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Shi T, Fan D, Xu C, Zheng G, Zhong C, Feng F, Chow WS. The Fitting of the OJ Phase of Chlorophyll Fluorescence Induction Based on an Analytical Solution and Its Application in Urban Heat Island Research. PLANTS (BASEL, SWITZERLAND) 2024; 13:452. [PMID: 38337985 PMCID: PMC10857409 DOI: 10.3390/plants13030452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/28/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
Chlorophyll (Chl) fluorescence induction (FI) upon a dark-light transition has been widely analyzed to derive information on initial events of energy conversion and electron transfer in photosystem II (PSII). However, currently, there is no analytical solution to the differential equation of QA reduction kinetics, raising a doubt about the fitting of FI by numerical iteration solution. We derived an analytical solution to fit the OJ phase of FI, thereby yielding estimates of three parameters: the functional absorption cross-section of PSII (σPSII), a probability parameter that describes the connectivity among PSII complexes (p), and the rate coefficient for QA- oxidation (kox). We found that σPSII, p, and kox exhibited dynamic changes during the transition from O to J. We postulated that in high excitation light, some other energy dissipation pathways may vastly outcompete against excitation energy transfer from a closed PSII trap to an open PSII, thereby giving the impression that connectivity seemingly does not exist. We also conducted a case study on the urban heat island effect on the heat stability of PSII using our method and showed that higher-temperature-acclimated leaves had a greater σPSII, lower kox, and a tendency of lower p towards more shade-type characteristics.
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Affiliation(s)
- Tongxin Shi
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China; (T.S.)
| | - Dayong Fan
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China; (T.S.)
| | - Chengyang Xu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China; (T.S.)
| | - Guoming Zheng
- Yi Zong Qi Technology (Beijing) Co., Ltd., Beijing 100095, China
| | - Chuanfei Zhong
- Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100093, China
| | - Fei Feng
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China; (T.S.)
| | - Wah Soon Chow
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT 2601, Australia
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Guirguis A, Yang W, Conlan XA, Kong L, Cahill DM, Wang Y. Boosting Plant Photosynthesis with Carbon Dots: A Critical Review of Performance and Prospects. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2300671. [PMID: 37381636 DOI: 10.1002/smll.202300671] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 05/31/2023] [Indexed: 06/30/2023]
Abstract
Artificially augmented photosynthesis in nano-bionic plants requires tunable nano-antenna structures with physiochemical and optoelectronic properties, as well as unique light conversion capabilities. The use of nanomaterials to promote light capture across photosystems, primarily by carbon dots, has shown promising results in enhancing photosynthesis through tunable uptake, translocation, and biocompatibility. Carbon dots possess the ability to perform both down and up-light conversions, making them effective light promoters for harnessing solar energy beyond visible light wavelengths.This review presents and discusses the recent progress in fabrication, chemistry, and morphology, as well as other properties such as photoluminescence and energy conversion efficiency of nano-antennas based on carbon dots. The performance of artificially boosted photosynthesis is discussed and then correlated with the conversion properties of carbon dots and how they are applied to plant models. The challenges related to the nanomaterial delivery and the performance evaluation practices in modified photosystems, consideration of the reliability of this approach, and the potential avenues for performance improvements through other types of nano-antennas based on alternative nanomaterials are also critically evaluated. It is anticipated that this review will stimulate more high-quality research in plant nano-bionics and provide avenues to enhance photosynthesis for future agricultural applications.
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Affiliation(s)
- Albert Guirguis
- School of Life & Environment Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Wenrong Yang
- School of Life & Environment Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Xavier A Conlan
- School of Life & Environment Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Lingxue Kong
- Institute for Frontier Materials, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - David M Cahill
- School of Life & Environment Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Yichao Wang
- School of Life & Environment Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
- School of Engineering, Design and Built Environment, Western Sydney University, Penrith, NSW, 2751, Australia
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Verhoeven D, van Amerongen H, Wientjes E. Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions. PLANT PHYSIOLOGY 2023; 191:1186-1198. [PMID: 36478277 PMCID: PMC9922397 DOI: 10.1093/plphys/kiac561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 11/04/2022] [Indexed: 06/17/2023]
Abstract
Oxygenic photosynthesis is driven by light absorption in photosystem I (PSI) and photosystem II (PSII). A balanced excitation pressure between PSI and PSII is required for optimal photosynthetic efficiency. State transitions serve to keep this balance. If PSII is overexcited in plants and green algae, a mobile pool of light-harvesting complex II (LHCII) associates with PSI, increasing its absorption cross-section and restoring the excitation balance. This is called state 2. Upon PSI overexcitation, this LHCII pool moves to PSII, leading to state 1. Whether the association/dissociation of LHCII with the photosystems occurs between thylakoid grana and thylakoid stroma lamellae during state transitions or within the same thylakoid region remains unclear. Furthermore, although state transitions are thought to be accompanied by changes in thylakoid macro-organization, this has never been observed directly in functional leaves. In this work, we used confocal fluorescence lifetime imaging to quantify state transitions in single Arabidopsis (Arabidopsis thaliana) chloroplasts in folio with sub-micrometer spatial resolution. The change in excitation-energy distribution between PSI and PSII was investigated at a range of excitation wavelengths between 475 and 665 nm. For all excitation wavelengths, the PSI/(PSI + PSII) excitation ratio was higher in state 2 than in state 1. We next imaged the local PSI/(PSI + PSII) excitation ratio for single chloroplasts in both states. The data indicated that LHCII indeed migrates between the grana and stroma lamellae during state transitions. Finally, fluorescence intensity images revealed that thylakoid macro-organization is largely unaffected by state transitions. This single chloroplast in folio imaging method will help in understanding how plants adjust their photosynthetic machinery to ever-changing light conditions.
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Bos PR, Schiphorst C, Kercher I, Buis S, de Jong D, Vunderink I, Wientjes E. Spectral diversity of photosystem I from flowering plants. PHOTOSYNTHESIS RESEARCH 2023; 155:35-47. [PMID: 36260271 PMCID: PMC9792416 DOI: 10.1007/s11120-022-00971-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Photosystem I and II (PSI and PSII) work together to convert solar energy into chemical energy. Whilst a lot of research has been done to unravel variability of PSII fluorescence in response to biotic and abiotic factors, the contribution of PSI to in vivo fluorescence measurements has often been neglected or considered to be constant. Furthermore, little is known about how the absorption and emission properties of PSI from different plant species differ. In this study, we have isolated PSI from five plant species and compared their characteristics using a combination of optical and biochemical techniques. Differences have been identified in the fluorescence emission spectra and at the protein level, whereas the absorption spectra were virtually the same in all cases. In addition, the emission spectrum of PSI depends on temperature over a physiologically relevant range from 280 to 298 K. Combined, our data show a critical comparison of the absorption and emission properties of PSI from various plant species.
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Affiliation(s)
- Peter R Bos
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Christo Schiphorst
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Ian Kercher
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Sieka Buis
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Djanick de Jong
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Igor Vunderink
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands.
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Zamora RA, López-Ortiz M, Sales-Mateo M, Hu C, Croce R, Maniyara RA, Pruneri V, Giannotti MI, Gorostiza P. Light- and Redox-Dependent Force Spectroscopy Reveals that the Interaction between Plastocyanin and Plant Photosystem I Is Favored when One Partner Is Ready for Electron Transfer. ACS NANO 2022; 16:15155-15164. [PMID: 36067071 DOI: 10.1021/acsnano.2c06454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Photosynthesis is a fundamental process that converts photons into chemical energy, driven by large protein complexes at the thylakoid membranes of plants, cyanobacteria, and algae. In plants, water-soluble plastocyanin (Pc) is responsible for shuttling electrons between cytochrome b6f complex and the photosystem I (PSI) complex in the photosynthetic electron transport chain (PETC). For an efficient turnover, a transient complex must form between PSI and Pc in the PETC, which implies a balance between specificity and binding strength. Here, we studied the binding frequency and the unbinding force between suitably oriented plant PSI and Pc under redox control using single molecule force spectroscopy (SMFS). The binding frequency (observation of binding-unbinding events) between PSI and Pc depends on their respective redox states. The interaction between PSI and Pc is independent of the redox state of PSI when Pc is reduced, and it is disfavored in the dark (reduced P700) when Pc is oxidized. The frequency of interaction between PSI and Pc is higher when at least one of the partners is in a redox state ready for electron transfer (ET), and the post-ET situation (PSIRed-PcOx) leads to lower binding. In addition, we show that the binding of ET-ready PcRed to PSI can be regulated externally by Mg2+ ions in solution.
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Affiliation(s)
- Ricardo A Zamora
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
- CIBER-BBN, ISCIII, Barcelona 08028, Spain
| | - Manuel López-Ortiz
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
- CIBER-BBN, ISCIII, Barcelona 08028, Spain
| | - Montserrat Sales-Mateo
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
| | - Chen Hu
- Biophysics of Photosynthesis. Dep. Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis. Dep. Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Rinu Abraham Maniyara
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels 08860, Spain
| | - Valerio Pruneri
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels 08860, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona 08010, Spain
| | - Marina I Giannotti
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
- CIBER-BBN, ISCIII, Barcelona 08028, Spain
- Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 10, Barcelona 08028, Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
- CIBER-BBN, ISCIII, Barcelona 08028, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona 08010, Spain
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6
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Fang Y, Liu D, Jiang J, He A, Zhu R, Tian L. Photoprotective energy quenching in the red alga Porphyridium purpureum occurs at the core antenna of the photosystem II but not at its reaction center. J Biol Chem 2022; 298:101783. [PMID: 35245502 PMCID: PMC8978274 DOI: 10.1016/j.jbc.2022.101783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 01/01/2023] Open
Abstract
Photosynthetic organisms have evolved light-harvesting antennae over time. In cyanobacteria, external phycobilisomes (PBSs) are the dominant antennae, whereas in green algae and higher plants, PBSs have been replaced by proteins of the Lhc family that are integrated in the membrane. Red algae represent an evolutionary intermediate between these two systems, as they employ both PBSs and membrane LHCR proteins as light-harvesting units. Understanding how red algae cope with light is not only interesting for biotechnological applications, but is also of evolutionary interest. For example, energy-dependent quenching (qE) is an essential photoprotective mechanism widely used by species from cyanobacteria to higher plants to avoid light damage; however, the quenching mechanism in red algae remains largely unexplored. Here, we used both pulse amplitude-modulated (PAM) and time-resolved chlorophyll fluorescence to characterize qE kinetics in the red alga Porphyridium purpureum. PAM traces confirmed that qE in P. purpureum is activated by a decrease in the thylakoid lumen pH, whereas time-resolved fluorescence results further revealed the quenching site and ultrafast quenching kinetics. We found that quenching exclusively takes place in the photosystem II (PSII) complexes and preferentially occurs at PSII’s core antenna rather than at its reaction center, with an overall quenching rate of 17.6 ± 3.0 ns−1. In conclusion, we propose that qE in red algae is not a reaction center type of quenching, and that there might be a membrane-bound protein that resembles PsbS of higher plants or LHCSR of green algae that senses low luminal pH and triggers qE in red algae.
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Affiliation(s)
- Yuan Fang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Dongyang Liu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jingjing Jiang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Axin He
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing, China
| | - Rui Zhu
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, China
| | - Lijin Tian
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
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N-doped 2D graphite-2H nanoplatelets (GNPs) with enhanced PMS activation performance: Structure-dependent performance and Catalytic Mechanism. J Taiwan Inst Chem Eng 2022. [DOI: 10.1016/j.jtice.2021.11.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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8
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Caspy I, Neumann E, Fadeeva M, Liveanu V, Savitsky A, Frank A, Kalisman YL, Shkolnisky Y, Murik O, Treves H, Hartmann V, Nowaczyk MM, Schuhmann W, Rögner M, Willner I, Kaplan A, Schuster G, Nelson N, Lubitz W, Nechushtai R. Cryo-EM photosystem I structure reveals adaptation mechanisms to extreme high light in Chlorella ohadii. NATURE PLANTS 2021; 7:1314-1322. [PMID: 34462576 DOI: 10.1038/s41477-021-00983-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 07/07/2021] [Indexed: 05/10/2023]
Abstract
Photosynthesis in deserts is challenging since it requires fast adaptation to rapid night-to-day changes, that is, from dawn's low light (LL) to extreme high light (HL) intensities during the daytime. To understand these adaptation mechanisms, we purified photosystem I (PSI) from Chlorella ohadii, a green alga that was isolated from a desert soil crust, and identified the essential functional and structural changes that enable the photosystem to perform photosynthesis under extreme high light conditions. The cryo-electron microscopy structures of PSI from cells grown under low light (PSILL) and high light (PSIHL), obtained at 2.70 and 2.71 Å, respectively, show that part of light-harvesting antenna complex I (LHCI) and the core complex subunit (PsaO) are eliminated from PSIHL to minimize the photodamage. An additional change is in the pigment composition and their number in LHCIHL; about 50% of chlorophyll b is replaced by chlorophyll a. This leads to higher electron transfer rates in PSIHL and might enable C. ohadii PSI to act as a natural photosynthesiser in photobiocatalytic systems. PSIHL or PSILL were attached to an electrode and their induced photocurrent was determined. To obtain photocurrents comparable with PSIHL, 25 times the amount of PSILL was required, demonstrating the high efficiency of PSIHL. Hence, we suggest that C. ohadii PSIHL is an ideal candidate for the design of desert artificial photobiocatalytic systems.
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Affiliation(s)
- Ido Caspy
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ehud Neumann
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maria Fadeeva
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Varda Liveanu
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Anton Savitsky
- Faculty of Physics, Technical University Dortmund, Dortmund, Germany
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany
| | - Anna Frank
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Yael Levi Kalisman
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
- The Centre for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yoel Shkolnisky
- School of Mathematical Sciences, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Omer Murik
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Haim Treves
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Volker Hartmann
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Marc M Nowaczyk
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Wolfgang Schuhmann
- Analytical Chemistry-Centre for Electrochemical Sciences (CES), Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Matthias Rögner
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Itamar Willner
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Aaron Kaplan
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Gadi Schuster
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Nathan Nelson
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany.
| | - Rachel Nechushtai
- Institute of Life Science, Faculty of Science and Mathematics, The Hebrew University of Jerusalem, Jerusalem, Israel.
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Schreiber U, Klughammer C. Evidence for variable chlorophyll fluorescence of photosystem I in vivo. PHOTOSYNTHESIS RESEARCH 2021; 149:213-231. [PMID: 33464442 PMCID: PMC8382641 DOI: 10.1007/s11120-020-00814-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/16/2020] [Indexed: 05/09/2023]
Abstract
Room temperature fluorescence in vivo and its light-induced changes are dominated by chlorophyll a fluorescence excited in photosystem II, F(II), peaking around 685 nm. Photosystem I fluorescence, F(I), peaking around 730 nm, so far has been assumed to be constant in vivo. Here, we present evidence for significant contributions of F(I) to variable fluorescence in the green unicellular alga Chlorella vulgaris, the cyanobacterium Synechococcus leopoliensis and a light-green ivy leaf. A Multi-Color-PAM fluorometer was applied for measurements of the polyphasic fluorescence rise (O-I1-I2-P) induced by strong 440 nm light in a dilute suspension of Chlorella, with detection alternating between emission above 700 nm (F > 700) and below 710 nm (F < 710). By averaging 10 curves each of the F > 700 and F < 710 recordings even small differences could be reliably evaluated. After equalizing the amplitudes of the O-I1 phase, which constitutes a specific F(II) response, the O-I1-I2 parts of the two recordings were close to identical, whereas the I2-P phase was larger in F > 700 than in F < 710 by a factor of 1.42. In analogous measurements with Synechococcus carried out in the dark state 2 using strong 625 nm actinic light, after O-I1 equalization the I2-P phase in F > 700 exceeded that in F < 710 even by a factor of 1.99. In measurements with Chlorella, the I2-P phase and with it the apparent variable fluorescence of PS I, Fv(I), were suppressed by moderate actinic background light and by the plastoquinone antagonist DBMIB. Analogous measurements with leaves are rendered problematic by unavoidable light intensity gradients and the resulting heterogenic origins of F > 700 and F < 710. However, a light-green young ivy leaf gave qualitatively similar results as those obtained with the suspensions, thus strongly suggesting the existence of Fv(I) also in leaves.
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Affiliation(s)
- Ulrich Schreiber
- Julius-Von-Sachs Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs Platz 2, 97082, Würzburg, Germany.
| | - Christof Klughammer
- Julius-Von-Sachs Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs Platz 2, 97082, Würzburg, Germany
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Pfündel EE. Simultaneously measuring pulse-amplitude-modulated (PAM) chlorophyll fluorescence of leaves at wavelengths shorter and longer than 700 nm. PHOTOSYNTHESIS RESEARCH 2021; 147:345-358. [PMID: 33528756 DOI: 10.1007/s11120-021-00821-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
PAM fluorescence of leaves of cherry laurel (Prunus laurocerasus L.) was measured simultaneously in the spectral range below 700 nm (sw) and above 700 nm (lw). A high-sensitivity photodiode was employed to measure the low intensities of sw fluorescence. Photosystem II (PSII) performance was analyzed by the saturation pulse method during a light response curve with subsequent dark phase. The sw fluorescence was more variable, resulting in higher PSII photochemical yields compared to lw fluorescence. The variations between sw and lw data were explained by different levels of photosystem I (PSI) fluorescence: the contribution of PSI fluorescence to minimum fluorescence (F0) was calculated to be 14% at sw wavelengths and 45% at lw wavelengths. With the results obtained, the validity of an earlier method for the quantification of PSI fluorescence (Genty et al. in Photosynth Res 26:133-139, 1990, https://doi.org/10.1007/BF00047085 ) was reconsidered. After subtracting PSI fluorescence from all fluorescence levels, the maximum PSII photochemical yield (FV/FM) in the sw range was 0.862 and it was 0.883 in the lw range. The lower FV/FM at sw wavelengths was suggested to arise from inactive PSII reaction centers in the outermost leaf layers. Polyphasic fluorescence transients (OJIP or OI1I2P kinetics) were recorded simultaneously at sw and lw wavelengths: the slowest phase of the kinetics (IP or I2P) corresponded to 11% and 13% of total variable sw and lw fluorescence, respectively. The idea that this difference is due to variable PSI fluorescence is critically discussed. Potential future applications of simultaneously recording fluorescence in two spectral windows include studies of PSI non-photochemical quenching and state I-state II transitions, as well as measuring the fluorescence from pH-sensitive dyes simultaneously with chlorophyll fluorescence.
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11
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Polylysine effect on thylakoid membranes. Biophys Chem 2020; 266:106440. [DOI: 10.1016/j.bpc.2020.106440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 01/06/2023]
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12
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Stirbet A, Lazár D, Guo Y, Govindjee G. Photosynthesis: basics, history and modelling. ANNALS OF BOTANY 2020; 126:511-537. [PMID: 31641747 PMCID: PMC7489092 DOI: 10.1093/aob/mcz171] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/06/2019] [Accepted: 10/21/2019] [Indexed: 05/02/2023]
Abstract
BACKGROUND With limited agricultural land and increasing human population, it is essential to enhance overall photosynthesis and thus productivity. Oxygenic photosynthesis begins with light absorption, followed by excitation energy transfer to the reaction centres, primary photochemistry, electron and proton transport, NADPH and ATP synthesis, and then CO2 fixation (Calvin-Benson cycle, as well as Hatch-Slack cycle). Here we cover some of the discoveries related to this process, such as the existence of two light reactions and two photosystems connected by an electron transport 'chain' (the Z-scheme), chemiosmotic hypothesis for ATP synthesis, water oxidation clock for oxygen evolution, steps for carbon fixation, and finally the diverse mechanisms of regulatory processes, such as 'state transitions' and 'non-photochemical quenching' of the excited state of chlorophyll a. SCOPE In this review, we emphasize that mathematical modelling is a highly valuable tool in understanding and making predictions regarding photosynthesis. Different mathematical models have been used to examine current theories on diverse photosynthetic processes; these have been validated through simulation(s) of available experimental data, such as chlorophyll a fluorescence induction, measured with fluorometers using continuous (or modulated) exciting light, and absorbance changes at 820 nm (ΔA820) related to redox changes in P700, the reaction centre of photosystem I. CONCLUSIONS We highlight here the important role of modelling in deciphering and untangling complex photosynthesis processes taking place simultaneously, as well as in predicting possible ways to obtain higher biomass and productivity in plants, algae and cyanobacteria.
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Affiliation(s)
| | - Dušan Lazár
- Department of Biophysics, Center of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Ya Guo
- Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Jiangnan University, Wuxi, China
- University of Missouri, Columbia, MO, USA
| | - Govindjee Govindjee
- Department of Biochemistry, Department of Plant Biology, and Center of Biophysics & Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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13
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Chukhutsina VU, Liu X, Xu P, Croce R. Light-harvesting complex II is an antenna of photosystem I in dark-adapted plants. NATURE PLANTS 2020; 6:860-868. [PMID: 32572215 DOI: 10.1038/s41477-020-0693-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 05/14/2020] [Indexed: 05/19/2023]
Abstract
Photosystem I (PSI) is a major player in the light reactions of photosynthesis. In higher plants, it consists of a core complex and four external antennae, Lhca1-4 forming the PSI-light-harvesting complex I (LHCI) supercomplex. The protein and pigment composition as well as the spectroscopic properties of this complex are considered to be identical in different higher plant species. In addition to the four Lhca, a pool of mobile LHCII increases the antenna size of PSI under most light conditions. In this work, we have first investigated purified PSI complexes and then PSI in vivo upon long-term dark-adaptation of four well-studied plant species: Arabidopsis thaliana, Zea mays, Nicotiana tabacum and Hordeum vulgare. By performing time-resolved fluorescence measurements, we show that LHCII is associated with PSI also in a dark-adapted state in all the plant species investigated. The number of LHCII subunits per PSI is plant-dependent, varying between one and three. Furthermore, we show that the spectroscopic properties of PSI-LHCI supercomplexes differ in different plants.
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Affiliation(s)
- Volha U Chukhutsina
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, Amsterdam, the Netherlands
| | - Xin Liu
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, Amsterdam, the Netherlands
| | - Pengqi Xu
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, Amsterdam, the Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, Amsterdam, the Netherlands.
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14
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Bos P, Oosterwijk A, Koehorst R, Bader A, Philippi J, van Amerongen H, Wientjes E. Digitonin-sensitive LHCII enlarges the antenna of Photosystem I in stroma lamellae of Arabidopsis thaliana after far-red and blue-light treatment. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:651-658. [PMID: 31299182 DOI: 10.1016/j.bbabio.2019.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 06/14/2019] [Accepted: 07/07/2019] [Indexed: 11/16/2022]
Abstract
Light drives photosynthesis. In plants it is absorbed by light-harvesting antenna complexes associated with Photosystem I (PSI) and photosystem II (PSII). As PSI and PSII work in series, it is important that the excitation pressure on the two photosystems is balanced. When plants are exposed to illumination that overexcites PSII, a special pool of the major light-harvesting complex LHCII is phosphorylated and moves from PSII to PSI (state 2). If instead PSI is over-excited the LHCII complex is dephosphorylated and moves back to PSII (state 1). Recent findings have suggested that LHCII might also transfer energy to PSI in state 1. In this work we used a combination of biochemistry and (time-resolved) fluorescence spectroscopy to investigate the PSI antenna size in state 1 and state 2 for Arabidopsis thaliana. Our data shows that 0.7 ± 0.1 unphosphorylated LHCII trimers per PSI are present in the stroma lamellae of state-1 plants. Upon transition to state 2 the antenna size of PSI in the stroma membrane increases with phosphorylated LHCIIs to a total of 1.2 ± 0.1 LHCII trimers per PSI. Both phosphorylated and unphosphorylated LHCII function as highly efficient PSI antenna.
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Affiliation(s)
- Peter Bos
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Anniek Oosterwijk
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Rob Koehorst
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Arjen Bader
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - John Philippi
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands.
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15
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Farooq S, Chmeliov J, Wientjes E, Koehorst R, Bader A, Valkunas L, Trinkunas G, van Amerongen H. Dynamic feedback of the photosystem II reaction centre on photoprotection in plants. NATURE PLANTS 2018; 4:225-231. [PMID: 29610535 DOI: 10.1038/s41477-018-0127-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 03/01/2018] [Indexed: 05/08/2023]
Abstract
Photosystem II of higher plants is protected against light damage by thermal dissipation of excess excitation energy, a process that can be monitored through non-photochemical quenching of chlorophyll fluorescence. When the light intensity is lowered, non-photochemical quenching largely disappears on a time scale ranging from tens of seconds to many minutes. With the use of picosecond fluorescence spectroscopy, we demonstrate that one of the underlying mechanisms is only functional when the reaction centre of photosystem II is closed, that is when electron transfer is blocked and the risk of photodamage is high. This is accompanied by the appearance of a long-wavelength fluorescence band. As soon as the reaction centre reopens, this quenching, together with the long-wavelength fluorescence, disappears instantaneously. This allows plants to maintain a high level of photosynthetic efficiency even in dangerous high-light conditions.
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Affiliation(s)
- Shazia Farooq
- Laboratory of Biophysics, Wageningen University and Research, Wageningen, the Netherlands
| | - Jevgenij Chmeliov
- Institute of Chemical Physics, Faculty of Physics, Vilnius University, Vilnius, Lithuania
- Department of Molecular Compound Physics, Centre for Physical Sciences and Technology, Vilnius, Lithuania
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University and Research, Wageningen, the Netherlands
| | - Rob Koehorst
- Laboratory of Biophysics, Wageningen University and Research, Wageningen, the Netherlands
| | - Arjen Bader
- Laboratory of Biophysics, Wageningen University and Research, Wageningen, the Netherlands
- MicroSpectroscopy Research Facility, Wageningen University and Research, Wageningen, the Netherlands
| | - Leonas Valkunas
- Institute of Chemical Physics, Faculty of Physics, Vilnius University, Vilnius, Lithuania
- Department of Molecular Compound Physics, Centre for Physical Sciences and Technology, Vilnius, Lithuania
| | - Gediminas Trinkunas
- Department of Molecular Compound Physics, Centre for Physical Sciences and Technology, Vilnius, Lithuania
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University and Research, Wageningen, the Netherlands.
- MicroSpectroscopy Research Facility, Wageningen University and Research, Wageningen, the Netherlands.
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16
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Akhtar P, Zhang C, Liu Z, Tan HS, Lambrev PH. Excitation transfer and trapping kinetics in plant photosystem I probed by two-dimensional electronic spectroscopy. PHOTOSYNTHESIS RESEARCH 2018; 135:239-250. [PMID: 28808836 DOI: 10.1007/s11120-017-0427-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/01/2017] [Indexed: 05/24/2023]
Abstract
Photosystem I is a robust and highly efficient biological solar engine. Its capacity to utilize virtually every absorbed photon's energy in a photochemical reaction generates great interest in the kinetics and mechanisms of excitation energy transfer and charge separation. In this work, we have employed room-temperature coherent two-dimensional electronic spectroscopy and time-resolved fluorescence spectroscopy to follow exciton equilibration and excitation trapping in intact Photosystem I complexes as well as core complexes isolated from Pisum sativum. We performed two-dimensional electronic spectroscopy measurements with low excitation pulse energies to record excited-state kinetics free from singlet-singlet annihilation. Global lifetime analysis resolved energy transfer and trapping lifetimes closely matches the time-correlated single-photon counting data. Exciton energy equilibration in the core antenna occurred on a timescale of 0.5 ps. We further observed spectral equilibration component in the core complex with a 3-4 ps lifetime between the bulk Chl states and a state absorbing at 700 nm. Trapping in the core complex occurred with a 20 ps lifetime, which in the supercomplex split into two lifetimes, 16 ps and 67-75 ps. The experimental data could be modelled with two alternative models resulting in equally good fits-a transfer-to-trap-limited model and a trap-limited model. However, the former model is only possible if the 3-4 ps component is ascribed to equilibration with a "red" core antenna pool absorbing at 700 nm. Conversely, if these low-energy states are identified with the P700 reaction centre, the transfer-to-trap-model is ruled out in favour of a trap-limited model.
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Affiliation(s)
- Parveen Akhtar
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged, 6726, Hungary
| | - Cheng Zhang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Zhengtang Liu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
| | - Petar H Lambrev
- Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged, 6726, Hungary.
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17
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Wientjes E, Philippi J, Borst JW, van Amerongen H. Imaging the Photosystem I/Photosystem II chlorophyll ratio inside the leaf. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:259-265. [DOI: 10.1016/j.bbabio.2017.01.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/10/2017] [Accepted: 01/13/2017] [Indexed: 02/03/2023]
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18
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Introducing extra NADPH consumption ability significantly increases the photosynthetic efficiency and biomass production of cyanobacteria. Metab Eng 2016; 38:217-227. [PMID: 27497972 DOI: 10.1016/j.ymben.2016.08.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/28/2016] [Accepted: 08/04/2016] [Indexed: 11/20/2022]
Abstract
Increasing photosynthetic efficiency is crucial to increasing biomass production to meet the growing demands for food and energy. Previous theoretical arithmetic analysis suggests that the light reactions and dark reactions are imperfectly coupled due to shortage of ATP supply, or accumulation of NADPH. Here we hypothesized that solely increasing NADPH consumption might improve the coupling of light reactions and dark reactions, thereby increasing the photosynthetic efficiency and biomass production. To test this hypothesis, an NADPH consumption pathway was constructed in cyanobacterium Synechocystis sp. PCC 6803. The resulting extra NADPH-consuming mutant grew much faster and achieved a higher biomass concentration. Analyses of photosynthesis characteristics showed the activities of photosystem II and photosystem I and the light saturation point of the NADPH-consuming mutant all significantly increased. Thus, we demonstrated that introducing extra NADPH consumption ability is a promising strategy to increase photosynthetic efficiency and to enable utilization of high-intensity lights.
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19
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Bína D, Herbstová M, Gardian Z, Vácha F, Litvín R. Novel structural aspect of the diatom thylakoid membrane: lateral segregation of photosystem I under red-enhanced illumination. Sci Rep 2016; 6:25583. [PMID: 27149693 PMCID: PMC4857733 DOI: 10.1038/srep25583] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/20/2016] [Indexed: 01/01/2023] Open
Abstract
Spatial segregation of photosystems in the thylakoid membrane (lateral heterogeneity) observed in plants and in the green algae is usually considered to be absent in photoautotrophs possessing secondary plastids, such as diatoms. Contrary to this assumption, here we show that thylakoid membranes in the chloroplast of a marine diatom, Phaeodactylum tricornutum, contain large areas occupied exclusively by a supercomplex of photosystem I (PSI) and its associated Lhcr antenna. These membrane areas, hundreds of nanometers in size, comprise hundreds of tightly packed PSI-antenna complexes while lacking other components of the photosynthetic electron transport chain. Analyses of the spatial distribution of the PSI-Lhcr complexes have indicated elliptical particles, each 14 × 17 nm in diameter. On larger scales, the red-enhanced illumination exerts a significant effect on the ultrastructure of chloroplasts, creating superstacks of tens of thylakoid membranes.
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Affiliation(s)
- David Bína
- Institute of Plant Molecular Biology, Biology Centre CAS, Department of Photosynthesis, Branišovská 31, České Budějovice, 37005, Czech Republic.,Faculty of Science, University of South Bohemia, Institute of Chemistry and Biochemistry, Branišovská 1760, České Budějovice, 37005, Czech Republic
| | - Miroslava Herbstová
- Institute of Plant Molecular Biology, Biology Centre CAS, Department of Photosynthesis, Branišovská 31, České Budějovice, 37005, Czech Republic.,Faculty of Science, University of South Bohemia, Institute of Chemistry and Biochemistry, Branišovská 1760, České Budějovice, 37005, Czech Republic
| | - Zdenko Gardian
- Institute of Plant Molecular Biology, Biology Centre CAS, Department of Photosynthesis, Branišovská 31, České Budějovice, 37005, Czech Republic.,Faculty of Science, University of South Bohemia, Institute of Chemistry and Biochemistry, Branišovská 1760, České Budějovice, 37005, Czech Republic
| | - František Vácha
- Institute of Plant Molecular Biology, Biology Centre CAS, Department of Photosynthesis, Branišovská 31, České Budějovice, 37005, Czech Republic.,Faculty of Science, University of South Bohemia, Institute of Chemistry and Biochemistry, Branišovská 1760, České Budějovice, 37005, Czech Republic
| | - Radek Litvín
- Institute of Plant Molecular Biology, Biology Centre CAS, Department of Photosynthesis, Branišovská 31, České Budějovice, 37005, Czech Republic.,Faculty of Science, University of South Bohemia, Institute of Chemistry and Biochemistry, Branišovská 1760, České Budějovice, 37005, Czech Republic
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20
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Tongra T, Jajoo A. Investigating changes in the redox state of Photosystem I at low pH. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 151:25-30. [PMID: 26151897 DOI: 10.1016/j.jphotobiol.2015.06.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 06/30/2015] [Accepted: 06/30/2015] [Indexed: 11/29/2022]
Abstract
Changes in the redox state of Photosystem I (PSI) were studied in spinach leaf discs suspended in buffers of different pH (pH 7.5, 6.5, 5.5 and 4.5). By measuring absorbance changes at 820 nm, it was observed that under normal conditions, the electrons were supplied by Photosystem II (PSII) for the photo-oxidation of P700 while in the presence of DCMU when electrons coming from PSII are blocked, cyclic electron flow (CEF) around PSI was the major source for the absorbance changes observed at 820 nm. This was supported by complete inhibition in the reduction of both single turnover (ST) area and multiple turnover (MT) area, in the presence of DCMU, which is generally filled up by the electrons coming from PSII. In the absence of DCMU, the intersystem electron pool or plastoquinone (PQ) pool was increased at low pH which was probably due to enhanced cyclic electron flow around PSI. Our results also suggest that at low pH, in the absence of DCMU, the major contribution for faster dark re-reduction of P700(+) is attributed mainly by PSII and CEF PSI while in the presence of DCMU, the significant contribution is provided by CEF PSI and other stromal components.
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Affiliation(s)
- Teena Tongra
- School of Life Science, Devi Ahilya University, Indore 452017, M.P., India
| | - Anjana Jajoo
- School of Life Science, Devi Ahilya University, Indore 452017, M.P., India.
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21
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Le Quiniou C, Tian L, Drop B, Wientjes E, van Stokkum IHM, van Oort B, Croce R. PSI-LHCI of Chlamydomonas reinhardtii: Increasing the absorption cross section without losing efficiency. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1847:458-467. [PMID: 25681242 PMCID: PMC4547092 DOI: 10.1016/j.bbabio.2015.02.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/28/2015] [Accepted: 02/02/2015] [Indexed: 11/28/2022]
Abstract
Photosystem I (PSI) is an essential component of photosynthetic membranes. Despite the high sequence and structural homologies, its absorption properties differ substantially in algae, plants and cyanobacteria. In particular it is characterized by the presence of low-energy chlorophylls (red forms), the number and the energy of which vary in different organisms. The PSI-LHCI (PSI-light harvesting complex I) complex of the green alga Chlamydomonas reinhardtii (C.r.) is significantly larger than that of plants, containing five additional light-harvesting complexes (together binding≈65 chlorophylls), and contains red forms with higher energy than plants. To understand how these differences influence excitation energy transfer and trapping in the system, we studied two PSI-LHCI C.r. particles, differing in antenna size and red-form content, using time-resolved fluorescence and compared them to plant PSI-LHCI. The excited state kinetics in C.r. shows the same average lifetime (50 ps) as in plants suggesting that the effect of antenna enlargement is compensated by higher energy red forms. The system equilibrates very fast, indicating that all Lhcas are well-connected, despite their long distance to the core. The differences between C.r. PSI-LHCI with and without Lhca2 and Lhca9 show that these Lhcas bind red forms, although not the red-most. The red-most forms are in (or functionally close to) other Lhcas and slow down the trapping, but hardly affect the quantum efficiency, which remains as high as 97% even in a complex that contains 235 chlorophylls.
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Affiliation(s)
- Clotilde Le Quiniou
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Institute for Lasers, Life and Biophotonics Amsterdam, LaserLaB Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Lijin Tian
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Institute for Lasers, Life and Biophotonics Amsterdam, LaserLaB Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Bartlomiej Drop
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Institute for Lasers, Life and Biophotonics Amsterdam, LaserLaB Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Emilie Wientjes
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Institute for Lasers, Life and Biophotonics Amsterdam, LaserLaB Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Ivo H M van Stokkum
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Institute for Lasers, Life and Biophotonics Amsterdam, LaserLaB Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Bart van Oort
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Institute for Lasers, Life and Biophotonics Amsterdam, LaserLaB Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Roberta Croce
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Institute for Lasers, Life and Biophotonics Amsterdam, LaserLaB Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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22
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Stamatakis K, Papageorgiou GC. ΔpH-dependent non-photochemical quenching (qE) of excited chlorophylls in the photosystem II core complex of the freshwater cyanobacterium Synechococcus sp PCC 7942. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 81:184-189. [PMID: 24793104 DOI: 10.1016/j.plaphy.2014.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 04/08/2014] [Indexed: 06/03/2023]
Abstract
Light-induced and lumen acidity-dependent quenching (qE) of excited chlorophylls (Chl) in vivo has been amply documented in plants and algae, but not in cyanobacteria, using primarily the saturation pulse method of quenching analysis which is applied to continuously illuminated samples. This method is unsuitable for cyanobacteria because the background illumination elicits in them a very large Chl a fluorescence signal, due to a state 2 to state 1 transition, which masks fluorescence changes due to other causes. We investigated the qE problem in the cyanobacterium Synechococcus sp. PCC 7942 using a kinetic method (Chl a fluorescence induction) with which qE can be examined before the onset of the state 2 to state 1 transition and the attendant rise of Chl a fluorescence. Our results confirm the existence of a qE mechanism that operates on excited Chls a in Photosystem II core complexes of cyanobacteria.
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Affiliation(s)
- Kostas Stamatakis
- Institute of Biosciences and Applications, National Center for Scientific Research Demokritos, Aghia Paraskevi Attikis 15310, Greece.
| | - George C Papageorgiou
- Institute of Biosciences and Applications, National Center for Scientific Research Demokritos, Aghia Paraskevi Attikis 15310, Greece
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23
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Schansker G, Tóth SZ, Holzwarth AR, Garab G. Chlorophyll a fluorescence: beyond the limits of the Q(A) model. PHOTOSYNTHESIS RESEARCH 2014; 120:43-58. [PMID: 23456268 DOI: 10.1007/s11120-013-9806-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 02/18/2013] [Indexed: 05/03/2023]
Abstract
Chlorophyll a fluorescence is a non-invasive tool widely used in photosynthesis research. According to the dominant interpretation, based on the model proposed by Duysens and Sweers (1963, Special Issue of Plant and Cell Physiology, pp 353-372), the fluorescence changes reflect primarily changes in the redox state of Q(A), the primary quinone electron acceptor of photosystem II (PSII). While it is clearly successful in monitoring the photochemical activity of PSII, a number of important observations cannot be explained within the framework of this simple model. Alternative interpretations have been proposed but were not supported satisfactorily by experimental data. In this review we concentrate on the processes determining the fluorescence rise on a dark-to-light transition and critically analyze the experimental data and the existing models. Recent experiments have provided additional evidence for the involvement of a second process influencing the fluorescence rise once Q(A) is reduced. These observations are best explained by a light-induced conformational change, the focal point of our review. We also want to emphasize that-based on the presently available experimental findings-conclusions on α/ß-centers, PSII connectivity, and the assignment of FV/FM to the maximum PSII quantum yield may require critical re-evaluations. At the same time, it has to be emphasized that for a deeper understanding of the underlying physical mechanism(s) systematic studies on light-induced changes in the structure and reaction kinetics of the PSII reaction center are required.
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Affiliation(s)
- Gert Schansker
- Institute of Plant Biology, Biological Research Center Szeged, Hungarian Academy of Sciences, Szeged, 6701, Hungary,
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24
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Simulations show that a small part of variable chlorophyll a fluorescence originates in photosystem I and contributes to overall fluorescence rise. J Theor Biol 2013; 335:249-64. [DOI: 10.1016/j.jtbi.2013.06.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Revised: 06/19/2013] [Accepted: 06/21/2013] [Indexed: 12/15/2022]
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25
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Stirbet A. Excitonic connectivity between photosystem II units: what is it, and how to measure it? PHOTOSYNTHESIS RESEARCH 2013; 116:189-214. [PMID: 23794168 DOI: 10.1007/s11120-013-9863-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/26/2013] [Indexed: 05/22/2023]
Abstract
In photosynthetic organisms, light energy is absorbed by a complex network of chromophores embedded in light-harvesting antenna complexes. In photosystem II (PSII), the excitation energy from the antenna is transferred very efficiently to an active reaction center (RC) (i.e., with oxidized primary quinone acceptor Q(A)), where the photochemistry begins, leading to O2 evolution, and reduction of plastoquinones. A very small part of the excitation energy is dissipated as fluorescence and heat. Measurements on chlorophyll (Chl) fluorescence and oxygen have shown that a nonlinear (hyperbolic) relationship exists between the fluorescence yield (Φ(F)) (or the oxygen emission yield, (Φ(O2)) and the fraction of closed PSII RCs (i.e., with reduced Q(A)). This nonlinearity is assumed to be related to the transfer of the excitation energy from a closed PSII RC to an open (active) PSII RC, a process called PSII excitonic connectivity by Joliot and Joliot (CR Acad Sci Paris 258: 4622-4625, 1964). Different theoretical approaches of the PSII excitonic connectivity, and experimental methods used to measure it, are discussed in this review. In addition, we present alternative explanations of the observed sigmoidicity of the fluorescence induction and oxygen evolution curves.
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26
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Stirbet A. Excitonic connectivity between photosystem II units: what is it, and how to measure it? PHOTOSYNTHESIS RESEARCH 2013; 116:189-214. [PMID: 23794168 DOI: 10.1007/s11120-013-9863-9:inpress] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/26/2013] [Indexed: 05/28/2023]
Abstract
In photosynthetic organisms, light energy is absorbed by a complex network of chromophores embedded in light-harvesting antenna complexes. In photosystem II (PSII), the excitation energy from the antenna is transferred very efficiently to an active reaction center (RC) (i.e., with oxidized primary quinone acceptor Q(A)), where the photochemistry begins, leading to O2 evolution, and reduction of plastoquinones. A very small part of the excitation energy is dissipated as fluorescence and heat. Measurements on chlorophyll (Chl) fluorescence and oxygen have shown that a nonlinear (hyperbolic) relationship exists between the fluorescence yield (Φ(F)) (or the oxygen emission yield, (Φ(O2)) and the fraction of closed PSII RCs (i.e., with reduced Q(A)). This nonlinearity is assumed to be related to the transfer of the excitation energy from a closed PSII RC to an open (active) PSII RC, a process called PSII excitonic connectivity by Joliot and Joliot (CR Acad Sci Paris 258: 4622-4625, 1964). Different theoretical approaches of the PSII excitonic connectivity, and experimental methods used to measure it, are discussed in this review. In addition, we present alternative explanations of the observed sigmoidicity of the fluorescence induction and oxygen evolution curves.
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Chukhutsina V, Büchel C, van Amerongen H. Variations in the first steps of photosynthesis for the diatom Cyclotella meneghiniana grown under different light conditions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:10-8. [DOI: 10.1016/j.bbabio.2012.09.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/19/2012] [Accepted: 09/25/2012] [Indexed: 12/14/2022]
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Tian L, Farooq S, van Amerongen H. Probing the picosecond kinetics of the photosystem II core complex in vivo. Phys Chem Chem Phys 2013; 15:3146-54. [DOI: 10.1039/c3cp43813a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tian L, van Stokkum IHM, Koehorst RBM, van Amerongen H. Light Harvesting and Blue-Green Light Induced Non-Photochemical Quenching in Two Different C-Phycocyanin Mutants of Synechocystis PCC 6803. J Phys Chem B 2012; 117:11000-6. [DOI: 10.1021/jp309570u] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Lijin Tian
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen,
The Netherlands
| | - Ivo H. M. van Stokkum
- Biophysics
Group, Department
of Physics and Astronomy, Faculty of Sciences, VU University, DeBoelelaan1081, 1081 HV Amsterdam, The Netherlands
| | - Rob B. M. Koehorst
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen,
The Netherlands
- MicroSpectroscopy Centre, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen,
The Netherlands
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen,
The Netherlands
- MicroSpectroscopy Centre, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen,
The Netherlands
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McConnell MD, Cowgill JB, Baker PL, Rappaport F, Redding KE. Double reduction of plastoquinone to plastoquinol in photosystem 1. Biochemistry 2011; 50:11034-46. [PMID: 22103567 DOI: 10.1021/bi201131r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In Photosystem 1 (PS1), phylloquinone (PhQ) acts as a secondary electron acceptor from chlorophyll ec(3) and also as an electron donor to the iron-sulfur cluster F(X). PS1 possesses two virtually equivalent branches of electron transfer (ET) cofactors from P(700) to F(X), and the lifetime of the semiquinone intermediate displays biphasic kinetics, reflecting ET along the two different branches. PhQ in PS1 serves only as an intermediate in ET and is not normally fully reduced to the quinol form. This is in contrast to PS2, in which plastoquinone (PQ) is doubly reduced to plastoquinol (PQH(2)) as the terminal electron acceptor. We purified PS1 particles from the menD1 mutant of Chlamydomonas reinhardtii that cannot synthesize PhQ, resulting in replacement of PhQ by PQ in the quinone-binding pocket. The magnitude of the stable flash-induced P(700)(+) signal of menD1 PS1, but not wild-type PS1, decreased during a train of laser flashes, as it was replaced by a ~30 ns back-reaction from the preceding radical pair (P(700)(+)A(0)(-)). We show that this process of photoinactivation is due to double reduction of PQ in the menD1 PS1 and have characterized the process. It is accelerated at lower pH, consistent with a rate-limiting protonation step. Moreover, a point mutation (PsaA-L722T) in the PhQ(A) site that accelerates ET to F(X) ~2-fold, likely by weakening the sole H-bond to PhQ(A), also accelerates the photoinactivation process. The addition of exogenous PhQ can restore activity to photoinactivated PS1 and confer resistance to further photoinactivation. This process also occurs with PS1 purified from the menB PhQ biosynthesis mutant of Synechocystis PCC 6803, demonstrating that it is a general phenomenon in both prokaryotic and eukaryotic PS1.
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Affiliation(s)
- Michael D McConnell
- Department of Chemistry and Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604, United States.
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