish and wasabi. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1527:156-60. [PMID: 11479032 DOI: 10.1016/s0304-4165(01)00161-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sulfur K-edge X-ray absorption spectroscopy has been used to determine the chemical identity of the sulfur-containing species in horseradish (Armoracia lapthifolia) and wasabi (Wasabia japonica) in situ, before and after cell disruption. The major sulfur-containing species in the intact root is sinigrin (1-thio-beta-D-glucopyranose 1-N-(sulfoxy)-3-buteneimidate) and related congeners. Disrupting the cells by applying local pressure allowed the conversion of the sulfur moieties in sinigrin to isothiocyanates and sulfate in approximately equimolar amounts. In contrast to previous suggestions, no detectable thiocyanates were formed, but an unusual thio intermediate may have been identified for the first time.
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Affiliation(s)
- E Y Yu
- Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, CA 94025, USA
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43
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Hale KL, McGrath SP, Lombi E, Stack SM, Terry N, Pickering IJ, George GN, Pilon-Smits EA. Molybdenum sequestration in Brassica species. A role for anthocyanins? PLANT PHYSIOLOGY 2001; 126:1391-402. [PMID: 11500539 PMCID: PMC117140 DOI: 10.1104/pp.126.4.1391] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2001] [Revised: 04/09/2001] [Accepted: 04/30/2001] [Indexed: 05/17/2023]
Abstract
To elucidate plant mechanisms involved in molybdenum (Mo) sequestration and tolerance, Brassica spp. seedlings were supplied with molybdate, and the effects on plant physiology, morphology, and biochemistry were analyzed. When supplied with (colorless) molybdate Indian mustard (Brassica juncea) seedlings accumulated water-soluble blue crystals in their peripheral cell layers. Energy dispersive x-ray analysis showed that Mo accumulated predominantly in the vacuoles of the epidermal cells. Therefore, the blue crystals are likely to be a Mo compound. The x-ray absorption spectrum of the plant-accumulated Mo was different than that for molybdate, indicating complexation with a plant molecule. Because the blue compound was water soluble and showed a pH-dependent color change, possible involvement of anthocyanins was investigated. An anthocyanin-less mutant of Brassica rapa ("fast plants") was compared with varieties containing normal or high anthocyanin levels. The anthocyanin-less mutant did not show accumulation of a blue compound when supplied with molybdate. In the anthocyanin-containing varieties, the blue compound colocalized with anthocyanins in the peripheral cell layers. Mo accumulation by the three B. rapa varieties was positively correlated with anthocyanin content. Addition of molybdate to purified B. rapa anthocyanin resulted in an in vitro color change from pink to blue. Therefore, Mo appears to be sequestered in vacuoles of the peripheral cell layers of Brassica spp. as a blue compound, probably a Mo-anthocyanin complex.
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Affiliation(s)
- K L Hale
- Department of Biology, Anatomy/Zoology Building, Colorado State University, Fort Collins, Colorado 80523, USA
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44
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Persans MW, Salt DE. Possible molecular mechanisms involved in nickel, zinc and selenium hyperaccumulation in plants. Biotechnol Genet Eng Rev 2001; 17:389-413. [PMID: 11255675 DOI: 10.1080/02648725.2000.10647999] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- M W Persans
- Chemistry Department, Northern Arizona University, Flagstaff, AZ 86011, USA
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45
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The Role of Glutathione in Plant Reaction and Adaptation to Excess Metals. PLANT ECOPHYSIOLOGY 2001. [DOI: 10.1007/0-306-47644-4_6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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46
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Gailer J, George GN, Pickering IJ, Madden S, Prince RC, Yu EY, Denton MB, Younis HS, Aposhian HV. Structural basis of the antagonism between inorganic mercury and selenium in mammals. Chem Res Toxicol 2000; 13:1135-42. [PMID: 11087435 DOI: 10.1021/tx000050h] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mercuric chloride toxicity in mammals can be overcome by co-administration of sodium selenite. We report a study of the mutual detoxification product in rabbit plasma, and of a Hg-Se-S-containing species synthesized by addition of equimolar mercuric chloride and sodium selenite to aqueous, buffered glutathione. Chromatographic purification of this Hg-Se-S species and subsequent structural analysis by Se and Hg extended X-ray absorption fine structure (EXAFS) spectroscopy revealed the presence of four-coordinate Se and Hg entities separated by 2.61 A. Hg and Se near-edge X-ray absorption spectroscopy of erythrocytes, plasma, and bile of rabbits that had been injected with solutions of sodium selenite and mercuric chloride showed that Hg and Se in plasma samples exhibited X-ray absorption spectra that were essentially identical to those of the synthetic Hg-Se-S species. Thus, the molecular detoxification product of sodium selenite and mercuric chloride in rabbits exhibits similarities to the synthetic Hg-Se-S species. The underlying molecular mechanism for the formation of the Hg-Se-S species is discussed.
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Affiliation(s)
- J Gailer
- Department of Molecular and Cellular Biology, The University of Arizona, Life Sciences South Building, Tucson, Arizona 85721, USA
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47
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Meagher RB. Phytoremediation of toxic elemental and organic pollutants. CURRENT OPINION IN PLANT BIOLOGY 2000; 3:153-62. [PMID: 10712958 DOI: 10.1016/s1369-5266(99)00054-0] [Citation(s) in RCA: 246] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Phytoremediation is the use of plants to extract, sequester, and/or detoxify pollutants. Phytoremediation is widely viewed as the ecologically responsible alternative to the environmentally destructive physical remediation methods currently practiced. Plants have many endogenous genetic, biochemical, and physiological properties that make them ideal agents for soil and water remediation. Significant progress has been made in recent years in developing native or genetically modified plants for the remediation of environmental contaminants. Because elements are immutable, phytoremediation strategies for radionuclide and heavy metal pollutants focus on hyperaccumulation above-ground. In contrast, organic pollutants can potentially be completely mineralized by plants.
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Affiliation(s)
- R B Meagher
- Department of Genetics, University of Georgia, Athens 30602, USA.
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48
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Pickering IJ, Prince RC, George MJ, Smith RD, George GN, Salt DE. Reduction and coordination of arsenic in Indian mustard. PLANT PHYSIOLOGY 2000; 122:1171-7. [PMID: 10759512 PMCID: PMC58951 DOI: 10.1104/pp.122.4.1171] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/1999] [Accepted: 12/04/1999] [Indexed: 05/17/2023]
Abstract
The bioaccumulation of arsenic by plants may provide a means of removing this element from contaminated soils and waters. However, to optimize this process it is important to understand the biological mechanisms involved. Using a combination of techniques, including x-ray absorption spectroscopy, we have established the biochemical fate of arsenic taken up by Indian mustard (Brassica juncea). After arsenate uptake by the roots, possibly via the phosphate transport mechanism, a small fraction is exported to the shoot via the xylem as the oxyanions arsenate and arsenite. Once in the shoot, the arsenic is stored as an As(III)-tris-thiolate complex. The majority of the arsenic remains in the roots as an As(III)-tris-thiolate complex, which is indistinguishable from that found in the shoots and from As(III)-tris-glutathione. The thiolate donors are thus probably either glutathione or phytochelatins. The addition of the dithiol arsenic chelator dimercaptosuccinate to the hydroponic culture medium caused a 5-fold-increased arsenic level in the leaves, although the total arsenic accumulation was only marginally increased. This suggests that the addition of dimercaptosuccinate to arsenic-contaminated soils may provide a way to promote arsenic bioaccumulation in plant shoots, a process that will be essential for the development of an efficient phytoremediation strategy for this element.
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Affiliation(s)
- I J Pickering
- Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford Linear Accelerator Center, Stanford, California 94309, USA
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Schmöger ME, Oven M, Grill E. Detoxification of arsenic by phytochelatins in plants. PLANT PHYSIOLOGY 2000; 122:793-801. [PMID: 10712543 PMCID: PMC58915 DOI: 10.1104/pp.122.3.793] [Citation(s) in RCA: 287] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/1999] [Accepted: 11/29/1999] [Indexed: 05/18/2023]
Abstract
As is a ubiquitous element present in the atmosphere as well as in the aquatic and terrestrial environments. Arsenite and arsenate are the major forms of As intoxication, and these anions are readily taken up by plants. Both anions efficiently induce the biosynthesis of phytochelatins (PCs) ([gamma-glutamate-cysteine](n)-glycine) in vivo and in vitro. The rapid induction of the metal-binding PCs has been observed in cell suspension cultures of Rauvolfia serpentina, in seedlings of Arabidopsis, and in enzyme preparations of Silene vulgaris upon challenge to arsenicals. The rate of PC formation in enzyme preparations was lower compared with Cd-induced biosynthesis, but was accompanied by a prolonged induction phase that resulted finally in higher peptide levels. An approximately 3:1 ratio of the sulfhydryl groups from PCs to As is compatible with reported As-glutathione complexes. The identity of the As-induced PCs and of reconstituted metal-peptide complexes has unequivocally been demonstrated by electrospray ionization mass spectroscopy. Gel filtration experiments and inhibitor studies also indicate a complexation and detoxification of As by the induced PCs.
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Affiliation(s)
- M E Schmöger
- Lehrstuhl für Botanik, Technische Universität München, Biologikum-Weihenstephan, Am Hochanger 4, 85350 Freising, Germany
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Satofuka H, Amano S, Atomi H, Takagi M, Hirata K, Miyamoto K, Imanaka T. Rapid method for detection and detoxification of heavy metal ions in water environments using phytochelation. J Biosci Bioeng 1999; 88:287-92. [PMID: 16232613 DOI: 10.1016/s1389-1723(00)80011-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/1999] [Accepted: 06/16/1999] [Indexed: 10/18/2022]
Abstract
Phytochelatins (PCs, (gammaGlu-Cys)n-Gly (n = 2-11)) are produced by higher plants, algae, and some fungi in response to heavy metal ion exposure. A rapid and convenient method for quantifying heavy metal ion concentrations in water environments was developed using a chemically synthesized PC as a mediator. The chelating ability of the PC and quantification of the thiol group were utilized to measure heavy metal ions at low concentrations. The method requires only ten minutes for measurement and only 1 ml of a liquid sample. A range of homogeneous PCs (n = 4-7) were chemically synthesized using a peptide synthesizer. These, especially PC7, exhibited higher sensitivity and consistency of measurement than the native PC from Silene cucubalus, which produced a mixture of PC2, PC3, and PC4. Detoxification of heavy metal ions in vitro by PC was also investigated. Using the paper disc method, the cell growth inhibition zone caused by cadmium ion against Salmonella typhimurium TA1538 was significantly decreased by addition of PC. Furthermore, at the minimum inhibitory concentration of cadmium ion (200 microM) in a nutrient broth culture of S. typhimurium, cell growth was almost completely recovered by addition of PC to the medium.
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Affiliation(s)
- H Satofuka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan
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