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Moy A, Nkongolo K. Decrypting Molecular Mechanisms Involved in Counteracting Copper and Nickel Toxicity in Jack Pine ( Pinus banksiana) Based on Transcriptomic Analysis. PLANTS (BASEL, SWITZERLAND) 2024; 13:1042. [PMID: 38611570 PMCID: PMC11013723 DOI: 10.3390/plants13071042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024]
Abstract
The remediation of copper and nickel-afflicted sites is challenged by the different physiological effects imposed by each metal on a given plant system. Pinus banksiana is resilient against copper and nickel, providing an opportunity to build a valuable resource to investigate the responding gene expression toward each metal. The objectives of this study were to (1) extend the analysis of the Pinus banksiana transcriptome exposed to nickel and copper, (2) assess the differential gene expression in nickel-resistant compared to copper-resistant genotypes, and (3) identify mechanisms specific to each metal. The Illumina platform was used to sequence RNA that was extracted from seedlings treated with each of the metals. There were 449 differentially expressed genes (DEGs) between copper-resistant genotypes (RGs) and nickel-resistant genotypes (RGs) at a high stringency cut-off, indicating a distinct pattern of gene expression toward each metal. For biological processes, 19.8% of DEGs were associated with the DNA metabolic process, followed by the response to stress (13.15%) and the response to chemicals (8.59%). For metabolic function, 27.9% of DEGs were associated with nuclease activity, followed by nucleotide binding (27.64%) and kinase activity (10.16%). Overall, 21.49% of DEGs were localized to the plasma membrane, followed by the cytosol (16.26%) and chloroplast (12.43%). Annotation of the top upregulated genes in copper RG compared to nickel RG identified genes and mechanisms that were specific to copper and not to nickel. NtPDR, AtHIPP10, and YSL1 were identified as genes associated with copper resistance. Various genes related to cell wall metabolism were identified, and they included genes encoding for HCT, CslE6, MPG, and polygalacturonase. Annotation of the top downregulated genes in copper RG compared to nickel RG revealed genes and mechanisms that were specific to nickel and not copper. Various regulatory and signaling-related genes associated with the stress response were identified. They included UGT, TIFY, ACC, dirigent protein, peroxidase, and glyoxyalase I. Additional research is needed to determine the specific functions of signaling and stress response mechanisms in nickel-resistant plants.
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Affiliation(s)
| | - Kabwe Nkongolo
- Biomolecular Sciences Program, Department of Biology, School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
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Moy A, Czajka K, Michael P, Nkongolo K. Gene expression profiling of Jack Pine (Pinus banksiana) under copper stress: Identification of genes associated with copper resistance. PLoS One 2024; 19:e0296027. [PMID: 38452110 PMCID: PMC10919686 DOI: 10.1371/journal.pone.0296027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 12/05/2023] [Indexed: 03/09/2024] Open
Abstract
Understanding the genetic response of plants to copper stress is a necessary step to improving the utility of plants for environmental remediation and restoration. The objectives of this study were to: 1) characterize the transcriptome of Jack Pine (Pinus banksiana) under copper stress, 2) analyze the gene expression profile shifts of genotypes exposed to copper ion toxicity, and 3) identify genes associated with copper resistance. Pinus banksiana seedlings were treated with 10 mmoles of copper and screened in a growth chamber. There were 6,213 upregulated and 29,038 downregulated genes expressed in the copper resistant genotypes compared to the susceptible genotypes at a high stringency based on the false discovery rate (FDR). Overall, 25,552 transcripts were assigned gene ontology. Among the top upregulated genes, the response to stress, the biosynthetic process, and the response to chemical stimuli terms represented the highest proportion of gene expression for the biological processes. For the molecular function category, the majority of expressed genes were associated with nucleotide binding followed by transporter activity, and kinase activity. The majority of upregulated genes were located in the plasma membrane while half of the total downregulated genes were associated with the extracellular region. Two candidate genes associated with copper resistance were identified including genes encoding for heavy metal-associated isoprenylated plant proteins (AtHIP20 and AtHIP26) and a gene encoding the pleiotropic drug resistance protein 1 (NtPDR1). This study represents the first report of transcriptomic responses of a conifer species to copper ions.
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Affiliation(s)
- Alistar Moy
- Biomolecular Sciences Program, School of Natural Sciences, Laurentian University, Sudbury, Ontario, Canada
| | - Karolina Czajka
- Biomolecular Sciences Program, School of Natural Sciences, Laurentian University, Sudbury, Ontario, Canada
| | - Paul Michael
- Biomolecular Sciences Program, School of Natural Sciences, Laurentian University, Sudbury, Ontario, Canada
| | - Kabwe Nkongolo
- Biomolecular Sciences Program, School of Natural Sciences, Laurentian University, Sudbury, Ontario, Canada
- Department of Biology, School of Natural Sciences, Laurentian University, Sudbury, Ontario, Canada
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Feng Y, Xu J, Wu Z, Qian L, Jiang J, Chen Y. Cyclocarya paliurus for Phytomanagement of Lead-Contaminated Soils. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 106:1003-1008. [PMID: 33772598 DOI: 10.1007/s00128-021-03194-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Cyclocarya paliurus seedlings were cultivated in three types of lead (Pb)-contaminated soils with Pb concentration of 305 ± 17 mg/kg (T1), 1964 ± 59 mg/kg (T2) and 3502 ± 107 mg/kg (T3), respectively. The results showed that after 180 days of cultivation, the contents of exchangeable and carbonate-bound Pb fractions significantly decreased in T1 and T2, but increased in T3. The growth indices of C. paliurus seedlings decreased with increasing Pb concentration; however, no difference was found between that in T1 and in Pb-free soil. The Pb concentration in the roots was an order of magnitude higher than that in the stems and in the leaves. The bioconcentration factor (BCF) of the leaves was the lowest among the three tissues investigated, and decreased with the higher concentration of Pb in the soils. These results suggest that C. paliurus can be used as a sustainable and profitable plant for the phytomanagement of Pb-contaminated soil.
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Affiliation(s)
- Ying Feng
- School of Resources and Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China
- Institution of Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China
| | - Jinghua Xu
- School of Resources and Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China
- Institution of Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China
| | - Ziwei Wu
- School of Resources and Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China
| | - Lianwen Qian
- School of Resources and Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China
- Institution of Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China
| | - Jinping Jiang
- Guangxi Scientific Experiment Center of Mining, Metallurgy and Environment, Guilin University of Technology, Guilin, 541004, China
| | - Yongshan Chen
- School of Resources and Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China.
- Institution of Environmental Science, Quanzhou Normal University, Quanzhou, 362000, China.
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Carrillo JT, Borthakur D. Methods for metal chelation in plant homeostasis: Review. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 163:95-107. [PMID: 33826996 DOI: 10.1016/j.plaphy.2021.03.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 03/20/2021] [Indexed: 05/01/2023]
Abstract
Metal uptake, transport and storage in plants depend on specialized ligands with closely related functions. Individual studies differing by species, nutrient availability, tissue type, etc. are not comprehensive enough to understand plant metal homeostasis in its entirety. A thorough review is required that distinguishes the role of ligands directly involved in chelation from the myriad of plant responses to general stress. Distinguishing between the functions of metal chelating compounds is the primary focus of this review; reactive oxygen species mediation and other aspects of metal homeostasis are also discussed. High molecular weight ligands (polysaccharides, phytochelatin, metallothionein), low molecular weight ligands (nicotianamine, histidine, secondary metabolites) and select studies which demonstrate the complex nature of plant metal homeostasis are explored.
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Affiliation(s)
- James T Carrillo
- University of Hawaii at Manoa, Department of Molecular Biology and Bioengineering, 1955 East-West Road, Agricultural Sciences 218, Honolulu, HI, 96822, USA.
| | - Dulal Borthakur
- University of Hawaii at Manoa, Department of Molecular Biology and Bioengineering, 1955 East-West Road, Agricultural Sciences 218, Honolulu, HI, 96822, USA.
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Fryzova R, Pohanka M, Martinkova P, Cihlarova H, Brtnicky M, Hladky J, Kynicky J. Oxidative Stress and Heavy Metals in Plants. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2018; 245:129-156. [PMID: 29032515 DOI: 10.1007/398_2017_7] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Oxidative stress is a pathological process related to not only animal kingdom but also plants. Regarding oxidative stress in plants, heavy metals are frequently discussed as causative stimuli with relevance to ecology. Because heavy metals have broad technological importance, they can easily contaminate the environment. Much of previous effort regarding the harmful impact of the heavy metals was given to their toxicology in the animals and humans. Their implication in plant pathogeneses is less known and remains underestimated.The current paper summarizes basic facts about heavy metals, their distribution in soil, mobility, accumulation by plants, and initiation of oxidative stress including the decline in basal metabolism. The both actual and frontier studies in the field are summarized and discussed. The major pathophysiological pathways are introduced as well and link between heavy metals toxicity and their ability to initiate an oxidative damage is provided. Mobility and bioaccessibility of the metals is also considered as key factors in their impact on oxidative stress development in the plant. The metals like lead, mercury, copper, cadmium, iron, zinc, nickel, vanadium are depicted in the text.Heavy metals appear to be significant contributors to pathological processes in the plants and oxidative stress is probably an important contributor to the effect. The most sensitive plant species are enlisted and discussed in this review. The facts presented here outline next effort to investigate pathological processes in the plants.
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Affiliation(s)
- Radka Fryzova
- Department of Geology and Pedology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, Brno, 613 00, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Purkynova 123, Brno, 612 00, Czech Republic
| | - Miroslav Pohanka
- Department of Geology and Pedology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, Brno, 613 00, Czech Republic
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove, 500 01, Czech Republic
| | - Pavla Martinkova
- Central European Institute of Technology, Brno University of Technology, Purkynova 123, Brno, 612 00, Czech Republic
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, Hradec Kralove, 500 01, Czech Republic
| | - Hana Cihlarova
- Department of Geology and Pedology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, Brno, 613 00, Czech Republic
| | - Martin Brtnicky
- Department of Geology and Pedology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, Brno, 613 00, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Purkynova 123, Brno, 612 00, Czech Republic
| | - Jan Hladky
- Department of Geology and Pedology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, Brno, 613 00, Czech Republic
- Central European Institute of Technology, Brno University of Technology, Purkynova 123, Brno, 612 00, Czech Republic
| | - Jindrich Kynicky
- Department of Geology and Pedology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemedelska 3, Brno, 613 00, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Purkynova 123, Brno, 612 00, Czech Republic.
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Independent metal-thiolate cluster formation in C-terminal Cys-rich region of a rice type 1 metallothionein isoform. Int J Biol Macromol 2016; 96:436-441. [PMID: 28013008 DOI: 10.1016/j.ijbiomac.2016.12.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 12/14/2016] [Accepted: 12/16/2016] [Indexed: 11/23/2022]
Abstract
In this study we examined the independent self assembly of metal-binding in C-terminal Cys- rich region of a type 1 metallothionein (MT) isoform from rice (OsMTI-1b). To this end the N-terminal of OsMTI-1b (C-OsMTI-1b) was heterologously expressed in Escherichia coli as fusion protein with glutathione-S-transferase (GST). As compared with control (The E. coli cells containing pET41a without gene), transgenic E. coli cells expressing GST-C-OsMTI-1b accumulated more Ni2+, Cd2+, and Zn2+ from culture medium and showed increased tolerance against these metals. The recombinant GST-C-OsMTI-1b was purified using affinity chromatography. According to in vitro assays the protein GST-C-OsMTI-1b was able to form complexes with Ni2+, Cd2+ and Zn2+. These results demonstrate the formation of independent metal-thiolate cluster at C-terminal Cys-rich region of OsMTI-1b without participation of N-terminal Cys-rich region.
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Cloning and characterization of metallothionein gene (HcMT) from Halostachys caspica and its expression in E. coli. Gene 2016; 585:221-7. [PMID: 27032460 DOI: 10.1016/j.gene.2016.03.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/11/2016] [Accepted: 03/21/2016] [Indexed: 02/06/2023]
Abstract
Halostachys caspica is a short shrub distributed in the semi-arid and saline-alkali area, which evolved various mechanisms for modulating salt and metal level. In the present study, a Type 2 metallothionein (HcMT) gene was cloned from the salt induced suppression subtractive hybridization (SSH) cDNA library of H.caspica. Quantitative real time PCR (qRT-PCR) analysis indicated that HcMT gene was up-regulated under the stress of Cu(2+), Zn(2+) and Cd(2+), and the tolerance of E. coli strain harboring with the recombinant HcMT (pET-32a-HcMT) to Cu(2+), Zn(2+) and Cd(2+) was enhanced compared to strain with control vector (pET-32a). Moreover, the purified TrxA-HcMT fusion protein from E. coli cells grown in the presence of 0.3mM CuSO4, 0.3mM ZnSO4, or 0.1mM CdCl2 could bind more metal ions than TrxA alone. The predicted 3D structure showed that HcMT could form a single metal-thiolate cluster, which confers the ability to bind five divalent metal ions through fourteen cysteine residues. These data indicate that HcMT may be involved in processes of metal tolerance in H. caspica and could be employed as a potential candidate for heavy metal phytoremediation.
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Functional characterization of a type 3 metallolthionein isoform (OsMTI-3a) from rice. Int J Biol Macromol 2015; 73:154-9. [DOI: 10.1016/j.ijbiomac.2014.10.067] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 11/22/2022]
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Tomas M, Pagani MA, Andreo CS, Capdevila M, Bofill R, Atrian S. His-containing plant metallothioneins: comparative study of divalent metal-ion binding by plant MT3 and MT4 isoforms. J Biol Inorg Chem 2014; 19:1149-64. [PMID: 24951240 DOI: 10.1007/s00775-014-1170-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 05/31/2014] [Indexed: 11/30/2022]
Abstract
Metallothioneins (MTs) are a superfamily of Cys-rich, low-molecular weight metalloproteins that bind heavy metal ions. These cytosolic metallopeptides, which exist in most living organisms, are thought to be involved in metal homeostasis, metal detoxification, and oxidative stress protection. In this work, we characterise the Zn(II)- and Cd(II)-binding abilities of plant type 3 and type 4 MTs identified in soybean and sunflower, both of them being His-containing peptides. The recombinant metal-MT complexes synthesised in Zn(II) or Cd(II)-enriched Escherichia coli cultures have been analysed by ESI-MS, and CD, ICP-AES, and UV spectroscopies. His-to-Ala type 3 MT mutants have also been constructed and synthesised for the study of the role of His in divalent metal ion coordination. The results show comparable divalent metal-binding capacities for the MTs of type 3, and suggest, for the first time, the participation of their conserved C-term His residues in metal binding. Interesting features for the Zn(II)-binding abilities of type 4 MTs are also reported, as their variable His content may be considered crucial for their biological performance.
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Affiliation(s)
- Mireia Tomas
- Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08093, Barcelona, Spain
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Moulis JM, Bourguignon J, Catty P. Cadmium. BINDING, TRANSPORT AND STORAGE OF METAL IONS IN BIOLOGICAL CELLS 2014. [DOI: 10.1039/9781849739979-00695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Cadmium is not an essential element for life. It is geologically marginal but anthropogenic activities have contributed significantly to its dispersion in the environment and to cadmium exposure of living species. The natural speciation of the divalent cation Cd2+ is dominated by its high propensity to bind to sulfur ligands, but Cd2+ may also occupy sites providing imidazole and carboxylate ligands. It binds to cell walls by passive adsorption (bio-sorption) and it may interact with surface receptors. Cellular uptake can occur by ion mimicry through a variety of transporters of essential divalent cations, but not always. Once inside cells, Cd2+ preferentially binds to thiol-rich molecules. It can accumulate in intracellular vesicles. It may also be transported over long distances within multicellular organisms and be trapped in locations devoid of efficient excretion systems. These locations include the renal cortex of animals and the leaves of hyper-accumulating plants. No specific regulatory mechanism monitors Cd2+ cellular concentrations. Thiol recruitment by cadmium is a major interference mechanism with many signalling pathways that rely on thiolate-disulfide equilibria and other redox-related processes. Cadmium thus compromises the antioxidant intracellular response that relies heavily on molecules with reactive thiolates. These biochemical features dominate cadmium toxicity, which is complex because of the diversity of the biological targets and the consequent pleiotropic effects. This chapter compares the cadmium-handling systems known throughout phylogeny and highlights the basic principles underlying the impact of cadmium in biology.
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Affiliation(s)
- Jean-Marc Moulis
- CEA, Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire Chimie et Biologie des Métaux 17 rue des Martyrs F-38054 Grenoble France
- CNRS UMR5249 F-38054 Grenoble France
- Université Joseph Fourier-Grenoble I UMR5249 F-38041 Grenoble France
| | - Jacques Bourguignon
- CEA, Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire Physiologie Cellulaire et Végétale F-38054 Grenoble France
- CNRS UMR5168 F-38054 Grenoble France
- Université Joseph Fourier-Grenoble I UMR5168 F-38041 Grenoble France
- INRA USC1359 F-38054 Grenoble France
| | - Patrice Catty
- CEA, Institut de Recherches en Technologies et Sciences pour le Vivant, Laboratoire Chimie et Biologie des Métaux 17 rue des Martyrs F-38054 Grenoble France
- CNRS UMR5249 F-38054 Grenoble France
- Université Joseph Fourier-Grenoble I UMR5249 F-38041 Grenoble France
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Tang L, Qiu R, Tang Y, Wang S. Cadmium–zinc exchange and their binary relationship in the structure of Zn-related proteins: a mini review. Metallomics 2014; 6:1313-23. [DOI: 10.1039/c4mt00080c] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we give an overview of ongoing work on discovering the structural mechanisms of Cd–Zn exchange and the potentially diverse roles of Cd at Zn functional sites in proteins.
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Affiliation(s)
- Lu Tang
- School of Environmental Science and Engineering
- Sun Yat-Sen University
- Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology
- Guangzhou 510275, China
| | - Rongliang Qiu
- School of Environmental Science and Engineering
- Sun Yat-Sen University
- Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology
- Guangzhou 510275, China
| | - Yetao Tang
- School of Environmental Science and Engineering
- Sun Yat-Sen University
- Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology
- Guangzhou 510275, China
| | - Shizhong Wang
- School of Environmental Science and Engineering
- Sun Yat-Sen University
- Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology
- Guangzhou 510275, China
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Leitenmaier B, Küpper H. Compartmentation and complexation of metals in hyperaccumulator plants. FRONTIERS IN PLANT SCIENCE 2013; 4:374. [PMID: 24065978 PMCID: PMC3778397 DOI: 10.3389/fpls.2013.00374] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 09/03/2013] [Indexed: 05/18/2023]
Abstract
Hyperaccumulators are being intensely investigated. They are not only interesting in scientific context due to their "strange" behavior in terms of dealing with high concentrations of metals, but also because of their use in phytoremediation and phytomining, for which understanding the mechanisms of hyperaccumulation is crucial. Hyperaccumulators naturally use metal accumulation as a defense against herbivores and pathogens, and therefore deal with accumulated metals in very specific ways of complexation and compartmentation, different from non-hyperaccumulator plants and also non-hyperaccumulated metals. For example, in contrast to non-hyperaccumulators, in hyperaccumulators even the classical phytochelatin-inducing metal, cadmium, is predominantly not bound by such sulfur ligands, but only by weak oxygen ligands. This applies to all hyperaccumulated metals investigated so far, as well as hyperaccumulation of the metalloid arsenic. Stronger ligands, as they have been shown to complex metals in non-hyperaccumulators, are in hyperaccumulators used for transient binding during transport to the storage sites (e.g., nicotianamine) and possibly for export of Cu in Cd/Zn hyperaccumulators [metallothioneins (MTs)]. This confirmed that enhanced active metal transport, and not metal complexation, is the key mechanism of hyperaccumulation. Hyperaccumulators tolerate the high amount of accumulated heavy metals by sequestering them into vacuoles, usually in large storage cells of the epidermis. This is mediated by strongly elevated expression of specific transport proteins in various tissues from metal uptake in the shoots up to the storage sites in the leaf epidermis. However, this mechanism seems to be very metal specific. Non-hyperaccumulated metals in hyperaccumulators seem to be dealt with like in non-hyperaccumulator plants, i.e., detoxified by binding to strong ligands such as MTs.
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Affiliation(s)
| | - Hendrik Küpper
- Fachbereich Biologie, Universität KonstanzKonstanz, Germany
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Leszczyszyn OI, Imam HT, Blindauer CA. Diversity and distribution of plant metallothioneins: a review of structure, properties and functions. Metallomics 2013; 5:1146-69. [DOI: 10.1039/c3mt00072a] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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