1
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Rühle T, Leister D, Pasch V. Chloroplast ATP synthase: From structure to engineering. THE PLANT CELL 2024; 36:3974-3996. [PMID: 38484126 PMCID: PMC11449085 DOI: 10.1093/plcell/koae081] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 12/27/2023] [Indexed: 10/05/2024]
Abstract
F-type ATP synthases are extensively researched protein complexes because of their widespread and central role in energy metabolism. Progress in structural biology, proteomics, and molecular biology has also greatly advanced our understanding of the catalytic mechanism, post-translational modifications, and biogenesis of chloroplast ATP synthases. Given their critical role in light-driven ATP generation, tailoring the activity of chloroplast ATP synthases and modeling approaches can be applied to modulate photosynthesis. In the future, advances in genetic manipulation and protein design tools will significantly expand the scope for testing new strategies in engineering light-driven nanomotors.
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Affiliation(s)
- Thilo Rühle
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-University Munich, D-82152 Planegg-Martinsried, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-University Munich, D-82152 Planegg-Martinsried, Germany
| | - Viviana Pasch
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-University Munich, D-82152 Planegg-Martinsried, Germany
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2
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Tiwari A, Mamedov F, Fitzpatrick D, Gunell S, Tikkanen M, Aro EM. Differential FeS cluster photodamage plays a critical role in regulating excess electron flow through photosystem I. NATURE PLANTS 2024:10.1038/s41477-024-01780-2. [PMID: 39271942 DOI: 10.1038/s41477-024-01780-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 07/31/2024] [Indexed: 09/15/2024]
Abstract
The photosynthetic electron flux from photosystem I (PSI) is mainly directed to NADP+ and CO2 fixation, but a fraction is always shared between alternative and cyclic electron transport. Although the electron transfer from P700 to ferredoxin, via phylloquinone and the FeSX, FeSB and FeSA clusters, is well characterized, the regulatory role of these redox intermediates in the delivery of electrons from PSI to NADP+, alternative and cyclic electron transport under environmental stress remains elusive. Here we provide evidence for sequential damage to PSI FeS clusters under high light and subsequent slow recovery under low light in Arabidopsis thaliana. Wild-type plants showed 10-35% photodamage to their FeSA/B clusters with increasing high-light duration, without much effect on P700 oxidation capacity, FeSX function or CO2 fixation rate, and without additional oxygen consumption (O2 photoreduction). Parallel FeSA/B cluster damage in the pgr5 mutant was more pronounced at 50-85%, probably due to weak photosynthetic control and low non-photochemical quenching. Such severe electron pressure on PSI was also shown to damage the FeSX clusters, with a concomitant decrease in P700 oxidation capacity and a decrease in thylakoid-bound ferredoxin in the pgr5 mutant. The results from wild-type and pgr5 plants reveal controlled damage of PSI FeS clusters under high light. In wild-type plants, this favours electron transport to linear over alternative pathways by intact PSI centres, thereby preventing reactive oxygen species production and probably promoting harmless charge recombination between P700+ and FeSX- as long as the majority of FeSA/B clusters remain functional.
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Affiliation(s)
- Arjun Tiwari
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, Turku, Finland.
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Duncan Fitzpatrick
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | - Sanna Gunell
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | - Mikko Tikkanen
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, Turku, Finland.
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3
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Niu Y, Matsubara S, Nedbal L, Lazár D. Dynamics and interplay of photosynthetic regulatory processes depend on the amplitudes of oscillating light. PLANT, CELL & ENVIRONMENT 2024; 47:2240-2257. [PMID: 38482712 DOI: 10.1111/pce.14879] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 02/28/2024] [Indexed: 04/30/2024]
Abstract
Plants have evolved multiple regulatory mechanisms to cope with natural light fluctuations. The interplay between these mechanisms leads presumably to the resilience of plants in diverse light patterns. We investigated the energy-dependent nonphotochemical quenching (qE) and cyclic electron transports (CET) in light that oscillated with a 60-s period with three different amplitudes. The photosystem I (PSI) and photosystem II (PSII) function-related quantum yields and redox changes of plastocyanin and ferredoxin were measured in Arabidopsis thaliana wild types and mutants with partial defects in qE or CET. The decrease in quantum yield of qE due to the lack of either PsbS- or violaxanthin de-epoxidase was compensated by an increase in the quantum yield of the constitutive nonphotochemical quenching. The mutant lacking NAD(P)H dehydrogenase (NDH)-like-dependent CET had a transient significant PSI acceptor side limitation during the light rising phase under high amplitude of light oscillations. The mutant lacking PGR5/PGRL1-CET restricted electron flows and failed to induce effective photosynthesis control, regardless of oscillation amplitudes. This suggests that PGR5/PGRL1-CET is important for the regulation of PSI function in various amplitudes of light oscillation, while NDH-like-CET acts' as a safety valve under fluctuating light with high amplitude. The results also bespeak interplays among multiple photosynthetic regulatory mechanisms.
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Affiliation(s)
- Yuxi Niu
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, Jülich, Germany
| | - Shizue Matsubara
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, Jülich, Germany
| | - Ladislav Nedbal
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, Jülich, Germany
- Department of Biophysics, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Dušan Lazár
- Department of Biophysics, Faculty of Science, Palacký University, Olomouc, Czech Republic
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4
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Maekawa S, Ohnishi M, Wada S, Ifuku K, Miyake C. Enhanced Reduction of Ferredoxin in PGR5-Deficient Mutant of Arabidopsis thaliana Stimulated Ferredoxin-Dependent Cyclic Electron Flow around Photosystem I. Int J Mol Sci 2024; 25:2677. [PMID: 38473924 DOI: 10.3390/ijms25052677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 02/12/2024] [Accepted: 02/25/2024] [Indexed: 03/14/2024] Open
Abstract
The molecular entity responsible for catalyzing ferredoxin (Fd)-dependent cyclic electron flow around photosystem I (Fd-CEF) remains unidentified. To reveal the in vivo molecular mechanism of Fd-CEF, evaluating ferredoxin reduction-oxidation kinetics proves to be a reliable indicator of Fd-CEF activity. Recent research has demonstrated that the expression of Fd-CEF activity is contingent upon the oxidation of plastoquinone. Moreover, chloroplast NAD(P)H dehydrogenase does not catalyze Fd-CEF in Arabidopsis thaliana. In this study, we analyzed the impact of reduced Fd on Fd-CEF activity by comparing wild-type and pgr5-deficient mutants (pgr5hope1). PGR5 has been proposed as the mediator of Fd-CEF, and pgr5hope1 exhibited a comparable CO2 assimilation rate and the same reduction-oxidation level of PQ as the wild type. However, P700 oxidation was suppressed with highly reduced Fd in pgr5hope1, unlike in the wild type. As anticipated, the Fd-CEF activity was enhanced in pgr5hope1 compared to the wild type, and its activity further increased with the oxidation of PQ due to the elevated CO2 assimilation rate. This in vivo research clearly demonstrates that the expression of Fd-CEF activity requires not only reduced Fd but also oxidized PQ. Importantly, PGR5 was found to not catalyze Fd-CEF, challenging previous assumptions about its role in this process.
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Affiliation(s)
- Shu Maekawa
- Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-Ku, Kobe 657-8501, Japan
| | - Miho Ohnishi
- Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-Ku, Kobe 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Kyoto 606-8502, Japan
| | - Shinya Wada
- Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-Ku, Kobe 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Kyoto 606-8502, Japan
| | - Kentaro Ifuku
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Kyoto 606-8502, Japan
- Graduate School for Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Chikahiro Miyake
- Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-Ku, Kobe 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Kyoto 606-8502, Japan
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5
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Semenov AY, Tikhonov AN. Electrometric and Electron Paramagnetic Resonance Measurements of a Difference in the Transmembrane Electrochemical Potential: Photosynthetic Subcellular Structures and Isolated Pigment-Protein Complexes. MEMBRANES 2023; 13:866. [PMID: 37999352 PMCID: PMC10673362 DOI: 10.3390/membranes13110866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/23/2023] [Accepted: 10/26/2023] [Indexed: 11/25/2023]
Abstract
A transmembrane difference in the electrochemical potentials of protons (ΔμH+) serves as a free energy intermediate in energy-transducing organelles of the living cell. The contributions of two components of the ΔμH+ (electrical, Δψ, and concentrational, ΔpH) to the overall ΔμH+ value depend on the nature and lipid composition of the energy-coupling membrane. In this review, we briefly consider several of the most common instrumental (electrometric and EPR) methods for numerical estimations of Δψ and ΔpH. In particular, the kinetics of the flash-induced electrometrical measurements of Δψ in bacterial chromatophores, isolated bacterial reaction centers, and Photosystems I and II of the oxygenic photosynthesis, as well as the use of pH-sensitive molecular indicators and kinetic data regarding pH-dependent electron transport in chloroplasts, have been reviewed. Further perspectives on the application of these methods to solve some fundamental and practical problems of membrane bioenergetics are discussed.
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Affiliation(s)
- Alexey Yu. Semenov
- A.N. Belozersky Institute of Physical-Chemical Biology, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia;
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6
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Niu Y, Lazár D, Holzwarth AR, Kramer DM, Matsubara S, Fiorani F, Poorter H, Schrey SD, Nedbal L. Plants cope with fluctuating light by frequency-dependent nonphotochemical quenching and cyclic electron transport. THE NEW PHYTOLOGIST 2023. [PMID: 37429324 DOI: 10.1111/nph.19083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 05/16/2023] [Indexed: 07/12/2023]
Abstract
In natural environments, plants are exposed to rapidly changing light. Maintaining photosynthetic efficiency while avoiding photodamage requires equally rapid regulation of photoprotective mechanisms. We asked what the operation frequency range of regulation is in which plants can efficiently respond to varying light. Chlorophyll fluorescence, P700, plastocyanin, and ferredoxin responses of wild-types Arabidopsis thaliana were measured in oscillating light of various frequencies. We also investigated the npq1 mutant lacking violaxanthin de-epoxidase, the npq4 mutant lacking PsbS protein, and the mutants crr2-2, and pgrl1ab impaired in different pathways of the cyclic electron transport. The fastest was the PsbS-regulation responding to oscillation periods longer than 10 s. Processes involving violaxanthin de-epoxidase dampened changes in chlorophyll fluorescence in oscillation periods of 2 min or longer. Knocking out the PGR5/PGRL1 pathway strongly reduced variations of all monitored parameters, probably due to congestion in the electron transport. Incapacitating the NDH-like pathway only slightly changed the photosynthetic dynamics. Our observations are consistent with the hypothesis that nonphotochemical quenching in slow light oscillations involves violaxanthin de-epoxidase to produce, presumably, a largely stationary level of zeaxanthin. We interpret the observed dynamics of photosystem I components as being formed in slow light oscillations partially by thylakoid remodeling that modulates the redox rates.
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Affiliation(s)
- Yuxi Niu
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
| | - Dušan Lazár
- Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Alfred R Holzwarth
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1105, NL-1081 HV, Amsterdam, the Netherlands
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Shizue Matsubara
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
| | - Fabio Fiorani
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
| | - Hendrik Poorter
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Silvia D Schrey
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
| | - Ladislav Nedbal
- Institute of Bio- and Geosciences/Plant Sciences, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, D-52428, Jülich, Germany
- Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
- PASTEUR, Department of Chemistry, École Normale Supérieure, Université PSL, Sorbonne Université, CNRS, 24, rue Lhomond, 75005, Paris, France
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7
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Degen GE, Jackson PJ, Proctor MS, Zoulias N, Casson SA, Johnson MP. High cyclic electron transfer via the PGR5 pathway in the absence of photosynthetic control. PLANT PHYSIOLOGY 2023; 192:370-386. [PMID: 36774530 PMCID: PMC10152662 DOI: 10.1093/plphys/kiad084] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 01/24/2023] [Indexed: 05/03/2023]
Abstract
The light reactions of photosynthesis couple electron and proton transfers across the thylakoid membrane, generating NADPH, and proton motive force (pmf) that powers the endergonic synthesis of ATP by ATP synthase. ATP and NADPH are required for CO2 fixation into carbohydrates by the Calvin-Benson-Bassham cycle. The dominant ΔpH component of the pmf also plays a photoprotective role in regulating photosystem II light harvesting efficiency through nonphotochemical quenching (NPQ) and photosynthetic control via electron transfer from cytochrome b6f (cytb6f) to photosystem I. ΔpH can be adjusted by increasing the proton influx into the thylakoid lumen via upregulation of cyclic electron transfer (CET) or decreasing proton efflux via downregulation of ATP synthase conductivity (gH+). The interplay and relative contributions of these two elements of ΔpH control to photoprotection are not well understood. Here, we showed that an Arabidopsis (Arabidopsis thaliana) ATP synthase mutant hunger for oxygen in photosynthetic transfer reaction 2 (hope2) with 40% higher proton efflux has supercharged CET. Double crosses of hope2 with the CET-deficient proton gradient regulation 5 and ndh-like photosynthetic complex I lines revealed that PROTON GRADIENT REGULATION 5 (PGR5)-dependent CET is the major pathway contributing to higher proton influx. PGR5-dependent CET allowed hope2 to maintain wild-type levels of ΔpH, CO2 fixation and NPQ, however photosynthetic control remained absent and PSI was prone to photoinhibition. Therefore, high CET in the absence of ATP synthase regulation is insufficient for PSI photoprotection.
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Affiliation(s)
- Gustaf E Degen
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Philip J Jackson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 4NL, UK
| | - Matthew S Proctor
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Nicholas Zoulias
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Stuart A Casson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Matthew P Johnson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
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8
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Yang MH, Lu YS, Ho TC, Shen DHY, Huang YF, Chuang KP, Yuan CH, Tyan YC. Utilizing Proteomic Approach to Analyze Potential Antioxidant Proteins in Plant against Irradiation. Antioxidants (Basel) 2022; 11:antiox11122498. [PMID: 36552706 PMCID: PMC9774815 DOI: 10.3390/antiox11122498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/08/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Gamma-ray irradiation is an effective and clean method of sterilization by inactivating microorganisms. It can also be applied to induce anti-oxidants for future application. In this study, the mung bean (Vigna radiata) was exposed to gamma-ray irradiation under the dose of 0, 5 or 10 kGy. With increasing irradiation doses, the concentrations of malondiadehyde decreased while the levels of total flavonoids and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity increased. It has been shown that consuming flavonoids can provide protective effects. In addition, proteomic analysis identified several proteins having anti-oxidant activities in the 5 kGy irradiated group. These proteins are Apocytochrome f, Systemin receptor SR 160, DELLA protein DWARF8, DEAD-box ATP-dependent RNA helicase 9, ζ-carotene desaturase (ZDS), and Floral homeotic protein AGAMOUS. Our findings indicate that plants contain a variety of phytochemicals and antioxidant proteins which may effectively prevent oxidative stress caused by irradiated peroxidation.
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Affiliation(s)
- Ming-Hui Yang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
- Center of General Education, Shu-Zen Junior College of Medicine and Management, Kaohsiung 821, Taiwan
| | - Yi-Shan Lu
- Office of Safety, Health and Environment, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Tzu-Chuan Ho
- Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Daniel Hueng-Yuan Shen
- Department of Nuclear Medicine, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
| | - Ying-Fong Huang
- Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Nuclear Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
| | - Kuo-Pin Chuang
- Graduate Institute of Animal Vaccine Technology, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan
| | - Cheng-Hui Yuan
- Mass Spectrometry Laboratory, Department of Chemistry, National University of Singapore, Singapore 119077, Singapore
| | - Yu-Chang Tyan
- Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Nuclear Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
- Graduate Institute of Animal Vaccine Technology, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan
- School of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
- Center for Cancer Research, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Research Center for Precision Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Correspondence:
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9
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Zhou L, Gao S, Yang W, Wu S, Huan L, Xie X, Wang X, Lin S, Wang G. Transcriptomic and metabolic signatures of diatom plasticity to light fluctuations. PLANT PHYSIOLOGY 2022; 190:2295-2314. [PMID: 36149329 PMCID: PMC9706478 DOI: 10.1093/plphys/kiac455] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/09/2022] [Indexed: 06/01/2023]
Abstract
Unlike in terrestrial and freshwater ecosystems, light fields in oceans fluctuate due to both horizontal current and vertical mixing. Diatoms thrive and dominate the phytoplankton community in these fluctuating light fields. However, the molecular mechanisms that regulate diatom acclimation and adaptation to light fluctuations are poorly understood. Here, we performed transcriptome sequencing, metabolome profiling, and 13C-tracer labeling on the model diatom Phaeodactylum tricornutum. The diatom acclimated to constant light conditions was transferred to six different light conditions, including constant light (CL5d), short-term (1 h) high light (sHL1h), and short-term (1 h) and long-term (5 days) mild or severe light fluctuation conditions (mFL1h, sFL1h, mFL5d, and sFL5d) that mimicked land and ocean light levels. We identified 2,673 transcripts (25% of the total expressed genes) expressed differentially under different fluctuating light regimes. We also identified 497 transcription factors, 228 not reported previously, which exhibited higher expression under light fluctuations, including 7 with a light-sensitive PAS domain (Per-period circadian protein, Arnt-aryl hydrocarbon receptor nuclear translocator protein, Sim-single-minded protein) and 10 predicted to regulate genes related to light-harvesting complex proteins. Our data showed that prolonged preconditioning in severe light fluctuation enhanced photosynthesis in P. tricornutum under this condition, as evidenced by increased oxygen evolution accompanied by the upregulation of Rubisco and light-harvesting proteins. Furthermore, severe light fluctuation diverted the metabolic flux of assimilated carbon preferentially toward fatty acid storage over sugar and protein. Our results suggest that P. tricornutum use a series of complex and different responsive schemes in photosynthesis and carbon metabolism to optimize their growth under mild and severe light fluctuations. These insights underscore the importance of using more intense conditions when investigating the resilience of phytoplankton to light fluctuations.
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Affiliation(s)
- Lu Zhou
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shan Gao
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Wenting Yang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Songcui Wu
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Li Huan
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xiujun Xie
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xulei Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, Connecticut, USA
| | - Guangce Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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10
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Furutani R, Ohnishi M, Mori Y, Wada S, Miyake C. The difficulty of estimating the electron transport rate at photosystem I. JOURNAL OF PLANT RESEARCH 2022; 135:565-577. [PMID: 34778922 DOI: 10.1007/s10265-021-01357-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
It is still a controversial issue how the electron transport reaction is carried out around photosystem I (PSI) in the photosynthetic electron transport chain. The measurable component in PSI is the oxidized P700, the reaction center chlorophyll in PSI, as the absorbance changes at 820-830 nm. Previously, the quantum yield at PSI [Y(I)] has been estimated as the existence probability of the photo-oxidizable P700 by applying the saturated-pulse illumination (SP; 10,000-20,000 µmol photons m-2 s-1). The electron transport rate (ETR) at PSI has been estimated from the Y(I) value, which was larger than the reaction rate at PSII, evaluated as the quantum yield of PSII, especially under stress-conditions such as CO2-limited and high light intensity conditions. Therefore, it has been considered that the extra electron flow at PSI was enhanced at the stress condition and played an important role in dealing with the excessive light energy. However, some pieces of evidence were reported that the excessive electron flow at PSI would be ignorable from other aspects. In the present research, we confirmed that the Y(I) value estimated by the SP method could be easily misestimated by the limitation of the electron donation to PSI. Moreover, we estimated the quantitative turnover rate of P700+ by the light-to-dark transition. However, the turnover rate of P700 was much slower than the ETR at PSII. It is still hard to quantitatively estimate the ETR at PSI by the current techniques.
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Affiliation(s)
- Riu Furutani
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo, 102-0076, Japan
| | - Miho Ohnishi
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo, 102-0076, Japan
| | - Yuki Mori
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Shinya Wada
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo, 102-0076, Japan
| | - Chikahiro Miyake
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo, 102-0076, Japan.
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11
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Rodriguez-Heredia M, Saccon F, Wilson S, Finazzi G, Ruban AV, Hanke GT. Protection of photosystem I during sudden light stress depends on ferredoxin:NADP(H) reductase abundance and interactions. PLANT PHYSIOLOGY 2022; 188:1028-1042. [PMID: 35060611 PMCID: PMC8825262 DOI: 10.1093/plphys/kiab550] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/29/2021] [Indexed: 06/14/2023]
Abstract
Plant tolerance to high light and oxidative stress is increased by overexpression of the photosynthetic enzyme Ferredoxin:NADP(H) reductase (FNR), but the specific mechanism of FNR-mediated protection remains enigmatic. It has also been reported that the localization of this enzyme within the chloroplast is related to its role in stress tolerance. Here, we dissected the impact of FNR content and location on photoinactivation of photosystem I (PSI) and photosystem II (PSII) during high light stress of Arabidopsis (Arabidopsis thaliana). The reaction center of PSII is efficiently turned over during light stress, while damage to PSI takes much longer to repair. Our results indicate a PSI sepcific effect, where efficient oxidation of the PSI primary donor (P700) upon transition from darkness to light, depends on FNR recruitment to the thylakoid membrane tether proteins: thylakoid rhodanase-like protein (TROL) and translocon at the inner envelope of chloroplasts 62 (Tic62). When these interactions were disrupted, PSI photoinactivation occurred. In contrast, there was a moderate delay in the onset of PSII damage. Based on measurements of ΔpH formation and cyclic electron flow, we propose that FNR location influences the speed at which photosynthetic control is induced, resulting in specific impact on PSI damage. Membrane tethering of FNR therefore plays a role in alleviating high light stress, by regulating electron distribution during short-term responses to light.
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Affiliation(s)
| | - Francesco Saccon
- Department of Biochemistry, Queen Mary University of London, London E1 4NS, UK
| | - Sam Wilson
- Department of Biochemistry, Queen Mary University of London, London E1 4NS, UK
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Université Grenoble Alpes, Institut National de Recherche Agronomique (INRA), Institut de Recherche en Sciences et Technologies pour le Vivant (iRTSV), CEA Grenoble, F-38054 Grenoble cedex 9, France
| | - Alexander V Ruban
- Department of Biochemistry, Queen Mary University of London, London E1 4NS, UK
| | - Guy T Hanke
- Department of Biochemistry, Queen Mary University of London, London E1 4NS, UK
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12
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Wilson S, Johnson MP, Ruban AV. Proton motive force in plant photosynthesis dominated by ΔpH in both low and high light. PLANT PHYSIOLOGY 2021; 187:263-275. [PMID: 34618143 PMCID: PMC8418402 DOI: 10.1093/plphys/kiab270] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/23/2021] [Indexed: 05/08/2023]
Abstract
The proton motive force (pmf) across the thylakoid membrane couples photosynthetic electron transport and ATP synthesis. In recent years, the electrochromic carotenoid and chlorophyll absorption band shift (ECS), peaking ∼515 nm, has become a widely used probe to measure pmf in leaves. However, the use of this technique to calculate the parsing of the pmf between the proton gradient (ΔpH) and electric potential (Δψ) components remains controversial. Interpretation of the ECS signal is complicated by overlapping absorption changes associated with violaxanthin de-epoxidation to zeaxanthin (ΔA505) and energy-dependent nonphotochemical quenching (qE; ΔA535). In this study, we used Arabidopsis (Arabidopsis thaliana) plants with altered xanthophyll cycle activity and photosystem II subunit S (PsbS) content to disentangle these overlapping contributions. In plants where overlap among ΔA505, ΔA535, and ECS is diminished, such as npq4 (lacking ΔA535) and npq1npq4 (also lacking ΔA505), the parsing method implies the Δψ contribution is virtually absent and pmf is solely composed of ΔpH. Conversely, in plants where ΔA535 and ECS overlap is enhanced, such as L17 (a PsbS overexpressor) and npq1 (where ΔA535 is blue-shifted to 525 nm) the parsing method implies a dominant contribution of Δψ to the total pmf. These results demonstrate the vast majority of the pmf attributed by the ECS parsing method to Δψ is caused by ΔA505 and ΔA535 overlap, confirming pmf is dominated by ΔpH following the first 60 s of continuous illumination under both low and high light conditions. Further implications of these findings for the regulation of photosynthesis are discussed.
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Affiliation(s)
- Sam Wilson
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Matthew P. Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Alexander V. Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
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13
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Dobson Z, Ahad S, Vanlandingham J, Toporik H, Vaughn N, Vaughn M, Williams D, Reppert M, Fromme P, Mazor Y. The structure of photosystem I from a high-light-tolerant cyanobacteria. eLife 2021; 10:e67518. [PMID: 34435952 PMCID: PMC8428864 DOI: 10.7554/elife.67518] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 08/25/2021] [Indexed: 12/22/2022] Open
Abstract
Photosynthetic organisms have adapted to survive a myriad of extreme environments from the earth's deserts to its poles, yet the proteins that carry out the light reactions of photosynthesis are highly conserved from the cyanobacteria to modern day crops. To investigate adaptations of the photosynthetic machinery in cyanobacteria to excessive light stress, we isolated a new strain of cyanobacteria, Cyanobacterium aponinum 0216, from the extreme light environment of the Sonoran Desert. Here we report the biochemical characterization and the 2.7 Å resolution structure of trimeric photosystem I from this high-light-tolerant cyanobacterium. The structure shows a new conformation of the PsaL C-terminus that supports trimer formation of cyanobacterial photosystem I. The spectroscopic analysis of this photosystem I revealed a decrease in far-red absorption, which is attributed to a decrease in the number of long- wavelength chlorophylls. Using these findings, we constructed two chimeric PSIs in Synechocystis sp. PCC 6803 demonstrating how unique structural features in photosynthetic complexes can change spectroscopic properties, allowing organisms to thrive under different environmental stresses.
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Affiliation(s)
- Zachary Dobson
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Safa Ahad
- Department of Chemistry, Purdue UniversityWest LafayetteUnited States
| | - Jackson Vanlandingham
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Hila Toporik
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Natalie Vaughn
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Michael Vaughn
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Dewight Williams
- John M. Cowley Center for High Resolution Electron Microscopy, Arizona State UniversityTempeUnited States
| | - Michael Reppert
- Department of Chemistry, Purdue UniversityWest LafayetteUnited States
| | - Petra Fromme
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Yuval Mazor
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
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14
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Haber Z, Lampl N, Meyer AJ, Zelinger E, Hipsch M, Rosenwasser S. Resolving diurnal dynamics of the chloroplastic glutathione redox state in Arabidopsis reveals its photosynthetically derived oxidation. THE PLANT CELL 2021; 33:1828-1844. [PMID: 33624811 PMCID: PMC8254480 DOI: 10.1093/plcell/koab068] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 02/23/2021] [Indexed: 05/05/2023]
Abstract
Plants are subjected to fluctuations in light intensity, and this might cause unbalanced photosynthetic electron fluxes and overproduction of reactive oxygen species (ROS). Electrons needed for ROS detoxification are drawn, at least partially, from the cellular glutathione (GSH) pool via the ascorbate-glutathione cycle. Here, we explore the dynamics of the chloroplastic glutathione redox potential (chl-EGSH) using high-temporal-resolution monitoring of Arabidopsis (Arabidopsis thaliana) lines expressing the reduction-oxidation sensitive green fluorescent protein 2 (roGFP2) in chloroplasts. This was carried out over several days under dynamic environmental conditions and in correlation with PSII operating efficiency. Peaks in chl-EGSH oxidation during dark-to-light and light-to-dark transitions were observed. Increasing light intensities triggered a binary oxidation response, with a threshold around the light saturating point, suggesting two regulated oxidative states of the chl-EGSH. These patterns were not affected in npq1 plants, which are impaired in non-photochemical quenching. Oscillations between the two oxidation states were observed under fluctuating light in WT and npq1 plants, but not in pgr5 plants, suggesting a role for PSI photoinhibition in regulating the chl-EGSH dynamics. Remarkably, pgr5 plants showed an increase in chl-EGSH oxidation during the nights following light stresses, linking daytime photoinhibition and nighttime GSH metabolism. This work provides a systematic view of the dynamics of the in vivo chloroplastic glutathione redox state during varying light conditions.
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Affiliation(s)
- Zechariah Haber
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture,
The Hebrew University of Jerusalem, Rehovot 7610000, Israel
| | - Nardy Lampl
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture,
The Hebrew University of Jerusalem, Rehovot 7610000, Israel
| | - Andreas J Meyer
- Institute of Crop Science and Resource Conservation (INRES), Rheinische
Friedrich–Wilhelms Universität Bonn, Friedrich-Ebert-Allee 144, D-53113
Bonn, Germany
| | - Einat Zelinger
- The Interdepartmental Equipment Unit, The Robert H. Smith Faculty of
Agriculture, Food and Environment, The Hebrew University of Jerusalem,
Rehovot 7610001, Israel
| | - Matanel Hipsch
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture,
The Hebrew University of Jerusalem, Rehovot 7610000, Israel
| | - Shilo Rosenwasser
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture,
The Hebrew University of Jerusalem, Rehovot 7610000, Israel
- Author for correspondence:
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15
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Ohnishi M, Furutani R, Sohtome T, Suzuki T, Wada S, Tanaka S, Ifuku K, Ueno D, Miyake C. Photosynthetic Parameters Show Specific Responses to Essential Mineral Deficiencies. Antioxidants (Basel) 2021; 10:996. [PMID: 34201487 PMCID: PMC8300717 DOI: 10.3390/antiox10070996] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 06/08/2021] [Accepted: 06/18/2021] [Indexed: 11/18/2022] Open
Abstract
In response to decreases in the assimilation efficiency of CO2, plants oxidize the reaction center chlorophyll (P700) of photosystem I (PSI) to suppress reactive oxygen species (ROS) production. In hydro-cultured sunflower leaves experiencing essential mineral deficiencies, we analyzed the following parameters that characterize PSI and PSII: (1) the reduction-oxidation states of P700 [Y(I), Y(NA), and Y(ND)]; (2) the relative electron flux in PSII [Y(II)]; (3) the reduction state of the primary electron acceptor in PSII, QA (1 - qL); and (4) the non-photochemical quenching of chlorophyll fluorescence (NPQ). Deficiency treatments for the minerals N, P, Mn, Mg, S, and Zn decreased Y(II) with an increase in the oxidized P700 [Y(ND)], while deficiencies for the minerals K, Fe, Ca, B, and Mo decreased Y(II) without an increase in Y(ND). During the induction of photosynthesis, the above parameters showed specific responses to each mineral. That is, we could diagnose the mineral deficiency and identify which mineral affected the photosynthesis parameters.
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Affiliation(s)
- Miho Ohnishi
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
| | - Riu Furutani
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
| | - Takayuki Sohtome
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
- Department of System Development, Bunkoukeiki Co. Ltd., 4-8 Takakura-machi, Hachioji-shi, Tokyo 192-0033, Japan
| | - Takeshi Suzuki
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
| | - Shinya Wada
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
| | - Soma Tanaka
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
| | - Kentaro Ifuku
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan;
| | - Daisei Ueno
- Graduate School of Integrated Arts and Science, Kochi University, 200 Otsu, Monobe, Nankoku 783-8502, Japan;
| | - Chikahiro Miyake
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
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16
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Gjindali A, Herrmann HA, Schwartz JM, Johnson GN, Calzadilla PI. A Holistic Approach to Study Photosynthetic Acclimation Responses of Plants to Fluctuating Light. FRONTIERS IN PLANT SCIENCE 2021; 12:668512. [PMID: 33936157 PMCID: PMC8079764 DOI: 10.3389/fpls.2021.668512] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/23/2021] [Indexed: 05/10/2023]
Abstract
Plants in natural environments receive light through sunflecks, the duration and distribution of these being highly variable across the day. Consequently, plants need to adjust their photosynthetic processes to avoid photoinhibition and maximize yield. Changes in the composition of the photosynthetic apparatus in response to sustained changes in the environment are referred to as photosynthetic acclimation, a process that involves changes in protein content and composition. Considering this definition, acclimation differs from regulation, which involves processes that alter the activity of individual proteins over short-time periods, without changing the abundance of those proteins. The interconnection and overlapping of the short- and long-term photosynthetic responses, which can occur simultaneously or/and sequentially over time, make the study of long-term acclimation to fluctuating light in plants challenging. In this review we identify short-term responses of plants to fluctuating light that could act as sensors and signals for acclimation responses, with the aim of understanding how plants integrate environmental fluctuations over time and tailor their responses accordingly. Mathematical modeling has the potential to integrate physiological processes over different timescales and to help disentangle short-term regulatory responses from long-term acclimation responses. We review existing mathematical modeling techniques for studying photosynthetic responses to fluctuating light and propose new methods for addressing the topic from a holistic point of view.
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Affiliation(s)
- Armida Gjindali
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Helena A. Herrmann
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
- Division of Evolution & Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Jean-Marc Schwartz
- Division of Evolution & Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Giles N. Johnson
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Pablo I. Calzadilla
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
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17
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Malone LA, Proctor MS, Hitchcock A, Hunter CN, Johnson MP. Cytochrome b 6f - Orchestrator of photosynthetic electron transfer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148380. [PMID: 33460588 DOI: 10.1016/j.bbabio.2021.148380] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/06/2021] [Accepted: 01/09/2021] [Indexed: 11/18/2022]
Abstract
Cytochrome b6f (cytb6f) lies at the heart of the light-dependent reactions of oxygenic photosynthesis, where it serves as a link between photosystem II (PSII) and photosystem I (PSI) through the oxidation and reduction of the electron carriers plastoquinol (PQH2) and plastocyanin (Pc). A mechanism of electron bifurcation, known as the Q-cycle, couples electron transfer to the generation of a transmembrane proton gradient for ATP synthesis. Cytb6f catalyses the rate-limiting step in linear electron transfer (LET), is pivotal for cyclic electron transfer (CET) and plays a key role as a redox-sensing hub involved in the regulation of light-harvesting, electron transfer and photosynthetic gene expression. Together, these characteristics make cytb6f a judicious target for genetic manipulation to enhance photosynthetic yield, a strategy which already shows promise. In this review we will outline the structure and function of cytb6f with a particular focus on new insights provided by the recent high-resolution map of the complex from Spinach.
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Affiliation(s)
- Lorna A Malone
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Matthew S Proctor
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
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18
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Hepworth C, Wood WHJ, Emrich-Mills TZ, Proctor MS, Casson S, Johnson MP. Dynamic thylakoid stacking and state transitions work synergistically to avoid acceptor-side limitation of photosystem I. NATURE PLANTS 2021. [PMID: 33432159 DOI: 10.1038/s41477-020-00828-823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
TAP38/STN7-dependent (de)phosphorylation of light-harvesting complex II (LHCII) regulates the relative excitation rates of photosystems I and II (PSI, PSII) (state transitions) and the size of the thylakoid grana stacks (dynamic thylakoid stacking). Yet, it remains unclear how changing grana size benefits photosynthesis and whether these two regulatory mechanisms function independently. Here, by comparing Arabidopsis wild-type, stn7 and tap38 plants with the psal mutant, which undergoes dynamic thylakoid stacking but lacks state transitions, we explain their distinct roles. Under low light, smaller grana increase the rate of PSI reduction and photosynthesis by reducing the diffusion distance for plastoquinol; however, this beneficial effect is only apparent when PSI/PSII excitation balance is maintained by state transitions or far-red light. Under high light, the larger grana slow plastoquinol diffusion and lower the equilibrium constant between plastocyanin and PSI, maximizing photosynthesis by avoiding PSI photoinhibition. Loss of state transitions in low light or maintenance of smaller grana in high light also both bring about a decrease in cyclic electron transfer and over-reduction of the PSI acceptor side. These results demonstrate that state transitions and dynamic thylakoid stacking work synergistically to regulate photosynthesis in variable light.
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Affiliation(s)
- Christopher Hepworth
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - William H J Wood
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Tom Z Emrich-Mills
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Matthew S Proctor
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Stuart Casson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK.
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19
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Hepworth C, Wood WHJ, Emrich-Mills TZ, Proctor MS, Casson S, Johnson MP. Dynamic thylakoid stacking and state transitions work synergistically to avoid acceptor-side limitation of photosystem I. NATURE PLANTS 2021; 7:87-98. [PMID: 33432159 DOI: 10.1038/s41477-020-00828-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 12/04/2020] [Indexed: 05/11/2023]
Abstract
TAP38/STN7-dependent (de)phosphorylation of light-harvesting complex II (LHCII) regulates the relative excitation rates of photosystems I and II (PSI, PSII) (state transitions) and the size of the thylakoid grana stacks (dynamic thylakoid stacking). Yet, it remains unclear how changing grana size benefits photosynthesis and whether these two regulatory mechanisms function independently. Here, by comparing Arabidopsis wild-type, stn7 and tap38 plants with the psal mutant, which undergoes dynamic thylakoid stacking but lacks state transitions, we explain their distinct roles. Under low light, smaller grana increase the rate of PSI reduction and photosynthesis by reducing the diffusion distance for plastoquinol; however, this beneficial effect is only apparent when PSI/PSII excitation balance is maintained by state transitions or far-red light. Under high light, the larger grana slow plastoquinol diffusion and lower the equilibrium constant between plastocyanin and PSI, maximizing photosynthesis by avoiding PSI photoinhibition. Loss of state transitions in low light or maintenance of smaller grana in high light also both bring about a decrease in cyclic electron transfer and over-reduction of the PSI acceptor side. These results demonstrate that state transitions and dynamic thylakoid stacking work synergistically to regulate photosynthesis in variable light.
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Affiliation(s)
- Christopher Hepworth
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - William H J Wood
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Tom Z Emrich-Mills
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Matthew S Proctor
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Stuart Casson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, UK.
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20
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Wang C, Shikanai T. Modification of Activity of the Thylakoid H +/K + Antiporter KEA3 Disturbs ∆pH-Dependent Regulation of Photosynthesis. PLANT PHYSIOLOGY 2019; 181:762-773. [PMID: 31427465 PMCID: PMC6776848 DOI: 10.1104/pp.19.00766] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 08/07/2019] [Indexed: 05/19/2023]
Abstract
The thylakoid K+ efflux antiporter 3 (KEA3) is required for regulating components of the proton motive force (pmf), proton concentration gradient (ΔpH), and membrane potential (Δψ). The Arabidopsis (Arabidopsis thaliana) disturbed proton gradient regulation mutant (dpgr) is a dominant allele of KEA3, conferring disturbed transport activity. Here, we show that overexpressing the DPGR-type KEA3 (DPGRox) retarded plant growth, whereas overexpressing the wild-type KEA3 (KEA3ox) did not. In KEA3ox lines, the contribution of Δψ to pmf was enhanced, but in DPGRox lines, the size of pmf was reduced. In DPGRox plants, proton conductivity of the thylakoid membrane (g H +) was elevated under high light, implying disturbed stoichiometry of H+/K+ antiport through DPGR-type KEA3 rather than simply enhanced activity. The ΔpH-dependent regulation consisting of thermal dissipation of excessively absorbed light energy and downregulation of cytochrome b 6 f complex activity was severely and mildly affected in DPGRox and KEA3ox plants, respectively. Consequently, photosystem I was sensitive to fluctuating light in both transgenic plants. Both photosystems were sensitive to constant high light and were slightly photodamaged even at standard growth light intensity in DPGRox plants. KEA3 regulates the components of pmf and optimizes the operation of ∆pH-dependent regulation of electron transport.
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Affiliation(s)
- Caijuan Wang
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
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21
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Trinh MDL, Sato R, Masuda S. Genetic characterization of a flap1 null mutation in Arabidopsis npq4 and pgr5 plants suggests that the regulatory role of FLAP1 involves the control of proton homeostasis in chloroplasts. PHOTOSYNTHESIS RESEARCH 2019; 139:413-424. [PMID: 30390180 DOI: 10.1007/s11120-018-0575-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 08/24/2018] [Indexed: 05/21/2023]
Abstract
Precise control of the proton concentration gradient across thylakoid membranes (ΔpH) is essential for photosynthesis and its regulation because the gradient contributes to the generation of the proton motive force used for ATP synthesis and also for the fast and reversible induction of non-photochemical quenching (NPQ) to avoid photoinhibition and photodamage. However, the regulatory mechanism(s) controlling ΔpH in response to fluctuating light has not been fully elucidated. We previously described a new NPQ-regulatory chloroplastic protein, Fluctuating-Light-Acclimation Protein1 (FLAP1), which is important for plant growth and modulation of ΔpH under fluctuating light conditions. For this report, we further characterized FLAP1 activity by individually crossing an Arabidopsis flap1 mutant with npq4 and pgr5 plants; npq4 is defective in PsbS-dependent NPQ, and pgr5 is defective in induction of steady-state proton motive force (pmf) and energy-dependent quenching (qE). Both npq4 and npq4 flap1 exhibited similar NPQ kinetics and other photosynthetic parameters under constant or fluctuating actinic light. Conversely, pgr5 flap1 had recovered NPQ, photosystem II quantum yield and growth under fluctuating light, each of which was impaired in pgr5. Together with other data, we propose that FLAP1 activity controls proton homeostasis under steady-state photosynthesis to manipulate luminal acidification levels appropriately to balance photoprotection and photochemical processes.
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Affiliation(s)
- Mai Duy Luu Trinh
- Graduate School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Ryoichi Sato
- Graduate School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
| | - Shinji Masuda
- Center for Biological Resources & Informatics, Tokyo Institute of Technology, Yokohama, 226-8501, Japan.
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22
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Yamamoto H, Shikanai T. PGR5-Dependent Cyclic Electron Flow Protects Photosystem I under Fluctuating Light at Donor and Acceptor Sides. PLANT PHYSIOLOGY 2019; 179:588-600. [PMID: 30464024 PMCID: PMC6426425 DOI: 10.1104/pp.18.01343] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 11/12/2018] [Indexed: 05/14/2023]
Abstract
In response to a sudden increase in light intensity, plants must cope with absorbed excess photon energy to protect photosystems from photodamage. Under fluctuating light, PSI is severely photodamaged in the Arabidopsis (Arabidopsis thaliana) proton gradient regulation5 (pgr5) mutant defective in the main pathway of PSI cyclic electron transport (CET). Here, we aimed to determine how PSI is protected by two proposed regulatory roles of CET via transthylakoid ΔpH formation: (1) reservation of electron sink capacity by adjusting the ATP/NADPH production ratio (acceptor-side regulation) and (2) down-regulation of the cytochrome b 6 f complex activity called photosynthetic control for slowing down the electron flow toward PSI (donor-side regulation). We artificially enhanced donor- and acceptor-side regulation in the wild-type and pgr5 backgrounds by introducing the pgr1 mutation conferring the hypersensitivity of the cytochrome b 6 f complex to luminal acidification and moss Physcomitrella patens flavodiiron protein genes, respectively. Enhanced photosynthetic control partially alleviated PSI photodamage in the pgr5 mutant background but restricted linear electron transport under constant high light, suggesting that the strength of photosynthetic control should be optimized. Flavodiiron protein-dependent oxygen photoreduction formed a large electron sink and alleviated PSI photoinhibition, accompanied by the induction of photosynthetic control. Thus, donor-side regulation is essential for PSI photoprotection but acceptor-side regulation also is important to rapidly induce donor-side regulation. In angiosperms, PGR5-dependent CET is required for both functions.
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Affiliation(s)
- Hiroshi Yamamoto
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502 Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502 Japan
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23
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Nikkanen L, Toivola J, Trotta A, Diaz MG, Tikkanen M, Aro E, Rintamäki E. Regulation of cyclic electron flow by chloroplast NADPH-dependent thioredoxin system. PLANT DIRECT 2018; 2:e00093. [PMID: 31245694 PMCID: PMC6508795 DOI: 10.1002/pld3.93] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 09/12/2018] [Accepted: 10/15/2018] [Indexed: 05/18/2023]
Abstract
Linear electron transport in the thylakoid membrane drives photosynthetic NADPH and ATP production, while cyclic electron flow (CEF) around photosystem I only promotes the translocation of protons from stroma to thylakoid lumen. The chloroplast NADH dehydrogenase-like complex (NDH) participates in one CEF route transferring electrons from ferredoxin back to the plastoquinone pool with concomitant proton pumping to the lumen. CEF has been proposed to balance the ratio of ATP/NADPH production and to control the redox poise particularly in fluctuating light conditions, but the mechanisms regulating the NDH complex remain unknown. We have investigated potential regulation of the CEF pathways by the chloroplast NADPH-thioredoxin reductase (NTRC) in vivo by using an Arabidopsis knockout line of NTRC as well as lines overexpressing NTRC. Here, we present biochemical and biophysical evidence showing that NTRC stimulates the activity of NDH-dependent CEF and is involved in the regulation of generation of proton motive force, thylakoid conductivity to protons, and redox balance between the thylakoid electron transfer chain and the stroma during changes in light conditions. Furthermore, protein-protein interaction assays suggest a putative thioredoxin-target site in close proximity to the ferredoxin-binding domain of NDH, thus providing a plausible mechanism for redox regulation of the NDH ferredoxin:plastoquinone oxidoreductase activity.
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Affiliation(s)
- Lauri Nikkanen
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Jouni Toivola
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Andrea Trotta
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Manuel Guinea Diaz
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Mikko Tikkanen
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Eva‐Mari Aro
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
| | - Eevi Rintamäki
- Molecular Plant BiologyDepartment of BiochemistryUniversity of TurkuTurkuFinland
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24
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Davis GA, Rutherford AW, Kramer DM. Hacking the thylakoid proton motive force for improved photosynthesis: modulating ion flux rates that control proton motive force partitioning into Δ ψ and ΔpH. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0381. [PMID: 28808100 DOI: 10.1098/rstb.2016.0381] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2017] [Indexed: 11/12/2022] Open
Abstract
There is considerable interest in improving plant productivity by altering the dynamic responses of photosynthesis in tune with natural conditions. This is exemplified by the 'energy-dependent' form of non-photochemical quenching (qE), the formation and decay of which can be considerably slower than natural light fluctuations, limiting photochemical yield. In addition, we recently reported that rapidly fluctuating light can produce field recombination-induced photodamage (FRIP), where large spikes in electric field across the thylakoid membrane (Δψ) induce photosystem II recombination reactions that produce damaging singlet oxygen (1O2). Both qE and FRIP are directly linked to the thylakoid proton motive force (pmf), and in particular, the slow kinetics of partitioning pmf into its ΔpH and Δψ components. Using a series of computational simulations, we explored the possibility of 'hacking' pmf partitioning as a target for improving photosynthesis. Under a range of illumination conditions, increasing the rate of counter-ion fluxes across the thylakoid membrane should lead to more rapid dissipation of Δψ and formation of ΔpH. This would result in increased rates for the formation and decay of qE while resulting in a more rapid decline in the amplitudes of Δψ-spikes and decreasing 1O2 production. These results suggest that ion fluxes may be a viable target for plant breeding or engineering. However, these changes also induce transient, but substantial mismatches in the ATP : NADPH output ratio as well as in the osmotic balance between the lumen and stroma, either of which may explain why evolution has not already accelerated thylakoid ion fluxes. Overall, though the model is simplified, it recapitulates many of the responses seen in vivo, while spotlighting critical aspects of the complex interactions between pmf components and photosynthetic processes. By making the programme available, we hope to enable the community of photosynthesis researchers to further explore and test specific hypotheses.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.,Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI 48824, USA
| | | | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA .,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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25
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A chloroplast thylakoid lumen protein is required for proper photosynthetic acclimation of plants under fluctuating light environments. Proc Natl Acad Sci U S A 2017; 114:E8110-E8117. [PMID: 28874535 DOI: 10.1073/pnas.1712206114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Despite our increasingly sophisticated understanding of mechanisms ensuring efficient photosynthesis under laboratory-controlled light conditions, less is known about the regulation of photosynthesis under fluctuating light. This is important because-in nature-photosynthetic organisms experience rapid and extreme changes in sunlight, potentially causing deleterious effects on photosynthetic efficiency and productivity. Here we report that the chloroplast thylakoid lumenal protein MAINTENANCE OF PHOTOSYSTEM II UNDER HIGH LIGHT 2 (MPH2; encoded by At4g02530) is required for growth acclimation of Arabidopsis thaliana plants under controlled photoinhibitory light and fluctuating light environments. Evidence is presented that mph2 mutant light stress susceptibility results from a defect in photosystem II (PSII) repair, and our results are consistent with the hypothesis that MPH2 is involved in disassembling monomeric complexes during regeneration of dimeric functional PSII supercomplexes. Moreover, mph2-and previously characterized PSII repair-defective mutants-exhibited reduced growth under fluctuating light conditions, while PSII photoprotection-impaired mutants did not. These findings suggest that repair is not only required for PSII maintenance under static high-irradiance light conditions but is also a regulatory mechanism facilitating photosynthetic adaptation under fluctuating light environments. This work has implications for improvement of agricultural plant productivity through engineering PSII repair.
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26
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Fristedt R, Trotta A, Suorsa M, Nilsson AK, Croce R, Aro EM, Lundin B. PSB33 sustains photosystem II D1 protein under fluctuating light conditions. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4281-4293. [PMID: 28922769 PMCID: PMC5853261 DOI: 10.1093/jxb/erx218] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 06/05/2017] [Indexed: 05/24/2023]
Abstract
On Earth, solar irradiance varies as the sun rises and sets over the horizon, and sunlight is thus in constant fluctuation, following a slow dark-low-high-low-dark curve. Optimal plant growth and development are dependent on the capacity of plants to acclimate and regulate photosynthesis in response to these changes of light. Little is known of regulative processes for photosynthesis during nocturnal events. The nucleus-encoded plant lineage-specific protein PSB33 has been described as stabilizing the photosystem II complex, especially under light stress conditions, and plants lacking PSB33 have a dysfunctional state transition. To clarify the localization and function of this protein, we used phenomic, biochemical and proteomics approaches in the model plant Arabidopsis. We report that PSB33 is predominantly located in non-appressed thylakoid regions and dynamically associates with a thylakoid protein complex in a light-dependent manner. Moreover, plants lacking PSB33 show an accelerated D1 protein degradation in nocturnal periods, and show severely stunted growth when challenged with fluctuating light. We further show that the function of PSB33 precedes the STN7 kinase to regulate or balance the excitation energy of photosystems I and II in fluctuating light conditions.
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Affiliation(s)
- Rikard Fristedt
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan, Amsterdam, The Netherlands
| | - Andrea Trotta
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Finland
| | - Marjaana Suorsa
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Finland
| | - Anders K Nilsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Roberta Croce
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan, Amsterdam, The Netherlands
| | - Eva-Mari Aro
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Finland
| | - Björn Lundin
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
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27
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Armbruster U, Correa Galvis V, Kunz HH, Strand DD. The regulation of the chloroplast proton motive force plays a key role for photosynthesis in fluctuating light. CURRENT OPINION IN PLANT BIOLOGY 2017; 37:56-62. [PMID: 28426975 DOI: 10.1016/j.pbi.2017.03.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/23/2017] [Accepted: 03/24/2017] [Indexed: 05/22/2023]
Abstract
Plants use sunlight as their primary energy source. During photosynthesis, absorbed light energy generates reducing power by driving electron transfer reactions. These are coupled to the transfer of protons into the thylakoid lumen, generating a proton motive force (pmf) required for ATP synthesis. Sudden alterations in light availability have to be met by regulatory mechanisms to avoid the over-accumulation of reactive intermediates and maximize energy efficiency. Here, the acidification of the lumen, as an intermediate product of photosynthesis, plays an important role by regulating photosynthesis in response to excitation energy levels. Recent findings reveal pmf regulation and the modulation of its composition as key determinants for efficient photosynthesis, plant growth, and survival in fluctuating light environments.
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Affiliation(s)
- Ute Armbruster
- Regulation of Photosynthesis Group, Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany.
| | - Viviana Correa Galvis
- Regulation of Photosynthesis Group, Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Hans-Henning Kunz
- Plant Physiology, School of Biological Sciences, Washington State University, P.O. Box 644236, Pullman, WA 99164-4236, USA
| | - Deserah D Strand
- Organelle Biology and Biotechnology Group, Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam, Germany
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28
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Huang W, Yang YJ, Zhang SB. Specific roles of cyclic electron flow around photosystem I in photosynthetic regulation in immature and mature leaves. JOURNAL OF PLANT PHYSIOLOGY 2017; 209:76-83. [PMID: 28013173 DOI: 10.1016/j.jplph.2016.11.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 11/07/2016] [Accepted: 11/16/2016] [Indexed: 05/07/2023]
Abstract
Cyclic electron flow (CEF) around photosystem I (PSI) is essential for photosynthesis in mature leaves. However, the physiological roles of CEF in immature leaves are little known. Here, we measured the PSI and PSII activities, light response changes in PSI and PSII energy quenching for immature and mature leaves of Erythrophleum guineense grown under full sunlight. Comparing with the maximum quantum yield of PSII (Fv/Fm), the immature leaves had much lower values of the maximum photo-oxidizable P700 (Pm) than the mature leaves, suggesting the unsynchronized development of PSI and PSII activities. Furthermore, the immature leaves displayed significantly lower capacities for the photosynthetic electron flow through PSII (ETRII) and CEF. However, when exposed to high light, the immature leaves displayed higher levels of non-photochemical quenching (NPQ) and P700 oxidation ration [Y(ND)] than mature leaves. Under high light, the similar NPQ values were accompanied with much lower CEF activity in the immature leaves. These results suggest that, in immature leaves, CEF primarily contributes to photoprotection for PSI and PSII via acidification of thylakoid lumen. By comparison, in mature leaves, a large fraction of CEF-dependent generation of ΔpH contributes to ATP synthesis and a relative small proportion favors photoprotection via lumen acidification. These findings highlight the specific roles of CEF in photosynthetic regulation in immature and mature leaves.
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Affiliation(s)
- Wei Huang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China; Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.
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29
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Zhang ZS, Jin LQ, Li YT, Tikkanen M, Li QM, Ai XZ, Gao HY. Ultraviolet-B Radiation (UV-B) Relieves Chilling-Light-Induced PSI Photoinhibition And Accelerates The Recovery Of CO 2 Assimilation In Cucumber (Cucumis sativus L.) Leaves. Sci Rep 2016; 6:34455. [PMID: 27686324 PMCID: PMC5043378 DOI: 10.1038/srep34455] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 09/13/2016] [Indexed: 02/08/2023] Open
Abstract
Ultraviolet-B radiation (UV-B) is generally considered to negatively impact the photosynthetic apparatus and plant growth. UV-B damages PSII but does not directly influence PSI. However, PSI and PSII successively drive photosynthetic electron transfer, therefore, the interaction between these systems is unavoidable. So we speculated that UV-B could indirectly affect PSI under chilling-light conditions. To test this hypothesis, the cucumber leaves were illuminated by UV-B prior or during the chilling-light treatment, and the leaves were then transferred to 25 °C and low-light conditions for recovery. The results showed that UV-B decreased the electron transfer to PSI by inactivating the oxygen-evolving complex (OEC), thereby protecting PSI from chilling-light-induced photoinhibition. This effect advantages the recoveries of PSI and CO2 assimilation after chilling-light stress, therefore should minimize the yield loss caused by chilling-light stress. Because sunlight consists of both UV-B and visible light, we suggest that UV-B-induced OEC inactivation is critical for chilling-light-induced PSI photoinhibition in field. Moreover, additional UV-B irradiation is an effective strategy to relieve PSI photoinhibition and yield loss in protected cultivation during winter. This study also demonstrates that minimizing the photoinhibition of PSI rather than that of PSII is essential for the chilling-light tolerance of the plant photosynthetic apparatus.
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Affiliation(s)
- Zi-Shan Zhang
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.,College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China.,College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Li-Qiao Jin
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.,College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Yu-Ting Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.,College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Mikko Tikkanen
- Plant Physiology and Molecular Biology, Department of Biochemistry and Food Chemistry, University of Turku, FIN-20014 Turku, Finland
| | - Qing-Ming Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.,College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China
| | - Xi-Zhen Ai
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.,College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China
| | - Hui-Yuan Gao
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.,College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
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30
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Ermakova M, Huokko T, Richaud P, Bersanini L, Howe CJ, Lea-Smith DJ, Peltier G, Allahverdiyeva Y. Distinguishing the Roles of Thylakoid Respiratory Terminal Oxidases in the Cyanobacterium Synechocystis sp. PCC 6803. PLANT PHYSIOLOGY 2016; 171:1307-19. [PMID: 27208274 PMCID: PMC4902628 DOI: 10.1104/pp.16.00479] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 04/11/2016] [Indexed: 05/03/2023]
Abstract
Various oxygen-utilizing electron sinks, including the soluble flavodiiron proteins (Flv1/3), and the membrane-localized respiratory terminal oxidases (RTOs), cytochrome c oxidase (Cox) and cytochrome bd quinol oxidase (Cyd), are present in the photosynthetic electron transfer chain of Synechocystis sp. PCC 6803. However, the role of individual RTOs and their relative importance compared with other electron sinks are poorly understood, particularly under light. Via membrane inlet mass spectrometry gas exchange, chlorophyll a fluorescence, P700 analysis, and inhibitor treatment of the wild type and various mutants deficient in RTOs, Flv1/3, and photosystem I, we investigated the contribution of these complexes to the alleviation of excess electrons in the photosynthetic chain. To our knowledge, for the first time, we demonstrated the activity of Cyd in oxygen uptake under light, although it was detected only upon inhibition of electron transfer at the cytochrome b6f site and in ∆flv1/3 under fluctuating light conditions, where linear electron transfer was drastically inhibited due to impaired photosystem I activity. Cox is mostly responsible for dark respiration and competes with P700 for electrons under high light. Only the ∆cox/cyd double mutant, but not single mutants, demonstrated a highly reduced plastoquinone pool in darkness and impaired gross oxygen evolution under light, indicating that thylakoid-based RTOs are able to compensate partially for each other. Thus, both electron sinks contribute to the alleviation of excess electrons under illumination: RTOs continue to function under light, operating on slower time ranges and on a limited scale, whereas Flv1/3 responds rapidly as a light-induced component and has greater capacity.
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Affiliation(s)
- Maria Ermakova
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku FI-20014, Finland (M.E., T.H., L.B., Y.A.);Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Cadarache, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Centre National de la Recherche Scientifique, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Aix Marseille Université, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13284 Marseille, France (P.R., G.P.); andDepartment of Biochemistry, University of Cambridge, Cambridge, CB2 1QW United Kingdom (C.J.H., D.J.L.-S.)
| | - Tuomas Huokko
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku FI-20014, Finland (M.E., T.H., L.B., Y.A.);Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Cadarache, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Centre National de la Recherche Scientifique, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Aix Marseille Université, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13284 Marseille, France (P.R., G.P.); andDepartment of Biochemistry, University of Cambridge, Cambridge, CB2 1QW United Kingdom (C.J.H., D.J.L.-S.)
| | - Pierre Richaud
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku FI-20014, Finland (M.E., T.H., L.B., Y.A.);Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Cadarache, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Centre National de la Recherche Scientifique, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Aix Marseille Université, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13284 Marseille, France (P.R., G.P.); andDepartment of Biochemistry, University of Cambridge, Cambridge, CB2 1QW United Kingdom (C.J.H., D.J.L.-S.)
| | - Luca Bersanini
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku FI-20014, Finland (M.E., T.H., L.B., Y.A.);Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Cadarache, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Centre National de la Recherche Scientifique, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Aix Marseille Université, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13284 Marseille, France (P.R., G.P.); andDepartment of Biochemistry, University of Cambridge, Cambridge, CB2 1QW United Kingdom (C.J.H., D.J.L.-S.)
| | - Christopher J Howe
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku FI-20014, Finland (M.E., T.H., L.B., Y.A.);Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Cadarache, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Centre National de la Recherche Scientifique, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Aix Marseille Université, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13284 Marseille, France (P.R., G.P.); andDepartment of Biochemistry, University of Cambridge, Cambridge, CB2 1QW United Kingdom (C.J.H., D.J.L.-S.)
| | - David J Lea-Smith
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku FI-20014, Finland (M.E., T.H., L.B., Y.A.);Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Cadarache, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Centre National de la Recherche Scientifique, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Aix Marseille Université, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13284 Marseille, France (P.R., G.P.); andDepartment of Biochemistry, University of Cambridge, Cambridge, CB2 1QW United Kingdom (C.J.H., D.J.L.-S.)
| | - Gilles Peltier
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku FI-20014, Finland (M.E., T.H., L.B., Y.A.);Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Cadarache, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Centre National de la Recherche Scientifique, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Aix Marseille Université, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13284 Marseille, France (P.R., G.P.); andDepartment of Biochemistry, University of Cambridge, Cambridge, CB2 1QW United Kingdom (C.J.H., D.J.L.-S.)
| | - Yagut Allahverdiyeva
- Laboratory of Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku FI-20014, Finland (M.E., T.H., L.B., Y.A.);Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et de Biotechnologie, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, Cadarache, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Centre National de la Recherche Scientifique, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13108 Saint-Paul-lez-Durance, France (P.R., G.P.);Aix Marseille Université, Biologie Végétale et Microbiologie Environnementales, Unité Mixte de Recherche 7265, F-13284 Marseille, France (P.R., G.P.); andDepartment of Biochemistry, University of Cambridge, Cambridge, CB2 1QW United Kingdom (C.J.H., D.J.L.-S.)
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31
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Tiwari A, Mamedov F, Grieco M, Suorsa M, Jajoo A, Styring S, Tikkanen M, Aro EM. Photodamage of iron-sulphur clusters in photosystem I induces non-photochemical energy dissipation. NATURE PLANTS 2016; 2:16035. [PMID: 27249566 DOI: 10.1038/nplants.2016.35] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 02/22/2016] [Indexed: 05/19/2023]
Abstract
Photosystem I (PSI) uses light energy and electrons supplied by photosystem II (PSII) to reduce NADP(+) to NADPH. PSI is very tolerant of excess light but extremely sensitive to excess electrons from PSII. It has been assumed that PSI is protected from photoinhibition by strict control of the intersystem electron transfer chain (ETC). Here we demonstrate that the iron-sulphur (FeS) clusters of PSI are more sensitive to high light stress than previously anticipated, but PSI with damaged FeS clusters still functions as a non-photochemical photoprotective energy quencher (PSI-NPQ). Upon photoinhibition of PSI, the highly reduced ETC further triggers thylakoid phosphorylation-based mechanisms that increase energy flow towards PSI. It is concluded that the sensitivity of FeS clusters provides an additional photoprotective mechanism that is able to downregulate PSII, based on PSI quenching and protein phosphorylation.
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Affiliation(s)
- Arjun Tiwari
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Michele Grieco
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Marjaana Suorsa
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Anjana Jajoo
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Stenbjörn Styring
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-75120 Uppsala, Sweden
| | - Mikko Tikkanen
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Eva-Mari Aro
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
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32
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Huang W, Yang YJ, Hu H, Zhang SB. Different roles of cyclic electron flow around photosystem I under sub-saturating and saturating light intensities in tobacco leaves. FRONTIERS IN PLANT SCIENCE 2015; 6:923. [PMID: 26579169 PMCID: PMC4621282 DOI: 10.3389/fpls.2015.00923] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/12/2015] [Indexed: 05/03/2023]
Abstract
In higher plants, the generation of proton gradient across the thylakoid membrane (ΔpH) through cyclic electron flow (CEF) has mainly two functions: (1) to generate ATP and balance the ATP/NADPH energy budget, and (2) to protect photosystems I and II against photoinhibition. The intensity of light under which plants are grown alters both CEF activity and the ATP/NADPH demand for primary metabolic processes. However, it is unclear how the role of CEF is affected by the level of irradiance that is applied during the growth and measurement periods. We studied the role of CEF at different light intensities in leaves from sun- and shade-grown plants. At 849 μmol photons m(-2) s(-1), both types of leaves had nearly the same degree of CEF activation. Modeling of the ATP/NADPH demand revealed that, at this light intensity, the contribution of CEF toward supplying ATP was much higher in the sun leaves. Meanwhile, the shade leaves showed higher levels of non-photochemical quenching and the P700 oxidation ratio. Therefore, at 849 μmol photons m(-2) s(-1), CEF mainly helped in the synthesis of ATP in the sun leaves, but functioned in photoprotection for the shade leaves. When the light intensity increased to 1976 μmol photons m(-2) s(-1), CEF activation was greatly enhanced in the sun leaves, but its contribution to supplying ATP changed slightly. These results indicate that the main role of CEF is altered flexibly in response to light intensity. In particular, CEF mainly contributes to balancing the ATP/NADPH energy budget under sub-saturating light intensities. When exposed to saturating light intensities, CEF mainly protects photosynthetic apparatus against photoinhibition.
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Affiliation(s)
- Wei Huang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of SciencesKunming, China
- Yunnan Key Laboratory for Wild Plant ResourcesKunming, China
| | - Ying-Jie Yang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of SciencesKunming, China
- Yunnan Key Laboratory for Wild Plant ResourcesKunming, China
| | - Hong Hu
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of SciencesKunming, China
- Yunnan Key Laboratory for Wild Plant ResourcesKunming, China
| | - Shi-Bao Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of SciencesKunming, China
- Yunnan Key Laboratory for Wild Plant ResourcesKunming, China
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33
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Huang W, Yang YJ, Hu H, Zhang SB. Different roles of cyclic electron flow around photosystem I under sub-saturating and saturating light intensities in tobacco leaves. FRONTIERS IN PLANT SCIENCE 2015; 6:923. [PMID: 26579169 DOI: 10.3389/fpls.015.00923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/12/2015] [Indexed: 05/25/2023]
Abstract
In higher plants, the generation of proton gradient across the thylakoid membrane (ΔpH) through cyclic electron flow (CEF) has mainly two functions: (1) to generate ATP and balance the ATP/NADPH energy budget, and (2) to protect photosystems I and II against photoinhibition. The intensity of light under which plants are grown alters both CEF activity and the ATP/NADPH demand for primary metabolic processes. However, it is unclear how the role of CEF is affected by the level of irradiance that is applied during the growth and measurement periods. We studied the role of CEF at different light intensities in leaves from sun- and shade-grown plants. At 849 μmol photons m(-2) s(-1), both types of leaves had nearly the same degree of CEF activation. Modeling of the ATP/NADPH demand revealed that, at this light intensity, the contribution of CEF toward supplying ATP was much higher in the sun leaves. Meanwhile, the shade leaves showed higher levels of non-photochemical quenching and the P700 oxidation ratio. Therefore, at 849 μmol photons m(-2) s(-1), CEF mainly helped in the synthesis of ATP in the sun leaves, but functioned in photoprotection for the shade leaves. When the light intensity increased to 1976 μmol photons m(-2) s(-1), CEF activation was greatly enhanced in the sun leaves, but its contribution to supplying ATP changed slightly. These results indicate that the main role of CEF is altered flexibly in response to light intensity. In particular, CEF mainly contributes to balancing the ATP/NADPH energy budget under sub-saturating light intensities. When exposed to saturating light intensities, CEF mainly protects photosynthetic apparatus against photoinhibition.
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Affiliation(s)
- Wei Huang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences Kunming, China ; Yunnan Key Laboratory for Wild Plant Resources Kunming, China
| | - Ying-Jie Yang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences Kunming, China ; Yunnan Key Laboratory for Wild Plant Resources Kunming, China
| | - Hong Hu
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences Kunming, China ; Yunnan Key Laboratory for Wild Plant Resources Kunming, China
| | - Shi-Bao Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences Kunming, China ; Yunnan Key Laboratory for Wild Plant Resources Kunming, China
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34
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Suorsa M. Cyclic electron flow provides acclimatory plasticity for the photosynthetic machinery under various environmental conditions and developmental stages. FRONTIERS IN PLANT SCIENCE 2015; 6:800. [PMID: 26442093 PMCID: PMC4585005 DOI: 10.3389/fpls.2015.00800] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 09/14/2015] [Indexed: 05/03/2023]
Abstract
Photosynthetic electron flow operates in two modes, linear and cyclic. In cyclic electron flow (CEF), electrons are recycled around photosystem I. As a result, a transthylakoid proton gradient (ΔpH) is generated, leading to the production of ATP without concomitant production of NADPH, thus increasing the ATP/NADPH ratio within the chloroplast. At least two routes for CEF exist: a PROTON GRADIENT REGULATION5-PGRL1-and a chloroplast NDH-like complex mediated pathway. This review focuses on recent findings concerning the characteristics of both CEF routes in higher plants, with special emphasis paid on the crucial role of CEF in under challenging environmental conditions and developmental stages.
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Affiliation(s)
- Marjaana Suorsa
- Molecular Plant Biology, Department of Biochemistry, University of TurkuTurku, Finland
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35
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Järvi S, Gollan PJ, Aro EM. Understanding the roles of the thylakoid lumen in photosynthesis regulation. FRONTIERS IN PLANT SCIENCE 2013; 4:434. [PMID: 24198822 PMCID: PMC3813922 DOI: 10.3389/fpls.2013.00434] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/12/2013] [Indexed: 05/20/2023]
Abstract
It has been known for a long time that the thylakoid lumen provides the environment for oxygen evolution, plastocyanin-mediated electron transfer, and photoprotection. More recently lumenal proteins have been revealed to play roles in numerous processes, most often linked with regulating thylakoid biogenesis and the activity and turnover of photosynthetic protein complexes, especially the photosystem II and NAD(P)H dehydrogenase-like complexes. Still, the functions of the majority of lumenal proteins in Arabidopsis thaliana are unknown. Interestingly, while the thylakoid lumen proteome of at least 80 proteins contains several large protein families, individual members of many protein families have highly divergent roles. This is indicative of evolutionary pressure leading to neofunctionalization of lumenal proteins, emphasizing the important role of the thylakoid lumen for photosynthetic electron transfer and ultimately for plant fitness. Furthermore, the involvement of anterograde and retrograde signaling networks that regulate the expression and activity of lumen proteins is increasingly pertinent. Recent studies have also highlighted the importance of thiol/disulfide modulation in controlling the functions of many lumenal proteins and photosynthetic regulation pathways.
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Affiliation(s)
| | | | - Eva-Mari Aro
- *Correspondence: Eva-Mari Aro, Molecular Plant Biology, Department of Biochemistry, University of Turku, FIN-20014 Turku, Finland e-mail:
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