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Seregin IV, Kozhevnikova AD. Phytochelatins: Sulfur-Containing Metal(loid)-Chelating Ligands in Plants. Int J Mol Sci 2023; 24:2430. [PMID: 36768751 PMCID: PMC9917255 DOI: 10.3390/ijms24032430] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 01/28/2023] Open
Abstract
Phytochelatins (PCs) are small cysteine-rich peptides capable of binding metal(loid)s via SH-groups. Although the biosynthesis of PCs can be induced in vivo by various metal(loid)s, PCs are mainly involved in the detoxification of cadmium and arsenic (III), as well as mercury, zinc, lead, and copper ions, which have high affinities for S-containing ligands. The present review provides a comprehensive account of the recent data on PC biosynthesis, structure, and role in metal(loid) transport and sequestration in the vacuoles of plant cells. A comparative analysis of PC accumulation in hyperaccumulator plants, which accumulate metal(loid)s in their shoots, and in the excluders, which accumulate metal(loid)s in their roots, investigates the question of whether the endogenous PC concentration determines a plant's tolerance to metal(loid)s. Summarizing the available data, it can be concluded that PCs are not involved in metal(loid) hyperaccumulation machinery, though they play a key role in metal(loid) homeostasis. Unraveling the physiological role of metal(loid)-binding ligands is a fundamental problem of modern molecular biology, plant physiology, ionomics, and toxicology, and is important for the development of technologies used in phytoremediation, biofortification, and phytomining.
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Affiliation(s)
- Ilya V. Seregin
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya St., 35, 127276 Moscow, Russia
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Seregin IV, Kozhevnikova AD. Low-molecular-weight ligands in plants: role in metal homeostasis and hyperaccumulation. PHOTOSYNTHESIS RESEARCH 2021; 150:51-96. [PMID: 32653983 DOI: 10.1007/s11120-020-00768-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
Mineral nutrition is one of the key factors determining plant productivity. In plants, metal homeostasis is achieved through the functioning of a complex system governing metal uptake, translocation, distribution, and sequestration, leading to the maintenance of a regulated delivery of micronutrients to metal-requiring processes as well as detoxification of excess or non-essential metals. Low-molecular-weight ligands, such as nicotianamine, histidine, phytochelatins, phytosiderophores, and organic acids, play an important role in metal transport and detoxification in plants. Nicotianamine and histidine are also involved in metal hyperaccumulation, which determines the ability of some plant species to accumulate a large amount of metals in their shoots. In this review we extensively summarize and discuss the current knowledge of the main pathways for the biosynthesis of these ligands, their involvement in metal uptake, radial and long-distance transport, as well as metal influx, isolation and sequestration in plant tissues and cell compartments. It is analyzed how diverse endogenous ligand levels in plants can determine their different tolerance to metal toxic effects. This review focuses on recent advances in understanding the physiological role of these compounds in metal homeostasis, which is an essential task of modern ionomics and plant physiology. It is of key importance in studying the influence of metal deficiency or excess on various physiological processes, which is a prerequisite to the improvement of micronutrient uptake efficiency and crop productivity and to the development of a variety of applications in phytoremediation, phytomining, biofortification, and nutritional crop safety.
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Affiliation(s)
- I V Seregin
- K.A. Timiryazev Institute of Plant Physiology RAS, IPPRAS, Botanicheskaya st., 35, Moscow, Russian Federation, 127276.
| | - A D Kozhevnikova
- K.A. Timiryazev Institute of Plant Physiology RAS, IPPRAS, Botanicheskaya st., 35, Moscow, Russian Federation, 127276
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Gutsch A, Hendrix S, Guerriero G, Renaut J, Lutts S, Alseekh S, Fernie AR, Hausman JF, Vangronsveld J, Cuypers A, Sergeant K. Long-Term Cd Exposure Alters the Metabolite Profile in Stem Tissue of Medicago sativa. Cells 2020; 9:E2707. [PMID: 33348837 PMCID: PMC7765984 DOI: 10.3390/cells9122707] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 12/15/2022] Open
Abstract
As a common pollutant, cadmium (Cd) is one of the most toxic heavy metals accumulating in agricultural soils through anthropogenic activities. The uptake of Cd by plants is the main entry route into the human food chain, whilst in plants it elicits oxidative stress by unbalancing the cellular redox status. Medicago sativa was subjected to chronic Cd stress for five months. Targeted and untargeted metabolic analyses were performed. Long-term Cd exposure altered the amino acid composition with levels of asparagine, histidine and proline decreasing in stems but increasing in leaves. This suggests tissue-specific metabolic stress responses, which are often not considered in environmental studies focused on leaves. In stem tissue, profiles of secondary metabolites were clearly separated between control and Cd-exposed plants. Fifty-one secondary metabolites were identified that changed significantly upon Cd exposure, of which the majority are (iso)flavonoid conjugates. Cadmium exposure stimulated the phenylpropanoid pathway that led to the accumulation of secondary metabolites in stems rather than cell wall lignification. Those metabolites are antioxidants mitigating oxidative stress and preventing cellular damage. By an adequate adjustment of its metabolic composition, M. sativa reaches a new steady state, which enables the plant to acclimate under chronic Cd stress.
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Affiliation(s)
- Annelie Gutsch
- GreenTech Innovation Center, Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, 4362 Esch-sur-Alzette, Luxembourg; (A.G.); (G.G.); (J.R.); (J.-F.H.)
- Centre for Environmental Sciences, Campus Diepenbeek, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; (S.H.); (J.V.); (A.C.)
| | - Sophie Hendrix
- Centre for Environmental Sciences, Campus Diepenbeek, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; (S.H.); (J.V.); (A.C.)
- Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, 53113 Bonn, Germany
| | - Gea Guerriero
- GreenTech Innovation Center, Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, 4362 Esch-sur-Alzette, Luxembourg; (A.G.); (G.G.); (J.R.); (J.-F.H.)
| | - Jenny Renaut
- GreenTech Innovation Center, Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, 4362 Esch-sur-Alzette, Luxembourg; (A.G.); (G.G.); (J.R.); (J.-F.H.)
| | - Stanley Lutts
- Groupe de Recherche en Physiologie Végétale, Earth and Life Institute—Agronomy, Université Catholique de Louvain, 5, Place Croix du Sud, 1348 Louvain-la-Neuve, Belgium;
| | - Saleh Alseekh
- Max-Planck-Institute of Plant Molecular Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany; (S.A.); (A.R.F.)
- Centre of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria
| | - Alisdair R. Fernie
- Max-Planck-Institute of Plant Molecular Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany; (S.A.); (A.R.F.)
- Centre of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria
| | - Jean-Francois Hausman
- GreenTech Innovation Center, Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, 4362 Esch-sur-Alzette, Luxembourg; (A.G.); (G.G.); (J.R.); (J.-F.H.)
| | - Jaco Vangronsveld
- Centre for Environmental Sciences, Campus Diepenbeek, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; (S.H.); (J.V.); (A.C.)
| | - Ann Cuypers
- Centre for Environmental Sciences, Campus Diepenbeek, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; (S.H.); (J.V.); (A.C.)
| | - Kjell Sergeant
- GreenTech Innovation Center, Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, 4362 Esch-sur-Alzette, Luxembourg; (A.G.); (G.G.); (J.R.); (J.-F.H.)
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Affiliation(s)
- W. H. O. Ernst
- Department of Ecology and Ecotoxicology, Faculty of Biology; Vrije Universiteit; De Boelelaan 1087 1081 HV Amsterdam The Netherlands
| | - J. A. C. Verkleij
- Department of Ecology and Ecotoxicology, Faculty of Biology; Vrije Universiteit; De Boelelaan 1087 1081 HV Amsterdam The Netherlands
| | - H. Schat
- Department of Ecology and Ecotoxicology, Faculty of Biology; Vrije Universiteit; De Boelelaan 1087 1081 HV Amsterdam The Netherlands
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Fernández R, Fernández-Fuego D, Bertrand A, González A. Strategies for Cd accumulation in Dittrichia viscosa (L.) Greuter: role of the cell wall, non-protein thiols and organic acids. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 78:63-70. [PMID: 24636908 DOI: 10.1016/j.plaphy.2014.02.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 02/22/2014] [Indexed: 05/27/2023]
Abstract
Dittrichia viscosa (L.) Greuter is plant species commonly found in degraded zones of Asturias (Spain), where it accumulates high levels of Cd, but the mechanisms involved in this response in non-model plants have not been elucidated. In this way, we analysed the fraction of the total Cd bound to the cell walls, the ultrastructural localization of this metal, and non-protein thiol and organic acid concentrations of two clones of D. viscosa: DV-A (from a metal-polluted soil) and DV-W (from a non-polluted area). After 10 days of hydroponic culture with Cd, fractionation and ultrastructural localisation studies showed that most of the Cd accumulated by D. viscosa was kept in the cell wall. The non-protein thiol content rose in D. viscosa with Cd exposure, especially in the non-metallicolous DV-W clone, and in both clones we found with Cd exposure a synthesis de novo of phytochelatins PC2 and PC3 in shoots and roots and also of other phytochelatin-related compounds, particularly in roots. Regarding organic acids, their concentration in both clones decreased in shoots after Cd treatment, but increased in roots, mainly due to changes in the citric acid concentration. Thus, retention of Cd in the cell wall seems to be the first strategy in response to metal entry in D. viscosa and once inside cells non-protein thiols and organic acids might also participate in Cd tolerance.
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Affiliation(s)
- R Fernández
- Departamento de Biología de Organismos y Sistemas, University of Oviedo, Catedrático Rodrigo Uría s/n, 33071 Oviedo, Spain; Instituto Universitario de Biotecnología de Asturias, Spain
| | - D Fernández-Fuego
- Departamento de Biología de Organismos y Sistemas, University of Oviedo, Catedrático Rodrigo Uría s/n, 33071 Oviedo, Spain; Instituto Universitario de Biotecnología de Asturias, Spain
| | - A Bertrand
- Departamento de Biología de Organismos y Sistemas, University of Oviedo, Catedrático Rodrigo Uría s/n, 33071 Oviedo, Spain; Instituto Universitario de Biotecnología de Asturias, Spain
| | - A González
- Departamento de Biología de Organismos y Sistemas, University of Oviedo, Catedrático Rodrigo Uría s/n, 33071 Oviedo, Spain; Instituto Universitario de Biotecnología de Asturias, Spain.
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Fernández R, Fernández-Fuego D, Rodríguez-González P, Alonso JIG, Bertrand A, González A. Cd-induced phytochelatin synthesis in Dittrichia viscosa (L.) Greuter is determined by the dilution of the culture medium. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:1133-1145. [PMID: 23881590 DOI: 10.1007/s11356-013-1954-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 06/20/2013] [Indexed: 06/02/2023]
Abstract
In this paper, we examined Cd accumulation and PC synthesis in two clones of Dittrichia viscosa, one with a metallicolous (DV-A) and the other with a non-metallicolous origin (DV-W). The clones were cultured in vitro with 0 and 10 mg Cd L(-1) in both short-term treatments (up to 72 h) and over 10 days. We also examined the influence of the culture medium dilution and the PC-synthesis inhibitor, L-buthionine-sulfoximine (BSO), on these parameters. Similar Cd accumulation values were found in the two clones. No synthesis of new thiolic compounds was observed in Cd-treated plants cultured in vitro in Murashige and Skoog medium up to 72 h when compared to controls. Dilution of the culture medium affected PC production, increasing it in 1/2 MS and especially in 1/4 MS. Cd uptake did not increase in the same way, but still hyperaccumulation levels were exceeded in all Cd treatments. BSO addition increased the sensitivity of D. viscosa to Cd and diminished Cd accumulation. Nevertheless, a poor correlation between PCs and Cd accumulation capacity was observed since the highest Cd content did not correspond to the highest PC levels. All these results obtained suggest that PCs are important in Cd accumulation and detoxification in D. viscosa and also that other mechanisms might be involved in these traits.
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Affiliation(s)
- R Fernández
- Departamento de Biología de Organismos y Sistemas, University of Oviedo, Catedrático Rodrigo Uría s/n, 33006, Oviedo, Spain
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Machado-Estrada B, Calderón J, Moreno-Sánchez R, Rodríguez-Zavala JS. Accumulation of arsenic, lead, copper, and zinc, and synthesis of phytochelatins by indigenous plants of a mining impacted area. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:3946-3955. [PMID: 23649544 DOI: 10.1007/s11356-012-1344-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 11/16/2012] [Indexed: 06/02/2023]
Abstract
Several native plants, able to grow in an unconfined mining impacted area that is now in close vicinity with urban areas, were evaluated for their ability to accumulate heavy metals. The main soil contaminants were As, Pb, Cu, and Zn. Sampling of the rhizospheric metal polluted soil showed that Euphorbia prostrata Aiton, Parthenium incanum Kunth, and Zinnia acerosa (DC.) A. Gray were able to grow in the presence of high amounts of mixtures of these elements. The plants accumulated the metals in the above ground parts and increased the synthesis of thiol molecules. E. prostrata showed the highest capacity for accumulation of the mixture of elements (588 μg g DW(-1)). Analysis of the thiol-molecules profile showed that these plants synthesized high amounts of long-chain phytochelatins, accompanied by low amounts of monothiol molecules, which may be related to their higher resistance to As and heavy metals. The three plants showed translocation factors from roots to leaves >1 for As, Pb, Cu, and Zn. Thus, by periodically removing aerial parts, these plants could be useful for the phytoremediation of semi-arid and arid mining impacted areas, in which metal hyper-accumulator plants are not able to grow.
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Affiliation(s)
- Blenda Machado-Estrada
- Departamento de Toxicología Ambiental, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
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Rehman A, Anjum MS. Multiple metal tolerance and biosorption of cadmium by Candida tropicalis isolated from industrial effluents: glutathione as detoxifying agent. ENVIRONMENTAL MONITORING AND ASSESSMENT 2011; 174:585-595. [PMID: 20499163 DOI: 10.1007/s10661-010-1480-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 04/20/2010] [Indexed: 05/29/2023]
Abstract
The ability of cadmium uptake by metal-resistant yeast, Candida tropicalis, from the liquid medium and wastewater was evaluated. The minimum inhibitory concentration of Cd(2+) against C. tropicalis was 2,500 mg L(-1). The yeast also showed tolerance toward Zn(2+) (1,400 mg L(-1)), Ni(2+) (1,000 mg L(-1)), Hg(2+) (1,400 mg L(-1)), Cu(2+) (1,000 mg L(-1)), Cr(6+) (1,200 mg L(-1)), and Pb(2+) (1,000 mg L(-1)). The yeast isolate showed typical growth curves, but lag and log phases extended in the presence of cadmium. The yeast isolate showed optimum growth at 30°C and pH 8. The metal processing ability of the isolate was determined in a medium containing 100 mg L(-1) of Cd(2+). C. tropicalis could decline Cd(2+) 70%, 85%, and 92% from the medium after 48, 96, and 144 h, respectively. C. tropicalis was also able to remove Cd(2+) 40% and 78% from the wastewater after 6 and 12 days, respectively. Cd produced an increase in glutathione (GSH) and nonprotein thiol levels by 135% and 134% at 100-mg L(-1) concentration, respectively. An increase in the synthesis of GSH is involved in metal tolerance, and the presence of increasing GSH concentrations may be a marker for high metal stress in C. tropicalis. C. tropicalis, which is resistant to heavy metal ions and is adaptable to the local environmental conditions, may be employed for metal detoxification operations.
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Affiliation(s)
- Abdul Rehman
- Department of Microbiology and Molecular Genetics, University of the Punjab, New Campus, Lahore, 54590, Pakistan.
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Rehman A, Sohail Anjum M, Hasnain S. Cadmium biosorption by yeast, Candida tropicalis CBL-1, isolated from industrial wastewater. J GEN APPL MICROBIOL 2010; 56:359-68. [DOI: 10.2323/jgam.56.359] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Qureshi MI, Qadir S, Zolla L. Proteomics-based dissection of stress-responsive pathways in plants. JOURNAL OF PLANT PHYSIOLOGY 2007; 164:1239-60. [PMID: 17662502 DOI: 10.1016/j.jplph.2007.01.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 01/05/2007] [Accepted: 01/09/2007] [Indexed: 05/16/2023]
Abstract
Abiotic stress has an ability to alter the levels of a number of proteins, which may be soluble or structural in nature or which may exist before and after folding in the plant cell. The most crucial function of plant cell is to respond to stress by developing defence mechanisms. This defence is brought about by alteration in the pattern of gene expression. This leads to modulation of certain metabolic and defensive pathways. Owing to gene expression altered under stress, qualitative and quantitative changes in proteins are obvious. These proteins might play a role in signal transduction, antioxidative defence, antifreezing, heat shock, metal binding, antipathogenesis or osmolyte synthesis. A significant part of the literature shows the quantitative and qualitative changes in proteins, mainly employing western analysis, enzymatic kinetics, fraction isolation, one-dimensional SDS-PAGE electrophoresis, etc. Fortunately, recent developments in sensitivity and accuracy for proteome analysis have provided new dimensions to assess the changes in protein types and their expression levels under stress. The novel aim of this review is to do a side-by-side comparison of the proteins that are induced or overexpressed under abiotic stress, examining those from biochemical literature and the ones observed, sequenced and identified using the advanced proteomics and bioinformatic techniques.
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Affiliation(s)
- M Irfan Qureshi
- Genomics and Proteomics Lab, Department of Environmental Sciences, University of Tuscia, Viterbo-01100, Italy.
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Gardea-Torresdey JL, Tiemann KJ, Gonzalez JH, Henning J, Townsend M. UPTAKE OF COPPER IONS FROM SOLUTION BY DIFFERENT POPULATIONS OF MEDICAGO SATIVA (ALFALFA). SOLVENT EXTRACTION AND ION EXCHANGE 2007. [DOI: 10.1080/07366299608918330] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Fenik SI, Solodushko VG, Kalinyak TB, Blume AB. The role of Cd-binding proteins and phytochelatins in the formation of resistance to cadmium in the cell lines of Nicotiana plumbaginifolia. CYTOL GENET+ 2007. [DOI: 10.3103/s0095452707010021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Avilés C, Torres-Márquez ME, Mendoza-Cózatl D, Moreno-Sánchez R. Time-course development of the Cd2+ hyper-accumulating phenotype in Euglena gracilis. Arch Microbiol 2005; 184:83-92. [PMID: 16177892 DOI: 10.1007/s00203-005-0013-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 05/05/2005] [Accepted: 05/17/2005] [Indexed: 10/25/2022]
Abstract
To determine the onset of the Cd2+-hyperaccumulating phenotype in Euglena gracilis, induced by Hg2+ pretreatment (Avilés et al. in Arch Microbiol 180:1-10, 2003), the changes in cellular growth, Cd2+ uptake, and intracellular contents of sulfide, cysteine, gamma-glutamylcysteine, glutathione and phytochelatins during the progress of the culture were analyzed. In cells exposed to 0.2 mM CdCl2, the Cd2+-hyperaccumulating phenotype was apparent only after 48 h of culture, as indicated by the significant increase in cell growth and higher internal contents of sulfide and thiol-compounds, along with a higher gamma-glutamylcysteine synthetase activity. However, the stiochiometry of thiol-compounds/Cd2+ accumulated was similar for both control and Hg2+-pretreated cells. Moreover, the value for this ratio was 2.1 or lower after 48-h culture, which does not suffice to fully inactivate Cd2+. It is concluded that, although the glutathione and phytochelatin synthesis pathway is involved in the development of the Cd2+-hyperaccumulating phenotype in E. gracilis, apparently other pathways and sub-cellular mechanisms are also involved. These may be an increase in other Cd2+ chelating molecules such as di- and tricarboxylic acids, phosphate and polyphosphates, as well as Cd2+ compartmentation into organelles.
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Affiliation(s)
- César Avilés
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Juan Badiano No. 1, Col. Sección XVI, Tlalpan, 14080, México
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Quaghebeur M, Rengel Z. Arsenic Speciation Governs Arsenic Uptake and Transport in Terrestrial Plants. Mikrochim Acta 2005. [DOI: 10.1007/s00604-005-0394-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Phytochelatins (PCs) were first discovered as Cd-binding "Cadystins A and B" in a fission yeast and then in many plants as the major components of Cd-binding complexes. PCs have the general structure of (gamma-glutamyl-cysteinyl)n-glycine (n=2-11) and the variants with the repeated gamma-glutamyl-cysteinyl units are formed in some plants and yeast. They are capable of binding to various metals including Cd, Cu, Zn or As via the sulfhydryl and carboxyl residues, but their biosyntheses are controlled preferentially by the metal Cd or metalloid As. PCs are synthesized from glutathione (gamma-glutamyl-cysteinyl-glycine) in steps mediated by PC synthase. Genes (CAD1, PCS1) of the enzyme have been isolated from plants, fission yeast and some animals. Inhibition studies of PC biosynthesis via glutathione have demonstrated their fundamental roles in the metal detoxification in yeast and fungi, green algae and some aquatic plants, and also in the suspension-cultured cells and intact tissues in higher plants. Over-expression of PC synthase genes increases the Cd-tolerance in yeast and bacteria efficiently but not always in higher plant tissues especially in metal-accumulating species. "Hyperaccumulators" of Cd, Zn, Ni or As in terrestrial plants have a common feature where massive metal transport to shoots prevails, besides the ability of their roots to form PCs. This suggests that PC-based metal detoxification might be an ancient type of defense mechanism established in micro-algae or micro-fungi, and the additional PC-independent mechanism via vascular transport system became established later in higher plants. Readjustment of the PC-dependent and independent mechanisms at the metal-binding sites in the symplast and apoplast of shoots can be effective for further improvement of the metal detoxification activities and the tolerance characteristics of higher plants under various conditions.
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Mansour MM, Kamel EAR. Interactive Effect of Heavy Metals and Gibberellic Acid on Mitotic Activity and Some Metabolic Changes of Vicia faba L. Plants. CYTOLOGIA 2005. [DOI: 10.1508/cytologia.70.275] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
| | - Ehab Abdel-Razik Kamel
- Department of Biological Sciences and Geology, Faculty of Education, Ain Shams University
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Kelly RA, Andrews JC, DeWitt JG. An X-ray absorption spectroscopic investigation of the nature of the zinc complex accumulated in Datura innoxia plant tissue culture. Microchem J 2002. [DOI: 10.1016/s0026-265x(02)00015-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Schützendübel A, Schwanz P, Teichmann T, Gross K, Langenfeld-Heyser R, Godbold DL, Polle A. Cadmium-induced changes in antioxidative systems, hydrogen peroxide content, and differentiation in Scots pine roots. PLANT PHYSIOLOGY 2001; 127:887-898. [PMID: 11706171 DOI: 10.1104/pp.010318.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To investigate whether Cd induces common plant defense pathways or unspecific necrosis, the temporal sequence of physiological reactions, including hydrogen peroxide (H(2)O(2)) production, changes in ascorbate-glutathione-related antioxidant systems, secondary metabolism (peroxidases, phenolics, and lignification), and developmental changes, was characterized in roots of hydroponically grown Scots pine (Pinus sylvestris) seedlings. Cd (50 microM, 6 h) initially increased superoxide dismutase, inhibited the systems involved in H(2)O(2) removal (glutathione/glutathione reductase, catalase [CAT], and ascorbate peroxidase [APX]), and caused H(2)O(2) accumulation. Elongation of the roots was completely inhibited within 12 h. After 24 h, glutathione reductase activities recovered to control levels; APX and CAT were stimulated by factors of 5.5 and 1.5. Cell death was increased. After 48 h, nonspecific peroxidases and lignification were increased, and APX and CAT activities were decreased. Histochemical analysis showed that soluble phenolics accumulated in the cytosol of Cd-treated roots but lignification was confined to newly formed protoxylem elements, which were found in the region of the root tip that normally constitutes the elongation zone. Roots exposed to 5 microM Cd showed less pronounced responses and only a small decrease in the elongation rate. These results suggest that in cells challenged by Cd at concentrations exceeding the detoxification capacity, H(2)O(2) accumulated because of an imbalance of redox systems. This, in turn, may have triggered the developmental program leading to xylogenesis. In conclusion, Cd did not cause necrotic injury in root tips but appeared to expedite differentiation, thus leading to accelerated aging.
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Affiliation(s)
- A Schützendübel
- Forstbotanisches Institut, Abteilung I: Forstbotanik und Baumphysiologie, Georg-August-Universität Göttingen, Büsgenweg 2, 37077 Göttingen, Germany
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19
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Schützendübel A, Schwanz P, Teichmann T, Gross K, Langenfeld-Heyser R, Godbold DL, Polle A. Cadmium-induced changes in antioxidative systems, hydrogen peroxide content, and differentiation in Scots pine roots. PLANT PHYSIOLOGY 2001; 127:887-98. [PMID: 11706171 PMCID: PMC129260 DOI: 10.1104/pp.010318] [Citation(s) in RCA: 349] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
To investigate whether Cd induces common plant defense pathways or unspecific necrosis, the temporal sequence of physiological reactions, including hydrogen peroxide (H(2)O(2)) production, changes in ascorbate-glutathione-related antioxidant systems, secondary metabolism (peroxidases, phenolics, and lignification), and developmental changes, was characterized in roots of hydroponically grown Scots pine (Pinus sylvestris) seedlings. Cd (50 microM, 6 h) initially increased superoxide dismutase, inhibited the systems involved in H(2)O(2) removal (glutathione/glutathione reductase, catalase [CAT], and ascorbate peroxidase [APX]), and caused H(2)O(2) accumulation. Elongation of the roots was completely inhibited within 12 h. After 24 h, glutathione reductase activities recovered to control levels; APX and CAT were stimulated by factors of 5.5 and 1.5. Cell death was increased. After 48 h, nonspecific peroxidases and lignification were increased, and APX and CAT activities were decreased. Histochemical analysis showed that soluble phenolics accumulated in the cytosol of Cd-treated roots but lignification was confined to newly formed protoxylem elements, which were found in the region of the root tip that normally constitutes the elongation zone. Roots exposed to 5 microM Cd showed less pronounced responses and only a small decrease in the elongation rate. These results suggest that in cells challenged by Cd at concentrations exceeding the detoxification capacity, H(2)O(2) accumulated because of an imbalance of redox systems. This, in turn, may have triggered the developmental program leading to xylogenesis. In conclusion, Cd did not cause necrotic injury in root tips but appeared to expedite differentiation, thus leading to accelerated aging.
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Affiliation(s)
- A Schützendübel
- Forstbotanisches Institut, Abteilung I: Forstbotanik und Baumphysiologie, Georg-August-Universität Göttingen, Büsgenweg 2, 37077 Göttingen, Germany
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20
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Inouhe M, Ito R, Ito S, Sasada N, Tohoyama H, Joho M. Azuki bean cells are hypersensitive to cadmium and do not synthesize phytochelatins. PLANT PHYSIOLOGY 2000; 123:1029-36. [PMID: 10889252 PMCID: PMC59066 DOI: 10.1104/pp.123.3.1029] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/1999] [Accepted: 02/21/2000] [Indexed: 05/19/2023]
Abstract
Suspension-cultured cells of azuki bean (Vigna angularis) as well as the original root tissues were hypersensitive to Cd (<10 microM). Repeated subculturings with a sublethal level of Cd (1-10 microM) did not affect the subsequent response of cells to inhibitory levels of Cd (10-100 microM). The azuki bean cells challenged to Cd did not contain phytochelatin (PC) peptides, unlike tomato (Lycopersicon esculentum) cells that have a substantial tolerance to Cd (>100 microM). Both of the cell suspensions contained a similar level of reduced glutathione (GSH) when grown in the absence of Cd. Externally applied GSH to azuki bean cells recovered neither Cd tolerance nor PC synthesis of the cells. Furthermore, enzyme assays in vitro revealed that the protein extracts of azuki bean cells had no activity converting GSH to PCs, unlike tomato. These results suggest that azuki bean cells are lacking in the PC synthase activity per se, hence being Cd hypersensitive. We concluded that the PC synthase has an important role in Cd tolerance of suspension-cultured cells.
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Affiliation(s)
- M Inouhe
- Department of Biology and Earth Science, Faculty of Science, Ehime University, Matsuyama, Ehime, 790-8577, Japan.
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21
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Gardea-Torresdey JL, Tiemann KJ, Gamez G, Dokken K. Effects of chemical competition for multi-metal binding by Medicago sativa (alfalfa). JOURNAL OF HAZARDOUS MATERIALS 1999; 69:41-51. [PMID: 10502605 DOI: 10.1016/s0304-3894(99)00057-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Alfalfa shoot biomass has demonstrated the ability to bind an appreciable amount of cadmium(II), chromium(III), copper(II), lead(II), nickel(II), and zinc(II) separately from aqueous solutions. Since most heavy metal contaminated waters contain more than one heavy metal ion, it was necessary to determine the binding abilities of the alfalfa biomass with multi-metal solutions. Batch laboratory experiments were performed with a solution containing 0.1 mM of each of the following metal ions: cadmium(II), chromium(III), copper(II), lead(II), nickel(II), and zinc(II). We determined the pH profile, time dependency, and binding capacity by the alfalfa biomass of each metal ion under multi-elemental conditions. For all the metal ions studied, the alfalfa biomass showed to have a high affinity for metal binding around pH 5.0 within a time period of approximately 5 min. The binding capacity experiments showed that there was a preferential binding of the metal ions from the multi-elemental solution with the following amounts of metal ion bound per gram of biomass: 368.5 micromol/g for copper(II), 215.4 micromol/g for chromium(III), 168.0 micromol/g for lead(II), 56.9 micromol/g for zinc(II), 49.2 micromol/g for nickel(II), and 40.3 micromol/g for cadmium(II). Reacting the biomass from the capacity experiments with 0.1 M HCl resulted in 90% or greater recovery of bound cadmium, copper, lead, nickel, and zinc. However, only 44% of the bound chromium was recovered. These experiments show the ability of Medicago sativa (alfalfa) to bind several metal ions under multi-contaminant conditions. Similar results were obtained when the experiments were performed under flow conditions using silica-immobilized alfalfa biomass. Chromium bound on the silica-immobilized biomass was also difficult to be desorbed with 0. 1 M HCl. The information obtained will be useful for the future development of an innovative technology to remove heavy metal contaminants from polluted ground waters.
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Affiliation(s)
- J L Gardea-Torresdey
- Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA.
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22
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Yen TY, Villa JA, DeWitt JG. Analysis of phytochelatin-cadmium complexes from plant tissue culture using nano-electrospray ionization tandem mass spectrometry and capillary liquid chromatography/electrospray ionization tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 1999; 34:930-41. [PMID: 10491589 DOI: 10.1002/(sici)1096-9888(199909)34:9<930::aid-jms853>3.0.co;2-e] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Phytochelatins (PCs, also known as class III metallothioneins), a family of sulfhydryl-rich peptides with the formula (gamma-GluCys)(n)Gly(Pc(n), n = 2-11), are induced in plants, yeast and fungi exposed to heavy metals, and are thought to detoxify metals by forming PC- metal complexes. Although PCs have been detected, PC- metal complexes have not been well characterized. In this work, nano-electrospray ionization tandem mass spectrometry (nano-ESI-MS/MS) and capillary liquid chromatography/electrospray ionization tandem mass spectrometry (capillary LC/ESI-MS/MS) methods were used to analyze PC - Cd complexes isolated from Datura innoxia, also known as Jimsonweed, cell culture exposed to Cd. With nano-ESI-MS/MS and capillary LC/ESI-MS/MS we could simultaneously detect the presence of PCs and PC - Cd complexes from plant cell extracts, unambiguously identify these species and elucidate the nature of individual PC - Cd complexes. Phytochelatins with n = 3-6 were detected, as were PC - Cd complexes with PC(3), PC(4) and PC(5). This is the first study to report the size and nature of native PC - Cd complexes from plant tissue samples. These results demonstrate that the direct analysis of plant extracts using nano-ESI-MS/MS and capillary LC/ESI-MS/MS methods is simple and sensitive to the range of PCs and PC - Cd complexes in plants. Hence these methods open up new opportunities for further quantitative analysis of PCs and PC - metal complexes in cell culture and plant systems to understand the relationship between the biosynthesis of these compounds and metal tolerance.
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Affiliation(s)
- T Y Yen
- Biomedical Research Mass Spectrometry Facility, Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132-4163, USA
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23
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Hesse H, Lipke J, Altmann T, Höfgen R. Molecular cloning and expression analyses of mitochondrial and plastidic isoforms of cysteine synthase (O-acetylserine(thiol)lyase) from Arabidopsis thaliana. Amino Acids 1999; 16:113-31. [PMID: 10319184 DOI: 10.1007/bf01321531] [Citation(s) in RCA: 56] [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
Cysteine synthase, the key enzyme for fixation of inorganic sulfide, catalyses the formation of cysteine from O-acetylserine and inorganic sulfide. Here we report the cloning of cDNAs encoding cysteine synthase isoforms from Arabidopsis thaliana. The isolated cDNA clones encode for a mitochondrial and a plastidic isoform of cysteine synthase (O-acetylserine (thiol)-lyase, EC 4.2.99.8), designated cysteine synthase C (AtCS-C, CSase C) and B (AtCS-B; CSase B), respectively. AtCS-C and AtCS-B, having lengths of 1569-bp and 1421-bp, respectively, encode polypeptides of 430 amino acids (approximately 45.8 kD) and of 392 amino acids (approximately 41.8 kD), respectively. The deduced amino acid sequences of the mitochondrial and plastidic isoforms exhibit high homology even with respect to the presequences. The predicted presequence of AtCS-C has a N-terminal extension of 33 amino acids when compared to the plastidic isoform. Northern blot analysis showed that AtCS-C is higher expressed in roots than in leaves whereas the expression of AtCS-B is stronger in leaves. Furthermore, gene expression of both genes was enhanced by sulfur limitation which in turn led to an increase in enzyme activity in crude extracts of plants. Expression of the AtCS-B gene is regulated by light. The mitochondrial, plastidic and cytosolic (Hesse and Altmann, 1995) isoforms of cysteine synthase of Arabidopsis are able to complement a cysteine synthase-deficient mutant of Escherichia coli unable to grow on minimal medium without cysteine, indicating synthesis of functional plant proteins in the bacterium. Two lines of evidence proved that AtCS-C encodes a mitochondrial form of cysteine synthase; first, import of in vitro translation products derived from AtCS-C in isolated intact mitochondria and second, Western blot analysis of mitochondria isolated from transgenic tobacco plants expressing AtCS-C cDNA/c-myc DNA fusion protein.
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Affiliation(s)
- H Hesse
- Institut für Genbiologische Forschung GmbH, Berlin, Federal Republic of Germany.
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24
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TIEMANN KIRKJ, GARDEA-TORRESDEY JORGEL, GAMEZ GERARDO, DOKKEN KENNETH, SIAS SALVADOR, RENNER MARKW, FURENLID LARSR. Use of X-ray Absorption Spectroscopy and Esterification to Investigate Cr(III) and Ni(II) Ligands in Alfalf a Biomass. ENVIRONMENTAL SCIENCE & TECHNOLOGY 1999; 33:150-4. [PMID: 27045146 PMCID: PMC4809208 DOI: 10.1021/es9804722] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Previously performed studies have shown that alfalfa shoot biomass can bind an appreciable amount of nickel(II) and chromium(III) ions from aqueous solution. Direct and indirect approaches were applied to study the possible mechanis ms involved in metal binding by the alfalfa biomass. The direct approach involves investigations of the metal-bound alfal fa shoot biomass by X-ray absorption spectroscopic analysis (XANES and EXAFS). Results from these studies suggest that ni ckel(II) and chromium(III) binding mostly occurs through coordination with oxygen ligands. Indirect approaches consist of chemical modification of carboxylate groups that have been shown to play an important role in metal binding to the alfal fa biomass. An appreciable decrease in metal binding resulted after acidic methanol esterification of the biomass, indica ting that carboxyl groups are entailed in the metal binding by the alfalfa biomass. In addition, base hydrolysis of the a lfalfa biomass increased the binding of these metals, which further indicates that carboxyl groups play an important role in the binding of these metal ions from solution. Therefore, by combining two different techniques, our results indicate that carboxylate groups are the major ligands responsible for the binding of nickel(II) and chromium(III) by alfalfa bio mass.
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25
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Kuske CR, Hill KK, Guzman E, Jackson PJ. Subcellular Location of O-Acetylserine Sulfhydrylase Isoenzymes in Cell Cultures and Plant Tissues of Datura innoxia Mill. PLANT PHYSIOLOGY 1996; 112:659-667. [PMID: 12226419 PMCID: PMC157990 DOI: 10.1104/pp.112.2.659] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
O-Acetylserine sulfhydrylase (OASS; EC 4.2.99.8) catalyzes the formation of L-cysteine from O-acetylserine and inorganic sulfide. Three OASS isoenzymes that differ in molecular mass and subunit structure are present in shoot and root tissues and in cadmium-resistant and cadmium-susceptible cell cultures of Datura innoxia Mill. Different OASS forms predominate in leaves, roots, and suspension-cell cultures. To determine the subcellular location of the OASS isoenzymes, purified mitochondria, chloroplasts, and cytosolic fractions from protoplasts were obtained. The isoenzymes are compartmentalized in D. innoxia cells, with a different isoenzyme predominant in the chloroplast, cytosol, and mitochondria, suggesting that they serve different functions in the plant cell. The chloroplast form is most abundant in green leaves and leaf protoplasts. The cytosolic form is most abundant in roots and cell cultures. A mitochondrial form is abundant in cell cultures, but is a minor form in leaves or roots. Cadmium-tolerant cell cultures contain 1.8 times as much constitutive OASS activity as the wild-type cell line, and 2.9 times more than the cadmium-hypersensitive cell line. This may facilitate rapid production of glutathione and metal-binding phytochelatins when these cultures are exposed to cadmium.
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Affiliation(s)
- C. R. Kuske
- Environmental Molecular Biology Group, M888, Life Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
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26
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Maitani T, Kubota H, Sato K, Yamada T. The Composition of Metals Bound to Class III Metallothionein (Phytochelatin and Its Desglycyl Peptide) Induced by Various Metals in Root Cultures of Rubia tinctorum. PLANT PHYSIOLOGY 1996; 110:1145-1150. [PMID: 12226248 PMCID: PMC160897 DOI: 10.1104/pp.110.4.1145] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The induction of phytochelatins (PCs) and their desglycyl peptides (both are referred to as class III metallothionein [CIIIMT]) by exposure to various metals (Ag+, As3+, As5+, Cd2+, Cu2+, Ga3+, Hg2+, In3+, Ni2+, Pb2+, Pd2+, Se4+, and Zn2+) and the metal composition in the CIIIMTs were investigated in root cultures of Rubia tinctorum L. All of these metal species induced PCs to various degrees when analyzed by the postcolumn derivatization high-performance liquid chromatography method. The desglycyl peptides of PCs often were also present. However, only Ag, Cd, and Cu were bound to the CIIIMTs that they induced when analyzed by the high-performance liquid chromatography-inductively coupled plasma-atomic emission spectrometry method. Cu was also bound to the CIIIMTs induced by Ag+, As3+, and Cd2+. After Ag+ exposure, an Fe peak that may be of Fe-CIIIMT was also observed. However, most of the metal species studied were not bound to the CIIIMTs that they induced.
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Affiliation(s)
- T. Maitani
- National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya, Tokyo 158, Japan
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27
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Krämer U, Cotter-Howells JD, Charnock JM, Baker AJM, Smith JAC. Free histidine as a metal chelator in plants that accumulate nickel. Nature 1996. [DOI: 10.1038/379635a0] [Citation(s) in RCA: 666] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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28
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Howden R, Goldsbrough PB, Andersen CR, Cobbett CS. Cadmium-sensitive, cad1 mutants of Arabidopsis thaliana are phytochelatin deficient. PLANT PHYSIOLOGY 1995; 107:1059-66. [PMID: 7770517 PMCID: PMC157237 DOI: 10.1104/pp.107.4.1059] [Citation(s) in RCA: 278] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
An allelic series of cad1, cadmium-sensitive mutants of Arabidopsis thaliana, was isolated. These mutants were sensitive to cadmium to different extents and were deficient in their ability to form cadmium-peptide complexes as detected by gel-filtration chromatography. Each mutant was deficient in its ability to accumulate phytochelatins (PCs) as detected by high-performance liquid chromatography and the amount of PCs accumulated by each mutant correlated with its degree of sensitivity to cadmium. The mutants had wild-type levels of glutathione, the substrate for PC biosynthesis, and in vitro assays demonstrated that each of the mutants was deficient in PC synthase activity. These results demonstrate conclusively the importance of PCs for cadmium tolerance in plants.
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Affiliation(s)
- R Howden
- Department of Genetics, University of Melbourne, Australia
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29
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Klapheck S, Schlunz S, Bergmann L. Synthesis of Phytochelatins and Homo-Phytochelatins in Pisum sativum L. PLANT PHYSIOLOGY 1995; 107:515-521. [PMID: 12228379 PMCID: PMC157155 DOI: 10.1104/pp.107.2.515] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In the roots of pea plants (Pisum sativum L.) cultivated with 20 [mu]M CdCl2 for 3 d, synthesis of phytochelatins [PCs or ([gamma]EC)nG, where [gamma]EC is [gamma]glutamylcysteine and G is glycine] and homophytochelatins [h-PCs, ([gamma]EC)n[beta]-alanine] is accompanied by a drastic decrease in glutathione (GSH) content, but an increase in homoglutathione (h-GSH) content. In contrast, the in vitro activity of GSH synthetase increases 5-fold, whereas h-GSH synthetase activity increases regardless of Cd exposure. The consititutive enzyme PC synthase, which catalyzes the transfer of the [gamma]-EC moiety of GSH to an acceptor GSH molecule thus producing ([gamma]EC)2G, is activated by heavy metals, with Cd and Cu being strong activators and Zn being a very poor activator. Using h-GSH or hm-GSH for substrate, the synthesis rate of([gamma]EC)2[beta]-alanine and [gamma]EC)2-serine is only 2.4 and 0.3%, respectively, of the sythesis rate of ([gamma]EC)2G with GSH as substrate. However, in the presence of a constant GSH level, increasing the concentration of h-GSH or hm-GSH results in increased synthesis of ([gamma]EC)2[beta]-alanine or ([gamma]EC)2-serine, respecively; simultaneously, the synthesis of ([gamma]EC)2G is inhibited. [gamma]EC is not a substrate of PC synthase. These results are best explained by assuming that PC synthase has a [gamma]EC donor binding site, which is very specific for GSH, and a [gamma]EC acceptor binding site, which is less specific and accepts several tripeptides, namely GSH, h-GSH, and hm-GSH.
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Affiliation(s)
- S. Klapheck
- Botanical Institute, University of Cologne, D-50923 Cologne, Germany
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30
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Purification and characterization of O-acetylserine sulfhydrylase isoenzymes from Datura innoxia. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37591-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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31
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De Knecht JA, Van Dillen M, Koevoets PLM, Schat H, Verkleij JAC, Ernst WHO. Phytochelatins in Cadmium-Sensitive and Cadmium-Tolerant Silene vulgaris (Chain Length Distribution and Sulfide Incorporation). PLANT PHYSIOLOGY 1994; 104:255-261. [PMID: 12232077 PMCID: PMC159184 DOI: 10.1104/pp.104.1.255] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In response to a range of Cd concentrations, the root tips of Cd-tolerant plants of Silene vulgaris exhibit a lower rate of PC production accompanied by a lower rate of longer chain PC synthesis than those of Cd-sensitive plants. At the same Cd exposure level, stable PC-Cd complexes are more rapidly formed in the roots of Cd-sensitive plants than in those of tolerant plants. At an equal PC concentration in the roots, the PC composition and the amount of sulfide incorporated per unit of PC-thiol is the same in both populations. Although these compounds might play some role in mechanisms that contribute to Cd detoxification, the ability to produce these compounds in greater amounts is not, itself, the mechanism that produces increased Cd tolerance in tolerant S. vulgaris plants.
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Affiliation(s)
- J. A. De Knecht
- Department of Ecology and Ecotoxicology, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
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32
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Harmens H, Den Hartog PR, Bookum WMT, Verkleij JAC. Increased Zinc Tolerance in Silene vulgaris (Moench) Garcke Is Not Due to Increased Production of Phytochelatins. PLANT PHYSIOLOGY 1993; 103:1305-1309. [PMID: 12232023 PMCID: PMC159120 DOI: 10.1104/pp.103.4.1305] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The concentration of acid-soluble thiols other than reduced glutathione (SH - GSH) increases in the roots of zinc-sensitive and zinc-tolerant Silene vulgaris (Moench) Garcke after exposure to zinc for 1 to 3 d. The concentration of SH - GSH in the roots is higher in the sensitive plants than in the tolerant ones, both at equal external zinc concentrations and at zinc concentrations causing the same level of root-length growth inhibition. High performance liquid chromatography analyses show that the increase in the concentration of SH - GSH is not only due to the production of phytochelatins, but is also due to an increase in the concentration of cysteine and the production of nonidentified thiols. The cysteine concentration increases equally in the roots of sensitive and tolerant plants. The accumulation of phytochelatins is higher in the roots of the sensitive plants, whereas the chain length distribution of phytochelatins is the same in sensitive and tolerant plants. It is concluded that increased zinc tolerance in S. vulgaris is not due to increased production of phytochelatins.
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Affiliation(s)
- H. Harmens
- Department of Ecology and Ecotoxicology, Faculty of Biology, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
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33
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Affiliation(s)
- N J Robinson
- Department of Biological Sciences, University of Durham, U.K
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34
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Schat H, Kalff MM. Are phytochelatins involved in differential metal tolerance or do they merely reflect metal-imposed strain? PLANT PHYSIOLOGY 1992; 99:1475-80. [PMID: 16669061 PMCID: PMC1080650 DOI: 10.1104/pp.99.4.1475] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Plants from nontolerant and copper-tolerant populations of Silene vulgaris both produce phytochelatins upon exposure to copper. The threshold copper concentration for induction of phytochelatin and the copper concentration at which maximum phytochelatin contents occurs increase proportionally with the level of tolerance to copper. When exposed to their own highest no-effect concentration or 50%-effect concentration of copper for root growth, tolerant and nontolerant plants exhibit equal phytochelatin contents in the root apex, which is the primary copper target. This also holds for distinctly tolerant nonsegregating F(3) families, derived from a single cross of a nontolerant plant to a tolerant one. Therefore, the phytochelatin content of the root apex can be used as a quantitative tolerance-independent measure of the degree of toxicity experienced by the plant. Differential copper tolerance in S. vulgaris does not appear to rely on differential phytochelatin production.
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Affiliation(s)
- H Schat
- Department Ecology and Ecotoxicology, Faculty of Biology, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
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35
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Rüegsegger A, Brunold C. Effect of Cadmium on gamma-Glutamylcysteine Synthesis in Maize Seedlings. PLANT PHYSIOLOGY 1992; 99:428-33. [PMID: 16668902 PMCID: PMC1080479 DOI: 10.1104/pp.99.2.428] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Cysteine, gamma-glutamylcysteine, and glutathione and the extractable activity of the enzymes of glutathione biosynthesis, gamma-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione synthetase (EC 6.3.2.3), were measured in roots and leaves of maize seedlings (Zea mays L. cv LG 9) exposed to CdCl(2) concentrations up to 200 micromolar. At 50 micromolar Cd(2+), gamma-glutamylcysteine contents increased continuously during 4 days up to 21-fold and eightfold of the control in roots and leaves, respectively. Even at 0.5 micromolar Cd(2+), the concentration of gamma-glutamylcysteine in the roots was significantly higher than in the control. At 5 micromolar and higher Cd(2+) concentrations, a significant increase in gamma-glutamylcysteine synthetase activity was measured in the roots, whereas in the leaves this enzyme activity was enhanced only at 200 micromolar Cd(2+). Labeling of isolated roots with [(35)S]sulfate showed that both sulfate assimilation and glutathione synthesis were increased by Cd. The accumulation of gamma-glutamylcysteine in the roots did not affect the root exudation rate of this compound. Our results indicate that maize roots are at least in part autonomous in providing the additional thiols required for phytochelatin synthesis induced by Cd.
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Affiliation(s)
- A Rüegsegger
- Pflanzenphysiologisches Institut der Universität Bern, Altenbergrain 21, 3013 Bern, Switzerland
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36
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De Vos CH, Vonk MJ, Vooijs R, Schat H. Glutathione Depletion Due to Copper-Induced Phytochelatin Synthesis Causes Oxidative Stress in Silene cucubalus. PLANT PHYSIOLOGY 1992; 98:853-8. [PMID: 16668756 PMCID: PMC1080279 DOI: 10.1104/pp.98.3.853] [Citation(s) in RCA: 216] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The relation between loss of glutathione due to metal-induced phytochelatin synthesis and oxidative stress was studied in the roots of copper-sensitive and tolerant Silene cucubalus (L.) Wib., resistant to 1 and 40 micromolar Cu, respectively. The amount of nonprotein sulfhydryl compounds other than glutathione was taken as a measure of phytochelatins. At a supply of 20 micromolar Cu, which is toxic for sensitive plants only, phytochelatin synthesis and loss of total glutathione were observed only in sensitive plants within 6 h of exposure. When the plants were exposed to a range of copper concentrations for 3 d, a marked production of phytochelatins in sensitive plants was already observed at 0.5 micromolar Cu, whereas the production in tolerant plants was negligible at 40 micromolar or lower. The highest production in tolerant plants was only 40% of that in sensitive plants. In both varieties, the synthesis of phytochelatins was coupled to a loss of glutathione. Copper at toxic concentrations caused oxidative stress, as was evidenced by both the accumulation of lipid peroxidation products and a shift in the glutathione redox couple to a more oxidized state. Depletion of glutathione by pretreatment with buthionine sulfoximine significantly increased the oxidative damage by copper. At a comparably low glutathione level, cadmium had no effect on either lipid peroxidation or the glutathione redox couple in buthionine sulfoximine-treated plants. These results indicate that copper may specifically cause oxidative stress by depletion of the antioxidant glutathione due to phytochelatin synthesis. We conclude that copper tolerance in S. cucubalus does not depend on the production of phytochelatins but is related to the plant's ability to prevent glutathione depletion resulting from copper-induced phytochelatin production, e.g. by restricting its copper uptake.
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Affiliation(s)
- C H De Vos
- Department of Ecology and Ecotoxicology, Free University of Amsterdam, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
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Howe G, Merchant S. Heavy Metal-Activated Synthesis of Peptides in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 1992; 98:127-36. [PMID: 16668603 PMCID: PMC1080159 DOI: 10.1104/pp.98.1.127] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
In this study, we have addressed the capacity of the green alga Chlamydomonas reinhardtii to produce metal-binding peptides in response to stress induced by the heavy metals Cd(2+), Hg(2+), and Ag(+). Cells cultured in the presence of sublethal concentrations of Cd(2+) synthesized and accumulated oligopeptides consisting solely of glutamic acid, cysteine, and glycine in an average ratio of 3:3:1. Cadmium-induced peptides were isolated in their native form as higher molecular weight peptide-metal complexes with an apparent molecular weight of approximately 6.5 x 10(3). The isolated complex bound cadmium (as evidenced by absorption spectroscopy) and sequestered (with a stoichiometry of 0.7 moles of cadmium per mole of cysteine) up to 70% of the total cadmium found in extracts of cadmium-treated cells. In Hg(2+)-treated cells, the principal thiol-containing compound induced by Hg(2+) ions was glutathione. It is possible that glutathione functions in plant cells (as it does in animal cells) to detoxify heavy metals. Cells treated with Ag(+) ions also synthesized a sulfur-containing component with a charge to mass ratio similar to Cd(2+)-induced peptides. But, in contrast to the results obtained using Cd(2+) as an inducer, these molecules did not accumulate to significant levels in Ag(+)-treated cells. The presence of physiological concentrations of Cu(2+) in the growth medium blocked the synthesis of the Ag(+)-inducible component(s) and rendered cells resistant to the toxic effects of Ag(+), suggesting competition between Cu(2+) and Ag(+) ions, possibly at the level of metal uptake.
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Affiliation(s)
- G Howe
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90024
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Gupta SC, Goldsbrough PB. Phytochelatin accumulation and cadmium tolerance in selected tomato cell lines. PLANT PHYSIOLOGY 1991; 97:306-12. [PMID: 16668386 PMCID: PMC1080998 DOI: 10.1104/pp.97.1.306] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Four cell lines of tomato, Lycopersicon esculentum Mill. cv VFNT-Cherry, were selected for their ability to grow in the presence of up to 6 millimolar CdCl(2). The intracellular Cd concentration in these cells was at least 2.3 times higher than in the medium. Growth in media containing higher concentrations of Cd was accompanied by increased production of Cd-binding phytochelatins and a trend toward accumulation of higher molecular weight phytochelatins. At least 90% of the Cd in the most tolerant cells was associated with Cd-phytochelatin complexes. Cell lines maintained an increased tolerance of Cd in the absence of continuous selection pressure.
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Affiliation(s)
- S C Gupta
- Department of Horticulture, Purdue University, West Lafayette, Indiana 47907
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Mutoh N, Kawabata M, Hayashi Y. Tetramethylthiuram disulfide or dimethyldithiocarbamate induces the synthesis of cadystins, heavy metal chelating peptides, in Schizosaccharomyces pombe. Biochem Biophys Res Commun 1991; 176:1068-73. [PMID: 1645536 DOI: 10.1016/0006-291x(91)90392-k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Tetramethylthiuram disulfide (TMTD) or dimethyldithiocarbamate (DMDTC) induces the synthesis of cadystins, a family of heavy metal chelating isopeptides with the formula (gamma-Glu-Cys)n-Gly (n = 2,3,4,...), in the fission yeast Schizosaccharomyces pombe. Amount of cadystins synthesized in TMTD or DMDTC treated cells is less than that synthesized in CdCl2 treated cells but much more than that synthesized in ZnCl2 or CuSO4 treated cells.
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Affiliation(s)
- N Mutoh
- Department of Genetics, Institute for Developmental Research, Aichi Prefectural Colony, Japan
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Changes in metal-binding peptides due to acclimation to cadmium transferred between ramets of Salvinia minima. Oecologia 1991; 88:109-115. [DOI: 10.1007/bf00328410] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/1990] [Accepted: 05/17/1991] [Indexed: 11/25/2022]
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Gupta SC, Goldsbrough PB. Phytochelatin accumulation and stress tolerance in tomato cells exposed to cadmium. PLANT CELL REPORTS 1990; 9:466-469. [PMID: 24227180 DOI: 10.1007/bf00232275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/1990] [Revised: 10/18/1990] [Indexed: 06/02/2023]
Abstract
Cell suspension cultures of tomato (Lycopersicon esculentum) adapted to growing continuously in the presence of 0.1 mM CdCl2 and accumulated phytochelatins (PCs, poly(γ-Glu-Cys)n-Gly). The highest level of PCs was measured 4 days after inoculation and coincided with the peak of cellular cadmium concentration. At this time there was an 8-fold molar excess of PC (γ-Glu-Cys) over Cd. PCs could not be detected after 12 days when the cellular concentration of cadmium was 0.2 mM. These results indicate that PCs are produced in excess of that required to bind the cellular cadmium in the early stage of the culture period followed by degradation of PCs during the stationary phase. Adaptation to 0.1 mM CdCl2 did not increase tolerance to higher concentrations of cadmium when compared with control cells, but did significantly enhance tolerance to both anaerobiosis and heat shock. Exposure of tomato cells to 0.1 mM CdCl2 resulted in several changes in proteins synthesized.
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Affiliation(s)
- S C Gupta
- Department of Horticulture, Purdue University, 47907, West Lafayette, IN, USA
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Vögeli-Lange R, Wagner GJ. Subcellular localization of cadmium and cadmium-binding peptides in tobacco leaves : implication of a transport function for cadmium-binding peptides. PLANT PHYSIOLOGY 1990; 92:1086-93. [PMID: 16667375 PMCID: PMC1062420 DOI: 10.1104/pp.92.4.1086] [Citation(s) in RCA: 206] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The synthesis of Cd-binding peptides (CdBPs) was induced upon addition of 20 micromolar CdCl(2) (nonphytotoxic level) to the nutrient solution of hydroponically grown tobacco seedlings (Nicotiana rustica var Pavonii). Amino acid analysis showed that the main components were gamma-(Glu-Cys)(3)-Gly and gamma-(Glu-Cys)(4)-Gly. Seedlings exposed to the metal for 1 week contained similar glutathione levels as found in the controls (about 0.18 micromole per gram fresh weight). If, as has been proposed, CdBPs are involved in Cd-detoxification by chelation, both metal and ligand must be localized in the same cellular compartment. To directly determine the localization of Cd and CdBPs, protoplasts and vacuoles were isolated from leaves of Cd-exposed seedlings. Purified vacuoles contained virtually all of the CdBPs and Cd found in protoplasts (104% +/- 8 and 110% +/- 8, respectively). CdBPs were associated with the vacuolar sap and not with the tonoplast membrane. Glutathione was observed in leaves and protoplasts but not in vacuoles. The probability that CdBPs are synthesized extravacuolarly and our finding that they and Cd are predominantly located in the vacuole suggest that these molecules might be involved in transport of Cd to the vacuole. Our results also suggest that a simple cytoplasmic chelator role for CdBPs in Cd tolerance cannot be assumed.
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Affiliation(s)
- R Vögeli-Lange
- Plant Physiology/Biochemistry/Molecular Biology Program, Department of Agronomy, University of Kentucky, Lexington, Kentucky 40546-0091
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Favero N, Costa P, Rocco G. Role of copper in cadmium metabolism in the basidiomycetes Pleurotus ostreatus. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0742-8413(90)90145-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Delhaize E, Robinson NJ, Jackson PJ. Effects of cadmium on gene expression in cadmium-tolerant and cadmium-sensitiveDatura innoxia cells. PLANT MOLECULAR BIOLOGY 1989; 12:487-497. [PMID: 24271065 DOI: 10.1007/bf00036963] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/1988] [Accepted: 01/09/1989] [Indexed: 06/02/2023]
Abstract
The effect of Cd on gene expression in suspension cultures of twoDatura innoxia cell lines with differing Cd tolerance was studied.In vivo labeling experiments using [(3)H] leucine showed that Cd induced the synthesis of a similar range of proteins in both cell lines at a concentration which will kill the sensitive but not the tolerant cells. Corresponding changes in levels of translatable mRNA were also observed. The induction of the synthesis of proteins by Cd was transient since Cd-tolerant cells growing continuously in 250 μM CdCl2 contained a similar set ofin vitro translation products to cells growing in the absence of Cd. Although Cd had a similar effect on gene expression in both cell lines, Cd-tolerant cells possess two abundant mRNAs which are constitutively produced. These mRNAs encode proteins of low molecular weight (about 11 kDa) and are either absent or present at a low level in Cd-sensitive cells. The functions of these proteins are not known but they may be involved in the tolerance mechanism. Two-dimensional gel electrophoresis ofin vitro translation products showed that many of the Cd-induced proteins are also induced by heat shock. A 42°C heat shock resulted in agreater range and more intense induction of translatable mRNAs than 4 h exposure to 250 μM CdCl2. However a subset of mRNAs were induced specifically by Cd while other mRNAs were heat shock-specific. There was no difference in the ability of the two cell lines to tolerate heat shock. This was also reflected by the same pattern of major proteins induced by heat shock in the two cell lines.
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Affiliation(s)
- E Delhaize
- Genetics Group, Life Sciences Division, Los Alamos National Laboratory, Mail Stop M886, 87545, Los Alamos, New Mexico, USA
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