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Chaux F, Jarrige D, Rodrigues-Azevedo M, Bujaldon S, Caspari OD, Ozawa SI, Drapier D, Vallon O, Choquet Y, de Vitry C. Chloroplast ATP synthase biogenesis requires peripheral stalk subunits AtpF and ATPG and stabilization of atpE mRNA by OPR protein MDE1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:1582-1599. [PMID: 37824282 DOI: 10.1111/tpj.16448] [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: 05/17/2023] [Revised: 08/15/2023] [Accepted: 08/21/2023] [Indexed: 10/14/2023]
Abstract
Chloroplast ATP synthase contains subunits of plastid and nuclear genetic origin. To investigate the coordinated biogenesis of this complex, we isolated novel ATP synthase mutants in the green alga Chlamydomonas reinhardtii by screening for high light sensitivity. We report here the characterization of mutants affecting the two peripheral stalk subunits b and b', encoded respectively by the atpF and ATPG genes, and of three independent mutants which identify the nuclear factor MDE1, required to stabilize the chloroplast-encoded atpE mRNA. Whole-genome sequencing revealed a transposon insertion in the 3'UTR of ATPG while mass spectrometry shows a small accumulation of functional ATP synthase in this knock-down ATPG mutant. In contrast, knock-out ATPG mutants, obtained by CRISPR-Cas9 gene editing, fully prevent ATP synthase function and accumulation, as also observed in an atpF frame-shift mutant. Crossing ATP synthase mutants with the ftsh1-1 mutant of the major thylakoid protease identifies AtpH as an FTSH substrate, and shows that FTSH significantly contributes to the concerted accumulation of ATP synthase subunits. In mde1 mutants, the absence of atpE transcript fully prevents ATP synthase biogenesis and photosynthesis. Using chimeric atpE genes to rescue atpE transcript accumulation, we demonstrate that MDE1, a novel octotricopeptide repeat (OPR) protein, genetically targets the atpE 5'UTR. In the perspective of the primary endosymbiosis (~1.5 Gy), the recruitment of MDE1 to its atpE target exemplifies a nucleus/chloroplast interplay that evolved rather recently, in the ancestor of the CS clade of Chlorophyceae, ~300 My ago.
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Affiliation(s)
- Frédéric Chaux
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Domitille Jarrige
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Marcio Rodrigues-Azevedo
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Sandrine Bujaldon
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Oliver D Caspari
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Shin-Ichiro Ozawa
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Dominique Drapier
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Olivier Vallon
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Yves Choquet
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
| | - Catherine de Vitry
- Unité Mixte de Recherche (UMR) 7141, Centre National de la Recherche Scientifique (CNRS) and Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, F-75005, Paris, France
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Pang X, Nawrocki WJ, Cardol P, Zheng M, Jiang J, Fang Y, Yang W, Croce R, Tian L. Weak acids produced during anaerobic respiration suppress both photosynthesis and aerobic respiration. Nat Commun 2023; 14:4207. [PMID: 37452043 PMCID: PMC10349137 DOI: 10.1038/s41467-023-39898-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 07/02/2023] [Indexed: 07/18/2023] Open
Abstract
While photosynthesis transforms sunlight energy into sugar, aerobic and anaerobic respiration (fermentation) catabolizes sugars to fuel cellular activities. These processes take place within one cell across several compartments, however it remains largely unexplored how they interact with one another. Here we report that the weak acids produced during fermentation down-regulate both photosynthesis and aerobic respiration. This effect is mechanistically explained with an "ion trapping" model, in which the lipid bilayer selectively traps protons that effectively acidify subcellular compartments with smaller buffer capacities - such as the thylakoid lumen. Physiologically, we propose that under certain conditions, e.g., dim light at dawn, tuning down the photosynthetic light reaction could mitigate the pressure on its electron transport chains, while suppression of respiration could accelerate the net oxygen evolution, thus speeding up the recovery from hypoxia. Since we show that this effect is conserved across photosynthetic phyla, these results indicate that fermentation metabolites exert widespread feedback control over photosynthesis and aerobic respiration. This likely allows algae to better cope with changing environmental conditions.
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Affiliation(s)
- Xiaojie Pang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Wojciech J Nawrocki
- Department of Physics and Astronomy and LaserLab Amsterdam Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, UMR7141, Centre National de la Recherche Scientifique, Sorbonne Université, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005, Paris, France
| | - Pierre Cardol
- Génétique et Physiologie des Microalgues, InBioS/Phytosystems, Institut de Botanique, Université de Liège, B22, 4000, Liège, Belgium
| | - Mengyuan Zheng
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jingjing Jiang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
| | - Yuan Fang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Wenqiang Yang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Roberta Croce
- Department of Physics and Astronomy and LaserLab Amsterdam Faculty of Science, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Lijin Tian
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093, Beijing, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
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Choi HI, Hwang SW, Kim J, Park B, Jin E, Choi IG, Sim SJ. Augmented CO 2 tolerance by expressing a single H +-pump enables microalgal valorization of industrial flue gas. Nat Commun 2021; 12:6049. [PMID: 34663809 PMCID: PMC8523702 DOI: 10.1038/s41467-021-26325-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 10/01/2021] [Indexed: 12/02/2022] Open
Abstract
Microalgae can accumulate various carbon-neutral products, but their real-world applications are hindered by their CO2 susceptibility. Herein, the transcriptomic changes in a model microalga, Chlamydomonas reinhardtii, in a high-CO2 milieu (20%) are evaluated. The primary toxicity mechanism consists of aberrantly low expression of plasma membrane H+-ATPases (PMAs) accompanied by intracellular acidification. Our results demonstrate that the expression of a universally expressible PMA in wild-type strains makes them capable of not only thriving in acidity levels that they usually cannot survive but also exhibiting 3.2-fold increased photoautotrophic production against high CO2 via maintenance of a higher cytoplasmic pH. A proof-of-concept experiment involving cultivation with toxic flue gas (13 vol% CO2, 20 ppm NOX, and 32 ppm SOX) shows that the production of CO2-based bioproducts by the strain is doubled compared with that by the wild-type, implying that this strategy potentially enables the microalgal valorization of CO2 in industrial exhaust.
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Affiliation(s)
- Hong Il Choi
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Sung-Won Hwang
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Jongrae Kim
- Department of Life Science, Hanyang University, 206, Wangsimni-ro, Seongbuk-gu, Seoul, 04763, Republic of Korea
| | - Byeonghyeok Park
- Department of Biotechnology, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - EonSeon Jin
- Department of Life Science, Hanyang University, 206, Wangsimni-ro, Seongbuk-gu, Seoul, 04763, Republic of Korea
| | - In-Geol Choi
- Department of Biotechnology, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Sang Jun Sim
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
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Chadee A, Alber NA, Dahal K, Vanlerberghe GC. The Complementary Roles of Chloroplast Cyclic Electron Transport and Mitochondrial Alternative Oxidase to Ensure Photosynthetic Performance. FRONTIERS IN PLANT SCIENCE 2021; 12:748204. [PMID: 34650584 PMCID: PMC8505746 DOI: 10.3389/fpls.2021.748204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 08/30/2021] [Indexed: 05/29/2023]
Abstract
Chloroplasts use light energy and a linear electron transport (LET) pathway for the coupled generation of NADPH and ATP. It is widely accepted that the production ratio of ATP to NADPH is usually less than required to fulfill the energetic needs of the chloroplast. Left uncorrected, this would quickly result in an over-reduction of the stromal pyridine nucleotide pool (i.e., high NADPH/NADP+ ratio) and under-energization of the stromal adenine nucleotide pool (i.e., low ATP/ADP ratio). These imbalances could cause metabolic bottlenecks, as well as increased generation of damaging reactive oxygen species. Chloroplast cyclic electron transport (CET) and the chloroplast malate valve could each act to prevent stromal over-reduction, albeit in distinct ways. CET avoids the NADPH production associated with LET, while the malate valve consumes the NADPH associated with LET. CET could operate by one of two different pathways, depending upon the chloroplast ATP demand. The NADH dehydrogenase-like pathway yields a higher ATP return per electron flux than the pathway involving PROTON GRADIENT REGULATION5 (PGR5) and PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE1 (PGRL1). Similarly, the malate valve could couple with one of two different mitochondrial electron transport pathways, depending upon the cytosolic ATP demand. The cytochrome pathway yields a higher ATP return per electron flux than the alternative oxidase (AOX) pathway. In both Arabidopsis thaliana and Chlamydomonas reinhardtii, PGR5/PGRL1 pathway mutants have increased amounts of AOX, suggesting complementary roles for these two lesser-ATP yielding mechanisms of preventing stromal over-reduction. These two pathways may become most relevant under environmental stress conditions that lower the ATP demands for carbon fixation and carbohydrate export.
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Affiliation(s)
- Avesh Chadee
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Nicole A. Alber
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Keshav Dahal
- Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, NB, Canada
| | - Greg C. Vanlerberghe
- Department of Biological Sciences, and Department of Cell and Systems Biology, University of Toronto Scarborough, Toronto, ON, Canada
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5
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Alber NA, Vanlerberghe GC. The flexibility of metabolic interactions between chloroplasts and mitochondria in Nicotiana tabacum leaf. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1625-1646. [PMID: 33811402 DOI: 10.1111/tpj.15259] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 05/02/2023]
Abstract
To examine the effect of mitochondrial function on photosynthesis, wild-type and transgenic Nicotiana tabacum with varying amounts of alternative oxidase (AOX) were treated with different respiratory inhibitors. Initially, each inhibitor increased the reduction state of the chloroplast electron transport chain, most severely in AOX knockdowns and least severely in AOX overexpressors. This indicated that the mitochondrion was a necessary sink for photo-generated reductant, contributing to the 'P700 oxidation capacity' of photosystem I. Initially, the Complex III inhibitor myxothiazol and the mitochondrial ATP synthase inhibitor oligomycin caused an increase in photosystem II regulated non-photochemical quenching not evident with the Complex III inhibitor antimycin A (AA). This indicated that the increased quenching depended upon AA-sensitive cyclic electron transport (CET). Following 12 h with oligomycin, the reduction state of the chloroplast electron transport chain recovered in all plant lines. Recovery was associated with large increases in the protein amount of chloroplast ATP synthase and mitochondrial uncoupling protein. This increased the capacity for photophosphorylation in the absence of oxidative phosphorylation and enabled the mitochondrion to act again as a sink for photo-generated reductant. Comparing the AA and myxothiazol treatments at 12 h showed that CET optimized photosystem I quantum yield, depending upon the P700 oxidation capacity. When this capacity was too high, CET drew electrons away from other sinks, moderating the P700+ amount. When P700 oxidation capacity was too low, CET acted as an electron overflow, moderating the amount of reduced P700. This study reveals flexible chloroplast-mitochondrion interactions able to overcome lesions in energy metabolism.
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Affiliation(s)
- Nicole A Alber
- Department of Biological Sciences, Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C1A4, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences, Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C1A4, Canada
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6
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Bo DD, Magneschi L, Bedhomme M, Billey E, Deragon E, Storti M, Menneteau M, Richard C, Rak C, Lapeyre M, Lembrouk M, Conte M, Gros V, Tourcier G, Giustini C, Falconet D, Curien G, Allorent G, Petroutsos D, Laeuffer F, Fourage L, Jouhet J, Maréchal E, Finazzi G, Collin S. Consequences of Mixotrophy on Cell Energetic Metabolism in Microchloropsis gaditana Revealed by Genetic Engineering and Metabolic Approaches. FRONTIERS IN PLANT SCIENCE 2021; 12:628684. [PMID: 34113360 PMCID: PMC8185151 DOI: 10.3389/fpls.2021.628684] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Algae belonging to the Microchloropsis genus are promising organisms for biotech purposes, being able to accumulate large amounts of lipid reserves. These organisms adapt to different trophic conditions, thriving in strict photoautotrophic conditions, as well as in the concomitant presence of light plus reduced external carbon as energy sources (mixotrophy). In this work, we investigated the mixotrophic responses of Microchloropsis gaditana (formerly Nannochloropsis gaditana). Using the Biolog growth test, in which cells are loaded into multiwell plates coated with different organic compounds, we could not find a suitable substrate for Microchloropsis mixotrophy. By contrast, addition of the Lysogeny broth (LB) to the inorganic growth medium had a benefit on growth, enhancing respiratory activity at the expense of photosynthetic performances. To further dissect the role of respiration in Microchloropsis mixotrophy, we focused on the mitochondrial alternative oxidase (AOX), a protein involved in energy management in other algae prospering in mixotrophy. Knocking-out the AOX1 gene by transcription activator-like effector nuclease (TALE-N) led to the loss of capacity to implement growth upon addition of LB supporting the hypothesis that the effect of this medium was related to a provision of reduced carbon. We conclude that mixotrophic growth in Microchloropsis is dominated by respiratory rather than by photosynthetic energetic metabolism and discuss the possible reasons for this behavior in relationship with fatty acid breakdown via β-oxidation in this oleaginous alga.
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Affiliation(s)
- Davide Dal Bo
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Leonardo Magneschi
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Mariette Bedhomme
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Elodie Billey
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
- Total Refining Chemicals, Tour Coupole, Paris La Défense, France
| | - Etienne Deragon
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Mattia Storti
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Mathilde Menneteau
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Christelle Richard
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Camille Rak
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Morgane Lapeyre
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Mehdi Lembrouk
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Melissa Conte
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Valérie Gros
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Guillaume Tourcier
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Cécile Giustini
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Denis Falconet
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Gilles Curien
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Guillaume Allorent
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Dimitris Petroutsos
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | | | - Laurent Fourage
- Total Refining Chemicals, Tour Coupole, Paris La Défense, France
| | - Juliette Jouhet
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Eric Maréchal
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Giovanni Finazzi
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Séverine Collin
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
- Total Refining Chemicals, Tour Coupole, Paris La Défense, France
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7
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Buchert F, Bailleul B, Joliot P. Disentangling chloroplast ATP synthase regulation by proton motive force and thiol modulation in Arabidopsis leaves. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148434. [PMID: 33932368 DOI: 10.1016/j.bbabio.2021.148434] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 04/06/2021] [Accepted: 04/20/2021] [Indexed: 11/29/2022]
Abstract
The chloroplast ATP synthase (CF1Fo) contains a specific feature to the green lineage: a γ-subunit redox domain that contains a cysteine couple which interacts with the torque-transmitting βDELSEED-loop. This thiol modulation equips CF1Fo with an important environmental fine-tuning mechanism. In vitro, disulfide formation in the γ-redox domain slows down the activity of the CF1Fo at low transmembrane electrochemical proton gradient ( [Formula: see text] ), which agrees with its proposed role as chock based on recently solved structure. The γ-dithiol formation at the onset of light is crucial to maximize photosynthetic efficiency since it lowers the [Formula: see text] activation level for ATP synthesis in vitro. Here, we validate these findings in vivo by utilizing absorption spectroscopy in Arabidopsis thaliana. To do so, we monitored the [Formula: see text] present in darkness and identified its mitochondrial sources. By following the fate and components of light-induced extra [Formula: see text] , we estimated the ATP lifetime that lasted up to tens of minutes after long illuminations. Based on the relationship between [Formula: see text] and CF1Fo activity, we conclude that the dithiol configuration in vivo facilitates photosynthesis by driving the same ATP synthesis rate at a significative lower [Formula: see text] than in the γ-disulfide state. The presented in vivo findings are an additional proof of the importance of CF1Fo thiol modulation, reconciling biochemical in vitro studies and structural insights.
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Affiliation(s)
- Felix Buchert
- Laboratory of Chloroplast Biology and Light-Sensing in Microalgae - UMR7141, IBPC, CNRS-Sorbonne Université, Paris, France; Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany.
| | - Benjamin Bailleul
- Laboratory of Chloroplast Biology and Light-Sensing in Microalgae - UMR7141, IBPC, CNRS-Sorbonne Université, Paris, France
| | - Pierre Joliot
- Laboratory of Chloroplast Biology and Light-Sensing in Microalgae - UMR7141, IBPC, CNRS-Sorbonne Université, Paris, France
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8
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Falciatore A, Jaubert M, Bouly JP, Bailleul B, Mock T. Diatom Molecular Research Comes of Age: Model Species for Studying Phytoplankton Biology and Diversity. THE PLANT CELL 2020; 32:547-572. [PMID: 31852772 PMCID: PMC7054031 DOI: 10.1105/tpc.19.00158] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 10/18/2019] [Accepted: 12/13/2019] [Indexed: 05/08/2023]
Abstract
Diatoms are the world's most diverse group of algae, comprising at least 100,000 species. Contributing ∼20% of annual global carbon fixation, they underpin major aquatic food webs and drive global biogeochemical cycles. Over the past two decades, Thalassiosira pseudonana and Phaeodactylum tricornutum have become the most important model systems for diatom molecular research, ranging from cell biology to ecophysiology, due to their rapid growth rates, small genomes, and the cumulative wealth of associated genetic resources. To explore the evolutionary divergence of diatoms, additional model species are emerging, such as Fragilariopsis cylindrus and Pseudo-nitzschia multistriata Here, we describe how functional genomics and reverse genetics have contributed to our understanding of this important class of microalgae in the context of evolution, cell biology, and metabolic adaptations. Our review will also highlight promising areas of investigation into the diversity of these photosynthetic organisms, including the discovery of new molecular pathways governing the life of secondary plastid-bearing organisms in aquatic environments.
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Affiliation(s)
- Angela Falciatore
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Marianne Jaubert
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Jean-Pierre Bouly
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Benjamin Bailleul
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
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9
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Burlacot A, Peltier G, Li-Beisson Y. Subcellular Energetics and Carbon Storage in Chlamydomonas. Cells 2019; 8:E1154. [PMID: 31561610 PMCID: PMC6830334 DOI: 10.3390/cells8101154] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 01/09/2023] Open
Abstract
Microalgae have emerged as a promising platform for production of carbon- and energy- rich molecules, notably starch and oil. Establishing an economically viable algal biotechnology sector requires a holistic understanding of algal photosynthesis, physiology, cell cycle and metabolism. Starch/oil productivity is a combined effect of their cellular content and cell division activities. Cell growth, starch and fatty acid synthesis all require carbon building blocks and a source of energy in the form of ATP and NADPH, but with a different requirement in ATP/NADPH ratio. Thus, several cellular mechanisms have been developed by microalgae to balance ATP and NADPH supply which are essentially produced by photosynthesis. Major energy management mechanisms include ATP production by the chloroplast-based cyclic electron flow and NADPH removal by water-water cycles. Furthermore, energetic coupling between chloroplast and other cellular compartments, mitochondria and peroxisome, is increasingly recognized as an important process involved in the chloroplast redox poise. Emerging literature suggests that alterations of energy management pathways affect not only cell fitness and survival, but also influence biomass content and composition. These emerging discoveries are important steps towards diverting algal photosynthetic energy to useful products for biotechnological applications.
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Affiliation(s)
- Adrien Burlacot
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache CEDEX, 13108 Saint Paul-Lez-Durance, France.
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache CEDEX, 13108 Saint Paul-Lez-Durance, France.
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache CEDEX, 13108 Saint Paul-Lez-Durance, France.
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10
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Majeran W, Wostrikoff K, Wollman FA, Vallon O. Role of ClpP in the Biogenesis and Degradation of RuBisCO and ATP Synthase in Chlamydomonas reinhardtii. PLANTS (BASEL, SWITZERLAND) 2019; 8:E191. [PMID: 31248038 PMCID: PMC6681370 DOI: 10.3390/plants8070191] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 01/17/2023]
Abstract
Ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) associates a chloroplast- and a nucleus-encoded subunit (LSU and SSU). It constitutes the major entry point of inorganic carbon into the biosphere as it catalyzes photosynthetic CO2 fixation. Its abundance and richness in sulfur-containing amino acids make it a prime source of N and S during nutrient starvation, when photosynthesis is downregulated and a high RuBisCO level is no longer needed. Here we show that translational attenuation of ClpP1 in the green alga Chlamydomonas reinhardtii results in retarded degradation of RuBisCO during S- and N-starvation, suggesting that the Clp protease is a major effector of RubisCO degradation in these conditions. Furthermore, we show that ClpP cannot be attenuated in the context of rbcL point mutations that prevent LSU folding. The mutant LSU remains in interaction with the chloroplast chaperonin complex. We propose that degradation of the mutant LSU by the Clp protease is necessary to prevent poisoning of the chaperonin. In the total absence of LSU, attenuation of ClpP leads to a dramatic stabilization of unassembled SSU, indicating that Clp is responsible for its degradation. In contrast, attenuation of ClpP in the absence of SSU does not lead to overaccumulation of LSU, whose translation is controlled by assembly. Altogether, these results point to RuBisCO degradation as one of the major house-keeping functions of the essential Clp protease. In addition, we show that non-assembled subunits of the ATP synthase are also stabilized when ClpP is attenuated. In the case of the atpA-FUD16 mutation, this can even allow the assembly of a small amount of CF1, which partially restores phototrophy.
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Affiliation(s)
- Wojciech Majeran
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, Université Paris-Diderot, Université Paris-Sud, INRA, Université Evry, Université Paris-Saclay, Rue de Noetzlin, 91190 Gif-sur-Yvette, France.
| | - Katia Wostrikoff
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Francis-André Wollman
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Olivier Vallon
- UMR7141 CNRS/Sorbonne Université, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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11
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Brzezowski P, Ksas B, Havaux M, Grimm B, Chazaux M, Peltier G, Johnson X, Alric J. The function of PROTOPORPHYRINOGEN IX OXIDASE in chlorophyll biosynthesis requires oxidised plastoquinone in Chlamydomonas reinhardtii. Commun Biol 2019; 2:159. [PMID: 31069268 PMCID: PMC6499784 DOI: 10.1038/s42003-019-0395-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 03/20/2019] [Indexed: 12/23/2022] Open
Abstract
In the last common enzymatic step of tetrapyrrole biosynthesis, prior to the branching point leading to the biosynthesis of heme and chlorophyll, protoporphyrinogen IX (Protogen) is oxidised to protoporphyrin IX (Proto) by protoporphyrinogen IX oxidase (PPX). The absence of thylakoid-localised plastid terminal oxidase 2 (PTOX2) and cytochrome b6f complex in the ptox2 petB mutant, results in almost complete reduction of the plastoquinone pool (PQ pool) in light. Here we show that the lack of oxidised PQ impairs PPX function, leading to accumulation and subsequently uncontrolled oxidation of Protogen to non-metabolised Proto. Addition of 3(3,4-Dichlorophenyl)-1,1-dimethylurea (DCMU) prevents the over-reduction of the PQ pool in ptox2 petB and decreases Proto accumulation. This observation strongly indicates the need of oxidised PQ as the electron acceptor for the PPX reaction in Chlamydomonas reinhardtii. The PPX-PQ pool interaction is proposed to function as a feedback loop between photosynthetic electron transport and chlorophyll biosynthesis.
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Affiliation(s)
- Pawel Brzezowski
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- Humboldt-Universität zu Berlin, Institut für Biologie/Pflanzenphysiologie, 10115 Berlin, Germany
| | - Brigitte Ksas
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire d’Ecophysiologie Moléculaire des Plantes, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Michel Havaux
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire d’Ecophysiologie Moléculaire des Plantes, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Bernhard Grimm
- Humboldt-Universität zu Berlin, Institut für Biologie/Pflanzenphysiologie, 10115 Berlin, Germany
| | - Marie Chazaux
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Jean Alric
- Aix Marseille Université, CNRS, CEA, Institut de Biosciences et Biotechnologies Aix-Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
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12
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Liang Y, Kong F, Torres-Romero I, Burlacot A, Cuine S, Légeret B, Billon E, Brotman Y, Alseekh S, Fernie AR, Beisson F, Peltier G, Li-Beisson Y. Branched-Chain Amino Acid Catabolism Impacts Triacylglycerol Homeostasis in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2019; 179:1502-1514. [PMID: 30728273 PMCID: PMC6446750 DOI: 10.1104/pp.18.01584] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/30/2019] [Indexed: 05/05/2023]
Abstract
Nitrogen (N) starvation-induced triacylglycerol (TAG) synthesis, and its complex relationship with starch metabolism in algal cells, has been intensively studied; however, few studies have examined the interaction between amino acid metabolism and TAG biosynthesis. Here, via a forward genetic screen for TAG homeostasis, we isolated a Chlamydomonas (Chlamydomonas reinhardtii) mutant (bkdE1α) that is deficient in the E1α subunit of the branched-chain ketoacid dehydrogenase (BCKDH) complex. Metabolomics analysis revealed a defect in the catabolism of branched-chain amino acids in bkdE1α Furthermore, this mutant accumulated 30% less TAG than the parental strain during N starvation and was compromised in TAG remobilization upon N resupply. Intriguingly, the rate of mitochondrial respiration was 20% to 35% lower in bkdE1α compared with the parental strains. Three additional knockout mutants of the other components of the BCKDH complex exhibited phenotypes similar to that of bkdE1α Transcriptional responses of BCKDH to different N status were consistent with its role in TAG homeostasis. Collectively, these results indicate that branched-chain amino acid catabolism contributes to TAG metabolism by providing carbon precursors and ATP, thus highlighting the complex interplay between distinct subcellular metabolisms for oil storage in green microalgae.
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Affiliation(s)
- Yuanxue Liang
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Fantao Kong
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Ismael Torres-Romero
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Adrien Burlacot
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Stéphan Cuine
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Bertrand Légeret
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Emmanuelle Billon
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Yariv Brotman
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Saleh Alseekh
- 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
| | - Fred Beisson
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Gilles Peltier
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Yonghua Li-Beisson
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
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13
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Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. The lipid biochemistry of eukaryotic algae. Prog Lipid Res 2019; 74:31-68. [PMID: 30703388 DOI: 10.1016/j.plipres.2019.01.003] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/06/2023]
Abstract
Algal lipid metabolism fascinates both scientists and entrepreneurs due to the large diversity of fatty acyl structures that algae produce. Algae have therefore long been studied as sources of genes for novel fatty acids; and, due to their superior biomass productivity, algae are also considered a potential feedstock for biofuels. However, a major issue in a commercially viable "algal oil-to-biofuel" industry is the high production cost, because most algal species only produce large amounts of oils after being exposed to stress conditions. Recent studies have therefore focused on the identification of factors involved in TAG metabolism, on the subcellular organization of lipid pathways, and on interactions between organelles. This has been accompanied by the development of genetic/genomic and synthetic biological tools not only for the reference green alga Chlamydomonas reinhardtii but also for Nannochloropsis spp. and Phaeodactylum tricornutum. Advances in our understanding of enzymes and regulatory proteins of acyl lipid biosynthesis and turnover are described herein with a focus on carbon and energetic aspects. We also summarize how changes in environmental factors can impact lipid metabolism and describe present and potential industrial uses of algal lipids.
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Affiliation(s)
- Yonghua Li-Beisson
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F-13108, France.
| | - Jay J Thelen
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - Eric Fedosejevs
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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14
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Kaye Y, Huang W, Clowez S, Saroussi S, Idoine A, Sanz-Luque E, Grossman AR. The mitochondrial alternative oxidase from Chlamydomonas reinhardtii enables survival in high light. J Biol Chem 2018; 294:1380-1395. [PMID: 30510139 DOI: 10.1074/jbc.ra118.004667] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/24/2018] [Indexed: 01/07/2023] Open
Abstract
Photosynthetic organisms often experience extreme light conditions that can cause hyper-reduction of the chloroplast electron transport chain, resulting in oxidative damage. Accumulating evidence suggests that mitochondrial respiration and chloroplast photosynthesis are coupled when cells are absorbing high levels of excitation energy. This coupling helps protect the cells from hyper-reduction of photosynthetic electron carriers and diminishes the production of reactive oxygen species (ROS). To examine this cooperative protection, here we characterized Chlamydomonas reinhardtii mutants lacking the mitochondrial alternative terminal respiratory oxidases, CrAOX1 and CrAOX2. Using fluorescent fusion proteins, we experimentally demonstrated that both enzymes localize to mitochondria. We also observed that the mutant strains were more sensitive than WT cells to high light under mixotrophic and photoautotrophic conditions, with the aox1 strain being more sensitive than aox2 Additionally, the lack of CrAOX1 increased ROS accumulation, especially in very high light, and damaged the photosynthetic machinery, ultimately resulting in cell death. These findings indicate that the Chlamydomonas AOX proteins can participate in acclimation of C. reinhardtii cells to excess absorbed light energy. They suggest that when photosynthetic electron carriers are highly reduced, a chloroplast-mitochondria coupling allows safe dissipation of photosynthetically derived electrons via the reduction of O2 through AOX (especially AOX1)-dependent mitochondrial respiration.
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Affiliation(s)
- Yuval Kaye
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305.
| | - Weichao Huang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Sophie Clowez
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Shai Saroussi
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Adam Idoine
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Emanuel Sanz-Luque
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
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15
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Curien G, Flori S, Villanova V, Magneschi L, Giustini C, Forti G, Matringe M, Petroutsos D, Kuntz M, Finazzi G. The Water to Water Cycles in Microalgae. PLANT & CELL PHYSIOLOGY 2016; 57:1354-1363. [PMID: 26955846 DOI: 10.1093/pcp/pcw048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 02/23/2016] [Indexed: 05/28/2023]
Abstract
In oxygenic photosynthesis, light produces ATP plus NADPH via linear electron transfer, i.e. the in-series activity of the two photosystems: PSI and PSII. This process, however, is thought not to be sufficient to provide enough ATP per NADPH for carbon assimilation in the Calvin-Benson-Bassham cycle. Thus, it is assumed that additional ATP can be generated by alternative electron pathways. These circuits produce an electrochemical proton gradient without NADPH synthesis, and, although they often represent a small proportion of the linear electron flow, they could have a huge importance in optimizing CO2 assimilation. In Viridiplantae, there is a consensus that alternative electron flow comprises cyclic electron flow around PSI and the water to water cycles. The latter processes include photosynthetic O2 reduction via the Mehler reaction at PSI, the plastoquinone terminal oxidase downstream of PSII, photorespiration (the oxygenase activity of Rubisco) and the export of reducing equivalents towards the mitochondrial oxidases, through the malate shuttle. In this review, we summarize current knowledge about the role of the water to water cycles in photosynthesis, with a special focus on their occurrence and physiological roles in microalgae.
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Affiliation(s)
- Gilles Curien
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Serena Flori
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | | | - Leonardo Magneschi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Cécile Giustini
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Giorgio Forti
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Michel Matringe
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Dimitris Petroutsos
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Marcel Kuntz
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
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16
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Energetic coupling between plastids and mitochondria drives CO2 assimilation in diatoms. Nature 2015; 524:366-9. [PMID: 26168400 DOI: 10.1038/nature14599] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/28/2015] [Indexed: 01/04/2023]
Abstract
Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by absorbing carbon dioxide from the atmosphere, sequestering it via the biological carbon pump and ultimately burying organic carbon in the lithosphere. The proportion of planetary primary production by diatoms in the modern oceans is roughly equivalent to that of terrestrial rainforests. In photosynthesis, the efficient conversion of carbon dioxide into organic matter requires a tight control of the ATP/NADPH ratio which, in other photosynthetic organisms, relies principally on a range of plastid-localized ATP generating processes. Here we show that diatoms regulate ATP/NADPH through extensive energetic exchanges between plastids and mitochondria. This interaction comprises the re-routing of reducing power generated in the plastid towards mitochondria and the import of mitochondrial ATP into the plastid, and is mandatory for optimized carbon fixation and growth. We propose that the process may have contributed to the ecological success of diatoms in the ocean.
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Erickson E, Wakao S, Niyogi KK. Light stress and photoprotection in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:449-465. [PMID: 25758978 DOI: 10.1111/tpj.12825] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 03/05/2015] [Accepted: 03/06/2015] [Indexed: 05/18/2023]
Abstract
Plants and algae require light for photosynthesis, but absorption of too much light can lead to photo-oxidative damage to the photosynthetic apparatus and sustained decreases in the efficiency and rate of photosynthesis (photoinhibition). Light stress can adversely affect growth and viability, necessitating that photosynthetic organisms acclimate to different environmental conditions in order to alleviate the detrimental effects of excess light. The model unicellular green alga, Chlamydomonas reinhardtii, employs diverse strategies of regulation and photoprotection to avoid, minimize, and repair photo-oxidative damage in stressful light conditions, allowing for acclimation to different and changing environments.
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Affiliation(s)
- Erika Erickson
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Setsuko Wakao
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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Steinbeck J, Nikolova D, Weingarten R, Johnson X, Richaud P, Peltier G, Hermann M, Magneschi L, Hippler M. Deletion of Proton Gradient Regulation 5 (PGR5) and PGR5-Like 1 (PGRL1) proteins promote sustainable light-driven hydrogen production in Chlamydomonas reinhardtii due to increased PSII activity under sulfur deprivation. FRONTIERS IN PLANT SCIENCE 2015; 6:892. [PMID: 26579146 PMCID: PMC4621405 DOI: 10.3389/fpls.2015.00892] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/07/2015] [Indexed: 05/19/2023]
Abstract
Continuous hydrogen photo-production under sulfur deprivation was studied in the Chlamydomonas reinhardtii pgr5 pgrl1 double mutant and respective single mutants. Under medium light conditions, the pgr5 exhibited the highest performance and produced about eight times more hydrogen than the wild type, making pgr5 one of the most efficient hydrogen producer reported so far. The pgr5 pgrl1 double mutant showed an increased hydrogen burst at the beginning of sulfur deprivation under high light conditions, but in this case the overall amount of hydrogen produced by pgr5 pgrl1 as well as pgr5 was diminished due to photo-inhibition and increased degradation of PSI. In contrast, the pgrl1 was effective in hydrogen production in both high and low light. Blocking photosynthetic electron transfer by DCMU stopped hydrogen production almost completely in the mutant strains, indicating that the main pathway of electrons toward enhanced hydrogen production is via linear electron transport. Indeed, PSII remained more active and stable in the pgr mutant strains as compared to the wild type. Since transition to anaerobiosis was faster and could be maintained due to an increased oxygen consumption capacity, this likely preserves PSII from photo-oxidative damage in the pgr mutants. Hence, we conclude that increased hydrogen production under sulfur deprivation in the pgr5 and pgrl1 mutants is caused by an increased stability of PSII permitting sustainable light-driven hydrogen production in Chlamydomonas reinhardtii.
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Affiliation(s)
- Janina Steinbeck
- Institute of Plant Biology and Biotechnology, University of MünsterMünster, Germany
| | - Denitsa Nikolova
- Institute of Plant Biology and Biotechnology, University of MünsterMünster, Germany
| | - Robert Weingarten
- Institute of Plant Biology and Biotechnology, University of MünsterMünster, Germany
| | - Xenie Johnson
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Institut de Biologie Environnementale et de Biotechnologie, Direction des Sciences du Vivant, Commissariat à l’Energie Atomique et aux Energies AlternativesSaint-Paul-lez-Durance, France
- CNRS, UMR 7265, Biologie Végétale et Microbiologie EnvironnementaleSaint-Paul-lez-Durance, France
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Aix Marseille UniversitéSaint-Paul-lez-Durance, France
| | - Pierre Richaud
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Institut de Biologie Environnementale et de Biotechnologie, Direction des Sciences du Vivant, Commissariat à l’Energie Atomique et aux Energies AlternativesSaint-Paul-lez-Durance, France
- CNRS, UMR 7265, Biologie Végétale et Microbiologie EnvironnementaleSaint-Paul-lez-Durance, France
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Aix Marseille UniversitéSaint-Paul-lez-Durance, France
| | - Gilles Peltier
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Institut de Biologie Environnementale et de Biotechnologie, Direction des Sciences du Vivant, Commissariat à l’Energie Atomique et aux Energies AlternativesSaint-Paul-lez-Durance, France
- CNRS, UMR 7265, Biologie Végétale et Microbiologie EnvironnementaleSaint-Paul-lez-Durance, France
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Aix Marseille UniversitéSaint-Paul-lez-Durance, France
| | - Marita Hermann
- Institute of Plant Biology and Biotechnology, University of MünsterMünster, Germany
| | - Leonardo Magneschi
- Institute of Plant Biology and Biotechnology, University of MünsterMünster, Germany
| | - Michael Hippler
- Institute of Plant Biology and Biotechnology, University of MünsterMünster, Germany
- *Correspondence: Michael Hippler,
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Dang KV, Plet J, Tolleter D, Jokel M, Cuiné S, Carrier P, Auroy P, Richaud P, Johnson X, Alric J, Allahverdiyeva Y, Peltier G. Combined increases in mitochondrial cooperation and oxygen photoreduction compensate for deficiency in cyclic electron flow in Chlamydomonas reinhardtii. THE PLANT CELL 2014; 26:3036-50. [PMID: 24989042 PMCID: PMC4145130 DOI: 10.1105/tpc.114.126375] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
During oxygenic photosynthesis, metabolic reactions of CO2 fixation require more ATP than is supplied by the linear electron flow operating from photosystem II to photosystem I (PSI). Different mechanisms, such as cyclic electron flow (CEF) around PSI, have been proposed to participate in reequilibrating the ATP/NADPH balance. To determine the contribution of CEF to microalgal biomass productivity, here, we studied photosynthesis and growth performances of a knockout Chlamydomonas reinhardtii mutant (pgrl1) deficient in PROTON GRADIENT REGULATION LIKE1 (PGRL1)-mediated CEF. Steady state biomass productivity of the pgrl1 mutant, measured in photobioreactors operated as turbidostats, was similar to its wild-type progenitor under a wide range of illumination and CO2 concentrations. Several changes were observed in pgrl1, including higher sensitivity of photosynthesis to mitochondrial inhibitors, increased light-dependent O2 uptake, and increased amounts of flavodiiron (FLV) proteins. We conclude that a combination of mitochondrial cooperation and oxygen photoreduction downstream of PSI (Mehler reactions) supplies extra ATP for photosynthesis in the pgrl1 mutant, resulting in normal biomass productivity under steady state conditions. The lower biomass productivity observed in the pgrl1 mutant in fluctuating light is attributed to an inability of compensation mechanisms to respond to a rapid increase in ATP demand.
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Affiliation(s)
- Kieu-Van Dang
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Julie Plet
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Dimitri Tolleter
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Martina Jokel
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| | - Stéphan Cuiné
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Patrick Carrier
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Pascaline Auroy
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Pierre Richaud
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Xenie Johnson
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Jean Alric
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Yagut Allahverdiyeva
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| | - Gilles Peltier
- CEA, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, F-13108 Saint-Paul-lez-Durance, France CNRS, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France Aix Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
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20
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Baltz A, Dang KV, Beyly A, Auroy P, Richaud P, Cournac L, Peltier G. Plastidial Expression of Type II NAD(P)H Dehydrogenase Increases the Reducing State of Plastoquinones and Hydrogen Photoproduction Rate by the Indirect Pathway in Chlamydomonas reinhardtii1. PLANT PHYSIOLOGY 2014; 165:1344-1352. [PMID: 24820024 PMCID: PMC4081341 DOI: 10.1104/pp.114.240432] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 05/06/2014] [Indexed: 05/21/2023]
Abstract
Biological conversion of solar energy into hydrogen is naturally realized by some microalgae species due to a coupling between the photosynthetic electron transport chain and a plastidial hydrogenase. While promising for the production of clean and sustainable hydrogen, this process requires improvement to be economically viable. Two pathways, called direct and indirect photoproduction, lead to sustained hydrogen production in sulfur-deprived Chlamydomonas reinhardtii cultures. The indirect pathway allows an efficient time-based separation of O2 and H2 production, thus overcoming the O2 sensitivity of the hydrogenase, but its activity is low. With the aim of identifying the limiting step of hydrogen production, we succeeded in overexpressing the plastidial type II NAD(P)H dehydrogenase (NDA2). We report that transplastomic strains overexpressing NDA2 show an increased activity of nonphotochemical reduction of plastoquinones (PQs). While hydrogen production by the direct pathway, involving the linear electron flow from photosystem II to photosystem I, was not affected by NDA2 overexpression, the rate of hydrogen production by the indirect pathway was increased in conditions, such as nutrient limitation, where soluble electron donors are not limiting. An increased intracellular starch was observed in response to nutrient deprivation in strains overexpressing NDA2. It is concluded that activity of the indirect pathway is limited by the nonphotochemical reduction of PQs, either by the pool size of soluble electron donors or by the PQ-reducing activity of NDA2 in nutrient-limited conditions. We discuss these data in relation to limitations and biotechnological improvement of hydrogen photoproduction in microalgae.
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Affiliation(s)
- Anthony Baltz
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Centre de Cadarache, F-13108 Saint-Paul-lez-Durance, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France; andAix Marseille Université, Unité Mixte de Recherche Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Kieu-Van Dang
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Centre de Cadarache, F-13108 Saint-Paul-lez-Durance, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France; andAix Marseille Université, Unité Mixte de Recherche Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Audrey Beyly
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Centre de Cadarache, F-13108 Saint-Paul-lez-Durance, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France; andAix Marseille Université, Unité Mixte de Recherche Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Pascaline Auroy
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Centre de Cadarache, F-13108 Saint-Paul-lez-Durance, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France; andAix Marseille Université, Unité Mixte de Recherche Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Pierre Richaud
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Centre de Cadarache, F-13108 Saint-Paul-lez-Durance, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France; andAix Marseille Université, Unité Mixte de Recherche Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Laurent Cournac
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Centre de Cadarache, F-13108 Saint-Paul-lez-Durance, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France; andAix Marseille Université, Unité Mixte de Recherche Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
| | - Gilles Peltier
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Centre de Cadarache, F-13108 Saint-Paul-lez-Durance, France;Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementale, F-13108 Saint-Paul-lez-Durance, France; andAix Marseille Université, Unité Mixte de Recherche Biologie Végétale et Microbiologie Environnementale, F-13284 Marseille, France
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Central carbon metabolism and electron transport in Chlamydomonas reinhardtii: metabolic constraints for carbon partitioning between oil and starch. EUKARYOTIC CELL 2013; 12:776-93. [PMID: 23543671 DOI: 10.1128/ec.00318-12] [Citation(s) in RCA: 215] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The metabolism of microalgae is so flexible that it is not an easy task to give a comprehensive description of the interplay between the various metabolic pathways. There are, however, constraints that govern central carbon metabolism in Chlamydomonas reinhardtii that are revealed by the compartmentalization and regulation of the pathways and their relation to key cellular processes such as cell motility, division, carbon uptake and partitioning, external and internal rhythms, and nutrient stress. Both photosynthetic and mitochondrial electron transfer provide energy for metabolic processes and how energy transfer impacts metabolism and vice versa is a means of exploring the regulation and function of these pathways. A key example is the specific chloroplast localization of glycolysis/gluconeogenesis and how it impacts the redox poise and ATP budget of the plastid in the dark. To compare starch and lipids as carbon reserves, their value can be calculated in terms of NAD(P)H and ATP. As microalgae are now considered a potential renewable feedstock, we examine current work on the subject and also explore the possibility of rerouting metabolism toward lipid production.
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Tolleter D, Ghysels B, Alric J, Petroutsos D, Tolstygina I, Krawietz D, Happe T, Auroy P, Adriano JM, Beyly A, Cuiné S, Plet J, Reiter IM, Genty B, Cournac L, Hippler M, Peltier G. Control of hydrogen photoproduction by the proton gradient generated by cyclic electron flow in Chlamydomonas reinhardtii. THE PLANT CELL 2011; 23:2619-30. [PMID: 21764992 PMCID: PMC3226202 DOI: 10.1105/tpc.111.086876] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 06/21/2011] [Accepted: 07/02/2011] [Indexed: 05/18/2023]
Abstract
Hydrogen photoproduction by eukaryotic microalgae results from a connection between the photosynthetic electron transport chain and a plastidial hydrogenase. Algal H₂ production is a transitory phenomenon under most natural conditions, often viewed as a safety valve protecting the photosynthetic electron transport chain from overreduction. From the colony screening of an insertion mutant library of the unicellular green alga Chlamydomonas reinhardtii based on the analysis of dark-light chlorophyll fluorescence transients, we isolated a mutant impaired in cyclic electron flow around photosystem I (CEF) due to a defect in the Proton Gradient Regulation Like1 (PGRL1) protein. Under aerobiosis, nonphotochemical quenching of fluorescence (NPQ) is strongly decreased in pgrl1. Under anaerobiosis, H₂ photoproduction is strongly enhanced in the pgrl1 mutant, both during short-term and long-term measurements (in conditions of sulfur deprivation). Based on the light dependence of NPQ and hydrogen production, as well as on the enhanced hydrogen production observed in the wild-type strain in the presence of the uncoupling agent carbonyl cyanide p-trifluoromethoxyphenylhydrazone, we conclude that the proton gradient generated by CEF provokes a strong inhibition of electron supply to the hydrogenase in the wild-type strain, which is released in the pgrl1 mutant. Regulation of the trans-thylakoidal proton gradient by monitoring pgrl1 expression opens new perspectives toward reprogramming the cellular metabolism of microalgae for enhanced H₂ production.
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Affiliation(s)
- Dimitri Tolleter
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
| | - Bart Ghysels
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
| | - Jean Alric
- Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie-Paris 6, 75005 Paris, France
| | - Dimitris Petroutsos
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany
| | - Irina Tolstygina
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany
| | - Danuta Krawietz
- Ruhr University Bochum, Department of Biology and Biotechnology, AG Photobiotechnology, 44780 Bochum, Germany
| | - Thomas Happe
- Ruhr University Bochum, Department of Biology and Biotechnology, AG Photobiotechnology, 44780 Bochum, Germany
| | - Pascaline Auroy
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
| | - Jean-Marc Adriano
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
| | - Audrey Beyly
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
| | - Stéphan Cuiné
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
| | - Julie Plet
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
| | - Ilja M. Reiter
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire d’Ecophysiologie Moléculaire des Plantes, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Bernard Genty
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire d’Ecophysiologie Moléculaire des Plantes, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Laurent Cournac
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
| | - Michael Hippler
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany
| | - Gilles Peltier
- Commissariat à l’Energie Atomique et aux Energies Alternatives, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Commissariat à l’Energie Atomique Cadarache, 13108 Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Aix Marseille Université, Unité Mixte de Recherche 6191 Biologie Végétale et Microbiologie Environnementale, 13108 Saint-Paul-lez-Durance, France
- Address correspondence to
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23
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Rochaix JD. Reprint of: Regulation of photosynthetic electron transport. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:878-86. [PMID: 21605544 DOI: 10.1016/j.bbabio.2011.05.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/11/2010] [Accepted: 11/13/2010] [Indexed: 11/28/2022]
Abstract
The photosynthetic electron transport chain consists of photosystem II, the cytochrome b(6)f complex, photosystem I, and the free electron carriers plastoquinone and plastocyanin. Light-driven charge separation events occur at the level of photosystem II and photosystem I, which are associated at one end of the chain with the oxidation of water followed by electron flow along the electron transport chain and concomitant pumping of protons into the thylakoid lumen, which is used by the ATP synthase to generate ATP. At the other end of the chain reducing power is generated, which together with ATP is used for CO(2) assimilation. A remarkable feature of the photosynthetic apparatus is its ability to adapt to changes in environmental conditions by sensing light quality and quantity, CO(2) levels, temperature, and nutrient availability. These acclimation responses involve a complex signaling network in the chloroplasts comprising the thylakoid protein kinases Stt7/STN7 and Stl1/STN7 and the phosphatase PPH1/TAP38, which play important roles in state transitions and in the regulation of electron flow as well as in thylakoid membrane folding. The activity of some of these enzymes is closely connected to the redox state of the plastoquinone pool, and they appear to be involved both in short-term and long-term acclimation. This article is part of a Special Issue entitled: Regulation of Electron Transport in Chloroplasts.
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24
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Rochaix JD. Regulation of photosynthetic electron transport. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1807:375-83. [PMID: 21118674 DOI: 10.1016/j.bbabio.2010.11.010] [Citation(s) in RCA: 170] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/11/2010] [Accepted: 11/13/2010] [Indexed: 11/30/2022]
Abstract
The photosynthetic electron transport chain consists of photosystem II, the cytochrome b(6)f complex, photosystem I, and the free electron carriers plastoquinone and plastocyanin. Light-driven charge separation events occur at the level of photosystem II and photosystem I, which are associated at one end of the chain with the oxidation of water followed by electron flow along the electron transport chain and concomitant pumping of protons into the thylakoid lumen, which is used by the ATP synthase to generate ATP. At the other end of the chain reducing power is generated, which together with ATP is used for CO(2) assimilation. A remarkable feature of the photosynthetic apparatus is its ability to adapt to changes in environmental conditions by sensing light quality and quantity, CO(2) levels, temperature, and nutrient availability. These acclimation responses involve a complex signaling network in the chloroplasts comprising the thylakoid protein kinases Stt7/STN7 and Stl1/STN7 and the phosphatase PPH1/TAP38, which play important roles in state transitions and in the regulation of electron flow as well as in thylakoid membrane folding. The activity of some of these enzymes is closely connected to the redox state of the plastoquinone pool, and they appear to be involved both in short-term and long-term acclimation. This article is part of a Special Issue entitled "Regulation of Electron Transport in Chloroplasts".
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Affiliation(s)
- Jean-David Rochaix
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland.
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25
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Peltier G, Tolleter D, Billon E, Cournac L. Auxiliary electron transport pathways in chloroplasts of microalgae. PHOTOSYNTHESIS RESEARCH 2010; 106:19-31. [PMID: 20607407 DOI: 10.1007/s11120-010-9575-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 06/16/2010] [Indexed: 05/11/2023]
Abstract
Microalgae are photosynthetic organisms which cover an extraordinary phylogenic diversity and have colonized extremely diverse habitats. Adaptation to contrasted environments in terms of light and nutrient's availabilities has been possible through a high flexibility of the photosynthetic machinery. Indeed, optimal functioning of photosynthesis in changing environments requires a fine tuning between the conversion of light energy by photosystems and its use by metabolic reaction, a particularly important parameter being the balance between phosphorylating (ATP) and reducing (NADPH) power supplies. In addition to the main route of electrons operating during oxygenic photosynthesis, called linear electron flow or Z scheme, auxiliary routes of electron transfer in interaction with the main pathway have been described. These reactions which include non-photochemical reduction of intersystem electron carriers, cyclic electron flow around PSI, oxidation by molecular O(2) of the PQ pool or of the PSI electron acceptors, participate in the flexibility of photosynthesis by avoiding over-reduction of electron carriers and modulating the NADPH/ATP ratio depending on the metabolic demand. Forward or reverse genetic approaches performed in model organisms such as Arabidopsis thaliana for higher plants, Chlamydomonas reinhardtii for green algae and Synechocystis for cyanobacteria allowed identifying molecular components involved in these auxiliary electron transport pathways, including Ndh-1, Ndh-2, PGR5, PGRL1, PTOX and flavodiiron proteins. In this article, we discuss the diversity of auxiliary routes of electron transport in microalgae, with particular focus in the presence of these components in the microalgal genomes recently sequenced. We discuss how these auxiliary mechanisms of electron transport may have contributed to the adaptation of microalgal photosynthesis to diverse and changing environments.
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Affiliation(s)
- Gilles Peltier
- CEA, Direction des Sciences du Vivant, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, Saint-Paul-lez-Durance 13108, France.
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26
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Impaired respiration discloses the physiological significance of state transitions in Chlamydomonas. Proc Natl Acad Sci U S A 2009; 106:15979-84. [PMID: 19805237 DOI: 10.1073/pnas.0908111106] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
State transitions correspond to a major regulation process for photosynthesis, whereby chlorophyll protein complexes responsible for light harvesting migrate between photosystem II and photosystem I in response to changes in the redox poise of the intersystem electron carriers. Here we disclose their physiological significance in Chlamydomonas reinhardtii using a genetic approach. Using single and double mutants defective for state transitions and/or mitochondrial respiration, we show that photosynthetic growth, and therefore biomass production, critically depends on state transitions in respiratory-defective conditions. When extra ATP cannot be provided by respiration, enhanced photosystem I turnover elicited by transition to state 2 is required for photosynthetic activity. Concomitant impairment of state transitions and respiration decreases the overall yield of photosynthesis, ultimately leading to reduced fitness. We thus provide experimental evidence that the combined energetic contributions of state transitions and respiration are required for efficient carbon assimilation in this alga.
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27
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Alric J, Lavergne J, Rappaport F. Redox and ATP control of photosynthetic cyclic electron flow in Chlamydomonas reinhardtii (I) aerobic conditions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1797:44-51. [PMID: 19651104 DOI: 10.1016/j.bbabio.2009.07.009] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 07/22/2009] [Accepted: 07/24/2009] [Indexed: 11/16/2022]
Abstract
Assimilation of atmospheric CO2 by photosynthetic organisms such as plants, cyanobacteria and green algae, requires the production of ATP and NADPH in a ratio of 3:2. The oxygenic photosynthetic chain can function following two different modes: the linear electron flow which produces reducing power and ATP, and the cyclic electron flow which only produces ATP. Some regulation between the linear and cyclic flows is required for adjusting the stoichiometric production of high-energy bonds and reducing power. Here we explore, in the green alga Chlamydomonas reinhardtii, the onset of the cyclic electron flow during a continuous illumination under aerobic conditions. In mutants devoid of Rubisco or ATPase, where the reducing power cannot be used for carbon fixation, we observed a stimulation of the cyclic electron flow. The present data show that the cyclic electron flow can operate under aerobic conditions and support a simple competition model where the excess reducing power is recycled to match the demand for ATP.
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Affiliation(s)
- Jean Alric
- UMR 7141, CNRS et Université Pierre et Marie Curie (Paris VI), Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie 75005 Paris, France.
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Abstract
Despite recent elucidation of the three-dimensional structure of major photosynthetic complexes, our understanding of light energy conversion in plant chloroplasts and microalgae under physiological conditions requires exploring the dynamics of photosynthesis. The photosynthetic apparatus is a flexible molecular machine that can acclimate to metabolic and light fluctuations in a matter of seconds and minutes. On a longer time scale, changes in environmental cues trigger acclimation responses that elicit intracellular signaling between the nucleo-cytosol and chloroplast resulting in modification of the biogenesis of the photosynthetic machinery. Here we attempt to integrate well-established knowledge on the functional flexibility of light-harvesting and electron transfer processes, which has greatly benefited from genetic approaches, with data derived from the wealth of recent transcriptomic and proteomic studies of acclimation responses in photosynthetic eukaroytes.
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Affiliation(s)
- Stephan Eberhard
- Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, F-75005 Paris, France
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29
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Forti G. The role of respiration in the activation of photosynthesis upon illumination of dark adapted Chlamydomonas reinhardtii. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:1449-54. [PMID: 18823936 DOI: 10.1016/j.bbabio.2008.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 08/28/2008] [Accepted: 08/29/2008] [Indexed: 10/21/2022]
Abstract
It is reported that O(2) is required for the activation of photosynthesis in dark adapted Chlamydomonas reinhardtii in State 1, under low light intensity. The concentration of dissolved O(2) of ca. 9 microM is sufficient to saturate the requirement. When the concentration of O(2) is 3 muM or below, the activation of photosynthesis is strongly inhibited by myxothiazol, a specific inhibitor of the mitochondrial cytochrome bc(1). The effect of this inhibitor decreases as the O(2) concentration is raised, to disappear completely above 50 muM. Low concentrations of uncouplers delay the activation of photosynthesis, but do not inhibit it when steady state is reached. It is concluded that in State 1 C. reinhardtii mitochondrial respiration is required for the activation of photosynthesis upon illumination of dark adapted cells only when the concentration of O(2) is too low (less than 5 muM) to allow an appreciable activity of the Mehler reaction. The role of respiration does not seem to be due to the synthesis of ATP by oxidative phosphorylation, because photosynthesis activation is not sensitive to oligomycin.
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Affiliation(s)
- Giorgio Forti
- Dipartimento di Biologia dell'Università e Istituto di Biofisica del CNR - Via Celoria 26, Milano 20133, Italy.
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30
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Braun NA, Davis AW, Theg SM. The chloroplast Tat pathway utilizes the transmembrane electric potential as an energy source. Biophys J 2007; 93:1993-8. [PMID: 17513364 PMCID: PMC1959559 DOI: 10.1529/biophysj.106.098731] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Accepted: 05/02/2007] [Indexed: 11/18/2022] Open
Abstract
The thylakoid membrane, located inside the chloroplast, requires proteins transported across it for plastid biogenesis and functional photosynthetic electron transport. The chloroplast Tat translocator found on thylakoids transports proteins from the plastid stroma to the thylakoid lumen. Previous studies have shown that the chloroplast Tat pathway is independent of NTP hydrolysis as an energy source and instead depends on the thylakoid transmembrane proton gradient to power protein translocation. Because of its localization on the same membrane as the proton motive force-dependent F(0)F(1) ATPase, we believed that the chloroplast Tat pathway also made use of the thylakoid electric potential for transporting substrates. By adjusting the rate of photosynthetic proton pumping and by utilizing ionophores, we show that the chloroplast Tat pathway can also utilize the transmembrane electric potential for protein transport. Our findings indicate that the chloroplast Tat pathway is likely dependent on the total protonmotive force (PMF) as an energy source. As a protonmotive-dependent device, certain predictions can be made about structural features expected to be found in the Tat translocon, specifically, the presence of a proton well, a device in the membrane that converts electrical potential into chemical potential.
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Affiliation(s)
- Nikolai A Braun
- Department of Plant Biology, University of California, Davis, CA 95616, USA
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31
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Radchenko IG, Il’yash LV. Growth and photosynthetic activity of diatom Thalassiosira weissflogii at decreasing salinity. BIOL BULL+ 2006. [DOI: 10.1134/s106235900603006x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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Aichinger N, Lütz-Meindl U. Organelle interactions and possible degradation pathways visualized in high-pressure frozen algal cells. J Microsc 2005; 219:86-94. [PMID: 16159344 DOI: 10.1111/j.1365-2818.2005.01496.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Summary Organelle interactions, although essential for both anabolic and catabolic pathways in plant cells have not been examined in detail so far. In the present study the structure of different organelle-organelle, organelle-vesicle and organelle-membrane interactions were investigated in growing and nongrowing cells of the green alga Micrasterias denticulata by use of high pressure freeze fixation and energy filtering transmission electron microscopy. It became clear that contacts between mitochondria always occur by formation of a cone-shaped protuberance of one of the mitochondria which penetrates into its fusion partner. In the same way, structural interactions between mitochondria and mucilage vesicles and between microbodies and mucilage vesicles are achieved. Lytic compartments contact mitochondria or mucilage vesicles again by forming protuberances and by extending their contents into the respective compartment. Detached portions of mitochondria are found inside lytic compartments as a consequence of such interactions. Mitochondria found in contact with the plasma membrane reveal structural disintegration. Our study shows that interactions of organelles and vesicles are frequent events in Micrasterias cells of different ages. The interactive contacts between lytic compartments and organelles or vesicles suggest a degradation pathway different from autophagy processes described in the literature. Both the interactions between vesicles and organelles and the degradation pathways occur independently from cytoskeleton function as demonstrated by use of cytochalasin D and the microtubule inhibitor amiprophos-methyl.
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Affiliation(s)
- N Aichinger
- Plant Physiology, Cell Biology Department, University of Salzburg, Austria
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33
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Jiao S, Thornsberry JM, Elthon TE, Newton KJ. Biochemical and molecular characterization of photosystem I deficiency in the NCS6 mitochondrial mutant of maize. PLANT MOLECULAR BIOLOGY 2005; 57:303-313. [PMID: 15821884 DOI: 10.1007/s11103-004-7792-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Accepted: 12/17/2004] [Indexed: 05/24/2023]
Abstract
Interorganellar signaling interactions are poorly understood. The maize non-chromosomal stripe (NCS) mutants provide models to study the requirement of mitochondrial function for chloroplast biogenesis and photosynthesis. Previous work suggested that the NCS6 mitochondrial mutation, a cytochrome oxidase subunit 2 (cox2) deletion, is associated with a malfunction of Photosystem I (PSI) in defective chloroplasts of mutant leaf sectors (Gu et al., 1993). We have now quantified the reductions of photosynthetic rates and PSI activity in the NCS6 defective stripes. Major reductions of the plastid-coded PsaC and nucleus-coded PsaD and PsaE PSI subunits and of their corresponding mRNAs are seen in mutant sectors; however, although the psaA/B mRNA is greatly reduced, levels of PsaA and PsaB (the core proteins of PSI) are only slightly decreased. Levels of the PsaL subunit and its mRNA appear to be unchanged. Tested subunits of other thylakoid membrane complexes--PSII, Cyt b6/f, and ATP synthase, have minor (or no) reductions within mutant sectors. The results suggest that specific signaling pathways sense the dysfunction of the mitochondrial electron transport chain and respond to down-regulate particular PSI mRNAs, leading to decreased PSI accumulation in the chloroplast. The reductions of both nucleus and plastid encoded components indicate that complex interorganellar signaling pathways may be involved.
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Affiliation(s)
- Shunxing Jiao
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA
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34
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Johnson E, Anastasios M. Functional characterization of Chlamydomonas reinhardtii with alterations in the atpE gene. PHOTOSYNTHESIS RESEARCH 2004; 82:131-40. [PMID: 16151869 DOI: 10.1007/s11120-004-6567-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The FUD17 strain of Chlamydomonas reinhardtii is a photosynthesis-deficient, acetate-requiring mutant with a defect in the chloroplast atpE gene, which codes for the epsilon subunit of the chloroplast ATP synthase. In this work, the FUD17 mutant was examined in relation to other known ATP synthase mutants as an initial step toward using this strain to generate altered versions of the atpE gene for site-directed mutagenesis of the epsilon subunit. The FUD17 strain grows well and is normally pigmented in the dark (heterotrophic conditions), but cannot grow autotrophically in the light, even when media are supplemented with acetate. Under heterotrophic conditions, it shows no accumulation of the epsilon subunit, and much lower levels of the alpha and beta subunits of the chloroplast ATP synthase. FUD17 shows no light-dependent oxygen evolution and shows a strong, light-dependent alteration in its chlorophyll fluorescence. These results show that FUD17 possesses similar characteristics to other ATP synthase mutants and fails to express an assembled ATP synthase complex on its thylakoid membrane. A preliminary attempt at site-directed mutagenesis is described which produced a slightly truncated form of the epsilon subunit, which is expressed normally in the cell.
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Affiliation(s)
- Eric Johnson
- Department of Biology, Johns Hopkins University, Mudd, Hall 3400 N. Charles St, MD, USA
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35
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Raghavendra AS, Padmasree K. Beneficial interactions of mitochondrial metabolism with photosynthetic carbon assimilation. TRENDS IN PLANT SCIENCE 2003; 8:546-53. [PMID: 14607100 DOI: 10.1016/j.tplants.2003.09.015] [Citation(s) in RCA: 280] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Chloroplasts and mitochondria are traditionally considered to be autonomous organelles but they are not as independent as they were once thought to be. Mitochondrial metabolism, particularly the bioenergetic reactions of oxidative electron transport and phosphorylation, continue to be active in the light and are essential for sustaining photosynthetic carbon assimilation. The marked and mutually beneficial interaction between mitochondria and chloroplasts is intriguing. The key compartments within plant cells, including not only mitochondria and chloroplasts but also the peroxisomes and cytosol, appear to be in a delicate metabolic equilibrium. Disturbance of any of these compartments perturbs the metabolism of whole cell. Nevertheless, mitochondria appear to be the key players because they function during both photorespiration and dark respiration.
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Affiliation(s)
- Agepati S Raghavendra
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, 500 046, Hyderabad, India.
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36
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Forti G, Furia A, Bombelli P, Finazzi G. In vivo changes of the oxidation-reduction state of NADP and of the ATP/ADP cellular ratio linked to the photosynthetic activity in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2003; 132:1464-74. [PMID: 12857827 PMCID: PMC167085 DOI: 10.1104/pp.102.018861] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2002] [Revised: 01/15/2003] [Accepted: 01/28/2003] [Indexed: 05/18/2023]
Abstract
The ATP/ADP and NADP/NADPH ratios have been measured in whole-cell extract of the green alga Chlamydomonas reinhardtii, to understand their availability for CO(2) assimilation by the Calvin cycle in vivo. Measurements were performed during the dark-light transition of both aerobic and anaerobic cells, under illumination with saturating or low light intensity. Two different patterns of behavior were observed: (a) In anaerobic cells, during the lag preceding O(2) evolution, ATP was synthesized without changes in the NADP/NADPH ratio, consistently with the operation of cyclic electron flow. (b) In aerobiosis, illumination increased the ATP/ADP ratio independently of the intensity used, whereas the amount of NADPH was decreased at limiting photon flux and regained the dark-adapted level under saturating photon flux. Moreover, under these conditions, the addition of low concentrations of uncouplers stimulated photosynthetic O(2) evolution. These observations suggest that the photosynthetic generation of reducing equivalents rather than the rate of ATP formation limits the photosynthetic assimilation of CO(2) in C. reinhardtii cells. This situation is peculiar to C. reinhardtii, because neither NADPH nor ATP limited this process in plant leaves, as shown by their increase upon illumination in barley (Hordeum vulgare) leaves, independent of light intensity. Experiments are presented and were designed to evaluate the contribution of different physiological processes that might increase the photosynthetic ATP/NADPH ratio-the Mehler reaction, respiratory ATP supply following the transfer of reducing equivalents via the malate/oxaloacetate shuttle, and cyclic electron flow around PSI-to this metabolic situation.
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Affiliation(s)
- Giorgio Forti
- Istituto di Biofisica del Consiglio Nazionale delle Ricerche, Sezione di Milano, Dipartimento di Biologia dell'Università di Milano, Via Celoria 26, Milano 20133, Italy.
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37
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Abstract
The term 'chlororespiration' is used to describe the activity of a putative respiratory electron transler chain within the thylakoid membrane of chloroplasts and was originally proposed by Bennouon in 1982 to explain effects on the redox state of the plastoquinone pool in green algae in the absence of photosynthetic plastoquinone electrontransfer. In his original model, Bennoun suggested that the pool could be reduced through the action of a NAD(P) H dehydrogenase and could be oxidized by oxygen at an oxidase. At the same time an electrochemical gradient would be generated across the membrane. This review describes the current status of the chlororespiration model in light of the recent discoveries of novel respiratory components chloroplast thylakoid membrane.
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Affiliation(s)
- P J Nixon
- Deparlment of Biochemistry, Imperial College of Science, Technology and Medicine, London, UK.
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38
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Neuhaus HE, Wagner R. Solute pores, ion channels, and metabolite transporters in the outer and inner envelope membranes of higher plant plastids. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1465:307-23. [PMID: 10748262 DOI: 10.1016/s0005-2736(00)00146-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
All plant cells contain plastids. Various reactions are located exclusively within these unique organelles, requiring the controlled exchange of a wide range of solutes, ions, and metabolites. In recent years, several proteins involved in import and/or export of these compounds have been characterized using biochemical and electrophysiological approaches, and in addition have been identified at the molecular level. Several solute channels have been identified in the outer envelope membrane. These porin-like proteins in the outer envelope membrane were formerly thought to be quite unspecific, but have now been shown to exhibit significant substrate specificity and to be highly regulated. Therefore, the inter-envelope membrane space is not as freely accessible as previously thought. Transport proteins in the inner envelope membrane have been characterized in more detail. It has been proved unequivocally that a family of proteins (including triose phosphate-/phosphoenolpyruvate-, and glucose 6-phosphate-specific transporters) permit the exchange of inorganic phosphate and phosphorylated intermediates. A new type of plastidic 2-oxoglutarate/malate transporter has been identified and represents the first carrier with 12 putative transmembrane domains, to be located in the inner envelope membrane. The plastidic ATP/ADP transporter also contains 12 putative transmembrane domains and possesses striking structural similarity to ATP/ADP transporters found in intracellular, human pathogenic bacteria.
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Affiliation(s)
- H E Neuhaus
- Pflanzenphysiologie, Universität Kaiserslautern, Postfach 3049, D-67653, Kaiserslautern, Germany.
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Hippler M, Redding K, Rochaix JD. Chlamydomonas genetics, a tool for the study of bioenergetic pathways. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1367:1-62. [PMID: 9784589 DOI: 10.1016/s0005-2728(98)00136-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- M Hippler
- Departments of Molecular Biology and Plant Biology, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva-4, Switzerland
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Cournac L, Redding K, Bennoun P, Peltier G. Limited photosynthetic electron flow but no CO2 fixation in Chlamydomonas mutants lacking photosystem I. FEBS Lett 1997; 416:65-8. [PMID: 9369234 DOI: 10.1016/s0014-5793(97)01170-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
By measuring O2 and CO2 exchange in mutants of the green alga Chlamydomonas reinhardtii in which genes encoding the reaction center of photosystem I (psaA or psaB) have been deleted, we found that a photosystem II-dependent electron flow using O2 as the final acceptor can be sustained in the light. However, in contrast with recent reports using other Chlamydomonas mutants (B4 and F8), we show here that CO2 fixation does not occur in the absence of photosystem I. By deleting the psaA gene in both B4 and F8 strains, we conclude that the ability of these mutants to fix CO2 in the light is due to the presence of residual amounts of photosystem I.
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Affiliation(s)
- L Cournac
- CEA Cadarache, Département d'Ecophysiologie Végétale et de Microbiologie, Saint-Paul-lez-Durance, France
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Avni A, Anderson JD, Holland N, Rochaix JD, Gromet-Elhanan Z, Edelman M. Tentoxin sensitivity of chloroplasts determined by codon 83 of beta subunit of proton-ATPase. Science 1992; 257:1245-7. [PMID: 1387730 DOI: 10.1126/science.1387730] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Tentoxin is a naturally occurring phytotoxic peptide that causes seedling chlorosis and arrests growth in sensitive plants and algae. In vitro, it inhibits activity of the beta subunit of the plastid proton-adenosine triphosphatase (ATPase) from sensitive species. Plastid atpB genes from six closely related, tentoxin-sensitive or -resistant Nicotiana species differ at codon 83, according to their response to the toxin: glutamate correlated with resistance and aspartate correlated with sensitivity. The genetic relevance of this site was confirmed in Chlamydomonas reinhardtii by chloroplast transformation. The alga, normally tentoxin-resistant, was rendered tentoxin-sensitive by mutagenesis of its plastid atpB gene at codon 83. Codon 83 may represent a critical site on the beta subunit that does not compete with nucleotide binding or other catalytic activities.
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Affiliation(s)
- A Avni
- Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel
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Bulté L, Wollman FA. Evidence for a selective destabilization of an integral membrane protein, the cytochrome b6/f complex, during gametogenesis in Chlamydomonas reinhardtii. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 204:327-36. [PMID: 1740146 DOI: 10.1111/j.1432-1033.1992.tb16641.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We studied the process of photosynthetic inactivation during gametogenesis of the unicellular green alga Chlamydomonas reinhardtii. We show that it is caused by the selective destabilization of a single transmembrane protein complex, the cytochrome b6/f complex, which is initially accumulated in the thylakoid membranes of vegetative cells. This protein destabilization is controlled by the intracellular energy sources available in the gametes, i.e. the coupled electron flow in the mitochondria and the amount of starch accumulated in the chloroplast. It nevertheless requires the expression of gamete-specific proteins. The loss of cytochrome b6/f complexes during gametogenesis is prevented by the addition of cycloheximide, but is chloramphenicol insensitive. Therefore, it is likely to involve some translation product of nuclear origin, specifically expressed during gametogenesis. Among the new polypeptides specifically found in the gametes, we detected a soluble polypeptide M alpha (approximate molecular mass of 63 kDa), which shared common epitopes with cytochrome f. Its synthesis displays an antibiotic sensitivity typical of a nuclear-encoded polypeptide and is controlled by the same intracellular signals which control the destabilization of the cytochrome b6/f complexes in the thylakoid membranes.
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Affiliation(s)
- L Bulté
- Service de Photosynthèse, Institut de Biologie Physico-Chimique, Paris, France
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Cox G, Devenish R, Gibson F, Howitt S, Nagley P. Chapter 12 The structure and assembly of ATP synthase. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/s0167-7306(08)60180-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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Pozueta-Romero J, Viale AM, Akazawa T. Comparative analysis of mitochondrial and amyloplast adenylate translocators. FEBS Lett 1991; 287:62-6. [PMID: 1879538 DOI: 10.1016/0014-5793(91)80016-v] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Structurally intact and metabolically competent mitochondria isolated from liquid-culture cells of sycamore (Acer pseudoplatanus L.) were shown to incorporate ADPglucose. Employing the double silicone oil layer filtering centrifugation method, we examined the kinetic properties of the uptake of various adenylates as well as the inhibitory effects exerted by carboxyatractyloside, atractyloside and bongkrekic acid, known specific inhibitors of the mitochondrial adenylate translocator. Immunoblot patterns of peptides derived from the partial proteolytic digestion of the mitochondrial and plastid adenylate translocators were shown to be essentially the same. We conclude that the molecular entities engaged in the adenylate transport system operating in two different organelles, mitochondria and amyloplasts, are very similar.
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Affiliation(s)
- J Pozueta-Romero
- Research Institute for Biochemical Regulation, School of Agriculture, Nagoya University, Japan
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Lin CH, Wu M. A ferredoxin-type iron-sulfur protein gene, frx B, is expressed in the chloroplasts of tobacco and spinach. PLANT MOLECULAR BIOLOGY 1990; 15:449-55. [PMID: 2103463 DOI: 10.1007/bf00019161] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Previously, a ferredoxin-type iron-sulfur protein, frx B protein, was identified in a high-salt extract of the purified thylakoid membrane of Chlamydomonas reinhardtii, a unicellular green alga. Polyclonal antibody was raised against a synthetic pentadecameric peptide with an amino acid sequence corresponding to the highly conserved region of the putative frx B proteins of 3 land plants. In this report, protein(s) reacting strongly and specifically with this antibody was detected in the equivalent high-salt extract prepared from purified chloroplast of spinach and tobacco. One strong reaction polypeptide band from tobacco chloroplast was purified from SDS-polyacrylamide gel and subjected to endoproteinase lys C digestion. The resulting polypeptides were separated by reversed-phase chromatography. N-terminal sequencing of 3 purified polypeptides revealed that the protein is encoded by the 'frxB gene' identified from DNA sequence analysis.
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Affiliation(s)
- C H Lin
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Republic of China
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Garab G, Lajkó F, Mustárdy L, Márton L. Respiratory control over photosynthetic electron transport in chloroplasts of higher-plant cells: evidence for chlororespiration. PLANTA 1989; 179:349-58. [PMID: 24201664 DOI: 10.1007/bf00391080] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/1989] [Accepted: 05/30/1989] [Indexed: 05/16/2023]
Abstract
Flash-induced primary charge separation, detected as electrochromic absorbance change, the operation of the cytochrome b/f complex and the redox state of the plastoquinone pool were measured in leaves, protoplasts and open-cell preparations of tobacco (Nicotiana tabacum L.), and in isolated intact chloroplasts of peas (Pisum sativum L.). Addition of 0.5-5 mM KCN to these samples resulted in a large increase in the slow electrochromic rise originating from the electrogenic activity of the cytochrome b/f complex. The enhancement was also demonstrated by monitoring the absorbance transients of cytochrome f and b 6 between 540 and 572 nm. In isolated, intact chloroplasts with an inhibited photosystem (PS) II, low concentrations of dithionite or ascorbate rendered turnover of only 60% of the PSI reaction centers, KCN being required to reactivate the remainder. "Silent" PSI reaction centers which could be reactivated by KCN were shown to occur in protoplasts both in the absence and presence of a PSII inhibitor. Contrasting spectroscopic data obtained for chloroplasts before and after isolation indicated the existence of a continuous supply of reducing equivalents from the cytosol.Our data indicate that: (i) A respiratory electron-transport pathway involving a cyanide-sensitive component is located in chloroplasts and competes with photosynthetic electron transport for reducing equivalents from the plastoquinone pool. This chlororespiratory pathway appears to be similar to that found in photosynthetic prokaryotes and green algae. (ii) There is an influx of reducing equivalents from the cytosol to the plastoquinone pool. These may be indicative of a complex respiratory control of photosynthetic electron transport in higher-plant cells.
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Affiliation(s)
- G Garab
- Institute of Plant Physiology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, H-6701, Szeged, Hungary
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Wu M, Nie ZQ, Yang J. The 18-kD protein that binds to the chloroplast DNA replicative origin is an iron-sulfur protein related to a subunit of NADH dehydrogenase. THE PLANT CELL 1989; 1:551-557. [PMID: 2562513 PMCID: PMC159789 DOI: 10.1105/tpc.1.5.551] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
From a high-salt extract of the purified thylakoid membrane, an 18-kD protein was detected. This protein was translated by the chloroplast ribosomes and could form a stable DNA-protein complex with a cloned chloroplast DNA replicative origin [Nie, Z.Q., Chang, D.Y., and Wu, M. (1987) Mol. Gen. Genet. 209, 265-269]. In this paper, the 18-kD protein is linked to frxB, a chloroplast-encoded, ferredoxin-type, iron-sulfur protein, by N-terminal microsequencing of the purified protein and computer analysis. The identification is further supported empirically by the fact that the electron paramagnetic resonance spectra of the protein indicate the presence of iron-sulfur clusters. A polyclonal antibody raised against a synthetic pentadecameric peptide with amino acid sequence corresponds to the highly conserved region of the frxB protein and reacts strongly and specifically with the 18-kD protein band in protein gel blot analyses. The 18-kD iron-sulfur protein is found to be related to a subunit of the respiratory chain NADH dehydrogenase by its cross-reaction with a polyclonal antibody raised against highly purified NADH-ubiquinone oxidoreductase, a key enzyme of the respiratory chain. These data are consistent with chlororespiration, and, thus, possible implication of chlororespiration in regulating the initiation of chloroplast DNA replication is discussed.
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Affiliation(s)
- M Wu
- Department of Biological Sciences, University of Maryland, Baltimore 21228
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