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Yang H, Zhao Z, Li H, Wang L. Metal binding feature of copper‒induced metallothionein from freshwater crab Sinopotamon henanense reveals its Cu‒thionein character. Protein Expr Purif 2024; 221:106519. [PMID: 38830441 DOI: 10.1016/j.pep.2024.106519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 05/24/2024] [Accepted: 05/30/2024] [Indexed: 06/05/2024]
Abstract
Sinopotamon Henanense expresses two metal‒induced metallothioneins (MTs), Cd‒induced MT and Cu‒induced MT (ShCuMT). The Cd‒induced MT has been characterized as a Cd‒thiolate MT. However, it is unknown whether ShCuMT is a Cu‒thiolate MT. In the present study, ShCuMT was expressed heterologously in Escherichia coli and purified by Ni‒NTA column and superdex‒75 column. And its metal‒binding feature was evaluated by DTNB reaction, circular dichroism spectroscopy (CD), isothermal microtitration (ITC), electrospray flight mass spectrometry (ESI‒TOF‒MS), and matrix‒assisted laser desorption ionization flight mass spectrometry (MALDI‒TOF‒MS). Bioinformatics analysis demonstrated that ShCuMT possessed the cysteine‒triplet motif of a Cu‒specific MT. Expression and purification of ShCuMT illustrated that SUMO tag used as the production system for ShCuMT resulted in a high production yield. The stability order of ShCuMT binding metal ions were Cu (Ⅰ) > Cd (Ⅱ) > Zn (Ⅱ). The CD spectrum indicated that ShCuMT binding with Cu (I) exhibited a compact thiol metal clusters structure. Besides, there emerged no a visible nickel‒thiol absorption after Ni‒NTA column affinity chromatography. The ITC results implied that Cu‒ShCuMT possessed the optimal thermodynamic conformation and the highest stoichiometric number of Cu (Ⅰ). Overall, the results suggested that SUMO fusion system is a robust and inexpensive approach for ShCuMT expression and Ni‒NTA column had no influence on metal binding of ShCuMT and Cu(Ⅰ) was considered its cognate metal ion, and ShCuMT possessed canonical Cu‒thiolate characteristics. The metal binding feature of ShCuMT reported here contributes to elucidating the structure‒function relationship of ShCuMT in S. Henanense.
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Affiliation(s)
- Huizhen Yang
- Shanxi Key Laboratory for Modernization of TCVM/ College of Veterinary Medicine, Shanxi Agriculture University, Jinzhong, Shanxi Province, 030800, China.
| | - Ziyan Zhao
- Shanxi Key Laboratory for Modernization of TCVM/ College of Veterinary Medicine, Shanxi Agriculture University, Jinzhong, Shanxi Province, 030800, China
| | - Hongquan Li
- Shanxi Key Laboratory for Modernization of TCVM/ College of Veterinary Medicine, Shanxi Agriculture University, Jinzhong, Shanxi Province, 030800, China.
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China.
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Paulo AM, Caetano NS, Marques APGC. The Potential of Bioaugmentation-Assisted Phytoremediation Derived Maize Biomass for the Production of Biomethane via Anaerobic Digestion. PLANTS (BASEL, SWITZERLAND) 2023; 12:3623. [PMID: 37896085 PMCID: PMC10610220 DOI: 10.3390/plants12203623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/17/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023]
Abstract
Anthropogenic behaviors are causing the severe build-up of heavy metal (HM) pollutants in the environment, particularly in soils. Amongst a diversity of remediation technologies, phytoremediation is an environmentally friendly technology that, when coupling tolerant plants to selected rhizospheric microorganisms, can greatly stimulate HM decontamination of soils. Maize (Zea mays) is a plant with the reported capacity for HM exclusion from contaminated soil but also has energetic importance. In this study, Zea mays was coupled with Rhizophagus irregularis, an arbuscular mycorrhizal fungus (AMF), and Cupriavidus sp. strain 1C2, a plant growth-promoting rhizobacteria (PGPR), as a remediation approach to remove Cd and Zn from an industrial contaminated soil (1.2 mg Cd kg-1 and 599 mg Zn kg-1) and generate plant biomass, by contrast to the conservative development of the plant in an agricultural (with no metal pollution) soil. Biomass production and metal accumulation by Z. mays were monitored, and an increase in plant yield of ca. 9% was observed after development in the contaminated soil compared to the soil without metal contamination, while the plants removed ca. 0.77% and 0.13% of the Cd and Zn initially present in the soil. The resulting biomass (roots, stems, and cobs) was used for biogas generation in several biomethane (BMP) assays to evaluate the potential end purpose of the phytoremediation-resulting biomass. It was perceptible that the HMs existent in the industrial soil did not hinder the anaerobic biodegradation of the biomass, being registered biomethane production yields of ca. 183 and 178 mL of CH4 g-1 VS of the complete plant grown in non-contaminated and contaminated soils, respectively. The generation of biomethane from HM-polluted soils' phytoremediation-derived maize biomass represents thus a promising possibility to be a counterpart to biogas production in an increasingly challenging status of renewable energy necessities.
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Affiliation(s)
- Ana M. Paulo
- CBQF—Centro de Biotecnologia e Química Fina—Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, 4169-005 Porto, Portugal;
| | - Nídia S. Caetano
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal;
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- CIETI/ISEP—Centro de Inovação em Engenharia e Tecnologia Industrial/Instituto Superior de Engenharia, Politécnico do Porto, Rua Dr. António Bernardino de Almeida 431, 4249-015 Porto, Portugal
| | - Ana P. G. C. Marques
- CBQF—Centro de Biotecnologia e Química Fina—Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, 4169-005 Porto, Portugal;
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Yan K, Ablimit M, Liu S, Liu Z, Wang Y. A novel metallothionein gene HcMT from halophyte shrub Halostachys caspica respond to cadmium and sodium stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 201:107763. [PMID: 37301187 DOI: 10.1016/j.plaphy.2023.107763] [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: 02/17/2023] [Revised: 04/23/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
Cadmium (Cd) and sodium (Na) are two of the most phytotoxic metallic elements causing environmental and agricultural problems. Metallothioneins (MTs) play an important role in the adaptation to abiotic stress. We previously isolated a novel type 2 MT gene from Halostachys caspica (H. caspica), named HcMT, which responded to metal and salt stress. To understand the regulatory mechanisms controlling HcMT expression, we cloned the HcMT promoter and characterized its tissue-specific and spatiotemporal expression patterns. β-Glucuronidase (GUS) activity analysis showed that the HcMT promoter was responsive to CdCl2, CuSO4, ZnSO4 and NaCl stress. Therefore, we further investigated the function of HcMT under abiotic stress in yeast and Arabidopsis thaliana (Arabidopsis). In CdCl2, CuSO4 or ZnSO4 stress, HcMT significantly enhanced the metal ions tolerance and accumulation in yeast through function as a metal chelator. Moreover, the HcMT protein also protected yeast cells from NaCl, PEG and hydrogen peroxide (H2O2) toxicity with less effectiveness. However, transgenic Arabidopsis carrying HcMT gene only displayed tolerance to CdCl2 and NaCl, accompanying by higher content of Cd2+ or Na+ and lower H2O2, compared to wild-type (WT) plants. Next, we demonstrated that the recombinant HcMT protein has the ability to bind Cd2+ and the potential of scavenging ROS (reactive oxygen species) in vitro. This result further confirmed that the role of HcMT to influence plants to CdCl2 and NaCl stress may bind metal ions and scavenge ROS. Overall, we described the biological functions of HcMT and developed a metal- and salt-inducible promoter system for using in genetic engineering.
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Affiliation(s)
- Kexin Yan
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017, China.
| | - Mehriban Ablimit
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017, China.
| | - Sai Liu
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017, China.
| | - Zhongyuan Liu
- School of Chemical Engineering, Sichuan University of Science and Engineering, Sichuan, 643000, China.
| | - Yan Wang
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830017, China.
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Ma Y, Xue M, Zhang X, Chen S. Genome-wide analysis of the metallothionein gene family in cassava reveals its role in response to physiological stress through the regulation of reactive oxygen species. BMC PLANT BIOLOGY 2023; 23:227. [PMID: 37118665 PMCID: PMC10142807 DOI: 10.1186/s12870-023-04174-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 03/16/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND Cassava (Manihot esculenta Crantz) is widely planted in tropical and several subtropical regions in which drought, high temperatures, and other abiotic stresses occur. Metallothionein (MT) is a group of conjugated proteins with small molecular weight and rich in cysteine. These proteins play a substantial role in response to physiological stress through the regulation of reactive oxygen species (ROS). However, the biological functions of MT genes in cassava are unknown. RESULTS A total of 10 MeMT genes were identified in the cassava genome. The MeMTs were divided into 3 groups (Types 2-4) based on the contents and distribution of Cys residues. The MeMTs exhibited tissue-specific expression and located on 7 chromosomes. The MeMT promoters contain some hormones regulatory and stresses responsiveness elements. MeMTs were upregulated under hydrogen peroxide (H2O2) treatment and in respond to post-harvest physiological deterioration (PPD). The results were consistent with defense-responsive cis-acting elements in the MeMT promoters. Further, four of MeMTs were selected and silenced by using the virus-induced gene silencing (VIGS) method to evaluate their functional characterization. The results of gene-silenced cassava suggest that MeMTs are involved in oxidative stress resistance, as ROS scavengers. CONCLUSION We identified the 10 MeMT genes, and explore their evolutionary relationship, conserved motif, and tissue-specific expression. The expression profiles of MeMTs under three kinds of abiotic stresses (wounding, low-temperature, and H2O2) and during PPD were analyzed. The tissue-specific expression and the response to abiotic stresses revealed the role of MT in plant growth and development. Furthermore, silenced expression of MeMTs in cassava leaves decreased its tolerance to ROS, consistent with its predicted role as ROS scavengers. In summary, our results suggest an important role of MeMTs in response to physiological stress as well as species adaptation via the regulation of ROS homeostasis.
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Affiliation(s)
- Yanyan Ma
- School of Life Sciences, Hainan University, Haikou, 570228, China
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences/Key Laboratory of Ministry of Agriculture for Germplasm Resources Conservation and Utilization of Cassava, Haikou, 571101, China
| | - Maofu Xue
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences/Key Laboratory of Ministry of Agriculture for Germplasm Resources Conservation and Utilization of Cassava, Haikou, 571101, China
| | - Xiaofei Zhang
- Alliance of Bioversity International and CIAT, Cali, 763537, Colombia
| | - Songbi Chen
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences/Key Laboratory of Ministry of Agriculture for Germplasm Resources Conservation and Utilization of Cassava, Haikou, 571101, China.
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Fan Y, Jiang T, Chun Z, Wang G, Yang K, Tan X, Zhao J, Pu S, Luo A. Zinc affects the physiology and medicinal components of Dendrobium nobile Lindl. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 162:656-666. [PMID: 33780739 DOI: 10.1016/j.plaphy.2021.03.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
The growth of Dendrobium nobile is often influenced by zinc. Here, D. nobile was regularly sprayed with different concentrations (0, 50, 100, 200, 400, 800, 1000, 2000 μmol L-1) of zinc to study its effect on the growth and biosynthesis of medicinal components. Samples were taken at 0, 7, 14, and 21 days to detect physiological and medicinal components. The results showed that the net photosynthetic rate, transpiration rate, stomatal conductance, and Chl A and Chl B levels of leaves first increased and then decreased as the concentration of zinc increased. At 400 μmol L-1 concentration, these parameters reached their maximum values. Thus, a certain dose of zinc could promote the photosynthesis of D. nobile. There was an obvious increase in the synthesis of superoxide dismutase (SOD), while the content of ascorbate peroxidase and ascorbic acid (AsA) were the highest after treatment with 400 μmol L-1 zinc. Maximum levels of polysaccharides and polyphenols were observed on day 7 and 14, respectively, at a zinc concentration of 400 μmol L-1. These results suggest that exogenous zinc may promote the accumulation of medicinal components in D. nobile. It was also found that polysaccharides could combine well with zinc to form a polysaccharide-zinc chelate and transform inorganic zinc into organic form, which is stored in the form of polysaccharide-Zn and is known to reduce the damage induced by Zn stress.
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Affiliation(s)
- Yijun Fan
- Department of Landscape Plants, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ting Jiang
- Department of Landscape Plants, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ze Chun
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Gang Wang
- College of Forest, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Kaigang Yang
- Department of Landscape Plants, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xueyan Tan
- Department of Landscape Plants, Sichuan Agricultural University, Chengdu, 611130, China
| | - Juan Zhao
- Department of Landscape Plants, Sichuan Agricultural University, Chengdu, 611130, China
| | - Shangrao Pu
- Department of Landscape Plants, Sichuan Agricultural University, Chengdu, 611130, China
| | - Aoxue Luo
- Department of Landscape Plants, Sichuan Agricultural University, Chengdu, 611130, China.
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Yang HZ, Wang L, He YJ, Jing WX, Ma WL, Chen CM, Wang L. Analysis of spectrometry and thermodynamics of the metallothionein in freshwater crab Sinopotamon henanense for its binding ability with different metals. CHEMOSPHERE 2020; 246:125670. [PMID: 31918077 DOI: 10.1016/j.chemosphere.2019.125670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 06/10/2023]
Abstract
The metal binding nature of heterologously expressed metallothionein of Sinopotamon henanense (ShMT) had been demonstrated previously. In this study, we analysed the stoichiometry of ShMT yielded in vivo and exchange reactions of the Zn-ShMT with Cd2+, Pb2+ and Cu2+in vitro via electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), circular dichroism (CD) spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), and isothermal titration calorimetry (ITC). The results of ESI-TOF-MS analyses showed that metal-ShMT synthesized in vivo had three major forms, namely Zn15-, Cd9-, and Pb5-ShMT. The ITC analyses of exchange reactions demonstrated that Zn-ShMT exhibited up to 6, 6, and 7 binding sites for Cd2+, Pb2+ and Cu2+. By the analyses of the UV and CD spectra in the substitution experiments showed that the geometric structural stability of metal-ShMT could be influenced when excess of over 6, 6, or 7 equivalents of Cd2+, Pb2+, or Cu2+ were added into Zn-ShMT. Although both the reconstructed apo-ShMT and substituted Zn-ShMT with three metal ions fitted the same M6Ⅱ- and M7Ⅰ-ShMT binding models for divalent and monovalent metals, the differences in their thermodynamic data suggested that discrepancies exit in their physiological functions. These results suggested that ShMT yielded in vivo had a higher storage capability for Zn2+ and a uptake ability for Cd2+, and Zn-ShMT was more easy to release Zn2+ as well as to uptake Cd2+, Cu2+, or Pb2+. The results presented in this work will be very valuable to understand the function(s) of ShMT not only in a normal physiological condition but also in the presence of non-essential metals in crabs.
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Affiliation(s)
- Hui Zhen Yang
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China
| | - Lu Wang
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China
| | - Yong J He
- Agricultural Processing Institution, Shanxi Academy of Agricultural Sciences, Shanxi Province, China
| | - Wei X Jing
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China
| | - Wen L Ma
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China
| | - Chien M Chen
- Department of Environmental Resources Management, Chia Nan University of Pharmacy & Science, Taiwan.
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China.
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Yang HZ, Gu WJ, Chen W, Hwang JS, Wang L. Metal binding characterization of heterologously expressed metallothionein of the freshwater crab Sinopotamon henanense. CHEMOSPHERE 2019; 235:926-934. [PMID: 31299706 DOI: 10.1016/j.chemosphere.2019.06.097] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/11/2019] [Accepted: 06/12/2019] [Indexed: 06/10/2023]
Abstract
We characterized the metal tolerance of recombinant strains harboring metallothionein from the freshwater crab Sinopotamon henanense (ShMT) in vivo and metal binding properties of ShMT purified in vitro. The recombinant strains harboring ShMT were exposed to 0.1 mM Cd2+, 0.3 mM Cu2+, 0.5 mM Pb2+, and 0.8 mM Zn2+. The growth curves and spot assays of recombinant strains and the contents of heavy metal ions were analysed in the media supplemented with above metal ions provided to recombinant E. coli synthesis. The structural characteristics of the Cd-, Cu-, Pb-, and Zn-ShMT were determined through ultraviolet spectroscopy (UV-vis), circular dichroism (CD), and isothermal titration calorimetry (ITC). The in vivo results showed that, compared to control strains, recombinant strains tolerated Cd2+, Cu2+, Pb2+, and Zn2+. Furthermore, the contents of Cd2+ and Pb2+ in media decreased substantially. In vitro and the Cd-ShMT had a higher degree of folding compactness in solution. 5,5'-Dithiobis-(2-nitrobenzoic) acid (DTNB) reaction and ITC results demonstrated that ShMT yielded Cd6-, Cu7-, and Pb6-ShMT. The binding stability order was Cu-ShMT > Cd-ShMT > Pb-ShMT > Zn-ShMT. Overall, ShMT is a canonical crustacean MT and is defined as a Cd-specific MT isoform that functions mainly in a detoxifying Cd2+ and Pb2+ and in regulating Zn2+ homeostasis in S. henanense. This research on the metal binding properties of ShMT provides a better understanding of the physiological function of ShMT reducing heavy metal bioavailability and by regulating essential trace metals.
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Affiliation(s)
- Hui Zhen Yang
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China
| | - Wen J Gu
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China
| | - Wei Chen
- Medical School, Duke University, USA
| | - Jiang S Hwang
- School of Life Science, Taiwan Ocean University, Taiwan
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, Shanxi Province, 030006, China.
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Agnello AC, Potysz A, Fourdrin C, Huguenot D, Chauhan PS. Impact of pyrometallurgical slags on sunflower growth, metal accumulation and rhizosphere microbial communities. CHEMOSPHERE 2018; 208:626-639. [PMID: 29894964 DOI: 10.1016/j.chemosphere.2018.06.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 05/07/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
Metallurgical exploitation originates metal-rich by-products termed slags, which are often disposed in the environment being a source of heavy metal pollution. Despite the environmental risk that this may pose for living organisms, little is known about the impact of slags on biotic components of the ecosystem like plants and rhizosphere microbial communities. In this study, metal-rich (Cu, Pb, Zn) granulated slags (GS) derived from Cu production process, were used for a leaching test in the presence of the soil pore solution, showing that soil solution enhanced the release of Cu from GS. A pot experiment was conducted using as growing substrate for sunflower (Helianthus annuus) a 50% w/w mix of an agricultural soil and GS. Bioavailability of metals in soil was, in increasing order: Pb < Zn < Cu. Sunflower was able to grow in the presence of GS and accumulated metals preferentially in above-ground tissues. Microbial diversity was assessed in rhizosphere and bulk soil using community level physiological profiling (CLPP) and 16S rRNA gene based denaturing gradient gel electrophoresis (DGGE) analyses, which demonstrated a shift in the diversity of microbial communities induced by GS. Overall, these results suggest that metallurgical wastes should not be considered inert when dumped in the soil. Implications from this study are expected to contribute to the development of sustainable practices for the management of pyrometallurgical slags, possibly involving a phytomanagement approach.
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Affiliation(s)
- A C Agnello
- Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 5 Bd Descartes 77454 Marne-la-Vallée, France.
| | - A Potysz
- Institute of Geological Sciences, University of Wrocław, Cybulskiego 30, 50-205 Wrocław, Poland.
| | - C Fourdrin
- Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 5 Bd Descartes 77454 Marne-la-Vallée, France.
| | - D Huguenot
- Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 5 Bd Descartes 77454 Marne-la-Vallée, France.
| | - P S Chauhan
- CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, U.P. 226001, India.
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Huang Y, Fang Y, Long X, Liu L, Wang J, Zhu J, Ma Y, Qin Y, Qi J, Hu X, Tang C. Characterization of the rubber tree metallothionein family reveals a role in mitigating the effects of reactive oxygen species associated with physiological stress. TREE PHYSIOLOGY 2018; 38:911-924. [PMID: 29425342 DOI: 10.1093/treephys/tpy003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 01/28/2018] [Indexed: 05/15/2023]
Abstract
Metallothioneins (MTs) as reactive oxygen species (ROS) scavengers play important roles in stress response and heavy metal homeostasis. In Hevea brasiliensis (the para rubber tree that is the source of commercial natural rubber) and in other trees, the functions of MTs are not well understood. Latex exudes when the rubber tree is tapped. The flow of latex and its regeneration can be enhanced by tapping, wounding and ethylene treatment, all of which produce ROS as a by-product. Here, we show the presence of four MT genes in H. brasiliensis, comprising three Type 2 (HbMT2, -2a and -2b) and one Type 3 (HbMT3L) isoforms, representing one of the smallest MT gene families among angiosperms. The four HbMTs exhibited distinct tissue expression patterns: HbMT2 and HbMT3L mainly in leaves, HbMT2a specifically in flowers and HbMT2b in diverse tissues. The expression of HbMT2b, an isoform present in latex, decreased significantly in the latex following the stress-inducing treatments of tapping, wounding and ethephon (an ethylene generator). The expressions of the leaf-abundant isoforms, HbMT2 and -3L were up-regulated following pathogenic fungus infection and high-temperature stress, but down-regulated by low-temperature stress. These reactions were consistent with multiple defense- and hormone-responsive cis-acting elements in the HbMT promoters. Nine transcription factors were shown to implicate in the high-temperature responsiveness of HbMT2 and -3L in leaves. Overexpression of HbMT2 in Escherichia coli enhanced the bacterium's tolerance to heavy metals and ROS, consistent with its predicted role as an ROS scavenger. Taken together, our results, along with other relevant studies, suggest an important role of HbMTs in latex regeneration as well as species adaptation via the regulation of ROS homeostasis.
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Affiliation(s)
- Yacheng Huang
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan 570228, PR China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Yongjun Fang
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Xiangyu Long
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Linya Liu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan 570228, PR China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Jia Wang
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan 570228, PR China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Jinheng Zhu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan 570228, PR China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Yanyan Ma
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan 570228, PR China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Yunxia Qin
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Jiyan Qi
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
| | - Xinwen Hu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan 570228, PR China
| | - Chaorong Tang
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan 570228, PR China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, PR China
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Imam HT, Blindauer CA. Differential reactivity of closely related zinc(II)-binding metallothioneins from the plant Arabidopsis thaliana. J Biol Inorg Chem 2018; 23:137-154. [PMID: 29218630 PMCID: PMC5756572 DOI: 10.1007/s00775-017-1516-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 11/12/2017] [Indexed: 12/04/2022]
Abstract
The dynamics of metal binding to and transfer from metalloproteins involved in metal homeostasis are important for understanding cellular distribution of metal ions. The dicotyledonous plant Arabidopsis thaliana has two type 4 seed-specific metallothionein homologues, MT4a and MT4b, with likely roles in zinc(II) homeostasis. These two metallothioneins are 84% identical, with full conservation of all metal-binding cysteine and histidine residues. Yet, differences in their spatial and temporal expression patterns suggested divergence in their biological roles. To investigate whether biological functions are reflected in molecular properties, we compare aspects of zinc(II)-binding dynamics of full-length MT4a and MT4b, namely the pH dependence of zinc(II) binding and protein folding, and zinc(II) transfer to the chelator EDTA. UV-Vis and NMR spectroscopies as well as native electrospray ionisation mass spectrometry consistently showed that transfer from Zn6MT4a is considerably faster than from Zn6MT4b, with pseudo-first-order rate constants for the fastest observed step of k obs = 2.8 × 10-4 s-1 (MT4b) and k obs = 7.5 × 10-4 s-1 (MT4a) (5 µM protein, 500 µM EDTA, 25 mM Tris buffer, pH 7.33, 298 K). 2D heteronuclear NMR experiments allowed locating the most labile zinc(II) ions in domain II for both proteins. 3D homology models suggest that reactivity of this domain is governed by the local environment around the mononuclear Cys2His2 site that is unique to type 4 MTs. Non-conservative amino acid substitutions in this region affect local electrostatics as well as whole-domain dynamics, with both effects rendering zinc(II) ions bound to MT4a more reactive in metal transfer reactions. Therefore, domain II of MT4a is well suited to rapidly release its bound zinc(II) ions, in broad agreement with a previously suggested role of MT4a in zinc(II) transport and delivery to other proteins.
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Affiliation(s)
- Hasan T Imam
- Department of Chemistry, The University of Warwick, Coventry, CV4 7AL, UK
- School of Chemistry, University of St. Andrews, St. Andrews, KY16 9ST, UK
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Hasan MK, Cheng Y, Kanwar MK, Chu XY, Ahammed GJ, Qi ZY. Responses of Plant Proteins to Heavy Metal Stress-A Review. FRONTIERS IN PLANT SCIENCE 2017; 8:1492. [PMID: 28928754 PMCID: PMC5591867 DOI: 10.3389/fpls.2017.01492] [Citation(s) in RCA: 177] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/11/2017] [Indexed: 05/17/2023]
Abstract
Plants respond to environmental pollutants such as heavy metal(s) by triggering the expression of genes that encode proteins involved in stress response. Toxic metal ions profoundly affect the cellular protein homeostasis by interfering with the folding process and aggregation of nascent or non-native proteins leading to decreased cell viability. However, plants possess a range of ubiquitous cellular surveillance systems that enable them to efficiently detoxify heavy metals toward enhanced tolerance to metal stress. As proteins constitute the major workhorses of living cells, the chelation of metal ions in cytosol with phytochelatins and metallothioneins followed by compartmentalization of metals in the vacuoles as well as the repair of stress-damaged proteins or removal and degradation of proteins that fail to achieve their native conformations are critical for plant tolerance to heavy metal stress. In this review, we provide a broad overview of recent advances in cellular protein research with regards to heavy metal tolerance in plants. We also discuss how plants maintain functional and healthy proteomes for survival under such capricious surroundings.
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Affiliation(s)
- Md. Kamrul Hasan
- Department of Horticulture, Zhejiang UniversityHangzhou, China
- Department of Agricultural Chemistry, Sylhet Agricultural UniversitySylhet, Bangladesh
| | - Yuan Cheng
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Vegetables, Zhejiang Academy of Agricultural SciencesHangzhou, China
| | | | - Xian-Yao Chu
- Zhejiang Institute of Geological Survey, Geological Research Center for Agricultural Applications, China Geological SurveyBeijing, China
| | | | - Zhen-Yu Qi
- Agricultural Experiment Station, Zhejiang UniversityHangzhou, China
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Liu GD, Sheng Z, Hou CC, Ni J, Han YL, Wang YF, Zhou Y, Fu SY, Zhu JQ. Molecular cloning, characterization and expression analysis of metallothionein in the liver of the teleost Acrossocheilus fasciatus exposed to cadmium chloride. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2017; 53:1-9. [PMID: 28482255 DOI: 10.1016/j.etap.2017.03.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/26/2017] [Accepted: 03/28/2017] [Indexed: 06/07/2023]
Abstract
Metallothionein (MT) has a characteristic molecular structure with a cysteine-rich content. This unique structure provides metal-binding and redox capabilities and promoting metal homeostasis and detoxification in living animals. In order to evaluate the effects of cadmium (Cd) on hepatic MT expression in the liver of Acrossocheilus fasciatus, we obtained the complete cDNA of the A. fasciatus liver MT for the first time. The MT cDNA contains a 605-bp sequence, which codes for 60 amino acids. Protein alignment showed that the similarity between MT protein sequences of A. fasciatus and those of other vertebrates (especially teleosts) was very high and a cysteine residue structure was also conserved. MT was detected in the liver, kidney, gill, testis, muscle, spleen, heart and brain tissues of A. fasciatus by tissue-specific expression analysis. After Cd exposure, Cd/hemoglobin saturation assay, immunohistochemistry and reverse-transcription quantitative PCR (RT-qPCR) were used to describe MT expression in liver tissue. These techniques indicate a sensitive response by liver MT to Cd exposure. The results suggest that A. fasciatus MT may play an important role in the detoxification processes in the liver, and also would be a useful biomarker for monitoring metal pollution in aquatic environments. In addition, A. fasciatus could be regarded as one candidate for a model species for bony fishes in ecotoxicology.
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Affiliation(s)
- Guo-Di Liu
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Zhang Sheng
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Cong-Cong Hou
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Jie Ni
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Ying-Li Han
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - You-Fa Wang
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Yang Zhou
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Su-Yan Fu
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Jun-Quan Zhu
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, PR China.
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Ruta LL, Lin YF, Kissen R, Nicolau I, Neagoe AD, Ghenea S, Bones AM, Farcasanu IC. Anchoring plant metallothioneins to the inner face of the plasma membrane of Saccharomyces cerevisiae cells leads to heavy metal accumulation. PLoS One 2017; 12:e0178393. [PMID: 28562640 PMCID: PMC5451056 DOI: 10.1371/journal.pone.0178393] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 05/14/2017] [Indexed: 11/18/2022] Open
Abstract
In this study we engineered yeast cells armed for heavy metal accumulation by targeting plant metallothioneins to the inner face of the yeast plasma membrane. Metallothioneins (MTs) are cysteine-rich proteins involved in the buffering of excess metal ions, especially Cu(I), Zn(II) or Cd(II). The cDNAs of seven Arabidopsis thaliana MTs (AtMT1a, AtMT1c, AtMT2a, AtMT2b, AtMT3, AtMT4a and AtMT4b) and four Noccaea caerulescens MTs (NcMT1, NcMT2a, NcMT2b and NcMT3) were each translationally fused to the C-terminus of a myristoylation green fluorescent protein variant (myrGFP) and expressed in Saccharomyces cerevisiae cells. The myrGFP cassette introduced a yeast myristoylation sequence which allowed directional targeting to the cytosolic face of the plasma membrane along with direct monitoring of the intracellular localization of the recombinant protein by fluorescence microscopy. The yeast strains expressing plant MTs were investigated against an array of heavy metals in order to identify strains which exhibit the (hyper)accumulation phenotype without developing toxicity symptoms. Among the transgenic strains which could accumulate Cu(II), Zn(II) or Cd(II), but also non-canonical metal ions, such as Co(II), Mn(II) or Ni(II), myrGFP-NcMT3 qualified as the best candidate for bioremediation applications, thanks to the robust growth accompanied by significant accumulative capacity.
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Affiliation(s)
| | - Ya-Fen Lin
- Cell, Molecular Biology and Genomics Group, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ralph Kissen
- Cell, Molecular Biology and Genomics Group, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ioana Nicolau
- Faculty of Chemistry, University of Bucharest, Bucharest, Romania
| | | | - Simona Ghenea
- Institute of Biochemistry of the Romanian Academy, Bucharest, Romania
| | - Atle M. Bones
- Cell, Molecular Biology and Genomics Group, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
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Irvine GW, Stillman MJ. Residue Modification and Mass Spectrometry for the Investigation of Structural and Metalation Properties of Metallothionein and Cysteine-Rich Proteins. Int J Mol Sci 2017; 18:ijms18050913. [PMID: 28445428 PMCID: PMC5454826 DOI: 10.3390/ijms18050913] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 04/18/2017] [Accepted: 04/20/2017] [Indexed: 12/23/2022] Open
Abstract
Structural information regarding metallothioneins (MTs) has been hard to come by due to its highly dynamic nature in the absence of metal-thiolate cluster formation and crystallization difficulties. Thus, typical spectroscopic methods for structural determination are limited in their usefulness when applied to MTs. Mass spectrometric methods have revolutionized our understanding of protein dynamics, structure, and folding. Recently, advances have been made in residue modification mass spectrometry in order to probe the hard-to-characterize structure of apo- and partially metalated MTs. By using different cysteine specific alkylation reagents, time dependent electrospray ionization mass spectrometry (ESI-MS), and step-wise “snapshot” ESI-MS, we are beginning to understand the dynamics of the conformers of apo-MT and related species. In this review we highlight recent papers that use these and similar techniques for structure elucidation and attempt to explain in a concise manner the data interpretations of these complex methods. We expect increasing resolution in our picture of the structural conformations of metal-free MTs as these techniques are more widely adopted and combined with other promising tools for structural elucidation.
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Affiliation(s)
- Gordon W Irvine
- Department of Chemistry, The University of Western Ontario, London, ON N6A 3K7, Canada.
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, London, ON N6A 3K7, Canada.
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Li LS, Meng YP, Cao QF, Yang YZ, Wang F, Jia HS, Wu SB, Liu XG. Type 1 Metallothionein (ZjMT) Is Responsible for Heavy Metal Tolerance in Ziziphus jujuba. BIOCHEMISTRY (MOSCOW) 2016; 81:565-73. [PMID: 27301284 DOI: 10.1134/s000629791606002x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Metallothioneins (MTs) are a family of low molecular weight, cysteine-rich, metal-binding proteins that are able to make cells to uptake heavy metals from the environment. Molecular and functional characterization of this gene family improves understanding of the mechanisms underlying heavy metal tolerance in higher organisms. In this study, a cDNA clone, encoding 74-a.a. metallothionein type 1 protein (ZjMT), was isolated from the cDNA library of Ziziphus jujuba. At the N- and C-terminals of the deduced amino acid sequence of ZjMT, six cysteine residues were arranged in a CXCXXXCXCXXXCXC and CXCXXXCXCXXCXC structure, respectively, indicating that ZjMT is a type 1 MT. Quantitative PCR analysis of plants subjected to cadmium stress showed enhanced expression of ZjMT gene in Z. jujuba within 24 h upon Cd exposure. Escherichia coli cells expressing ZjMT exhibited enhanced metal tolerance and higher accumulation of metal ions compared with control cells. The results indicate that ZjMT contributes to the detoxification of metal ions and provides marked tolerance against metal stresses. Therefore, ZjMT may be a potential candidate for tolerance enhancement in vulnerable plants to heavy metal stress and E. coli cells containing the ZjMT gene may be applied to adsorb heavy metals in polluted wastewater.
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Affiliation(s)
- Lan-Song Li
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, 030024 Taiyuan, China.
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