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Conklin PL, Foyer CH, Hancock RD, Ishikawa T, Smirnoff N. Ascorbic acid metabolism and functions. J Exp Bot 2024; 75:2599-2603. [PMID: 38699987 PMCID: PMC11066792 DOI: 10.1093/jxb/erae143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 05/05/2024]
Abstract
This Special Issue was assembled to mark the 25th anniversary of the proposal of the d -mannose/ l -galactose (Smirnoff-Wheeler) ascorbate biosynthesis pathway in plants ( Wheeler et al., 1998 ). The issue aims to assess the current state of knowledge and to identify outstanding questions about ascorbate metabolism and functions in plants.
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Affiliation(s)
- Patricia L Conklin
- Biological Sciences Department, Bowers Hall Rm 240, SUNY Cortland, Cortland, NY 13045, USA
| | - Christine H Foyer
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston B15 2TT, UK
| | - Robert D Hancock
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Takahiro Ishikawa
- Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan
| | - Nicholas Smirnoff
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter EX4 4QD, UK
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2
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Hamada A, Ishikawa T, Maruta T. The demand for ascorbate recycling capacity rises as the ascorbate pool size increases in Arabidopsis plants. Biosci Biotechnol Biochem 2023; 87:1332-1335. [PMID: 37550223 DOI: 10.1093/bbb/zbad107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 07/29/2023] [Indexed: 08/09/2023]
Abstract
Ascorbate recycling is required for high ascorbate accumulation. Hence, when the ascorbate pool size is small, does the demand for ascorbate recycling decrease? We herein investigate the impact of ascorbate recycling capacity on ascorbate pool size in an ascorbate-deficient background. Our findings demonstrate that a smaller ascorbate pool size lowers the need for ascorbate recycling capacity even under light stress.
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Affiliation(s)
- Akane Hamada
- Graduate School of Natural Science and Technology, Shimane University, Matsue, Shimane, Japan
| | - Takahiro Ishikawa
- Graduate School of Natural Science and Technology, Shimane University, Matsue, Shimane, Japan
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
| | - Takanori Maruta
- Graduate School of Natural Science and Technology, Shimane University, Matsue, Shimane, Japan
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
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3
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Fu HY, Wang MW. Ascorbate peroxidase plays an important role in photoacclimation in the extremophilic red alga Cyanidiococcus yangmingshanensis. Front Plant Sci 2023; 14:1176985. [PMID: 37332730 PMCID: PMC10272599 DOI: 10.3389/fpls.2023.1176985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/12/2023] [Indexed: 06/20/2023]
Abstract
Introduction Acidothermophilic cyanidiophytes in natural habitats can survive under a wide variety of light regimes, and the exploration and elucidation of their long-term photoacclimation mechanisms promises great potential for further biotechnological applications. Ascorbic acid was previously identified as an important protectant against high light stress in Galdieria partita under mixotrophic conditions, yet whether ascorbic acid and its related enzymatic reactive oxygen species (ROS) scavenging system was crucial in photoacclimation for photoautotrophic cyanidiophytes was unclear. Methods The significance of ascorbic acid and related ROS scavenging and antioxidant regenerating enzymes in photoacclimation in the extremophilic red alga Cyanidiococcus yangmingshanensis was investigated by measuring the cellular content of ascorbic acid and the activities of ascorbate-related enzymes. Results and discussion Accumulation of ascorbic acid and activation of the ascorbate-related enzymatic ROS scavenging system characterized the photoacclimation response after cells were transferred from a low light condition at 20 μmol photons m-2 s-1 to various light conditions in the range from 0 to 1000 μmol photons m-2 s-1. The activity of ascorbate peroxidase (APX) was most remarkably enhanced with increasing light intensities and illumination periods among the enzymatic activities being measured. Light-dependent regulation of the APX activity was associated with transcriptional regulation of the chloroplast-targeted APX gene. The important role of the APX activity in photoacclimation was evidenced by the effect of the APX inhibitors on the photosystem II activity and the chlorophyll a content under the high light condition at 1000 μmol photons m-2 s-1. Our findings provide a mechanistic explanation for the acclimation of C. yangmingshanensis to a wide range of light regimes in natural habitats.
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4
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Hamada A, Tanaka Y, Ishikawa T, Maruta T. Chloroplast dehydroascorbate reductase and glutathione cooperatively determine the capacity for ascorbate accumulation under photooxidative stress conditions. Plant J 2023; 114:68-82. [PMID: 36694959 DOI: 10.1111/tpj.16117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/16/2023] [Accepted: 01/22/2023] [Indexed: 06/17/2023]
Abstract
Ascorbate is an indispensable redox buffer essential for plant growth and stress acclimation. Its oxidized form, dehydroascorbate (DHA), undergoes rapid degradation unless it is recycled back into ascorbate by glutathione (GSH)-dependent enzymatic or non-enzymatic reactions, with the enzymatic reactions catalyzed by dehydroascorbate reductases (DHARs). Our recent study utilizing an Arabidopsis quadruple mutant (∆dhar pad2), which lacks all three DHARs (∆dhar) and is deficient in GSH (pad2), has posited that these GSH-dependent reactions operate in a complementary manner, enabling a high accumulation of ascorbate under high-light stress. However, as Arabidopsis DHAR functions in the cytosol or chloroplasts, it remained unclear which isoform played a more significant role in cooperation with GSH-dependent non-enzymatic reactions. To further comprehend the intricate network of ascorbate recycling systems in plants, we generated mutant lines lacking cytosolic DHAR1/2 or chloroplastic DHAR3, or both, in another GSH-deficient background (cad2). A comprehensive comparison of ascorbate profiles in these mutants under conditions of photooxidative stress induced by various light intensities or methyl viologen unequivocally demonstrated that chloroplastic DHAR3, but not cytosolic isoforms, works in concert with GSH to accumulate ascorbate. Our findings further illustrate that imbalances between stress intensity and recycling capacity significantly impact ascorbate pool size and tolerance to photooxidative stress. Additionally, it was found that the absence of DHARs and GSH deficiency do not impede ascorbate biosynthesis, at least in terms of transcription or activity of biosynthetic enzymes. This study provides insights into the robustness of ascorbate recycling.
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Affiliation(s)
- Akane Hamada
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504, Japan
| | - Yasuhiro Tanaka
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504, Japan
- Bioresource and Life Sciences, The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553, Japan
| | - Takahiro Ishikawa
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504, Japan
- Bioresource and Life Sciences, The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553, Japan
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504, Japan
| | - Takanori Maruta
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504, Japan
- Bioresource and Life Sciences, The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553, Japan
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504, Japan
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5
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Jardim-Messeder D, de Souza-Vieira Y, Lavaquial LC, Cassol D, Galhego V, Bastos GA, Felix-Cordeiro T, Corrêa RL, Zámocký M, Margis-Pinheiro M, Sachetto-Martins G. Ascorbate-Glutathione Cycle Genes Families in Euphorbiaceae: Characterization and Evolutionary Analysis. Biology (Basel) 2022; 12. [PMID: 36671712 DOI: 10.3390/biology12010019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
Ascorbate peroxidase (APX), Monodehydroascorbate Reductase (MDAR), Dehydroascorbate Reductase (DHAR) and Glutathione Reductase (GR) enzymes participate in the ascorbate-glutathione cycle, which exerts a central role in the antioxidant metabolism in plants. Despite the importance of this antioxidant system in different signal transduction networks related to development and response to environmental stresses, the pathway has not yet been comprehensively characterized in many crop plants. Among different eudicotyledons, the Euphorbiaceae family is particularly diverse with some species highly tolerant to drought. Here the APX, MDAR, DHAR, and GR genes in Ricinus communis, Jatropha curcas, Manihot esculenta, and Hevea brasiliensis were identified and characterized. The comprehensive phylogenetic and genomic analyses allowed the classification of the genes into different classes, equivalent to cytosolic, peroxisomal, chloroplastic, and mitochondrial enzymes, and revealed the duplication events that contribute to the expansion of these families within plant genomes. Due to the high drought stress tolerance of Ricinus communis, the expression patterns of ascorbate-glutathione cycle genes in response to drought were also analyzed in leaves and roots, indicating a differential expression during the stress. Altogether, these data contributed to the characterization of the expression pattern and evolutionary analysis of these genes, filling the gap in the proposed functions of core components of the antioxidant mechanism during stress response in an economically relevant group of plants.
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Terzaghi M, De Tullio MC. The perils of planning strategies to increase vitamin C content in plants: Beyond the hype. Front Plant Sci 2022; 13:1096549. [PMID: 36600921 PMCID: PMC9806220 DOI: 10.3389/fpls.2022.1096549] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Ever since the identification of vitamin C (ascorbic acid, AsA) as an essential molecule that humans cannot synthesize on their own, finding adequate dietary sources of AsA became a priority in nutrition research. Plants are the main producers of AsA for humans and other non-synthesizing animals. It was immediately clear that some plant species have more AsA than others. Further studies evidenced that AsA content varies in different plant organs, in different developmental stages/environmental conditions and even within different cell compartments. With the progressive discovery of the genes of the main (Smirnoff-Wheeler) and alternative pathways coding for the enzymes involved in AsA biosynthesis in plants, the simple overexpression of those genes appeared a suitable strategy for boosting AsA content in any plant species or organ. Unfortunately, overexpression experiments mostly resulted in limited, if any, AsA increase, apparently due to a tight regulation of the biosynthetic machinery. Attempts to identify regulatory steps in the pathways that could be manipulated to obtain unlimited AsA production were also less successful than expected, confirming the difficulties in "unleashing" AsA synthesis. A different approach to increase AsA content has been the overexpression of genes coding for enzymes catalyzing the recycling of the oxidized forms of vitamin C, namely monodehydroascorbate and dehydroascorbate reductases. Such approach proved mostly effective in making the overexpressors apparently more resistant to some forms of environmental stress, but once more did not solve the issue of producing massive AsA amounts for human diet. However, it should also be considered that a hypothetical unlimited increase in AsA content is likely to interfere with plant development, which is in many ways regulated by AsA availability itself. The present review article aims at summarizing the many attempts made so far to improve AsA production/content in plants, evidencing the most promising ones, and at providing information about the possible unexpected consequences of a pure biotechnological approach not keeping into account the peculiar features of the AsA system in plants.
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Affiliation(s)
- Mattia Terzaghi
- Department of Biosciences, Biotechnologies and Environment, University of Bari "Aldo Moro", Bari, Italy
| | - Mario C. De Tullio
- Department of Earth and Geoenvironmental Sciences, University of Bari "Aldo Moro", Bari, Italy
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7
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Tanaka M, Takahashi R, Hamada A, Terai Y, Ogawa T, Sawa Y, Ishikawa T, Maruta T. Distribution and Functions of Mono dehydroascorbate Reductases in Plants: Comprehensive Reverse Genetic Analysis of Arabidopsis thaliana Enzymes. Antioxidants (Basel) 2021; 10:antiox10111726. [PMID: 34829597 PMCID: PMC8615211 DOI: 10.3390/antiox10111726] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/22/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
Monodehydroascorbate reductase (MDAR) is an enzyme involved in ascorbate recycling. Arabidopsis thaliana has five MDAR genes that encode two cytosolic, one cytosolic/peroxisomal, one peroxisomal membrane-attached, and one chloroplastic/mitochondrial isoform. In contrast, tomato plants possess only three enzymes, lacking the cytosol-specific enzymes. Thus, the number and distribution of MDAR isoforms differ according to plant species. Moreover, the physiological significance of MDARs remains poorly understood. In this study, we classify plant MDARs into three classes: class I, chloroplastic/mitochondrial enzymes; class II, peroxisomal membrane-attached enzymes; and class III, cytosolic/peroxisomal enzymes. The cytosol-specific isoforms form a subclass of class III and are conserved only in Brassicaceae plants. With some exceptions, all land plants and a charophyte algae, Klebsormidium flaccidum, contain all three classes. Using reverse genetic analysis of Arabidopsis thaliana mutants lacking one or more isoforms, we provide new insight into the roles of MDARs; for example, (1) the lack of two isoforms in a specific combination results in lethality, and (2) the role of MDARs in ascorbate redox regulation in leaves can be largely compensated by other systems. Based on these findings, we discuss the distribution and function of MDAR isoforms in land plants and their cooperation with other recycling systems.
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Affiliation(s)
- Mio Tanaka
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (M.T.); (A.H.); (T.O.); (T.I.)
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (R.T.); (Y.T.); (Y.S.)
| | - Ryuki Takahashi
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (R.T.); (Y.T.); (Y.S.)
| | - Akane Hamada
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (M.T.); (A.H.); (T.O.); (T.I.)
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (R.T.); (Y.T.); (Y.S.)
| | - Yusuke Terai
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (R.T.); (Y.T.); (Y.S.)
| | - Takahisa Ogawa
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (M.T.); (A.H.); (T.O.); (T.I.)
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (R.T.); (Y.T.); (Y.S.)
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan
| | - Yoshihiro Sawa
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (R.T.); (Y.T.); (Y.S.)
| | - Takahiro Ishikawa
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (M.T.); (A.H.); (T.O.); (T.I.)
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (R.T.); (Y.T.); (Y.S.)
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan
| | - Takanori Maruta
- Graduate School of Natural Science and Technology, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (M.T.); (A.H.); (T.O.); (T.I.)
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan; (R.T.); (Y.T.); (Y.S.)
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Shimane, Japan
- Correspondence: ; Tel.: +81-882-32-6585
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8
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Ding H, Wang B, Han Y, Li S. The pivotal function of dehydroascorbate reductase in glutathione homeostasis in plants. J Exp Bot 2020; 71:3405-3416. [PMID: 32107543 DOI: 10.1093/jxb/eraa107] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 02/25/2020] [Indexed: 05/20/2023]
Abstract
Under natural conditions, plants are exposed to various abiotic and biotic stresses that trigger rapid changes in the production and removal of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). The ascorbate-glutathione pathway has been recognized to be a key player in H2O2 metabolism, in which reduced glutathione (GSH) regenerates ascorbate by reducing dehydroascorbate (DHA), either chemically or via DHA reductase (DHAR), an enzyme belonging to the glutathione S-transferase (GST) superfamily. Thus, DHAR has been considered to be important in maintaining the ascorbate pool and its redox state. Although some GSTs and peroxiredoxins may contribute to GSH oxidation, analysis of Arabidopsis dhar mutants has identified the key role of DHAR in coupling H2O2 to GSH oxidation. The reaction of DHAR has been proposed to proceed by a ping-pong mechanism, in which binding of DHA to the free reduced form of the enzyme is followed by binding of GSH. Information from crystal structures has shed light on the formation of sulfenic acid at the catalytic cysteine of DHAR that occurs with the reduction of DHA. In this review, we discuss the molecular properties of DHAR and its importance in coupling the ascorbate and glutathione pools with H2O2 metabolism, together with its functions in plant defense, growth, and development.
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Affiliation(s)
- Haiyan Ding
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Bipeng Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Yi Han
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, China
- Engineering Research Center of Bio-process, Ministry of Education, Hefei University of Technology, Hefei, China
| | - Shengchun Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
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Loi M, Leonardis S, Mulè G, Logrieco AF, Paciolla C. A Novel and Potentially Multifaceted Dehydroascorbate Reductase Increasing theAntioxidant Systems Is Induced by Beauvericinin Tomato. Antioxidants (Basel) 2020; 9:E435. [PMID: 32429369 DOI: 10.3390/antiox9050435] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/11/2022] Open
Abstract
Dehydroascorbate reductases (DHARs) are important enzymes that reconvert the dehydroascorbic acid (DHA) into ascorbic acid (ASC). They are involved in the plant response to oxidative stress, such as that induced by the mycotoxin beauvericin (BEA). Tomato plants were treated with 50 µM of BEA; the main antioxidant compounds and enzymes were evaluated. DHARs were analyzed in the presence of different electron donors by native and denaturing electrophoresis as well as by western blot and mass spectrometry to identify a novel induced protein with DHAR activity. Kinetic parameters for dehydroascorbate (DHA) and glutathione (GSH) were also determined. The novel DHAR was induced after BEA treatment. It was GSH-dependent and possessed lower affinity to DHA and GSH than the classical DHARs. Interestingly, the mass spectrometry analysis of the main band appearing on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed a chloroplast sedoheptulose 1,7-bisphosphatase, a key enzyme of the Calvin cycle, and a chloroplast mRNA-binding protein, suggesting that the DHA reducing capacity could be a side activity or the novel DHAR could be part of a protein complex. These results shed new light on the ascorbate-glutathione regulation network under oxidative stress and may represent a new way to increase the plant antioxidant defense system, plant nutraceutical value, and the health benefits of plant consumption.
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Kim YS, Park SI, Kim JJ, Boyd JS, Beld J, Taton A, Lee KI, Kim IS, Golden JW, Yoon HS. Expression of Heterologous OsDHAR Gene Improves Glutathione (GSH)-Dependent Antioxidant System and Maintenance of Cellular Redox Status in Synechococcus elongatus PCC 7942. Front Plant Sci 2020; 11:231. [PMID: 32194605 PMCID: PMC7063034 DOI: 10.3389/fpls.2020.00231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 02/14/2020] [Indexed: 06/10/2023]
Abstract
An excess of reactive oxygen species (ROS) can cause severe oxidative damage to cellular components in photosynthetic cells. Antioxidant systems, such as the glutathione (GSH) pools, regulate redox status in cells to guard against such damage. Dehydroascorbate reductase (DHAR, EC 1.8.5.1) catalyzes the glutathione-dependent reduction of oxidized ascorbate (dehydroascorbate) and contains a redox active site and glutathione binding-site. The DHAR gene is important in biological and abiotic stress responses involving reduction of the oxidative damage caused by ROS. In this study, transgenic Synechococcus elongatus PCC 7942 (TA) was constructed by cloning the Oryza sativa L. japonica DHAR (OsDHAR) gene controlled by an isopropyl β-D-1-thiogalactopyranoside (IPTG)-inducible promoter (Ptrc) into the cyanobacterium to study the functional activities of OsDHAR under oxidative stress caused by hydrogen peroxide exposure. OsDHAR expression increased the growth of S. elongatus PCC 7942 under oxidative stress by reducing the levels of hydroperoxides and malondialdehyde (MDA) and mitigating the loss of chlorophyll. DHAR and glutathione S-transferase activity were higher than in the wild-type S. elongatus PCC 7942 (WT). Additionally, overexpression of OsDHAR in S. elongatus PCC 7942 greatly increased the glutathione (GSH)/glutathione disulfide (GSSG) ratio in the presence or absence of hydrogen peroxide. These results strongly suggest that DHAR attenuates deleterious oxidative effects via the glutathione (GSH)-dependent antioxidant system in cyanobacterial cells. The expression of heterologous OsDHAR in S. elongatus PCC 7942 protected cells from oxidative damage through a GSH-dependent antioxidant system via GSH-dependent reactions at the redox active site and GSH binding site residues during oxidative stress.
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Affiliation(s)
- Young-Saeng Kim
- Research Institute for Dok-do and Ulleung-do, Kyungpook National University, Daegu, South Korea
| | - Seong-Im Park
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, South Korea
- Department of Biology, Kyungpook National University, Daegu, South Korea
| | - Jin-Ju Kim
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, South Korea
- Department of Biology, Kyungpook National University, Daegu, South Korea
| | - Joseph S. Boyd
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Joris Beld
- Department of Microbiology and Immunology, College of Medicine, Drexel University, Philadelphia, PA, United States
| | - Arnaud Taton
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Kyoung-In Lee
- Biotechnology Industrialization Center, Dongshin University, Naju, South Korea
| | - Il-Sup Kim
- Advanced Bio Resource Research Center, Kyungpook National University, Daegu, South Korea
| | - James W. Golden
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Ho-Sung Yoon
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, South Korea
- Department of Biology, Kyungpook National University, Daegu, South Korea
- Advanced Bio Resource Research Center, Kyungpook National University, Daegu, South Korea
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11
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Dias MC, Pinto DCGA, Freitas H, Santos C, Silva AMS. The antioxidant system in Olea europaea to enhanced UV-B radiation also depends on flavonoids and secoiridoids. Phytochemistry 2020; 170:112199. [PMID: 31759269 DOI: 10.1016/j.phytochem.2019.112199] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 05/08/2023]
Abstract
The Mediterranean crop Olea europaea is often exposed to high UV-B irradiation conditions. To understand how this species modulates its enzymatic and non-enzymatic antioxidant system under high UV-B radiation, young O. europaea plants (cultivar "Galega Vulgar") were exposed, for five days, to UV-B radiation (6.5 kJ m-2 d-1 and 12.4 kJ m-2 d-1). Our data indicate that UV-doses slightly differ in the modulation of the antioxidant protective mechanisms. Particularly, superoxide dismutase (SOD), guaiacol peroxidase (GPox) and catalase (CAT) activities increased contributing to H2O2 homeostasis, being more solicited by higher UV-B doses. Also, glutathione reductase (Gr) activity, ascorbate (AsA) and reduced glutathione (GSH) pools increased particularly under the highest dose, suggesting a higher mobilization of the antioxidant system in this dose. The leaf metabolites' profile of this cultivar was analysed by UHPLC-MS. Interestingly, high levels of verbascoside were found, followed by oleuropein and luteolin-7-O-glucoside. Both UV-B treatments affected mostly less abundant flavonoids (decreasing 4'-methoxy luteolin and 4' or 3'-methoxy luteolin glucoside) and hydroxycinnamic acid derivatives (HCAds, increasing β-hydroxyverbascoside). These changes show not only different mobilization with the UV-intensity, but also reinforce for the first time the protective roles of these minor compounds against UV-B, as reactive oxygen species (ROS) scavengers and UV-B shields, in complement with other antioxidant systems (e.g. AsA/GSH cycle), particularly for high UV-B doses. Secoiridoids also standout in the response to both UV-B doses, with decreases of oleuropein and increases 2''-methoxyoleuropein. Being oleuropein an abundant compound, data suggest that secoiridoids play a more important role than flavonoids and HCAds, in O. europaea protection against UV-B, possibly by acting as signalling molecules and ROS scavengers. This is the first report on the influence of UV-B radiation on the secoiridoid oleuropein, and provides a novel insight to the role of this compound in the O. europaea antioxidant defence mechanisms.
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Affiliation(s)
- Maria Celeste Dias
- Department of Life Sciences & CFE, Faculty of Sciences and Technologies, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal; QOPNA & LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal.
| | - Diana C G A Pinto
- QOPNA & LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Helena Freitas
- Department of Life Sciences & CFE, Faculty of Sciences and Technologies, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - Conceição Santos
- Department of Biology & LAQV/REQUIMTE, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007, Porto, Portugal
| | - Artur M S Silva
- QOPNA & LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal
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12
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Xing C, Liu Y, Zhao L, Zhang S, Huang X. A novel MYB transcription factor regulates ascorbic acid synthesis and affects cold tolerance. Plant Cell Environ 2019; 42:832-845. [PMID: 29929211 DOI: 10.1111/pce.13387] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/19/2018] [Accepted: 06/13/2018] [Indexed: 05/18/2023]
Abstract
Dehydroascorbate reductase (DHAR) plays an important role in stress responses, but the transcriptional regulation of DHAR in response to abiotic stress is still poorly understood. In this study, we isolated a novel R2R3-type MYB transcription factor from Pyrus betulaefolia by yeast one-hybrid screening, designated as PbrMYB5. PbrMYB5 was localized in the nucleus and could bind specifically to the promoter of PbrDHAR2. PbrMYB5 was greatly induced by cold and salt but slightly by dehydration. Overexpression of PbrMYB5 in tobacco conferred enhanced tolerance to chilling stresses, whereas down-regulation of PbrMYB5 in P. betulaefolia by virus-induced gene silencing resulted in elevated chilling sensitivity. Transgenic tobacco exhibited higher expression levels of NtDHAR2 and accumulated larger amount of ascorbic acid (AsA) than the wild-type plants. Virus-induced gene silencing of PbrMYB5 in P. betulaefolia down-regulated PbrDHAR2 abundance and decreased AsA level, accompanied by an increased sensitivity to the chilling stress. Taken together, these results demonstrated that PbrMYB5 was an activator of AsA biosynthesis and may play a positive role in chilling tolerance, at least in part, due to the modulation of AsA synthesis by regulating the PbrDHAR2 expression.
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Affiliation(s)
- Caihua Xing
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Yue Liu
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Liangyi Zhao
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Shaoling Zhang
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Xiaosan Huang
- College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
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13
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Harre NT, Nie H, Jiang Y, Young BG. Differential antioxidant enzyme activity in rapid-response glyphosate-resistant Ambrosia trifida. Pest Manag Sci 2018; 74:2125-2132. [PMID: 29532632 DOI: 10.1002/ps.4909] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/03/2018] [Accepted: 03/05/2018] [Indexed: 02/28/2024]
Abstract
BACKGROUND The giant ragweed (Ambrosia trifida L.) rapid-response (RR) biotype exhibits a sacrificial form of glyphosate resistance whereby an oxidative burst in mature leaves results in foliage loss, while juvenile leaves remain uninjured. This work investigated the safening capacity of antioxidant enzymes in RR juvenile leaves following glyphosate treatment and examined cross tolerance to paraquat. RESULTS Basal antioxidant enzyme activities were similar between glyphosate-susceptible (GS) and RR biotypes. Lipid peroxidation was first detected in RR mature leaves at 8 h after treatment (HAT) and by 32 HAT was 5.3 and 21.1 times greater than that in RR juvenile leaves and GS leaves, respectively. Preceding lipid peroxidation in the RR biotype at 2 and 4 HAT, the only increase in enzymatic activity was observed in ascorbate-glutathione cycle enzymes in RR juvenile leaves, particularly ascorbate peroxidase, dehydroascorbate reductase, and glutathione reductase. Sensitivity to paraquat was similar between biotypes. CONCLUSION The RR biotype is not inherently more tolerant to oxidative stress. The difference in tissue damage between RR juvenile and mature leaves following glyphosate treatment is attributable at least partially to the transient increase in antioxidant enzyme expression in juvenile leaves (0-8 HAT), but may also be attributable to lower overall RR induction in juvenile leaves compared with mature leaves. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Nick T Harre
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Haozhen Nie
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Yiwei Jiang
- Department of Agronomy, Purdue University, West Lafayette, IN, USA
| | - Bryan G Young
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
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14
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Fujiwara A, Togawa S, Hikawa T, Matsuura H, Masuta C, Inukai T. Ascorbic acid accumulates as a defense response to Turnip mosaic virus in resistant Brassica rapa cultivars. J Exp Bot 2016; 67:4391-402. [PMID: 27255930 PMCID: PMC5301938 DOI: 10.1093/jxb/erw223] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We initially observed that Brassica rapa cultivars containing the Turnip mosaic virus (TuMV) resistance gene, Rnt1-1, accumulated a high level of endogenous ascorbic acid (AS) and dehydroascobic acid (DHA) when infected with TuMV. We here hypothesized a possible contribution of an elevated level of AS+DHA (TAA) to the Rnt1-1-mediated resistance, and conducted a series of experiments using B. rapa and Arabidopsis plants. The application of l-galactose (the key substrate in AS synthesis) to a susceptible cultivar could increase the TAA level ~2-fold, and simultaneously lead to some degree of enhanced viral resistance. To confirm some positive correlation between TAA levels and viral resistance, we analyzed two Arabidopsis knockout mutants (ao and vtc1) in the AS pathways; the TAA levels were significantly increased and decreased in ao and vtc1 plants, respectively. While the ao plants showed enhanced resistance to TuMV, vtc1 plants were more susceptible than the control, supporting our hypothesis. When we analyzed the expression profiles of the genes involved in the AS pathways upon TuMV infection, we found that the observed TAA increase was mainly brought about by the reduction of AS oxidation and activation of AS recycling. We then investigated the secondary signals that regulate endogenous TAA levels in response to viral infection, and found that jasmonic acid (JA) might play an important role in TAA accumulation. In conclusion, we reason that the elevated TAA accumulation in B. rapa plants would be at least partly mediated by the JA-dependent signaling pathway and may significantly contribute to viral resistance.
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Affiliation(s)
- Ayaka Fujiwara
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Satoko Togawa
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Takahiro Hikawa
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Hideyuki Matsuura
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Chikara Masuta
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Tsuyoshi Inukai
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
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Noshi M, Hatanaka R, Tanabe N, Terai Y, Maruta T, Shigeoka S. Redox regulation of ascorbate and glutathione by a chloroplastic dehydroascorbate reductase is required for high-light stress tolerance in Arabidopsis. Biosci Biotechnol Biochem 2016; 80:870-7. [PMID: 26927949 DOI: 10.1080/09168451.2015.1135042] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chloroplasts are a significant site for reactive oxygen species production under illumination and, thus, possess a well-organized antioxidant system involving ascorbate. Ascorbate recycling occurs in different manners in this system, including a dehydroascorbate reductase (DHAR) reaction. We herein investigated the physiological significance of DHAR3 in photo-oxidative stress tolerance in Arabidopsis. GFP-fused DHAR3 protein was targeted to chloroplasts in Arabidopsis leaves. A DHAR3 knockout mutant exhibited sensitivity to high light (HL). Under HL, the ascorbate redox states were similar in mutant and wild-type plants, while total ascorbate content was significantly lower in the mutant, suggesting that DHAR3 contributes, at least to some extent, to ascorbate recycling. Activation of monodehydroascorbate reductase occurred in dhar3 mutant, which might compensate for the lack of DHAR3. Interestingly, glutathione oxidation was consistently inhibited in dhar3 mutant. These findings indicate that DHAR3 regulates both ascorbate and glutathione redox states to acclimate to HL.
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Affiliation(s)
- Masahiro Noshi
- a Faculty of Agriculture, Department of Advanced Bioscience , Kinki University , Nara , Japan
| | - Risa Hatanaka
- a Faculty of Agriculture, Department of Advanced Bioscience , Kinki University , Nara , Japan
| | - Noriaki Tanabe
- a Faculty of Agriculture, Department of Advanced Bioscience , Kinki University , Nara , Japan
| | - Yusuke Terai
- b Faculty of Life and Environmental Science, Department of Life Science and Biotechnology , Shimane University , Matsue , Japan
| | - Takanori Maruta
- b Faculty of Life and Environmental Science, Department of Life Science and Biotechnology , Shimane University , Matsue , Japan
| | - Shigeru Shigeoka
- a Faculty of Agriculture, Department of Advanced Bioscience , Kinki University , Nara , Japan
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16
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Do H, Kim IS, Kim YS, Shin SY, Kim JJ, Mok JE, Park SI, Wi AR, Park H, Kim HW, Yoon HS, Lee JH. Crystallization and preliminary X-ray crystallographic studies of dehydroascorbate reductase (DHAR) from Oryza sativa L. japonica. Acta Crystallogr F Struct Biol Commun 2014; 70:781-5. [PMID: 24915093 DOI: 10.1107/s2053230x14009133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 04/22/2014] [Indexed: 11/10/2022]
Abstract
Dehydroascorbate reductase from Oryza sativa L. japonica (OsDHAR), a key enzyme in the regeneration of vitamin C, maintains reduced pools of ascorbic acid to detoxify reactive oxygen species. In previous studies, the overexpression of OsDHAR in transgenic rice increased grain yield and biomass as well as the amount of ascorbate, suggesting that ascorbate levels are directly associated with crop production in rice. Hence, it has been speculated that the increased level of antioxidants generated by OsDHAR protects rice from oxidative damage and increases the yield of rice grains. However, the crystal structure and detailed mechanisms of this important enzyme need to be further elucidated. In this study, recombinant OsDHAR protein was purified and crystallized using the sitting-drop vapour-diffusion method at pH 8.0 and 298 K. Plate-shaped crystals were obtained using 0.15 M potassium bromide, 30%(w/v) PEG MME 2000 as a precipitant, and the crystals diffracted to a resolution of 1.9 Å on beamline 5C at the Pohang Accelerator Laboratory. The X-ray diffraction data indicated that the crystal contained one OsDHAR molecule in the asymmetric unit and belonged to space group P2₁ with unit-cell parameters a=47.03, b=48.38, c=51.83 Å, β=107.41°.
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Affiliation(s)
- Hackwon Do
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea
| | - Il-Sup Kim
- Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Young-Saeng Kim
- Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Sun-Young Shin
- Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Jin-Ju Kim
- Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Ji-Eun Mok
- Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Seong-Im Park
- Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Ah Ram Wi
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea
| | - Hyun Park
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea
| | - Han-Woo Kim
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea
| | - Ho-Sung Yoon
- Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Jun Hyuck Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea
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17
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Xin X, Tian Q, Yin G, Chen X, Zhang J, Ng S, Lu X. Reduced mitochondrial and ascorbate-glutathione activity after artificial ageing in soybean seed. J Plant Physiol 2014. [PMID: 24331429 DOI: 10.1016/j.jplph.2013.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The effect of artificial ageing on the relationship between mitochondrial activities and the antioxidant system was studied in soybean seeds (Glycine max L. cv. Zhongdou No. 27). Ageing seeds for 18d and 41d at 40°C reduced germination from 99% to 52% and 0%, respectively. In comparison to the control, malondialdehyde content and leachate conductivity in aged seeds increased and were associated with membrane damage. Transmission electron microscopy and Percoll density gradient centrifugation showed that aged seeds mainly contained poorly developed mitochondria in which respiration and marker enzymes activities were significantly reduced. Heavy mitochondria isolated from the interface of the 21% and 40% Percoll were analyzed. Mitochondrial antioxidant enzymes activities including superoxide dismutase, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase were significantly reduced in aged seeds. A decrease in total ascorbic acid (ASC) and glutathione (GSH) content as well as the reduced/oxidized ratio of ASC and GSH in mitochondria with prolonged ageing showed that artificial ageing reduced ASC-GSH cycle activity. These results suggested an elevated reactive oxygen species (ROS) level in the aged seeds, which was confirmed by measurements of superoxide radical and hydrogen peroxide levels. We conclude that mitochondrial dysfunction in artificially aged seeds is due to retarded mitochondrial and ASC-GSH cycle activity and elevated ROS accumulation.
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Affiliation(s)
- Xia Xin
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Qian Tian
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Shandong Center of Crop Germplasm Resources, Jinan 250100, China
| | - Guangkun Yin
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaoling Chen
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jinmei Zhang
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Sophia Ng
- Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, 310058 Hangzhou, China; Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley 6009, WA, Australia
| | - Xinxiong Lu
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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18
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Xin X, Tian Q, Yin G, Chen X, Zhang J, Ng S, Lu X. Reduced mitochondrial and ascorbate-glutathione activity after artificial ageing in soybean seed. J Plant Physiol 2014; 171:140-7. [PMID: 24331429 DOI: 10.1016/j.jplph.2013.09.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 09/02/2013] [Accepted: 09/02/2013] [Indexed: 05/07/2023]
Abstract
The effect of artificial ageing on the relationship between mitochondrial activities and the antioxidant system was studied in soybean seeds (Glycine max L. cv. Zhongdou No. 27). Ageing seeds for 18d and 41d at 40°C reduced germination from 99% to 52% and 0%, respectively. In comparison to the control, malondialdehyde content and leachate conductivity in aged seeds increased and were associated with membrane damage. Transmission electron microscopy and Percoll density gradient centrifugation showed that aged seeds mainly contained poorly developed mitochondria in which respiration and marker enzymes activities were significantly reduced. Heavy mitochondria isolated from the interface of the 21% and 40% Percoll were analyzed. Mitochondrial antioxidant enzymes activities including superoxide dismutase, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase were significantly reduced in aged seeds. A decrease in total ascorbic acid (ASC) and glutathione (GSH) content as well as the reduced/oxidized ratio of ASC and GSH in mitochondria with prolonged ageing showed that artificial ageing reduced ASC-GSH cycle activity. These results suggested an elevated reactive oxygen species (ROS) level in the aged seeds, which was confirmed by measurements of superoxide radical and hydrogen peroxide levels. We conclude that mitochondrial dysfunction in artificially aged seeds is due to retarded mitochondrial and ASC-GSH cycle activity and elevated ROS accumulation.
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Affiliation(s)
- Xia Xin
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Qian Tian
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Shandong Center of Crop Germplasm Resources, Jinan 250100, China
| | - Guangkun Yin
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaoling Chen
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jinmei Zhang
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Sophia Ng
- Joint Research Laboratory in Genomics and Nutriomics, College of Life Sciences, Zhejiang University, 310058 Hangzhou, China; Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley 6009, WA, Australia
| | - Xinxiong Lu
- National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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19
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Ren J, Chen Z, Duan W, Song X, Liu T, Wang J, Hou X, Li Y. Comparison of ascorbic acid biosynthesis in different tissues of three non-heading Chinese cabbage cultivars. Plant Physiol Biochem 2013; 73:229-36. [PMID: 24157701 DOI: 10.1016/j.plaphy.2013.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 10/02/2013] [Indexed: 05/26/2023]
Abstract
Ascorbic acid (L-AsA) is an important antioxidant in plants and humans. Vegetables are one of the main sources of ascorbic acid for humans. For instance, non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) is considered as one of the most important vegetables in south China. To elucidate the mechanism by which AsA accumulates, we systematically investigated the expression profiles of D-mannose/L-galactose pathway-related genes. We also investigated the recycling-related genes and AsA contents in different tissues of three non-heading Chinese cabbage cultivars, 'Suzhouqing', 'Wutacai' and 'Erqing' containing different amounts of AsA. Our results showed that six genes [D-mannose-6-phosphate isomerase 1 (PMI1), GDP-L-galactose phosphorylase 1 (GGP1), GGP2, GGP4, GDP-mannose-3', 5'-epimerase1 (GME1), and GME2] were expressed at high level and ascorbate oxidase (AAO) was expressed at low level. This expression pattern contributes, at least partially, to higher AsA accumulation in the leaves and petioles than in the roots. Eight genes (PMI1, GME, GGP, L-galactose-1-phosphate phosphatase, L-galactose dehydrogenase, L-galactono-1, 4-lactone dehydrogenase, monodehydroascorbate reductase 1, and glutathione reductase1) were also expressed at high level; AAO and ascorbate peroxidase (APX) were expressed at low level. This expression pattern may similarly contribute to higher AsA accumulation in 'Wutacai' and 'Suzhouqing' than in 'Erqing'. Therefore, the high expression levels of PMI, GME, and GGP and the low expression level of AAO contributed to the high AsA accumulation in non-heading Chinese cabbage.
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Affiliation(s)
- Jun Ren
- Horticultural Department, Nanjing Agricultural University, Nanjing 210095, China; State Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing 210095, China; Key Laboratory of Southern Vegetable Crop Genetic Improvement, Ministry of Agriculture, Nanjing 210095, China
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20
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Zhu JJ, Li YR, Liao JX. Involvement of anthocyanins in the resistance to chilling-induced oxidative stress in Saccharum officinarum L. leaves. Plant Physiol Biochem 2013; 73:427-33. [PMID: 23932150 DOI: 10.1016/j.plaphy.2013.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 07/17/2013] [Indexed: 05/06/2023]
Abstract
Whether anthocyanins elevate resistance to chilling-induced oxidative stress in Saccharum officinarum L. cv Badila seedlings is investigated. Plants with four fully expanded leaves were exposed to chilling stress (8 °C/4 °C, 11 h photoperiod) for 3 days and then transferred to rewarming condition (25 °C/20 °C, 11 h photoperiod) for another 2 days. At the end of the chilling period, H2O2 and superoxide radical (O2-) levels increased sharply and were near the same in the central (CL) and the final fully expanded leaves (FL). Moreover, the degree of chilling injury indicated by malonaldehyde concentration and percent of ion leakage also was near the same. Most of the tested parameters returned near to the control level after 2 days of rewarming. With further analyzing, we found that superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11), glutathione reductase (EC 1.6.4.2) activities increased much higher and catalase (EC 1.11.1.6) activity and ascorbate/dehydroascorbate ratio decreased much more in FL than CL in response to chilling. However, anthocyanins concentration coupling with glutathione/oxidized glutathione increased much higher in CL than FL under chilling stress. These finds suggest that anthocyanins at least partially compensate the relative deficiency of antioxidants in CL compared with FL. α,α-Diphenyl-β-picrylhydrazyl assays further confirmed this idea. The relationships between anthocyanins and antioxidants were analyzed and the possible mechanisms of the affection of anthocyanins on antioxidant metabolism were discussed.
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Affiliation(s)
- Jun-Jie Zhu
- Sugarcane Research Center of Chinese Academy of Agricultural Sciences Research, Nanning, Guangxi 530007, China; Guangxi Academy of Agricultural Sciences, Nanning, Guangxi 530007, China.
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21
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Shin SY, Kim MH, Kim YH, Park HM, Yoon HS. Co-expression of mono dehydroascorbate reductase and dehydroascorbate reductase from Brassica rapa effectively confers tolerance to freezing-induced oxidative stress. Mol Cells 2013; 36:304-15. [PMID: 24170089 PMCID: PMC3887988 DOI: 10.1007/s10059-013-0071-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 08/20/2013] [Accepted: 08/26/2013] [Indexed: 01/01/2023] Open
Abstract
Plants are exposed to various environmental stresses and have therefore developed antioxidant enzymes and molecules to protect their cellular components against toxicity derived from reactive oxygen species (ROS). Ascorbate is a very important antioxidant molecule in plants, and monodehydroascorbate reductase (MDHAR; EC 1.6.5.4) and dehydroascorbate reductase (DHAR; EC 1.8.5.1) are essential to regeneration of ascorbate for maintenance of ROS scavenging ability. The MDHAR and DHAR genes from Brassica rapa were cloned, transgenic plants overexpressing either BrMDHAR and BrDHAR were established, and then, each transgenic plant was hybridized to examine the effects of co-expression of both genes conferring tolerance to freezing. Transgenic plants co-overexpressing BrMDHAR and BrDHAR showed activated expression of relative antioxidant enzymes, and enhanced levels of glutathione and phenolics under freezing condition. Then, these alteration caused by co-expression led to alleviated redox status and lipid peroxidation and consequently conferred improved tolerance against severe freezing stress compared to transgenic plants overexpressing single gene. The results of this study suggested that although each expression of BrMDHAR or BrDHAR was available to according tolerance to freezing, the simultaneous expression of two genes generated synergistic effects conferring improved tolerance more effectively even severe freezing.
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Affiliation(s)
| | | | | | | | - Ho-Sung Yoon
- Advanced Bio-resource Research Center/Department of Biology, Kyungpook National University, Daegu 702-701, Korea
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Xu Y, Zhu X, Chen Y, Gong Y, Liu L. Expression profiling of genes involved in ascorbate biosynthesis and recycling during fleshy root development in radish. Plant Physiol Biochem 2013; 70:269-277. [PMID: 23800662 DOI: 10.1016/j.plaphy.2013.05.041] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 05/23/2013] [Indexed: 06/02/2023]
Abstract
Ascorbate is a primary antioxidant and an essential enzyme cofactor in plants, which has an important effect on the development of plant root system. To investigate the molecular mechanisms of ascorbate accumulation during root development and reveal the key genes of the ascorbate biosynthesis and recycling pathways, the expression of 16 related genes together with ascorbate abundance were analyzed in the flesh and skin of radish (Raphanus sativus L.) fleshy root. The content of ascorbate decreased with root growth in both the flesh and skin. Expression of GDP-d-mannose pyrophosphorylase, GDP-d-mannose-3',5'-epimerase and d-galacturonate reductase were also decreased and correlated with ascorbate levels in the flesh. In the skin, the expression of GDP-d-mannose pyrophosphorylase and l-galactose dehydrogenase was correlated with ascorbate levels. These results suggested that ascorbate accumulation is affected mainly by biosynthesis rather than recycling in radish root, and the l-galactose pathway may be the major biosynthetic route of ascorbate, and moreover, the salvage pathway may also contribute to ascorbate accumulation. The data suggested that GDP-d-mannose pyrophosphorylase could play an important role in the regulation of ascorbate accumulation during radish fleshy taproot development.
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Affiliation(s)
- Yao Xu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China), Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, PR China
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Sayantan D. Amendment in phosphorus levels moderate the chromium toxicity in Raphanus sativus L. as assayed by antioxidant enzymes activities. Ecotoxicol Environ Saf 2013; 95:161-170. [PMID: 23810367 DOI: 10.1016/j.ecoenv.2013.05.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 05/18/2013] [Accepted: 05/29/2013] [Indexed: 06/02/2023]
Abstract
Chromium (Z=24), a d-block element, is a potent carcinogen, whereas phosphorus is an essential and limiting nutrient for the plant growth and development. This study undertakes the role of phosphorus in moderating the chromium toxicity in Raphanus sativus L., as both of them compete with each other during the uptake process. Two-factor complete randomized experiment (5 chromium × 5 phosphorus concentrations) was conducted for twenty eight days in green house. The individuals of R. sativus were grown in pots supplied with all essential nutrients. The toxic effects of chromium and the moderation of toxicity due to phosphorus amendment were determined as accumulation of chromium, nitrogen, phosphorus in root tissues and their effects were also examined in the changes in biomass, chlorophyll and antioxidant enzyme levels. Cr and N accumulation were almost doubled at the highest concentration of Cr supply, without any P amendment, whereas at the highest P concentration (125 mM), the accumulation was reduced to almost half. A significant reduction in toxic effects of Cr was determined as there was three-fold increase in total chlorophyll and biomass at the highest P amendment. Antioxidant enzymes like superoxide dismutase, catalase, peroxidase and lipid peroxidation were analyzed at various levels of Cr each amended with five levels of P. It was observed that at highest level of P amendment, the reduction percentage in toxicity was 33, 44, 39 and 44, correspondingly. Conclusively, the phosphorus amendment moderates the toxicity caused by the supplied chromium in R. sativus. This finding can be utilized to develop a novel technology for the amelioration of chromium stressed fields.
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Affiliation(s)
- D Sayantan
- Laboratory of Environment and Biotechnology, Department of Botany, Patna Science College, Patna University, Patna 800005, Bihar, India.
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Li G, Peng X, Wei L, Kang G. Salicylic acid increases the contents of glutathione and ascorbate and temporally regulates the related gene expression in salt-stressed wheat seedlings. Gene 2013; 529:321-5. [PMID: 23948081 DOI: 10.1016/j.gene.2013.07.093] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 07/22/2013] [Accepted: 07/29/2013] [Indexed: 12/26/2022]
Abstract
Exogenous salicylic acid (SA) significantly improved abiotic tolerance in higher plants, and ascorbate (ASA) and glutathione (GSH) play important roles in abiotic tolerance. In this study, SA (0.5mM) markedly increased the contents of ASA and GSH in SA-treated plants during salt stress (250mM NaCl). The transcript levels of the genes encoding ASA and GSH cycle enzymes were measured using quantitative real-time PCR. The results indicated that, during salt stress, exogenous SA significantly enhanced the transcripts of glutathione peroxidase (GPX1), phospholipid hydroperoxide glutathione peroxidase (GPX2) and dehydroascorbate reductase (DHAR) genes at 12h, glutathione reductase (GR) at 24h, 48h and 72h, glutathione-S-transferase 1 (GST1), 2 (GST2), monodehydroascorbate reductase (MDHAR) and glutathione synthetase (GS) at the 48h and 72h after salt stress, respectively. The results implied that SA temporally regulated the transcript levels of the genes encoding ASA-GSH cycle enzymes, resulting in the increased contents of GSH and ASA and enhanced salt tolerance.
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Affiliation(s)
- Gezi Li
- The National Engineering Research Centre for Wheat, The Key Laboratory of Physiology, Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou 450002, China
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