1
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Dallinger R. Metals and metallothionein evolution in snails: a contribution to the concept of metal-specific functionality from an animal model group. Biometals 2024; 37:671-696. [PMID: 38416244 PMCID: PMC11101346 DOI: 10.1007/s10534-024-00584-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 01/10/2024] [Indexed: 02/29/2024]
Abstract
This is a critical review of what we know so far about the evolution of metallothioneins (MTs) in Gastropoda (snails, whelks, limpets and slugs), an important class of molluscs with over 90,000 known species. Particular attention will be paid to the evolution of snail MTs in relation to the role of some metallic trace elements (cadmium, zinc and copper) and their interaction with MTs, also compared to MTs from other animal phyla. The article also highlights the important distinction, yet close relationship, between the structural and metal-selective binding properties of gastropod MTs and their physiological functionality in the living organism. It appears that in the course of the evolution of Gastropoda, the trace metal cadmium (Cd) must have played an essential role in the development of Cd-selective MT variants. It is shown how the structures and Cd-selective binding properties in the basal gastropod clades have evolved by testing and optimizing different combinations of ancestral and novel MT domains, and how some of these domains have become established in modern and recent gastropod clades. In this context, the question of how adaptation to new habitats and lifestyles has affected the original MT traits in different gastropod lineages will also be addressed. The 3D structures and their metal binding preferences will be highlighted exemplarily in MTs of modern littorinid and helicid snails. Finally, the importance of the different metal requirements and pathways in snail tissues and cells for the shaping and functionality of the respective MT isoforms will be shown.
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2
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Ohse VA, Klotz LO, Priebs J. Copper Homeostasis in the Model Organism C. elegans. Cells 2024; 13:727. [PMID: 38727263 PMCID: PMC11083455 DOI: 10.3390/cells13090727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 05/13/2024] Open
Abstract
Cellular and organismic copper (Cu) homeostasis is regulated by Cu transporters and Cu chaperones to ensure the controlled uptake, distribution and export of Cu ions. Many of these processes have been extensively investigated in mammalian cell culture, as well as in humans and in mammalian model organisms. Most of the human genes encoding proteins involved in Cu homeostasis have orthologs in the model organism, Caenorhabditis elegans (C. elegans). Starting with a compilation of human Cu proteins and their orthologs, this review presents an overview of Cu homeostasis in C. elegans, comparing it to the human system, thereby establishing the basis for an assessment of the suitability of C. elegans as a model to answer mechanistic questions relating to human Cu homeostasis.
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Affiliation(s)
| | - Lars-Oliver Klotz
- Nutrigenomics Section, Institute of Nutritional Sciences, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany;
| | - Josephine Priebs
- Nutrigenomics Section, Institute of Nutritional Sciences, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany;
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3
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Zhao Y, Wang J, Huang W, Zhang D, Wu J, Li B, Li M, Liu L, Yan M. Abscisic-Acid-Regulated Responses to Alleviate Cadmium Toxicity in Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:1023. [PMID: 36903884 PMCID: PMC10005406 DOI: 10.3390/plants12051023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/12/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
High levels of cadmium (Cd) in soil can cause crop yield reduction or death. Cadmium accumulation in crops affects human and animal health as it passes through the food chain. Therefore, a strategy is needed to enhance the tolerance of crops to this heavy metal or reduce its accumulation in crops. Abscisic acid (ABA) plays an active role in plants' response to abiotic stress. The application of exogenous ABA can reduce Cd accumulation in shoots of some plants and enhance the tolerance of plants to Cd; therefore, ABA may have good application prospects. In this paper, we reviewed the synthesis and decomposition of ABA, ABA-mediated signal transduction, and ABA-mediated regulation of Cd-responsive genes in plants. We also introduced physiological mechanism underlying Cd tolerance because of ABA. Specifically, ABA affects metal ion uptake and transport by influencing transpiration and antioxidant systems, as well as by affecting the expression of metal transporter and metal chelator protein genes. This study may provide a reference for further research on the physiological mechanism of heavy metal tolerance in plants.
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Affiliation(s)
- Yuquan Zhao
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Jiaqi Wang
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Wei Huang
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
- Hunan Engineering and Technology Research Center of Hybrid Rapeseed, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Dawei Zhang
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Jinfeng Wu
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Bao Li
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
- Hunan Engineering and Technology Research Center of Hybrid Rapeseed, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Mei Li
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
- Hunan Engineering and Technology Research Center of Hybrid Rapeseed, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Lili Liu
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Mingli Yan
- Crop Research Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
- Hunan Key Laboratory of Economic Crops Genetic Improvement and Integrated Utilization, Hunan University of Science and Technology, Xiangtan 411201, China
- Hunan Engineering and Technology Research Center of Hybrid Rapeseed, Hunan Academy of Agricultural Sciences, Changsha 410125, China
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Díaz S, Aguilera Á, de Figueras CG, de Francisco P, Olsson S, Puente-Sánchez F, González-Pastor JE. Heterologous Expression of the Phytochelatin Synthase CaPCS2 from Chlamydomonas acidophila and Its Effect on Different Stress Factors in Escherichia coli. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19137692. [PMID: 35805349 PMCID: PMC9265389 DOI: 10.3390/ijerph19137692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/19/2022] [Accepted: 06/21/2022] [Indexed: 11/19/2022]
Abstract
Phytochelatins (PCs) are cysteine-rich small peptides, enzymatically synthesized from reduced glutathione (GSH) by cytosolic enzyme phytochelatin synthase (PCS). The open reading frame (ORF) of the phytochelatin synthase CaPCS2 gene from the microalgae Chlamydomonas acidophila was heterologously expressed in Escherichia coli strain DH5α, to analyze its role in protection against various abiotic agents that cause cellular stress. The transformed E. coli strain showed increased tolerance to exposure to different heavy metals (HMs) and arsenic (As), as well as to acidic pH and exposure to UVB, salt, or perchlorate. In addition to metal detoxification activity, new functions have also been reported for PCS and PCs. According to the results obtained in this work, the heterologous expression of CaPCS2 in E. coli provides protection against oxidative stress produced by metals and exposure to different ROS-inducing agents. However, the function of this PCS is not related to HM bioaccumulation.
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Affiliation(s)
- Silvia Díaz
- Department of Genetics, Physiology and Microbiology, Faculty of Biology, C. José Antonio Novais, 12, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
- Correspondence:
| | - Ángeles Aguilera
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Carolina G. de Figueras
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Patricia de Francisco
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Sanna Olsson
- Department of Forest Ecology and Genetics, Forest Research Centre (INIA, CSIC), Carretera de La Coruña, km 7.5, 28040 Madrid, Spain;
| | - Fernando Puente-Sánchez
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, 756 51 Uppsala, Sweden;
| | - José Eduardo González-Pastor
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
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Phytoremediation of Cadmium Polluted Soils: Current Status and Approaches for Enhancing. SOIL SYSTEMS 2022. [DOI: 10.3390/soilsystems6010003] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cadmium (Cd) is a heavy metal present in atmosphere, rocks, sediments, and soils without a known role in plants. It is relatively mobile and can easily enter from soil into groundwater and contaminate the food chain. Its presence in food in excess amounts may cause severe conditions in humans, therefore prevention of cadmium entering the food chain and its removal from contaminated soils are important steps in preserving public health. In the last several years, several approaches for Cd remediation have been proposed, such as the use of soil amendments or biological systems for reduction of Cd contamination. One of the approaches is phytoremediation, which involves the use of plants for soil clean-up. In this review we summarized current data on the use of different plants in phytoremediation of Cd as well as information about different approaches which have been used to enhance phytoremediation. This includes data on the increasing metal bioavailability in the soil, plant biomass, and plant accumulation capacity as well as seed priming as a promising novel approach for phytoremediation enhancing.
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Cadmium hijacks the high zinc response by binding and activating the HIZR-1 nuclear receptor. Proc Natl Acad Sci U S A 2021; 118:2022649118. [PMID: 34649987 DOI: 10.1073/pnas.2022649118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2021] [Indexed: 11/18/2022] Open
Abstract
Cadmium is an environmental pollutant and significant health hazard that is similar to the physiological metal zinc. In Caenorhabditis elegans, high zinc homeostasis is regulated by the high zinc activated nuclear receptor (HIZR-1) transcription factor. To define relationships between the responses to high zinc and cadmium, we analyzed transcription. Many genes were activated by both high zinc and cadmium, and hizr-1 was necessary for activation of a subset of these genes; in addition, many genes activated by cadmium did not require hizr-1, indicating there are at least two mechanisms of cadmium-regulated transcription. Cadmium directly bound HIZR-1, promoted nuclear accumulation of HIZR-1 in intestinal cells, and activated HIZR-1-mediated transcription via the high zinc activation (HZA) enhancer. Thus, cadmium binding promotes HIZR-1 activity, indicating that cadmium acts as a zinc mimetic to hijack the high zinc response. To elucidate the relationships between high zinc and cadmium detoxification, we analyzed genes that function in three pathways: the pcs-1/phytochelatin pathway strongly promoted cadmium resistance but not high zinc resistance, the hizr-1/HZA pathway strongly promoted high zinc resistance but not cadmium resistance, and the mek-1/sek-1/kinase signaling pathway promoted resistance to high zinc and cadmium. These studies identify resistance pathways that are specific for high zinc and cadmium, as well as a shared pathway.
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7
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Tang B, Williams PL, Xue KS, Wang JS, Tang L. Detoxification mechanisms of nickel sulfate in nematode Caenorhabditis elegans. CHEMOSPHERE 2020; 260:127627. [PMID: 32673864 DOI: 10.1016/j.chemosphere.2020.127627] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 05/19/2023]
Abstract
Nickel is the most prevailing metal allergen with the highest sensitization rate among the "TOP 25" contact allergens and can affect about 15% of the human population. It is an essential trace metal in plants, animals, and humans. However, the environmental levels of nickel are considerably higher than what is needed for human life. Exposure to high levels of nickel can lead to skin allergies, lung fibrosis, and carcinogenesis. Few existing studies have closely examined the toxicity of nickel, let alone investigated the effective detoxification pathways. Here, we developed a high-throughput screening platform to comprehensively evaluate the nickel toxicity in wild-type C. elegans and explore the underlying detoxification mechanisms in transgenic nematodes. We demonstrated that nickel exerted multiple toxic effects on growth, brood size, feeding, and locomotion in C. elegans. Of which, brood size is the most sensitive endpoint. Nickel was found to first bind to phytochelatin (PC) after entering the worms' body and this PC-Ni complex was further transported by the ABC transporter, CeHMT-1, into the coelomocytes for further detoxification. Our study also demonstrated that the high-throughput screening platform is a promising system for evaluation and investigation of the ecological risks of heavy metals.
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Affiliation(s)
- Bowen Tang
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA
| | - Phillip L Williams
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA
| | - Kathy S Xue
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA
| | - Jia-Sheng Wang
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA
| | - Lili Tang
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA.
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8
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Li M, Barbaro E, Bellini E, Saba A, Sanità di Toppi L, Varotto C. Ancestral function of the phytochelatin synthase C-terminal domain in inhibition of heavy metal-mediated enzyme overactivation. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:6655-6669. [PMID: 32936292 PMCID: PMC7586750 DOI: 10.1093/jxb/eraa386] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/17/2020] [Indexed: 05/03/2023]
Abstract
Phytochelatin synthases (PCSs) play essential roles in detoxification of a broad range of heavy metals in plants and other organisms. Until now, however, no PCS gene from liverworts, the earliest branch of land plants and possibly the first one to acquire a PCS with a C-terminal domain, has been characterized. In this study, we isolated and functionally characterized the first PCS gene from a liverwort, Marchantia polymorpha (MpPCS). MpPCS is constitutively expressed in all organs examined, with stronger expression in thallus midrib. The gene expression is repressed by Cd2+ and Zn2+. The ability of MpPCS to increase heavy metal resistance in yeast and to complement cad1-3 (the null mutant of the Arabidopsis ortholog AtPCS1) proves its function as the only PCS from M. polymorpha. Site-directed mutagenesis of the most conserved cysteines of the C-terminus of the enzyme further uncovered that two twin-cysteine motifs repress, to different extents, enzyme activation by heavy metal exposure. These results highlight an ancestral function of the PCS elusive C-terminus as a regulatory domain inhibiting enzyme overactivation by essential and non-essential heavy metals. The latter finding may be relevant for obtaining crops with decreased root to shoot mobility of cadmium, thus preventing its accumulation in the food chain.
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Affiliation(s)
- Mingai Li
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige, Trento, Italy
| | - Enrico Barbaro
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige, Trento, Italy
| | - Erika Bellini
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
| | - Alessandro Saba
- Dipartimento di Patologia Chirurgica, Medica, Molecolare e dell’Area Critica, Università di Pisa, Pisa, Italy
| | | | - Claudio Varotto
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige, Trento, Italy
- Correspondence: ,
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Dvorak M, Schnegg R, Niederwanger M, Pedrini-Martha V, Ladurner P, Lindner H, Kremser L, Lackner R, Dallinger R. Cadmium Pathways in Snails Follow a Complementary Strategy between Metallothionein Detoxification and Auxiliary Inactivation by Phytochelatins. Int J Mol Sci 2019; 21:ijms21010007. [PMID: 31861343 PMCID: PMC6981842 DOI: 10.3390/ijms21010007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/02/2019] [Accepted: 12/14/2019] [Indexed: 11/16/2022] Open
Abstract
Metal detoxification is crucial for animals to cope with environmental exposure. In snails, a pivotal role in protection against cadmium (Cd) is attributed to metallothioneins (MTs). Some gastropod species express, in a lineage-specific manner, Cd-selective MTs devoted exclusively to the binding and detoxification of this single metal, whereas other species of snails possess non-selective MTs, but still show a high tolerance against Cd. An explanation for this may be that invertebrates and in particular snails may also synthetize phytochelatins (PCs), originally known to be produced by plants, to provide protection against metal or metalloid toxicity. Here we demonstrate that despite the fact that similar mechanisms for Cd inactivation exist in snail species through binding of the metal to MTs, the actual detoxification pathways for this metal may follow different traits in a species-specific manner. In particular, this depends on the detoxification capacity of MTs due to their Cd-selective or non-specific binding features. In the terrestrial slug Arion vulgaris, for example, Cd is solely detoxified by a Cd-selective MT isoform (AvMT1). In contrast, the freshwater snail Biomphalaria glabrata activates an additional pathway for metal inactivation by synthesizing phytochelatins, which compensate for the insufficient capacity of its non-selective MT system to detoxify Cd. We hypothesize that in other snails and invertebrate species, too, an alternative inactivation of the metal by PCs may occur, if their MT system is not Cd-selective enough, or its Cd loading capacity is exhausted.
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Affiliation(s)
- Martin Dvorak
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Raimund Schnegg
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Michael Niederwanger
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Veronika Pedrini-Martha
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Peter Ladurner
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Herbert Lindner
- Institute of Clinical Biochemistry, Innsbruck Medical University, Biocenter, Innrain 80, A-6020 Innsbruck, Austria
| | - Leopold Kremser
- Institute of Clinical Biochemistry, Innsbruck Medical University, Biocenter, Innrain 80, A-6020 Innsbruck, Austria
| | - Reinhard Lackner
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
- Correspondence: (R.L.); (R.D.)
| | - Reinhard Dallinger
- Institute of Zoology and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
- Correspondence: (R.L.); (R.D.)
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10
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Raab A, Feldmann J. Biological sulphur-containing compounds – Analytical challenges. Anal Chim Acta 2019; 1079:20-29. [DOI: 10.1016/j.aca.2019.05.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 05/25/2019] [Accepted: 05/27/2019] [Indexed: 01/19/2023]
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11
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Li M, Stragliati L, Bellini E, Ricci A, Saba A, Sanità di Toppi L, Varotto C. Evolution and functional differentiation of recently diverged phytochelatin synthase genes from Arundo donax L. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5391-5405. [PMID: 31145784 PMCID: PMC6793451 DOI: 10.1093/jxb/erz266] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 05/24/2019] [Indexed: 05/15/2023]
Abstract
Phytochelatin synthases (PCSs) play pivotal roles in the detoxification of heavy metals and metalloids in plants; however, little information on the evolution of recently duplicated PCS genes in plant species is available. Here we characterize the evolution and functional differentiation of three PCS genes from the giant reed (Arundo donax L.), a biomass/bioenergy crop with remarkable resistance to cadmium and other heavy metals. Phylogenetic reconstruction with PCS genes from fully sequenced monocotyledonous genomes indicated that the three A. donax PCSs, namely AdPCS1-3, form a monophyletic clade. The AdPCS1-3 genes were expressed at low levels in many A. donax organs and displayed different levels of cadmium-responsive expression in roots. Overexpression of AdPCS1-3 in Arabidopsis thaliana and yeast reproduced the phenotype of functional PCS genes. Mass spectrometry analyses confirmed that AdPCS1-3 are all functional enzymes, but with significant differences in the amount of the phytochelatins synthesized. Moreover, heterogeneous evolutionary rates characterized the AdPCS1-3 genes, indicative of relaxed natural selection. These results highlight the elevated functional differentiation of A. donax PCS genes from both a transcriptional and an enzymatic point of view, providing evidence of the high evolvability of PCS genes and of plant responsiveness to heavy metal stress.
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Affiliation(s)
- Mingai Li
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige (TN) , Italy
| | - Luca Stragliati
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università degli studi di Parma, Parco Area delle Scienze, Parma, Italy
| | - Erika Bellini
- Dipartimento di Biologia, Università di Pisa, Pisa, Italy
| | - Ada Ricci
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università degli studi di Parma, Parco Area delle Scienze, Parma, Italy
| | - Alessandro Saba
- Dipartimento di Patologia Chirurgica, Medica, Molecolare e dell’Area Critica, Università di Pisa, Pisa, Italy
| | | | - Claudio Varotto
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige (TN) , Italy
- Correspondence: or
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12
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Chaudhuri P, Imam HT, Essig Y, Krasauskas J, Webb SM, Blindauer CA, Stürzenbaum SR. Molecular genetic and biochemical characterization of a putative family of zinc metalloproteins in Caenorhabditis elegans. Metallomics 2019; 10:1814-1823. [PMID: 30444224 PMCID: PMC6336089 DOI: 10.1039/c8mt00169c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The first characterization of W08E12.2, W08E12.3, W08E12.4 and W08E12.5, four putative metalloproteins in C. elegans. (A) phase contrast microscopy, (B) fluorescence microscopy of PW08E12.3;W08E12.4::GFP.
Four highly similar genes (W08E12.2, W08E12.3, W08E12.4 and W08E12.5) which are consecutively aligned on chromosome IV of the C. elegans genome are predicted to code for small (120–141aa) yet cysteine rich (18–19 cysteines) proteins. Cloning and sequencing of the genomic regions of the isoforms confirmed the presence and order of all genes. The generation of transgenic worms strains with an integrated single copy or extrachromosomal multi-copy PW08E12.3;W08E12.4::GFP uncovered that W08E12.3 and W08E12.4 are constitutively expressed in the pharynx and significantly induced in worms exposed to 100 μM Zn. Knockdown by RNAi did not have a marked consequence on reproductive performance nor was a Zn-dependent effect on nematode growth observed. However, RNAi of these genes led to an accumulation of Zn in the intestinal cells. W08E12.3 was recombinantly expressed in E. coli and the purified protein was shown to be able to bind up to 6.5 Zn molecules at neutral pH. Zn-binding was acid-labile and the apo protein was observed at pH < 4.3. This characterization suggests W08E12.2, W08E12.3, W08E12.4 and W08E12.5 belong to a family of putative Metalloproteins which, akin to metallothioneins, may play an important role in Zn-sensing, homeostasis and/or detoxification.
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Affiliation(s)
- Poulami Chaudhuri
- King's College London, School of Population Health & Environmental Sciences, Faculty of Life Sciences & Medicine, 150 Stamford Street, London, SE1 9NH, UK.
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Matern A, Böttcher C, Eschen-Lippold L, Westermann B, Smolka U, Döll S, Trempel F, Aryal B, Scheel D, Geisler M, Rosahl S. A substrate of the ABC transporter PEN3 stimulates bacterial flagellin (flg22)-induced callose deposition in Arabidopsis thaliana. J Biol Chem 2019; 294:6857-6870. [PMID: 30833326 DOI: 10.1074/jbc.ra119.007676] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 02/20/2019] [Indexed: 12/28/2022] Open
Abstract
Nonhost resistance of Arabidopsis thaliana against Phytophthora infestans, a filamentous eukaryotic microbe and the causal agent of potato late blight, is based on a multilayered defense system. Arabidopsis thaliana controls pathogen entry through the penetration-resistance genes PEN2 and PEN3, encoding an atypical myrosinase and an ABC transporter, respectively, required for synthesis and export of unknown indole compounds. To identify pathogen-elicited leaf surface metabolites and further unravel nonhost resistance in Arabidopsis, we performed untargeted metabolite profiling by incubating a P. infestans zoospore suspension on leaves of WT or pen3 mutant Arabidopsis plants. Among the plant-secreted metabolites, 4-methoxyindol-3-yl-methanol and S-(4-methoxy-indol-3-yl-methyl) cysteine were detected in spore suspensions recollected from WT plants, but at reduced levels from the pen3 mutant plants. In both whole-cell and microsome-based assays, 4-methoxyindol-3-yl-methanol was transported in a PEN3-dependent manner, suggesting that this compound is a PEN3 substrate. The syntheses of both compounds were dependent on functional PEN2 and phytochelatin synthase 1. None of these compounds inhibited mycelial growth of P. infestans in vitro Of note, exogenous application of 4-methoxyindol-3-yl methanol slightly elevated cytosolic Ca2+ levels and enhanced callose deposition in hydathodes of seedlings treated with a bacterial pathogen-associated molecular pattern (PAMP), flagellin (flg22). Loss of flg22-induced callose deposition in leaves of pen3 seedlings was partially reverted by the addition of 4-methoxyindol-3-yl methanol. In conclusion, we have identified a specific indole compound that is a substrate for PEN3 and contributes to the plant defense response against microbial pathogens.
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Affiliation(s)
- Andreas Matern
- From the Department of Stress and Developmental Biology and
| | | | | | - Bernhard Westermann
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany and
| | - Ulrike Smolka
- From the Department of Stress and Developmental Biology and
| | - Stefanie Döll
- From the Department of Stress and Developmental Biology and
| | - Fabian Trempel
- From the Department of Stress and Developmental Biology and
| | - Bibek Aryal
- the Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Dierk Scheel
- From the Department of Stress and Developmental Biology and
| | - Markus Geisler
- the Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Sabine Rosahl
- From the Department of Stress and Developmental Biology and
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14
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Filiz E, Saracoglu IA, Ozyigit II, Yalcin B. Comparative analyses of phytochelatin synthase (PCS) genes in higher plants. BIOTECHNOL BIOTEC EQ 2019. [DOI: 10.1080/13102818.2018.1559096] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Ertugrul Filiz
- Department of Crop and Animal Production, Cilimli Vocational School, Duzce University, Duzce, Turkey
| | | | - Ibrahim Ilker Ozyigit
- Department of Biology, Faculty of Science and Arts, Marmara University, Istanbul, Turkey
- Department of Biology, Faculty of Science, Kyrgyz-Turkish Manas University, Bishkek, Kyrgyzstan
| | - Bahattin Yalcin
- Department of Chemistry, Faculty of Science and Arts, Marmara University, Istanbul, Turkey
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15
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Haegerbaeumer A, Höss S, Heininger P, Traunspurger W. Is Caenorhabditis elegans representative of freshwater nematode species in toxicity testing? ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:2879-2888. [PMID: 29143265 DOI: 10.1007/s11356-017-0714-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 11/07/2017] [Indexed: 05/19/2023]
Abstract
Multi-species toxicity tests were conducted using a broad range of freshwater nematode species to assess interspecific differences in sensitivity to chemical stress and to compare the toxicity to that on the standard test organism Caenorhabditis elegans. The lethal effects of nine different chemical treatments, including metals and polycyclic aromatic hydrocarbons (PAHs) in single and mixture application, were determined for nematodes exposed for 48 h to spiked aqueous solutions. The investigated freshwater nematodes exhibited distinct differences in their sensitivity. Ranking of the susceptibility of 27 species to chemical stress showed that the effects were largely independent of the tested chemical compounds. Overall, the responses of C. elegans were well within the range of those of freshwater nematode species, being slightly less tolerant to metals, but more tolerant to PAHs than the average freshwater species response. Therefore, this study justified the use of C. elegans as representative model for freshwater nematode species in toxicity testing.
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Affiliation(s)
- Arne Haegerbaeumer
- Department of Animal Ecology, Bielefeld University, Konsequenz 45, 33615, Bielefeld, Germany.
| | - Sebastian Höss
- Department of Animal Ecology, Bielefeld University, Konsequenz 45, 33615, Bielefeld, Germany
- Ecossa, Giselastr. 6, 82319, Starnberg, Germany
| | - Peter Heininger
- German Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, 56068, Koblenz, Germany
| | - Walter Traunspurger
- Department of Animal Ecology, Bielefeld University, Konsequenz 45, 33615, Bielefeld, Germany
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16
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Cadmium effects on DNA and protein metabolism in oyster (Crassostrea gigas) revealed by proteomic analyses. Sci Rep 2017; 7:11716. [PMID: 28916745 PMCID: PMC5601910 DOI: 10.1038/s41598-017-11894-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 08/31/2017] [Indexed: 12/15/2022] Open
Abstract
Marine molluscs, including oysters, can concentrate high levels of cadmium (Cd) in their soft tissues, but the molecular mechanisms of Cd toxicity remain speculative. In this study, Pacific oysters (Crassostrea gigas) were exposed to Cd for 9 days and their gills were subjected to proteomic analysis, which were further confirmed with transcriptomic analysis. A total of 4,964 proteins was quantified and 515 differentially expressed proteins were identified in response to Cd exposure. Gene Ontology enrichment analysis revealed that excess Cd affected the DNA and protein metabolism. Specifically, Cd toxicity resulted in the inhibition of DNA glycosylase and gap-filling and ligation enzymes expressions in base excision repair pathway, which may have decreased DNA repair capacity. At the protein level, Cd induced the heat shock protein response, initiation of protein refolding as well as degradation by ubiquitin proteasome pathway, among other effects. Excess Cd also induced antioxidant responses, particularly glutathione metabolism, which play important roles in Cd chelation and anti-oxidation. This study provided the first molecular mechanisms of Cd toxicity on DNA and protein metabolism at protein levels, and identified molecular biomarkers for Cd toxicity in oysters.
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Sf G, Sk D, Bennett M, Raab A, Feldmann J, Kille P, Loureiro S, Dj S, Jg B. Sub-lethal cadmium exposure increases phytochelatin concentrations in the aquatic snail Lymnaea stagnalis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 568:1054-1058. [PMID: 27358197 DOI: 10.1016/j.scitotenv.2016.06.149] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/19/2016] [Accepted: 06/19/2016] [Indexed: 06/06/2023]
Abstract
Phytochelatins are metal-binding metabolites found in almost all plant species and some animal groups, including nematodes and annelids, where they can play an important role in detoxifying metals such as cadmium. Species from several other taxa contain a phytochelatin synthase (PCS) gene orthologue, including molluscs, indicating they may have the potential to synthesize phytochelatins. However, the presence of a gene alone does not demonstrate that it plays a functional role in metal detoxification. In the present study, we show that the aquatic snail Lymnaea stagnalis produced both penta- and heptapeptide phytochelatins (i.e. phytochelatin-2 and phytochelatin-3), and their levels increased in response to sub-lethal levels of cadmium.
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Affiliation(s)
- Gonçalves Sf
- Department of Biology & CESAM, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Davies Sk
- Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK
| | - M Bennett
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK
| | - A Raab
- TESLA, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, UK
| | - J Feldmann
- TESLA, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, UK
| | - P Kille
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
| | - S Loureiro
- Department of Biology & CESAM, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Spurgeon Dj
- Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Wallingford OX10 8BB, UK
| | - Bundy Jg
- Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK.
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18
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Essig YJ, Webb SM, Stürzenbaum SR. Deletion of Phytochelatin Synthase Modulates the Metal Accumulation Pattern of Cadmium Exposed C. elegans. Int J Mol Sci 2016; 17:257. [PMID: 26907254 PMCID: PMC4783986 DOI: 10.3390/ijms17020257] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/04/2016] [Accepted: 02/14/2016] [Indexed: 01/28/2023] Open
Abstract
Environmental metal pollution is a growing health risk to flora and fauna. It is therefore important to fully elucidate metal detoxification pathways. Phytochelatin synthase (PCS), an enzyme involved in the biosynthesis of phytochelatins (PCs), plays an important role in cadmium detoxification. The PCS and PCs are however not restricted to plants, but are also present in some lower metazoans. The model nematode Caenorhabditis elegans, for example, contains a fully functional phytochelatin synthase and phytochelatin pathway. By means of a transgenic nematode strain expressing a pcs-1 promoter-tagged GFP (pcs-1::GFP) and a pcs-1 specific qPCR assay, further evidence is presented that the expression of the C. elegans phytochelatin synthase gene (pcs-1) is transcriptionally non-responsive to a chronic (48 h) insult of high levels of zinc (500 μM) or acute (3 h) exposures to high levels of cadmium (300 μM). However, the accumulation of cadmium, but not zinc, is dependent on the pcs-1 status of the nematode. Synchrotron based X-ray fluorescence imaging uncovered that the cadmium body burden increased significantly in the pcs-1(tm1748) knockout allele. Taken together, this suggests that whilst the transcription of pcs-1 may not be mediated by an exposure zinc or cadmium, it is nevertheless an integral part of the cadmium detoxification pathway in C. elegans.
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Affiliation(s)
- Yona J Essig
- Analytical and Environmental Sciences Division, Faculty of Life Sciences & Medicine, King's College London, London SE1 9NH, UK.
- Medical Research Council-Public Health England (MRC-PHE) Centre for Environment & Health, King's College London, London SE1 9NH, UK.
| | - Samuel M Webb
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.
| | - Stephen R Stürzenbaum
- Analytical and Environmental Sciences Division, Faculty of Life Sciences & Medicine, King's College London, London SE1 9NH, UK.
- Medical Research Council-Public Health England (MRC-PHE) Centre for Environment & Health, King's College London, London SE1 9NH, UK.
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19
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Kühnlenz T, Westphal L, Schmidt H, Scheel D, Clemens S. Expression of Caenorhabditis elegans PCS in the AtPCS1-deficient Arabidopsis thaliana cad1-3 mutant separates the metal tolerance and non-host resistance functions of phytochelatin synthases. PLANT, CELL & ENVIRONMENT 2015; 38:2239-47. [PMID: 25764348 DOI: 10.1111/pce.12534] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 02/19/2015] [Accepted: 03/06/2015] [Indexed: 05/22/2023]
Abstract
Phytochelatin synthases (PCS) play key roles in plant metal tolerance. They synthesize small metal-binding peptides, phytochelatins, under conditions of metal excess. Respective mutants are strongly cadmium and arsenic hypersensitive. However, their ubiquitous presence and constitutive expression had long suggested a more general function of PCS besides metal detoxification. Indeed, phytochelatin synthase1 from Arabidopsis thaliana (AtPCS1) was later implicated in non-host resistance. The two different physiological functions may be attributable to the two distinct catalytic activities demonstrated for AtPCS1, that is the dipeptidyl transfer onto an acceptor molecule in phytochelatin synthesis, and the proteolytic deglycylation of glutathione conjugates. In order to test this hypothesis and to possibly separate the two biological roles, we expressed a phylogenetically distant PCS from Caenorhabditis elegans in an AtPCS1 mutant. We confirmed the involvement of AtPCS1 in non-host resistance by showing that plants lacking the functional gene develop a strong cell death phenotype when inoculated with the potato pathogen Phytophthora infestans. Furthermore, we found that the C. elegans gene rescues phytochelatin synthesis and cadmium tolerance, but not the defect in non-host resistance. This strongly suggests that the second enzymatic function of AtPCS1, which remains to be defined in detail, is underlying the plant immunity function.
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Affiliation(s)
- Tanja Kühnlenz
- Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, Bayreuth, 95440, Germany
| | - Lore Westphal
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, Halle, 06120, Germany
| | - Holger Schmidt
- Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, Bayreuth, 95440, Germany
| | - Dierk Scheel
- Department of Stress and Developmental Biology, Leibniz Institute of Plant Biochemistry, Weinberg 3, Halle, 06120, Germany
| | - Stephan Clemens
- Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, Bayreuth, 95440, Germany
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20
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Kumar R, Pradhan A, Khan FA, Lindström P, Ragnvaldsson D, Ivarsson P, Olsson PE, Jass J. Comparative Analysis of Stress Induced Gene Expression in Caenorhabditis elegans following Exposure to Environmental and Lab Reconstituted Complex Metal Mixture. PLoS One 2015; 10:e0132896. [PMID: 26168046 PMCID: PMC4500601 DOI: 10.1371/journal.pone.0132896] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 06/22/2015] [Indexed: 02/04/2023] Open
Abstract
Metals are essential for many physiological processes and are ubiquitously present in the environment. However, high metal concentrations can be harmful to organisms and lead to physiological stress and diseases. The accumulation of transition metals in the environment due to either natural processes or anthropogenic activities such as mining results in the contamination of water and soil environments. The present study used Caenorhabditis elegans to evaluate gene expression as an indicator of physiological response, following exposure to water collected from three different locations downstream of a Swedish mining site and a lab reconstituted metal mixture. Our results indicated that the reconstituted metal mixture exerted a direct stress response in C. elegans whereas the environmental waters elicited either a diminished or abrogated response. This suggests that it is not sufficient to use the biological effects observed from laboratory mixtures to extrapolate the effects observed in complex aquatic environments and apply this to risk assessment and intervention.
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Affiliation(s)
- Ranjeet Kumar
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
| | - Ajay Pradhan
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
| | - Faisal Ahmad Khan
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
| | | | | | | | - Per-Erik Olsson
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
| | - Jana Jass
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
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21
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Brunetti P, Zanella L, De Paolis A, Di Litta D, Cecchetti V, Falasca G, Barbieri M, Altamura MM, Costantino P, Cardarelli M. Cadmium-inducible expression of the ABC-type transporter AtABCC3 increases phytochelatin-mediated cadmium tolerance in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:3815-29. [PMID: 25900618 PMCID: PMC4473984 DOI: 10.1093/jxb/erv185] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The heavy metal cadmium (Cd) is a widespread environmental contaminant with harmful effects on living cells. In plants, phytochelatin (PC)-dependent Cd detoxification requires that PC-Cd complexes are transported into vacuoles. Here, it is shown that Arabidopsis thaliana seedlings defective in the ABCC transporter AtABCC3 (abcc3) have an increased sensitivity to different Cd concentrations, and that seedlings overexpressing AtABCC3 (AtABCC3ox) have an increased Cd tolerance. The cellular distribution of Cd was analysed in protoplasts from abcc3 mutants and AtABCC3 overexpressors grown in the presence of Cd, by means of the Cd-specific fluorochromes 5-nitrobenzothiazole coumarin (BTC-5N) and Leadmium™ Green AM dye. This analysis revealed that Cd is mostly localized in the cytosol of abcc3 mutant protoplasts whereas there is an increase in vacuolar Cd in protoplasts from AtABCC3ox plants. Overexpression of AtABCC3 in cad1-3 mutant seedlings defective in PC production and in plants treated with l-buthionine sulphoximine (BSO), an inhibitor of PC biosynthesis, had no effect on Cd tolerance, suggesting that AtABCC3 acts via PCs. In addition, overexpression of AtABCC3 in atabcc1 atabcc2 mutant seedlings defective in the Cd transporters AtABCC1 and AtABCC2 complements the Cd sensitivity of double mutants, but not in the presence of BSO. Accordingly, the level of AtABCC3 transcript in wild type seedlings was lower than that of AtABCC1 and AtABCC2 in the absence of Cd but higher after Cd exposure, and even higher in atabcc1 atabcc2 mutants. The results point to AtABCC3 as a transporter of PC-Cd complexes, and suggest that its activity is regulated by Cd and is co-ordinated with the activity of AtABCC1/AtABCC2.
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Affiliation(s)
- Patrizia Brunetti
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Rome, Italy
| | - Letizia Zanella
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Rome, Italy
| | - Angelo De Paolis
- Istituto di Scienze delle Produzioni Alimentari, CNR, Lecce, Italy
| | - Davide Di Litta
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy
| | - Valentina Cecchetti
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Rome, Italy
| | - Giuseppina Falasca
- Dipartimento di Biologia Ambientale, Sapienza Università di Roma, Rome, Italy
| | - Maurizio Barbieri
- Dipartimento di Scienze della Terra, Sapienza Università di Roma, Rome, Italy
| | | | - Paolo Costantino
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Rome, Italy
| | - Maura Cardarelli
- Istituto di Biologia e Patologia Molecolari, CNR, Sapienza Università di Roma, Rome, Italy
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22
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Homa J, Rorat A, Kruk J, Cocquerelle C, Plytycz B, Vandenbulcke F. Dermal exposure of Eisenia andrei earthworms: Effects of heavy metals on metallothionein and phytochelatin synthase gene expressions in coelomocytes. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2015; 34:1397-1404. [PMID: 25693738 DOI: 10.1002/etc.2944] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/01/2014] [Accepted: 02/14/2015] [Indexed: 06/04/2023]
Abstract
Parameters such as total number of coelomocytes, riboflavin content in coelomocytes, expression of genes implied in metal homeostasis, and detoxification mechanisms can be used as biomarkers to assess the impact of metals on annelids. Defense biomarkers (detoxification gene expressions and coelomocyte parameters) were investigated in the ecotoxicologically important species Eisenia andrei following in vivo exposure to 5 different metals (zinc, copper, nickel, lead, and cadmium) at known concentrations. Coelomocyte numbers and riboflavin content were not affected by metallic exposure, but metal-specific gene expression variations were evidenced.
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Affiliation(s)
- Joanna Homa
- Department of Evolutionary Immunology, Institute of Zoology, Jagiellonian University, Kraków, Poland
| | - Agnieszka Rorat
- Institute of Environmental Engineering, Czestochowa University of Technology, Czestochowa, Poland
- Environmental Axis, Lille 1 University, Villeneuve d'Ascq, France
| | - Jerzy Kruk
- Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Kraków, Poland
| | | | - Barbara Plytycz
- Department of Evolutionary Immunology, Institute of Zoology, Jagiellonian University, Kraków, Poland
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23
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Bundy JG, Kille P. Metabolites and metals in Metazoa--what role do phytochelatins play in animals? Metallomics 2015; 6:1576-82. [PMID: 24926533 DOI: 10.1039/c4mt00078a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Phytochelatins are sulfur-rich metal-binding peptides, and phytochelatin synthesis is one of the key mechanisms by which plants protect themselves against toxic soft metal ions such as cadmium. It has been known for a while now that some invertebrates also possess functional phytochelatin synthase (PCS) enzymes, and that at least one species, the nematode Caenorhabditis elegans, produces phytochelatins to help detoxify cadmium, and probably also other metal and metalloid ions including arsenic, zinc, selenium, silver, and copper. Here, we review recent studies on the occurrence, utilization, and regulation of phytochelatin synthesis in invertebrates. The phytochelatin synthase gene has a wide phylogenetic distribution, and can be found in species that cover almost all of the animal tree of life. The evidence to date, though, suggests that the occurrence is patchy, and even though some members of particular taxonomic groups may contain PCS genes, there are also many species without these genes. For animal species that do possess PCS genes, some of them (e.g. earthworms) do synthesize phytochelatins in response to potentially toxic elements, whereas others (e.g. Schistosoma mansoni, a parasitic helminth) do not appear to do so. Just how (and if) phytochelatins in invertebrates complement the function of metallothioneins remains to be elucidated, and the temporal, spatial, and metal specificity of the two systems is still unknown.
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Affiliation(s)
- J G Bundy
- Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK.
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24
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Bougerol M, Boutet I, LeGuen D, Jollivet D, Tanguy A. Transcriptomic response of the hydrothermal mussel Bathymodiolus azoricus in experimental exposure to heavy metals is modulated by the Pgm genotype and symbiont content. Mar Genomics 2014; 21:63-73. [PMID: 25542630 DOI: 10.1016/j.margen.2014.11.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 11/28/2014] [Accepted: 11/28/2014] [Indexed: 11/27/2022]
Abstract
Hydrothermal vent mussels belonging to the genus Bathymodiolus dominate communities at hydrothermal sites of the Mid-Atlantic Ridge. The mussel Bathymodiolus azoricus harbors thiotrophic and methanotrophic symbiotic bacteria in its gills and evolves in naturally highly metal contaminated environments. In the context of investigations on metal tolerance/effect in B. azoricus, we focused our work on the short-term adaptive response (15days) of mussels to different metals exposure at a molecular level using metal concentrations chosen to mimic natural situations at three vents sites. The expression of a set of 38 genes involved in different steps of the metal uptake, detoxication and various metabolisms was analysed by qPCR. Mussels were also genotyped at 10 enzyme loci to explore the relationships among natural genetic variation and gene expression. Relation between symbiont content (both sulfur-oxidizing and methanogen bacteria) and gene expression was also analysed. Our study demonstrated the influence of metal cocktail composition and time exposure on the transcriptome regulation with a specific pattern of regulation observed for the three metal cocktail tested. We also evidenced the significant influence of some specific Pgm genotype on the global gene expression in our experimental populations and a general trend of a higher gene expression in individuals carrying a high symbiont content.
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Affiliation(s)
- Marion Bougerol
- CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, 29680 Roscoff, France; Sorbonne Universités, UPMC Univ Paris 06, Station Biologique de Roscoff, 29680 Roscoff, France; CNRS/MNHN, UMR 7221, Evolution des Régulations Endocriniennes, MNHN, 7 Rue Cuvier, 75231 Paris Cedex 05, France
| | - Isabelle Boutet
- CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, 29680 Roscoff, France; Sorbonne Universités, UPMC Univ Paris 06, Station Biologique de Roscoff, 29680 Roscoff, France
| | - Dominique LeGuen
- CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, 29680 Roscoff, France; Sorbonne Universités, UPMC Univ Paris 06, Station Biologique de Roscoff, 29680 Roscoff, France
| | - Didier Jollivet
- CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, 29680 Roscoff, France; Sorbonne Universités, UPMC Univ Paris 06, Station Biologique de Roscoff, 29680 Roscoff, France
| | - Arnaud Tanguy
- CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, 29680 Roscoff, France; Sorbonne Universités, UPMC Univ Paris 06, Station Biologique de Roscoff, 29680 Roscoff, France.
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Heterologous expression of Ceratophyllum demersum phytochelatin synthase, CdPCS1, in rice leads to lower arsenic accumulation in grain. Sci Rep 2014; 4:5784. [PMID: 25048298 PMCID: PMC4105706 DOI: 10.1038/srep05784] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/07/2014] [Indexed: 12/17/2022] Open
Abstract
Recent studies have identified rice (Oryza sativa) as a major dietary source of inorganic arsenic (As) and poses a significant human health risk. The predominant model for plant detoxification of heavy metals is complexation of heavy metals with phytochelatins (PCs), synthesized non-translationally by PC synthase (PCS) and compartmentalized in vacuoles. In this study, in order to restrict As in the rice roots as a detoxification mechanism, a transgenic approach has been followed through expression of phytochelatin synthase, CdPCS1, from Ceratophyllum demersum, an aquatic As-accumulator plant. CdPCS1 expressing rice transgenic lines showed marked increase in PCS activity and enhanced synthesis of PCs in comparison to non-transgenic plant. Transgenic lines showed enhanced accumulation of As in root and shoot. This enhanced metal accumulation potential of transgenic lines was positively correlated to the content of PCs, which also increased several-fold higher in transgenic lines. However, all the transgenic lines accumulated significantly lower As in grain and husk in comparison to non-transgenic plant. The higher level of PCs in transgenic plants relative to non-transgenic presumably allowed sequestering and detoxification of higher amounts of As in roots and shoots, thereby restricting its accumulation in grain.
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Franchi N, Piccinni E, Ferro D, Basso G, Spolaore B, Santovito G, Ballarin L. Characterization and transcription studies of a phytochelatin synthase gene from the solitary tunicate Ciona intestinalis exposed to cadmium. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 152:47-56. [PMID: 24727215 DOI: 10.1016/j.aquatox.2014.03.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 03/18/2014] [Accepted: 03/21/2014] [Indexed: 05/22/2023]
Abstract
The major thiol-containing molecules involved in controlling the level of intracellular ROS in eukaryotes, acting as a nonenzymatic detoxification system, are metallothioneins (MTs), glutathione (GSH) and phytochelatins (PCs). Both MTs and GSH are well-known in the animal kingdom. PC was considered a prerogative of the plant kingdom but, in 2001, a phytochelatin synthase (PCS) gene was described in the nematode Caenorhabditis elegans; additional genes encoding this enzyme were later described in the earthworm Eisenia fetida and in the parasitic nematode Schistosoma mansoni but scanty data are available, up to now, for Deuterostomes. Here, we describe the molecular characteristics and transcription pattern, in the presence of Cd, of a PCS gene from the invertebrate chordate Ciona intestinalis, a ubiquitous solitary tunicate and demonstrate the presence of PCs in tissue extracts. We also studied mRNA localization by in situ hybridization. In addition, we analyzed the behavior of hemocytes and tunic cells consequent to Cd exposure as well as the transcription pattern of the Ciona orthologous for proliferating cell nuclear antigen (PCNA), usually considered a proliferation marker, and observed that cell proliferation occurs after 96h of Cd treatment. This matches the hypothesis of Cd-induced cell proliferation, as already suggested by previous data on the expression of a metallothionein gene in the same animal.
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Affiliation(s)
- Nicola Franchi
- Department of Biology, University of Padova, Padova, Italy; Department of Biological, Chemical, Pharmaceutical Science and Technology, University of Palermo, Palermo, Italy
| | - Ester Piccinni
- Department of Biology, University of Padova, Padova, Italy
| | - Diana Ferro
- Department of Biology, University of Padova, Padova, Italy; Institute for Evolution and Biodiversity, Westfälische Wilhelms-Universität, Münster, Germany
| | - Giuseppe Basso
- Department of Woman and Child Health, University of Padova, Padova, Italy
| | - Barbara Spolaore
- CRIBI Biotechnology Centre, University of Padova, Padova, Italy; Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
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Koffler BE, Polanschütz L, Zechmann B. Higher sensitivity of pad2-1 and vtc2-1 mutants to cadmium is related to lower subcellular glutathione rather than ascorbate contents. PROTOPLASMA 2014; 251:755-69. [PMID: 24281833 PMCID: PMC4059996 DOI: 10.1007/s00709-013-0576-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 10/25/2013] [Indexed: 05/02/2023]
Abstract
Cadmium (Cd) interferes with ascorbate and glutathione metabolism as it induces the production of reactive oxygen species (ROS), binds to glutathione due to its high affinity to thiol groups, and induces the production of phytochelatins (PCs) which use glutathione as a precursor. In this study, changes in the compartment specific distribution of ascorbate and glutathione were monitored over a time period of 14 days in Cd-treated (50 and 100 μM) Arabidopsis Col-0 plants, and two mutant lines deficient in glutathione (pad2-1) and ascorbate (vtc2-1). Both mutants showed higher sensitivity to Cd than Col-0 plants. Strongly reduced compartment specific glutathione, rather than decreased ascorbate contents, could be correlated with the development of symptoms in these mutants suggesting that higher sensitivity to Cd is related to low glutathione contents rather than low ascorbate contents. On the subcellular level it became obvious that long-term treatment of wildtype plants with Cd induced the depletion of glutathione and ascorbate contents in all cell compartments except chloroplasts indicating an important protective role for antioxidants in chloroplasts against Cd. Additionally, we could observe an immediate decrease of glutathione and ascorbate in all cell compartments 12 h after Cd treatment indicating that glutathione and ascorbate are either withdrawn from or not redistributed into other organelles after their production in chloroplasts, cytosol (production centers for glutathione) and mitochondria (production center for ascorbate). The obtained data is discussed in respect to recently proposed stress models involving antioxidants in the protection of plants against environmental stress conditions.
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Affiliation(s)
- Barbara Eva Koffler
- Institute of Plant Sciences, University of Graz, Schubertstrasse 51, 8010 Graz, Austria
| | - Lisa Polanschütz
- Institute of Plant Sciences, University of Graz, Schubertstrasse 51, 8010 Graz, Austria
| | - Bernd Zechmann
- Institute of Plant Sciences, University of Graz, Schubertstrasse 51, 8010 Graz, Austria
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Wang Y, Xiao X, Zhang T, Kang H, Zeng J, Fan X, Sha L, Zhang H, Yu K, Zhou Y. Cadmium treatment alters the expression of five genes at the Cda1 locus in two soybean cultivars [Glycine max (L.) Merr]. ScientificWorldJournal 2014; 2014:979750. [PMID: 24987750 PMCID: PMC4060588 DOI: 10.1155/2014/979750] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 03/19/2014] [Accepted: 03/26/2014] [Indexed: 01/22/2023] Open
Abstract
Westag 97 has larger capacity of Cd accumulation in roots which prevents Cd from translocating into stems and leaves; conversely, AC Hime has smaller capacity of Cd accumulation in roots; more Cd is transported into stems and leaves. The different capacity of Cd in roots between Westag 97 and AC Hime causes the different Cd concentration in seeds. Meanwhile, according to the different expression levels of RSTK, ISCP, and H(+)-ATPase between Westag 97 and AC Hime, RSTK may be involved in transporting Cd into stems and leaves; H(+)-ATPase may be correlated to the capacity of Cd accumulation in roots; and Cd caused some changes of fundamental life process which leaded to the different expression patterns of ISCP between Westag 97 and AC Hime.
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Affiliation(s)
- Yi Wang
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
- Greenhouse and Processing Crops Research Centre, Agriculture and Agri-Food Canada, 2582 County Road 20, Harrow, ON, Canada N0R 1G0
| | - Xue Xiao
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
| | - Tiequan Zhang
- Greenhouse and Processing Crops Research Centre, Agriculture and Agri-Food Canada, 2582 County Road 20, Harrow, ON, Canada N0R 1G0
| | - Houyang Kang
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
| | - Jian Zeng
- College of Resources and Environment, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
| | - Xing Fan
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
| | - Lina Sha
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
| | - Haiqin Zhang
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
| | - Kangfu Yu
- Greenhouse and Processing Crops Research Centre, Agriculture and Agri-Food Canada, 2582 County Road 20, Harrow, ON, Canada N0R 1G0
| | - Yonghong Zhou
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130, China
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Song WY, Mendoza-Cózatl DG, Lee Y, Schroeder JI, Ahn SN, Lee HS, Wicker T, Martinoia E. Phytochelatin-metal(loid) transport into vacuoles shows different substrate preferences in barley and Arabidopsis. PLANT, CELL & ENVIRONMENT 2014; 37:1192-201. [PMID: 24313707 PMCID: PMC4123957 DOI: 10.1111/pce.12227] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/16/2013] [Accepted: 10/21/2013] [Indexed: 05/18/2023]
Abstract
Cadmium (Cd) and arsenic (As) are toxic to all living organisms, including plants and humans. In plants, Cd and As are detoxified by phytochelatins (PCs) and metal(loid)-chelating peptides and by sequestering PC-metal(loid) complexes in vacuoles. Consistent differences have been observed between As and Cd detoxification. Whereas chelation of Cd by PCs is largely sufficient to detoxify Cd, As-PC complexes must be sequestered into vacuoles to be fully detoxified. It is not clear whether this difference in detoxification pathways is ubiquitous among plants or varies across species. Here, we have conducted a PC transport study using vacuoles isolated from Arabidopsis and barley. Arabidopsis vacuoles accumulated low levels of PC2 -Cd, and vesicles from yeast cells expressing either AtABCC1 or AtABCC2 exhibited negligible PC2 -Cd transport activity compared with PC2 -As. In contrast, barley vacuoles readily accumulated comparable levels of PC2 -Cd and PC2 -As. PC transport in barley vacuoles was inhibited by vanadate, but not by ammonium, suggesting the involvement of ABC-type transporters. Interestingly, barley vacuoles exhibited enhanced PC2 transport activity when essential metal ions, such as Zn(II), Cu(II) and Mn(II), were added to the transport assay, suggesting that PCs might contribute to the homeostasis of essential metals and detoxification of non-essential toxic metal(loid)s.
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Affiliation(s)
- Won-Yong Song
- POSTECH-UZH Cooperative Laboratory, Department of Integrative Bioscience and Biotechnology, Pohang University of Science and Technology, Pohang, 790-784, Korea
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Petraglia A, De Benedictis M, Degola F, Pastore G, Calcagno M, Ruotolo R, Mengoni A, Sanità di Toppi L. The capability to synthesize phytochelatins and the presence of constitutive and functional phytochelatin synthases are ancestral (plesiomorphic) characters for basal land plants. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1153-63. [PMID: 24449382 DOI: 10.1093/jxb/ert472] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Bryophytes, a paraphyletic group which includes liverworts, mosses, and hornworts, have been stated as land plants that under metal stress (particularly cadmium) do not synthesize metal-binding peptides such as phytochelatins. Moreover, very little information is available to date regarding phytochelatin synthesis in charophytes, postulated to be the direct ancestors of land plants, or in lycophytes, namely very basal tracheophytes. In this study, it was hypothesized that basal land plants and charophytes have the capability to produce phytochelatins and possess constitutive and functional phytochelatin synthases. To verify this hypothesis, twelve bryophyte species (six liverworts, four mosses, and two hornworts), three charophytes, and two lycophyte species were exposed to 0-36 μM cadmium for 72 h, and then assayed for: (i) glutathione and phytochelatin quali-quantitative content by HPLC and mass spectrometry; (ii) the presence of putative phytochelatin synthases by western blotting; and (iii) in vitro activity of phytochelatin synthases. Of all the species tested, ten produced phytochelatins in vivo, while the other seven did not. The presence of a constitutively expressed and functional phytochelatin synthase was demonstrated in all the bryophyte lineages and in the lycophyte Selaginella denticulata, but not in the charophytes. Hence, current knowledge according to phytochelatins have been stated as being absent in bryophytes was therefore confuted by this work. It is argued that the capability to synthesize phytochelatins, as well as the presence of active phytochelatin synthases, are ancestral (plesiomorphic) characters for basal land plants.
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Affiliation(s)
- Alessandro Petraglia
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/A, I-43124 Parma, Italy
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Danh LT, Truong P, Mammucari R, Foster N. A critical review of the arsenic uptake mechanisms and phytoremediation potential of Pteris vittata. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2014; 16:429-53. [PMID: 24912227 DOI: 10.1080/15226514.2013.798613] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The discovery of the arsenic hyperaccumulator, Pteris vittata (Chinese brake fern), has contributed to the promotion of its application as a means of phytoremediation for arsenic removal from contaminated soils and water. Understanding the mechanisms involved in arsenic tolerance and accumulation of this plant provides valuable tools to improve the phytoremediation efficiency. In this review, the current knowledge about the physiological and molecular mechanisms of arsenic tolerance and accumulation in P. vittata is summarized, and an attempt has been made to clarify some of the unresolved questions related to these mechanisms. In addition, the capacity of P. vittata for remediation of arsenic-contaminated soils is evaluated under field conditions for the first time, and possible solutions to improve the remediation capacity of Pteris vittata are also discussed.
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Liebeke M, Garcia-Perez I, Anderson CJ, Lawlor AJ, Bennett MH, Morris CA, Kille P, Svendsen C, Spurgeon DJ, Bundy JG. Earthworms produce phytochelatins in response to arsenic. PLoS One 2013; 8:e81271. [PMID: 24278409 PMCID: PMC3838358 DOI: 10.1371/journal.pone.0081271] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 10/10/2013] [Indexed: 12/13/2022] Open
Abstract
Phytochelatins are small cysteine-rich non-ribosomal peptides that chelate soft metal and metalloid ions, such as cadmium and arsenic. They are widely produced by plants and microbes; phytochelatin synthase genes are also present in animal species from several different phyla, but there is still little known about whether these genes are functional in animals, and if so, whether they are metal-responsive. We analysed phytochelatin production by direct chemical analysis in Lumbricus rubellus earthworms exposed to arsenic for a 28 day period, and found that arsenic clearly induced phytochelatin production in a dose-dependent manner. It was necessary to measure the phytochelatin metabolite concentrations directly, as there was no upregulation of phytochelatin synthase gene expression after 28 days: phytochelatin synthesis appears not to be transcriptionally regulated in animals. A further untargetted metabolomic analysis also found changes in metabolites associated with the transsulfuration pathway, which channels sulfur flux from methionine for phytochelatin synthesis. There was no evidence of biological transformation of arsenic (e.g. into methylated species) as a result of laboratory arsenic exposure. Finally, we compared wild populations of earthworms sampled from the field, and found that both arsenic-contaminated and cadmium-contaminated mine site worms had elevated phytochelatin concentrations.
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Affiliation(s)
- Manuel Liebeke
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Isabel Garcia-Perez
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Craig J. Anderson
- Centre for Ecology and Hydrology, Wallingford, United Kingdom
- School of Biosciences, University of Cardiff, Cardiff, United Kingdom
| | - Alan J. Lawlor
- Centre for Ecology and Hydrology, Lancaster, United Kingdom
| | - Mark H. Bennett
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Ceri A. Morris
- School of Biosciences, University of Cardiff, Cardiff, United Kingdom
| | - Peter Kille
- School of Biosciences, University of Cardiff, Cardiff, United Kingdom
| | - Claus Svendsen
- Centre for Ecology and Hydrology, Wallingford, United Kingdom
| | | | - Jacob G. Bundy
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
- * E-mail:
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Vozdek R, Hnízda A, Krijt J, Será L, Kožich V. Biochemical properties of nematode O-acetylserine(thiol)lyase paralogs imply their distinct roles in hydrogen sulfide homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2691-701. [PMID: 24100226 DOI: 10.1016/j.bbapap.2013.09.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 09/23/2013] [Accepted: 09/25/2013] [Indexed: 01/08/2023]
Abstract
O-Acetylserine(thiol)lyases (OAS-TLs) play a pivotal role in a sulfur assimilation pathway incorporating sulfide into amino acids in microorganisms and plants, however, these enzymes have not been found in the animal kingdom. Interestingly, the genome of the roundworm Caenorhabditis elegans contains three expressed genes predicted to encode OAS-TL orthologs (cysl-1-cysl-3), and a related pseudogene (cysl-4); these genes play different roles in resistance to hypoxia, hydrogen sulfide and cyanide. To get an insight into the underlying molecular mechanisms we purified the three recombinant worm OAS-TL proteins, and we determined their enzymatic activities, substrate binding affinities, quaternary structures and the conformations of their active site shapes. We show that the nematode OAS-TL orthologs can bind O-acetylserine and catalyze the canonical reaction although this ligand may more likely serve as a competitive inhibitor to natural substrates instead of being a substrate for sulfur assimilation. In addition, we propose that S-sulfocysteine may be a novel endogenous substrate for these proteins. However, we observed that the three OAS-TL proteins are conformationally different and exhibit distinct substrate specificity. Based on the available evidences we propose the following model: CYSL-1 interacts with EGL-9 and activates HIF-1 that upregulates expression of genes detoxifying sulfide and cyanide, the CYSL-2 acts as a cyanoalanine synthase in the cyanide detoxification pathway and simultaneously produces hydrogen sulfide, while the role of CYSL-3 remains unclear although it exhibits sulfhydrylase activity in vitro. All these data indicate that C. elegans OAS-TL paralogs have distinct cellular functions and may play different roles in maintaining hydrogen sulfide homeostasis.
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Affiliation(s)
- Roman Vozdek
- Institute of Inherited Metabolic Disorders, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 2, Prague 2, 128 08, Czech Republic
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Rigouin C, Vermeire JJ, Nylin E, Williams DL. Characterization of the phytochelatin synthase from the human parasitic nematode Ancylostoma ceylanicum. Mol Biochem Parasitol 2013; 191:1-6. [PMID: 23916800 PMCID: PMC3823645 DOI: 10.1016/j.molbiopara.2013.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/18/2013] [Accepted: 07/19/2013] [Indexed: 11/21/2022]
Abstract
Hookworm disease is a debilitating worm infection that affects hundreds of millions of people. Despite the existence of anthelmintic drugs, reports have testified of a decrease in efficacy of these drugs. Therefore, it is imperative to find new drugs and drug targets for hookworm disease treatment. In this study we identify the gene encoding the phytochelatin synthase in the human hookworm, Ancylostoma ceylanicum (AcePCS). Phytochelatin synthase catalyzes the production of metal chelating peptides, the phytochelatins, from glutathione (GSH). In plants, algae, and fungi phytochelatin production is important for metal tolerance and detoxification. Phytochelatin synthase proteins also function in the elimination of xenobiotics by processing GSH S-conjugates. We found that in vitro AcePCS could both synthesize phytochelatins and hydrolyze a GSH S-conjugate. Interestingly, the enzyme works through a thiol-dependent and, notably, metal-independent mechanism for both transpeptidase (phytochelatin synthesis) and peptidase (hydrolysis of GSH S-conjugates) activities. AcePCS mRNAs are expressed in vivo throughout the life cycle of A. ceylanicum. Mature adult male hookworms isolated from the small intestines of their hosts displayed significantly enhanced expression of AcePCS with transcript levels 5-fold greater than other developmental forms. Although the role of AcePCS in A. ceylanicum biology has yet to be fully investigated the results reported here provide encouraging evidence of the potential that this enzyme holds as a target for new chemotherapeutic intervention.
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Affiliation(s)
- Coraline Rigouin
- Department of Immunology/Microbiology, Rush University Medical Center, 1735 West Harrison Street, Chicago, IL 60612, United States
| | - Jon J. Vermeire
- Program in International Child Health and Department of Pediatrics, Yale University School of Medicine, New Haven, CT, United States
| | - Elyse Nylin
- Department of Immunology/Microbiology, Rush University Medical Center, 1735 West Harrison Street, Chicago, IL 60612, United States
| | - David L. Williams
- Department of Immunology/Microbiology, Rush University Medical Center, 1735 West Harrison Street, Chicago, IL 60612, United States
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Preston JC, Hileman LC. Functional Evolution in the Plant SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) Gene Family. FRONTIERS IN PLANT SCIENCE 2013; 4:80. [PMID: 23577017 PMCID: PMC3617394 DOI: 10.3389/fpls.2013.00080] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 03/19/2013] [Indexed: 05/18/2023]
Abstract
The SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) family of transcription factors is functionally diverse, controlling a number of fundamental aspects of plant growth and development, including vegetative phase change, flowering time, branching, and leaf initiation rate. In natural plant populations, variation in flowering time and shoot architecture have major consequences for fitness. Likewise, in crop species, variation in branching and developmental rate impact biomass and yield. Thus, studies aimed at dissecting how the various functions are partitioned among different SPL genes in diverse plant lineages are key to providing insight into the genetic basis of local adaptation and have already garnered attention by crop breeders. Here we use phylogenetic reconstruction to reveal nine major SPL gene lineages, each of which is described in terms of function and diversification. To assess evidence for ancestral and derived functions within each SPL gene lineage, we use ancestral character state reconstructions. Our analyses suggest an emerging pattern of sub-functionalization, neo-functionalization, and possible convergent evolution following both ancient and recent gene duplication. Based on these analyses we suggest future avenues of research that may prove fruitful for elucidating the importance of SPL gene evolution in plant growth and development.
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Affiliation(s)
| | - Lena C. Hileman
- Ecology and Evolutionary Biology, The University of KansasLawrence, KS, USA
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Rigouin C, Nylin E, Cogswell AA, Schaumlöffel D, Dobritzsch D, Williams DL. Towards an understanding of the function of the phytochelatin synthase of Schistosoma mansoni. PLoS Negl Trop Dis 2013; 7:e2037. [PMID: 23383357 PMCID: PMC3561135 DOI: 10.1371/journal.pntd.0002037] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/13/2012] [Indexed: 11/19/2022] Open
Abstract
Phytochelatin synthase (PCS) is a protease-like enzyme that catalyzes the production of metal chelating peptides, the phytochelatins, from glutathione (GSH). In plants, algae, and fungi phytochelatin production is important for metal tolerance and detoxification. PCS proteins also function in xenobiotic metabolism by processing GSH S-conjugates. The aim of the present study is to elucidate the role of PCS in the parasitic worm Schistosoma mansoni. Recombinant S. mansoni PCS proteins expressed in bacteria could both synthesize phytochelatins and hydrolyze various GSH S-conjugates. We found that both the N-truncated protein and the N- and C-terminal truncated form of the enzyme (corresponding to only the catalytic domain) work through a thiol-dependant and, notably, metal-independent mechanism for both transpeptidase (phytochelatin synthesis) and peptidase (hydrolysis of GSH S-conjugates) activities. PCS transcript abundance was increased by metals and xenobiotics in cultured adult worms. In addition, these treatments were found to increase transcript abundance of other enzymes involved in GSH metabolism. Highest levels of PCS transcripts were identified in the esophageal gland of adult worms. Taken together, these results suggest that S. mansoni PCS participates in both metal homoeostasis and xenobiotic metabolism rather than metal detoxification as previously suggested and that the enzyme may be part of a global stress response in the worm. Because humans do not have PCS, this enzyme is of particular interest as a drug target for schistosomiasis. Schistosomiasis is a chronic, debilitating disease that affects hundreds of millions of people. The treatment of schistosomiasis relies solely on monotherapy with praziquantel and there is concern that drug-resistant parasites will evolve. Therefore, it is imperative to identify new drugs for schistosomiasis treatment. In this study our goal was to characterize the function of the phytochelatin synthase of Schistosoma mansoni, previously suggested as a candidate for drug targeting to control schistosomiasis. Phytochelatin synthase catalyzes the production of metal chelating peptides, the phytochelatins, from glutathione (GSH). In plants, algae, and fungi phytochelatin production is important for metal tolerance and detoxification. PCS proteins also function in the elimination of xenobiotics by processing GSH S-conjugates. We found that SmPCS expressed in bacteria could both synthesize phytochelatins and hydrolyze various GSH S-conjugates. We found the enzyme works through a thiol-dependant and, notably, metal-independent mechanism for both transpeptidase (phytochelatin synthesis) and peptidase (hydrolysis of GSH S-conjugates) activities. The expression of the PCS gene in adult schistosome worms was increased by exposure to a number of metals and xenobiotics. In addition, these treatments were found to increase the expression of other enzymes involved in GSH metabolism. Highest levels of PCS transcripts were localized in the esophageal gland of adult worms. Taken together, these results suggest that S. mansoni PCS participates in both metal homoeostasis and xenobiotic metabolism rather than metal detoxification as previously suggested and that it may be part of a global stress response in the worm.
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Affiliation(s)
- Coraline Rigouin
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Elyse Nylin
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Alexis A. Cogswell
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Dirk Schaumlöffel
- Université de Pau et des Pays de l'Adour/CNRS UMR 5254, Laboratoire de Chimie Analytique Bio-Inorganique et Environnement/IPREM, Hélioparc, Pau, France
| | - Dirk Dobritzsch
- Martin-Luther-Universität Halle-Wittenberg, Institut für Biochemie und Biotechnologie, Abteilung Pflanzenbiochemie, Halle, Saale, Germany
| | - David L. Williams
- Department of Immunology/Microbiology, Rush University Medical Center, Chicago, Illinois, United States of America
- * E-mail:
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Wan X, Freisinger E. Incorporation of Sulfide Ions into the Cadmium(II) Thiolate Cluster of Cicer arietinum Metallothionein2. Inorg Chem 2012; 52:785-92. [DOI: 10.1021/ic301907j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xiaoqiong Wan
- Institute of Inorganic
Chemistry, University of Zurich, 8057 Zurich, Switzerland
- Key Laboratory of Arable Land
Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Eva Freisinger
- Institute of Inorganic
Chemistry, University of Zurich, 8057 Zurich, Switzerland
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38
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Irfan M, Hayat S, Ahmad A, Alyemeni MN. Soil cadmium enrichment: Allocation and plant physiological manifestations. Saudi J Biol Sci 2012; 20:1-10. [PMID: 23961213 DOI: 10.1016/j.sjbs.2012.11.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 11/07/2012] [Accepted: 11/07/2012] [Indexed: 11/30/2022] Open
Abstract
Cadmium (Cd) in soil is enriched through several leaky management agricultural practices and natural resources. Cd enriched soil is inevitable cause of nutritional stress besides Cd induced toxicity symptoms and physiological malfunctions. Redox signals shift toward oxidative stress which accelerates cellular damage and elicits defense mechanism at the cost of growth. Plants get enriched with this toxic, abundant and undesirable element through 'mineral uptake system' non-specifically. Different components and pathways have been marked cooperating in cellular sequestration and systemic localization of Cd, escaped from avoidance and efflux. Cd induced metabolic alteration led to electron leakage as ROS, reduced photosynthesis and carbon fixation. Compromised primary metabolism negatively feedbacks the plant growth, result into loss of potential crop yield.
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Affiliation(s)
- Mohd Irfan
- Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh 202 002, U.P., India
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39
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Wang F, Wang Z, Zhu C. Heteroexpression of the wheat phytochelatin synthase gene (TaPCS1) in rice enhances cadmium sensitivity. Acta Biochim Biophys Sin (Shanghai) 2012; 44:886-93. [PMID: 23017837 DOI: 10.1093/abbs/gms073] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Phytochelatin synthase (PCS) (EC 2.3.2.15) catalyzes the final step of phytochelatins (PCs) biosynthesis. PCs are a family of cysteine-rich thiol-reactive and heavy metal-binding peptides that play an important role in sequestration and detoxification of heavy metals in plants. Previous studies have indicated that plants that overexpressed PCS displayed contrasting phenotypes, ranging from enhanced cadmium (Cd) tolerance to Cd hypersensitivity in Arabidopsis thaliana. In this study, the wheat phytochelatin synthase gene, TaPCS1, was heteroexpressed in wild-type rice (Oryza sativa L., cv. Zhonghua 11) to evaluate the relationship between synthesis of PCs and Cd tolerance in rice. Data showed that the heteroexpression of TaPCS1 in rice enhanced Cd sensitivity and significantly increased Cd accumulation in shoots, but not in roots. Additionally, the PCS line exhibited a much higher content of PCs and non-protein thiols (NPTs) in shoots. Prominent changes in NPT composition led to reduced glutathione pool depletion and higher Cd content in cell organelles in shoots, followed by higher oxidative stress, which might result in Cd sensitivity. Therefore, the heteroexpression of TaPCS1 in rice is capable of increasing Cd accumulation in rice shoots and enhancing Cd sensitivity.
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Affiliation(s)
- Feijuan Wang
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, China
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40
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Shukla D, Kesari R, Mishra S, Dwivedi S, Tripathi RD, Nath P, Trivedi PK. Expression of phytochelatin synthase from aquatic macrophyte Ceratophyllum demersum L. enhances cadmium and arsenic accumulation in tobacco. PLANT CELL REPORTS 2012; 31:1687-99. [PMID: 22614255 DOI: 10.1007/s00299-012-1283-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 04/27/2012] [Accepted: 05/03/2012] [Indexed: 05/22/2023]
Abstract
UNLABELLED Phytochelatin synthase (PCS), the key enzyme involved in heavy metal detoxification and accumulation has been used from various sources to develop transgenic plants for the purpose of phytoremediation. However, some of the earlier studies provided contradictory results. Most of the PCS genes were isolated from plants that are not potential metal accumulators. In this study, we have isolated PCS gene from Ceratophyllum demersum cv. L. (CdPCS1), a submerged rootless aquatic macrophyte, which is considered as potential accumulator of heavy metals. The CdPCS1 cDNA of 1,757 bp encodes a polypeptide of 501 amino acid residues and differs from other known PCS with respect to the presence of a number of cysteine residues known for their interaction with heavy metals. Complementation of cad1-3 mutant of Arabidopsis deficient in PC (phytochelatin) biosynthesis by CdPCS1 suggests its role in the synthesis of PCs. Transgenic tobacco plants expressing CdPCS1 showed several-fold increased PC content and precursor non-protein thiols with enhanced accumulation of cadmium (Cd) and arsenic (As) without significant decrease in plant growth. We conclude that CdPCS1 encodes functional PCS and may be part of metal detoxification mechanism of the heavy metal accumulating plant C. demersum. KEY MESSAGE Heterologous expression of PCS gene from C. demersum complements Arabidopsis cad1-3 mutant and leads to enhanced accumulation of Cd and As in transgenic tobacco.
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Affiliation(s)
- Devesh Shukla
- CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India
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41
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Jobe TO, Sung DY, Akmakjian G, Pham A, Komives EA, Mendoza-Cózatl DG, Schroeder JI. Feedback inhibition by thiols outranks glutathione depletion: a luciferase-based screen reveals glutathione-deficient γ-ECS and glutathione synthetase mutants impaired in cadmium-induced sulfate assimilation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:783-95. [PMID: 22283708 PMCID: PMC4688143 DOI: 10.1111/j.1365-313x.2012.04924.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Plants exposed to heavy metals rapidly induce changes in gene expression that activate and enhance detoxification mechanisms, including toxic-metal chelation and the scavenging of reactive oxygen species. However, the mechanisms mediating toxic heavy metal-induced gene expression remain largely unknown. To genetically elucidate cadmium-specific transcriptional responses in Arabidopsis, we designed a genetic screen based on the activation of a cadmium-inducible reporter gene. Microarray studies identified a high-affinity sulfate transporter (SULTR1;2) among the most robust and rapid cadmium-inducible transcripts. The SULTR1;2 promoter (2.2 kb) was fused with the firefly luciferase reporter gene to quantitatively report the transcriptional response of plants exposed to cadmium. Stably transformed luciferase reporter lines were ethyl methanesulfonate (EMS) mutagenized, and stable M(2) seedlings were screened for an abnormal luciferase response during exposure to cadmium. The screen identified non-allelic mutant lines that fell into one of three categories: (i) super response to cadmium (SRC) mutants; (ii) constitutive response to cadmium (CRC) mutants; or (iii) non-response and reduced response to cadmium (NRC) mutants. Two nrc mutants, nrc1 and nrc2, were mapped, cloned and further characterized. The nrc1 mutation was mapped to the γ-glutamylcysteine synthetase gene and the nrc2 mutation was identified as the first viable recessive mutant allele in the glutathione synthetase gene. Moreover, genetic, HPLC mass spectrometry, and gene expression analysis of the nrc1 and nrc2 mutants, revealed that intracellular glutathione depletion alone would be insufficient to induce gene expression of sulfate uptake and assimilation mechanisms. Our results modify the glutathione-depletion driven model for sulfate assimilation gene induction during cadmium stress, and suggest that an enhanced oxidative state and depletion of upstream thiols, in addition to glutathione depletion, are necessary to induce the transcription of sulfate assimilation genes during early cadmium stress.
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Affiliation(s)
- Timothy O. Jobe
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
| | - Dong-Yul Sung
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
| | - Garo Akmakjian
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
| | - Allis Pham
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
| | - Elizabeth A. Komives
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0378, USA
| | - David G. Mendoza-Cózatl
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
- Division of Plant Sciences, C. S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211-7310, USA
| | - Julian I. Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
- For correspondence ()
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42
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Abstract
Of the mechanisms known to protect vascular plants and some algae, fungi and invertebrates from the toxic effects of non-essential heavy metals such as As, Cd or Hg, one of the most sophisticated is the enzyme-catalyzed synthesis of phytochelatins (PCs). PCs, (γ-Glu-Cys)(n) Gly polymers, which serve as high-affinity, thiol-rich cellular chelators and contribute to the detoxification of heavy metal ions, are derived from glutathione (GSH; γ-Glu-Cys-Gly) and related thiols in a reaction catalyzed by phytochelatin synthases (PC synthases, EC 2.3.2.15). Using the enzyme from Arabidopsis thaliana (AtPCS1) as a model, the reasoning and experiments behind the conclusion that PC synthases are novel papain-like Cys protease superfamily members are presented. The status of S-substituted GSH derivatives as generic PC synthase substrates and the sufficiency of the N-terminal domain of the enzyme from eukaryotic and its half-size equivalents from prokaryotic sources, for net PC synthesis and deglycylation of GSH and its derivatives, respectively, are emphasized. The question of the common need or needs met by PC synthases and their homologs is discussed. Of the schemes proposed to account for the combined protease and peptide polymerase capabilities of the eukaryotic enzymes vs the limited protease capabilities of the prokaryotic enzymes, two that will be considered are the storage and homeostasis of essential heavy metals in eukaryotes and the metabolism of S-substituted GSH derivatives in both eukaryotes and prokaryotes.
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Affiliation(s)
- Philip A Rea
- Carolyn Hoff Lynch Biology Laboratory, Plant Science Institute, Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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43
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Brulle F, Lemière S, Waterlot C, Douay F, Vandenbulcke F. Gene expression analysis of 4 biomarker candidates in Eisenia fetida exposed to an environmental metallic trace elements gradient: a microcosm study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2011; 409:5470-5482. [PMID: 21937088 DOI: 10.1016/j.scitotenv.2011.08.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 08/17/2011] [Accepted: 08/20/2011] [Indexed: 05/31/2023]
Abstract
Past activities of 2 smelters (Metaleurop Nord and Nyrstar) led to the accumulation of high amounts of Metal Trace Elements (TEs) in top soils of the Noyelles-Godault/Auby area, Northern France. Earthworms were exposed to polluted soils collected in this area to study and better understand the physiological changes, the mechanisms of acclimation, and detoxification resulting from TE exposure. Previously we have cloned and transcriptionally characterized potential biomarkers from immune cells of the ecotoxicologically important earthworm species Eisenia fetida exposed in vivo to TE-spiked standard soils. In the present study, analysis of expression kinetics of four candidate indicator genes (Cadmium-metallothionein, coactosin like protein, phytochelatin synthase and lysenin) was performed in E. fetida after microcosm exposures to natural soils exhibiting an environmental cadmium (Cd) gradient in a kinetic manner. TE body burdens were also measured. This microcosm study provided insights into: (1) the ability of the 4 tested genes to serve as expression biomarkers, (2) detoxification processes through the expression analysis of selected genes, and (3) influence of land uses on the response of potential biomarkers (gene expression or TE uptake).
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Affiliation(s)
- Franck Brulle
- University Lille Nord de France, F-59000 Lille, France
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44
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Brunetti P, Zanella L, Proia A, De Paolis A, Falasca G, Altamura MM, Sanità di Toppi L, Costantino P, Cardarelli M. Cadmium tolerance and phytochelatin content of Arabidopsis seedlings over-expressing the phytochelatin synthase gene AtPCS1. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:5509-19. [PMID: 21841172 PMCID: PMC3223047 DOI: 10.1093/jxb/err228] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 06/27/2011] [Accepted: 06/28/2011] [Indexed: 05/18/2023]
Abstract
Previous studies demonstrated that expression of the Arabidopsis phytochelatin (PC) biosynthetic gene AtPCS1 in Nicotiana tabacum plants increases the Cd tolerance in the presence of exogenous glutathione (GSH). In this paper, the Cd tolerance of Arabidopsis plants over-expressing AtPCS1 (AtPCSox lines) has been analysed and the differences between Arabidopsis and tobacco are shown. Based on the analysis of seedling fresh weight, primary root length, and alterations in root anatomy, evidence is provided that, at relatively low Cd concentrations, the Cd tolerance of AtPCSox lines is lower than the wild type, while AtPCS1 over-expressing tobacco is more tolerant to Cd than the wild type. At higher Cd concentrations, Arabidopsis AtPCSox seedlings are more tolerant to Cd than the wild type, while tobacco AtPCS1 seedlings are as sensitive as the wild type. Exogenous GSH, in contrast to what was observed in tobacco, did not increase the Cd tolerance of AtPCSox lines. The PC content in wild-type Arabidopsis at low Cd concentrations is more than three times higher than in tobacco and substantial differences were also found in the PC chain lengths. These data indicate that the differences in Cd tolerance and in its dependence on exogenous GSH between Arabidopsis and tobacco are due to species-specific differences in the endogenous content of PCs and GSH and may be in the relative abundance of PCs of different length.
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Affiliation(s)
- Patrizia Brunetti
- Dipartimento di Biologia e Biotecnologie (formerly Dipartimento di Genetica e Biologia Molecolare), Sapienza Università di Roma, Italy
| | - Letizia Zanella
- Dipartimento di Biologia Ambientale (formerly Dipartimento di Biologia Vegetale), Sapienza Università di Roma, Italy
| | - Alessandra Proia
- IBPM-CNR Dipartimento di Biologia e Biotecnologie (formerly Dipartimento di Genetica e Biologia Molecolare), Sapienza Università di Roma, Italy
| | | | - Giuseppina Falasca
- Dipartimento di Biologia Ambientale (formerly Dipartimento di Biologia Vegetale), Sapienza Università di Roma, Italy
| | - Maria Maddalena Altamura
- Dipartimento di Biologia Ambientale (formerly Dipartimento di Biologia Vegetale), Sapienza Università di Roma, Italy
| | | | - Paolo Costantino
- Dipartimento di Biologia e Biotecnologie (formerly Dipartimento di Genetica e Biologia Molecolare), Sapienza Università di Roma, Italy
| | - Maura Cardarelli
- IBPM-CNR Dipartimento di Biologia e Biotecnologie (formerly Dipartimento di Genetica e Biologia Molecolare), Sapienza Università di Roma, Italy
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45
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Liu GY, Zhang YX, Chai TY. Phytochelatin synthase of Thlaspi caerulescens enhanced tolerance and accumulation of heavy metals when expressed in yeast and tobacco. PLANT CELL REPORTS 2011; 30:1067-76. [PMID: 21327392 DOI: 10.1007/s00299-011-1013-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 01/01/2011] [Accepted: 01/11/2011] [Indexed: 05/22/2023]
Abstract
Phytochelatin synthase (PCS) is key enzyme for heavy metal detoxification and accumulation in plant. In this study, we isolated the PCS gene TcPCS1 from the hyperaccumulator Thlaspi caerulescens. Overexpression of TcPCS1 enhanced PC production in tobacco. Cd accumulation in the roots and shoots of TcPCS1 transgenic seedlings was increased compared to the wild type (WT), while Cd translocation from roots to shoots was not affected under Cd treatment. The root length of the TcPCS1 transgenic tobacco seedlings was significantly longer than that of the WT under Cd stress. These data indicate that TcPCS1 expression might increase Cd accumulation and tolerance in transgenic tobacco. In addition, the malondialdehyde content in TcPCS1 plants was below that of the wild type. However, the antioxidant enzyme activities of superoxide dismutase, peroxidase and catalase were found to be significantly higher than those of the WT when the transgenic plant was exposed to Cd stress. This suggests that the increase in PC production might enhance the Cd accumulation and thus increase the oxidative stress induced by the cadmium. The production of PCs could cause a transient decrease in the cytosolic glutathione (GSH) pool, and Cd and lower GSH concentration caused an increase in the oxidative response. We also determined TcPCS1 in Thlaspi caerulescens was regulated after exposure to various concentrations of CdCl(2) over different treatment times. Expression of TcPCS1 leading to increased Cd accumulation and enhanced metal tolerance, but the Cd contents were restrained by adding zinc in Saccharomyces cerevisiae transformants.
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MESH Headings
- Adaptation, Physiological/drug effects
- Adaptation, Physiological/genetics
- Aminoacyltransferases/genetics
- Aminoacyltransferases/metabolism
- Cadmium/metabolism
- Cadmium/toxicity
- Gene Expression Profiling
- Gene Expression Regulation, Plant/drug effects
- Glutathione/metabolism
- Malondialdehyde/metabolism
- Metals, Heavy/metabolism
- Metals, Heavy/toxicity
- Organ Specificity/drug effects
- Organ Specificity/genetics
- Phytochelatins/metabolism
- Plant Roots/anatomy & histology
- Plant Roots/drug effects
- Plant Roots/metabolism
- Plant Shoots/drug effects
- Plant Shoots/metabolism
- Plants, Genetically Modified
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Reactive Oxygen Species/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Saccharomyces cerevisiae/metabolism
- Stress, Physiological/drug effects
- Stress, Physiological/genetics
- Thlaspi/drug effects
- Thlaspi/enzymology
- Thlaspi/genetics
- Nicotiana/drug effects
- Nicotiana/genetics
- Nicotiana/metabolism
- Transformation, Genetic/drug effects
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Affiliation(s)
- Ge-Yu Liu
- College of Life Science, Graduate University of Chinese Academy of Sciences, Yuquan Rd 19, Beijing 100049, China
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46
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Wysocki R, Tamás MJ. How Saccharomyces cerevisiae copes with toxic metals and metalloids. FEMS Microbiol Rev 2011; 34:925-51. [PMID: 20374295 DOI: 10.1111/j.1574-6976.2010.00217.x] [Citation(s) in RCA: 202] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Toxic metals and metalloids are widespread in nature and can locally reach fairly high concentrations. To ensure cellular protection and survival in such environments, all organisms possess systems to evade toxicity and acquire tolerance. This review provides an overview of the molecular mechanisms that contribute to metal toxicity, detoxification and tolerance acquisition in budding yeast Saccharomyces cerevisiae. We mainly focus on the metals/metalloids arsenic, cadmium, antimony, mercury, chromium and selenium, and emphasize recent findings on sensing and signalling mechanisms and on the regulation of tolerance and detoxification systems that safeguard cellular and genetic integrity.
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Affiliation(s)
- Robert Wysocki
- Institute of Genetics and Microbiology, University of Wroclaw, Wroclaw, Poland
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47
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Mendoza-Cózatl DG, Zhai Z, Jobe TO, Akmakjian GZ, Song WY, Limbo O, Russell MR, Kozlovskyy VI, Martinoia E, Vatamaniuk OK, Russell P, Schroeder JI. Tonoplast-localized Abc2 transporter mediates phytochelatin accumulation in vacuoles and confers cadmium tolerance. J Biol Chem 2010; 285:40416-26. [PMID: 20937798 PMCID: PMC3003340 DOI: 10.1074/jbc.m110.155408] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 09/20/2010] [Indexed: 11/06/2022] Open
Abstract
Phytochelatins mediate tolerance to heavy metals in plants and some fungi by sequestering phytochelatin-metal complexes into vacuoles. To date, only Schizosaccharomyces pombe Hmt1 has been described as a phytochelatin transporter and attempts to identify orthologous phytochelatin transporters in plants and other organisms have failed. Furthermore, recent data indicate that the hmt1 mutant accumulates significant phytochelatin levels in vacuoles, suggesting that unidentified phytochelatin transporters exist in fungi. Here, we show that deletion of all vacuolar ABC transporters abolishes phytochelatin accumulation in S. pombe vacuoles and abrogates (35)S-PC(2) uptake into S. pombe microsomal vesicles. Systematic analysis of the entire S. pombe ABC transporter family identified Abc2 as a full-size ABC transporter (ABCC-type) that mediates phytochelatin transport into vacuoles. The S. pombe abc1 abc2 abc3 abc4 hmt1 quintuple and abc2 hmt1 double mutant show no detectable phytochelatins in vacuoles. Abc2 expression restores phytochelatin accumulation into vacuoles and suppresses the cadmium sensitivity of the abc quintuple mutant. A novel, unexpected, function of Hmt1 in GS-conjugate transport is also shown. In contrast to Hmt1, Abc2 orthologs are widely distributed among kingdoms and are proposed as the long-sought vacuolar phytochelatin transporters in plants and other organisms.
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Affiliation(s)
- David G. Mendoza-Cózatl
- From the Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093
| | - Zhiyang Zhai
- the Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853
| | - Timothy O. Jobe
- From the Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093
| | - Garo Z. Akmakjian
- From the Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093
| | - Won-Yong Song
- the Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland, and
| | - Oliver Limbo
- the Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Matthew R. Russell
- the Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
| | | | - Enrico Martinoia
- the Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland, and
| | - Olena K. Vatamaniuk
- the Department of Crop and Soil Sciences, Cornell University, Ithaca, New York 14853
| | - Paul Russell
- the Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
| | - Julian I. Schroeder
- From the Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093
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48
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Bolchi A, Ruotolo R, Marchini G, Vurro E, di Toppi LS, Kohler A, Tisserant E, Martin F, Ottonello S. Genome-wide inventory of metal homeostasis-related gene products including a functional phytochelatin synthase in the hypogeous mycorrhizal fungus Tuber melanosporum. Fungal Genet Biol 2010; 48:573-84. [PMID: 21094264 DOI: 10.1016/j.fgb.2010.11.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 10/27/2010] [Accepted: 11/07/2010] [Indexed: 11/27/2022]
Abstract
Ectomycorrhizal fungi are thought to enhance mineral nutrition of their host plants and to confer increased tolerance toward toxic metals. However, a global view of metal homeostasis-related genes and pathways in these organisms is still lacking. Building upon the genome sequence of Tuber melanosporum and on transcriptome analyses, we set out to systematically identify metal homeostasis-related genes in this plant-symbiotic ascomycete. Candidate gene products (101) were subdivided into three major functional classes: (i) metal transport (58); (ii) oxidative stress defence (32); (iii) metal detoxification (11). The latter class includes a small-size metallothionein (TmelMT) that was functionally validated in yeast, and phytochelatin synthase (TmelPCS), the first enzyme of this kind to be described in filamentous ascomycetes. Recombinant TmelPCS was shown to support GSH-dependent, metal-activated phytochelatin synthesis in vitro and to afford increased Cd/Cu tolerance to metal hypersensitive yeast strains. Metal transporters, especially those related to Cu and Zn trafficking, displayed the highest expression levels in mycorrhizae, suggesting extensive translocation of both metals to root cells as well as to fungal metalloenzymes (e.g., laccase) that are strongly upregulated in symbiotic hyphae.
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Affiliation(s)
- Angelo Bolchi
- Department of Biochemistry and Molecular and Functional Biology, University of Parma, 43100 Parma, Italy
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49
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Brulle F, Morgan AJ, Cocquerelle C, Vandenbulcke F. Transcriptomic underpinning of toxicant-mediated physiological function alterations in three terrestrial invertebrate taxa: a review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2010; 158:2793-2808. [PMID: 20619942 DOI: 10.1016/j.envpol.2010.06.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 06/09/2010] [Accepted: 06/12/2010] [Indexed: 05/29/2023]
Abstract
Diverse anthropogenic activities often lead to the accumulation of inorganic and organic residues in topsoils. Biota living in close contact with contaminated soils may experience stress at different levels of biological organisation throughout the continuum from the molecular-genetic to ecological and community levels. To date, the relationship between changes at the molecular (mRNA expression) and biochemical/physiological levels evoked by exposures to chemical compounds has been partially established in a limited number of terrestrial invertebrate species. Recently, the advent of a family of transcriptomic tools (e.g. Real-time PCR, Subtractive Suppressive Hybridization, Expressed Sequence Tag sequencing, pyro-sequencing technologies, Microarray chips), together with supporting informatic and statistical procedures, have permitted the robust analyses of global gene expression changes within an ecotoxicological context. This review focuses on how transcriptomics is enlightening our understanding of the molecular-genetic responses of three contrasting terrestrial macroinvertebrate taxa (nematodes, earthworms, and springtails) to inorganics, organics, and agrochemicals.
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50
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Zeitoun-Ghandour S, Charnock JM, Hodson ME, Leszczyszyn OI, Blindauer CA, Stürzenbaum SR. The two Caenorhabditis elegans metallothioneins (CeMT-1 and CeMT-2) discriminate between essential zinc and toxic cadmium. FEBS J 2010; 277:2531-42. [PMID: 20553489 DOI: 10.1111/j.1742-4658.2010.07667.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nematode Caenorhabditis elegans expresses two metallothioneins (MTs), CeMT-1 and CeMT-2, that are believed to be key players in the protection against metal toxicity. In this study, both isoforms were expressed in vitro in the presence of either Zn(II) or Cd(II). Metal binding stoichiometries and affinities were determined by ESI-MS and NMR, respectively. Both isoforms had equal zinc binding ability, but differed in their cadmium binding behaviour, with higher affinity found for CeMT-2. In addition, wild-type C. elegans, single MT knockouts and a double MT knockout allele were exposed to zinc (340 microm) or cadmium (25 microm) to investigate effects in vivo. Zinc levels were significantly increased in all knockout strains, but were most pronounced in the CeMT-1 knockout, mtl-1 (tm1770), while cadmium accumulation was highest in the CeMT-2 knockout, mtl-2 (gk125) and the double knockout mtl-1;mtl-2 (zs1). In addition, metal speciation was assessed by X-ray absorption fine-structure spectroscopy. This showed that O-donating, probably phosphate-rich, ligands play a dominant role in maintaining the physiological concentration of zinc, independently of metallothionein status. In contrast, cadmium was shown to coordinate with thiol groups, and the cadmium speciation of the wild-type and the CeMT-2 knockout strain was distinctly different to the CeMT-1 and double knockouts. Taken together, and supported by a simple model calculation, these findings show for the first time that the two MT isoforms have differential affinities towards Cd(II) and Zn(II) at a cellular level, and this is reflected at the protein level. This suggests that the two MT isoforms have distinct in vivo roles.
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