801
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Dietrich P, Anschütz U, Kugler A, Becker D. Physiology and biophysics of plant ligand-gated ion channels. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12 Suppl 1:80-93. [PMID: 20712623 DOI: 10.1111/j.1438-8677.2010.00362.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Small molecules and metabolites often act as intra- or extracellular messengers in signal transduction pathways. Ligand-gated ion channels provide a mean to transduce those biochemical signals at the membrane into electrical events and ion fluxes. In plants, cyclic nucleotides and glutamate represent intra- and extracellular signalling ligands, respectively. While the former have been shown to regulate voltage-dependent ion channels and are supposed to activate cyclic nucleotide gated (CNG) channels, the latter are perceived by ionotropic glutamate receptors (GLRs). This review summarises our current knowledge about CNG channels and glutamate receptors in plants and their proposed roles in plant development and adaptation to biotic and abiotic stresses.
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Affiliation(s)
- P Dietrich
- Department of Biology, Erlangen University, Erlangen, Germany.
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802
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Deng X, Xia Y, Hu W, Zhang H, Shen Z. Cadmium-induced oxidative damage and protective effects of N-acetyl-L-cysteine against cadmium toxicity in Solanum nigrum L. JOURNAL OF HAZARDOUS MATERIALS 2010; 180:722-729. [PMID: 20488618 DOI: 10.1016/j.jhazmat.2010.04.099] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 04/21/2010] [Accepted: 04/23/2010] [Indexed: 05/29/2023]
Abstract
The effects of cadmium (Cd) on the accumulation of hydrogen peroxide (H(2)O(2)) and antioxidant enzyme activities in roots of Solanum nigrum L. and the role of N-acetyl-l-cysteine (NAC) as a cysteine (Cys) donor against Cd toxicity were investigated. Cd at 50 and 200 microM significantly increased the contents of thiobarbituric acid-reactive substances (TBARS), the production of H(2)O(2) and superoxide anion (O(2)(-)), and the activities of catalase, guaiacol peroxidase, ascorbate peroxidase, glutathione peroxidase (GSH-Px), glutathione reductase, and superoxide dismutase. Experiments with diphenylene iodonium as an inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and NaN(3) as an inhibitor of peroxidase showed that the major source of Cd-induced reactive oxygen species in the roots may include plasma membrane-bound NADPH oxidase and peroxidase. In addition, the effects of NAC on plant growth, antioxidant enzyme activity, and non-protein thiol content were analyzed. Under Cd stress, the addition of 500 microM NAC decreased the contents of TBARS and production of H(2)O(2) and O(2)(-), but increased levels of Cys and reduced glutathione (GSH), phytochelatins, and activity of GSH-Px in roots. These results suggest that NAC could protect plants from oxidative stress damage, and this protection seems to be performed via increased GSH biosynthesis. Furthermore, NAC treatment also increased the contents of protein thiols in S. nigrum roots. By using size-exclusion chromatography, we found involvement of NAC in the Cd tolerance mechanism through increased biosynthesis of Cd-binding proteins.
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Affiliation(s)
- Xiaopeng Deng
- College of Life Sciences, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China
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803
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Tian S, Lu L, Yang X, Webb SM, Du Y, Brown PH. Spatial imaging and speciation of lead in the accumulator plant Sedum alfredii by microscopically focused synchrotron X-ray investigation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:5920-6. [PMID: 20608726 DOI: 10.1021/es903921t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Sedum alfredii (Crassulaceae), a species native to China, has been characterized as a Zn/Cd cohyperaccumulator and Pb accumulator though the mechanisms of metal tolerance and accumulation are largely unknown. Here, the spatial distribution and speciation of Pb in tissues of the accumulator plant was investigated using synchrotron-based X-ray microfluorescence and powder Extended X-ray absorption fine structure (EXAFS) spectroscopy. Lead was predominantly restricted to the vascular bundles of both leaf and stem of the accumulator. Micro-XRF analysis revealed that Pb distributed predominantly within the areas of vascular bundles, and a positive correlation between the distribution patterns of S and Pb was observed. The dominant chemical form of Pb (>60%) in tissues of both accumulating (AE) and nonaccumulating ecotype (NAE) S. alfredii was similar to prepared Pb-cell wall compounds. However, the percentage of the Pb-cell wall complex is lower in the stem and leaf of AE, and a small amount of Pb appeared to be associated with SH-compounds. These results suggested a very low mobility of Pb out of vascular bundles, and that the metal is largely retained in the cell walls during transportation in plants of S. alfredii.
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Affiliation(s)
- Shengke Tian
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Science, Zhejiang University, Hangzhou 310029, China
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804
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Kalinowska R, Pawlik-Skowrońska B. Response of two terrestrial green microalgae (Chlorophyta, Trebouxiophyceae) isolated from Cu-rich and unpolluted soils to copper stress. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2010; 158:2778-85. [PMID: 20605295 DOI: 10.1016/j.envpol.2010.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 02/27/2010] [Accepted: 03/02/2010] [Indexed: 05/09/2023]
Abstract
Some algae inhabit Cu-polluted soils. Intracellular Cu-accumulation and production of non-protein thiols in response to copper stress were compared in Stichococcus minor and Geminella terricola isolated from Cu-polluted and unpolluted soils, respectively. Cu-exposed (0.5 microM) S. minor accumulated lower amounts of copper (0.38 mM) than G. terricola (4.20 mM) and maintained 8.5-fold higher level of glutathione (GSH) than G. terricola. The ratio GSH/0.5 GSSG in the Cu-treated S. minor (7.21) was 7-times higher than in G. terricola. Reduced and oxidized forms of phytochelatins were found in both algae. Under copper stress (5 microM) the ratio -SH(total)/Cu(intracellular) in S. minor ranged from 2.3 to 6.2, while it was lower than 1.0 in G. terricola. Low intracellular Cu-accumulation and maintenance of high GSH level concomitant with PCs production seem to be responsible for a higher Cu-resistance of S. minor than G. terricola.
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Affiliation(s)
- Renata Kalinowska
- Centre for Ecological Research, Polish Academy of Sciences, Experimental Station, Niecała18/3, 20-080 Lublin, Poland.
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805
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Song WY, Choi KS, Kim DY, Geisler M, Park J, Vincenzetti V, Schellenberg M, Kim SH, Lim YP, Noh EW, Lee Y, Martinoia E. Arabidopsis PCR2 is a zinc exporter involved in both zinc extrusion and long-distance zinc transport. THE PLANT CELL 2010; 22:2237-52. [PMID: 20647347 PMCID: PMC2929092 DOI: 10.1105/tpc.109.070185] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 06/13/2010] [Accepted: 07/01/2010] [Indexed: 05/19/2023]
Abstract
Plants strictly regulate the uptake and distribution of Zn, which is essential for plant growth and development. Here, we show that Arabidopsis thaliana PCR2 is essential for Zn redistribution and Zn detoxification. The pcr2 loss-of-function mutant was compromised in growth, both in Zn-excessive and -deficient conditions. The roots of pcr2 accumulated more Zn than did control plants, whereas the roots of plants overexpressing PCR2 contained less Zn, indicating that PCR2 removes Zn from the roots. Consistent with a role for PCR2 as a Zn-efflux transporter, PCR2 reduced the intracellular concentration of Zn when expressed in yeast cells. PCR2 is located mainly in epidermal cells and in the xylem of young roots, while it is expressed in epidermal cells in fully developed roots. Zn accumulated in the epidermis of the roots of pcr2 grown under Zn-limiting conditions, whereas it was found in the stele of wild-type roots. The transport pathway mediated by PCR2 does not seem to overlap with that mediated by the described Zn translocators (HMA2 and HMA4) since the growth of pcr2 hma4 double and pcr2 hma2 hma4 triple loss-of-function mutants was more severely inhibited than the individual single knockout mutants, both under conditions of excess or deficient Zn. We propose that PCR2 functions as a Zn transporter essential for maintaining an optimal Zn level in Arabidopsis.
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Affiliation(s)
- Won-Yong Song
- Institut für Pflanzenbiologie, Universität Zürich, 8008 Zurich, Switzerland.
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806
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Frérot H, Faucon MP, Willems G, Godé C, Courseaux A, Darracq A, Verbruggen N, Saumitou-Laprade P. Genetic architecture of zinc hyperaccumulation in Arabidopsis halleri: the essential role of QTL x environment interactions. THE NEW PHYTOLOGIST 2010; 187:355-367. [PMID: 20487314 DOI: 10.1111/j.1469-8137.2010.03295.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
This study sought to determine the main genomic regions that control zinc (Zn) hyperaccumulation in Arabidopsis halleri and to examine genotype x environment effects on phenotypic variance. To do so, quantitative trait loci (QTLs) were mapped using an interspecific A. halleri x Arabidopsis lyrata petraea F(2) population. *The F(2) progeny as well as representatives of the parental populations were cultivated on soils at two different Zn concentrations. A linkage map was constructed using 70 markers. *In both low and high pollution treatments, zinc hyperaccumulation showed high broad-sense heritability (81.9 and 74.7%, respectively). Five significant QTLs were detected: two QTLs specific to the low pollution treatment (chromosomes 1 and 4), and three QTLs identified at both treatments (chromosomes 3, 6 and 7). These QTLs explained 50.1 and 36.5% of the phenotypic variance in low and high pollution treatments, respectively. Two QTLs identified at both treatments (chromosomes 3 and 6) showed significant QTL x environment interactions. *The QTL on chromosome 3 largely colocalized with a major QTL previously identified for Zn and cadmium (Cd) tolerance. This suggests that Zn tolerance and hyperaccumulation share, at least partially, a common genetic basis and may have simultaneously evolved on heavy metal-contaminated soils.
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Affiliation(s)
- Hélène Frérot
- Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, Université des Sciences et Technologies de Lille - Lille1, F-59655 Villeneuve d'Ascq Cedex, France
| | - Michel-Pierre Faucon
- Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, Université des Sciences et Technologies de Lille - Lille1, F-59655 Villeneuve d'Ascq Cedex, France
| | - Glenda Willems
- Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, Université des Sciences et Technologies de Lille - Lille1, F-59655 Villeneuve d'Ascq Cedex, France
| | - Cécile Godé
- Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, Université des Sciences et Technologies de Lille - Lille1, F-59655 Villeneuve d'Ascq Cedex, France
| | - Adeline Courseaux
- Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, Université des Sciences et Technologies de Lille - Lille1, F-59655 Villeneuve d'Ascq Cedex, France
| | - Aude Darracq
- Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, Université des Sciences et Technologies de Lille - Lille1, F-59655 Villeneuve d'Ascq Cedex, France
| | - Nathalie Verbruggen
- Laboratoire de Physiologie et de Génétique Moléculaire des Plantes, Université Libre de Bruxelles, Campus de la Plaine, CP242, boulevard du Triomphe, 1050 Bruxelles, Belgium
| | - Pierre Saumitou-Laprade
- Laboratoire de Génétique et Evolution des Populations Végétales, UMR CNRS 8016, Université des Sciences et Technologies de Lille - Lille1, F-59655 Villeneuve d'Ascq Cedex, France
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807
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Qureshi MI, D'Amici GM, Fagioni M, Rinalducci S, Zolla L. Iron stabilizes thylakoid protein-pigment complexes in Indian mustard during Cd-phytoremediation as revealed by BN-SDS-PAGE and ESI-MS/MS. JOURNAL OF PLANT PHYSIOLOGY 2010; 167:761-770. [PMID: 20199821 DOI: 10.1016/j.jplph.2010.01.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 12/30/2009] [Accepted: 01/05/2010] [Indexed: 05/28/2023]
Abstract
Two-dimensional BN-SDS-PAGE, ESI-MS/MS and electron microscopy (EM) were used to study the role of iron (Fe) under cadmium (Cd) stress in retention of thylakoidal multiprotein complexes (MPCs) and chloroplast ultrastructure of Indian mustard, a moderate hyperaccumulator plant. Mustard was grown hydroponically with or without iron for 17 days and then exposed to CdCl2 for 3 days. Fe deficiency led to an increase in oxidative stress and damage to chloroplast/thylakoids accompanied by a decrease in chlorophyll content; exposure of plants to Cd further enhanced the oxidative stress and Cd accumulation (more in -Fe plants). However, the presence of iron aided plants in the suppression of oxidative stress and retention of chloroplasts and chlorophylls under Cd stress. Proteomic analyses by 2D BN-SDS-PAGE and mass spectrometry showed that Fe deficiency considerably decreased the amount of LHCII trimer, ATPase-F1 portion, cyt b6/f and RuBisCO. No or less reduction, was observed for PSI(RCI+LHCI), the PSII-core monomer, and the PSII subcomplex, while an increase in the LHCII monomer was noted. Under iron deficiency, Cd proved to be very deleterious to MPCs, except for the PSII subcomplex, the LHCII monomer and free proteins which were increased. Iron proved to be very protective in retaining almost all the complexes. MPCs showed greater susceptibility to Cd than Fe deficiency, mainly at the level of RuBisCO and cyt b6/f; an increase in the amount of the PSII subcomplex, LHCII monomer and free proteins indicates differences in the mechanisms affected by Fe deficiency and Cd stress when compared to Fe-fed plants. This study furthers our understanding of the sites actually damaged in MPCs under Fe deficiency and Cd stress. A role emerges for iron in the protection of MPCs and, hence, of the chloroplast. The present study also indicates the importance of iron for efficient phytoextraction/phytoremediation.
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Affiliation(s)
- M Irfan Qureshi
- Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India
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808
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Scully CC, Rutledge PJ. Synthesis and electrochemical studies of disubstituted ferrocene/dipeptide conjugates with sulfur-containing side chains. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.05.070] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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809
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Borovicka J, Kotrba P, Gryndler M, Mihaljevic M, Randa Z, Rohovec J, Cajthaml T, Stijve T, Dunn CE. Bioaccumulation of silver in ectomycorrhizal and saprobic macrofungi from pristine and polluted areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:2733-44. [PMID: 20303145 DOI: 10.1016/j.scitotenv.2010.02.031] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 02/16/2010] [Accepted: 02/17/2010] [Indexed: 05/22/2023]
Abstract
Macrofungi are effective accumulators of Ag. This study provides a comprehensive review of this phenomenon supported by original data on the Ag concentrations of macrofungi from pristine and Ag-polluted areas. In pristine areas, the median Ag concentrations of ectomycorrhizal (ECM) and saprobic (SAP) macrofungi were 0.79 and 2.94 mg kg(-1), respectively. In these areas, hyperaccumulation thresholds for Ag in ECM and SAP macrofungi are proposed as 100 and 300 mg kg(-1), respectively. In a Ag-polluted area, the Ag concentrations in macrofungi (ECM and SAP) were significantly elevated with the median value of 24.7 mg kg(-1) and the highest concentrations in Amanita spp. of the section Vaginatae (304-692 mg kg(-1)). The intracellular speciation of Ag in fruit-bodies of the Ag-accumulator Amanita submembranacea was inspected by size exclusion chromatography followed by sulfhydryl-specific fluorimetric assays of ligands using reverse phase high-performance liquid chromatography and improved polyacrylamide gel electrophoresis. Virtually all Ag was found to be intracellular and sequestered in the major 7 kDa and minor 3.3 kDa complexes. The lack of glutathione and phytochelatins and the presence of a single 3 kDa sulfhydryl-containing peptide in the isolated Ag-complexes suggest that detoxification of Ag in A. submembranacea may rely on metallothionein. Vertical distribution of Ag in a polluted forest soil profile has shown substantial enrichment in organic horizons; in polluted technosol, the highest Ag concentrations were found in surface layers. Standardized EDTA extraction of Ag in both the investigated soil profiles showed relatively low Ag extractibility, generally within the range of 2.2-7.7% of total Ag content.
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Affiliation(s)
- Jan Borovicka
- Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez near Prague, Czech Republic.
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810
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Ritter A, Ubertini M, Romac S, Gaillard F, Delage L, Mann A, Cock JM, Tonon T, Correa JA, Potin P. Copper stress proteomics highlights local adaptation of two strains of the model brown alga Ectocarpus siliculosus. Proteomics 2010; 10:2074-88. [PMID: 20373519 DOI: 10.1002/pmic.200900004] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2009] [Accepted: 11/19/2009] [Indexed: 11/10/2022]
Abstract
Ectocarpus siliculosus is a cosmopolitan brown alga with capacity to thrive in copper enriched environments. Analysis of copper toxicity was conducted in two strains of E. siliculosus isolated from (i) an uncontaminated coast in southern Peru (Es32) and (ii) a copper polluted rocky beach in northern Chile (Es524). Es32 was more sensitive than Es524, with toxicity detected at 50 microg/L Cu, whereas Es524 displayed negative effects only when exposed to 250 microg/L Cu. Differential soluble proteome profiling for each strain exposed to sub-lethal copper levels allowed to identify the induction of proteins related to processes such as energy production, glutathione metabolism as well as accumulation of HSPs. In addition, the inter-strain comparison of stress-related proteomes led to identify features related to copper tolerance in Es524, such as striking expression of a PSII Mn-stabilizing protein and a Fucoxanthine chlorophyll a-c binding protein. Es524 also expressed specific stress-related enzymes such as RNA helicases from the DEAD box families and a vanadium-dependent bromoperoxidase. These observations were supported by RT-qPCR for some of the identified genes and an enzyme activity assay for vanadium-dependent bromoperoxidase. Therefore, the occurrence of two different phenotypes within two distinct E. siliculosus strains studied at the physiological and proteomic levels strongly suggest that persistent copper stress may represent a selective force leading to the development of strains genetically adapted to copper contaminated sites.
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Affiliation(s)
- Andrés Ritter
- Université Pierre et Marie Curie-Paris 6, Végétaux Marins et Biomolécules, Station Biologique, Place Georges Teissier, Roscoff, France
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811
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Conn S, Gilliham M. Comparative physiology of elemental distributions in plants. ANNALS OF BOTANY 2010; 105:1081-102. [PMID: 20410048 PMCID: PMC2887064 DOI: 10.1093/aob/mcq027] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 11/16/2009] [Accepted: 12/16/2009] [Indexed: 05/18/2023]
Abstract
BACKGROUND Plants contain relatively few cell types, each contributing a specialized role in shaping plant function. With respect to plant nutrition, different cell types accumulate certain elements in varying amounts within their storage vacuole. The role and mechanisms underlying cell-specific distribution of elements in plants is poorly understood. SCOPE The phenomenon of cell-specific elemental accumulation has been briefly reviewed previously, but recent technological advances with the potential to probe mechanisms underlying elemental compartmentation have warranted an updated evaluation. We have taken this opportunity to catalogue many of the studies, and techniques used for, recording cell-specific compartmentation of particular elements. More importantly, we use three case-study elements (Ca, Cd and Na) to highlight the basis of such phenomena in terms of their physiological implications and underpinning mechanisms; we also link such distributions to the expression of known ion or solute transporters. CONCLUSIONS Element accumulation patterns are clearly defined by expression of key ion or solute transporters. Although the location of element accumulation is fairly robust, alterations in expression of certain solute transporters, through genetic modifications or by growth under stress, result in perturbations to these patterns. However, redundancy or induced pleiotropic expression effects may complicate attempts to characterize the pathways that lead to cell-specific elemental distribution. Accumulation of one element often has consequences on the accumulation of others, which seems to be driven largely to maintain vacuolar and cytoplasmic osmolarity and charge balance, and also serves as a detoxification mechanism. Altered cell-specific transcriptomics can be shown, in part, to explain some of this compensation.
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Affiliation(s)
- Simon Conn
- School of Agriculture, Food, and Wine, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia
| | - Matthew Gilliham
- School of Agriculture, Food, and Wine, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia
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812
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Gupta DK, Huang HG, Yang XE, Razafindrabe BHN, Inouhe M. The detoxification of lead in Sedum alfredii H. is not related to phytochelatins but the glutathione. JOURNAL OF HAZARDOUS MATERIALS 2010; 177:437-44. [PMID: 20047791 DOI: 10.1016/j.jhazmat.2009.12.052] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 12/09/2009] [Accepted: 12/09/2009] [Indexed: 05/20/2023]
Abstract
Two ecotypes of S. alfredii [Pb accumulating (AE) and Pb non-accumulating (NAE)] differing in their ability in accumulating Pb were exposed to different Pb levels to evaluate the effects on plant length, photosynthetic pigments, antioxidant enzymes (SOD and APX), cysteine, non-protein thiols (NP-SH), phytochelatins (PCs) and glutathione (GSH) vis-à-vis Pb accumulation. Both ecotypes showed significant Pb accumulation in roots, however only the AE showed significant Pb accumulation in shoots. We found that both AE and NAE of S. alfredii-induced biosynthesis of GSH rather than phytochelatins in their tissue upon addition of even high Pb levels (200 microM). Root and shoot length were mostly affected in both ecotypes after addition of higher Pb concentrations and on longer durations, however photosynthetic pigments did not alter upon addition of any Pb treatment. Both superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities of AE were higher than NAE. The levels of cysteine and NP-SH were also higher in AE than in NAE. Hence, the characteristic Pb accumulation of ecotypes differed presumably in relation to their capacity for detoxification of Pb. These results suggest that enzymatic and non-enzymatic antioxidants play a key role in the detoxification of Pb-induced toxic effects in Sedum alfredii. This plant can be used as an indicator species for Pb contamination.
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Affiliation(s)
- D K Gupta
- Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, Zhejiang University, Hua-jian-chi Campus, Hangzhou 310029, China.
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813
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Durand TC, Sergeant K, Planchon S, Carpin S, Label P, Morabito D, Hausman JF, Renaut J. Acute metal stress in Populus tremula x P. alba (717-1B4 genotype): leaf and cambial proteome changes induced by cadmium 2+. Proteomics 2010; 10:349-68. [PMID: 20148406 DOI: 10.1002/pmic.200900484] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The comprehension of metal homeostasis in plants requires the identification of molecular markers linked to stress tolerance. Proteomic changes in leaves and cambial zone of Populus tremula x P. alba (717-1B4 genotype) were analyzed after 61 days of exposure to cadmium (Cd) 360 mg/kg soil dry weight in pot-soil cultures. The treatment led to an acute Cd stress with a reduction of growth and photosynthesis. Cd stress induced changes in the display of 120 spots for leaf tissue and 153 spots for the cambial zone. It involved a reduced photosynthesis, resulting in a profound reorganisation of carbon and carbohydrate metabolisms in both tissues. Cambial cells underwent stress from the Cd actually present inside the tissue but also a deprivation of photosynthates caused by leaf stress. An important tissue specificity of the response was observed, according to the differences in cell structures and functions.
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Affiliation(s)
- Thomas C Durand
- CRP-Gabriel Lippmann, Department Environment and Agro-biotechnologies, Belvaux, GD, Luxembourg
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814
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Hradilová J, Rehulka P, Rehulková H, Vrbová M, Griga M, Brzobohatý B. Comparative analysis of proteomic changes in contrasting flax cultivars upon cadmium exposure. Electrophoresis 2010; 31:421-31. [PMID: 20084635 DOI: 10.1002/elps.200900477] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cadmium (Cd) is classified as a serious pollutant due to its high toxicity, high carcinogenicity, and widespread presence in the environment. Phytoremediation represents an effective low-cost approach for removing pollutants from contaminated soils, and a crop with significant phytoremediation potential is flax. However, significant differences in Cd accumulation and tolerance were previously found among commercial flax cultivars. Notably, cv. Jitka showed substantially higher tolerance to elevated Cd levels in soil and plant tissues than cv. Tábor. Here, significant changes in the expression of 14 proteins (related to disease/defense, metabolism, protein destination and storage, signal transduction, energy and cell structure) were detected by image and mass spectrometric analysis of two-dimensionally separated proteins extracted from Cd-treated cell suspension cultures derived from these contrasting cultivars. Further, two proteins, ferritin and glutamine synthetase (a key enzyme in glutathione biosynthesis), were only up-regulated by Cd in cv. Jitka, indicating that Cd tolerance mechanisms in this cultivar may include maintenance of low Cd levels at sensitive sites by ferritin and low-molecular weight thiol peptides binding Cd. The identified changes could facilitate marker-assisted breeding for Cd tolerance and the development of transgenic flax lines with enhanced Cd tolerance and accumulation capacities for phytoremediating Cd-contaminated soils.
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Affiliation(s)
- Jana Hradilová
- Department of Molecular Biology and Radiobiology, Mendel University of Agriculture and Forestry in Brno, Zemedelská, Brno, Czech Republic
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815
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Harada E, Hokura A, Takada S, Baba K, Terada Y, Nakai I, Yazaki K. Characterization of Cadmium Accumulation in Willow as a Woody Metal Accumulator Using Synchrotron Radiation-Based X-Ray Microanalyses. ACTA ACUST UNITED AC 2010; 51:848-53. [DOI: 10.1093/pcp/pcq039] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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816
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Tezuka K, Miyadate H, Katou K, Kodama I, Matsumoto S, Kawamoto T, Masaki S, Satoh H, Yamaguchi M, Sakurai K, Takahashi H, Satoh-Nagasawa N, Watanabe A, Fujimura T, Akagi H. A single recessive gene controls cadmium translocation in the cadmium hyperaccumulating rice cultivar Cho-Ko-Koku. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2010; 120:1175-82. [PMID: 20039013 DOI: 10.1007/s00122-009-1244-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Accepted: 12/08/2009] [Indexed: 05/21/2023]
Abstract
The heavy metal cadmium (Cd) is highly toxic to humans and can enter food chains from contaminated crop fields. Understanding the molecular mechanisms of Cd accumulation in crop species will aid production of safe Cd-free food. Here, we identified a single recessive gene that allowed higher Cd translocation in rice, and also determined the chromosomal location of the gene. The Cd hyperaccumulator rice variety Cho-Ko-Koku showed 3.5-fold greater Cd translocation than the no-accumulating variety Akita 63 under hydroponics. Analysis of an F(2) population derived from these cultivars gave a 1:3 segregation ratio for high:low Cd translocation. This indicates that a single recessive gene controls the high Cd translocation phenotype. A QTL analysis identified a single QTL, qCdT7, located on chromosome 7. On a Cd-contaminated field, Cd accumulation in the F(2) population showed continuous variation with considerable transgression. Three QTLs for Cd accumulation were identified and the peak of the most effective QTL mapped to the same region as qCdT7. Our data indicate that Cd translocation mediated by the gene on qCdT7 plays an important role in Cd accumulation on contaminated soil.
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Affiliation(s)
- Kouichi Tezuka
- Laboratory of Plant Genetics and Breeding, Department of Biological Production, Faculty of Bioresource Sciences, Akita Prefectural University, Kaidoubata-Nishi 241-438, Shimoshinjyo-Nakano, Akita, 010-0195, Japan
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817
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Jiang W, Liu D. Pb-induced cellular defense system in the root meristematic cells of Allium sativum L. BMC PLANT BIOLOGY 2010; 10:40. [PMID: 20196842 PMCID: PMC2848760 DOI: 10.1186/1471-2229-10-40] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Accepted: 03/02/2010] [Indexed: 05/03/2023]
Abstract
BACKGROUND Electron microscopy (EM) techniques enable identification of the main accumulations of lead (Pb) in cells and cellular organelles and observations of changes in cell ultrastructure. Although there is extensive literature relating to studies on the influence of heavy metals on plants, Pb tolerance strategies of plants have not yet been fully explained. Allium sativum L. is a potential plant for absorption and accumulation of heavy metals. In previous investigations the effects of different concentrations (10(-5) to 10(-3) M) of Pb were investigated in A. sativum, indicating a significant inhibitory effect on shoot and root growth at 10(-3) to 10(-4) M Pb. In the present study, we used EM and cytochemistry to investigate ultrastructural alterations, identify the synthesis and distribution of cysteine-rich proteins induced by Pb and explain the possible mechanisms of the Pb-induced cellular defense system in A. sativum. RESULTS After 1 h of Pb treatment, dictyosomes were accompanied by numerous vesicles within cytoplasm. The endoplasm reticulum (ER) with swollen cisternae was arranged along the cell wall after 2 h. Some flattened cisternae were broken up into small closed vesicles and the nuclear envelope was generally more dilated after 4 h. During 24-36 h, phenomena appeared such as high vacuolization of cytoplasm and electron-dense granules in cell walls, vacuoles, cytoplasm and mitochondrial membranes. Other changes included mitochondrial swelling and loss of cristae, and vacuolization of ER and dictyosomes during 48-72 h. In the Pb-treatment groups, silver grains were observed in cell walls and in cytoplasm, suggesting the Gomori-Swift reaction can indirectly evaluate the Pb effects on plant cells. CONCLUSIONS Cell walls can immobilize some Pb ions. Cysteine-rich proteins in cell walls were confirmed by the Gomori-Swift reaction. The morphological alterations in plasma membrane, dictyosomes and ER reflect the features of detoxification and tolerance under Pb stress. Vacuoles are ultimately one of main storage sites of Pb. Root meristematic cells of A. sativum exposed to lower Pb have a rapid and effective defense system, but with the increased level of Pb in the cytosol, cells were seriously injured.
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Affiliation(s)
- Wusheng Jiang
- Library of Tianjin Normal University, Tianjin 300387, PR China
| | - Donghua Liu
- Department of Biology, Tianjin Normal University, Tianjin 300387, PR China
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818
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Vamerali T, Bandiera M, Mosca G. Field crops for phytoremediation of metal-contaminated land. A review. ENVIRONMENTAL CHEMISTRY LETTERS 2010; 8:1-17. [PMID: 0 DOI: 10.1007/s10311-009-0268-0] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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819
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Pietrini F, Zacchini M, Iori V, Pietrosanti L, Ferretti M, Massacci A. Spatial distribution of cadmium in leaves and its impact on photosynthesis: examples of different strategies in willow and poplar clones. PLANT BIOLOGY (STUTTGART, GERMANY) 2010; 12:355-363. [PMID: 20398241 DOI: 10.1111/j.1438-8677.2009.00258.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The interaction of cadmium (Cd) with photosynthesis was investigated in poplar (Populus x canadensis Mönch., clone A4A, Populus nigra L., clone Poli) and willow (Salix alba L., clone SS5) clones that had different leaf metal concentrations in preliminary experiments. Plants grown in the presence of 50 microm CdSO(4) for 3 weeks under hydroponic conditions were used to examine leaf gas exchange, chlorophyll fluorescence parameters and images, and for Cd detection using energy dispersive X-ray fluorescence (ED-XRF). Leaves were finally analysed for Cd and phytochelatin concentrations. Results showed that SS5 had the highest leaf Cd concentration and high gas exchange activity similar to that of Poli, which had the lowest Cd concentration. Leaf fluorescence images evidenced in large undamaged areas of SS5 corresponded to high values of F(v)/F(m), F(o), PhiPSII, qP and NPQ, while patches of dark colour (visible necrosis) close to the main vein corresponded to low values of these parameters. In A4A, these necrotic patches were more diffuse on the leaf blade and associated with a range of fluorescence parameter values. ED-XRF analysis indicated that Cd was only detectable in necroses of SS5 leaves, while in A4A it was relatively more diffuse. Phytochelatins (PCs) were not detected in SS5, while their concentration was high in both Poli and A4A. The absence of these molecules in SS5 is thought to favour confinement of high accumulations of Cd to necrotic areas and gives SS5 the ability to maintain high photosynthesis and transpiration in remaining parts of the leaf.
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Affiliation(s)
- F Pietrini
- Institute of Agro-Environment and Forest Biology of the National Research Council, Monterotondo Scalo (Roma), Italy
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820
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Moody C, Green ID. Assimilation of Cd and Cu by the carnivorous plant Sarracenia leucophylla raf. fed contaminated prey. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:1610-1616. [PMID: 20141102 DOI: 10.1021/es9019386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Many species of carnivorous plants have become endangered through exposure to multiple risks such as habitat loss, illegal poaching, and pollution. A potential threat to these plants posed by pollution stems from the contamination of their invertebrate prey with trace metals. This study examined the potential for prey to act as sources of the trace metals Cd and Cu for the pitcher plant Sarracenia leucophylla. Cd- and Cu-contaminated Diptera larvae were fed to S. leucophylla plants in separate experiments. The results demonstrated that Cd and Cu were readily transferred to the shoots of S. leucophylla in a dose-dependent manner. While the assimilation of Cu decreased with treatment level, the assimilation of Cd did not. Some assimilated Cu appeared to be translocated to the roots, but Cd was strongly retained in the shoots, where it was related to a reduction in shoot biomass. This suggested that on exposure to Cd-contaminated prey, the plants either experienced phytotoxicity or there was disruption of nutrient acquisition from the prey. Accumulation of Cu was not related to any sign of phytotoxicity.
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Affiliation(s)
- Christopher Moody
- The School of Conservation Sciences, Bournemouth University, Talbot Campus, Poole, Dorset, BH12 5BB, United Kingdom
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821
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Lee K, Bae DW, Kim SH, Han HJ, Liu X, Park HC, Lim CO, Lee SY, Chung WS. Comparative proteomic analysis of the short-term responses of rice roots and leaves to cadmium. JOURNAL OF PLANT PHYSIOLOGY 2010; 167:161-8. [PMID: 19853963 DOI: 10.1016/j.jplph.2009.09.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 09/22/2009] [Accepted: 09/22/2009] [Indexed: 05/18/2023]
Abstract
Cadmium (Cd) is a non-essential heavy metal that is recognized as a major environmental pollutant. While Cd responses and toxicities in some plant species have been well established, there are few reports about the effects of short-term exposure to Cd on rice, a model monocotyledonous plant, at the proteome level. To investigate the effect of Cd in rice, we monitored the influence of Cd exposure on root and leaf proteomes. After Cd treatment, root and leaf tissues were separately collected and leaf proteins were fractionated with polyethylene glycol. Differentially regulated proteins were selected after image analysis and identified using MALDI-TOF MS. A total of 36 proteins were up- or down-regulated following Cd treatment. As expected, total glutathione levels were significantly decreased in Cd-treated roots, and approximately half of the up-regulated proteins in roots were involved in responses to oxidative stress. These results suggested that prompt antioxidative responses might be necessary for the reduction of Cd-induced oxidative stress in roots but not in leaves. In addition, RNA gel blot analysis showed that the proteins identified in the proteomic analysis were also differentially regulated at the transcriptional level. Collectively, our study provides insights into the integrated molecular mechanisms of early responses to Cd in rice.
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Affiliation(s)
- Kyunghee Lee
- Division of Applied Life Science (BK21 Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, Republic of Korea
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822
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823
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Kafel A, Nadgórska-Socha A, Gospodarek J, Babczyńska A, Skowronek M, Kandziora M, Rozpedek K. The effects of Aphis fabae infestation on the antioxidant response and heavy metal content in field grown Philadelphus coronarius plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:1111-9. [PMID: 19945149 DOI: 10.1016/j.scitotenv.2009.11.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 11/05/2009] [Accepted: 11/06/2009] [Indexed: 05/10/2023]
Abstract
The purpose of this study was to explore a possible relationship between the soil availability of metals and their concentrations in various parts of Philadelphuscoronarius plants. Moreover, the possible impact of an aphid infestation on the contamination and antioxidant response of plants from the urban environment of Kraków and the reference rural area of Zagaje Stradowskie (southern Poland) was analyzed. The contents of the glutathione, proline, non-protein -SH groups, antioxidants, and phosphorous and the levels of guaiacol peroxidase and catalase activity in leaves and shoots either infested or not by the aphid Aphis fabae Scop., were measured. The potential bioavailability of metals (Cd; Cu; Ni; Pb; Zn) in the soil and their concentrations in P. coronarius plants originating from both sites were compared. The antioxidant responses were generally elevated in the plants in the polluted area. Such reactions were additionally changed by aphid infestation. Generally, the concentrations of metals in the HNO(3) and CaCl(2) extractants of the soils from two layers at the 0-20 and 20-40 cm depths from the polluted area were higher than in those from the reference area. Such differences were found for nickel and lead (in all examined extractants), zinc (in soil extractants from the layer at 20-40 cm) and cadmium (in HNO(3) extractants). Significant positive relationships between the lead concentrations in the soil and in the plants were found. In the parts of plants from the polluted area, higher concentrations of Pb and Zn (leaves and shoots) and Cd (shoots) were recorded. The shoots and leaves of plants infested with aphids had higher concentrations of Zn but lower Pb. Moreover, their leaves had higher contaminations of Cu and Ni. In conclusion, aphids affected not only the antioxidant response of the plants but also their contamination with metals, especially contamination of the leaves.
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Affiliation(s)
- Alina Kafel
- Department of Animal Physiology and Ecotoxicology, University of Silesia, Bankowa 9, PL 40-007 Katowice, Poland.
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824
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Yang B, Zhou M, Shu WS, Lan CY, Ye ZH, Qiu RL, Jie YC, Cui GX, Wong MH. Constitutional tolerance to heavy metals of a fiber crop, ramie (Boehmeria nivea), and its potential usage. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2010; 158:551-8. [PMID: 19828218 DOI: 10.1016/j.envpol.2009.08.043] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 08/11/2009] [Accepted: 08/17/2009] [Indexed: 05/20/2023]
Abstract
It is observed that ramie (Boehmeria nivea), an economic fiber crop, can establish and colonize metal-contaminated sites in China. Metal tolerance and accumulation by ramie originating from 13 metal-contaminated and 4 "clean" sites in China were compared under field and hydroponic conditions. All selected populations and germplasms displayed good growth performance under diverse metal-contaminated habitats; while growth responses, metal accumulation and tolerance were similar among the 8 populations and 2 germplasms when exposed to solutions containing elevated As, Cd, Pb, or Zn in the laboratory. These revealed that ramie possesses a certain degree of constitutional metal tolerance. To our knowledge, this is the first report of constitutional metal tolerance possessed by a fiber crop. Ramie can be considered as a good candidate for both fiber production and phytoremediation of sites contaminated by multi-metals, as it accumulates relative low metal concentrations, but possesses both high biomass and high economic value.
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Affiliation(s)
- B Yang
- State Key Laboratory of Biocontrol, and School of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, PR China
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825
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Kopittke PM, Blamey FPC, Asher CJ, Menzies NW. Trace metal phytotoxicity in solution culture: a review. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:945-54. [PMID: 20054033 DOI: 10.1093/jxb/erp385] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Solution culture has been used extensively to determine the phytotoxic effects of trace metals. A review of the literature from 1975 to 2009 was carried out to evaluate the effects of As(V), Cd(II), Co(II), Cu(II), Hg(II), Mn(II), Ni(II), Pb(II), and Zn(II) on plants grown in solution. A total of 119 studies was selected using criteria that allowed a valid comparison of the results; reported toxic concentrations varied by five orders of magnitude. Across a range of plant species and experimental conditions, the phytotoxicity of the trace metals followed the trend (from most to least toxic): Pb approximately Hg >Cu >Cd approximately As >Co approximately Ni approximately Zn >Mn, with median toxic concentrations of (muM): 0.30 Pb, 0.47 Hg, 2.0 Cu, 5.0 Cd, 9.0 As, 17 Co, 19 Ni, 25 Zn, and 46 Mn. For phytotoxicity studies in solution culture, we suggest (i) plants should be grown in a dilute solution which mimics the soil solution, or that, at a minimum, contains Ca and B, (ii) solution pH should be monitored and reported (as should the concentrations of the trace metal of interest), (iii) assessment should be made of the influence of pH on solution composition and ion speciation, and (iv) both the period of exposure to the trace metal and the plant variable measured should be appropriate. Observing these criteria will potentially lead to reliable data on the relationship between growth depression and the concentration of the toxic metal in solution.
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Affiliation(s)
- Peter M Kopittke
- The University of Queensland, School of Land, Crop and Food Sciences, St Lucia, Queensland, Australia, 4072.
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826
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Satarug S, Garrett SH, Sens MA, Sens DA. Cadmium, environmental exposure, and health outcomes. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:182-90. [PMID: 20123617 PMCID: PMC2831915 DOI: 10.1289/ehp.0901234] [Citation(s) in RCA: 703] [Impact Index Per Article: 50.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Accepted: 10/05/2009] [Indexed: 05/06/2023]
Abstract
OBJECTIVES We provide an update of the issues surrounding health risk assessment of exposure to cadmium in food. DATA SOURCES We reviewed epidemiologic studies published between 2004 and 2009 concerning the bioavailability of cadmium in food, assessment of exposure, and body burden estimate, along with exposure-related effects in nonoccupationally exposed populations. DATA EXTRACTION AND SYNTHESIS Bioavailability of ingested cadmium has been confirmed in studies of persons with elevated dietary exposure, and the findings have been strengthened by the substantial amounts of cadmium accumulated in kidneys, eyes, and other tissues and organs of environmentally exposed individuals. We hypothesized that such accumulation results from the efficient absorption and systemic transport of cadmium, employing multiple transporters that are used for the body's acquisition of calcium, iron, zinc, and manganese. Adverse effects of cadmium on kidney and bone have been observed in environmentally exposed populations at frequencies higher than those predicted from models of exposure. Increasing evidence implicates cadmium in the risk of diseases that involve other tissues and organ systems at cadmium concentrations that do not produce effects on bone or renal function. CONCLUSIONS Population data raise concerns about the validity of the current safe intake level that uses the kidney as the sole target in assessing the health risk from ingested cadmium. The data also question the validity of incorporating the default 5% absorption rate in the threshold-type risk assessment model, known as the provisional tolerable weekly intake (PTWI), to derive a safe intake level for cadmium.
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Affiliation(s)
- Soisungwan Satarug
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58202, USA.
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827
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Tuomainen M, Tervahauta A, Hassinen V, Schat H, Koistinen KM, Lehesranta S, Rantalainen K, Häyrinen J, Auriola S, Anttonen M, Kärenlampi S. Proteomics of Thlaspi caerulescens accessions and an inter-accession cross segregating for zinc accumulation. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:1075-87. [PMID: 20048332 PMCID: PMC2826651 DOI: 10.1093/jxb/erp372] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 11/25/2009] [Accepted: 11/30/2009] [Indexed: 05/04/2023]
Abstract
Metal hyperaccumulator plants have previously been characterized by transcriptomics, but reports on other profiling techniques are scarce. Protein profiles of Thlaspi caerulescens accessions La Calamine (LC) and Lellingen (LE) and lines derived from an LCxLE cross were examined here to determine the co-segregation of protein expression with the level of zinc (Zn) hyperaccumulation. Although hydrophobic proteins such as membrane transporters are not disclosed, this approach has the potential to reveal other proteins important for the Zn hyperaccumulation trait. Plants were exposed to metals. Proteins were separated using two-dimensional electrophoresis and those showing differences among accessions, lines or metal exposures were subjected to mass-spectrometric analysis for identification. Crossing decreased the number of different proteins in the lines compared with the parents, more so in the shoots than in the roots, but the frequencies of Zn-responsive proteins were about the same in the accessions and the selection lines. This supports the finding that the Zn accumulation traits are mainly determined by the root and that Zn accumulation itself is not the reason for the co-segregation. This study demonstrates that crossing accessions with contrasting Zn accumulation traits is a potent tool to investigate the mechanisms behind metal hyperaccumulation. Four tentatively identified root proteins showed co-segregation with high or low Zn accumulation: manganese superoxide dismutase, glutathione S-transferase, S-formyl glutathione hydrolase, and translation elongation factor 5A-2. However, these proteins may not be the direct determinants of Zn accumulation. The role of these and other tentatively identified proteins in Zn accumulation and tolerance is discussed.
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Affiliation(s)
- Marjo Tuomainen
- Department of Biosciences, University of Kuopio, PO Box 1627, FI-70211 Kuopio, Finland.
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828
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Trampczynska A, Küpper H, Meyer-Klaucke W, Schmidt H, Clemens S. Nicotianamine forms complexes with Zn(ii)in vivo. Metallomics 2010; 2:57-66. [DOI: 10.1039/b913299f] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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829
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Sárvári E, Gáspár L, Solti A, Mészáros I, Záray G, Fodor F. Cd-Fe interactions: comparison of the effects of iron deficiency and cadmium on growth and photosynthetic performance in poplar. ACTA BIOLOGICA HUNGARICA 2010; 61 Suppl:136-48. [PMID: 21565772 DOI: 10.1556/abiol.61.2010.suppl.14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To check the importance of Cd-induced iron deficiency in Cd stress, symptoms of Cd stress were compared with those of iron deficiency or the combination of these two stresses. Poplar plants grown in hydroponics with Fe-EDTA (e) or Fe-citrate (c) up to four-leaf stage were treated for two weeks either by the withdrawal of iron (Fedef), or supplying 10 μM Cd(NO3)2 in the presence (Cad) or absence of an iron source (Fedef + Cad). Cadmium and iron content of leaves developing under the stress was in the order of cCad > eCad > cFedef + Cad and cCad ≈ eFedef ≈ cFedef + Cad < eCad < cFedef, respectively. Growth inhibition was much stronger in Cad than Fedef plants. The inhibitory effects on CO2 fixation, maximal and actual efficiency of PSII, chlorophyll synthesis, as well as the stimulation of the accumulation of violaxanthin cycle components and increase in non-photochemical quenching were the strongest in cFedef+Cad plants, otherwise these parameters changed parallel to the iron deficiency of leaves. Tendency of changes in thylakoid composition were similar under Cad treatments and strong iron deficiency: particularly PSI and LHCII decreased. Therefore, the development of the photosynthetic apparatus under Cd stress was mainly influenced by the Cd-induced strong iron deficiency, while leaf growth was affected primarily by the presence of Cd.
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Affiliation(s)
- Eva Sárvári
- Department of Plant Physiology and Molecular Plant Biology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary.
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830
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Appenroth KJ. Definition of “Heavy Metals” and Their Role in Biological Systems. SOIL BIOLOGY 2010. [DOI: 10.1007/978-3-642-02436-8_2] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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831
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Tamás L, Mistrík I, Huttová J, Halusková L, Valentovicová K, Zelinová V. Role of reactive oxygen species-generating enzymes and hydrogen peroxide during cadmium, mercury and osmotic stresses in barley root tip. PLANTA 2010; 231:221-31. [PMID: 19898864 DOI: 10.1007/s00425-009-1042-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Accepted: 10/18/2009] [Indexed: 05/08/2023]
Abstract
The effect of cadmium (Cd) on the expression and activity of NADPH oxidase, peroxidase and oxalate oxidase as well as on the expression of aquaporins and dehydrins was studied in barley root tip. The root tip represented intact apical part of the barley root containing the root cap, meristems and elongation zone. Except stress induced by Cd, barley root tips were analysed after their exposure to phytotoxic concentration of mercury (Hg)-, hydrogen peroxide (H2O2)- or polyethylene glycol (PEG)-induced water stress in order to compare the Cd-induced changes with changes induced by these other stress factors. Cd, Hg, H2O2 and with some exceptions also PEG treatments caused similar alterations in the gene expression of reactive oxygen species (ROS)-generating and water deficiency-related genes, and in the activity of ROS-generating enzymes. These evidences support our opinion that ROS accumulation and water imbalance are the common symptoms of these stress factors and that the elevated production of H2O2 plays, probably as a signal molecule, a key role in the induction of plant responses to abiotic stresses in barley root tip. On the other hand, H2O2 at permanent high concentration is probably the main toxic factor during stress conditions.
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Affiliation(s)
- Ladislav Tamás
- Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 14, 84523 Bratislava, Slovak Republic.
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832
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Basa B, Solti Á, Sárvári É, Tamás L. Housekeeping gene selection in poplar plants under Cd-stress: comparative study for real-time PCR normalisation. FUNCTIONAL PLANT BIOLOGY : FPB 2010; 36:1079-1087. [PMID: 32688719 DOI: 10.1071/fp09073] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Accepted: 08/20/2009] [Indexed: 06/11/2023]
Abstract
Real-time RT-PCR is currently the most sensitive, specific and precise approach to analyse gene expression changes in plant stress studies. The determination of biologically meaningful transcript quantities requires accurate normalisation of the raw data. During relative quantification the reliability of the results depends on the stable expression of the endogenous control genes across the experimental samples. Four widely used internal control genes (cyclophilin, elongation factor 1α, polyubiquitin, tubulin β-chain) and two potential candidates (serine/threonine-protein phosphatase 2A and ubiquitin-conjugating enzyme) genes were assessed under Cd-stress and at different developmental stages in leaves of Populus jacquemontiana D. var. glauca H. Complementary DNA (RiboGreen) based quantification method revealed variations in the expression level of reference genes. The variability was more pronounced under severe stress conditions. Less variation was observed in the case of ef-1α, pp2a and ubc10. Transcript level changes of a target gene, psa-h, was also evaluated by two independent normalisation strategies, by the RiboGreen method or by using multiple references. The impact of variability of reference gene on the target gene evaluation was demonstrated. It was proved that in the absence of suitable housekeeping genes, for example under severe stress, RiboGreen method is convenient tool for transcript normalisation.
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Affiliation(s)
- Brigitta Basa
- Department of Plant Physiology and Molecular Plant Biology, Eötvös Loránd University, Pázmány Péter stny, 1/C, H-1117, Budapest, Hungary
| | - Ádám Solti
- Department of Plant Physiology and Molecular Plant Biology, Eötvös Loránd University, Pázmány Péter stny, 1/C, H-1117, Budapest, Hungary
| | - Éva Sárvári
- Department of Plant Physiology and Molecular Plant Biology, Eötvös Loránd University, Pázmány Péter stny, 1/C, H-1117, Budapest, Hungary
| | - László Tamás
- Department of Plant Physiology and Molecular Plant Biology, Eötvös Loránd University, Pázmány Péter stny, 1/C, H-1117, Budapest, Hungary
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833
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Farinati S, DalCorso G, Bona E, Corbella M, Lampis S, Cecconi D, Polati R, Berta G, Vallini G, Furini A. Proteomic analysis of Arabidopsis halleri shoots in response to the heavy metals cadmium and zinc and rhizosphere microorganisms. Proteomics 2009; 9:4837-50. [PMID: 19810031 DOI: 10.1002/pmic.200900036] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Arabidopsis halleri has the rare ability to colonize heavy metal-polluted sites and is an emerging model for research on adaptation and metal hyperaccumulation. The aim of this study was to analyze the effect of plant-microbe interaction on the accumulation of cadmium (Cd) and zinc (Zn) in shoots of an ecotype of A. halleri grown in heavy metal-contaminated soil and to compare the shoot proteome of plants grown solely in the presence of Cd and Zn or in the presence of these two metals and the autochthonous soil rhizosphere-derived microorganisms. The results of this analysis emphasized the role of plant-microbe interaction in shoot metal accumulation. Differences in protein expression pattern, identified by a proteomic approach involving 2-DE and MS, indicated a general upregulation of photosynthesis-related proteins in plants exposed to metals and to metals plus microorganisms, suggesting that metal accumulation in shoots is an energy-demanding process. The analysis also showed that proteins involved in plant defense mechanisms were downregulated indicating that heavy metals accumulation in leaves supplies a protection system and highlights a cross-talk between heavy metal signaling and defense signaling.
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Affiliation(s)
- Silvia Farinati
- Department of Biotechnology, University of Verona, Verona, Italy
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834
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Ghasemi R, Ghaderian SM, Krämer U. Interference of nickel with copper and iron homeostasis contributes to metal toxicity symptoms in the nickel hyperaccumulator plant Alyssum inflatum. THE NEW PHYTOLOGIST 2009; 184:566-580. [PMID: 19691676 DOI: 10.1111/j.1469-8137.2009.02993.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The divalent cations of several transition metal elements have similar chemical properties and, when present in excess, one metal can interfere with the homeostasis of another. To better understand the role of interactions between transition metals in the development of metal toxicity symptoms in plants, the effects of exposure to excess nickel (Ni) on copper (Cu) and iron (Fe) homeostasis in the Ni hyperaccumulator plant Alyssum inflatum were examined. Alyssum inflatum was hypertolerant to Ni, but not to Cu. Exposure to elevated subtoxic Ni concentrations increased Cu sensitivity, associated with enhanced Cu accumulation and enhanced root surface Cu(II)-specific reductase activity. Exposure to elevated Ni concentrations resulted in an inhibition of root-to-shoot translocation of Fe and concentration-dependent progressive Fe accumulation in root pericycle, endodermis and cortex cells of the differentiation zone. Shoot Fe concentrations, chlorophyll concentrations and Fe-dependent antioxidant enzyme activities were decreased in Ni-exposed plants when compared with unexposed controls. Foliar Fe spraying or increased Fe supply to roots ameliorated the chlorosis observed under exposure to high Ni concentrations. These results suggest that Ni interferes with Cu regulation and that the disruption of root-to-shoot Fe translocation is a major cause of nickel toxicity symptoms in A. inflatum.
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Affiliation(s)
- Rasoul Ghasemi
- Department of Biology, University of Isfahan, Isfahan, Iran
- Heidelberg Institute for Plant Science and BioQuant Centre, INF 267-BQ 23, University of Heidelberg, D-69120 Heidelberg, Germany
| | | | - Ute Krämer
- Heidelberg Institute for Plant Science and BioQuant Centre, INF 267-BQ 23, University of Heidelberg, D-69120 Heidelberg, Germany
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835
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Mench M, Schwitzguébel JP, Schroeder P, Bert V, Gawronski S, Gupta S. Assessment of successful experiments and limitations of phytotechnologies: contaminant uptake, detoxification and sequestration, and consequences for food safety. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2009; 16:876-900. [PMID: 19823886 DOI: 10.1007/s11356-009-0252-z] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 09/08/2009] [Indexed: 05/28/2023]
Abstract
PURPOSE The term "phytotechnologies" refers to the application of science and engineering to provide solutions involving plants, including phytoremediation options using plants and associated microbes to remediate environmental compartments contaminated by trace elements (TE) and organic xenobiotics (OX). An extended knowledge of the uptake, translocation, storage, and detoxification mechanisms in plants, of the interactions with microorganisms, and of the use of "omic" technologies (functional genomics, proteomics, and metabolomics), combined with genetic analysis and plant improvement, is essential to understand the fate of contaminants in plants and food, nonfood and technical crops. The integration of physicochemical and biological understanding allows the optimization of these properties of plants, making phytotechnologies more economically and socially attractive, decreasing the level and transfer of contaminants along the food chain and augmenting the content of essential minerals in food crops. This review will disseminate experience gained between 2004 and 2009 by three working groups of COST Action 859 on the uptake, detoxification, and sequestration of pollutants by plants and consequences for food safety. Gaps between scientific approaches and lack of understanding are examined to suggest further research and to clarify the current state-of-the-art for potential end-users of such green options. CONCLUSION AND PERSPECTIVES Phytotechnologies potentially offer efficient and environmentally friendly solutions for cleanup of contaminated soil and water, improvement of food safety, carbon sequestration, and development of renewable energy sources, all of which contribute to sustainable land use management. Information has been gained at more realistic exposure levels mainly on Cd, Zn, Ni, As, polycyclic aromatic hydrocarbons, and herbicides with less on other contaminants. A main goal is a better understanding, at the physiological, biochemical, and molecular levels, of mechanisms and their regulation related to uptake-exclusion, apoplastic barriers, xylem loading, efflux-influx of contaminants, root-to-shoot transfer, concentration and chemical speciation in xylem/phloem, storage, detoxification, and stress tolerance for plants and associated microbes exposed to contaminants (TE and OX). All remain insufficiently understood especially in the case of multiple-element and mixed-mode pollution. Research must extend from model species to plants of economic importance and include interactions between plants and microorganisms. It remains a major challenge to create, develop, and scale up phytotechnologies to market level and to successfully deploy these to ameliorate the environment and human health.
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Affiliation(s)
- Michel Mench
- UMR BIOGECO INRA 1202, Ecologie des Communautés, Université Bordeaux 1, 33405 Talence, France.
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836
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Genetically modified plants in phytoremediation of heavy metal and metalloid soil and sediment pollution. Biotechnol Adv 2009; 27:799-810. [DOI: 10.1016/j.biotechadv.2009.06.003] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 06/16/2009] [Accepted: 06/20/2009] [Indexed: 11/22/2022]
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837
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Gamalero E, Lingua G, Berta G, Glick BR. Beneficial role of plant growth promoting bacteria and arbuscular mycorrhizal fungi on plant responses to heavy metal stress. Can J Microbiol 2009; 55:501-14. [PMID: 19483778 DOI: 10.1139/w09-010] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Heavy metal pollution is a major worldwide environmental concern that has recently motivated researchers to develop a variety of novel approaches towards its cleanup. As an alternative to traditional physical and chemical methods of environmental cleanup, scientists have developed phytoremediation approaches that include the use of plants to remove or render harmless a range of compounds. Both plant growth promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) can be used to facilitate the process of phytoremediation and the growth of plants in metal-contaminated soils. This review focuses on the recent literature dealing with the effects of plant growth-promoting bacteria and AM fungi on the response of plants to heavy metal stress and points the way to strategies that may facilitate the practical realization of this technology.
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Affiliation(s)
- Elisa Gamalero
- Dipartimento di Scienze dell'Ambiente e della Vita, Università del Piemonte Orientale Amedeo Avogadro, Viale Teresa Michel 11, Alessandria, Italy.
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838
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Wojas S, Hennig J, Plaza S, Geisler M, Siemianowski O, Skłodowska A, Ruszczyńska A, Bulska E, Antosiewicz DM. Ectopic expression of Arabidopsis ABC transporter MRP7 modifies cadmium root-to-shoot transport and accumulation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2009; 157:2781-9. [PMID: 19467746 DOI: 10.1016/j.envpol.2009.04.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2008] [Revised: 04/10/2009] [Accepted: 04/20/2009] [Indexed: 05/20/2023]
Abstract
Arabidopsis MRPs/ABCCs have been shown to remove various organic and inorganic substrates from the cytosol to other subcellular compartments. Here we first demonstrate that heterologous expression of AtMRP7 in tobacco (Nicotiana tabacum var. Xanthi) modifies cadmium accumulation, distribution and tolerance. Arabidopsis MRP7 was localized both in the tonoplast and in the plasma membrane when expressed in tobacco. Its overexpression increased tobacco Cd-tolerance and resulted in enhanced cadmium concentration in leaf vacuoles, indicating more efficient detoxification by means of vacuolar storage. Heterologous AtMRP7 expression also led to more efficient retention of Cd in roots, suggesting a contribution to the control of cadmium root-to-shoot translocation. The results underscore the use of AtMRP7 in plant genetic engineering to modify the heavy-metal accumulation pattern for a broad range of applications.
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Affiliation(s)
- Sylwia Wojas
- Faculty of Biology, University of Warsaw, Miecznikowa str. 1, 02-096 Warszawa, Poland
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839
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Hugouvieux V, Dutilleul C, Jourdain A, Reynaud F, Lopez V, Bourguignon J. Arabidopsis putative selenium-binding protein1 expression is tightly linked to cellular sulfur demand and can reduce sensitivity to stresses requiring glutathione for tolerance. PLANT PHYSIOLOGY 2009; 151:768-81. [PMID: 19710230 PMCID: PMC2754620 DOI: 10.1104/pp.109.144808] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 08/24/2009] [Indexed: 05/22/2023]
Abstract
Selenium-Binding Protein1 (SBP1) gene expression was studied in Arabidopsis (Arabidopsis thaliana) seedlings challenged with several stresses, including cadmium (Cd), selenium {selenate [Se(VI)] and selenite [Se(IV)]}, copper (Cu), zinc (Zn), and hydrogen peroxide (H(2)O(2)) using transgenic lines expressing the luciferase (LUC) reporter gene under the control of the SBP1 promoter. In roots and shoots of SBP1LUC lines, LUC activity increased in response to Cd, Se(VI), Cu, and H(2)O(2) but not in response to Se(IV) or Zn. The pattern of expression of SBP1 was similar to that of PRH43, which encodes the 5'-Adenylylphosphosulfate Reductase2, a marker for the induction of the sulfur assimilation pathway, suggesting that an enhanced sulfur demand triggers SBP1 up-regulation. Correlated to these results, SBP1 promoter showed enhanced activity in response to sulfur starvation. The sulfur starvation induction of SBP1 was abolished by feeding the plants with glutathione (GSH) and was enhanced when seedlings were treated simultaneously with buthionine sulfoxide, which inhibits GSH synthesis, indicating that GSH level participates in the regulation of SBP1 expression. Changes in total GSH level were observed in seedlings challenged with Cd, Se(VI), and H(2)O(2). Accordingly, cad2-1 seedlings, affected in GSH synthesis, were more sensitive than wild-type plants to these three stresses. Moreover, wild-type and cad2-1 seedlings overexpressing SBP1 showed a significant enhanced tolerance to Se(VI) and H(2)O(2) in addition to the previously described resistance to Cd, highlighting that SBP1 expression decreases sensitivity to stress requiring GSH for tolerance. These results are discussed with regard to the potential regulation and function of SBP1 in plants.
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Affiliation(s)
- Véronique Hugouvieux
- Laboratoire de Physiologie Cellulaire Végétale, UMR 5168, Commissariat à l'Energie Atomique/CNRS/Université Joseph-Fourier/INRA, Institut de Recherches en Technologies et Sciences pour le Vivant, Commissariat à l'Energie Atomique-Grenoble, 38054 Grenoble cedex 9, France.
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840
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Goupil P, Souguir D, Ferjani E, Faure O, Hitmi A, Ledoigt G. Expression of stress-related genes in tomato plants exposed to arsenic and chromium in nutrient solution. JOURNAL OF PLANT PHYSIOLOGY 2009; 166:1446-52. [PMID: 19375817 DOI: 10.1016/j.jplph.2009.01.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 01/07/2009] [Accepted: 01/08/2009] [Indexed: 05/04/2023]
Abstract
The molecular responses of hydroponically cultivated tomato plants to As(V) or Cr(VI) were assessed by transcript accumulation analysis of genes coding for products potentially involved in heavy metal tolerance. A quantitative real-time PCR experiment was performed with Hsp90-1, MT2- and GR1-like protein genes using RNA isolated from tomato roots or shoots treated for 24h with As(V) or Cr(VI) at concentrations ranging from 80 to 640 microM. Both transient metallic treatments induced Hsp90-1 transcript accumulation in tomato plants. MT2- and GR1-like transcripts accumulated in tomato roots treated with As(V) but were only slightly affected by Cr(VI) treatment. Tomatoes showed phenotypic symptoms to heavy metal toxicity when plants were exposed to Cr(VI) but not As(V). Plant lethality was observed at 1280 microM Cr(VI), indicating that tomatoes were more tolerant to As than Cr stress under the experimental conditions used here.
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Affiliation(s)
- Pascale Goupil
- Laboratoire de Physiologie et Génétique végétales, ERTAC-UMR INRA, Université Blaise Pascal-Clermont II, Campus universitaire des Cézeaux, 24, avenue des Landais, 63177 Aubière cedex, France.
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841
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Gómez-Galera S, Rojas E, Sudhakar D, Zhu C, Pelacho AM, Capell T, Christou P. Critical evaluation of strategies for mineral fortification of staple food crops. Transgenic Res 2009; 19:165-80. [PMID: 19685153 DOI: 10.1007/s11248-009-9311-y] [Citation(s) in RCA: 173] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 07/25/2009] [Indexed: 11/30/2022]
Abstract
Staple food crops, in particular cereal grains, are poor sources of key mineral nutrients. As a result, the world's poorest people, generally those subsisting on a monotonous cereal diet, are also those most vulnerable to mineral deficiency diseases. Various strategies have been proposed to deal with micronutrient deficiencies including the provision of mineral supplements, the fortification of processed food, the biofortification of crop plants at source with mineral-rich fertilizers and the implementation of breeding programs and genetic engineering approaches to generate mineral-rich varieties of staple crops. This review provides a critical comparison of the strategies that have been developed to address deficiencies in five key mineral nutrients-iodine, iron, zinc, calcium and selenium-and discusses the most recent advances in genetic engineering to increase mineral levels and bioavailability in our most important staple food crops.
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Affiliation(s)
- Sonia Gómez-Galera
- Department of Vegetal Production and Forestry Science, ETSEA, University of Lleida, 25198 Lleida, Spain.
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842
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Abstract
NRAMP (natural resistance-associated macrophage protein) homologues are evolutionarily conserved bivalent metal transporters. In Arabidopsis, AtNRAMP3 and AtNRAMP4 play a key role in iron nutrition of the germinating plantlet by remobilizing vacuolar iron stores. In the present paper we describe the molecular and physiological characterization of AtNRAMP6. AtNRAMP6 is predominantly expressed in the dry seed embryo and to a lesser extent in aerial parts. Its promoter activity is found diffusely distributed in cotyledons and hypocotyl, as well as in the vascular tissue region of leaf and flower. We show that the AtNRAMP6 transcript coexists with a partially spliced isoform in all shoot cell types tested. When expressed in yeast, AtNRAMP6, but not its misspliced derivative, increased sensitivity to cadmium without affecting cadmium content in the cell. Likewise, Arabidopsis transgenic plants overexpressing AtNRAMP6 were hypersensitive to cadmium, although plant cadmium content remained unchanged. Consistently, a null allele of AtNRAMP6, named nramp6-1, was more tolerant to cadmium toxicity, a phenotype that was reverted by expressing AtNRAMP6 in the mutant background. We used an AtNRAMP6::HA (where HA is haemagglutinin) fusion, shown to be functional in yeast, to demonstrate through immunoblot analysis of membrane fractions and immunofluorescence localization that, in yeast cells, AtNRAMP6 is targeted to a vesicular-shaped endomembrane compartment distinct from the vacuole or mitochondria. We therefore propose that AtNRAMP6 functions as an intracellular metal transporter, whose presence, when modified, is likely to affect distribution/availability of cadmium within the cell.
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843
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Lefebvre V, Kiani SP, Durand-Tardif M. A focus on natural variation for abiotic constraints response in the model species Arabidopsis thaliana. Int J Mol Sci 2009; 10:3547-82. [PMID: 20111677 PMCID: PMC2812820 DOI: 10.3390/ijms10083547] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 08/04/2009] [Accepted: 08/11/2009] [Indexed: 11/30/2022] Open
Abstract
Plants are particularly subject to environmental stress, as they cannot move from unfavourable surroundings. As a consequence they have to react in situ. In any case, plants have to sense the stress, then the signal has to be transduced to engage the appropriate response. Stress response is effected by regulating genes, by turning on molecular mechanisms to protect the whole organism and its components and/or to repair damage. Reactions vary depending on the type of stress and its intensity, but some are commonly turned on because some responses to different abiotic stresses are shared. In addition, there are multiple ways for plants to respond to environmental stress, depending on the species and life strategy, but also multiple ways within a species depending on plant variety or ecotype. It is regularly accepted that populations of a single species originating from diverse geographic origins and/or that have been subjected to different selective pressure, have evolved retaining the best alleles for completing their life cycle. Therefore, the study of natural variation in response to abiotic stress, can help unravel key genes and alleles for plants to cope with their unfavourable physical and chemical surroundings. This review is focusing on Arabidopsis thaliana which has been largely adopted by the global scientific community as a model organism. Also, tools and data that facilitate investigation of natural variation and abiotic stress encountered in the wild are set out. Characterization of accessions, QTLs detection and cloning of alleles responsible for variation are presented.
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Affiliation(s)
- Valérie Lefebvre
- INRA/IJPB, Genetics and Plant Breeding Laboratory, UR 254, Route de St Cyr, F-78000 Versailles, France; E-Mails:
(V.L.);
(S.P.K.)
| | - Seifollah Poormohammad Kiani
- INRA/IJPB, Genetics and Plant Breeding Laboratory, UR 254, Route de St Cyr, F-78000 Versailles, France; E-Mails:
(V.L.);
(S.P.K.)
| | - Mylène Durand-Tardif
- INRA/IJPB, Genetics and Plant Breeding Laboratory, UR 254, Route de St Cyr, F-78000 Versailles, France; E-Mails:
(V.L.);
(S.P.K.)
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844
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Lyubenova L, Nehnevajova E, Herzig R, Schröder P. Response of antioxidant enzymes in Nicotiana tabacum clones during phytoextraction of heavy metals. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2009; 16:573-81. [PMID: 19440744 DOI: 10.1007/s11356-009-0175-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Accepted: 03/24/2009] [Indexed: 05/27/2023]
Abstract
BACKGROUND, AIM, AND SCOPE Tobacco, Nicotiana tabacum, is a widely used model plant for growth on heavy-metal-contaminated sites. Its high biomass and deep rooting system make it interesting for phytoextraction. In the present study, we investigated the antioxidative activities and glutathione-dependent enzymes of different tobacco clones optimized for better Cd and Zn accumulation in order to characterize their performance in the field. MAIN FEATURES The improved heavy metal resistance also makes the investigated tobacco clones interesting for understanding the plant defense enzyme system in general. Freshly harvested plant material (N. tabacum leaves) was used to investigate the antioxidative cascade in plants grown on heavy metal contaminated sites with and without amendments of different ammonium nitrate and ammonium sulfate fertilizers. MATERIALS AND METHODS Plants were grown on heavily polluted soils in north-east Switzerland. Leaves were harvested at the field site and directly deep frozen in liquid N(2). Studies were concentrated on the antioxidative enzymes of the Halliwell-Asada cycle, and spectrophotometric measurements of catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), superoxide dismutase (SOD, EC 1.15.1.1), glutathione peroxidase (GPX, EC 1.11.1.9), glutathione reductase (GR, EC 1.6.4.2), glutathione S-transferase (GST, EC 2.5.1.18) were performed. RESULTS AND DISCUSSION We tried to explain the relationship between fertilizer amendments and the activity of the enzymatic defense systems. When tobacco (N. tabacum) plants originating from different mutants were grown under field conditions with varying fertilizer application, the uptake of cadmium and zinc from soil increased with increasing biomass. Depending on Cd and Zn uptake, several antioxidant enzymes showed significantly different activities. Whereas SOD and CAT were usually elevated, several other enzymes, and isoforms of GST were strongly inhibited. CONCLUSIONS Heavy metal uptake represents severe stress to plants, and specific antioxidative enzymes are induced at the cost of more general reactions of the Halliwell-Asada cycle. In well-supplied plants, the glutathione level remains more or less unchanged. The lack of certain glutathione S-transferases upon exposure to heavy metals might be problematic in cases when organic pollutants coincide with heavy metal pollution. When planning phytoremediation of sites, mixed pollution scenarios have to be foreseen and plants should be selected according to both, their stress resistance and hyperaccumulative capacity.
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Affiliation(s)
- Lyudmila Lyubenova
- Department Microbe Plant Interactions, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuerberg, Germany
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845
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Verbruggen N, Hermans C, Schat H. Mechanisms to cope with arsenic or cadmium excess in plants. CURRENT OPINION IN PLANT BIOLOGY 2009; 12:364-72. [PMID: 19501016 DOI: 10.1016/j.pbi.2009.05.001] [Citation(s) in RCA: 398] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 04/30/2009] [Accepted: 05/04/2009] [Indexed: 05/20/2023]
Abstract
The metalloid arsenic and the heavy metal cadmium have no demonstrated biological function in plants. Both elements are highly toxic and of major concern with respect to their accumulation in soils, in the food-chain or in drinking water. Arsenate is taken up by phosphate transporters and rapidly reduced to arsenite, As(III). In reducing environments, As(III) is taken up by aquaporin nodulin 26-like intrinsic proteins. Cd(2+) enters the root via essential metal uptake systems. As(III) and Cd(2+) share some similarity between their toxicology and sequestration machineries. Recent progress in understanding the mechanisms of As and Cd uptake and detoxification is presented, including the elucidation of why rice takes up so much arsenic from soil and of mechanisms of As and Cd hypertolerance.
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Affiliation(s)
- Nathalie Verbruggen
- Laboratoire de Physiologie et de Génétique Moléculaire des Plantes, Faculté des Sciences, Université Libre de Bruxelles, Campus Plaine, Brussels, Belgium.
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846
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Ghasemi R, Ghaderian SM, Krämer U. Accumulation of Nickel in Trichomes of a Nickel Hyperaccumulator Plant,Alyssum inflatum. Northeast Nat (Steuben) 2009. [DOI: 10.1656/045.016.0507] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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847
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Maathuis FJM. Physiological functions of mineral macronutrients. CURRENT OPINION IN PLANT BIOLOGY 2009; 12:250-8. [PMID: 19473870 DOI: 10.1016/j.pbi.2009.04.003] [Citation(s) in RCA: 393] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 04/22/2009] [Accepted: 04/22/2009] [Indexed: 05/20/2023]
Abstract
Plants require calcium, magnesium, nitrogen, phosphorous, potassium and sulfur in relatively large amounts (>0.1% of dry mass) and each of these so-called macronutrients is essential for a plant to complete its life cycle. Normally, these minerals are taken up by plant roots from the soil solution in ionic form with the metals Ca(2+), Mg(2+) and K(+) present as free cations, P and S as their oxyanions phosphate (PO(4)(3-)) and sulfate (SO(4)(2-)) and N as anionic nitrate (NO(3)(-)) or cation ammonium (NH(4)(+)). Recently, important progress has been made in identifying transport and regulatory mechanisms for macronutrients and the mechanisms of uptake and distribution. These and the main physiological roles of each nutrient will be discussed.
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848
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Palmer CM, Guerinot ML. Facing the challenges of Cu, Fe and Zn homeostasis in plants. Nat Chem Biol 2009; 5:333-40. [PMID: 19377460 DOI: 10.1038/nchembio.166] [Citation(s) in RCA: 291] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Plants have recently moved into the spotlight owing to the growing realization that the world needs solutions to energy and food production that are sustainable and environmentally sound. Iron, copper and zinc are essential for plant growth and development, yet the same properties that make these transition metals indispensable can also make them deadly in excess. Iron and copper are most often used for their redox properties, whereas zinc is primarily used for its ability to act as a Lewis acid. Here we review recent advances in the field of metal homeostasis and integrate the findings on uptake and transport of these three metals.
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Affiliation(s)
- Christine M Palmer
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
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849
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Wang F, Zeng B, Sun Z, Zhu C. Relationship between proline and Hg2+-induced oxidative stress in a tolerant rice mutant. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2009; 56:723-31. [PMID: 18787889 DOI: 10.1007/s00244-008-9226-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 08/18/2008] [Indexed: 05/17/2023]
Abstract
There has been little agreement regarding the mechanism by which proline reduces heavy metal stress. The present work examines the relationship between Hg(2+)-induced oxidative stress and proline accumulation in rice and explores the possible mechanisms through which proline protects against Hg(2+) stress. The effect of proline on alleviation of Hg(2+) toxicity was studied by spectrophotography and enzymatic methods. Hg(2+) induced oxidative stress in rice by increasing lipid peroxidation. Pretreatment of the rice with 2 mM proline for 12 h profoundly alleviated Hg(2+)-induced lipid peroxidation and minimized H(2)O(2) accumulation. Proline pretreatment significantly reduced (p < 0.01) the Hg(2+) content in rice leaves. A comparison of the effects of proline pretreatment on H(2)O(2) accumulation by Hg(2+) and aminotrazole suggested that proline protected cells from Hg(2+)-induced oxidative stress by scavenging reactive oxygen species. The present work demonstrates a protective effect of proline on Hg(2+) toxicity through detoxifying reactive oxygen species, rather than chelating metal ions or maintaining the water balance under Hg(2+) stress.
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Affiliation(s)
- Feijuan Wang
- State Key Laboratory of Plant Physiology & Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
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Krznaric E, Verbruggen N, Wevers JHL, Carleer R, Vangronsveld J, Colpaert JV. Cd-tolerant Suillus luteus: a fungal insurance for pines exposed to Cd. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2009; 157:1581-8. [PMID: 19211178 DOI: 10.1016/j.envpol.2008.12.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 12/23/2008] [Accepted: 12/24/2008] [Indexed: 05/24/2023]
Abstract
Soil metal pollution can trigger evolutionary adaptation in soil-borne organisms. An in vitro screening test showed cadmium adaptation in populations of Suillus luteus (L.: Fr.) Roussel, an ectomycorrhizal fungus of pine trees. Cadmium stress was subsequently investigated in Scots pine (Pinus sylvestris L.) seedlings inoculated with a Cd-tolerant S. luteus, isolated from a heavy metal contaminated site, and compared to plants inoculated with a Cd-sensitive isolate from a non-polluted area. A dose-response experiment with mycorrhizal pines showed better plant protection by a Cd-adapted fungus: more fungal biomass and a higher nutrient uptake at high Cd exposure. In addition, less Cd was transferred to aboveground plant parts. Because of the key role of the ectomycorrhizal symbiosis for tree fitness, the evolution of Cd tolerance in an ectomycorrhizal partner such as S. luteus can be of major importance for the establishment of pine forests on Cd-contaminated soils.
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Affiliation(s)
- Erik Krznaric
- Environmental Biology Group, Centre for Environmental Sciences, Hasselt University, Agoralaan, Gebouw D, 3590 Diepenbeek, Belgium
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