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Konieczna W, Turkan S, Warchoł M, Skrzypek E, Dąbrowska GB, Mierek-Adamska A. The Contribution of Trichoderma viride and Metallothioneins in Enhancing the Seed Quality of Avena sativa L. in Cd-Contaminated Soil. Foods 2024; 13:2469. [PMID: 39123659 PMCID: PMC11312241 DOI: 10.3390/foods13152469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Revised: 07/28/2024] [Accepted: 08/01/2024] [Indexed: 08/12/2024] Open
Abstract
Pollution of arable land with heavy metals is a worldwide problem. Cadmium (Cd) is a toxic metal that poses a severe threat to humans' and animals' health and lives. Plants can easily absorb Cd from the soil, and plant-based food is the main means of exposure to this hazardous element for humans and animals. Phytoremediation is a promising plant-based approach to removing heavy metals from the soil, and plant growth-promoting micro-organisms such as the fungi Trichoderma can enhance the ability of plants to accumulate metals. Inoculation of Avena sativa L. (oat) with Trichoderma viride enhances germination and seedling growth in the presence of Cd and, in this study, the growth of 6-month-old oat plants in Cd-contaminated soil was not increased by inoculation with T. viride, but a 1.7-fold increase in yield was observed. The content of Cd in oat shoots depended on the Cd content in the soil. Still, it was unaffected by the inoculation with T. viride. A. sativa metallothioneins (AsMTs) participate in plant-fungi interaction, however, their role in this study depended on MT type and Cd concentration. The inoculation of A. sativa with T. viride could be a promising approach to obtaining a high yield in Cd-contaminated soil without increasing the Cd content in the plant.
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Affiliation(s)
- Wiktoria Konieczna
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (S.T.); (G.B.D.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| | - Sena Turkan
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (S.T.); (G.B.D.)
| | - Marzena Warchoł
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (M.W.); (E.S.)
| | - Edyta Skrzypek
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (M.W.); (E.S.)
| | - Grażyna B. Dąbrowska
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (S.T.); (G.B.D.)
| | - Agnieszka Mierek-Adamska
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (S.T.); (G.B.D.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
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Łuczkowski M, Leszczyńska W, Wątły J, Clemens S, Krężel A. Phytochelatins Bind Zn(II) with Micro- to Picomolar Affinities without the Formation of Binuclear Complexes, Exhibiting Zinc Buffering and Muffling Rather than Storing Functions. Inorg Chem 2024; 63:10915-10931. [PMID: 38845098 PMCID: PMC11191002 DOI: 10.1021/acs.inorgchem.4c01707] [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: 04/26/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/18/2024]
Abstract
Phytochelatins (PCs) are poly-Cys peptides containing a repeating γ-Glu-Cys motif synthesized in plants, algae, certain fungi, and worms by PC synthase from reduced glutathione. It has been shown that an excess of toxic metal ions induces their biosynthesis and that they are responsible for the detoxification process. Little is known about their participation in essential metal binding under nontoxic, basal conditions under which PC synthase is active. This study presents spectroscopic and thermodynamic interactions with the PC2-PC5 series, mainly focusing on the relations between Zn(II) complex stability and cellular Zn(II) availability. The investigations employed mass spectrometry, UV-vis spectroscopy, potentiometry, competition assays with zinc probes, and isothermal titration calorimetry (ITC). All peptides form ZnL complexes, while ZnL2 was found only for PC2, containing two to four sulfur donors in the coordination sphere. Binuclear species typical of Cd(II)-PC complexes are not formed in the case of Zn(II). Results demonstrate that the affinity for Zn(II) increases linearly from PC2 to PC4, ranging from micro- to low-picomolar. Further elongation does not significantly increase the stability. Stability elevation is driven mainly by entropic factors related to the chelate effect and conformational restriction rather than enthalpic factors related to the increasing number of sulfur donors. The affinity of the investigated PCs falls within the range of exchangeable Zn(II) concentrations (hundreds of pM) observed in plants, supporting for the first time a role of PCs both in buffering and in muffling cytosolic Zn(II) concentrations under normal conditions, not exposed to zinc excess, where short PCs have been identified in numerous studies. Furthermore, we found that Cd(II)-PC complexes demonstrate significantly higher metal capacities due to the formation of polynuclear species, which are lacking for Zn(II), supporting the role of PCs in Cd(II) storage (detoxification) and Zn(II) buffering and muffling. Our results on phytochelatins' coordination chemistry and thermodynamics are important for zinc biology and understanding the molecular basis of cadmium toxicity, leaving room for future studies.
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Affiliation(s)
- Marek Łuczkowski
- Department
of Chemical Biology, Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14a, 50-383 Wrocław, Poland
| | - Weronika Leszczyńska
- Department
of Chemical Biology, Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14a, 50-383 Wrocław, Poland
| | - Joanna Wątły
- Department
of Chemical Biology, Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14a, 50-383 Wrocław, Poland
| | - Stephan Clemens
- Department
of Plant Physiology, Faculty of Biology, Chemistry and Earth Sciences, University of Bayreuth, 95440 Bayreuth, Germany
| | - Artur Krężel
- Department
of Chemical Biology, Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14a, 50-383 Wrocław, Poland
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Konieczna W, Mierek-Adamska A, Chojnacka N, Antoszewski M, Szydłowska-Czerniak A, Dąbrowska GB. Characterization of the Metallothionein Gene Family in Avena sativa L. and the Gene Expression during Seed Germination and Heavy Metal Stress. Antioxidants (Basel) 2023; 12:1865. [PMID: 37891944 PMCID: PMC10603854 DOI: 10.3390/antiox12101865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Metallothioneins (MTs) are a family of small proteins rich in cysteine residues. The sulfhydryl group of metallothioneins can bind to metal ions, maintaining metal homeostasis and protecting the cells from damage caused by toxic heavy metals. Moreover, MTs can function as reactive oxygen species scavengers since cysteine thiols undergo reversible and irreversible oxidation. Here, we identified 21 metallothionein genes (AsMTs) in the oat (Avena sativa L.) genome, which were divided into four types depending on the amino acid sequences of putative proteins encoded by identified genes. Analysis of promoter sequences showed that MTs might respond to a variety of stimuli, including biotic and abiotic stresses and phytohormones. The results of qRT-PCR showed that all four types of AsMTs are differentially expressed during the first 48 hours of seed germination. Moreover, stress induced by the application of zinc, cadmium, and a mixture of zinc and cadmium affects the expression of oat MTs variously depending on the MT type, indicating that AsMT1-4 fulfil different roles in plant cells.
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Affiliation(s)
- Wiktoria Konieczna
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (M.A.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| | - Agnieszka Mierek-Adamska
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (M.A.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| | - Natalia Chojnacka
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (M.A.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| | - Marcel Antoszewski
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (M.A.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland
| | - Aleksandra Szydłowska-Czerniak
- Department of Analytical Chemistry and Applied Spectroscopy, Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland;
| | - Grażyna B. Dąbrowska
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; (W.K.); (M.A.)
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Gautam N, Tiwari M, Kidwai M, Dutta P, Chakrabarty D. Functional characterization of rice metallothionein OsMT-I-Id: Insights into metal binding and heavy metal tolerance mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:131815. [DOI: https:/doi.org/10.1016/j.jhazmat.2023.131815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
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Gautam N, Tiwari M, Kidwai M, Dutta P, Chakrabarty D. Functional characterization of rice metallothionein OsMT-I-Id: Insights into metal binding and heavy metal tolerance mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:131815. [PMID: 37336105 DOI: 10.1016/j.jhazmat.2023.131815] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 06/07/2023] [Accepted: 06/07/2023] [Indexed: 06/21/2023]
Abstract
Metallothioneins (MTs) are cysteine-rich proteins known for their strong metal-binding capabilities, making them effective in detoxifying heavy metals (HMs). This study focuses on characterizing the functional properties of OsMT-I-Id, a type-I Metallothionein found in rice. Using a HM-responsive yeast cup1Δ (DTY4), ycf1∆ (for cadmium), and acr3∆ mutants (for trivalent arsenic), we assessed the impact of OsMT-I-Id on metal accumulation and cellular resilience. Our results demonstrated that yeast cells expressing OsMT-I-Id showed increased tolerance and accumulated higher levels of copper (Cu), arsenic (As), and cadmium (Cd), compared to control cells. This can be attributed to the protein's ability to chelate and bind HMs. Site-directed mutagenesis was employed to investigate the specific contributions of cysteine residues. The study revealed that yeast cells with a mutated C-domain displayed heightened HM sensitivity, while cells with a mutated N-domain exhibited reduced sensitivity. This underscores the critical role of C-cysteine-rich domains in metal binding and tolerance of type-I rice MTs. Furthermore, the study identified the significance of the 12th cysteine position at the N-domain and the 68th and 72nd cysteine positions at the C-domain in influencing OsMT-I-Id metal-binding capacity. This research provides novel insights into the structure-function relationship and metal binding properties of type-I plant MTs.
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Affiliation(s)
- Neelam Gautam
- Biotechnology and Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Madhu Tiwari
- Biotechnology and Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow 226001, India
| | - Maria Kidwai
- Biotechnology and Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow 226001, India
| | - Prasanna Dutta
- Biotechnology and Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Debasis Chakrabarty
- Biotechnology and Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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Konieczna W, Warchoł M, Mierek-Adamska A, Skrzypek E, Waligórski P, Piernik A, Dąbrowska GB. Changes in physio-biochemical parameters and expression of metallothioneins in Avena sativa L. in response to drought. Sci Rep 2023; 13:2486. [PMID: 36775830 PMCID: PMC9922688 DOI: 10.1038/s41598-023-29394-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 02/03/2023] [Indexed: 02/13/2023] Open
Abstract
Drought is one of the major threats to food security. Among several mechanisms involved in plant stress tolerance, one protein family-the plant metallothioneins (MTs)-shows great promise for enhancing drought resistance. Plant metallothioneins in oat (Avena sativa L.) have not yet been deeply analysed, and the literature lacks a comprehensive study of the whole family of plant MTs in response to drought. In this study, we showed that the number and nature of cis-elements linked with stress response in promoters of AsMTs1-3 differed depending on the MT type. Drought stress in oat plants caused an increase in the expression of AsMT2 and AsMT3 and a decrease in the expression of AsMT1 compared to well-watered plants. Moreover, the low values of relative water content, water use efficiency, net photosynthesis (PN), transpiration (E), stomatal conductance (gs), chlorophyll a, and carotenoid were accompanied by high levels of electrolyte leakage, internal CO2 concentration (Ci) and abscisic acid content, and high activity of antioxidants enzymes in plants under drought stress. The present study puts forward the idea that AsMTs are crucial for oat response to drought stress not only by regulating antioxidant activity but also by changing the plant water regime and photosynthesis. Our results support the hypothesis that structural differences among types of plant MTs reflect their diversified physiological roles.
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Affiliation(s)
- Wiktoria Konieczna
- Department of Genetics, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100, Toruń, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100, Toruń, Poland
| | - Marzena Warchoł
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Agnieszka Mierek-Adamska
- Department of Genetics, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100, Toruń, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100, Toruń, Poland
| | - Edyta Skrzypek
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Piotr Waligórski
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Agnieszka Piernik
- Department of Geobotany and Landscape Planning, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100, Toruń, Poland
| | - Grażyna B Dąbrowska
- Department of Genetics, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100, Toruń, Poland.
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Pourjalali Z, Shahpiri A, Golkar P. Barley metallothionein isoforms, MT2b2 and MT4, differentially respond to photohormones in barley aleurone layer and their recombinant forms show different affinity for binding to zinc and cadmium. Biometals 2023; 36:3-18. [PMID: 36309886 DOI: 10.1007/s10534-022-00452-y] [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: 07/02/2022] [Accepted: 09/25/2022] [Indexed: 11/25/2022]
Abstract
Metallothioneins (MTs) are metal-binding proteins that have important roles in the homeostasis of heavy metals. In this study, the two MT genes was studied in response to phytohormones using the barley aleurone layer as a kind of model system. The aleurone layer was isolated from barley embryo-less half grains and was incubated for 24 h with different phytohormones. Based on the results the genes encoding HvMT2b2 and HvMT4 were down-regulated through gibberellic acid (GA), while they were and up-regulated through salicylic acid (SA). Despite this, these two genes were differentially expressed to other hormones. Furthermore, the proteins HvMT2b2 and HvMT4 were heterologous expressed as GST-fusion proteins in E. coli. The HvMT4 and HvMT2b2 heterologous expression in E. coli gives rise to 10- and 3-fold improvements in the accumulation capacity for Zn2+, respectively. Whereas the transgenic E. coli strain that expresses HvMT2b2 could accumulate Cd2+ three-fold higher than control. The expression of HvMT4 did not affect the accumulation of Cd2+. HvMT4 which is known as seed-specific isoform seems to be able to bind to Zn2+ with good affinity and cannot bind Cd2+. In comparison, HvMT2b2 was able to bind both Zn2+ and Cd2+. Therefore HvMT4 could serve a noteworthy role in zinc storage in barley seeds. The expression of HvMT4 is induced by SA 30-fold, concerning the untreated aleurone layer. Such results could provide good insights for the assessment of the effects of phytohormones in the molecular mechanism involved in essential metal storage in cereal seeds.
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Affiliation(s)
- Zahra Pourjalali
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Azar Shahpiri
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
| | - Pooran Golkar
- Department of Natural Resources, Isfahan University of Technology, Isfahan, 84156-83111, Iran
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Zhao J, Xie R, Lin J, Xu L, Gao X, Lin X, Tian S, Lu L. SaMT3 in Sedum alfredii drives Cd detoxification by chelation and ROS-scavenging via Cys residues. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 315:120410. [PMID: 36240968 DOI: 10.1016/j.envpol.2022.120410] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
Metallothioneins (MTs), a group of cysteine-rich proteins, are effective chelators of cadmium (Cd) and play a key role in plant Cd detoxification. However, little is known about the role of single cysteine (Cys) residues in the MTs involved in the adaptation of plants to Cd stress, especially, in hyperaccumulators. In the present study, we functionally characterised SaMT3 in S. alfredii, a Cd/Zn hyperaccumulator native to China. Our results showed that the C- and N- terminal regions of SaMT3 had differential functional natures in S. alfredii and determined its Cd hypertolerance and detoxification. Two CXC motifs within the C-terminal region were revealed to play a crucial role in Cd sensing and binding, whereas the four Cys-residues within the N-terminal region were involved in scavenging reactive oxygen species (ROS). An S. alfredii transgenic system based on callus transformation was developed to further investigate the in-planta gene function. The SaMT3-overexpressing transgenic plant roots were more tolerant to Cd than those of wild-type plants. Knockout of SaMT3 resulted in significantly decreased Cd concentrations and increased ROS levels after exposure to Cd stress. We demonstrated the SaMT3-mediated adaptation strategy in S. alfredii, which uses metal chelation and ROS scavenging in response to Cd stress. Our results further reveal the molecular mechanisms underlying Cd detoxification in hyperaccumulating plants, as well as the relation between Cys-related motifs and the metal binding properties of MTs. This research provides valuable insights into the functions of SaMT3 in S. alfredii, and improves our understanding of Cd hyperaccumulation in plants.
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Affiliation(s)
- Jianqi Zhao
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058, China.
| | - Ruohan Xie
- School of Agriculture, Sun Yat-Sen University, Guangzhou, 510275, China.
| | - Jiayu Lin
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058, China.
| | - Lingling Xu
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058, China.
| | - Xiaoyu Gao
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China; College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
| | - Xianyong Lin
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058, China.
| | - Shengke Tian
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058, China.
| | - Lingli Lu
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058, China.
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Chorianopoulou SN, Bouranis DL. The Role of Sulfur in Agronomic Biofortification with Essential Micronutrients. PLANTS 2022; 11:plants11151979. [PMID: 35956455 PMCID: PMC9370111 DOI: 10.3390/plants11151979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/22/2022] [Accepted: 07/23/2022] [Indexed: 11/16/2022]
Abstract
Sulfur (S) is an essential macronutrient for plants, being necessary for their growth and metabolism and exhibiting diverse roles throughout their life cycles. Inside the plant body, S is present either in one of its inorganic forms or incorporated in an organic compound. Moreover, organic S compounds may contain S in its reduced or oxidized form. Among others, S plays roles in maintaining the homeostasis of essential micronutrients, e.g., iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn). One of the most well-known connections is homeostasis between S and Fe, mainly in terms of the role of S in uptake, transportation, and distribution of Fe, as well as the functional interactions of S with Fe in the Fe-S clusters. This review reports the available information describing the connections between the homeostasis of S and Fe, Cu, Zn, and Mn in plants. The roles of S- or sulfur-derived organic ligands in metal uptake and translocation within the plant are highlighted. Moreover, the roles of these micronutrients in S homeostasis are also discussed.
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Liu S, Liu Y, Liu C, Li Y, Zhang F, Ma H. Isolation and Characterization of the GmMT-II Gene and Its Role in Response to High Temperature and Humidity Stress in Glycine max. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11111503. [PMID: 35684276 PMCID: PMC9182806 DOI: 10.3390/plants11111503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 05/27/2023]
Abstract
Metallothioneins (MTs) are polypeptide-encoded genes involved in plant growth, development, seed formation, and diverse stress response. High temperature and humidity stress (HTH) reduce seed development and maturity of the field-grown soybean, which also leads to seed pre-harvest deterioration. However, the function of MTs in higher plants is still largely unknown. Herein, we isolated and characterized the soybean metallothionein II gene. The full-length fragment is 255 bp and encodes 85 amino acids and contains the HD domain and the N-terminal non-conservative region. The subcellular location of the GmMT-II-GFP fusion protein was clearly located in the nucleus, cytoplasm, and cell membrane. The highest expression of the GmMT-II gene was observed in seeds both of the soybean Xiangdou No. 3 and Ningzhen No. 1 cultivars, as compared to other plant tissues. Similarly, gene expression was higher 45 days after flowering followed by 30, 40, and 35 days. Furthermore, the GmMT-II transcript levels were significantly higher at 96 and 12 h in the cultivars Xiangdou No. 3 and Ningzhen No. 1 under HTH stress, respectively. In addition, it was found that when the Gm1-MMP protein was deleted, the GmMT-II could bind to the propeptide region of the Gm1-MMP, but not to the signal peptide region or the catalytic region. GmMT-II overexpression in transgenic Arabidopsis increased seed germination and germination rate under HTH conditions, conferring enhanced resistance to HTH stress. GmMT-II overexpressing plants suffered less oxidative damage under HTH stress, as reflected by lower MDA and H2O2 content and ROS production than WT plants. In addition, the activity of antioxidant enzymes namely SOD, CAT, and POD was significantly higher in all transgenic Arabidopsis lines under HTH stress compared wild-tpye plants. Our results suggested that GmMT-II is related to growth and development and confers enhanced HTH stress tolerance in plants by reduction of oxidative molecules through activation of antioxidant activities. These findings will be helpful for us in further understanding of the biological functions of MT-II in plants.
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Affiliation(s)
- Sushuang Liu
- Department of Life Sciences and Health, Huzhou College, Huzhou 313000, China; (S.L.); (C.L.)
| | - Yanmin Liu
- Department of Life Sciences and Health, Huzhou College, Huzhou 313000, China; (S.L.); (C.L.)
| | - Chundong Liu
- Department of Life Sciences and Health, Huzhou College, Huzhou 313000, China; (S.L.); (C.L.)
| | - Yang Li
- College of Life Science, Huzhou University, Huzhou 313000, China;
| | - Feixue Zhang
- Institute of Crop, Huzhou Academy of Agricultural Sciences, Huzhou 313000, China;
| | - Hao Ma
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
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Rono JK, Sun D, Yang ZM. Metallochaperones: A critical regulator of metal homeostasis and beyond. Gene 2022; 822:146352. [PMID: 35183685 DOI: 10.1016/j.gene.2022.146352] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/03/2022] [Accepted: 02/15/2022] [Indexed: 12/11/2022]
Abstract
Metallochaperones are a class of unique protein families that was originally found to interact with cellular metal ions by metal delivery to specific target proteins such as metal enzymes. Recently, some members of metallochaperones receive much attention owning to their multi-biological functions in mediating plant growth, development and biotic or abiotic stress responses, particularly in the aspects of metal transport and accumulation in plants. For example, some non-essential toxic heavy metals (e.g. cadmium and mercury) accumulating in farmland due to the industrial and agronomic activities, are a constant threat to crop production, food safety and human health. Digging genetic resources and functional genes like metallochaperones is critical for understanding the metal detoxification in plants, and may help develop cleaner crops with minimal toxic metals in leafy vegetables and grains, or plants for metal-polluted soil phytoremediation. In this review, we highlight the current advancement of the research on functions of metallochaperones in metal accumulation, detoxification and homeostasis. We also summarize the recent progress of the research on the critical roles of the metal-binding proteins in regulating plant responses to some other biological processes including plant growth, development, pathogen stresses, and abiotic stresses such salt, drought, cold and light. Finally, an additional capacity of some members of metallochaperones involved in the resistance to the pathogen attack and possibly regulatory roles was reviewed.
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Affiliation(s)
- Justice Kipkorir Rono
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Di Sun
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhi Min Yang
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
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12
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Metalloprotein-Specific or Critical Amino Acid Residues: Perspectives on Plant-Precise Detoxification and Recognition Mechanisms under Cadmium Stress. Int J Mol Sci 2022; 23:ijms23031734. [PMID: 35163656 PMCID: PMC8836122 DOI: 10.3390/ijms23031734] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 12/15/2022] Open
Abstract
Cadmium (Cd) pollution in cultivated land is caused by irresistible geological factors and human activities; intense diffusion and migration have seriously affected the safety of food crops. Plants have evolved mechanisms to control excessive influx of Cd in the environment, such as directional transport, chelation and detoxification. This is done by some specific metalloproteins, whose key amino acid motifs have been investigated by scientists one by one. The application of powerful cell biology, crystal structure science, and molecular probe targeted labeling technology has identified a series of protein families involved in the influx, transport and detoxification of the heavy metal Cd. This review summarizes them as influx proteins (NRAMP, ZIP), chelating proteins (MT, PDF), vacuolar proteins (CAX, ABCC, MTP), long-distance transport proteins (OPT, HMA) and efflux proteins (PCR, ABCG). We selected representative proteins from each family, and compared their amino acid sequence, motif structure, subcellular location, tissue specific distribution and other characteristics of differences and common points, so as to summarize the key residues of the Cd binding target. Then, we explain its special mechanism of action from the molecular structure. In conclusion, this review is expected to provide a reference for the exploration of key amino acid targets of Cd, and lay a foundation for the intelligent design and breeding of crops with high/low Cd accumulation.
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13
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Zou T, Pu L, Lin R, Mo H, Wang Z, Jian S, Zhang M. Roles of Canavalia rosea metallothioneins in metal tolerance and extreme environmental adaptation to tropical coral reefs. JOURNAL OF PLANT PHYSIOLOGY 2022; 268:153559. [PMID: 34839100 DOI: 10.1016/j.jplph.2021.153559] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 11/08/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Canavalia rosea (Sw.) DC is a perennial twining herb distributed in the semi-arid and saline-alkali areas of coastal regions and has evolved halotolerance. In this study, we present the first comprehensive survey of the metallothionein (MT) gene family in C. rosea. MT proteins belong to a family of low-molecular-weight polypeptides with a high content of cysteine residues, which have an affinity to bind with heavy metal ions. MTs also play important roles in stress responses as reactive oxygen species (ROS) scavengers. A total of six CrMTs were identified in the C. rosea genome and classified into four subgroups by phylogenetic analysis. An analysis of the cis-acting elements revealed that a series of hormone-, stress-, and development-related cis-acting elements were present in the promoter regions of CrMTs. The expression of CrMTs also showed habitat- and environmental stress-regulated patterns in C. rosea. CrMT overexpression in yeast enhanced tolerance to heavy metals and ROS, as well as high osmotic and alkalinity stress, which is consistent with their predicted roles as metal-chelating proteins and ROS scavengers. Our results indicate that the CrMT genes might contribute to the detoxification of plants to metals and provide marked tolerance against abiotic stress. The expression patterns of CrMTs in C. rosea also indicate that CrMTs play important roles in this species' response to extreme environments on tropical islands and reefs, probably by improving the thermotolerance of C. rosea plants.
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Affiliation(s)
- Tao Zou
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650, China; University of the Chinese Academy of Sciences, Beijing, 100039, China
| | - Lin Pu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; University of the Chinese Academy of Sciences, Beijing, 100039, China; CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Ruoyi Lin
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; University of the Chinese Academy of Sciences, Beijing, 100039, China; CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Hui Mo
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650, China; CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Zhengfeng Wang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
| | - Shuguang Jian
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Mei Zhang
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650, China.
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14
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Feng SJ, Liu XS, Cao HW, Yang ZM. Identification of a rice metallochaperone for cadmium tolerance by an epigenetic mechanism and potential use for clean up in wetland. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117837. [PMID: 34329044 DOI: 10.1016/j.envpol.2021.117837] [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: 03/17/2021] [Revised: 07/09/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Cadmium (Cd) is a toxic heavy metal that initiates diverse chronic diseases through food chains. Developing a biotechnology for manipulating Cd uptake in plants is beneficial to reduce environmental and health risks. Here, we identified a novel epigenetic mechanism underlying Cd accumulation regulated by an uncharacterized metallochaperone namely Heavy Metal Responsive Protein (HMP) in rice plants. OsHMP resides in cytoplasm and nucleus, dominantly induced by Cd stress and binds directly to Cd ions. OsHMP overexpression enhanced the rice growth under Cd stress but accumulated more Cd, whereas knockout or knockdown of OsHMP showed a contrasting effect. The enhanced Cd accumulation in the transgenic lines was confirmed by a long-term experiment with rice growing at the environmentally realistic Cd concentration in soil. The bisulfite sequencing and chromatin immunoprecipitation assessments revealed that Cd stress reduced significantly the DNA methylation at CpG (Cytosine-Guanine) and histone H3K9me2 marks in the upstream of OsHMP. By identifying a couple of mutants defective in DNA methylation and histone modification (H3K9me2) such as Osmet1 (methylatransfease1) and Ossdg714 (kryptonite), we found that the Cd-induced epigenetic hypomethylation at the region was associated with OsHMP overexpression, which consequently led to Cd detoxification in rice. The causal relationship was confirmed by the GUS reporter gene coupled with OsHMP and OsMET1 whereby OsMET1 repressed directly the OsHMP expression. Our work signifies that expression of OsHMP is required for Cd detoxification in rice plants, and the Cd-induced hypomethylation in the specific region is responsible for the enhanced OsHMP expression. In summary, this study gained an insight into the epigenetic mechanism for additional OsHMP expression which consequently ensures rice adaptation to the Cd-contaminated environment.
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Affiliation(s)
- Sheng Jun Feng
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China; The State Key Laboratory of Subtropical Silviculture, Laboratory of Plant Molecular and Developmental Biology, Zhejiang A&F University, Hangzhou, 311300, China
| | - Xue Song Liu
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hong Wei Cao
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhi Min Yang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China.
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15
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Abdin AY, Jacob C, Kästner L. The Enigmatic Metallothioneins: A Case of Upward-Looking Research. Int J Mol Sci 2021; 22:5984. [PMID: 34206018 PMCID: PMC8198881 DOI: 10.3390/ijms22115984] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/05/2021] [Accepted: 05/26/2021] [Indexed: 11/17/2022] Open
Abstract
In the mid-1950s, Bert Lester Vallee and his colleague Marvin Margoshes discovered a molecule referred to today as metallothionein (MT). Meanwhile, MTs have been shown to be common in many biological organisms. Despite their prevalence, however, it remains unclear to date what exactly MTs do and how they contribute to the biological function of an organism or organ. We investigate why biochemical research has not yet been able to pinpoint the function(s) of MTs. We shall systematically examine both the discovery of and recent research on Dr. Vallee's beloved family of MT proteins utilizing tools from philosophy of science. Our analysis highlights that Vallee's initial work exhibited features prototypical of a developing research tradition: it was upward-looking, exploratory, and utilized mere interactions. Since the 1960s, MT research has increasingly become intervention- and hypothesis-based while it remained largely upward-looking in character. Whilst there is no reason to think that upward-looking research cannot successfully yield structure-function mappings, it has not yet been successful in the case of MTs. Thus, we suggest it might be time to change track and consider other research strategies looking into the evolution of MTs. Recent studies in mollusks render research in this direction worthy of pursuit.
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Affiliation(s)
- Ahmad Yaman Abdin
- Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, D-66123 Saarbruecken, Germany; (A.Y.A.); (C.J.)
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181–UCCS–Unité de Catalyse et Chimie du Solide, F-59000 Lille, France
| | - Claus Jacob
- Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, D-66123 Saarbruecken, Germany; (A.Y.A.); (C.J.)
| | - Lena Kästner
- Institute of Philosophy, Saarland University, D-66123 Saarbruecken, Germany
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16
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Nobahar A, Carlier JD, Miguel MG, Costa MC. A review of plant metabolites with metal interaction capacity: a green approach for industrial applications. Biometals 2021; 34:761-793. [PMID: 33961184 DOI: 10.1007/s10534-021-00315-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/28/2021] [Indexed: 01/20/2023]
Abstract
Rapid industrial development is responsible for severe problems related to environmental pollution. Many human and industrial activities require different metals and, as a result, great amounts of metals/heavy metals are discharged into the water and soil making them dangerous for both human and ecosystems and this is being aggravated by intensive demand and utilization. In addition, compounds with metal binding capacities are needed to be used for several purposes including in activities related to the removal and/or recovery of metals from effluents and soils, as metals' corrosion inhibitors, in the synthesis of metallic nanoparticles and as metal related pharmaceuticals, preferably a with minimum risks associated to the environment. Plants are able to synthesize an uncountable number of compounds with numerous functions, including compounds with metal binding capabilities. In fact, some of the plants' secondary metabolites can bind to various metals through different mechanisms, as such they are excellent sources of such compounds due to their high availability and vast diversity. In addition, the use of plant-based compounds is desirable from an environmental and economical point of view, thus being potential candidates for utilization in different industrial activities, replacing conventional physiochemical methods. This review focuses on the ability of some classes of compounds that can be found in relatively high concentrations in plants, having good metal binding capacities and thus with potential utilization in metal based industrial activities and that can be involved in the progressive development of new environmentally friendly strategies.
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Affiliation(s)
- Amir Nobahar
- Centre of Marine Sciences (CCMAR), University of the Algarve, Gambelas Campus, 8005-139, Faro, Portugal.,Faculty of Sciences and Technology, University of the Algarve, Gambelas Campus, 8005-139, Faro, Portugal
| | - Jorge Dias Carlier
- Centre of Marine Sciences (CCMAR), University of the Algarve, Gambelas Campus, 8005-139, Faro, Portugal
| | - Maria Graça Miguel
- Faculty of Sciences and Technology, University of the Algarve, Gambelas Campus, 8005-139, Faro, Portugal
| | - Maria Clara Costa
- Centre of Marine Sciences (CCMAR), University of the Algarve, Gambelas Campus, 8005-139, Faro, Portugal. .,Faculty of Sciences and Technology, University of the Algarve, Gambelas Campus, 8005-139, Faro, Portugal.
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17
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Bellini E, Betti C, Sanità di Toppi L. Responses to Cadmium in Early-Diverging Streptophytes (Charophytes and Bryophytes): Current Views and Potential Applications. PLANTS (BASEL, SWITZERLAND) 2021; 10:770. [PMID: 33919852 PMCID: PMC8070800 DOI: 10.3390/plants10040770] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 11/16/2022]
Abstract
Several transition metals are essential for plant growth and development, as they are involved in various fundamental metabolic functions. By contrast, cadmium (Cd) is a metal that can prove extremely toxic for plants and other organisms in a dose-dependent manner. Charophytes and bryophytes are early-diverging streptophytes widely employed for biomonitoring purposes, as they are able to cope with high concentrations of toxic metal(loid)s without showing any apparent heavy damage. In this review, we will deal with different mechanisms that charophytes and bryophytes have evolved to respond to Cd at a cellular level. Particular attention will be addressed to strategies involving Cd vacuolar sequestration and cell wall immobilization, focusing on specific mechanisms that help achieve detoxification. Understanding the effects of metal(loid) pollution and accumulation on the morpho-physiological traits of charophytes and bryophytes can be in fact fundamental for optimizing their use as phytomonitors and/or phytoremediators.
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Affiliation(s)
- Erika Bellini
- Department of Biology, University of Pisa, 56126 Pisa, Italy; (E.B.); (L.S.d.T.)
| | - Camilla Betti
- Department of Medicine, University of Perugia, 06132 Perugia, Italy
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18
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Rono JK, Le Wang L, Wu XC, Cao HW, Zhao YN, Khan IU, Yang ZM. Identification of a new function of metallothionein-like gene OsMT1e for cadmium detoxification and potential phytoremediation. CHEMOSPHERE 2021; 265:129136. [PMID: 33276998 DOI: 10.1016/j.chemosphere.2020.129136] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/07/2020] [Accepted: 11/25/2020] [Indexed: 05/27/2023]
Abstract
Cadmium (Cd) is a biologically non-essential and toxic heavy metal leaking to the environment via natural emission or anthropogenic activities, thereby contaminating crops and threatening human health. Metallothioneins (MTs) are a group of metal-binding proteins playing critical roles in metal allocation and homeostasis. In this study, we identified a novel function of OsMT1e from rice plants. OsMT1e was dominantly expressed in roots at all developmental stages and, to less extent, expressed in leaves at vegetative and seed filling stages. OsMT1e was mainly targeted to the nucleus and substantially induced by Cd exposure. Expression of OsMT1e in a yeast Cd-sensitive strain ycf1 conferred cellular tolerance to Cd, even though the ycf1 + OsMT1e cells accumulated more Cd than the control cells (ycf1 + pYES2). Both transgenic rice overexpressing (OX) and repressing OsMT1e by RNA interference (RNAi) were developed. Phenotypic analysis revealed that OsMT1e overexpression enhanced the rice growth concerning the increased shoot or root elongation, dry weight and chlorophyll contents, whereas the RNAi lines displayed a sensitive growth phenotype compared to wild-type. Assessment with 0.5, 2 and 10 μM Cd for two weeks revealed that the RNAi lines accumulated less Cd, while the OX lines had an increased Cd accumulation in root and shoot tissues. The contrasting Cd accumulation phenotypes between the OX and RNAi lines were further confirmed by a long-term study with 0.5 μM Cd for one month. Overall, the study unveiled a new function of OsMT1e in rice, which can be potentially used for engineering genotypes for phytoremediation or minimizing Cd in rice crops.
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Affiliation(s)
- Justice Kipkorir Rono
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Le Le Wang
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xue Chun Wu
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hong Wei Cao
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ya Ning Zhao
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Irfan Ullah Khan
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhi Min Yang
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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Rai KK, Pandey N, Meena RP, Rai SP. Biotechnological strategies for enhancing heavy metal tolerance in neglected and underutilized legume crops: A comprehensive review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111750. [PMID: 33396075 DOI: 10.1016/j.ecoenv.2020.111750] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 11/27/2020] [Accepted: 11/29/2020] [Indexed: 05/15/2023]
Abstract
Contamination of agricultural land and water by heavy metals due to rapid industrialization and urbanization including various natural processes have become one of the major constraints to crop growth and productivity. Several studies have reported that to counteract heavy metal stress, plants should be able to maneuver various physiological, biochemical and molecular processes to improve their growth and development under heavy metal stress. With the advent of modern biotechnological tools and techniques it is now possible to tailor legume and other plants overexpressing stress-induced genes, transcription factors, proteins, and metabolites that are directly involved in heavy metal stress tolerance. This review provides an in-depth overview of various biotechnological approaches and/or strategies that can be used for enhancing detoxification of the heavy metals by stimulating phytoremediation processes. Synthetic biology tools involved in the engineering of legume and other crop plants against heavy metal stress tolerance are also discussed herewith some pioneering examples where synthetic biology tools that have been used to modify plants for specific traits. Also, CRISPR based genetic engineering of plants, including their role in modulating the expression of several genes/ transcription factors in the improvement of abiotic stress tolerance and phytoremediation ability using knockdown and knockout strategies has also been critically discussed.
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Affiliation(s)
- Krishna Kumar Rai
- Centre of Advance Study in Botany, Department of Botany, Institute of Science, Banaras Hindu University (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Neha Pandey
- Centre of Advance Study in Botany, Department of Botany, Institute of Science, Banaras Hindu University (BHU), Varanasi 221005, Uttar Pradesh, India; Department of Botany, CMP PG College, University of Allahabad, Prayagraj, India
| | - Ram Prasad Meena
- Centre of Advance Study in Botany, Department of Botany, Institute of Science, Banaras Hindu University (BHU), Varanasi 221005, Uttar Pradesh, India; Department of Computer Science, IIT, Banaras Hindu University (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Shashi Pandey Rai
- Centre of Advance Study in Botany, Department of Botany, Institute of Science, Banaras Hindu University (BHU), Varanasi 221005, Uttar Pradesh, India.
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20
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Wong DL, Yuan AT, Korkola NC, Stillman MJ. Interplay between Carbonic Anhydrases and Metallothioneins: Structural Control of Metalation. Int J Mol Sci 2020; 21:E5697. [PMID: 32784815 PMCID: PMC7460868 DOI: 10.3390/ijms21165697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/31/2020] [Accepted: 08/05/2020] [Indexed: 12/13/2022] Open
Abstract
Carbonic anhydrases (CAs) and metallothioneins (MTs) are both families of zinc metalloproteins central to life, however, they coordinate and interact with their Zn2+ ion cofactors in completely different ways. CAs and MTs are highly sensitive to the cellular environment and play key roles in maintaining cellular homeostasis. In addition, CAs and MTs have multiple isoforms with differentiated regulation. This review discusses current literature regarding these two families of metalloproteins in carcinogenesis, with a dialogue on the association of these two ubiquitous proteins in vitro in the context of metalation. Metalation of CA by Zn-MT and Cd-MT is described. Evidence for protein-protein interactions is introduced from changes in metalation profiles of MT from electrospray ionization mass spectrometry and the metalation rate from stopped-flow kinetics. The implications on cellular control of pH and metal donation is also discussed in the context of diseased states.
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Affiliation(s)
| | | | | | - Martin J. Stillman
- Department of Chemistry, The University of Western Ontario, 1151 Richmond St., London, ON N6A5B7, Canada; (D.L.W.); (A.T.Y.); (N.C.K.)
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21
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Malekzadeh R, Shahpiri A, Siapoush S. Metalation of a rice type 1 metallothionein isoform (OsMTI-1b). Protein Expr Purif 2020; 175:105719. [PMID: 32750405 DOI: 10.1016/j.pep.2020.105719] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 06/11/2020] [Accepted: 07/25/2020] [Indexed: 11/15/2022]
Abstract
The simultaneously functions of Metallothioneins (MTs) are relied on their metalation mechanisms that can be divided into non-cooperative, weakly cooperative and strongly cooperative mechanisms. In this study, we recombinantly synthesized OsMTI-1b, N- and C-terminal Cys-rich regions as glutathione-S-transferase (GST)-fusion proteins in E. coli. In comparison with control strains (The E. coli cells containing pET41a without gene), transgenic E. coli cells showed more tolerance against Cd2+ and Zn2+. The recombinant GST-proteins were purified using affinity chromatography. According to in vitro assays, the recombinant proteins showed a higher binding ability to Cd2+ and Zn2+. However, the affinity of apo-proteins to Cu2+ ions were very low. The coordination of Cd2+ ions in OsMTI-1b demonstrates a strongly cooperative mechanism with a priority for the C-terminal Cys-rich region that indicates the detoxifying of heavy metals as main role of P1 subfamily of MTs. While the metalation with Zn2+ conformed to a weakly cooperative mechanism with a specificity to N-terminal Cys-rich region. It implies the specific function of OsMTI-1b is involved in zinc homeostasis. Nevertheless, a non-cooperative metalation mechanism was perceived for Cu2+ that suggests the fully metalation does not occur and OsMTI-1b cannot play a significant role in dealing with Cu2+ ions.
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Affiliation(s)
- Rahim Malekzadeh
- Department of Medical Biotechnology, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, 88157-13471, Iran; Student Research Committee, Shahrekord University of Medical Sciences, Shahrekord, Iran.
| | - Azar Shahpiri
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Samaneh Siapoush
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Science, Tabriz, 51664-15731, Iran
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22
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Mekawy AMM, Assaha DVM, Ueda A. Constitutive overexpression of rice metallothionein-like gene OsMT-3a enhances growth and tolerance of Arabidopsis plants to a combination of various abiotic stresses. JOURNAL OF PLANT RESEARCH 2020; 133:429-440. [PMID: 32253631 DOI: 10.1007/s10265-020-01187-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
Metallothioneins (MT) are primarily involved in metal chelation. Recent studies have shown that MT proteins are also involved in the responses of plants to various environmental stresses. The rice metallothionein-like gene OsMT-3a is upregulated by salinity and various abiotic stressors. A DNA construct containing the complete OsMT-3a coding sequence cloned downstream to the CaMV35S promoter was transformed into Arabidopsis and homozygous single-copy transgenic lines were produced. Compared to wild-type plants, transgenic plants showed substantially increased salinity tolerance (NaCl), drought tolerance (PEG), and heavy metal tolerance (CdCl2) as individual stresses, as well as different combinations of these stresses. Relevantly, under unstressed control conditions, vegetative growth of transgenic plants was also improved. The shoot Na+ concentration and hydrogen peroxide in transgenic plants were lower than those in wild-type plants. OsMT-3a-overexpressing Arabidopsis lines accumulated higher levels of Cd2+ in both shoots and roots following CdCl2 treatment. In the transgenic MT-3a lines, increased activity of two major antioxidant enzymes, catalase and ascorbate peroxidase, was observed. Thus, rice OsMT-3a is a valuable target gene for plant genetic improvement against multiple abiotic stresses.
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Affiliation(s)
- Ahmad Mohammad M Mekawy
- Department of Botany and Microbiology, Faculty of Science, Minia University, El-Minia, 61519, Egypt
| | - Dekoum V M Assaha
- Department of Agriculture, Higher Technical Teachers' Training College, University of Buea, PO Box 249, Kumba, SWR, Cameroon
| | - Akihiro Ueda
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-8528, Japan.
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Zhang BQ, Liu XS, Feng SJ, Zhao YN, Wang LL, Rono JK, Li H, Yang ZM. Developing a cadmium resistant rice genotype with OsHIPP29 locus for limiting cadmium accumulation in the paddy crop. CHEMOSPHERE 2020; 247:125958. [PMID: 32069726 DOI: 10.1016/j.chemosphere.2020.125958] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 01/05/2020] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Widespread contamination of agricultural soil with toxic metals such as cadmium (Cd) is a major threat to crop production and human health. Metallochaperones are a unique class of proteins that play pivotal roles in detoxifying metallic ions inside cells. In this study, we investigated the biological function of an uncharacterized metallochaperone termed OsHIPP29 in rice plants and showed that OsHIPP29 resides in the plasma membrane and nucleus and detoxifies excess Cd and Zn. OsHIPP29 was primarily expressed in shoots during the vegetative stage and in leaf sheath and spikelet at the flowering stage. It can be differentially induced by excess Cd, Zn, Cu, Fe and Mn. To identify the function of OsHIPP29 in mediating rice response to Cd stress, we examined a pair of OsHIPP29 mutants, RNAi lines and transgenic rice overexpressing OsHIPP29 (OX) under Cd stress. Both mutant and RNAi lines are sensitive to Cd in growth as reflected in decreased plant height and dry biomass. In contrast, the OX lines showed better growth under Cd exposure. Consistent with the phenotype, the OX lines accumulated less Cd in both root and shoot tissues, whereas OsHIPP29 knockout led to higher accumulation of Cd. These results point out that expression of OsHIPP29 is able to contribute to Cd detoxification by reducing Cd accumulation in rice plants. Our work highlights the significance of OsHIPP29-mediated reduced Cd in rice plants, with important implications for further developing genotypes that will minimize Cd accumulation in rice and environmental risks to human health.
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Affiliation(s)
- Bai Qing Zhang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xue Song Liu
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Sheng Jun Feng
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ya Ning Zhao
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Lei Lei Wang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Justice Kipkorir Rono
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - He Li
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhi Min Yang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China.
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Zhou Y, Liu J, Liu S, Jiang L, Hu L. Identification of the metallothionein gene family from cucumber and functional characterization of CsMT4 in Escherichia coli under salinity and osmotic stress. 3 Biotech 2019; 9:394. [PMID: 31656732 PMCID: PMC6789051 DOI: 10.1007/s13205-019-1929-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 09/29/2019] [Indexed: 12/17/2022] Open
Abstract
Metallothionein (MT) proteins are low-molecular-weight, cysteine-rich and metal-binding proteins that play important roles in the maintenance of metal homeostasis and detoxification, but their roles in abiotic stress tolerance remain largely unknown. In this study, three MT family genes (CsMT2, CsMT3 and CsMT4) were identified in the cucumber genome. CsMT2, CsMT3 and CsMT4 possessed 14, 10, and 18 Cys residues, which were clustered into 2, 2, and 3 Cys-rich regions, respectively. Phylogenetic analysis of MTs from cucumber, Arabidopsis and soybean revealed that these MTs were clustered into four groups in accordance with the MT types (types 1-4). An analysis of the cis-acting regulatory elements revealed that a series of hormone-, stress-, and development-related cis-elements were present in the promoter regions of CsMT genes. Expression pattern analysis by RT-PCR showed that the CsMT genes exhibited different tissue expression patterns. CsMT2 showed relatively higher expression in stem, leaf, and flower; CsMT3 was mainly expressed in leaf, flower, and fruit, while CsMT4 was highly expressed in fruit and leaf. The qRT-PCR results showed that the CsMT genes were induced by various stress treatments including NaCl, PEG, and ABA, while CsMT4 displayed much higher expression levels in response to these stresses than CsMT2 and CsMT3. Escherichia coli cells expressing CsMT4 exhibited higher salinity and osmotic tolerance compared with control cells, indicating the significant function of CsMT4 to confer tolerance to these stresses. These results lay a foundation for further research on the function of MT family genes in plant stress responses.
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Affiliation(s)
- Yong Zhou
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045 China
- College of Science, Jiangxi Agricultural University, Nanchang, 330045 China
- Institute of Biotechnology and Physical Agricultural Engineering, Jiangxi Agricultural University, Nanchang, 330045 China
| | - Jialin Liu
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045 China
- College of Agronomy, Jiangxi Agricultural University, Nanchang, 330045 China
| | - Shiqiang Liu
- College of Science, Jiangxi Agricultural University, Nanchang, 330045 China
- Institute of Biotechnology and Physical Agricultural Engineering, Jiangxi Agricultural University, Nanchang, 330045 China
| | - Lunwei Jiang
- Institute of Biotechnology and Physical Agricultural Engineering, Jiangxi Agricultural University, Nanchang, 330045 China
| | - Lifang Hu
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045 China
- College of Agronomy, Jiangxi Agricultural University, Nanchang, 330045 China
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25
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Gao G, Chen J, Chen P, Chen K, Abubakar AS, Yu C, Zhu A. Analysis of BnMTL, a novel metallothionein-like protein in the bast fiber crop Ramie (Boehmeria nivea). FEBS Open Bio 2019; 9:1632-1639. [PMID: 31353835 PMCID: PMC6722885 DOI: 10.1002/2211-5463.12705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/18/2019] [Accepted: 07/26/2019] [Indexed: 12/02/2022] Open
Abstract
Ramie (Boehmeria nivea) is a perennial herb that is highly tolerant of heavy metals. In the present study, we cloned a novel metallothionein-like gene from ramie; this gene, termed BnMTL, encodes a putative 46 amino acid protein with a molecular mass of 4.38 kDa. Analysis using quantitative RT-PCR revealed that cadmium (Cd2+ ) treatment results in elevated expression of BnMTL in the roots. We heterologously overexpressed BnMTL in Escherichia coli cells to examine its binding to Cd2+ and its possible role in homeostasis. Recombinant E. coli cells expressing BnMTL exhibited a high tolerance of Cd2+ stress up to a concentration of 1 mm, and the observed accumulation of Cd2+ was almost eight-fold higher than the control. These results demonstrate that BnMTL (i) is highly expressed in the root following exposure to Cd2+ and (ii) encodes a typical metallothionein-like protein with high cadmium-binding activity.
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Affiliation(s)
- Gang Gao
- Institute of Bast Fiber CropsChinese Academy of Agricultural SciencesChangshaChina
| | - Jikang Chen
- Institute of Bast Fiber CropsChinese Academy of Agricultural SciencesChangshaChina
| | - Ping Chen
- Institute of Bast Fiber CropsChinese Academy of Agricultural SciencesChangshaChina
| | - Kunmei Chen
- Institute of Bast Fiber CropsChinese Academy of Agricultural SciencesChangshaChina
| | - Aminu Shehu Abubakar
- Institute of Bast Fiber CropsChinese Academy of Agricultural SciencesChangshaChina
| | - Chunming Yu
- Institute of Bast Fiber CropsChinese Academy of Agricultural SciencesChangshaChina
| | - Aiguo Zhu
- Institute of Bast Fiber CropsChinese Academy of Agricultural SciencesChangshaChina
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26
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Talebi M, Tabatabaei BES, Akbarzadeh H. Hyperaccumulation of Cu, Zn, Ni, and Cd in Azolla species inducing expression of methallothionein and phytochelatin synthase genes. CHEMOSPHERE 2019; 230:488-497. [PMID: 31121512 DOI: 10.1016/j.chemosphere.2019.05.098] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/01/2019] [Accepted: 05/13/2019] [Indexed: 05/09/2023]
Abstract
Azolla is a floating aquatic fern, having amazing capacity for concentrating toxic heavy metals. Metallothioneins (MTs) and phytochelatins (PCs) are well-defined heavy metal-binding ligands in plants. Bioaccumulation potential of different Azolla species varies according to their heavy metal ions. Therefore, the accumulation of Ni, Zn, Cu, and Cd was studied in A. pinnata, A. filiculoides, and a sample taken from Anzali wetland. Moreover, the expression of metallothionein and phytochelatin synthase encoding genes was examined at different metal concentrations. The highest level of Cu and Cd absorption was detected in A. pinnata, while the maximum amount of Ni and Zn absorption was observed in A. filiculoides and the sample taken from Anzali, respectively. The MT2 and PCS1 gene expression patterns were significantly induced by the heavy metal treatments, confirming their roles in phytoremediation potential of Azolla. However, as the results concerning heavy metal accumulation and gene expression vary in different species, only specific species of Azolla can be used for special purposes. It can be concluded that the Azolla is a good candidate for phytoremediation purposes, and the formation of phytochelatin-heavy metal complexes and their sequestration in vacuole are the main processes influencing susceptibility of Azolla to heavy metals.
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Affiliation(s)
- Majid Talebi
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156 83111, Iran.
| | | | - Hamid Akbarzadeh
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156 83111, Iran
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27
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Chang CY, Lee KW, Wu CS, Huang YH, Chang HC, Chen CL, Li CT, Li MJ, Chang CF, Chen PW. Identification of sugar response complex in the metallothionein OsMT2b gene promoter for enhancement of foreign protein production in transgenic rice. PLANT CELL REPORTS 2019; 38:899-914. [PMID: 31004187 DOI: 10.1007/s00299-019-02411-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/12/2019] [Indexed: 06/09/2023]
Abstract
A 146-bp sugar response complex MTSRC is identified in the promoter of rice metallothionein OsMT2b gene conferring high-level expression of luciferase reporter gene and bioactive recombinant haFGF in transgenic rice. A rice subfamily type 2 plant metallothionein (pMT) gene, OsMT2b, encoding a reactive oxygen species (ROS) scavenger protein, has been previously shown to exhibit the most abundant gene expression in young rice seedling. Expression of OsMT2b was found to be regulated negatively by ethylene and hydrogen peroxide in rice stem node under flooding stress, but little is known about its response to sugar depletion. In this study, transient expression assay and transgenic approach were employed to characterize the regulation of the OsMT2b gene expression in rice. We found that the expression of OsMT2b gene is induced by sugar starvation in both rice suspension cells and germinated embryos. Deletion analysis and functional assay of the OsMT2b promoter revealed that the 5'-flanking region of the OsMT2b between nucleotides - 351 and - 121, which contains the sugar response complex (- 266 to - 121, designated MTSRC) is responsible for high-level promoter activity under sugar starvation. It was also found that MTSRC significantly enhances the Act1 promoter activity in transgenic rice cells and seedlings. The modified Act1 promoter, Act1-MTSRC, was used to produce the recombinant human acidic fibroblast growth factor (haFGF) in rice cells. Our result shows that the bioactive recombinant haFGF is stably produced in transformed rice cell culture and yields are up to 2% of total medium proteins. Our studies reveal that MTSRC serves as a strong transcriptional activator and the Act1-MTSRC promoter can be applicable in establishing an efficient expression system for the high-level production of foreign proteins in transgenic rice cells and seedlings.
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Affiliation(s)
- Chia-Yu Chang
- Department of BioAgricultural Sciences, National Chiayi University, Chiayi, 60004, Taiwan
| | - Kuo-Wei Lee
- Department of BioAgricultural Sciences, National Chiayi University, Chiayi, 60004, Taiwan
| | - Chung-Shen Wu
- Department of BioAgricultural Sciences, National Chiayi University, Chiayi, 60004, Taiwan
| | - Yu-Hsing Huang
- Department of BioAgricultural Sciences, National Chiayi University, Chiayi, 60004, Taiwan
| | - Ho-Chun Chang
- Department of BioAgricultural Sciences, National Chiayi University, Chiayi, 60004, Taiwan
| | | | - Chen-Tung Li
- PRIT Biotech Co., Ltd., Chunan, 35053, Miaoli, Taiwan
| | - Min-Jeng Li
- Department of BioAgricultural Sciences, National Chiayi University, Chiayi, 60004, Taiwan
| | - Chung-Fu Chang
- Department of BioAgricultural Sciences, National Chiayi University, Chiayi, 60004, Taiwan
| | - Peng-Wen Chen
- Department of BioAgricultural Sciences, National Chiayi University, Chiayi, 60004, Taiwan.
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28
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Khan IU, Rono JK, Zhang BQ, Liu XS, Wang MQ, Wang LL, Wu XC, Chen X, Cao HW, Yang ZM. Identification of novel rice (Oryza sativa) HPP and HIPP genes tolerant to heavy metal toxicity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 175:8-18. [PMID: 30878662 DOI: 10.1016/j.ecoenv.2019.03.040] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 03/06/2019] [Accepted: 03/10/2019] [Indexed: 05/27/2023]
Abstract
HPP (heavy metal associated plant protein) and HIPP (heavy metal associated isoprenylated plant protein) are a group of metal-binding metallochaperones playing crucial roles in metal homeostasis and detoxification. Up to now, only few of them have been functionally identified in plants. Here, we identified 54 HPP and HIPP genes in rice genome. Analysis of the transcriptome datasets of the rice genome exposed to cadmium (Cd) revealed 17 HPP/HIPP genes differentially expressed, with 11 being upregulated (>2 fold change, p < 0.05). Comprehensive analysis of transcripts by qRT-PCR showed that both types of genes displayed diverse expression pattern in rice under excess manganese (Mn), copper (Cu) and Cd stress. Multiple genomic analyses of HPPs/HIPPs including phylogenesis, conserved domains and motifs, genomic arrangement and genomic and tandem duplication were performed. To identify the role of the genes, OsHIPP16, OsHIPP34 and OsHIPP60 were randomly selected to express in yeast (Saccharomyces cerevisiae) mutants pmrl, cup2, ycf1 and zrc1, exhibiting sensitivity to Mn, Cu, Cd and Zn toxicity, respectively. Complementation test showed that the transformed cells accumulated more metals in the cells, but their growth status was improved. To confirm the functional role, two mutant oshipp42 lines defective in OsHIPP42 expression were identified under metal stress. Under normal condition, no difference of growth between the oshipp42 mutant and wild-type plants was observed. Upon excess Cu, Zn, Cd and Mn, the oshipp42 lines grew weaker than the wild-type. Our work provided a novel source of heavy metal-binding genes in rice that can be potentially used to develop engineered plants for phytoremediation in heavy metal-contaminated soils.
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Affiliation(s)
- Irfan Ullah Khan
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Justice Kipkoir Rono
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Bai Qing Zhang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Xue Song Liu
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Meng Qi Wang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Lei Lei Wang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Xue Chun Wu
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Xi Chen
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Hong Wei Cao
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhi Min Yang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China.
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Yu XZ, Lin YJ, Zhang Q. Metallothioneins enhance chromium detoxification through scavenging ROS and stimulating metal chelation in Oryza sativa. CHEMOSPHERE 2019; 220:300-313. [PMID: 30590296 DOI: 10.1016/j.chemosphere.2018.12.119] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/11/2018] [Accepted: 12/17/2018] [Indexed: 05/03/2023]
Abstract
Metallothioneins (MTs) is a metal ion binding protein to detoxify heavy metal stress in plant cells. This study examines involvement of MTs in metal chelation and ROS scavenging in rice seedling under Cr induction either Cr(VI) or Cr(III) at three different effective concentrations using Agilent 44K rice microarray and real-time PCR technology. Results showed that the concentration of Cr was higher in roots than in shoots in both Cr treatments. Accumulation of both H2O2 and O2- in rice tissues was evident, but the fluctuation of H2O2 was more remarkable than O2-. Both Cr exposures resulted in enhancement of MTs in plant tissues. Results from PCR analysis confirmed that ten specific OsMT genes responsible for regulating ROS removal were expressed differentially in plant tissues as well as in Cr variants, suggesting that their different regulation and responsiveness strategies. Expression patterns of metal chelation-related OsMT genes, after Cr exposure were also inconsistent in rice tissues. Longer exposure periods caused more transcriptional changes in both Cr treatments. We also noticed that OsMT1b might carry more weight during Cr chelation in roots rather than in shoots, while OsMT2c had more important role in eliminating H2O2 accumulation in shoots than roots. These results suggest that different speciation of Cr in rice tissues resulted in inconsistent transcriptional changes of OsMT genes, which functioned in different regulation and responsiveness pathways responsible for metal ions chelating and ROS scavenging during Cr detoxification.
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Affiliation(s)
- Xiao-Zhang Yu
- The Guangxi Key Laboratory of Theory & Technology for Environmental Pollution Control, College of Environmental Science & Engineering, Guilin University of Technology, Guilin 541004, People's Republic of China.
| | - Yu-Juan Lin
- The Guangxi Key Laboratory of Theory & Technology for Environmental Pollution Control, College of Environmental Science & Engineering, Guilin University of Technology, Guilin 541004, People's Republic of China
| | - Qing Zhang
- The Guangxi Key Laboratory of Theory & Technology for Environmental Pollution Control, College of Environmental Science & Engineering, Guilin University of Technology, Guilin 541004, People's Republic of China
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30
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Manceau A, Bustamante P, Haouz A, Bourdineaud JP, Gonzalez‐Rey M, Lemouchi C, Gautier‐Luneau I, Geertsen V, Barruet E, Rovezzi M, Glatzel P, Pin S. Mercury(II) Binding to Metallothionein in Mytilus edulis revealed by High Energy-Resolution XANES Spectroscopy. Chemistry 2019; 25:997-1009. [PMID: 30426580 PMCID: PMC6582439 DOI: 10.1002/chem.201804209] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Indexed: 11/26/2022]
Abstract
Of all divalent metals, mercury (HgII ) has the highest affinity for metallothioneins. HgII is considered to be enclosed in the α and β domains as tetrahedral α-type Hg4 Cys11-12 and β-type Hg3 Cys9 clusters similar to CdII and ZnII . However, neither the four-fold coordination of Hg nor the existence of Hg-Hg atomic pairs have ever been demonstrated, and the HgII partitioning among the two protein domains is unknown. Using high energy-resolution XANES spectroscopy, MP2 geometry optimization, and biochemical analysis, evidence for the coexistence of two-coordinate Hg-thiolate complex and four-coordinate Hg-thiolate cluster with a metacinnabar-type (β-HgS) structure in the α domain of separate metallothionein molecules from blue mussel under in vivo exposure is provided. The findings suggest that the CXXC claw setting of thiolate donors, which only exists in the α domain, acts as a nucleation center for the polynuclear complex and that the five CXC motifs from this domain serve as the cluster-forming motifs. Oligomerization is driven by metallophilic Hg⋅⋅⋅Hg interactions. Our results provide clues as to why Hg has higher affinity for the α than the β domain. More generally, this work provides a foundation for understanding how metallothioneins mediate mercury detoxification in the cell under in vivo conditions.
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Affiliation(s)
- Alain Manceau
- ISTerreUniv. Grenoble Alpes, CNRS38000GrenobleFrance
| | - Paco Bustamante
- Littoral Environnement et Sociétés, LIENSs, Univ. La RochelleCNRS17000La RochelleFrance
| | - Ahmed Haouz
- Institut Pasteur, Plate-forme de CristallographieCNRS,375724ParisFrance
| | | | | | | | | | - Valérie Geertsen
- NIMBE, Univ. Paris-SaclayCNRS, CEA Saclay91191Gif-sur-YvetteFrance
| | - Elodie Barruet
- NIMBE, Univ. Paris-SaclayCNRS, CEA Saclay91191Gif-sur-YvetteFrance
| | - Mauro Rovezzi
- European Synchrotron Radiation FacilityESRF38000GrenobleFrance
| | - Pieter Glatzel
- European Synchrotron Radiation FacilityESRF38000GrenobleFrance
| | - Serge Pin
- NIMBE, Univ. Paris-SaclayCNRS, CEA Saclay91191Gif-sur-YvetteFrance
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31
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Wong DL, Korkola NC, Stillman MJ. Kinetics of competitive Cd2+ binding pathways: the realistic structure of intrinsically disordered, partially metallated metallothioneins. Metallomics 2019; 11:894-905. [DOI: 10.1039/c8mt00347e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The metallation of metallothionein can proceed via two different intermediate structures: a beaded structure that forms quickly (top) and a slow-forming cluster structure (bottom) before forming the fully metallated two-domain protein.
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Affiliation(s)
- Daisy L. Wong
- Department of Chemistry
- the University of Western Ontario
- Ontario
- Canada
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32
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Huang YY, Gong FY, Shen C, He CT, Fu HL, Wang XS, Tan X, Xu PL, Yang ZY. Cloning, characterization and expression analysis of metallothioneins from Ipomoea aquatica and their cultivar-dependent roles in Cd accumulation and detoxification. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 165:450-458. [PMID: 30218968 DOI: 10.1016/j.ecoenv.2018.08.089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/18/2018] [Accepted: 08/23/2018] [Indexed: 06/08/2023]
Abstract
To explore the possible roles of metallothioneins (MTs) played in cadmium (Cd) accumulation of water spinach, three IaMT genes, IaMT1, IaMT2 and IaMT3 in a high-shoot-Cd (T308) and a low-shoot-Cd accumulation cultivar (QLQ) were cloned, characterized, and quantitated. Gene expression analysis suggested that the expression of the IaMTs was differentially regulated by Cd stress in different cultivars, and T308 showed higher MTs expression overall. Furthermore, only shoot IaMT3 expression was cultivar dependent among the three IaMTs. Antioxidant analysis showed that the high production of IaMTs in T308 should be associated with its high oxidation resistance. The role of IaMTs in protecting against Cd toxicity was demonstrated in vitro via recombinant E. coli strains. The results showed that IaMT1 correlated with neither Cd tolerance nor Cd accumulation of E. coli, while IaMT2 conferred Cd tolerance in E. coli, IaMT2 and IaMT3 increased Cd accumulation in E. coli. These findings help to clarify the roles of IaMTs in Cd accumulation, and increase our understanding of the cultivar-dependent Cd accumulation in water spinach.
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Affiliation(s)
- Ying-Ying Huang
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China
| | - Fei-Yue Gong
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China
| | - Chuang Shen
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China
| | - Chun-Tao He
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China
| | - Hui-Ling Fu
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China
| | - Xue-Song Wang
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China
| | - Xiao Tan
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China
| | - Pei-Lin Xu
- State Key Laboratory of Biocontrol, Biotechnology Research Center, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China.
| | - Zhong-Yi Yang
- State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, China.
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Tomàs Giner M, Jiménez-Martí E, Bofill Arasa R, Tinti A, Di Foggia M, Chatgilialoglu C, Torreggiani A. Analysis of the soybean metallothionein system under free radical stress: protein modification connected to lipid membrane damage. Metallomics 2018; 10:1792-1804. [PMID: 30398507 DOI: 10.1039/c8mt00164b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Metallothioneins are small Cys-rich peptides capable of coordinating metal ions, and proposed to be involved in radical stress. The four Zn(ii)-GmMT complexes of soybean (Glycine max) were recombinantly synthesised and exposed to oxidative (HO˙) and reductive (H˙ atoms and eaq-) stress conditions. Gamma-irradiation was used to simulate the endogenous formation of the reactive species in both aqueous solutions and unsaturated lipid vesicle suspensions, a biomimetic model that showed that tandem protein/lipid damage occurs, in particular under reductive radical stress. This is due to the formation of diffusible sulphur-centred radicals, which migrate from the aqueous phase to the lipid bilayer and are thus able to transform the cis double bond of the oleate moiety into the trans isomer. Among the amino acid residues present in GmMTs, Cys is one of the most sensitive residues towards the attack of free radicals, thus suggesting metal-clusters to be good interceptors of free radicals. Also Met, Tyr and Phe residues are sensitive amino acid sites of attack under both oxidative and reductive conditions. The modification of the Zn(ii)-GmMT complexes, in particular isoform 2, was monitored by Raman spectroscopy and mass spectrometry. Free radical stress on the Zn(ii)-GmMT complexes is able to induce significant structural changes such as partial deconstruction and/or rearrangement of the metal clusters, but not the complete demetallation of the proteins nor breaking of the backbone, thus confirming their capability to act as protectors under free radical stress conditions.
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Affiliation(s)
- Mireia Tomàs Giner
- Dep. Genètica, Facultat de Biologia, Univ. Barcelona, Av. Diagonal 645, 08028 Barcelona, Catalonia, Spain.
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Xu X, Duan L, Yu J, Su C, Li J, Chen D, Zhang X, Song H, Pan Y. Characterization analysis and heavy metal-binding properties of CsMTL3 in Escherichia coli. FEBS Open Bio 2018; 8:1820-1829. [PMID: 30410861 PMCID: PMC6212650 DOI: 10.1002/2211-5463.12520] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/16/2018] [Accepted: 08/29/2018] [Indexed: 11/30/2022] Open
Abstract
Members of the metallothionein (MT) superfamily are involved in coordinating transition metal ions. In plants, MT family members are characterized by their arrangement of Cys residues. In this study, one member of the MT superfamily, CsMTL3, was characterized from a complementary DNA (cDNA) library from young cucumber fruit; CsMTL3 is predicted to encode a 64 amino acid protein with a predicted molecular mass of 6.751 kDa. Phylogenetic analysis identified it as a type 3 family member as the arrangement of N-terminal Cys residues was different from that of MT-like 2. Heterologous expression of CsMTL3 in Escherichia coli improved their heavy metal tolerance, particularly to Cd2+ and Cu2+, and led to increased uptake of Cd2+ and Cu2+; increased uptake was also observed for cells expressing Arabidopsis thaliana metallothionein 3 (AtMT3) and phytochelatin-like (PCL), with greatest uptake in PCL-expressing cells. These findings demonstrate that CsMTL3 can improve metal tolerance, especially for Cd2+ ions, when heterologously expressed in E. coli, and suggest that the composition and arrangement of N-terminal Cys residues are associated with binding capacity and preference for different metal ions.
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Affiliation(s)
- Xing Xu
- Key Laboratory of Horticulture Science for Southern Mountainous RegionsMinistry of EducationSouthwest UniversityChongqingChina
- College of Horticulture and Landscape ArchitectureSouthwest UniversityChongqingChina
| | - Ling Duan
- Key Laboratory of Horticulture Science for Southern Mountainous RegionsMinistry of EducationSouthwest UniversityChongqingChina
- College of Horticulture and Landscape ArchitectureSouthwest UniversityChongqingChina
| | - Jingwen Yu
- Key Laboratory of Horticulture Science for Southern Mountainous RegionsMinistry of EducationSouthwest UniversityChongqingChina
- College of Horticulture and Landscape ArchitectureSouthwest UniversityChongqingChina
| | - Chenggang Su
- Key Laboratory of Horticulture Science for Southern Mountainous RegionsMinistry of EducationSouthwest UniversityChongqingChina
- College of Horticulture and Landscape ArchitectureSouthwest UniversityChongqingChina
| | - Jinhua Li
- Key Laboratory of Horticulture Science for Southern Mountainous RegionsMinistry of EducationSouthwest UniversityChongqingChina
- College of Horticulture and Landscape ArchitectureSouthwest UniversityChongqingChina
| | - Dan Chen
- Comprehensive Testing Center of Guangzhou Entry‐Exit Inspection & Quarantine BureauGuangzhouChina
| | - Xingguo Zhang
- Key Laboratory of Horticulture Science for Southern Mountainous RegionsMinistry of EducationSouthwest UniversityChongqingChina
- College of Horticulture and Landscape ArchitectureSouthwest UniversityChongqingChina
| | - Hongyuan Song
- Key Laboratory of Horticulture Science for Southern Mountainous RegionsMinistry of EducationSouthwest UniversityChongqingChina
- College of Horticulture and Landscape ArchitectureSouthwest UniversityChongqingChina
| | - Yu Pan
- Key Laboratory of Horticulture Science for Southern Mountainous RegionsMinistry of EducationSouthwest UniversityChongqingChina
- College of Horticulture and Landscape ArchitectureSouthwest UniversityChongqingChina
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Scheller JS, Irvine GW, Stillman MJ. Unravelling the mechanistic details of metal binding to mammalian metallothioneins from stoichiometric, kinetic, and binding affinity data. Dalton Trans 2018; 47:3613-3637. [PMID: 29431781 DOI: 10.1039/c7dt03319b] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Metallothioneins (MTs) are small, cysteine-rich proteins, found throughout Nature. Their ability to bind a number of different metals with a range of stoichiometric ratios means that this protein family is critically important for essential metal (Zn2+ and Cu+) homeostasis, metal storage, metal donation to nascent metalloenzymes as well as heavy metal detoxification. With its 20 cysteines, metallothionein is also considered to protect cells against oxidative stress. MT has been studied by a large number of researchers over the last 6 decades using a variety of spectroscopic techniques. The lack of distinguishing chromophores for the multitude of binding sites has made the evaluation of stoichiometric properties for different metals challenging. Initially, only 113Cd-NMR spectroscopy could provide strong evidence for the proposed cluster formation of Cd-MT. The extraordinary development of electrospray ionization mass spectrometry (ESI-MS), where all coexisting species in solution are observed, revolutionized MT research. Prior to the use of ESI-MS data, a range of "magic numbers" representing metal-to-MT molar ratios were reported from optical spectroscopic studies. The availability of ESI mass spectral data led to (i) the confirmation of cluster formation, (ii) a conceptual understanding of the cooperativity involved in multiple metal binding events, (iii) the presence of domain specificity between regions of the protein and (iv) mechanistic details involving both binding affinities and rate constants. The kinetic experiments identified the presence of multiple individual binding sites, each with a unique rate constant and an analogous binding affinity. The almost linear trend in rate constants as a function of bound As3+ provided a unique insight that became a critical step in the complete understanding of the mechanistic details of the metalation of MT. To fully define the biological function of this sulfur-rich protein it is necessary to determine kinetic rate constants and binding affinities for the essential metals. Recently, Zn2+ competition experiments between both of the isolated fragments (α and β) and the full-length protein (βα-MT 1a) as well as Zn2+ competition between βα-MT 1a and carbonic anhydrase were reported. From these data, the trend in binding affinities and the values of the Kf of the 7 bimolecular reactions involved in metalation were determined. From the analysis of ESI-MS data for Cu+ binding to βα-MT 1a at different pH-values, a trend in the 20 binding affinities for the complete metalation mechanism was reported. This review details a personal view of the historical development of the determination of stoichiometry for metal binding, the structure of the binding sites, the rates of the metalation reactions and the underlying binding affinities for each metalation step. We have attempted to summarize the experimental developments that led to the publication in May 2017 of the experimental determination of the 20 binding constants for the 20 sequential bimolecular reactions for Cu+ binding to the 20 Cys of apoMT as a function of pH that show the appearance and disappearance of clusters. We report both published data and in a series of tables an assembly of stoichiometries, and equilibrium constants for Zn2+ and Cu+ for many different metallothioneins.
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Affiliation(s)
- Judith S Scheller
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
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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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Wong DL, Stillman MJ. Capturing platinum in cisplatin: kinetic reactions with recombinant human apo-metallothionein 1a. Metallomics 2018; 10:713-721. [DOI: 10.1039/c8mt00029h] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Detailed mass spectra data show the stepwise sequence of cisplatin deconstruction by apo-metallothionein.
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Affiliation(s)
- Daisy L. Wong
- Stillman Bioinorganic Group
- Department of Chemistry
- The University of Western Ontario, London
- Ontario
- Canada N6A 5B7
| | - Martin J. Stillman
- Stillman Bioinorganic Group
- Department of Chemistry
- The University of Western Ontario, London
- Ontario
- Canada N6A 5B7
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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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Cabral ACS, Jakovleska J, Deb A, Penner-Hahn JE, Pecoraro VL, Freisinger E. Further insights into the metal ion binding abilities and the metalation pathway of a plant metallothionein from Musa acuminata. J Biol Inorg Chem 2018; 23:91-107. [PMID: 29218632 PMCID: PMC5756683 DOI: 10.1007/s00775-017-1513-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/07/2017] [Indexed: 10/18/2022]
Abstract
The superfamily of metallothioneins (MTs) combines a diverse group of metalloproteins, sharing the characteristics of rather low molecular weight and high cysteine content. The latter provides MTs with the capability to coordinate thiophilic metal ions, in particular those with a d 10 electron configuration. The sub-family of plant MT3 proteins is only poorly characterized and there is a complete lack of three-dimensional structure information. Building upon our previous results on the Musa acuminata MT3 (musMT3) protein, the focus of the present work is to understand the metal cluster formation process, the role of the single histidine residue present in musMT3, and the metal ion binding affinity. We concentrate our efforts on the coordination of ZnII and CdII ions, using CoII as a spectroscopic probe for ZnII binding. The overall protein-fold is analysed with a combination of limited proteolytic digestion, mass spectrometry, and dynamic light scattering. Histidine coordination of metal ions is probed with extended X-ray absorption fine structure spectroscopy and CoII titration experiments. Initial experiments with isothermal titration calorimetry provide insights into the thermodynamics of metal ion binding.
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Affiliation(s)
- Augusto C S Cabral
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Jovana Jakovleska
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Aniruddha Deb
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA
| | - James E Penner-Hahn
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA
| | - Vincent L Pecoraro
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI, 48109, USA
| | - Eva Freisinger
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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Mierek-Adamska A, Dąbrowska GB, Blindauer CA. The type 4 metallothionein from Brassica napus seeds folds in a metal-dependent fashion and favours zinc over other metals. Metallomics 2018; 10:1430-1443. [DOI: 10.1039/c8mt00161h] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rapeseed MT4 only folds properly in the presence of Zn2+ and thus may serve as a selectivity filter for metal accumulation in plant embryos.
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Affiliation(s)
- Agnieszka Mierek-Adamska
- Department of Genetics
- Faculty of Biology and Environmental Protection
- Nicolaus Copernicus University
- 87-100 Toruń
- Poland
| | - Grażyna B. Dąbrowska
- Department of Genetics
- Faculty of Biology and Environmental Protection
- Nicolaus Copernicus University
- 87-100 Toruń
- Poland
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Liang X, Qin X, Huang Q, Huang R, Yin X, Cai Y, Wang L, Sun Y, Xu Y. Remediation mechanisms of mercapto-grafted palygorskite for cadmium pollutant in paddy soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:23783-23793. [PMID: 28866741 DOI: 10.1007/s11356-017-0014-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
The immobilization agent was the key factor that determined the success of remediation of heavy metal polluted soil. In this study, mercapto-grafted palygorskite (MP) as a novel and efficient immobilization agent was utilized for the remediation of Cd-polluted paddy soil in pot trials, and the remediation mechanisms were investigated in the aspect of soil chemistry and plant physiology with different rice cultivars as model plants. Mercapto-grafted palygorskite at applied doses of 0.1-0.3% could reduce Cd contents of brown rice and straws of different cultivars significantly. Both reduced DTPA-extractable Cd contents in rhizosphere and non-rhizosphere soil and decreasing Cd contents in iron plaques on rice root surfaces confirmed that MP was an efficient immobilization agent for Cd pollutant in paddy soil. In the aspect of soil chemistry, the pH values of rhizosphere and non-rhizosphere soils had no statistical changes in the MP treatment groups, but their zeta potentials decreased obviously, indicating that MP could enhance the fixation or sorption of Cd on soil compositions. In the aspect of antioxidant system, MP could increase POD activity of rice roots significantly to alleviate the stress of Cd to roots, and resulted in the decrease of T-AOC, SOD, and CAT activities of rice roots of the selected cultivars. MP had no inhabitation or enhancement effects on TSH of rice roots but enhance the contents of MTs and NPT to binding Cd to complete detoxification process. MP as a novel and efficient immobilization agent could complete the remediation effects through soil chemistry and plant physiological mechanisms.
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Affiliation(s)
- Xuefeng Liang
- Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, No. 31, Fukang Road, Nankai District, Tianjin, 300191, People's Republic of China
- Key Laboratory of Original Environmental Pollution Control of MOA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, 300191, People's Republic of China
| | - Xu Qin
- Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, No. 31, Fukang Road, Nankai District, Tianjin, 300191, People's Republic of China
- Key Laboratory of Original Environmental Pollution Control of MOA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, 300191, People's Republic of China
| | - Qingqing Huang
- Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, No. 31, Fukang Road, Nankai District, Tianjin, 300191, People's Republic of China
- Key Laboratory of Original Environmental Pollution Control of MOA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, 300191, People's Republic of China
| | - Rong Huang
- Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, No. 31, Fukang Road, Nankai District, Tianjin, 300191, People's Republic of China
- Key Laboratory of Original Environmental Pollution Control of MOA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, 300191, People's Republic of China
| | - Xiuling Yin
- College of Environment and Resources, Jilin University, Changchun, 130021, People's Republic of China
| | - Yanming Cai
- Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, No. 31, Fukang Road, Nankai District, Tianjin, 300191, People's Republic of China
- Key Laboratory of Original Environmental Pollution Control of MOA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, 300191, People's Republic of China
| | - Lin Wang
- Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, No. 31, Fukang Road, Nankai District, Tianjin, 300191, People's Republic of China
- Key Laboratory of Original Environmental Pollution Control of MOA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, 300191, People's Republic of China
| | - Yuebing Sun
- Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, No. 31, Fukang Road, Nankai District, Tianjin, 300191, People's Republic of China
- Key Laboratory of Original Environmental Pollution Control of MOA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, 300191, People's Republic of China
| | - Yingming Xu
- Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, No. 31, Fukang Road, Nankai District, Tianjin, 300191, People's Republic of China.
- Key Laboratory of Original Environmental Pollution Control of MOA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, 300191, People's Republic of China.
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The Functions of Metamorphic Metallothioneins in Zinc and Copper Metabolism. Int J Mol Sci 2017; 18:ijms18061237. [PMID: 28598392 PMCID: PMC5486060 DOI: 10.3390/ijms18061237] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/02/2017] [Accepted: 06/03/2017] [Indexed: 12/15/2022] Open
Abstract
Recent discoveries in zinc biology provide a new platform for discussing the primary physiological functions of mammalian metallothioneins (MTs) and their exquisite zinc-dependent regulation. It is now understood that the control of cellular zinc homeostasis includes buffering of Zn2+ ions at picomolar concentrations, extensive subcellular re-distribution of Zn2+, the loading of exocytotic vesicles with zinc species, and the control of Zn2+ ion signalling. In parallel, characteristic features of human MTs became known: their graded affinities for Zn2+ and the redox activity of their thiolate coordination environments. Unlike the single species that structural models of mammalian MTs describe with a set of seven divalent or eight to twelve monovalent metal ions, MTs are metamorphic. In vivo, they exist as many species differing in redox state and load with different metal ions. The functions of mammalian MTs should no longer be considered elusive or enigmatic because it is now evident that the reactivity and coordination dynamics of MTs with Zn2+ and Cu+ match the biological requirements for controlling—binding and delivering—these cellular metal ions, thus completing a 60-year search for their functions. MT represents a unique biological principle for buffering the most competitive essential metal ions Zn2+ and Cu+. How this knowledge translates to the function of other families of MTs awaits further insights into the specifics of how their properties relate to zinc and copper metabolism in other organisms.
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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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Ansarypour Z, Shahpiri A. Heterologous expression of a rice metallothionein isoform (OsMTI-1b) in Saccharomyces cerevisiae enhances cadmium, hydrogen peroxide and ethanol tolerance. Braz J Microbiol 2017; 48:537-543. [PMID: 28223030 PMCID: PMC5498412 DOI: 10.1016/j.bjm.2016.10.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 10/12/2016] [Accepted: 10/25/2016] [Indexed: 11/02/2022] Open
Abstract
Metallothioneins are a superfamily of low-molecular-weight, cysteine (Cys)-rich proteins that are believed to play important roles in protection against metal toxicity and oxidative stress. The main purpose of this study was to investigate the effect of heterologous expression of a rice metallothionein isoform (OsMTI-1b) on the tolerance of Saccharomyces cerevisiae to Cd2+, H2O2 and ethanol stress. The gene encoding OsMTI-1b was cloned into p426GPD as a yeast expression vector. The new construct was transformed to competent cells of S. cerevisiae. After verification of heterologous expression of OsMTI-1b, the new strain and control were grown under stress conditions. In comparison to control strain, the transformed S. cerevisiae cells expressing OsMTI-1b showed more tolerance to Cd2+ and accumulated more Cd2+ ions when they were grown in the medium containing CdCl2. In addition, the heterologous expression of GST-OsMTI-1b conferred H2O2 and ethanol tolerance to S. cerevisiae cells. The results indicate that heterologous expression of plant MT isoforms can enhance the tolerance of S. cerevisiae to multiple stresses.
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Affiliation(s)
- Zahra Ansarypour
- Isfahan University of Technology, College of Agriculture, Department of Biotechnology, Isfahan, Iran
| | - Azar Shahpiri
- Isfahan University of Technology, College of Agriculture, Department of Biotechnology, Isfahan, Iran.
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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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46
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Pan Y, Pan Y, Zhai J, Xiong Y, Li J, Du X, Su C, Zhang X. Cucumber Metallothionein-Like 2 (CsMTL2) Exhibits Metal-Binding Properties. Genes (Basel) 2016; 7:E106. [PMID: 27916887 PMCID: PMC5192482 DOI: 10.3390/genes7120106] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 10/24/2016] [Accepted: 11/14/2016] [Indexed: 01/25/2023] Open
Abstract
We identified a novel member of the metallothionein (MT) family, Cucumis sativus metallothionein-like 2 (CsMTL2), by screening a young cucumber fruit complementary DNA (cDNA) library. The CsMTL2 encodes a putative 77-amino acid Class II MT protein that contains two cysteine (Cys)-rich domains separated by a Cys-free spacer region. We found that CsMTL2 expression was regulated by metal stress and was specifically induced by Cd2+ treatment. We investigated the metal-binding characteristics of CsMTL2 and its possible role in the homeostasis and/or detoxification of metals by heterologous overexpression in Escherichia coli cells. Furthermore, we produced a deletion mutant form of the protein, CsMTL2m, that contained the two Cys-rich clusters but lacked the spacer region, in E. coli. We compared the metal-binding properties of CsMTL2 with those of CsMTL2m, the β domain of human metallothionein-like protein 1 (HsMTXb), and phytochelatin-like (PCL) heterologously expressed in E. coli using metal-binding assays. We found that E. coli cells expressing CsMTL2 accumulated the highest levels of Zn2+ and Cd2+ of the four transformed cell types, with levels being significantly higher than those of control cells containing empty vector. E. coli cells expressing CsMTL2 had a higher tolerance for cadmium than for zinc ions. These findings show that CsMTL2 improves metal tolerance when heterologously expressed in E. coli. Future studies should examine whether CsMTL2 improves metal tolerance in planta.
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Affiliation(s)
- Yu Pan
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China.
| | - Yanglu Pan
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China.
| | - Junpeng Zhai
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China.
- Qijiang District Bureau of Forestry, Chongqing 401420, China.
| | - Yan Xiong
- Institute of Vegetables and Flowers, Chongqing Academy of Agricultural Sciences, Chongqing 401329, China.
| | - Jinhua Li
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China.
| | - Xiaobing Du
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China.
| | - Chenggang Su
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China.
| | - Xingguo Zhang
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China.
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Ziller A, Yadav RK, Capdevila M, Reddy MS, Vallon L, Marmeisse R, Atrian S, Palacios Ò, Fraissinet-Tachet L. Metagenomics analysis reveals a new metallothionein family: Sequence and metal-binding features of new environmental cysteine-rich proteins. J Inorg Biochem 2016; 167:1-11. [PMID: 27886631 DOI: 10.1016/j.jinorgbio.2016.11.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/28/2016] [Accepted: 11/11/2016] [Indexed: 11/18/2022]
Abstract
Metallothioneins are cysteine-rich proteins, which function as (i) metal carriers in basal cell metabolism and (ii) protective metal chelators in conditions of metal excess. Metallothioneins have been characterized from different eukaryotic model and cultivable species. Presently, they are categorized in 15 families but evolutionary relationships between these metallothionein families remain unresolved. Several cysteine-rich protein encoding genes that conferred Cd-tolerance in Cd-sensitive yeast mutants have previously been isolated from soil eukaryotic metatranscriptomes. They were called CRPs for "cysteine-rich proteins". These proteins, of unknown taxonomic origins, share conserved cysteine motifs and could be considered as metallothioneins. In the present work, we analyzed these CRPs with respect to their amino acid sequence features and their metal-binding abilities towards Cd, Zn and Cu metal ions. Sequence analysis revealed that they share common features with different known metallothionein families, but also exhibit unique specific features. Noticeably, CRPs display two separate cysteine-rich domains which, when expressed separately in yeast, confer Cd-tolerance. The N-terminal domain contains some conserved atypical Cys motifs, such as one CCC and two CXCC ones. Five CRPs were expressed and purified as recombinant proteins and their metal-binding characteristics were studied. All these CRPs chelated Cd(II), Zn(II) and Cu(I), although displaying a better capacity for Zn(II) coordination. All CRPs are able to confer Cd-tolerance, and four of them confer Zn-tolerance in the Zn-sensitive zrc1Δ yeast mutant. We designated these CRPs as environmental metallothioneins belonging to a new formerly undescribed metallothionein family.
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Affiliation(s)
- Antoine Ziller
- Microbial Ecology, CNRS UMR 5557, INRA UMR 1418, Université Lyon 1, Université de Lyon, F-69622 Villeurbanne, France
| | - Rajiv Kumar Yadav
- Microbial Ecology, CNRS UMR 5557, INRA UMR 1418, Université Lyon 1, Université de Lyon, F-69622 Villeurbanne, France
| | - Mercè Capdevila
- Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, E-08193 Cerdanyola del Vallès, Barcelona, Spain
| | | | - Laurent Vallon
- Microbial Ecology, CNRS UMR 5557, INRA UMR 1418, Université Lyon 1, Université de Lyon, F-69622 Villeurbanne, France
| | - Roland Marmeisse
- Microbial Ecology, CNRS UMR 5557, INRA UMR 1418, Université Lyon 1, Université de Lyon, F-69622 Villeurbanne, France
| | - Silvia Atrian
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal 643, E-08028 Barcelona, Spain
| | - Òscar Palacios
- Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, E-08193 Cerdanyola del Vallès, Barcelona, Spain
| | - Laurence Fraissinet-Tachet
- Microbial Ecology, CNRS UMR 5557, INRA UMR 1418, Université Lyon 1, Université de Lyon, F-69622 Villeurbanne, France.
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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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Pirzadeh S, Shahpiri A. Functional characterization of a type 2 metallothionein isoform (OsMTI-2b) from rice. Int J Biol Macromol 2016; 88:491-6. [DOI: 10.1016/j.ijbiomac.2016.04.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 11/28/2022]
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50
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Tomas M, Tinti A, Bofill R, Capdevila M, Atrian S, Torreggiani A. Comparative Raman study of four plant metallothionein isoforms: Insights into their Zn(II) clusters and protein conformations. J Inorg Biochem 2016; 156:55-63. [DOI: 10.1016/j.jinorgbio.2015.12.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 12/17/2015] [Accepted: 12/28/2015] [Indexed: 02/06/2023]
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