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Fedorin DN, Eprintsev AT, Chuykova VO, Igamberdiev AU. Participation of miR165a in the Phytochrome Signal Transduction in Maize ( Zea mays L.) Leaves under Changing Light Conditions. Int J Mol Sci 2024; 25:5733. [PMID: 38891921 PMCID: PMC11171563 DOI: 10.3390/ijms25115733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/16/2024] [Accepted: 05/18/2024] [Indexed: 06/21/2024] Open
Abstract
The involvement of the microRNA miR165a in the light-dependent mechanisms of regulation of target genes in maize (Zea mays) has been studied. The light-induced change in the content of free miR165a was associated with its binding by the AGO10 protein and not with a change in the rate of its synthesis from the precursor. The use of knockout Arabidopsis plants for the phytochrome A and B genes demonstrated that the presence of an active form of phytochrome B causes an increase in the level of the RNA-induced silencing miR165a complex, which triggers the degradation of target mRNAs. The two fractions of vesicles from maize leaves, P40 and P100 that bind miR165a, were isolated by ultracentrifugation. The P40 fraction consisted of larger vesicles of the size >0.170 µm, while the P100 fraction vesicles were <0.147 µm. Based on the quantitative PCR data, the predominant location of miR165a on the surface of extracellular vesicles of both fractions was established. The formation of the active form of phytochrome upon the irradiation of maize plants with red light led to a redistribution of miR165a, resulting in an increase in its proportion inside P40 vesicles and a decrease in P100 vesicles.
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Affiliation(s)
- Dmitry N. Fedorin
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018 Voronezh, Russia; (D.N.F.); (A.T.E.); (V.O.C.)
| | - Alexander T. Eprintsev
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018 Voronezh, Russia; (D.N.F.); (A.T.E.); (V.O.C.)
| | - Victoria O. Chuykova
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018 Voronezh, Russia; (D.N.F.); (A.T.E.); (V.O.C.)
| | - Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
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Fedorin DN, Eprintsev AT, Igamberdiev AU. The role of promoter methylation of the genes encoding the enzymes metabolizing di- and tricarboxylic acids in the regulation of plant respiration by light. JOURNAL OF PLANT PHYSIOLOGY 2024; 294:154195. [PMID: 38377939 DOI: 10.1016/j.jplph.2024.154195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/04/2024] [Accepted: 02/12/2024] [Indexed: 02/22/2024]
Abstract
We discuss the role of epigenetic changes at the level of promoter methylation of the key enzymes of carbon metabolism in the regulation of respiration by light. While the direct regulation of enzymes via modulation of their activity and post-translational modifications is fast and readily reversible, the role of cytosine methylation is important for providing a prolonged response to environmental changes. In addition, adenine methylation can play a role in the regulation of transcription of genes. The mitochondrial and extramitochondrial forms of several enzymes participating in the tricarboxylic acid cycle and associated reactions are regulated via promoter methylation in opposite ways. The mitochondrial forms of citrate synthase, aconitase, fumarase, NAD-malate dehydrogenase are inhibited while the cytosolic forms of aconitase, fumarase, NAD-malate dehydrogenase, and the peroxisomal form of citrate synthase are activated. It is concluded that promoter methylation represents a universal mechanism of the regulation of activity of respiratory enzymes in plant cells by light. The role of the regulation of the mitochondrial and cytosolic forms of respiratory enzymes in the operation of malate and citrate valves and in controlling the redox state and balancing the energy level of photosynthesizing plant cells is discussed.
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Affiliation(s)
- Dmitry N Fedorin
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018, Voronezh, Russia.
| | - Alexander T Eprintsev
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018, Voronezh, Russia.
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada.
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Liu X, Zuo Z, Xie X, Gao S, Wu S, Gu W, Wang G. SLC24A-mediated calcium exchange as an indispensable component of the diatom cell density-driven signaling pathway. THE ISME JOURNAL 2024; 18:wrae039. [PMID: 38457651 PMCID: PMC10982851 DOI: 10.1093/ismejo/wrae039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/09/2024] [Accepted: 03/04/2024] [Indexed: 03/10/2024]
Abstract
Diatom bloom is characterized by a rapid increase of population density. Perception of population density and physiological responses can significantly influence their survival strategies, subsequently impacting bloom fate. The population density itself can serve as a signal, which is perceived through chemical signals or chlorophyll fluorescence signals triggered by high cell density, and their intracellular signaling mechanisms remain to be elucidated. In this study, we focused on the model diatom, Phaeodactylum tricornutum, and designed an orthogonal experiment involving varying cell densities and light conditions, to stimulate the release of chemical signals and light-induced chlorophyll fluorescence signals. Utilizing RNA-Seq and Weighted Gene Co-expression Network Analysis, we identified four gene clusters displaying density-dependent expression patterns. Within these, a potential hub gene, PtSLC24A, encoding a Na+/Ca2+ exchanger, was identified. Based on molecular genetics, cellular physiology, computational structural biology, and in situ oceanic data, we propose a potential intracellular signaling mechanism related to cell density in marine diatoms using Ca2+: upon sensing population density signals mediated by chemical cues, the membrane-bound PtSLC24A facilitates the efflux of Ca2+ to maintain specific intracellular calcium levels, allowing the transduction of intracellular density signals, subsequently regulating physiological responses, including cell apoptosis, ultimately affecting algal blooms fate. These findings shed light on the calcium-mediated intracellular signaling mechanism of marine diatoms to changing population densities, and enhances our understanding of diatom bloom dynamics and their ecological implications.
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Affiliation(s)
- Xuehua Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Zhicheng Zuo
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
- Shanghai Frontiers Science Research Center for Druggability of Cardiovascular Noncoding RNA, Institute for Frontier Medical Technology, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Xiujun Xie
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Shan Gao
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Songcui Wu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Wenhui Gu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Guangce Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
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Eprintsev AT, Fedorin DN, Igamberdiev AU. Light-Dependent Expression and Promoter Methylation of the Genes Encoding Succinate Dehydrogenase, Fumarase, and NAD-Malate Dehydrogenase in Maize ( Zea mays L.) Leaves. Int J Mol Sci 2023; 24:10211. [PMID: 37373359 DOI: 10.3390/ijms241210211] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/07/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
The expression and methylation of promoters of the genes encoding succinate dehydrogenase, fumarase, and NAD-malate dehydrogenase in maize (Zea mays L.) leaves depending on the light regime were studied. The genes encoding the catalytic subunits of succinate dehydrogenase showed suppression of expression upon irradiation by red light, which was abolished by far-red light. This was accompanied by an increase in promoter methylation of the gene Sdh1-2 encoding the flavoprotein subunit A, while methylation was low for Sdh2-3 encoding the iron-sulfur subunit B under all conditions. The expression of Sdh3-1 and Sdh4 encoding the anchoring subunits C and D was not affected by red light. The expression of Fum1 encoding the mitochondrial form of fumarase was regulated by red and far-red light via methylation of its promoter. Only one gene encoding the mitochondrial NAD-malate dehydrogenase gene (mMdh1) was regulated by red and far-red light, while the second gene (mMdh2) did not respond to irradiation, and neither gene was controlled by promoter methylation. It is concluded that the dicarboxylic branch of the tricarboxylic acid cycle is regulated by light via the phytochrome mechanism, and promoter methylation is involved with the flavoprotein subunit of succinate dehydrogenase and the mitochondrial fumarase.
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Affiliation(s)
- Alexander T Eprintsev
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018 Voronezh, Russia
| | - Dmitry N Fedorin
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018 Voronezh, Russia
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
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Daloso DDM, Morais EG, Oliveira E Silva KF, Williams TCR. Cell-type-specific metabolism in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:1093-1114. [PMID: 36987968 DOI: 10.1111/tpj.16214] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/20/2023] [Accepted: 03/25/2023] [Indexed: 05/31/2023]
Abstract
Every plant organ contains tens of different cell types, each with a specialized function. These functions are intrinsically associated with specific metabolic flux distributions that permit the synthesis of the ATP, reducing equivalents and biosynthetic precursors demanded by the cell. Investigating such cell-type-specific metabolism is complicated by the mosaic of different cells within each tissue combined with the relative scarcity of certain types. However, techniques for the isolation of specific cells, their analysis in situ by microscopy, or modeling of their function in silico have permitted insight into cell-type-specific metabolism. In this review we present some of the methods used in the analysis of cell-type-specific metabolism before describing what we know about metabolism in several cell types that have been studied in depth; (i) leaf source and sink cells; (ii) glandular trichomes that are capable of rapid synthesis of specialized metabolites; (iii) guard cells that must accumulate large quantities of the osmolytes needed for stomatal opening; (iv) cells of seeds involved in storage of reserves; and (v) the mesophyll and bundle sheath cells of C4 plants that participate in a CO2 concentrating cycle. Metabolism is discussed in terms of its principal features, connection to cell function and what factors affect the flux distribution. Demand for precursors and energy, availability of substrates and suppression of deleterious processes are identified as key factors in shaping cell-type-specific metabolism.
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Affiliation(s)
- Danilo de Menezes Daloso
- Lab Plant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza-CA, 60451-970, Brazil
| | - Eva Gomes Morais
- Lab Plant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza-CA, 60451-970, Brazil
| | - Karen Fernanda Oliveira E Silva
- Departamento de Botânica, Instituto de Ciências Biológicas, Universidade de Brasília, Asa Norte, Brasília-DF, 70910-900, Brazil
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Porto NP, Bret RSC, Souza PVL, Cândido-Sobrinho SA, Medeiros DB, Fernie AR, Daloso DM. Thioredoxins regulate the metabolic fluxes throughout the tricarboxylic acid cycle and associated pathways in a light-independent manner. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 193:36-49. [PMID: 36323196 DOI: 10.1016/j.plaphy.2022.10.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/11/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
The metabolic fluxes throughout the tricarboxylic acid cycle (TCAC) are inhibited in the light by the mitochondrial thioredoxin (TRX) system. However, it is unclear how this system orchestrates the fluxes throughout the TCAC and associated pathways in the dark. Here we carried out a13C-HCO3 labelling experiment in Arabidopsis leaves from wild type (WT) and mutants lacking TRX o1 (trxo1), TRX h2 (trxh2), or both NADPH-dependent TRX reductase A and B (ntra ntrb) exposed to 0, 30 and 60 min of dark or light conditions. No 13C-enrichment in TCAC metabolites in illuminated WT leaves was observed. However, increased succinate content was found in parallel to reductions in Ala in the light, suggesting the latter operates as an alternative carbon source for succinate synthesis. By contrast to WT, all mutants showed substantial changes in the content and 13C-enrichment in TCAC metabolites under both dark and light conditions. Increased 13C-enrichment in glutamine in illuminated trxo1 leaves was also observed, strengthening the idea that TRX o1 restricts in vivo carbon fluxes from glycolysis and the TCAC to glutamine. We further demonstrated that both photosynthetic and gluconeogenic fluxes toward glucose are increased in trxo1 and that the phosphoenolpyruvate carboxylase (PEPc)-mediated 13C-incorporation into malate is higher in trxh2 mutants, as compared to WT. Our results collectively provide evidence that TRX h2 and the mitochondrial NTR/TRX system regulate the metabolic fluxes throughout the TCAC and associated pathways, including glycolysis, gluconeogenesis and the synthesis of glutamine in a light-independent manner.
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Affiliation(s)
- Nicole P Porto
- LabPlant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60451-970, Fortaleza, Ceará, Brazil
| | - Raissa S C Bret
- LabPlant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60451-970, Fortaleza, Ceará, Brazil
| | - Paulo V L Souza
- LabPlant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60451-970, Fortaleza, Ceará, Brazil
| | - Silvio A Cândido-Sobrinho
- LabPlant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60451-970, Fortaleza, Ceará, Brazil
| | - David B Medeiros
- Max-Planck-Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
| | - Danilo M Daloso
- LabPlant, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60451-970, Fortaleza, Ceará, Brazil.
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7
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Eprintsev AT, Anokhina GB, Fedorin DN. Regulation of Glutamate Dehydrogenase Activity in Maize Leaves (Zea mays L.) with Change in the Light Сonditions. BIOL BULL+ 2021. [DOI: 10.1134/s1062359021060066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Duarte GT, Pandey PK, Vaid N, Alseekh S, Fernie AR, Nikoloski Z, Laitinen RAE. Plasticity of rosette size in response to nitrogen availability is controlled by an RCC1-family protein. PLANT, CELL & ENVIRONMENT 2021; 44:3398-3411. [PMID: 34228823 DOI: 10.1111/pce.14146] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 07/01/2021] [Accepted: 07/02/2021] [Indexed: 05/12/2023]
Abstract
Nitrogen (N) is fundamental to plant growth, development and yield. Genes underlying N utilization and assimilation are well-characterized, but mechanisms underpinning plasticity of different phenotypes in response to N remain elusive. Here, using Arabidopsis thaliana accessions, we dissected the genetic architecture of plasticity in early and late rosette diameter, flowering time and yield, in response to three levels of N in the soil. Furthermore, we found that the plasticity in levels of primary metabolites were related with the plasticities of the studied traits. Genome-wide association analysis identified three significant associations for phenotypic plasticity, one for early rosette diameter and two for flowering time. We confirmed that the gene At1g19880, hereafter named as PLASTICITY OF ROSETTE TO NITROGEN 1 (PROTON1), encoding for a regulator of chromatin condensation 1 (RCC1) family protein, conferred plasticity of rosette diameter in response to N. Treatment of PROTON1 T-DNA line with salt implied that the reduced plasticity of early rosette diameter was not a general growth response to stress. We further showed that plasticities of growth and flowering-related traits differed between environmental cues, indicating decoupled genetic programs regulating these traits. Our findings provide a prospective to identify genes that stabilize performance under fluctuating environments.
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Affiliation(s)
- Gustavo Turqueto Duarte
- Molecular Mechanisms of Plant Adaptation - group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
| | - Prashant K Pandey
- Molecular Mechanisms of Plant Adaptation - group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
- National Research Council Canada (NRC-CNRC), Aquatic and Crop Resource Development (ACRD), Saskatoon, Saskatchewan, Canada
| | - Neha Vaid
- Molecular Mechanisms of Plant Adaptation - group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
- Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Saleh Alseekh
- Central Metabolism - group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
- Department of Plant Metabolomics, Center of Plant Systems Biology, Plovdiv, Bulgaria
| | - Alisdair R Fernie
- Central Metabolism - group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
- Department of Plant Metabolomics, Center of Plant Systems Biology, Plovdiv, Bulgaria
| | - Zoran Nikoloski
- Systems Biology and Mathematical Modeling - group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
- Department of Bioinformatics and Mathematical Modeling, Center of Plant Systems Biology, Plovdiv, Bulgaria
- Bioinformatics, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Roosa A E Laitinen
- Molecular Mechanisms of Plant Adaptation - group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
- Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
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Eprintsev AT, Fedorin DN, Anokhina GB, Igamberdiev AU. Effects of light, anoxia and salinity on the expression of dihydroxyacid dehydratase in maize. JOURNAL OF PLANT PHYSIOLOGY 2021; 265:153507. [PMID: 34478919 DOI: 10.1016/j.jplph.2021.153507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/24/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Dihydroxyacid dehydratase (EC 4.2.1.9) participates in metabolism of branched chain amino acids, in CoA biosynthesis and in the conversion of hydroxycitric acid that accumulates in several plants. In maize (Zea mays L.), this enzyme is encoded by the two genes (Dhad1 and Dhad2), having different patterns of their expression during germination. We have demonstrated the inhibition of Dhad1 expression by light and the opposite effect of light on Dhad2. These effects were phytochrome-dependent and involved methylation/demethylation of promoters. Incubation of maize plants in a nitrogen atmosphere resulted in Dhad1 activation peaking at 12 h, which coincided with the decrease in promoter methylation. The gene Dhad2 was activated only during the first 6 h of anoxia, with no correlation with the level of promoter methylation. Salt stress (150 mM NaCl) caused the activation of expression of Dhad2 while the expression of Dhad1 was inhibited in the first hour and then after 12 h incubation with NaCl. We conclude that the expression of two genes encoding dihydroxyacid dehydratase reveals the opposite or different patterns of regulation by light, anoxia and salinity. The mechanisms underlying these modifications involve promoter methylation and result in corresponding changes in the enzymatic activity of the conversion of hydroxycitrate to 2-oxoglutarate.
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Affiliation(s)
- Alexander T Eprintsev
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018, Voronezh, Russia.
| | - Dmitry N Fedorin
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018, Voronezh, Russia.
| | - Galina B Anokhina
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394018, Voronezh, Russia.
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
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10
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da Fonseca-Pereira P, Souza PVL, Fernie AR, Timm S, Daloso DM, Araújo WL. Thioredoxin-mediated regulation of (photo)respiration and central metabolism. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5987-6002. [PMID: 33649770 DOI: 10.1093/jxb/erab098] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
Thioredoxins (TRXs) are ubiquitous proteins engaged in the redox regulation of plant metabolism. Whilst the light-dependent TRX-mediated activation of Calvin-Benson cycle enzymes is well documented, the role of extraplastidial TRXs in the control of the mitochondrial (photo)respiratory metabolism has been revealed relatively recently. Mitochondrially located TRX o1 has been identified as a regulator of alternative oxidase, enzymes of, or associated with, the tricarboxylic acid (TCA) cycle, and the mitochondrial dihydrolipoamide dehydrogenase (mtLPD) involved in photorespiration, the TCA cycle, and the degradation of branched chain amino acids. TRXs are seemingly a major point of metabolic regulation responsible for activating photosynthesis and adjusting mitochondrial photorespiratory metabolism according to the prevailing cellular redox status. Furthermore, TRX-mediated (de)activation of TCA cycle enzymes contributes to explain the non-cyclic flux mode of operation of this cycle in illuminated leaves. Here we provide an overview on the decisive role of TRXs in the coordination of mitochondrial metabolism in the light and provide in silico evidence for other redox-regulated photorespiratory enzymes. We further discuss the consequences of mtLPD regulation beyond photorespiration and provide outstanding questions that should be addressed in future studies to improve our understanding of the role of TRXs in the regulation of central metabolism.
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Affiliation(s)
| | - Paulo V L Souza
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Stefan Timm
- University of Rostock, Plant Physiology Department, Albert- Einstein-Str. 3, Rostock, Germany
| | - Danilo M Daloso
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
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11
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Effect of Salt Stress on the Expression and Promoter Methylation of the Genes Encoding the Mitochondrial and Cytosolic Forms of Aconitase and Fumarase in Maize. Int J Mol Sci 2021; 22:ijms22116012. [PMID: 34199464 PMCID: PMC8199617 DOI: 10.3390/ijms22116012] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/26/2021] [Accepted: 05/29/2021] [Indexed: 12/23/2022] Open
Abstract
The influence of salt stress on gene expression, promoter methylation, and enzymatic activity of the mitochondrial and cytosolic forms of aconitase and fumarase has been investigated in maize (Zea mays L.) seedlings. The incubation of maize seedlings in 150-mM NaCl solution resulted in a several-fold increase of the mitochondrial activities of aconitase and fumarase that peaked at 6 h of NaCl treatment, while the cytosolic activity of aconitase and fumarase decreased. This corresponded to the decrease in promoter methylation of the genes Aco1 and Fum1 encoding the mitochondrial forms of these enzymes and the increase in promoter methylation of the genes Aco2 and Fum2 encoding the cytosolic forms. The pattern of expression of the genes encoding the mitochondrial forms of aconitase and fumarase corresponded to the profile of the increase of the stress marker gene ZmCOI6.1. It is concluded that the mitochondrial and cytosolic forms of aconitase and fumarase are regulated via the epigenetic mechanism of promoter methylation of their genes in the opposite ways in response to salt stress. The role of the mitochondrial isoforms of aconitase and fumarase in the elevation of respiration under salt stress is discussed.
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12
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Rashid FAA, Scafaro AP, Asao S, Fenske R, Dewar RC, Masle J, Taylor NL, Atkin OK. Diel- and temperature-driven variation of leaf dark respiration rates and metabolite levels in rice. THE NEW PHYTOLOGIST 2020; 228:56-69. [PMID: 32415853 DOI: 10.1111/nph.16661] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
Leaf respiration in the dark (Rdark ) is often measured at a single time during the day, with hot-acclimation lowering Rdark at a common measuring temperature. However, it is unclear whether the diel cycle influences the extent of thermal acclimation of Rdark , or how temperature and time of day interact to influence respiratory metabolites. To examine these issues, we grew rice under 25°C : 20°C, 30°C : 25°C and 40°C : 35°C day : night cycles, measuring Rdark and changes in metabolites at five time points spanning a single 24-h period. Rdark differed among the treatments and with time of day. However, there was no significant interaction between time and growth temperature, indicating that the diel cycle does not alter thermal acclimation of Rdark . Amino acids were highly responsive to the diel cycle and growth temperature, and many were negatively correlated with carbohydrates and with organic acids of the tricarboxylic acid (TCA) cycle. Organic TCA intermediates were significantly altered by the diel cycle irrespective of growth temperature, which we attributed to light-dependent regulatory control of TCA enzyme activities. Collectively, our study shows that environmental disruption of the balance between respiratory substrate supply and demand is corrected for by shifts in TCA-dependent metabolites.
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Affiliation(s)
- Fatimah Azzahra Ahmad Rashid
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Department of Biology, Faculty of Science and Mathematics, Sultan Idris Education University, 35900 Tanjung Malim, Perak, Malaysia
| | - Andrew P Scafaro
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Shinichi Asao
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Ricarda Fenske
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences and Institute of Agriculture, Faculty of Science, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Roderick C Dewar
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Helsinki, Finland
| | - Josette Masle
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Nicolas L Taylor
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences and Institute of Agriculture, Faculty of Science, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Owen K Atkin
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
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13
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Igamberdiev AU. Citrate valve integrates mitochondria into photosynthetic metabolism. Mitochondrion 2020; 52:218-230. [PMID: 32278088 DOI: 10.1016/j.mito.2020.04.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 03/21/2020] [Accepted: 04/07/2020] [Indexed: 12/31/2022]
Abstract
While in heterotrophic cells and in darkness mitochondria serve as main producers of energy, during photosynthesis this function is transferred to chloroplasts and the main role of mitochondria in bioenergetics turns to be the balance of the level of phosphorylation of adenylates and of reduction of pyridine nucleotides to avoid over-energization of the cell and optimize major metabolic fluxes. This is achieved via the establishment and regulation of local equilibria of the tricarboxylic acid (TCA) cycle enzymes malate dehydrogenase and fumarase in one branch and aconitase and isocitrate dehydrogenase in another branch. In the conditions of elevation of redox level, the TCA cycle is transformed into a non-cyclic open structure (hemicycle) leading to the export of the tricarboxylic acid (citrate) to the cytosol and to the accumulation of the dicarboxylic acids (malate and fumarate). While the buildup of NADPH in chloroplasts provides operation of the malate valve leading to establishment of NADH/NAD+ ratios in different cell compartments, the production of NADH by mitochondria drives citrate export by establishing conditions for the operation of the citrate valve. The latter regulates the intercompartmental NADPH/NADP+ ratio and contributes to the biosynthesis of amino acids and other metabolic products during photosynthesis.
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Affiliation(s)
- Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
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14
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Eprintsev AT, Fedorin DN. Purification of Constitutive Isoenzymes of Succinate Dehydrogenase from Zea mays Scutellum in the Homogeneous State and the Study of Their Characteristics. APPL BIOCHEM MICRO+ 2020. [DOI: 10.1134/s0003683820020064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Moysset L, Llambrich E, Simón E. Calcium changes in Robinia pseudoacacia pulvinar motor cells during nyctinastic closure mediated by phytochromes. PROTOPLASMA 2019; 256:615-629. [PMID: 30382423 DOI: 10.1007/s00709-018-1323-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/15/2018] [Indexed: 06/08/2023]
Abstract
Potassium pyroantimonate precipitation, transmission electron microscopy, and X-ray microanalysis were used to investigate the subcellular localization of loosely bound calcium in Robinia pseudoacacia pulvinar motor cells during phytochrome-mediated nyctinastic closure. Calcium localization was carried out in pulvini collected in white light 2 h after the beginning of the photoperiod, immediately after a red light or a far-red light pulse applied 2 h after the beginning of the photoperiod and after 15 or 25 min of darkness respectively. Calcium antimonate precipitates were found in all the pulvinar tissues from the epidermis to the vascular bundle, independent of the light treatment. At subcellular level, precipitates were found mainly in the intercellular spaces, the inner surface of the plasma membrane, cytoplasm, colloidal vacuoles, and nuclei. Red light enhanced the nyctinastic closure of leaflets and caused an asymmetric distribution of cytosolic calcium precipitates between the extensor and flexor motor cells. Both the number and area of the cytosolic calcium precipitates drastically increased in the extensor cells compared to the flexor motor cells. Red light had a rapid and transient effect on the distribution of cytosolic calcium precipitates, which occurred during or at the end of the irradiation, before leaflet closure. By contrast, the distribution of cytosolic loosely bound calcium was similar between the extensor and flexor motor cells after irradiation with far-red light. Our results demonstrate that red light causes specific calcium mobilization in pulvinar motor cells and suggest the involvement of cytoplasmic Ca2+ as a second messenger for phytochrome during nyctinastic closure.
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Affiliation(s)
- Luisa Moysset
- Departament of Evolutive Biology, Ecology and Environmental Sciences, Section of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, Margalef Building, Floor 5, 08028, Barcelona, Spain.
| | - Esther Llambrich
- Departament of Evolutive Biology, Ecology and Environmental Sciences, Section of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, Margalef Building, Floor 5, 08028, Barcelona, Spain
| | - Esther Simón
- Departament of Evolutive Biology, Ecology and Environmental Sciences, Section of Plant Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 643, Margalef Building, Floor 5, 08028, Barcelona, Spain
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16
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Eprintsev AT, Fedorin DN, Sazonova OV, Igamberdiev AU. Expression and properties of the mitochondrial and cytosolic forms of fumarase in sunflower cotyledons. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 129:305-309. [PMID: 29920456 DOI: 10.1016/j.plaphy.2018.06.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 06/08/2023]
Abstract
Fumarase (EC 4.2.1.2) is encoded in sunflower (Helianthus annuus L.) by two genes (FUM1 and FUM2) expressing correspondingly the mitochondrial and the cytosolic form. Both forms have been purified from sunflower cotyledons and characterized. Three quarters of fumarase activity is located in the mitochondrial and one quarter in the cytosolic fraction. The cytosolic form has lower pH optimum than the mitochondrial form, it possesses higher affinity to malate, activated by Mn2+ and less efficiently by Mg2+ while the mitochondrial form is activated only by Mg2+. It is proposed that the mitochondrial form is involved in the respiratory processes linked to the tricarboxylic acid cycle and the cytosolic form participates in the utilization of succinate produced in the glyoxylate cycle providing the flux to gluconeogenesis in germinating sunflower seeds.
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Affiliation(s)
- Alexander T Eprintsev
- Department of Biochemistry and Cell Physiology, Voronezh State University, Voronezh, 394006, Russia
| | - Dmitry N Fedorin
- Department of Biochemistry and Cell Physiology, Voronezh State University, Voronezh, 394006, Russia
| | - Oksana V Sazonova
- Department of Biochemistry and Cell Physiology, Voronezh State University, Voronezh, 394006, Russia
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
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17
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Igamberdiev AU, Bykova NV. Role of organic acids in the integration of cellular redox metabolism and mediation of redox signalling in photosynthetic tissues of higher plants. Free Radic Biol Med 2018; 122:74-85. [PMID: 29355740 DOI: 10.1016/j.freeradbiomed.2018.01.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/10/2018] [Accepted: 01/13/2018] [Indexed: 12/11/2022]
Abstract
Organic acids play a crucial role in numerous metabolic processes accompanied by transfer of electrons and protons and linked to the reduction/oxidation of major redox couples in plant cells, such as NAD, NADP, glutathione, and ascorbate. Fluxes through the pathways metabolizing organic acids modulate redox states in cell compartments, contribute to generation of reactive oxygen and nitrogen species, and mediate signal transduction processes. Organic acid metabolism not only functions to equilibrate the redox potential in plant cells but also to transfer redox equivalents between cell compartments supporting various metabolic processes. The most important role in this transfer belongs to different forms of malate dehydrogenase interconverting malate and oxaloacetate or forming pyruvate (malic enzymes). During photosynthesis malate serves as a major form of transfer of redox equivalents from chloroplasts to the cytosol and other compartments via the malate valve. On the other hand, mitochondria, via alterations of their redox potential, become a source of citrate that can be transported to the cytosol and support biosynthesis of amino acids. Citrate is also an important retrograde signalling compound that regulates transcription of several genes including those encoding the alternative oxidase. The alternative oxidase, which is activated by increased redox potential and by pyruvate, is, in turn, important for the maintenance of redox potential in mitochondria. The roles of organic acids in establishing redox equilibrium, supporting ionic gradients on membranes, acidification of the extracellular medium, and regulation of production of reactive oxygen and nitrogen species are discussed.
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Affiliation(s)
- Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, Canada A1B 3X9.
| | - Natalia V Bykova
- Morden Research and Development Centre, Agriculture and Agri-Food Canada, Morden, MB, Canada R6M 1Y5
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18
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Eprintsev AT, Fedorin DN, Cherkasskikh MV, Igamberdiev AU. Expression of succinate dehydrogenase and fumarase genes in maize leaves is mediated by cryptochrome. JOURNAL OF PLANT PHYSIOLOGY 2018; 221:81-84. [PMID: 29268085 DOI: 10.1016/j.jplph.2017.12.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 11/27/2017] [Accepted: 12/02/2017] [Indexed: 06/07/2023]
Abstract
Blue light inhibits succinate dehydrogenase and fumarase enzyme activity and gene expression in green leaves of maize (Zea mays L.). Irradiation of maize plants by blue light resulted in the transient decrease of transcripts of genes Sdh1-2 and Sdh2-3 encoding correspondingly the flavoprotein and iron-sulfur protein subunits of succinate dehydrogenase, and of Fum1 encoding the mitochondrial form of fumarase. The blue light effect was probably mediated by transcription factors COP1 and HY5, with the expression of the latter increased upon blue light treatment. This was accompanied by a decrease in the expression of COP1, presumably involved in proteasome degradation of HY5. It was also demonstrated that calcium ions do not participate in this process.
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Affiliation(s)
- Alexander T Eprintsev
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394006 Voronezh, Russia
| | - Dmitry N Fedorin
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394006 Voronezh, Russia
| | - Mikhail V Cherkasskikh
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394006 Voronezh, Russia
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland,St. John's, NL A1 B 3X9, Canada.
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Eprintsev AT, Fedorin DN, Dobychina MA, Igamberdiev AU. Expression and promoter methylation of succinate dehydrogenase and fumarase genes in maize under anoxic conditions. JOURNAL OF PLANT PHYSIOLOGY 2017; 216:197-201. [PMID: 28710913 DOI: 10.1016/j.jplph.2017.06.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 06/20/2017] [Accepted: 06/22/2017] [Indexed: 06/07/2023]
Abstract
Succinate dehydrogenase (SDH) and fumarase enzyme activity and expression of genes encoding the SDH subunits A (Sdh1-2), B (Sdh2-3), C (Sdh3), D (Sdh4) and the mitochondrial (Fum1) and cytosolic (Fum2) isoforms of fumarase were quantified in maize (Zea mays L.) seedlings exposed to atmospheres of air (control), N2, and CO2. The catalytic activity of SDH gradually declined in plants exposed to N2 atmospheres, with ∼40% activity remaining after 24h. In seedlings incubated in CO2, the suppression was even more pronounced. Fumarase activity was more stable, decreasing by one third after 24h of anoxia. The level of Sdh1-2 transcripts in seedlings declined significantly under N2 and even more rapidly upon exposure to CO2, with a concomitant increase in methylation of the corresponding promoters. The level of Sdh2-3 and Sdh3 transcripts also decreased under N2 and CO2, but the changes in promoter methylation were less pronounced, whereas the changes in the level of Sdh4 expression and promoter methylation were minor. Expression of Fum1 and Fum2 was affected by N2 and CO2 atmospheres, however without changes in corresponding promoter methylation. It is concluded that, under conditions of oxygen deficiency, succinate accumulates mainly due to downregulation of SDH gene expression and reduction of enzyme activity, and to a lesser extent due to the decrease of fumarase gene expression.
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Affiliation(s)
- Alexander T Eprintsev
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394006 Voronezh, Russia
| | - Dmitry N Fedorin
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394006 Voronezh, Russia
| | - Maria A Dobychina
- Department of Biochemistry and Cell Physiology, Voronezh State University, 394006 Voronezh, Russia
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL A1 B 3X9, Canada.
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Transcriptomic and proteomic analyses of leaves from Clematis terniflora DC. under high level of ultraviolet-B irradiation followed by dark treatment. J Proteomics 2017; 150:323-340. [DOI: 10.1016/j.jprot.2016.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 09/30/2016] [Accepted: 10/09/2016] [Indexed: 01/09/2023]
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21
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Lehmann MM, Wegener F, Barthel M, Maurino VG, Siegwolf RTW, Buchmann N, Werner C, Werner RA. Metabolic Fate of the Carboxyl Groups of Malate and Pyruvate and their Influence on δ(13)C of Leaf-Respired CO2 during Light Enhanced Dark Respiration. FRONTIERS IN PLANT SCIENCE 2016; 7:739. [PMID: 27375626 PMCID: PMC4891945 DOI: 10.3389/fpls.2016.00739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/13/2016] [Indexed: 05/03/2023]
Abstract
The enhanced CO2 release of illuminated leaves transferred into darkness, termed "light enhanced dark respiration (LEDR)", is often associated with an increase in the carbon isotope ratio of the respired CO2 (δ(13)CLEDR). The latter has been hypothesized to result from different respiratory substrates and decarboxylation reactions in various metabolic pathways, which are poorly understood so far. To provide a better insight into the underlying metabolic processes of δ(13)CLEDR, we fed position-specific (13)C-labeled malate and pyruvate via the xylem stream to leaves of species with high and low δ(13)CLEDR values (Halimium halimifolium and Oxalis triangularis, respectively). During respective label application, we determined label-derived leaf (13)CO2 respiration using laser spectroscopy and the (13)C allocation to metabolic fractions during light-dark transitions. Our results clearly show that both carboxyl groups (C-1 and C-4 position) of malate similarly influence respiration and metabolic fractions in both species, indicating possible isotope randomization of the carboxyl groups of malate by the fumarase reaction. While C-2 position of pyruvate was only weakly respired, the species-specific difference in natural δ(13)CLEDR patterns were best reflected by the (13)CO2 respiration patterns of the C-1 position of pyruvate. Furthermore, (13)C label from malate and pyruvate were mainly allocated to amino and organic acid fractions in both species and only little to sugar and lipid fractions. In summary, our results suggest that respiration of both carboxyl groups of malate (via fumarase) by tricarboxylic acid cycle reactions or by NAD-malic enzyme influences δ(13)CLEDR. The latter supplies the pyruvate dehydrogenase reaction, which in turn determines natural δ(13)CLEDR pattern by releasing the C-1 position of pyruvate.
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Affiliation(s)
- Marco M. Lehmann
- Laboratory of Atmospheric Chemistry, Paul Scherrer InstituteVilligen, Switzerland
- Institute of Agricultural Sciences, ETH ZurichZurich, Switzerland
| | | | - Matti Barthel
- Institute of Agricultural Sciences, ETH ZurichZurich, Switzerland
| | - Veronica G. Maurino
- Plant Molecular Physiology and Biotechnology Group, Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University and Cluster of Excellence on Plant Sciences (CEPLAS)Düsseldorf, Germany
| | - Rolf T. W. Siegwolf
- Laboratory of Atmospheric Chemistry, Paul Scherrer InstituteVilligen, Switzerland
| | - Nina Buchmann
- Institute of Agricultural Sciences, ETH ZurichZurich, Switzerland
| | | | - Roland A. Werner
- Institute of Agricultural Sciences, ETH ZurichZurich, Switzerland
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Igamberdiev AU, Eprintsev AT. Organic Acids: The Pools of Fixed Carbon Involved in Redox Regulation and Energy Balance in Higher Plants. FRONTIERS IN PLANT SCIENCE 2016; 7:1042. [PMID: 27471516 PMCID: PMC4945632 DOI: 10.3389/fpls.2016.01042] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/04/2016] [Indexed: 05/18/2023]
Abstract
Organic acids are synthesized in plants as a result of the incomplete oxidation of photosynthetic products and represent the stored pools of fixed carbon accumulated due to different transient times of conversion of carbon compounds in metabolic pathways. When redox level in the cell increases, e.g., in conditions of active photosynthesis, the tricarboxylic acid (TCA) cycle in mitochondria is transformed to a partial cycle supplying citrate for the synthesis of 2-oxoglutarate and glutamate (citrate valve), while malate is accumulated and participates in the redox balance in different cell compartments (via malate valve). This results in malate and citrate frequently being the most accumulated acids in plants. However, the intensity of reactions linked to the conversion of these compounds can cause preferential accumulation of other organic acids, e.g., fumarate or isocitrate, in higher concentrations than malate and citrate. The secondary reactions, associated with the central metabolic pathways, in particularly with the TCA cycle, result in accumulation of other organic acids that are derived from the intermediates of the cycle. They form the additional pools of fixed carbon and stabilize the TCA cycle. Trans-aconitate is formed from citrate or cis-aconitate, accumulation of hydroxycitrate can be linked to metabolism of 2-oxoglutarate, while 4-hydroxy-2-oxoglutarate can be formed from pyruvate and glyoxylate. Glyoxylate, a product of either glycolate oxidase or isocitrate lyase, can be converted to oxalate. Malonate is accumulated at high concentrations in legume plants. Organic acids play a role in plants in providing redox equilibrium, supporting ionic gradients on membranes, and acidification of the extracellular medium.
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Affiliation(s)
- Abir U. Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John’sNL, Canada
- *Correspondence: Abir U. Igamberdiev,
| | - Alexander T. Eprintsev
- Department of Biochemistry and Cell Physiology, Voronezh State UniversityVoronezh, Russia
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