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Peng X, Wang N, Sun S, Geng L, Guo N, Liu A, Chen S, Ahammed GJ. Reactive oxygen species signaling is involved in melatonin-induced reduction of chlorothalonil residue in tomato leaves. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130212. [PMID: 36308936 DOI: 10.1016/j.jhazmat.2022.130212] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/02/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Pesticide overuse has led to serious global concerns regarding food safety and environmental pollution. Although the reduction of pesticide residue is critical, our knowledge about induced pesticide metabolism in plants remains fragmentary. Melatonin (N-acetyl-5-methoxytryptamine) is an effective stress-relieving agent in both animals and plants, but little is known about the melatonin signaling mechanism and its effect on pesticide metabolism in plants. Here, we found that exogenous melatonin treatment significantly reduced chlorothalonil residue by 41 % but suppression of endogenous melatonin accumulation increased chlorothalonil residue in tomato leaves. Moreover, melatonin increased photosynthesis, Fv/Fm, Calvin cycle enzyme activity, antioxidant enzyme activity, glutathione pool, and RESPIRATORY BURST HOMOLOG1 (RBOH1) expression in tomato leaves. However, the upregulation of RBOH1, CYP724B2, GST1, GST2, GSH and ABC, the increased glutathione concentrations and the activity of detoxification enzymes due to melatonin treatment were all significantly attenuated by the treatment with an NADPH oxidase inhibitor and a ROS scavenger, indicating a clear relationship between the reduction of pesticide residue and induction in detoxifying enzymes and genes upon melatonin treatment in an apoplastic H2O2-dependent manner. These results reveal that melatonin-induced reduction in chlorothalonil residue is mediated by H2O2 signaling in tomato leaves.
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Affiliation(s)
- Xiaohua Peng
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China
| | - Nannan Wang
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China
| | - Shuangsheng Sun
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China
| | - Lijiahong Geng
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China
| | - Ning Guo
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China
| | - Airong Liu
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China
| | - Shuangchen Chen
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China; Henan International Joint Laboratory of Stress Resistance Regulation and Safe Production of Protected Vegetables, Luoyang 471023, PR China; Henan Engineering Technology Research Center for Horticultural Crop safety and Disease Control, Luoyang 471023, PR China.
| | - Golam Jalal Ahammed
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, PR China; Henan International Joint Laboratory of Stress Resistance Regulation and Safe Production of Protected Vegetables, Luoyang 471023, PR China; Henan Engineering Technology Research Center for Horticultural Crop safety and Disease Control, Luoyang 471023, PR China.
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Liang Q, Yan J, Zhang S, Yang N, Li M, Jin Y, Bai F, Wu W, Cheng Z. CtrA activates the expression of glutathione S-transferase conferring oxidative stress resistance to Ehrlichia chaffeensis. Front Cell Infect Microbiol 2022; 12:1081614. [PMID: 36579340 PMCID: PMC9791040 DOI: 10.3389/fcimb.2022.1081614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis (HME), is a Gram-negative obligatory intracellular bacterium, which infects and multiplies in human monocytes and macrophages. Host immune cells produce reactive oxygen species (ROS) to eliminate E. chaffeensis upon infection. E. chaffeensis global transcriptional regulator CtrA activates the expression of GshA and GshB to synthesize glutathione (GSH), the most potent natural antioxidant, upon oxidative stress to combat ROS damage. However, the mechanisms exploited by E. chaffeensis to utilize GSH are still unknown. Here, we found that in E. chaffeensis CtrA activated the expression of glutathione S-transferase (GST) upon oxidative stress, and E. chaffeensis GST utilizes GSH to eliminate ROS and confers the oxidative stress resistance to E. chaffeensis. We found that CtrA bound to the promoter regions of 211 genes, including gst, in E. chaffeensis using chromatin immunoprecipitation coupled to deep sequencing (ChIP-seq). Recombinant E. chaffeensis CtrA directly bound to the gst promoter region determined with electrophoretic mobility shift assay (EMSA), and activated the gst expression determined with reporter assay. Recombinant GST showed GSH conjugation activity towards its typical substrate 2,4-dinitrochlorobenzene (CDNB) in vitro and peptide nucleic acid (PNA) transfection of E. chaffeensis, which can knock down the gst transcription level, reduced bacterial survival upon oxidative stress. Our results demonstrate that E. chaffeensis CtrA regulates GSH utilization, which plays a critical role in resistance to oxidative stress, and aid in the development of new therapeutics for HME.
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Pavlů J, Kerchev P, Černý M, Novák J, Berka M, Jobe TO, López Ramos JM, Saiz-Fernández I, Rashotte AM, Kopriva S, Brzobohatý B. Cytokinin modulates the metabolic network of sulfur and glutathione. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7417-7433. [PMID: 36226742 DOI: 10.1093/jxb/erac391] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 10/12/2022] [Indexed: 06/16/2023]
Abstract
The phytohormone cytokinin is implicated in a range of growth, developmental, and defense processes. A growing body of evidence supports a crosstalk between cytokinin and nutrient signaling pathways, such as nitrate availability. Cytokinin signaling regulates sulfur-responsive gene expression, but the underlying molecular mechanisms and their impact on sulfur-containing metabolites have not been systematically explored. Using a combination of genetic and pharmacological tools, we investigated the interplay between cytokinin signaling and sulfur homeostasis. Exogenous cytokinin triggered sulfur starvation-like gene expression accompanied by a decrease in sulfate and glutathione content. This process was uncoupled from the activity of the major transcriptional regulator of sulfate starvation signaling SULFUR LIMITATION 1 and an important glutathione-degrading enzyme, γ-glutamyl cyclotransferase 2;1, expression of which was robustly up-regulated by cytokinin. Conversely, glutathione accumulation was observed in mutants lacking the cytokinin receptor ARABIDOPSIS HISTIDINE KINASE 3 and in cytokinin-deficient plants. Cytokinin-deficient plants displayed improved root growth upon exposure to glutathione-depleting chemicals which was attributed to a higher capacity to maintain glutathione levels. These results shed new light on the interplay between cytokinin signaling and sulfur homeostasis. They position cytokinin as an important modulator of sulfur uptake, assimilation, and remobilization in plant defense against xenobiotics and root growth.
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Affiliation(s)
- Jaroslav Pavlů
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Pavel Kerchev
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
| | - Martin Černý
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
| | - Jan Novák
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
| | - Miroslav Berka
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
| | - Timothy O Jobe
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne, Germany
| | - José Maria López Ramos
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne, Germany
| | - Iñigo Saiz-Fernández
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
| | - Aaron Michael Rashotte
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Stanislav Kopriva
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne, Germany
| | - Břetislav Brzobohatý
- Department of Molecular Biology and Radiobiology, Faculty of AgriSciences, Mendel University in Brno, Brno, Czech Republic
- Central European Institute of Technology (CEITEC), Mendel University in Brno, Brno, Czech Republic
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de Bont L, Donnay N, Couturier J, Rouhier N. Redox regulation of enzymes involved in sulfate assimilation and in the synthesis of sulfur-containing amino acids and glutathione in plants. FRONTIERS IN PLANT SCIENCE 2022; 13:958490. [PMID: 36051294 PMCID: PMC9426629 DOI: 10.3389/fpls.2022.958490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Sulfur is essential in plants because of its presence in numerous molecules including the two amino acids, cysteine, and methionine. Cysteine serves also for the synthesis of glutathione and provides sulfur to many other molecules including protein cofactors or vitamins. Plants absorb sulfate from their environment and assimilate it via a reductive pathway which involves, respectively, a series of transporters and enzymes belonging to multigenic families. A tight control is needed to adjust each enzymatic step to the cellular requirements because the whole pathway consumes energy and produces toxic/reactive compounds, notably sulfite and sulfide. Glutathione is known to regulate the activity of some intermediate enzymes. In particular, it provides electrons to adenosine 5'-phosphosulfate reductases but also regulates the activity of glutamate-cysteine ligase by reducing a regulatory disulfide. Recent proteomic data suggest a more extended post-translational redox control of the sulfate assimilation pathway enzymes and of some associated reactions, including the synthesis of both sulfur-containing amino acids, cysteine and methionine, and of glutathione. We have summarized in this review the known oxidative modifications affecting cysteine residues of the enzymes involved. In particular, a prominent regulatory role of protein persulfidation seems apparent, perhaps because sulfide produced by this pathway may react with oxidized thiol groups. However, the effect of persulfidation has almost not yet been explored.
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Affiliation(s)
- Linda de Bont
- Université de Lorraine, INRAE, IAM, F-54000, Nancy, France
| | - Natacha Donnay
- Université de Lorraine, INRAE, IAM, F-54000, Nancy, France
| | - Jérémy Couturier
- Université de Lorraine, INRAE, IAM, F-54000, Nancy, France
- Institut Universitaire de France, F-75000, Paris, France
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Zhang X, Zhang L, Chen L, Lu Y, An Y. Ectopic expression γ-glutamylcysteine synthetase of Vicia sativa increased cadmium tolerance in Arabidopsis. Gene 2022; 823:146358. [PMID: 35202731 DOI: 10.1016/j.gene.2022.146358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 11/25/2022]
Abstract
Glutathione (GSH) is a multifunctional essential biothiol, and its metabolism is important for plant against toxic metals and metalloids. γ-Glutamylcysteine (γ-EC), which is catalyzed by γ-Glutamylcysteine synthetase (γ-ECS), is a rate-limiting intermediate in GSH synthesis. Here, a γ-ECS gene (Vsγ-ECS) from Vicia sativa was cloned, and its function in modulating Cd tolerance was studied. Vsγ-ECS is a chloroplast localization protein, and the expression of Vsγ-ECS was upregulated by Cd stress in root of V. sativa. Heterologous expression of Vsγ-ECS (35S::Vsγ-ECS) in Arabidopsis enhanced the Cd tolerance of plants through improved primary root length, fresh weight, chlorophyll content and low degree of oxidation associated with reduced H2O2 and lipid peroxidation. However, the Cd accumulation of Arabidopsis had no effect on Vsγ-ECS overexpression. Further analysis showed that the increased Cd tolerance in 35S::Vsγ-ECS was mainly due to the capacity of increasing GSH synthesis that improved Cd chelation by GSH and phytochelatins (PCs) and alleviated the oxidative stress caused by Cd stress. In summary, a γ-ECS was characterized from V. sativa, and it demonstrated a property for increasing GSH and PC synthesis to protect plants from Cd poisoning.
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Affiliation(s)
- Xingxing Zhang
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Guangzhou 510316, Guangdong, China
| | - Lu Zhang
- Zhejiang Provincial Key Laboratory of Bioremediation of Soil Contamination, Zhejiang Agriculture and Forestry University, Hangzhou 311300, Zhejiang, China
| | - Lijuan Chen
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Guangzhou 510316, Guangdong, China
| | - Yinglin Lu
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Guangzhou 510316, Guangdong, China
| | - Yuxing An
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Guangzhou 510316, Guangdong, China.
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Luo W, Long Y, Feng Z, Li R, Huang X, Zhong J, Liu D, Zhao H. A γ-glutamylcysteine ligase AcGCL alleviates cadmium-inhibited fructooligosaccharides metabolism by modulating glutathione level in Allium cepa L. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126255. [PMID: 34157465 DOI: 10.1016/j.jhazmat.2021.126255] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 05/12/2021] [Accepted: 05/26/2021] [Indexed: 06/13/2023]
Abstract
Fructooligosaccharides (FOS) are important carbohydrates in plants. Cadmium (Cd) toxicity limits growth and development in several plant species. Whether FOS metabolism is affected by Cd and the molecular mechanisms of tolerance of the effects of Cd toxicity in plants remain enigmatic. In the present study, FOS metabolism was analyzed under Cd stress in onion (Allium cepa L.). Results showed that Cd stress can inhibit FOS accumulation in onion, followed by the upregulation of a putative onion γ-glutamylcysteine ligase gene AcGCL. Heterologous expression of the AcGCL protein in Escherichia coli revealed that this recombinant enzyme has GCL activity. Furthermore, overexpressing AcGCL significantly increased glutathione (GSH) accumulation in young onion roots under Cd treatment, accompanied by increased phytochelatin (PC) amount, and increased transcript expression of GSH synthetase (GS), and phytochelatin synthase (PCS) genes. Notably, compared with control, overexpressing AcGCL ameliorated Cd phytotoxicity on onion FOS metabolism, which correlated with increased FOS synthesis. Taken together, these results suggest that the function of AcGCL as a γ-glutamylcysteine ligase can alleviate Cd inhibited FOS metabolism by modulating GSH levels in onion.
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Affiliation(s)
- Wei Luo
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou 510642, China; Guangdong Vegetable Engineering and Technology Research Center, South China Agricultural University, Guangzhou 510642, China
| | - Yuming Long
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Zili Feng
- School of Bioscience and Engineering, Shaanxi University of Technology, Hanzhong 723001, China
| | - Rui Li
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Xiaojia Huang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China
| | - Jiaxin Zhong
- Centre for Organismal Studies Heidelberg, Department of Plant Molecular Physiology, Heidelberg University, Heidelberg 69120, Germany
| | - Dongyun Liu
- The Technology Center for Protein Sciences, Tsinghua University, Beijing 100084, China
| | - Hongbo Zhao
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China), Ministry of Agriculture and Rural Affairs, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou 510642, China; Guangdong Vegetable Engineering and Technology Research Center, South China Agricultural University, Guangzhou 510642, China.
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Dorion S, Ouellet JC, Rivoal J. Glutathione Metabolism in Plants under Stress: Beyond Reactive Oxygen Species Detoxification. Metabolites 2021; 11:metabo11090641. [PMID: 34564457 PMCID: PMC8464934 DOI: 10.3390/metabo11090641] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 01/16/2023] Open
Abstract
Glutathione is an essential metabolite for plant life best known for its role in the control of reactive oxygen species (ROS). Glutathione is also involved in the detoxification of methylglyoxal (MG) which, much like ROS, is produced at low levels by aerobic metabolism under normal conditions. While several physiological processes depend on ROS and MG, a variety of stresses can dramatically increase their concentration leading to potentially deleterious effects. In this review, we examine the structure and the stress regulation of the pathways involved in glutathione synthesis and degradation. We provide a synthesis of the current knowledge on the glutathione-dependent glyoxalase pathway responsible for MG detoxification. We present recent developments on the organization of the glyoxalase pathway in which alternative splicing generate a number of isoforms targeted to various subcellular compartments. Stress regulation of enzymes involved in MG detoxification occurs at multiple levels. A growing number of studies show that oxidative stress promotes the covalent modification of proteins by glutathione. This post-translational modification is called S-glutathionylation. It affects the function of several target proteins and is relevant to stress adaptation. We address this regulatory function in an analysis of the enzymes and pathways targeted by S-glutathionylation.
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Yu J, Li Y, Qin Z, Guo S, Li Y, Miao Y, Song C, Chen S, Dai S. Plant Chloroplast Stress Response: Insights from Thiol Redox Proteomics. Antioxid Redox Signal 2020; 33:35-57. [PMID: 31989831 DOI: 10.1089/ars.2019.7823] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Significance: Plant chloroplasts generate reactive oxygen species (ROS) during photosynthesis, especially under stresses. The sulfhydryl groups of protein cysteine residues are susceptible to redox modifications, which regulate protein structure and function, and thus different signaling and metabolic processes. The ROS-governed protein thiol redox switches play important roles in chloroplasts. Recent Advances: Various high-throughput thiol redox proteomic approaches have been developed, and they have enabled the improved understanding of redox regulatory mechanisms in chloroplasts. For example, the thioredoxin-modulated antioxidant enzymes help to maintain cellular ROS homeostasis. The light- and dark-dependent redox regulation of photosynthetic electron transport, the Calvin/Benson cycle, and starch biosynthesis ensures metabolic coordination and efficient energy utilization. In addition, redox cascades link the light with the dynamic changes of metabolites in nitrate and sulfur assimilation, shikimate pathway, and biosynthesis of fatty acid hormone as well as purine, pyrimidine, and thiamine. Importantly, redox regulation of tetrapyrrole and chlorophyll biosynthesis is critical to balance the photodynamic tetrapyrrole intermediates and prevent oxidative damage. Moreover, redox regulation of diverse elongation factors, chaperones, and kinases plays an important role in the modulation of gene expression, protein conformation, and posttranslational modification that contribute to photosystem II (PSII) repair, state transition, and signaling in chloroplasts. Critical Issues: This review focuses on recent advances in plant thiol redox proteomics and redox protein networks toward understanding plant chloroplast signaling, metabolism, and stress responses. Future Directions: Using redox proteomics integrated with biochemical and molecular genetic approaches, detailed studies of cysteine residues, their redox states, cross talk with other modifications, and the functional implications will yield a holistic understanding of chloroplast stress responses.
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Affiliation(s)
- Juanjuan Yu
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China.,Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China.,College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Ying Li
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Zhi Qin
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Siyi Guo
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, Kaifeng, China
| | - Yongfang Li
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Yuchen Miao
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, Kaifeng, China
| | - Chunpeng Song
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, Kaifeng, China
| | - Sixue Chen
- Department of Biology, Genetics Institute, Plant Molecular and Cellular Biology Program, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, USA
| | - Shaojun Dai
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China.,Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
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García-Quirós E, Alché JDD, Karpinska B, Foyer CH. Glutathione redox state plays a key role in flower development and pollen vigour. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:730-741. [PMID: 31557297 PMCID: PMC6946011 DOI: 10.1093/jxb/erz376] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 08/10/2019] [Indexed: 05/04/2023]
Abstract
The importance of the glutathione pool in the development of reproductive tissues and in pollen tube growth was investigated in wild-type (WT) Arabidopsis thaliana, a reporter line expressing redox-sensitive green fluorescent protein (roGFP2), and a glutathione-deficient cad2-1 mutant (cad2-1/roGFP2). The cad2-1/roGFP2 flowers had significantly less reduced glutathione (GSH) and more glutathione disulfide (GSSG) than WT or roGFP2 flowers. The stigma, style, anther, germinated pollen grains, and pollen tubes of roGFP2 flowers had a low degree of oxidation. However, these tissues were more oxidized in cad2-1/roGFP2 flowers than the roGFP2 controls. The ungerminated pollen grains were significantly more oxidized than the germinated pollen grains, indicating that the pollen cells become reduced upon the transition from the quiescent to the metabolically active state during germination. The germination percentage was lower in cad2-1/roGFP2 pollen and pollen tube growth arrested earlier than in roGFP2 pollen, demonstrating that increased cellular reduction is essential for pollen tube growth. These findings establish that ungerminated pollen grains exist in a relatively oxidized state compared with germinating pollen grains. Moreover, failure to accumulate glutathione and maintain a high GSH/GSSG ratio has a strong negative effect on pollen germination.
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Affiliation(s)
- Estefanía García-Quirós
- Plant Reproductive Biology and Advanced Microscopy Laboratory, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, Granada, Spain
- Centre for Plant Sciences, School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Juan de Dios Alché
- Plant Reproductive Biology and Advanced Microscopy Laboratory, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | - Barbara Karpinska
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Christine H Foyer
- Plant Reproductive Biology and Advanced Microscopy Laboratory, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, Granada, Spain
- Centre for Plant Sciences, School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Correspondence:
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Hou J, Sun Q, Li J, Ahammed GJ, Yu J, Fang H, Xia X. Glutaredoxin S25 and its interacting TGACG motif-binding factor TGA2 mediate brassinosteroid-induced chlorothalonil metabolism in tomato plants. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113256. [PMID: 31563783 DOI: 10.1016/j.envpol.2019.113256] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 07/31/2019] [Accepted: 09/13/2019] [Indexed: 06/10/2023]
Abstract
The presence of pesticide residues in fresh fruits and vegetables poses a serious threat to human health. Brassinosteroids (BRs) can reduce pesticide residues in plants, but the underlying mechanisms still remain unclear. Here, we identified a tomato glutaredoxin gene GRXS25 which was induced by 24-epibrassinolide (EBR) and chlorothalonil (CHT) in a way dependent on apoplastic reactive oxygen species (ROS). Silencing of GRXS25 in tomato abolished EBR-induced glutathione S-transferases (GSTs) gene expression and activity, leading to an increased CHT residue. Yeast two-hybrid and bimolecular fluorescence complementation assays showed protein-protein interaction between GRXS25 and a transcription factor TGA2. Electrophoretic mobility shift and chromatin immunoprecipitation assays indicated that TGA2 factor bound to the TGACG-motif in the GST3 promoter. While silencing of TGA2 strongly compromised, overexpression of TGA2 enhanced expression of GST genes and CHT residue metabolism. Our results suggest that BR-induced apoplastic ROS trigger metabolism of pesticide residue in tomato plants through activating TGA2 factor via GRXS25-dependent posttranslational redox modification. Activation of plant detoxification through physiological approaches has potential implication in improving the food safety of agricultural products.
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Affiliation(s)
- Jiayin Hou
- Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, PR China
| | - Qian Sun
- Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, PR China
| | - Junjie Li
- Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, PR China
| | - Golam Jalal Ahammed
- College of Forestry, Henan University of Science and Technology, 263 Kaiyuan Avenue, Luoyang, PR China
| | - Jingquan Yu
- Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, PR China; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, 866 Yuhangtang Road, Hangzhou, 310058, PR China
| | - Hua Fang
- Institute of Pesticide & Environmental Toxicology, Zijingang Campus, Zhejiang University, Hangzhou, 310058, China
| | - Xiaojian Xia
- Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, PR China.
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Sasoni N, Ferrero DML, Guerrero SA, Iglesias AA, Arias DG. First evidence of glutathione metabolism in Leptospira interrogans. Free Radic Biol Med 2019; 143:366-374. [PMID: 31465831 DOI: 10.1016/j.freeradbiomed.2019.08.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/08/2019] [Accepted: 08/24/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND Glutathione (GSH) plays a role as a main antioxidant metabolite in all eukaryotes and many prokaryotes. Most of the organisms synthesize GSH by a pathway involving two enzymatic reactions, each one consuming one molecule of ATP. In a first step mediated by glutamate-cysteine ligase (GCL), the carboxylate of l-glutamic acid reacts with l-cysteine to form the dipeptide γ-glutamylcysteine (γ-GC). The second step involves the addition of glycine to the C-terminal of γ-GC catalyzed by glutathione synthetase (GS). In many bacteria, such as in the pathogen Leptospira interrogans, the main intracellular thiol has not yet been identified and the presence of GSH is not clear. METHODS We performed the molecular cloning of the genes gshA and gshB from L. interrogans; which respectively code for GCL and GS. After heterologous expression of the cloned genes we recombinantly produced the respective proteins with high degree of purity. These enzymes were exhaustively characterized in their biochemical properties. In addition, we determined the contents of GSH and the activity of related enzymes (and proteins) in cell extracts of the bacterium. RESULTS We functionally characterized GCL and GS, the two enzymes putatively involved in GSH synthesis in L. interrogans serovar Copenhageni. LinGCL showed higher substrate promiscuity (was active in presence of l-glutamic acid, l-cysteine and ATP, and also with GTP, l-aspartic acid and l-serine in lower proportion) unlike LinGS (which was only active with γ-GC, l-glycine and ATP). LinGCL is significantly inhibited by γ-GC and GSH, the respective intermediate and final product of the synthetic pathway. GSH showed inhibitory effect over LinGS but with a lower potency than LinGCL. Going further, we detected the presence of GSH in L. interrogans cells grown under basal conditions and also determined enzymatic activity of several GSH-dependent/related proteins in cell extracts. CONCLUSIONS and General Significance. Our results contribute with novel insights concerning redox metabolism in L. interrogans, mainly supporting that GSH is part of the antioxidant defense in the bacterium.
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Affiliation(s)
- Natalia Sasoni
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Facultad de Bioquímica y Ciencias Biológicas (FBCB), Centro Científico Tecnológico CONICET Santa Fe, Colectora Ruta Nacional Nº 168 km 0, Santa Fe, 3000, Argentina
| | - Danisa M L Ferrero
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Facultad de Bioquímica y Ciencias Biológicas (FBCB), Centro Científico Tecnológico CONICET Santa Fe, Colectora Ruta Nacional Nº 168 km 0, Santa Fe, 3000, Argentina
| | - Sergio A Guerrero
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Facultad de Bioquímica y Ciencias Biológicas (FBCB), Centro Científico Tecnológico CONICET Santa Fe, Colectora Ruta Nacional Nº 168 km 0, Santa Fe, 3000, Argentina
| | - Alberto A Iglesias
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Facultad de Bioquímica y Ciencias Biológicas (FBCB), Centro Científico Tecnológico CONICET Santa Fe, Colectora Ruta Nacional Nº 168 km 0, Santa Fe, 3000, Argentina
| | - Diego G Arias
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Facultad de Bioquímica y Ciencias Biológicas (FBCB), Centro Científico Tecnológico CONICET Santa Fe, Colectora Ruta Nacional Nº 168 km 0, Santa Fe, 3000, Argentina.
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12
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Telman W, Dietz KJ. Thiol redox-regulation for efficient adjustment of sulfur metabolism in acclimation to abiotic stress. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4223-4236. [PMID: 30868161 DOI: 10.1093/jxb/erz118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 03/07/2019] [Indexed: 06/09/2023]
Abstract
Sulfur assimilation and sulfur metabolism are tightly controlled at the transcriptional, post-transcriptional, and post-translational levels in order to meet the demand for reduced sulfur in growth and metabolism. These regulatory mechanisms coordinate the cellular sulfhydryl supply with carbon and nitrogen assimilation in particular. Redox homeostasis is an important cellular parameter intimately connected to sulfur by means of multiple thiol modifications. Post-translational thiol modifications such as disulfide formation, sulfenylation, S-nitrosylation, persulfidation, and S-glutathionylation allow for versatile switching and adjustment of protein functions. This review focuses on redox-regulation of enzymes involved in the sulfur assimilation pathway, namely adenosine 5´-phosphosulfate reductase (APR), adenosine 5´-phosphosulfate kinase (APSK), and γ-glutamylcysteine ligase (GCL). The activity of these enzymes is adjusted at the transcriptional and post-translational level depending on physiological requirements and the state of the redox and reactive oxygen species network, which are tightly linked to abiotic stress conditions. Hormone-dependent fine-tuning contributes to regulation of sulfur assimilation. Thus, the link between oxylipin signalling and sulfur assimilation has been substantiated by identification of the so-called COPS module in the chloroplast with its components cyclophilin 20-3, O-acetylserine thiol lyase, 2-cysteine peroxiredoxin, and serine acetyl transferase. We now have a detailed understanding of how regulation enables the fine-tuning of sulfur assimilation under both normal and abiotic stress conditions.
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Affiliation(s)
- Wilena Telman
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Universitätsstr. 25, Bielefeld, Germany
| | - Karl-Josef Dietz
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Universitätsstr. 25, Bielefeld, Germany
- Center for Biotechnology-CeBiTec, Bielefeld University, Universitätsstr. 27, Bielefeld, Germany
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13
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Jez JM. Structural biology of plant sulfur metabolism: from sulfate to glutathione. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4089-4103. [PMID: 30825314 DOI: 10.1093/jxb/erz094] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 02/12/2019] [Indexed: 06/09/2023]
Abstract
Sulfur is an essential element for all organisms. Plants must assimilate this nutrient from the environment and convert it into metabolically useful forms for the biosynthesis of a wide range of compounds, including cysteine and glutathione. This review summarizes structural biology studies on the enzymes involved in plant sulfur assimilation [ATP sulfurylase, adenosine-5'-phosphate (APS) reductase, and sulfite reductase], cysteine biosynthesis (serine acetyltransferase and O-acetylserine sulfhydrylase), and glutathione biosynthesis (glutamate-cysteine ligase and glutathione synthetase) pathways. Overall, X-ray crystal structures of enzymes in these core pathways provide molecular-level information on the chemical events that allow plants to incorporate sulfur into essential metabolites and revealed new biochemical regulatory mechanisms, such as structural rearrangements, protein-protein interactions, and thiol-based redox switches, for controlling different steps in these pathways.
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Affiliation(s)
- Joseph M Jez
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
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14
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Abstract
Sulfur is present in the amino acids cysteine and methionine and in a large range of essential coenzymes and cofactors and is therefore essential for all organisms. It is also a constituent of sulfate esters in proteins, carbohydrates, and numerous cellular metabolites. The sulfation and desulfation reactions modifying a variety of different substrates are commonly known as sulfation pathways. Although relatively little is known about the function of most sulfated metabolites, the synthesis of activated sulfate used in sulfation pathways is essential in both animal and plant kingdoms. In humans, mutations in the genes encoding the sulfation pathway enzymes underlie a number of developmental aberrations, and in flies and worms, their loss-of-function is fatal. In plants, a lower capacity for synthesizing activated sulfate for sulfation reactions results in dwarfism, and a complete loss of activated sulfate synthesis is also lethal. Here, we review the similarities and differences in sulfation pathways and associated processes in animals and plants, and we point out how they diverge from bacteria and yeast. We highlight the open questions concerning localization, regulation, and importance of sulfation pathways in both kingdoms and the ways in which findings from these "red" and "green" experimental systems may help reciprocally address questions specific to each of the systems.
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Affiliation(s)
- Süleyman Günal
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne 50674, Germany
| | - Rebecca Hardman
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Stanislav Kopriva
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne 50674, Germany.
| | - Jonathan Wolf Mueller
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom; Centre for Endocrinology, Diabetes and Metabolism (CEDAM), Birmingham Health Partners, Birmingham B15 2TH, United Kingdom.
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15
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Plant glutathione biosynthesis revisited: redox-mediated activation of glutamylcysteine ligase does not require homo-dimerization. Biochem J 2019; 476:1191-1203. [PMID: 30877193 PMCID: PMC6463388 DOI: 10.1042/bcj20190072] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 02/08/2019] [Accepted: 03/04/2019] [Indexed: 11/17/2022]
Abstract
Plant γ-glutamylcysteine ligase (GCL), catalyzing the first and tightly regulated step of glutathione (GSH) biosynthesis, is redox-activated via formation of an intramolecular disulfide bond. In vitro, redox-activation of recombinant GCL protein causes formation of homo-dimers. Here, we have investigated whether dimerization occurs in vivo and if so whether it contributes to redox-activation. FPLC analysis indicated that recombinant redox-activated WT (wild type) AtGCL dissociates into monomers at concentrations below 10-6 M, i.e. below the endogenous AtGCL concentration in plastids, which was estimated to be in the micromolar range. Thus, dimerization of redox-activated GCL is expected to occur in vivo To determine the possible impact of dimerization on redox-activation, AtGCL mutants were generated in which salt bridges or hydrophobic interactions at the dimer interface were interrupted. WT AtGCL and mutant proteins were analyzed by non-reducing SDS-PAGE to address their redox state and probed by FPLC for dimerization status. Furthermore, their substrate kinetics (K M, V max) were compared. The results indicate that dimer formation is not required for redox-mediated enzyme activation. Also, crystal structure analysis confirmed that dimer formation does not affect binding of GSH as competitive inhibitor. Whether dimerization affects other enzyme properties, e.g. GCL stability in vivo, remains to be investigated.
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Roach T, Stöggl W, Baur T, Kranner I. Distress and eustress of reactive electrophiles and relevance to light stress acclimation via stimulation of thiol/disulphide-based redox defences. Free Radic Biol Med 2018; 122:65-73. [PMID: 29563047 DOI: 10.1016/j.freeradbiomed.2018.03.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 03/10/2018] [Accepted: 03/16/2018] [Indexed: 01/30/2023]
Abstract
Photosynthetic organisms suffering from light stress have to cope with an increased formation of reactive short-chain aldehydes. Singlet oxygen generated from highly-charged reaction centres can peroxidise the poly-unsaturated fatty acid (PUFA)-rich thylakoid membranes they are embedded in. Lipid peroxides decay to release α,β-unsaturated aldehydes that are reactive electrophile species (RES). Acrolein is one of the most abundant and reactive RES produced in chloroplasts. Here, in the model chlorophyte alga Chlamydomonas reinhardtii, a clear concentration-dependent "distress" induced by acrolein intoxication was observed in conjunction with depletion of the glutathione pool. The glutathione redox state (EGSSG/2GSH) strongly correlated (R2 = 0.95) with decreasing Fv/Fm values of chlorophyll fluorescence. However, treatment of C. reinhardtii with sub-toxic acrolein concentrations increased glutathione concentrations and raised the protein levels of a glutathione-S-transferase (GSTS1), mimicking the response to excess light, indicating that at lower concentrations, acrolein may contribute to high light acclimation, which could be interpreted as "eustress". Furthermore, similar patterns of chloroplastic protein carbonylation occurred under light stress and in response to exogenous acrolein. Priming cells by low doses of acrolein increased the alga's resistance to singlet oxygen. A RNA seq. analysis showed a large overlap in gene regulation under singlet oxygen and acrolein stresses. Particularly enriched were transcripts of enzymes involved in thiol/disulphide exchanges. Some of the genes are regulated by the SOR1 transcription factor, but acrolein treatment still induced an increase in glutathione contents and enhanced singlet oxygen tolerance of the sor1 mutant. The results support a role for RES in chloroplast-to-nucleus retrograde signalling during high light acclimation, with involvement of SOR1 and other pathways.
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Affiliation(s)
- Thomas Roach
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria.
| | - Wolfgang Stöggl
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Theresa Baur
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Ilse Kranner
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
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Ahmad N, Malagoli M, Wirtz M, Hell R. Drought stress in maize causes differential acclimation responses of glutathione and sulfur metabolism in leaves and roots. BMC PLANT BIOLOGY 2016; 16:247. [PMID: 27829370 PMCID: PMC5103438 DOI: 10.1186/s12870-016-0940-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 10/31/2016] [Indexed: 05/08/2023]
Abstract
BACKGROUND Drought is the most important environmental stress that limits crop yield in a global warming world. Despite the compelling evidence of an important role of oxidized and reduced sulfur-containing compounds during the response of plants to drought stress (e.g. sulfate for stomata closure or glutathione for scavenging of reactive oxygen species), the assimilatory sulfate reduction pathway is almost not investigated at the molecular or at the whole plant level during drought. RESULTS In the present study, we elucidated the role of assimilatory sulfate reduction in roots and leaves of the staple crop maize after application of drought stress. The time-resolved dynamics of the adaption processes to the stress was analyzed in a physiological relevant situation -when prolonged drought caused significant oxidation stress but root growth should be maintained. The allocation of sulfate was significantly shifted to the roots upon drought and allowed for significant increase of thiols derived from sulfate assimilation in roots. This enabled roots to produce biomass, while leaf growth was stopped. Accumulation of harmful reactive oxygen species caused oxidation of the glutathione pool and decreased glutathione levels in leaves. Surprisingly, flux analysis using [35S]-sulfate demonstrated a significant down-regulation of sulfate assimilation and cysteine synthesis in leaves due to the substantial decrease of serine acetyltransferase activity. The insufficient cysteine supply caused depletion of glutathione pool in spite of significant transcriptional induction of glutathione synthesis limiting GSH1. Furthermore, drought impinges on transcription of membrane-localized sulfate transport systems in leaves and roots, which provides a potential molecular mechanism for the reallocation of sulfur upon prolonged water withdrawal. CONCLUSIONS The study demonstrated a significant and organ-specific impact of drought upon sulfate assimilation. The sulfur metabolism related alterations at the transcriptional, metabolic and enzyme activity level are consistent with a promotion of root growth to search for water at the expense of leaf growth. The results provide evidence for the importance of antagonistic regulation of sulfur metabolism in leaves and roots to enable successful drought stress response at the whole plant level.
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Affiliation(s)
- Nisar Ahmad
- Centre for Organismal Studies Heidelberg, Heidelberg University, Im Neuenheimer Feld 360, 69120, Heidelberg, Germany
- University of Science & Technology Bannu, Bannu, Pakistan
| | - Mario Malagoli
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
| | - Markus Wirtz
- Centre for Organismal Studies Heidelberg, Heidelberg University, Im Neuenheimer Feld 360, 69120, Heidelberg, Germany
| | - Ruediger Hell
- Centre for Organismal Studies Heidelberg, Heidelberg University, Im Neuenheimer Feld 360, 69120, Heidelberg, Germany.
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18
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Jez JM, Ravilious GE, Herrmann J. Structural biology and regulation of the plant sulfation pathway. Chem Biol Interact 2016; 259:31-38. [DOI: 10.1016/j.cbi.2016.02.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 02/16/2016] [Accepted: 02/22/2016] [Indexed: 11/26/2022]
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19
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Noctor G, Mhamdi A, Foyer CH. Oxidative stress and antioxidative systems: recipes for successful data collection and interpretation. PLANT, CELL & ENVIRONMENT 2016; 39:1140-60. [PMID: 26864619 DOI: 10.1111/pce.12726] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/25/2016] [Accepted: 01/31/2016] [Indexed: 05/18/2023]
Abstract
Oxidative stress and reactive oxygen species (ROS) are common to many fundamental responses of plants. Enormous and ever-growing interest has focused on this research area, leading to an extensive literature that documents the tremendous progress made in recent years. As in other areas of plant biology, advances have been greatly facilitated by developments in genomics-dependent technologies and the application of interdisciplinary techniques that generate information at multiple levels. At the same time, advances in understanding ROS are fundamentally reliant on the use of biochemical and cell biology techniques that are specific to the study of oxidative stress. It is therefore timely to revisit these approaches with the aim of providing a guide to convenient methods and assisting interested researchers in avoiding potential pitfalls. Our critical overview of currently popular methodologies includes a detailed discussion of approaches used to generate oxidative stress, measurements of ROS themselves, determination of major antioxidant metabolites, assays of antioxidative enzymes and marker transcripts for oxidative stress. We consider the applicability of metabolomics, proteomics and transcriptomics approaches and discuss markers such as damage to DNA and RNA. Our discussion of current methodologies is firmly anchored to future technological developments within this popular research field.
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Affiliation(s)
- Graham Noctor
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Bâtiment 630, 91405, Orsay, France
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, Bâtiment 630, 91405, Orsay, France
| | - Amna Mhamdi
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Bâtiment 630, 91405, Orsay, France
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, Bâtiment 630, 91405, Orsay, France
- Department of Plant Biotechnology and Bioinformatics, Ghent University, VIB, Department of Plant Systems Biology, Technologie Park 927, B-9052, Ghent, Belgium
| | - Christine H Foyer
- Centre for Plant Sciences, School of Biology and Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
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20
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Dietz KJ, Hell R. Thiol switches in redox regulation of chloroplasts: balancing redox state, metabolism and oxidative stress. Biol Chem 2016; 396:483-94. [PMID: 25741945 DOI: 10.1515/hsz-2014-0281] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 03/02/2015] [Indexed: 12/24/2022]
Abstract
In photosynthesizing chloroplasts, rapidly changing energy input, intermediate generation of strong reductants as well as oxidants and multiple participating physicochemical processes and pathways, call for efficient regulation. Coupling redox information to protein function via thiol modifications offers a powerful mechanism to activate, down-regulate and coordinate interdependent processes. Efficient thiol switching of target proteins involves the thiol-disulfide redox regulatory network, which is highly elaborated in chloroplasts. This review addresses the features of this network. Its conditional function depends on specificity of reduction and oxidation reactions and pathways, thiol redox buffering, but also formation of heterogeneous milieus by microdomains, metabolite gradients and macromolecular assemblies. One major player is glutathione. Its synthesis and function is under feedback redox control. The number of thiol-controlled processes and involved thiol switched proteins is steadily increasing, e.g., in tetrapyrrole biosynthesis, plastid transcription and plastid translation. Thus chloroplasts utilize an intricate and versatile redox regulatory network for intraorganellar and retrograde communication.
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21
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Kovacs I, Durner J, Lindermayr C. Crosstalk between nitric oxide and glutathione is required for NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1)-dependent defense signaling in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2015; 208:860-72. [PMID: 26096525 DOI: 10.1111/nph.13502] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 05/04/2015] [Indexed: 05/18/2023]
Abstract
Nitric oxide (NO) is a ubiquitous signaling molecule involved in a wide range of physiological and pathophysiological processes in animals and plants. Although its significant influence on plant immunity is well known, information about the exact regulatory mechanisms and signaling pathways involved in the defense response to pathogens is still limited. We used genetic, biochemical, pharmacological approaches in combination with infection experiments to investigate the NO-triggered salicylic acid (SA)-dependent defense response in Arabidopsis thaliana. The NO donor S-nitrosoglutathione (GSNO) promoted the nuclear accumulation of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1) protein accompanied by an elevated SA concentration and the activation of pathogenesis-related (PR) genes, leading to induced resistance of A. thaliana against Pseudomonas infection. Moreover, NO induced a rapid change in the glutathione status, resulting in increased concentrations of glutathione, which is required for SA accumulation and activation of the NPR1-dependent defense response. Our data imply crosstalk between NO and glutathione, which is integral to the NPR1-dependent defense signaling pathway, and further demonstrate that glutathione is not only an important cellular redox buffer but also a signaling molecule in the plant defense response.
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Affiliation(s)
- Izabella Kovacs
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München - German Research Center for Environmental Health, D-85764, Munich/Neuherberg, Germany
| | - Jörg Durner
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München - German Research Center for Environmental Health, D-85764, Munich/Neuherberg, Germany
- Chair of Biochemical Plant Pathology, Technische Universität München, 85354, Freising, Germany
| | - Christian Lindermayr
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München - German Research Center for Environmental Health, D-85764, Munich/Neuherberg, Germany
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Herrmann J, Nathin D, Lee SG, Sun T, Jez JM. Recapitulating the Structural Evolution of Redox Regulation in Adenosine 5'-Phosphosulfate Kinase from Cyanobacteria to Plants. J Biol Chem 2015; 290:24705-14. [PMID: 26294763 DOI: 10.1074/jbc.m115.679514] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Indexed: 11/06/2022] Open
Abstract
In plants, adenosine 5'-phosphosulfate (APS) kinase (APSK) is required for reproductive viability and the production of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as a sulfur donor in specialized metabolism. Previous studies of the APSK from Arabidopsis thaliana (AtAPSK) identified a regulatory disulfide bond formed between the N-terminal domain (NTD) and a cysteine on the core scaffold. This thiol switch is unique to mosses, gymnosperms, and angiosperms. To understand the structural evolution of redox control of APSK, we investigated the redox-insensitive APSK from the cyanobacterium Synechocystis sp. PCC 6803 (SynAPSK). Crystallographic analysis of SynAPSK in complex with either APS and a non-hydrolyzable ATP analog or APS and sulfate revealed the overall structure of the enzyme, which lacks the NTD found in homologs from mosses and plants. A series of engineered SynAPSK variants reconstructed the structural evolution of the plant APSK. Biochemical analyses of SynAPSK, SynAPSK H23C mutant, SynAPSK fused to the AtAPSK NTD, and the fusion protein with the H23C mutation showed that the addition of the NTD and cysteines recapitulated thiol-based regulation. These results reveal the molecular basis for structural changes leading to the evolution of redox control of APSK in the green lineage from cyanobacteria to plants.
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Affiliation(s)
- Jonathan Herrmann
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - David Nathin
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Soon Goo Lee
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Tony Sun
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Joseph M Jez
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
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23
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Cahoon RE, Lutke WK, Cameron JC, Chen S, Lee SG, Rivard RS, Rea PA, Jez JM. Adaptive Engineering of Phytochelatin-based Heavy Metal Tolerance. J Biol Chem 2015; 290:17321-30. [PMID: 26018077 DOI: 10.1074/jbc.m115.652123] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Indexed: 11/06/2022] Open
Abstract
Metabolic engineering approaches are increasingly employed for environmental applications. Because phytochelatins (PC) protect plants from heavy metal toxicity, strategies directed at manipulating the biosynthesis of these peptides hold promise for the remediation of soils and groundwaters contaminated with heavy metals. Directed evolution of Arabidopsis thaliana phytochelatin synthase (AtPCS1) yields mutants that confer levels of cadmium tolerance and accumulation greater than expression of the wild-type enzyme in Saccharomyces cerevisiae, Arabidopsis, or Brassica juncea. Surprisingly, the AtPCS1 mutants that enhance cadmium tolerance and accumulation are catalytically less efficient than wild-type enzyme. Metabolite analyses indicate that transformation with AtPCS1, but not with the mutant variants, decreases the levels of the PC precursors, glutathione and γ-glutamylcysteine, upon exposure to cadmium. Selection of AtPCS1 variants with diminished catalytic activity alleviates depletion of these metabolites, which maintains redox homeostasis while supporting PC synthesis during cadmium exposure. These results emphasize the importance of metabolic context for pathway engineering and broaden the range of tools available for environmental remediation.
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Affiliation(s)
- Rebecca E Cahoon
- From the Department of Biology, Washington University, St. Louis, Missouri 63130, the Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - W Kevin Lutke
- the Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Jeffrey C Cameron
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Sixue Chen
- the Donald Danforth Plant Science Center, St. Louis, Missouri 63132, the Department of Biology, Genetics Institute, University of Florida, Gainesville, Florida 32610, and
| | - Soon Goo Lee
- From the Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Rebecca S Rivard
- the Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Philip A Rea
- the Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Joseph M Jez
- From the Department of Biology, Washington University, St. Louis, Missouri 63130, the Donald Danforth Plant Science Center, St. Louis, Missouri 63132, the Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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24
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Hernández LE, Sobrino-Plata J, Montero-Palmero MB, Carrasco-Gil S, Flores-Cáceres ML, Ortega-Villasante C, Escobar C. Contribution of glutathione to the control of cellular redox homeostasis under toxic metal and metalloid stress. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2901-11. [PMID: 25750419 DOI: 10.1093/jxb/erv063] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The accumulation of toxic metals and metalloids, such as cadmium (Cd), mercury (Hg), or arsenic (As), as a consequence of various anthropogenic activities, poses a serious threat to the environment and human health. The ability of plants to take up mineral nutrients from the soil can be exploited to develop phytoremediation technologies able to alleviate the negative impact of toxic elements in terrestrial ecosystems. However, we must select plant species or populations capable of tolerating exposure to hazardous elements. The tolerance of plant cells to toxic elements is highly dependent on glutathione (GSH) metabolism. GSH is a biothiol tripeptide that plays a fundamental dual role: first, as an antioxidant to mitigate the redox imbalance caused by toxic metal(loid) accumulation, and second as a precursor of phytochelatins (PCs), ligand peptides that limit the free ion cellular concentration of those pollutants. The sulphur assimilation pathway, synthesis of GSH, and production of PCs are tightly regulated in order to alleviate the phytotoxicity of different hazardous elements, which might induce specific stress signatures. This review provides an update on mechanisms of tolerance that depend on biothiols in plant cells exposed to toxic elements, with a particular emphasis on the Hg-triggered responses, and considering the contribution of hormones to their regulation.
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Affiliation(s)
- Luis E Hernández
- Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain
| | - Juan Sobrino-Plata
- Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain Department of Environmental Sciences, Universidad de Castilla-La Mancha, Campus Fábrica de Armas, ES-45070 Toledo, Spain
| | - M Belén Montero-Palmero
- Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain Department of Environmental Sciences, Universidad de Castilla-La Mancha, Campus Fábrica de Armas, ES-45070 Toledo, Spain
| | - Sandra Carrasco-Gil
- Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain † Present address: Aula Dei Experimental Research Station-CSIC, Avd. Montañana, ES- 50059 Zaragoza, Spain
| | - M Laura Flores-Cáceres
- Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain
| | - Cristina Ortega-Villasante
- Laboratory of Plant Physiology, Department of Biology, Universidad Autónoma de Madrid, Cantoblanco, ES-28049 Madrid, Spain
| | - Carolina Escobar
- Department of Environmental Sciences, Universidad de Castilla-La Mancha, Campus Fábrica de Armas, ES-45070 Toledo, Spain
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Matern S, Peskan-Berghoefer T, Gromes R, Kiesel RV, Rausch T. Imposed glutathione-mediated redox switch modulates the tobacco wound-induced protein kinase and salicylic acid-induced protein kinase activation state and impacts on defence against Pseudomonas syringae. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:1935-50. [PMID: 25628332 PMCID: PMC4378631 DOI: 10.1093/jxb/eru546] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/09/2014] [Accepted: 12/15/2014] [Indexed: 05/06/2023]
Abstract
The role of the redox-active tripeptide glutathione in plant defence against pathogens has been studied extensively; however, the impact of changes in cellular glutathione redox potential on signalling processes during defence reactions has remained elusive. This study explored the impact of elevated glutathione content on the cytosolic redox potential and on early defence signalling at the level of mitogen-activated protein kinases (MAPKs), as well as on subsequent defence reactions, including changes in salicylic acid (SA) content, pathogenesis-related gene expression, callose depositions, and the hypersensitive response. Wild-type (WT) Nicotiana tabacum L. and transgenic high-glutathione lines (HGL) were transformed with the cytosol-targeted sensor GRX1-roGFP2 to monitor the cytosolic redox state. Surprisingly, HGLs displayed an oxidative shift in their cytosolic redox potential and an activation of the tobacco MAPKs wound-induced protein kinase (WIPK) and SA-induced protein kinase (SIPK). This activation occurred in the absence of any change in free SA content, but was accompanied by constitutively increased expression of several defence genes. Similarly, rapid activation of MAPKs could be induced in WT tobacco by exposure to either reduced or oxidized glutathione. When HGL plants were challenged with adapted or non-adapted Pseudomonas syringae pathovars, the cytosolic redox shift was further amplified and the defence response was markedly increased, showing a priming effect for SA and callose; however, the initial and transient hyperactivation of MAPK signalling was attenuated in HGLs. The results suggest that, in tobacco, MAPK and SA signalling may operate independently, both possibly being modulated by the glutathione redox potential. Possible mechanisms for redox-mediated MAPK activation are discussed.
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Affiliation(s)
- Sanja Matern
- Centre for Organismal Studies Heidelberg, Department of Plant Molecular Physiology, Heidelberg University, 69120 Heidelberg, Germany The Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology (HBIGS), Heidelberg University, 69120 Heidelberg, Germany
| | - Tatjana Peskan-Berghoefer
- Centre for Organismal Studies Heidelberg, Department of Plant Molecular Physiology, Heidelberg University, 69120 Heidelberg, Germany
| | - Roland Gromes
- Centre for Organismal Studies Heidelberg, Department of Plant Molecular Physiology, Heidelberg University, 69120 Heidelberg, Germany
| | - Rebecca Vazquez Kiesel
- Centre for Organismal Studies Heidelberg, Department of Plant Molecular Physiology, Heidelberg University, 69120 Heidelberg, Germany
| | - Thomas Rausch
- Centre for Organismal Studies Heidelberg, Department of Plant Molecular Physiology, Heidelberg University, 69120 Heidelberg, Germany
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Wang Y, Zhao W, Hao J, Xu W, Luo Y, Wu W, Yang Z, Liang Z, Huang K. Changes in biosynthesis and metabolism of glutathione upon ochratoxin A stress in Arabidopsis thaliana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 79:10-18. [PMID: 24662377 DOI: 10.1016/j.plaphy.2014.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 03/01/2014] [Indexed: 06/03/2023]
Abstract
Ochratoxin A (OTA) is one of the most toxic mycotoxins, which is toxic to plants and simulates oxidative stress. Glutathione is an important antioxidant in plants and is closely associated with detoxification in cells. We have previously shown that OTA exposure induces obvious expression differences in genes associated with glutathione metabolism. To characterize glutathione metabolism and understand its role in OTA phytotoxicity, we observed the accumulation of GSH in the detached leaves of Arabidopsis thaliana under OTA treatment. OTA stimulated a defense response through enhancing glutathione-S-transferase, glutathione peroxidase, glutathione reductase activities, and the transcript levels of these enzymes were increased to maintain the total glutathione content. Moreover, the level of oxidized glutathione (GSSG) was increased and the ascorbate-glutathione cycle fluctuated in response to OTA. The depletion of glutathione using buthionine sulfoximine (BSO, inhibitor of glutamate-cysteine ligase) had no profound effect on OTA toxicity, as glutathione was regenerated through the ascorbate-glutathione cycle to maintain the total glutathione content. The ROS, MDA and GSH accumulation was significantly affected in the mutant gsh1, gr1 and gpx2 after treatment with OTA, which indicated that glutathione metabolism is directly involved in the oxidative stress response of Arabidopsis thaliana subjected to OTA. In conclusion, date demonstrate that glutathione-associated metabolism is closely related with OTA stress and glutathione play a role in resistance of Arabidopsis subjected to OTA.
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Affiliation(s)
- Yan Wang
- Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China; Institute of Agro-products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Weiwei Zhao
- Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China
| | - Junran Hao
- Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China
| | - Wentao Xu
- Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China; The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, PR China.
| | - Yunbo Luo
- Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China; The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, PR China
| | - Weihong Wu
- Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China
| | - Zhuojun Yang
- The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, PR China
| | - Zhihong Liang
- The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, PR China
| | - Kunlun Huang
- Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China; The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, PR China
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Preuss ML, Cameron JC, Berg RH, Jez JM. Immunolocalization of glutathione biosynthesis enzymes in Arabidopsis thaliana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 75:9-13. [PMID: 24361505 DOI: 10.1016/j.plaphy.2013.11.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Accepted: 11/28/2013] [Indexed: 05/12/2023]
Abstract
In plants, glutathione serves as a versatile redox buffer and cellular protective compound against a range of biotic and abiotic stresses. Glutathione production involves glutamate-cysteine ligase (GCL), the redox-regulated limiting enzyme of the pathway, and glutathione synthetase (GS). Because the sub-cellular and sub-organellar localization of these enzymes will have an impact on metabolism, here we examine the localization of GCL and GS in the leaves of Arabidopsis thaliana. Immuno-electron microscopy of leaf cells indicates localization of GCL primarily to the chloroplast with GS found in both the chloroplast and cytosol. Detailed examination of the localization of both enzymes within chloroplasts was performed using fractionation followed by immunoblot analysis and indicates that GCL and GS are found in the stroma. The localization of these enzymes to the stroma of chloroplasts has implications for the redox-regulation of GCL and plant glutathione biosynthesis.
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Affiliation(s)
- Mary L Preuss
- Department of Biological Sciences, Webster University, 470 East Lockwood Ave., WEBH 9A, Webster Groves, MO 63119, USA
| | - Jeffrey C Cameron
- Department of Biology, Washington University, One Brookings Drive, Campus Box 1137, St. Louis, MO 63130, USA
| | - R Howard Berg
- Donald Danforth Plant Science Center, 975 North Warson Rd., St. Louis, MO 63132, USA
| | - Joseph M Jez
- Department of Biology, Washington University, One Brookings Drive, Campus Box 1137, St. Louis, MO 63130, USA.
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Rahantaniaina MS, Tuzet A, Mhamdi A, Noctor G. Missing links in understanding redox signaling via thiol/disulfide modulation: how is glutathione oxidized in plants? FRONTIERS IN PLANT SCIENCE 2013; 4:477. [PMID: 24324478 PMCID: PMC3838956 DOI: 10.3389/fpls.2013.00477] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/04/2013] [Indexed: 05/06/2023]
Abstract
Glutathione is a small redox-active molecule existing in two main stable forms: the thiol (GSH) and the disulphide (GSSG). In plants growing in optimal conditions, the GSH:GSSG ratio is high in most cell compartments. Challenging environmental conditions are known to alter this ratio, notably by inducing the accumulation of GSSG, an effect that may be influential in the perception or transduction of stress signals. Despite the potential importance of glutathione status in redox signaling, the reactions responsible for the oxidation of GSH to GSSG have not been clearly identified. Most attention has focused on the ascorbate-glutathione pathway, but several other candidate pathways may couple the availability of oxidants such as H2O2 to changes in glutathione and thus impact on signaling pathways through regulation of protein thiol-disulfide status. We provide an overview of the main candidate pathways and discuss the available biochemical, transcriptomic, and genetic evidence relating to each. Our analysis emphasizes how much is still to be elucidated on this question, which is likely important for a full understanding of how stress-related redox regulation might impinge on phytohormone-related and other signaling pathways in plants.
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Affiliation(s)
- Marie-Sylviane Rahantaniaina
- Institut de Biologie des Plantes, Université Paris-SudOrsay, France
- Institut National de Recherche Agronomique, UMR Environnement et Grandes CulturesThiverval-Grignon, France
| | - Andrée Tuzet
- Institut National de Recherche Agronomique, UMR Environnement et Grandes CulturesThiverval-Grignon, France
| | - Amna Mhamdi
- Institut de Biologie des Plantes, Université Paris-SudOrsay, France
| | - Graham Noctor
- Institut de Biologie des Plantes, Université Paris-SudOrsay, France
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29
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Han Y, Chaouch S, Mhamdi A, Queval G, Zechmann B, Noctor G. Functional analysis of Arabidopsis mutants points to novel roles for glutathione in coupling H(2)O(2) to activation of salicylic acid accumulation and signaling. Antioxid Redox Signal 2013; 18:2106-21. [PMID: 23148658 PMCID: PMC3629853 DOI: 10.1089/ars.2012.5052] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 11/11/2012] [Indexed: 01/08/2023]
Abstract
AIMS Through its interaction with H(2)O(2), glutathione is a candidate for transmission of signals in plant responses to pathogens, but identification of signaling roles is complicated by its antioxidant function. Using a genetic approach based on a conditional catalase-deficient Arabidopsis mutant, cat2, this study aimed at establishing whether GSH plays an important functional role in the transmission of signals downstream of H(2)O(2). RESULTS Introducing the cad2 or allelic mutations in the glutathione synthesis pathway into cat2 blocked H(2)O(2)-triggered GSH oxidation and accumulation. While no effects on NADP(H) or ascorbate were observed, and H(2)O(2)-induced decreases in growth were maintained, blocking GSH modulation antagonized salicylic acid (SA) accumulation and SA-dependent responses. Other novel double and triple mutants were produced and compared with cat2 cad2 at the levels of phenotype, expression of marker genes, nontargeted metabolite profiling, accumulation of SA, and bacterial resistance. Most of the effects of the cad2 mutation on H(2)O(2)-triggered responses were distinct from those produced by mutations for GLUTATHIONE REDUCTASE1 (GR1) or NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), and were linked to compromised induction of ISOCHORISMATE SYNTHASE1 (ICS1) and ICS1-dependent SA accumulation. INNOVATION A novel genetic approach was used in which GSH content or antioxidative capacity was independently modified in an H(2)O(2) signaling background. Analysis of new double and triple mutants allowed us to infer previously undescribed regulatory roles for GSH. CONCLUSION In parallel to its antioxidant role, GSH acts independently of NPR1 to allow increased intracellular H(2)O(2) to activate SA signaling, a key defense response in plants.
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Affiliation(s)
- Yi Han
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris Sud, Orsay Cedex, France
| | - Sejir Chaouch
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris Sud, Orsay Cedex, France
| | - Amna Mhamdi
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris Sud, Orsay Cedex, France
| | - Guillaume Queval
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris Sud, Orsay Cedex, France
| | - Bernd Zechmann
- Institute of Plant Sciences, University of Graz, Graz, Austria
| | - Graham Noctor
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris Sud, Orsay Cedex, France
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Probing the origins of glutathione biosynthesis through biochemical analysis of glutamate-cysteine ligase and glutathione synthetase from a model photosynthetic prokaryote. Biochem J 2013; 450:63-72. [PMID: 23170977 DOI: 10.1042/bj20121332] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glutathione biosynthesis catalysed by GCL (glutamate-cysteine ligase) and GS (glutathione synthetase) is essential for maintaining redox homoeostasis and protection against oxidative damage in diverse eukaroytes and bacteria. This biosynthetic pathway probably evolved in cyanobacteria with the advent of oxygenic photosynthesis, but the biochemical characteristics of progenitor GCLs and GSs in these organisms are largely unexplored. In the present study we examined SynGCL and SynGS from Synechocystis sp. PCC 6803 using steady-state kinetics. Although SynGCL shares ~15% sequence identity with the enzyme from plants and α-proteobacteria, sequence comparison suggests that these enzymes share similar active site residues. Biochemically, SynGCL lacks the redox regulation associated with the plant enzymes and functions as a monomeric protein, indicating that evolution of redox regulation occurred later in the green lineage. Site-directed mutagenesis of SynGCL establishes this enzyme as part of the plant-like GCL family and identifies a catalytically essential arginine residue, which is structurally conserved across all forms of GCLs, including those from non-plant eukaryotes and γ-proteobacteria. A reaction mechanism for the synthesis of γ-glutamylcysteine by GCLs is proposed. Biochemical and kinetic analysis of SynGS reveals that this enzyme shares properties with other prokaryotic GSs. Initial velocity and product inhibition studies used to examine the kinetic mechanism of SynGS suggest that it and other prokaryotic GSs uses a random ter-reactant mechanism for the synthesis of glutathione. The present study provides new insight on the molecular mechanisms and evolution of glutathione biosynthesis; a key process required for enhancing bioenergy production in photosynthetic organisms.
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31
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Redox-dependent stability of the γ-glutamylcysteine synthetase enzyme of Escherichia coli: a novel means of redox regulation. Biochem J 2013; 449:783-94. [DOI: 10.1042/bj20120204] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glutathione is a thiol-containing tripeptide that plays important roles in redox-related processes. The first step in glutathione biosynthesis is catalysed by γ-GCS (γ-glutamylcysteine synthetase). The crystal structure of Escherichia coli γ-GCS has revealed the presence of a disulfide bond. As the disulfide-bonding cysteine residues Cys372 and Cys395 are not well conserved among γ-GCS enzymes in this lineage, we have initiated a biochemical genetic strategy to investigate the functional importance of these and other cysteine residues. In a cysteine-free γ-GCS that was non-functional, suppressor analysis yielded combinations of cysteine and aromatic residues at the position of the disulfide bond, and one mutant that lacked any cysteine residues. Kinetic analysis of the wild-type and mutant enzymes revealed that the disulfide bond was not involved in determining the affinity of the enzyme towards its substrate, but had an important role in determining the stability of the protein, and its catalytic efficiency. We show that in vivo the γ-GCS enzyme can also exist in a reduced form and that the mutants lacking the disulfide bond show a decreased half-life. These results demonstrate a novel means of regulation of γ-GCS by the redox environment that works by an alteration in its stability.
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32
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Chan KX, Wirtz M, Phua SY, Estavillo GM, Pogson BJ. Balancing metabolites in drought: the sulfur assimilation conundrum. TRENDS IN PLANT SCIENCE 2013; 18:18-29. [PMID: 23040678 DOI: 10.1016/j.tplants.2012.07.005] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 07/27/2012] [Accepted: 07/30/2012] [Indexed: 05/18/2023]
Abstract
A key plant response to drought is the accumulation of specific sets of metabolites that act as osmoprotectants, osmolytes, antioxidants, and/or stress signals. An emerging question is: how do plants regulate metabolism to balance the 'competing interests' between metabolites during stress? Recent research connects primary sulfur metabolism (e.g., sulfate transport in the vasculature, its assimilation in leaves, and the recycling of sulfur-containing compounds) with the drought stress response. In this review, we highlight key steps in sulfur metabolism that play significant roles in drought stress signaling and responses. We propose that a complex balancing act is required to coordinate primary and secondary sulfur metabolism during the drought stress response in plants.
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Affiliation(s)
- Kai Xun Chan
- ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
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García-Giménez JL, Markovic J, Dasí F, Queval G, Schnaubelt D, Foyer CH, Pallardó FV. Nuclear glutathione. Biochim Biophys Acta Gen Subj 2012; 1830:3304-16. [PMID: 23069719 DOI: 10.1016/j.bbagen.2012.10.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/21/2012] [Accepted: 10/08/2012] [Indexed: 12/24/2022]
Abstract
Glutathione (GSH) is a linchpin of cellular defences in plants and animals with physiologically-important roles in the protection of cells from biotic and abiotic stresses. Moreover, glutathione participates in numerous metabolic and cell signalling processes including protein synthesis and amino acid transport, DNA repair and the control of cell division and cell suicide programmes. While it is has long been appreciated that cellular glutathione homeostasis is regulated by factors such as synthesis, degradation, transport, and redox turnover, relatively little attention has been paid to the influence of the intracellular partitioning on glutathione and its implications for the regulation of cell functions and signalling. We focus here on the functions of glutathione in the nucleus, particularly in relation to physiological processes such as the cell cycle and cell death. The sequestration of GSH in the nucleus of proliferating animal and plant cells suggests that common redox mechanisms exist for DNA regulation in G1 and mitosis in all eukaryotes. We propose that glutathione acts as "redox sensor" at the onset of DNA synthesis with roles in maintaining the nuclear architecture by providing the appropriate redox environment for the DNA replication and safeguarding DNA integrity. In addition, nuclear GSH may be involved in epigenetic phenomena and in the control of nuclear protein degradation by nuclear proteasome. Moreover, by increasing the nuclear GSH pool and reducing disulfide bonds on nuclear proteins at the onset of cell proliferation, an appropriate redox environment is generated for the stimulation of chromatin decompaction. This article is part of a Special Issue entitled Cellular functions of glutathione.
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Clemente MR, Bustos-Sanmamed P, Loscos J, James EK, Pérez-Rontomé C, Navascués J, Gay M, Becana M. Thiol synthetases of legumes: immunogold localization and differential gene regulation by phytohormones. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3923-34. [PMID: 22442424 PMCID: PMC3388825 DOI: 10.1093/jxb/ers083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 02/21/2012] [Accepted: 02/22/2012] [Indexed: 05/04/2023]
Abstract
In plants and other organisms, glutathione (GSH) biosynthesis is catalysed sequentially by γ-glutamylcysteine synthetase (γECS) and glutathione synthetase (GSHS). In legumes, homoglutathione (hGSH) can replace GSH and is synthesized by γECS and a specific homoglutathione synthetase (hGSHS). The subcellular localization of the enzymes was examined by electron microscopy in several legumes and gene expression was analysed in Lotus japonicus plants treated for 1-48 h with 50 μM of hormones. Immunogold localization studies revealed that γECS is confined to chloroplasts and plastids, whereas hGSHS is also in the cytosol. Addition of hormones caused differential expression of thiol synthetases in roots. After 24-48 h, abscisic and salicylic acids downregulated GSHS whereas jasmonic acid upregulated it. Cytokinins and polyamines activated GSHS but not γECS or hGSHS. Jasmonic acid elicited a coordinated response of the three genes and auxin induced both hGSHS expression and activity. Results show that the thiol biosynthetic pathway is compartmentalized in legumes. Moreover, the similar response profiles of the GSH and hGSH contents in roots of non-nodulated and nodulated plants to the various hormonal treatments indicate that thiol homeostasis is independent of the nitrogen source of the plants. The differential regulation of the three mRNA levels, hGSHS activity, and thiol contents by hormones indicates a fine control of thiol biosynthesis at multiple levels and strongly suggests that GSH and hGSH play distinct roles in plant development and stress responses.
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Affiliation(s)
- Maria R. Clemente
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 13034, 50080 Zaragoza, Spain
| | - Pilar Bustos-Sanmamed
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 13034, 50080 Zaragoza, Spain
| | - Jorge Loscos
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 13034, 50080 Zaragoza, Spain
| | - Euan K. James
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Carmen Pérez-Rontomé
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 13034, 50080 Zaragoza, Spain
| | - Joaquín Navascués
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 13034, 50080 Zaragoza, Spain
| | - Marina Gay
- CSIC-UAB Proteomics Laboratory, Instituto de Investigaciones Biomédicas de Barcelona-CSIC, 08193 Bellaterra, Spain
| | - Manuel Becana
- Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Apartado 13034, 50080 Zaragoza, Spain
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35
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Jobe TO, Sung DY, Akmakjian G, Pham A, Komives EA, Mendoza-Cózatl DG, Schroeder JI. Feedback inhibition by thiols outranks glutathione depletion: a luciferase-based screen reveals glutathione-deficient γ-ECS and glutathione synthetase mutants impaired in cadmium-induced sulfate assimilation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:783-95. [PMID: 22283708 PMCID: PMC4688143 DOI: 10.1111/j.1365-313x.2012.04924.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Plants exposed to heavy metals rapidly induce changes in gene expression that activate and enhance detoxification mechanisms, including toxic-metal chelation and the scavenging of reactive oxygen species. However, the mechanisms mediating toxic heavy metal-induced gene expression remain largely unknown. To genetically elucidate cadmium-specific transcriptional responses in Arabidopsis, we designed a genetic screen based on the activation of a cadmium-inducible reporter gene. Microarray studies identified a high-affinity sulfate transporter (SULTR1;2) among the most robust and rapid cadmium-inducible transcripts. The SULTR1;2 promoter (2.2 kb) was fused with the firefly luciferase reporter gene to quantitatively report the transcriptional response of plants exposed to cadmium. Stably transformed luciferase reporter lines were ethyl methanesulfonate (EMS) mutagenized, and stable M(2) seedlings were screened for an abnormal luciferase response during exposure to cadmium. The screen identified non-allelic mutant lines that fell into one of three categories: (i) super response to cadmium (SRC) mutants; (ii) constitutive response to cadmium (CRC) mutants; or (iii) non-response and reduced response to cadmium (NRC) mutants. Two nrc mutants, nrc1 and nrc2, were mapped, cloned and further characterized. The nrc1 mutation was mapped to the γ-glutamylcysteine synthetase gene and the nrc2 mutation was identified as the first viable recessive mutant allele in the glutathione synthetase gene. Moreover, genetic, HPLC mass spectrometry, and gene expression analysis of the nrc1 and nrc2 mutants, revealed that intracellular glutathione depletion alone would be insufficient to induce gene expression of sulfate uptake and assimilation mechanisms. Our results modify the glutathione-depletion driven model for sulfate assimilation gene induction during cadmium stress, and suggest that an enhanced oxidative state and depletion of upstream thiols, in addition to glutathione depletion, are necessary to induce the transcription of sulfate assimilation genes during early cadmium stress.
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Affiliation(s)
- Timothy O. Jobe
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
| | - Dong-Yul Sung
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
| | - Garo Akmakjian
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
| | - Allis Pham
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
| | - Elizabeth A. Komives
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0378, USA
| | - David G. Mendoza-Cózatl
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
- Division of Plant Sciences, C. S. Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211-7310, USA
| | - Julian I. Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093-0116, USA
- For correspondence ()
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Szarka A, Tomasskovics B, Bánhegyi G. The ascorbate-glutathione-α-tocopherol triad in abiotic stress response. Int J Mol Sci 2012; 13:4458-4483. [PMID: 22605990 PMCID: PMC3344226 DOI: 10.3390/ijms13044458] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Revised: 03/22/2012] [Accepted: 03/26/2012] [Indexed: 12/02/2022] Open
Abstract
The life of any living organism can be defined as a hurdle due to different kind of stresses. As with all living organisms, plants are exposed to various abiotic stresses, such as drought, salinity, extreme temperatures and chemical toxicity. These primary stresses are often interconnected, and lead to the overproduction of reactive oxygen species (ROS) in plants, which are highly reactive and toxic and cause damage to proteins, lipids, carbohydrates and DNA, which ultimately results in oxidative stress. Stress-induced ROS accumulation is counteracted by enzymatic antioxidant systems and non-enzymatic low molecular weight metabolites, such as ascorbate, glutathione and α-tocopherol. The above mentioned low molecular weight antioxidants are also capable of chelating metal ions, reducing thus their catalytic activity to form ROS and also scavenge them. Hence, in plant cells, this triad of low molecular weight antioxidants (ascorbate, glutathione and α-tocopherol) form an important part of abiotic stress response. In this work we are presenting a review of abiotic stress responses connected to these antioxidants.
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Affiliation(s)
- András Szarka
- Laboratory of Biochemistry and Molecular Biology, Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, 1111 Szent Gellért tér 4, Budapest, Hungary; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +36-1-463-3858; Fax: +36-1-463-3855
| | - Bálint Tomasskovics
- Laboratory of Biochemistry and Molecular Biology, Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, 1111 Szent Gellért tér 4, Budapest, Hungary; E-Mail:
| | - Gábor Bánhegyi
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry Pathobiochemistry, Research Group of Hungarian Academy of Sciences and Semmelweis University, 1444 Budapest, POB 260, Hungary; E-Mail:
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Jozefczak M, Remans T, Vangronsveld J, Cuypers A. Glutathione is a key player in metal-induced oxidative stress defenses. Int J Mol Sci 2012; 13:3145-3175. [PMID: 22489146 PMCID: PMC3317707 DOI: 10.3390/ijms13033145] [Citation(s) in RCA: 430] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/10/2012] [Accepted: 02/23/2012] [Indexed: 01/15/2023] Open
Abstract
Since the industrial revolution, the production, and consequently the emission of metals, has increased exponentially, overwhelming the natural cycles of metals in many ecosystems. Metals display a diverse array of physico-chemical properties such as essential versus non-essential and redox-active versus non-redox-active. In general, all metals can lead to toxicity and oxidative stress when taken up in excessive amounts, imposing a serious threat to the environment and human health. In order to cope with different kinds of metals, plants possess defense strategies in which glutathione (GSH; γ-glu-cys-gly) plays a central role as chelating agent, antioxidant and signaling component. Therefore, this review highlights the role of GSH in: (1) metal homeostasis; (2) antioxidative defense; and (3) signal transduction under metal stress. The diverse functions of GSH originate from the sulfhydryl group in cysteine, enabling GSH to chelate metals and participate in redox cycling.
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Affiliation(s)
- Marijke Jozefczak
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mails: (M.J.); (T.R.); (J.V.)
| | - Tony Remans
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mails: (M.J.); (T.R.); (J.V.)
| | - Jaco Vangronsveld
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mails: (M.J.); (T.R.); (J.V.)
| | - Ann Cuypers
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mails: (M.J.); (T.R.); (J.V.)
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Noctor G, Mhamdi A, Chaouch S, Han Y, Neukermans J, Marquez-Garcia B, Queval G, Foyer CH. Glutathione in plants: an integrated overview. PLANT, CELL & ENVIRONMENT 2012; 35:454-84. [PMID: 21777251 DOI: 10.1111/j.1365-3040.2011.02400.x] [Citation(s) in RCA: 791] [Impact Index Per Article: 65.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plants cannot survive without glutathione (γ-glutamylcysteinylglycine) or γ-glutamylcysteine-containing homologues. The reasons why this small molecule is indispensable are not fully understood, but it can be inferred that glutathione has functions in plant development that cannot be performed by other thiols or antioxidants. The known functions of glutathione include roles in biosynthetic pathways, detoxification, antioxidant biochemistry and redox homeostasis. Glutathione can interact in multiple ways with proteins through thiol-disulphide exchange and related processes. Its strategic position between oxidants such as reactive oxygen species and cellular reductants makes the glutathione system perfectly configured for signalling functions. Recent years have witnessed considerable progress in understanding glutathione synthesis, degradation and transport, particularly in relation to cellular redox homeostasis and related signalling under optimal and stress conditions. Here we outline the key recent advances and discuss how alterations in glutathione status, such as those observed during stress, may participate in signal transduction cascades. The discussion highlights some of the issues surrounding the regulation of glutathione contents, the control of glutathione redox potential, and how the functions of glutathione and other thiols are integrated to fine-tune photorespiratory and respiratory metabolism and to modulate phytohormone signalling pathways through appropriate modification of sensitive protein cysteine residues.
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Affiliation(s)
- Graham Noctor
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris sud 11, Orsay cedex, France.
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Ravilious GE, Jez JM. Structural biology of plant sulfur metabolism: From assimilation to biosynthesis. Nat Prod Rep 2012; 29:1138-52. [DOI: 10.1039/c2np20009k] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Structural basis and evolution of redox regulation in plant adenosine-5'-phosphosulfate kinase. Proc Natl Acad Sci U S A 2011; 109:309-14. [PMID: 22184237 DOI: 10.1073/pnas.1115772108] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Adenosine-5'-phosphosulfate (APS) kinase (APSK) catalyzes the phosphorylation of APS to 3'-phospho-APS (PAPS). In Arabidopsis thaliana, APSK is essential for reproductive viability and competes with APS reductase to partition sulfate between the primary and secondary branches of the sulfur assimilatory pathway; however, the biochemical regulation of APSK is poorly understood. The 1.8-Å resolution crystal structure of APSR from A. thaliana (AtAPSK) in complex with β,γ-imidoadenosine-5'-triphosphate, Mg(2+), and APS provides a view of the Michaelis complex for this enzyme and reveals the presence of an intersubunit disulfide bond between Cys86 and Cys119. Functional analysis of AtAPSK demonstrates that reduction of Cys86-Cys119 resulted in a 17-fold higher k(cat)/K(m) and a 15-fold increase in K(i) for substrate inhibition by APS compared with the oxidized enzyme. The C86A/C119A mutant was kinetically similar to the reduced WT enzyme. Gel- and activity-based titrations indicate that the midpoint potential of the disulfide in AtAPSK is comparable to that observed in APS reductase. Both cysteines are invariant among the APSK from plants, but not other organisms, which suggests redox-control as a unique regulatory feature of the plant APSK. Based on structural, functional, and sequence analyses, we propose that the redox-sensitive APSK evolved after bifurcation of the sulfur assimilatory pathway in the green plant lineage and that changes in redox environment resulting from oxidative stresses may affect partitioning of APS into the primary and secondary thiol metabolic routes by having opposing effects on APSK and APS reductase in plants.
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Dubreuil-Maurizi C, Vitecek J, Marty L, Branciard L, Frettinger P, Wendehenne D, Meyer AJ, Mauch F, Poinssot B. Glutathione deficiency of the Arabidopsis mutant pad2-1 affects oxidative stress-related events, defense gene expression, and the hypersensitive response. PLANT PHYSIOLOGY 2011; 157:2000-12. [PMID: 22007023 PMCID: PMC3327178 DOI: 10.1104/pp.111.182667] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 10/15/2011] [Indexed: 05/18/2023]
Abstract
The Arabidopsis (Arabidopsis thaliana) phytoalexin-deficient mutant pad2-1 displays enhanced susceptibility to a broad range of pathogens and herbivorous insects that correlates with deficiencies in the production of camalexin, indole glucosinolates, and salicylic acid (SA). The pad2-1 mutation is localized in the GLUTAMATE-CYSTEINE LIGASE (GCL) gene encoding the first enzyme of glutathione biosynthesis. While pad2-1 glutathione deficiency is not caused by a decrease in GCL transcripts, analysis of GCL protein level revealed that pad2-1 plants contained only 48% of the wild-type protein amount. In contrast to the wild type, the oxidized form of GCL was dominant in pad2-1, suggesting a distinct redox environment. This finding was corroborated by the expression of GRX1-roGFP2, showing that the cytosolic glutathione redox potential was significantly less negative in pad2-1. Analysis of oxidative stress-related gene expression showed a higher transcript accumulation in pad2-1 of GLUTATHIONE REDUCTASE, GLUTATHIONE-S-TRANSFERASE, and RESPIRATORY BURST OXIDASE HOMOLOG D in response to the oomycete Phytophthora brassicae. Interestingly, oligogalacturonide elicitation in pad2-1 revealed a lower plasma membrane depolarization that was found to act upstream of an impaired hydrogen peroxide production. This impaired hydrogen peroxide production was also observed during pathogen infection and correlated with a reduced hypersensitive response in pad2-1. In addition, a lack of pathogen-triggered expression of the ISOCHORISMATE SYNTHASE1 gene, coding for the SA-biosynthetic enzyme isochorismate synthase, was identified as the cause of the SA deficiency in pad2-1. Together, our results indicate that the pad2-1 mutation is related to a decrease in GCL protein and that the resulting glutathione deficiency negatively affects important processes of disease resistance.
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Noctor G, Queval G, Mhamdi A, Chaouch S, Foyer CH. Glutathione. THE ARABIDOPSIS BOOK 2011; 9:e0142. [PMID: 22303267 PMCID: PMC3267239 DOI: 10.1199/tab.0142] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Glutathione is a simple sulfur compound composed of three amino acids and the major non-protein thiol in many organisms, including plants. The functions of glutathione are manifold but notably include redox-homeostatic buffering. Glutathione status is modulated by oxidants as well as by nutritional and other factors, and can influence protein structure and activity through changes in thiol-disulfide balance. For these reasons, glutathione is a transducer that integrates environmental information into the cellular network. While the mechanistic details of this function remain to be fully elucidated, accumulating evidence points to important roles for glutathione and glutathione-dependent proteins in phytohormone signaling and in defense against biotic stress. Work in Arabidopsis is beginning to identify the processes that govern glutathione status and that link it to signaling pathways. As well as providing an overview of the components that regulate glutathione homeostasis (synthesis, degradation, transport, and redox turnover), the present discussion considers the roles of this metabolite in physiological processes such as light signaling, cell death, and defense against microbial pathogen and herbivores.
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Affiliation(s)
- Graham Noctor
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris sud 11, 91405 Orsay cedex, France
| | - Guillaume Queval
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris sud 11, 91405 Orsay cedex, France
- Present address: Department of Plant Systems Biology, Flanders Institute for Biotechnology and Department of Plant Biotechnologyand Genetics, Gent University, 9052 Gent, Belgium
| | - Amna Mhamdi
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris sud 11, 91405 Orsay cedex, France
| | - Sejir Chaouch
- Institut de Biologie des Plantes, UMR CNRS 8618, Université de Paris sud 11, 91405 Orsay cedex, France
| | - Christine H. Foyer
- Centre for Plant Sciences, Faculty of Biology, University of Leeds, Leeds, LS2 9JT, UK
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Takahashi H, Kopriva S, Giordano M, Saito K, Hell R. Sulfur assimilation in photosynthetic organisms: molecular functions and regulations of transporters and assimilatory enzymes. ANNUAL REVIEW OF PLANT BIOLOGY 2011; 62:157-84. [PMID: 21370978 DOI: 10.1146/annurev-arplant-042110-103921] [Citation(s) in RCA: 462] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Sulfur is required for growth of all organisms and is present in a wide variety of metabolites having distinctive biological functions. Sulfur is cycled in ecosystems in nature where conversion of sulfate to organic sulfur compounds is primarily dependent on sulfate uptake and reduction pathways in photosynthetic organisms and microorganisms. In vascular plant species, transport proteins and enzymes in this pathway are functionally diversified to have distinct biochemical properties in specific cellular and subcellular compartments. Recent findings indicate regulatory processes of sulfate transport and metabolism are tightly connected through several modes of transcriptional and posttranscriptional mechanisms. This review provides up-to-date knowledge in functions and regulations of sulfur assimilation in plants and algae, focusing on sulfate transport systems and metabolic pathways for sulfate reduction and synthesis of downstream metabolites with diverse biological functions.
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Galant A, Preuss ML, Cameron JC, Jez JM. Plant glutathione biosynthesis: diversity in biochemical regulation and reaction products. FRONTIERS IN PLANT SCIENCE 2011; 2:45. [PMID: 22645536 PMCID: PMC3355797 DOI: 10.3389/fpls.2011.00045] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 08/16/2011] [Indexed: 05/19/2023]
Abstract
In plants, exposure to temperature extremes, heavy metal-contaminated soils, drought, air pollutants, and pathogens results in the generation of reactive oxygen species that alter the intracellular redox environment, which in turn influences signaling pathways and cell fate. As part of their response to these stresses, plants produce glutathione. Glutathione acts as an anti-oxidant by quenching reactive oxygen species, and is involved in the ascorbate-glutathione cycle that eliminates damaging peroxides. Plants also use glutathione for the detoxification of xenobiotics, herbicides, air pollutants (sulfur dioxide and ozone), and toxic heavy metals. Two enzymes catalyze glutathione synthesis: glutamate-cysteine ligase, and glutathione synthetase. Glutathione is a ubiquitous protective compound in plants, but the structural and functional details of the proteins that synthesize it, as well as the potential biochemical mechanisms of their regulation, have only begun to be explored. As discussed here, the core reactions of glutathione synthesis are conserved across various organisms, but plants have diversified both the regulatory mechanisms that control its synthesis and the range of products derived from this pathway. Understanding the molecular basis of glutathione biosynthesis and its regulation will expand our knowledge of this component in the plant stress response network.
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Affiliation(s)
- Ashley Galant
- Department of Biology, Washington University in St. LouisSt. Louis, MO, USA
| | - Mary L. Preuss
- Department of Biological Sciences, Webster UniversityWebster Groves, MO, USA
| | - Jeffrey C. Cameron
- Department of Biology, Washington University in St. LouisSt. Louis, MO, USA
| | - Joseph M. Jez
- Department of Biology, Washington University in St. LouisSt. Louis, MO, USA
- *Correspondence: Joseph M. Jez, Department of Biology, Washington University in St. Louis, One Brookings Drive, Campus Box 1137, St. Louis, MO 63130, USA. e-mail:
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45
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Yi H, Ravilious GE, Galant A, Krishnan HB, Jez JM. From sulfur to homoglutathione: thiol metabolism in soybean. Amino Acids 2010; 39:963-78. [PMID: 20364282 DOI: 10.1007/s00726-010-0572-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Accepted: 03/16/2010] [Indexed: 12/11/2022]
Abstract
Sulfur is an essential plant nutrient and is metabolized into the sulfur-containing amino acids (cysteine and methionine) and into molecules that protect plants against oxidative and environmental stresses. Although studies of thiol metabolism in the model plant Arabidopsis thaliana (thale cress) have expanded our understanding of these dynamic processes, our knowledge of how sulfur is assimilated and metabolized in crop plants, such as soybean (Glycine max), remains limited in comparison. Soybean is a major crop used worldwide for food and animal feed. Although soybeans are protein-rich, they do not contain high levels of the sulfur-containing amino acids, cysteine and methionine. Ultimately, unraveling the fundamental steps and regulation of thiol metabolism in soybean is important for optimizing crop yield and quality. Here we review the pathways from sulfur uptake to glutathione and homoglutathione synthesis in soybean, the potential biotechnology benefits of understanding and modifying these pathways, and how information from the soybean genome may guide the next steps in exploring this biochemical system.
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Affiliation(s)
- Hankuil Yi
- Department of Biology, Washington University, St. Louis, MO 63130, USA
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Liedschulte V, Wachter A, Zhigang A, Rausch T. Exploiting plants for glutathione (GSH) production: Uncoupling GSH synthesis from cellular controls results in unprecedented GSH accumulation. PLANT BIOTECHNOLOGY JOURNAL 2010; 8:807-20. [PMID: 20233332 DOI: 10.1111/j.1467-7652.2010.00510.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Glutathione (GSH) is a key factor for cellular redox homeostasis and tolerance against abiotic and biotic stress (May et al., 1998; Noctor et al., 1998a). Previous attempts to increase GSH content in plants have met with moderate success (Rennenberg et al., 2007), largely because of tight and multilevel control of its biosynthesis (Rausch et al., 2007). Here, we report the in planta expression of the bifunctional gamma-glutamylcysteine ligase-glutathione synthetase enzyme from Streptococcus thermophilus (StGCL-GS), which is shown to be neither redox-regulated nor sensitive to feedback inhibition by GSH. Transgenic tobacco plants expressing StGCL-GS under control of a constitutive promoter reveal an extreme accumulation of GSH in their leaves (up to 12 micromol GSH/gFW, depending on the developmental stage), which is more than 20- to 30-fold above the levels observed in wild-type (wt) plants and which can be even further increased by additional sulphate fertilization. Surprisingly, this dramatically increased GSH production has no impact on plant growth while enhancing plant tolerance to abiotic stress. Furthermore, StGCL-GS-expressing plants are a novel, cost-saving source for GSH production, being competitive with current yeast-based systems (Li et al., 2004).
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Yi H, Galant A, Ravilious GE, Preuss ML, Jez JM. Sensing sulfur conditions: simple to complex protein regulatory mechanisms in plant thiol metabolism. MOLECULAR PLANT 2010; 3:269-79. [PMID: 20080815 DOI: 10.1093/mp/ssp112] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Sulfur is essential for plant growth and development, and the molecular systems for maintaining sulfur and thiol metabolism are tightly controlled. From a biochemical perspective, the regulation of plant thiol metabolism highlights nature's ability to engineer pathways that respond to multiple inputs and cellular demands under a range of conditions. In this review, we focus on the regulatory mechanisms that form the molecular basis of biochemical sulfur sensing in plants by translating the intracellular concentration of sulfur-containing compounds into control of key metabolic steps. These mechanisms range from the simple (substrate availability, thermodynamic properties of reactions, feedback inhibition, and organelle localization) to the elaborate (formation of multienzyme complexes and thiol-based redox switches). Ultimately, the dynamic interplay of these regulatory systems is critical for sensing and maintaining sulfur assimilation and thiol metabolism in plants.
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Affiliation(s)
- Hankuil Yi
- Department of Biology, Washington University, St Louis, MO 63130, USA
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Franklin CC, Backos DS, Mohar I, White CC, Forman HJ, Kavanagh TJ. Structure, function, and post-translational regulation of the catalytic and modifier subunits of glutamate cysteine ligase. Mol Aspects Med 2008; 30:86-98. [PMID: 18812186 DOI: 10.1016/j.mam.2008.08.009] [Citation(s) in RCA: 487] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 08/28/2008] [Accepted: 08/29/2008] [Indexed: 11/28/2022]
Abstract
Glutathione (GSH) is a tripeptide composed of glutamate, cysteine, and glycine. The first and rate-limiting step in GSH synthesis is catalyzed by glutamate cysteine ligase (GCL, previously known as gamma-glutamylcysteine synthetase). GCL is a heterodimeric protein composed of catalytic (GCLC) and modifier (GCLM) subunits that are expressed from different genes. GCLC catalyzes a unique gamma-carboxyl linkage from glutamate to cysteine and requires ATP and Mg(++) as cofactors in this reaction. GCLM increases the V(max) and K(cat) of GCLC, decreases the K(m) for glutamate and ATP, and increases the K(i) for GSH-mediated feedback inhibition of GCL. While post-translational modifications of GCLC (e.g. phosphorylation, myristoylation, caspase-mediated cleavage) have modest effects on GCL activity, oxidative stress dramatically affects GCL holoenzyme formation and activity. Pyridine nucleotides can also modulate GCL activity in some species. Variability in GCL expression is associated with several disease phenotypes and transgenic mouse and rat models promise to be highly useful for investigating the relationships between GCL activity, GSH synthesis, and disease in humans.
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Affiliation(s)
- Christopher C Franklin
- Department of Pharmaceutical Sciences, University of Colorado Denver, Denver, CO 80262, USA.
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