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Saeed SH, Shah GM, Mahmood Q, Shaheen S, Zeb BS, Nawazish S, Almutairi KF, Avila-Quezada GD, Abd Allah EF. Phytoremediation ability and selected genetic transcription in Hydrocotyle umbellata-under cadmium stress. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2024; 26:1144-1153. [PMID: 38143325 DOI: 10.1080/15226514.2023.2295354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2023]
Abstract
Cadmium (Cd) is the most toxic element which may cause serious consequences to microbial communities, animals, and plants. The use of green technologies like phytoremediation employs plants with high biomass and metal tolerance to extract toxic metals from their rooting zones. In the present work, Hydrocotyle umbellata was exposed to five Cd concentrations (2, 4, 6, 8, and 10 µmol) in triplicates to judge its phytoextraction ability. Effects of metal exposure on chlorophyll (Chl), bio-concentration factor (BCF), translocation factor (TF), and electrolyte leakage (EL) were analyzed after 10 days of treatment. Metal-responding genes were also observed through transcriptomic analysis. Roots were the primary organs for cadmium accumulation followed by stolon and leaves. There was an increase in EL. Plants showed various symptoms under increasing metal stress namely, chlorosis, browning of the leaf margins, burn-like areas on the leaves, and stunted growth, suggesting a positive relationship between EL, and programmed cell death (PCD). Metal-responsive genes, including glutathione, expansin, and cystatin were equally expressed. The phytoextraction capacity and adaptability of H. umbellata L. against Cd metal stress was also demonstrated by BCF more than 1 and TF less than 1.
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Affiliation(s)
- Sidra H Saeed
- Department of Botany, Hazara University Garden Campus, Mansehra, Pakistan
| | - Ghulam M Shah
- Department of Botany, Hazara University Garden Campus, Mansehra, Pakistan
| | - Qaisar Mahmood
- Department of Environmental Sciences, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, Pakistan
- Department of Environmental Sciences, Kohsar University, Murree, Pakistan
| | - Shahida Shaheen
- Department of Biology, College of Science, University of Bahrain, Sakhir, Bahrain
| | - Bibi S Zeb
- Department of Environmental Sciences, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, Pakistan
| | - Shamyla Nawazish
- Department of Environmental Sciences, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, Pakistan
| | - Khalid F Almutairi
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
| | | | - Elsayed Fathi Abd Allah
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
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Rajput VD, Harish, Singh RK, Verma KK, Sharma L, Quiroz-Figueroa FR, Meena M, Gour VS, Minkina T, Sushkova S, Mandzhieva S. Recent Developments in Enzymatic Antioxidant Defence Mechanism in Plants with Special Reference to Abiotic Stress. BIOLOGY 2021; 10:267. [PMID: 33810535 PMCID: PMC8066271 DOI: 10.3390/biology10040267] [Citation(s) in RCA: 171] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/12/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022]
Abstract
The stationary life of plants has led to the evolution of a complex gridded antioxidant defence system constituting numerous enzymatic components, playing a crucial role in overcoming various stress conditions. Mainly, these plant enzymes are superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferases (GST), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR), which work as part of the antioxidant defence system. These enzymes together form a complex set of mechanisms to minimise, buffer, and scavenge the reactive oxygen species (ROS) efficiently. The present review is aimed at articulating the current understanding of each of these enzymatic components, with special attention on the role of each enzyme in response to the various environmental, especially abiotic stresses, their molecular characterisation, and reaction mechanisms. The role of the enzymatic defence system for plant health and development, their significance, and cross-talk mechanisms are discussed in detail. Additionally, the application of antioxidant enzymes in developing stress-tolerant transgenic plants are also discussed.
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Affiliation(s)
- Vishnu D. Rajput
- Academy of Biology and Biotechnology, Southern Federal University, 344090 Rostov-on-Don, Russia; (T.M.); (S.S.); (S.M.)
| | - Harish
- Department of Botany, Mohan Lal Sukhadia University, Udaipur, Rajasthan 313001, India;
| | - Rupesh Kumar Singh
- Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal
| | - Krishan K. Verma
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement/Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China;
| | - Lav Sharma
- Centre for the Research and Technology of Agro-Environment and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal;
| | - Francisco Roberto Quiroz-Figueroa
- Laboratorio de Fitomejoramiento Molecular, Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Sinaloa (CIIDIR-IPN Unidad Sinaloa), Instituto Politécnico Nacional, Blvd. Juan de Dios Bátiz Paredes no. 250, Col. San Joachín, C.P., 81101 Guasave, Mexico;
| | - Mukesh Meena
- Department of Botany, Mohan Lal Sukhadia University, Udaipur, Rajasthan 313001, India;
| | - Vinod Singh Gour
- Amity Institute of Biotechnology, Amity University Rajasthan, NH 11C, Kant Kalwar, Jaipur 303002, India;
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, 344090 Rostov-on-Don, Russia; (T.M.); (S.S.); (S.M.)
| | - Svetlana Sushkova
- Academy of Biology and Biotechnology, Southern Federal University, 344090 Rostov-on-Don, Russia; (T.M.); (S.S.); (S.M.)
| | - Saglara Mandzhieva
- Academy of Biology and Biotechnology, Southern Federal University, 344090 Rostov-on-Don, Russia; (T.M.); (S.S.); (S.M.)
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Kaur M, Sharma S. Influence of selenite and selenate on growth, leaf physiology and antioxidant defense system in wheat (Triticum aestivum L.). JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2018; 98:5700-5710. [PMID: 29736998 DOI: 10.1002/jsfa.9117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 04/30/2018] [Accepted: 05/03/2018] [Indexed: 05/12/2023]
Abstract
BACKGROUND Selenium (Se) induced oxidative stress as well as synthesis of non-specific selenoproteins has been attributed to its toxicity in plants. Selenium toxicity can affect growth, chlorophyll and protein synthesis and crop yield. This study reveals the effects of different sources (sodium selenite and sodium selenate) and levels (2 and 4 mg Se kg-1 soil) of Se on its uptake, leaf physiology, antioxidant defense system, isoenzymic patterns and mitochondrial activity in wheat cultivar PBW621 at tillering and ear-initiation stages. RESULTS Higher Se accumulation in leaves of wheat plants was observed in selenate than control and selenite treatments. Selenium tolerance index, chlorophyll, photosynthetic efficiency, mitochondrial reduction test, electron transport system activity, lipid peroxidation, proline and glutathione in Se-treated wheat plants decreased significantly as compared to control. Significant increase in hydrogen peroxide and activities of antioxidant enzymes, namely catalase, peroxidase, superoxide dismutase, glutathione reductase in leaves was due to the presence of Se-induced oxidative stress in wheat plants. CONCLUSION Wheat cultivar PBW621 could adapt to applied selenite concentrations by developing antioxidant defense system but selenate treated plants could exhibit toxicity tolerance up to 2 mg kg-1 and died at high concentrations due to damage to tissue development and function. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Manpreet Kaur
- Department of Biochemistry, Punjab Agricultural University, Ludhiana, India
| | - Sucheta Sharma
- Department of Biochemistry, Punjab Agricultural University, Ludhiana, India
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Singh S, Parihar P, Singh R, Singh VP, Prasad SM. Heavy Metal Tolerance in Plants: Role of Transcriptomics, Proteomics, Metabolomics, and Ionomics. FRONTIERS IN PLANT SCIENCE 2016; 6:1143. [PMID: 26904030 PMCID: PMC4744854 DOI: 10.3389/fpls.2015.01143] [Citation(s) in RCA: 422] [Impact Index Per Article: 52.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 12/02/2015] [Indexed: 05/18/2023]
Abstract
Heavy metal contamination of soil and water causing toxicity/stress has become one important constraint to crop productivity and quality. This situation has further worsened by the increasing population growth and inherent food demand. It has been reported in several studies that counterbalancing toxicity due to heavy metal requires complex mechanisms at molecular, biochemical, physiological, cellular, tissue, and whole plant level, which might manifest in terms of improved crop productivity. Recent advances in various disciplines of biological sciences such as metabolomics, transcriptomics, proteomics, etc., have assisted in the characterization of metabolites, transcription factors, and stress-inducible proteins involved in heavy metal tolerance, which in turn can be utilized for generating heavy metal-tolerant crops. This review summarizes various tolerance strategies of plants under heavy metal toxicity covering the role of metabolites (metabolomics), trace elements (ionomics), transcription factors (transcriptomics), various stress-inducible proteins (proteomics) as well as the role of plant hormones. We also provide a glance of some strategies adopted by metal-accumulating plants, also known as "metallophytes."
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Affiliation(s)
- Samiksha Singh
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Parul Parihar
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Rachana Singh
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
| | - Vijay P. Singh
- Department of Botany, Government Ramanuj Pratap Singhdev Post Graduate College, Sarguja UniversityBaikunthpur, India
| | - Sheo M. Prasad
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of AllahabadAllahabad, India
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Functional Validation of Phragmites communis Glutathione Reductase (PhaGR) as an Essential Enzyme in Salt Tolerance. Appl Biochem Biotechnol 2015; 175:3418-30. [DOI: 10.1007/s12010-015-1514-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 01/21/2015] [Indexed: 11/26/2022]
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Glutathione reductase from Brassica rapa affects tolerance and the redox state but not fermentation ability in response to oxidative stress in genetically modified Saccharomyces cerevisiae. World J Microbiol Biotechnol 2012; 28:1901-15. [PMID: 22806013 DOI: 10.1007/s11274-011-0988-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 12/19/2011] [Indexed: 10/14/2022]
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Kim IS, Shin SY, Kim YS, Kim HY, Yoon HS. Expression of a glutathione reductase from Brassica rapa subsp. pekinensis enhanced cellular redox homeostasis by modulating antioxidant proteins in Escherichia coli. Mol Cells 2009; 28:479-87. [PMID: 19936628 DOI: 10.1007/s10059-009-0168-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2009] [Accepted: 10/28/2009] [Indexed: 02/03/2023] Open
Abstract
Glutathione reductase (GR) is an enzyme that recycles a key cellular antioxidant molecule glutathione (GSH) from its oxidized form (GSSG) thus maintaining cellular redox homeostasis. A recombinant plasmid to overexpress a GR of Brassica rapa subsp. pekinensis (BrGR) in E. coli BL21 (DE3) was constructed using an expression vector pKM260. Expression of the introduced gene was confirmed by semiquantitative RT-PCR, immunoblotting and enzyme assays. Purification of the BrGR protein was performed by IMAC method and indicated that the BrGR was a dimmer. The BrGR required NADPH as a cofactor and specific activity was approximately 458 U. The BrGR-expressing E. coli cells showed increased GR activity and tolerance to H(2)O(2), menadione, and heavy metal (CdCl(2), ZnCl(2) and AlCl(2))-mediated growth inhibition. The ectopic expression of BrGR provoked the co-regulation of a variety of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase. Consequently, the transformed cells showed decreased hydroperoxide levels when exposed to stressful conditions. A proteomic analysis demonstrated the higher level of induction of proteins involved in glycolysis, detoxification/oxidative stress response, protein folding, transport/binding proteins, cell envelope/porins, and protein translation and modification when exposed to H(2)O(2) stress. Taken together, these results indicate that the plant GR protein is functional in a cooperative way in the E. coli system to protect cells against oxidative stress.
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Affiliation(s)
- Il-Sup Kim
- Department of Biology, Kyungpook National University, Daegu 702-701, Korea
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Castagna A, Ranieri A. Detoxification and repair process of ozone injury: from O3 uptake to gene expression adjustment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2009; 157:1461-1469. [PMID: 18954925 DOI: 10.1016/j.envpol.2008.09.029] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Accepted: 09/12/2008] [Indexed: 05/27/2023]
Abstract
Plants react to O(3) threat by setting up a variety of defensive strategies involving the co-ordinated modulation of stress perception, signalling and metabolic responses. Although stomata largely controls O(3) uptake, differences in O(3) tolerance cannot always be ascribed to changes in stomatal conductance but cell protective and repair processes should be taken into account. O(3)-driven ROS production in the apoplast induces a secondary, active, self-propagating generation of ROS, whose levels must be finely tuned, by many enzymatic and non-enzymatic antioxidant systems, to induce gene activation without determining uncontrolled cell death. Additional signalling molecules, as ethylene, jasmonic and salicylic acid are also crucial to determine the spreading and the containment of leaf lesions. The main recent results obtained on O(3) sensing, signal transduction, ROS formation and detoxification mechanisms are here discussed.
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Affiliation(s)
- A Castagna
- Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
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Ekmekçi Y, Tanyolaç D, Ayhan B. Effects of cadmium on antioxidant enzyme and photosynthetic activities in leaves of two maize cultivars. JOURNAL OF PLANT PHYSIOLOGY 2008; 165:600-11. [PMID: 17728009 DOI: 10.1016/j.jplph.2007.01.017] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Revised: 01/24/2007] [Accepted: 01/24/2007] [Indexed: 05/17/2023]
Abstract
Effects of cadmium (Cd(2+)) on photosynthetic and antioxidant activities of maize (Zea mays L.) cultivars (3223 and 32D99) were investigated. Fourteen-day-old cultivar seedlings were exposed to different Cd concentrations [0, 0.3, 0.6 and 0.9mM Cd(NO(3))(2) x 4H(2)O] for 8 days. The results of chlorophyll fluorescence indicated that different levels of Cd affected photochemical efficiency in 3223 much more than that in 32D99. In parallel, the level of Cd at 0.9mM caused oxidative damage but did not indicate cessation of PSII activity of the cultivars; plant death was not observed at highly toxic Cd levels. Additionally, the increase in Cd concentration caused loss of chlorophylls and carotenoid and membrane damage in both cultivars, but greater membrane damage was observed in 3223 than in 32D99. Depending on Cd accumulation, a significant reduction in dry biomass was observed in both cultivars at all Cd concentrations. The accumulation of Cd was higher in roots than in leaves for both cultivars. Nevertheless, cultivar 3223 transferred more Cd from roots to leaves than did 32D99. On the other hand, our results suggest that there were similar responses in SOD, APX and GR activities with increasing Cd concentrations for both cultivars. However, POD activity significantly increased at highly toxic Cd levels in 32D99. This result may be regarded as an indication of better tolerance of the Z. mays L. cultivar 32D99 to Cd contamination.
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Affiliation(s)
- Yasemin Ekmekçi
- Hacettepe University, Faculty of Science, Department of Biology, Beytepe Campus, Ankara, Turkey.
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Torres-Franklin ML, Contour-Ansel D, Zuily-Fodil Y, Pham-Thi AT. Molecular cloning of glutathione reductase cDNAs and analysis of GR gene expression in cowpea and common bean leaves during recovery from moderate drought stress. JOURNAL OF PLANT PHYSIOLOGY 2008; 165:514-21. [PMID: 17707549 DOI: 10.1016/j.jplph.2007.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Revised: 03/14/2007] [Accepted: 03/15/2007] [Indexed: 05/16/2023]
Abstract
Two cDNAs of the enzyme glutathione reductase (GR; EC 1.6.4.2) encoding a dual-targeted isoform (dtGR) and a cytosolic isoform (cGR), were cloned from leaves of common bean (Phaseolus vulgaris L.). Moderate drought stress (Psi w=-1.5MPa) followed by re-watering was applied to common bean cultivars, one tolerant to drought (IPA), the other susceptible (Carioca) and to cowpea (Vigna unguiculata L. Walp) cultivars, one tolerant to drought (EPACE-1), and the other susceptible (1183). mRNA levels were much higher for PvcGR than for PvdtGR in all cases. Moderate drought stress induced an up-regulation of the expression of PvcGR in the susceptible cultivars. On the contrary, PvdtGR expression decreased. In the tolerant cowpea EPACE-1, GR gene expression remained stable under drought. During recovery from drought, an up-regulation of the two GR isoforms occurred, with a peak at 6-10h after re-hydration. This suggests that moderate drought stress may lead to a hardening process and acclimation tolerance. The role of GR isoforms in plant tolerance and capacity to recover from drought stress is discussed.
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Affiliation(s)
- Maria Lucia Torres-Franklin
- Laboratoire d'Ecophysiologie Moléculaire, UMR-IRD 137 BioSol, Université Paris 12, 61 Avenue du Général de Gaulle, 94010 Créteil Cedex, France
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Mohanpuria P, Rana NK, Yadav SK. Cadmium induced oxidative stress influence on glutathione metabolic genes of Camellia sinensis (L.) O. Kuntze. ENVIRONMENTAL TOXICOLOGY 2007; 22:368-74. [PMID: 17607728 DOI: 10.1002/tox.20273] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Glutathione, a tripeptide with sulfhydryl (-SH) group is a very crucial compound primarily involved in redox balance maintenance of the cellular environment. In this study, we monitored the influence of Cd exposure on the transcript levels of glutathione metabolic genes in bud tissues, the youngest leaf, of Camellia sinensis L. In addition, some physiochemical parameters were also studied. Cd exposure decreased chlorophyll and protein contents, while increase was observed in lipid peroxidation upon Cd treatments. These changes were found to be concentration and duration dependent, indicating the occurrence of oxidative stress upon Cd exposure. The transcript levels of glutathione biosynthetic genes viz. gamma-glutamylcysteine synthetase (gamma-ECS) and glutathione synthetase (GSHS) increased upon Cd exposure. Furthermore, transcript levels of glutathione reductase (GR), an enzyme involved in reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH), also showed upregulation on Cd exposure. However, the transcript levels of glutathione-S-transferase (GST), an enzyme involved in forming metal-GSH complex and help in sequestration of high levels of metal ions to vacuole, did not show any change on Cd treatment. This study document that Cd exposure induces oxidative stress in Camellia sinensis and the upregulation in transcript levels of glutathione metabolic genes except GST have suggested the role of these enzymes in the protection of plants from high level Cd exposure.
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Affiliation(s)
- Prashant Mohanpuria
- Biotechnology Division, Institute of Himalayan Bioresource Technology (CSIR), Palampur 176061, India
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Yoon HS, Lee IA, Lee H, Lee BH, Jo J. Overexpression of a eukaryotic glutathione reductase gene from Brassica campestris improved resistance to oxidative stress in Escherichia coli. Biochem Biophys Res Commun 2005; 326:618-23. [PMID: 15596144 DOI: 10.1016/j.bbrc.2004.11.095] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Indexed: 01/01/2023]
Abstract
Glutathione reductase (GR) plays an essential role in a cell's defense against reactive oxygen metabolites by sustaining the reduced status of an important antioxidant glutathione. We constructed a recombinant plasmid based on the expression vector pET-18a that overexpresses a eukaryotic GR from Brassica campestris (BcGR) in Escherichia coli. For comparative analyses, E. coli GR (EcGR) was also subcloned in the same manner. The transformed E. coli with the recombinant constructs accumulated a high level of GR transcripts upon IPTG induction. Also, Western blot analysis showed overproduction of the BcGR protein in a soluble fraction of the transformed E. coli extract. When treated with oxidative stress generating reagents such as paraquat, salicylic acid, and cadmium, the BcGR overproducing E. coli exhibited a higher level of growth and survival rate than the control E. coli strain, but it was not as high as the E. coli strain transformed with the inducible EcGR. The translated amino acid sequences of BcGR and EcGR share 37.3% identity but all the functionally known important residues are conserved. It appears that eukaryotic BcGR functions in a prokaryotic system by providing protection against oxidative damages in E. coli.
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Affiliation(s)
- Ho-Sung Yoon
- Institute of Agricultural Science and Technology, Kyungpook National University, Daegu 702-701, Republic of Korea
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Teixeira FK, Menezes-Benavente L, Galvão VC, Margis-Pinheiro M. Multigene families encode the major enzymes of antioxidant metabolism in Eucalyptus grandis L. Genet Mol Biol 2005. [DOI: 10.1590/s1415-47572005000400007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Ott T, Fritz E, Polle A, Schützendübel A. Characterisation of antioxidative systems in the ectomycorrhiza-building basidiomycete Paxillus involutus (Bartsch) Fr. and its reaction to cadmium. FEMS Microbiol Ecol 2002; 42:359-66. [DOI: 10.1111/j.1574-6941.2002.tb01025.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Schützendübel A, Polle A. Plant responses to abiotic stresses: heavy metal-induced oxidative stress and protection by mycorrhization. JOURNAL OF EXPERIMENTAL BOTANY 2002. [PMID: 11997381 DOI: 10.1093/jxb/53.372.1351] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The aim of this review is to assess the mode of action and role of antioxidants as protection from heavy metal stress in roots, mycorrhizal fungi and mycorrhizae. Based on their chemical and physical properties three different molecular mechanisms of heavy metal toxicity can be distinguished: (a) production of reactive oxygen species by autoxidation and Fenton reaction; this reaction is typical for transition metals such as iron or copper, (b) blocking of essential functional groups in biomolecules, this reaction has mainly been reported for non-redox-reactive heavy metals such as cadmium and mercury, (c) displacement of essential metal ions from biomolecules; the latter reaction occurs with different kinds of heavy metals. Transition metals cause oxidative injury in plant tissue, but a literature survey did not provide evidence that this stress could be alleviated by increased levels of antioxidative systems. The reason may be that transition metals initiate hydroxyl radical production, which can not be controlled by antioxidants. Exposure of plants to non-redox reactive metals also resulted in oxidative stress as indicated by lipid peroxidation, H(2)O(2) accumulation, and an oxidative burst. Cadmium and some other metals caused a transient depletion of GSH and an inhibition of antioxidative enzymes, especially of glutathione reductase. Assessment of antioxidative capacities by metabolic modelling suggested that the reported diminution of antioxidants was sufficient to cause H(2)O(2) accumulation. The depletion of GSH is apparently a critical step in cadmium sensitivity since plants with improved capacities for GSH synthesis displayed higher Cd tolerance. Available data suggest that cadmium, when not detoxified rapidly enough, may trigger, via the disturbance of the redox control of the cell, a sequence of reactions leading to growth inhibition, stimulation of secondary metabolism, lignification, and finally cell death. This view is in contrast to the idea that cadmium results in unspecific necrosis. Plants in certain mycorrhizal associations are less sensitive to cadmium stress than non-mycorrhizal plants. Data about antioxidative systems in mycorrhizal fungi in pure culture and in symbiosis are scarce. The present results indicate that mycorrhization stimulated the phenolic defence system in the Paxillus-Pinus mycorrhizal symbiosis. Cadmium-induced changes in mycorrhizal roots were absent or smaller than those in non-mycorrhizal roots. These observations suggest that although changes in rhizospheric conditions were perceived by the root part of the symbiosis, the typical Cd-induced stress responses of phenolics were buffered. It is not known whether mycorrhization protected roots from Cd-induced injury by preventing access of cadmium to sensitive extra- or intracellular sites, or by excreted or intrinsic metal-chelators, or by other defence systems. It is possible that mycorrhizal fungi provide protection via GSH since higher concentrations of this thiol were found in pure cultures of the fungi than in bare roots. The development of stress-tolerant plant-mycorrhizal associations may be a promising new strategy for phytoremediation and soil amelioration measures.
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Affiliation(s)
- Andres Schützendübel
- Forstbotanisches Institut, Abteilung I, Forstbotanik und Baumphysiologie, Georg August Universität Göttingen, Büsgenweg 2, 37077 Göttingen, Germany
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