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Govindjee G, Amesz B, Garab G, Stirbet A. Remembering Jan Amesz (1934-2001): a great gentleman, a major discoverer, and an internationally renowned biophysicist of both oxygenic and anoxygenic photosynthesis a. Photosynth Res 2024:10.1007/s11120-024-01102-9. [PMID: 38687462 DOI: 10.1007/s11120-024-01102-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/18/2024] [Indexed: 05/02/2024]
Abstract
We present here the research contributions of Jan Amesz (1934-2001) on deciphering the details of the early physico-chemical steps in oxygenic photosynthesis in plants, algae and cyanobacteria, as well as in anoxygenic photosynthesis in purple, green, and heliobacteria. His research included light absorption and the mechanism of excitation energy transfer, primary photochemistry, and electron transfer steps until the reduction of pyridine nucleotides. Among his many discoveries, we emphasize his 1961 proof, with L. N. M. Duysens, of the "series scheme" of oxygenic photosynthesis, through antagonistic effects of Light I and II on the redox state of cytochrome f. Further, we highlight the following research on oxygenic photosynthesis: the experimental direct proof that plastoquinone and plastocyanin function at their respective places in the Z-scheme. In addition, Amesz's major contributions were in unraveling the mechanism of excitation energy transfer and electron transport steps in anoxygenic photosynthetic bacteria (purple, green and heliobacteria). Before we present his research, focusing on his key discoveries, we provide a glimpse of his personal life. We end this Tribute with reminiscences from three of his former doctoral students (Sigi Neerken; Hjalmar Pernentier, and Frank Kleinherenbrink) and from several scientists (Suleyman Allakhverdiev; Robert Blankenship; Richard Cogdell) including two of the authors (G. Garab and A. Stirbet) of this Tribute.
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Affiliation(s)
- Govindjee Govindjee
- Department of Plant Biology, Department of Biochemistry, and the Center of Biophysics & Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
| | - Bas Amesz
- Albertus Perkstraat 35, 1217 NL, Hilversum, The Netherlands
| | - Győző Garab
- Biological Research Centre, Institute of Plant Biology, HUN-REN, 6726, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, 71000, Ostrava, Czech Republic
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Böde K, Javornik U, Dlouhý O, Zsíros O, Biswas A, Domonkos I, Šket P, Karlický V, Ughy B, Lambrev PH, Špunda V, Plavec J, Garab G. Role of isotropic lipid phase in the fusion of photosystem II membranes. Photosynth Res 2024:10.1007/s11120-024-01097-3. [PMID: 38662326 DOI: 10.1007/s11120-024-01097-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 03/18/2024] [Indexed: 04/26/2024]
Abstract
It has been thoroughly documented, by using 31P-NMR spectroscopy, that plant thylakoid membranes (TMs), in addition to the bilayer (or lamellar, L) phase, contain at least two isotropic (I) lipid phases and an inverted hexagonal (HII) phase. However, our knowledge concerning the structural and functional roles of the non-bilayer phases is still rudimentary. The objective of the present study is to elucidate the origin of I phases which have been hypothesized to arise, in part, from the fusion of TMs (Garab et al. 2022 Progr Lipid Res 101,163). We take advantage of the selectivity of wheat germ lipase (WGL) in eliminating the I phases of TMs (Dlouhý et al. 2022 Cells 11: 2681), and the tendency of the so-called BBY particles, stacked photosystem II (PSII) enriched membrane pairs of 300-500 nm in diameter, to form large laterally fused sheets (Dunahay et al. 1984 BBA 764: 179). Our 31P-NMR spectroscopy data show that BBY membranes contain L and I phases. Similar to TMs, WGL selectively eliminated the I phases, which at the same time exerted no effect on the molecular organization and functional activity of PSII membranes. As revealed by sucrose-density centrifugation, magnetic linear dichroism spectroscopy and scanning electron microscopy, WGL disassembled the large laterally fused sheets. These data provide direct experimental evidence on the involvement of I phase(s) in the fusion of stacked PSII membrane pairs, and strongly suggest the role of non-bilayer lipids in the self-assembly of the TM system.
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Affiliation(s)
- Kinga Böde
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Uroš Javornik
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia
| | - Ondřej Dlouhý
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Ottó Zsíros
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Avratanu Biswas
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Ildikó Domonkos
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Primož Šket
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia
| | - Václav Karlický
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | - Bettina Ughy
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Petar H Lambrev
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Vladimír Špunda
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
- Global Change Research Institute of the Czech Academy of Sciences, Brno, Czech Republic
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
- EN-FIST Center of Excellence, Ljubljana, Slovenia
| | - Győző Garab
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary.
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic.
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Magyar M, Akhtar P, Sipka G, Domonkos I, Han W, Li X, Han G, Shen JR, Lambrev PH, Garab G. Effects of lipids on the rate-limiting steps in the dark-to-light transition of Photosystem II core complex of Thermostichus vulcanus. Front Plant Sci 2024; 15:1381040. [PMID: 38576791 PMCID: PMC10991767 DOI: 10.3389/fpls.2024.1381040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/11/2024] [Indexed: 04/06/2024]
Abstract
In our earlier works, we have shown that the rate-limiting steps, associated with the dark-to-light transition of Photosystem II (PSII), reflecting the photochemical activity and structural dynamics of the reaction center complex, depend largely on the lipidic environment of the protein matrix. Using chlorophyll-a fluorescence transients (ChlF) elicited by single-turnover saturating flashes, it was shown that the half-waiting time (Δτ 1/2) between consecutive excitations, at which 50% of the fluorescence increment was reached, was considerably larger in isolated PSII complexes of Thermostichus (T.) vulcanus than in the native thylakoid membrane (TM). Further, it was shown that the addition of a TM lipid extract shortened Δτ 1/2 of isolated PSII, indicating that at least a fraction of the 'missing' lipid molecules, replaced by detergent molecules, caused the elongation of Δτ 1/2. Here, we performed systematic experiments to obtain information on the nature of TM lipids that are capable of decreasing Δτ 1/2. Our data show that while all lipid species shorten Δτ 1/2, the negatively charged lipid phosphatidylglycerol appears to be the most efficient species - suggesting its prominent role in determining the structural dynamics of PSII reaction center.
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Affiliation(s)
- Melinda Magyar
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Parveen Akhtar
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Gábor Sipka
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Ildikó Domonkos
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Wenhui Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xingyue Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Petar H. Lambrev
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Győző Garab
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czechia
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Ounoki R, Sóti A, Ünnep R, Sipka G, Sárvári É, Garab G, Solymosi K. Etioplasts are more susceptible to salinity stress than chloroplasts and photosynthetically active etio-chloroplasts of wheat (Triticum aestivum L.). Physiol Plant 2023; 175:e14100. [PMID: 38148250 DOI: 10.1111/ppl.14100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/05/2023] [Accepted: 11/06/2023] [Indexed: 12/28/2023]
Abstract
High soil salinity is a global problem in agriculture that directly affects seed germination and the development of the seedlings sown deep in the soil. To study how salinity affected plastid ultrastructure, leaf segments of 11-day-old light- and dark-grown (etiolated) wheat (Triticum aestivum L. cv. Mv Béres) seedlings were floated on Hoagland solution, 600 mM KCl:NaCl (1:1) salt or isosmotic polyethylene glycol solution for 4 h in the dark. Light-grown seedlings were also treated in the light. The same treatments were also performed on etio-chloroplasts of etiolated seedlings greened for different time periods. Salt stress induced slight to strong changes in the relative chlorophyll content, photosynthetic activity, and organization of thylakoid complexes. Measurements of malondialdehyde contents and high-temperature thermoluminescence indicated significantly increased oxidative stress and lipid peroxidation under salt treatment, except for light-grown leaves treated in the dark. In chloroplasts of leaf segments treated in the light, slight shrinkage of grana (determined by transmission electron microscopy and small-angle neutron scattering) was observed, while a swelling of the (pro)thylakoid lumen was observed in etioplasts. Salt-induced swelling disappeared after the onset of photosynthesis after 4 h of greening. Osmotic stress caused no significant alterations in plastid structure and only mild changes in their activities, indicating that the swelling of the (pro)thylakoid lumen and the physiological effects of salinity are rather associated with the ionic component of salt stress. Our data indicate that etioplasts of dark-germinated wheat seedlings are the most sensitive to salt stress, especially at the early stages of their greening.
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Affiliation(s)
- Roumaissa Ounoki
- Department of Plant Anatomy, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Adél Sóti
- Department of Plant Anatomy, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Renáta Ünnep
- Neutron Spectroscopy Department, HUN-REN Centre for Energy Research, Budapest, Hungary
| | - Gábor Sipka
- Institute of Plant Biology, HUN-REN Biological Research Center, Szeged, Hungary
| | - Éva Sárvári
- Department of Plant Physiology and Molecular Plant Biology, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Győző Garab
- Institute of Plant Biology, HUN-REN Biological Research Center, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Katalin Solymosi
- Department of Plant Anatomy, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Budapest, Hungary
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Garab G, Magyar M, Sipka G, Lambrev PH. New foundations for the physical mechanism of variable chlorophyll a fluorescence. Quantum efficiency versus the light-adapted state of photosystem II. J Exp Bot 2023; 74:5458-5471. [PMID: 37410874 DOI: 10.1093/jxb/erad252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/03/2023] [Indexed: 07/08/2023]
Abstract
Photosystem II (PSII) uses solar energy to oxidize water and delivers electrons to fix CO2. Although the structure at atomic resolution and the basic photophysical and photochemical functions of PSII are well understood, many important questions remain. The activity of PSII in vitro and in vivo is routinely monitored by recording the induction kinetics of chlorophyll a fluorescence (ChlF). According to the 'mainstream' model, the rise from the minimum level (Fo) to the maximum (Fm) of ChlF of dark-adapted PSII reflects the closure of all functionally active reaction centers, and the Fv/Fm ratio is equated with the maximum photochemical quantum yield of PSII (where Fv=Fm-Fo). However, this model has never been free of controversies. Recent experimental data from a number of studies have confirmed that the first single-turnover saturating flash (STSF), which generates the closed state (PSIIC), produces F1
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Affiliation(s)
- Győző Garab
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Melinda Magyar
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Gábor Sipka
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Petar H Lambrev
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
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Jajoo A, Subramanyam R, Garab G, Allakhverdiev SI. Honoring two stalwarts of photosynthesis research: Eva-Mari Aro and Govindjee. Photosynth Res 2023:10.1007/s11120-022-00988-7. [PMID: 36847891 DOI: 10.1007/s11120-022-00988-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/21/2022] [Indexed: 06/18/2023]
Abstract
On behalf of the entire photosynthesis community, it is an honor, for us, to write about two very eminent scientists who were recently recognised with a Lifetime Achievement Award from the International Society of Photosynthesis Research (ISPR) on August 5, 2022; this prestigious Award was given during the closing ceremony of the 18th International Congress on Photosynthesis Research in Dunedin, New Zealand. The awardees were: Professor Eva-Mari Aro (Finland) and Professor Emeritus Govindjee Govindjee (USA). One of the authors, Anjana Jajoo, is especially delighted to be a part of this tribute to professors Aro and Govindjee as she was lucky enough to have worked with both of them.
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Affiliation(s)
- Anjana Jajoo
- Photosynthesis Laboratory, School of Life Sciences, Devi Ahilya University, Indore, 452001, India.
| | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary.
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic.
| | - Suleyman I Allakhverdiev
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia.
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Devadasu E, Kanna SD, Neelam S, Yadav RM, Nama S, Akhtar P, Polgár TF, Ughy B, Garab G, Lambrev PH, Subramanyam R. Long- and short-term acclimation of the photosynthetic apparatus to salinity in Chlamydomonas reinhardtii. The role of Stt7 protein kinase. Front Plant Sci 2023; 14:1051711. [PMID: 37089643 PMCID: PMC10113551 DOI: 10.3389/fpls.2023.1051711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 03/03/2023] [Indexed: 05/03/2023]
Abstract
Salt stress triggers an Stt7-mediated LHCII-phosphorylation signaling mechanism similar to light-induced state transitions. However, phosphorylated LHCII, after detaching from PSII, does not attach to PSI but self-aggregates instead. Salt is a major stress factor in the growth of algae and plants. Here, our study mainly focuses on the organization of the photosynthetic apparatus to the long-term responses of Chlamydomonas reinhardtii to elevated NaCl concentrations. We analyzed the physiological effects of salt treatment at a cellular, membrane, and protein level by microscopy, protein profile analyses, transcripts, circular dichroism spectroscopy, chlorophyll fluorescence transients, and steady-state and time-resolved fluorescence spectroscopy. We have ascertained that cells that were grown in high-salinity medium form palmelloids sphere-shaped colonies, where daughter cells with curtailed flagella are enclosed within the mother cell walls. Palmelloid formation depends on the presence of a cell wall, as it was not observed in a cell-wall-less mutant CC-503. Using the stt7 mutant cells, we show Stt7 kinase-dependent phosphorylation of light-harvesting complex II (LHCII) in both short- and long-term treatments of various NaCl concentrations-demonstrating NaCl-induced state transitions that are similar to light-induced state transitions. The grana thylakoids were less appressed (with higher repeat distances), and cells grown in 150 mM NaCl showed disordered structures that formed diffuse boundaries with the flanking stroma lamellae. PSII core proteins were more prone to damage than PSI. At high salt concentrations (100-150 mM), LHCII aggregates accumulated in the thylakoid membranes. Low-temperature and time-resolved fluorescence spectroscopy indicated that the stt7 mutant was more sensitive to salt stress, suggesting that LHCII phosphorylation has a role in the acclimation and protection of the photosynthetic apparatus.
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Affiliation(s)
- Elsinraju Devadasu
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Sai Divya Kanna
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Satyabala Neelam
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Ranay Mohan Yadav
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Srilatha Nama
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Parveen Akhtar
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Tamás F. Polgár
- Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Theoretical Medicine Doctoral School, University of Szeged, Szeged, Hungary
| | - Bettina Ughy
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - Petar H. Lambrev
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, India
- *Correspondence: Rajagopal Subramanyam,
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Magyar M, Sipka G, Han W, Li X, Han G, Shen JR, Lambrev PH, Garab G. Characterization of the Rate-Limiting Steps in the Dark-To-Light Transitions of Closed Photosystem II: Temperature Dependence and Invariance of Waiting Times during Multiple Light Reactions. Int J Mol Sci 2022; 24:ijms24010094. [PMID: 36613535 PMCID: PMC9820552 DOI: 10.3390/ijms24010094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/09/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022] Open
Abstract
Rate-limiting steps in the dark-to-light transition of Photosystem II (PSII) were discovered by measuring the variable chlorophyll-a fluorescence transients elicited by single-turnover saturating flashes (STSFs). It was shown that in diuron-treated samples: (i) the first STSF, despite fully reducing the QA quinone acceptor molecule, generated only an F1(<Fm) fluorescence level; (ii) to produce the maximum (Fm) level, additional excitations were required, which, however, (iii) were effective only with sufficiently long Δτ waiting times between consecutive STSFs. Detailed studies revealed the gradual formation of the light-adapted charge-separated state, PSIIL. The data presented here substantiate this assignment: (i) the Δτ1/2 half-increment rise (or half-waiting) times of the diuron-treated isolated PSII core complexes (CCs) of Thermostichus vulcanus and spinach thylakoid membranes displayed similar temperature dependences between 5 and −80 °C, with substantially increased values at low temperatures; (ii) the Δτ1/2 values in PSII CC were essentially invariant on the Fk−to-Fk+1 (k = 1−4) increments both at 5 and at −80 °C, indicating the involvement of the same physical mechanism during the light-adaptation process of PSIIL. These data are in harmony with the earlier proposed role of dielectric relaxation processes in the formation of the light-adapted charge-separated state and in the variable chlorophyll-a fluorescence of PSII.
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Affiliation(s)
- Melinda Magyar
- Institute of Plant Biology, Biological Research Centre, 6726 Szeged, Hungary
| | - Gábor Sipka
- Institute of Plant Biology, Biological Research Centre, 6726 Szeged, Hungary
| | - Wenhui Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xingyue Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Petar H. Lambrev
- Institute of Plant Biology, Biological Research Centre, 6726 Szeged, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, 6726 Szeged, Hungary
- Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic
- Correspondence:
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Sipka G, Nagy L, Magyar M, Akhtar P, Shen JR, Holzwarth AR, Lambrev PH, Garab G. Light-induced reversible reorganizations in closed Type II reaction centre complexes: physiological roles and physical mechanisms. Open Biol 2022; 12:220297. [PMID: 36514981 PMCID: PMC9748786 DOI: 10.1098/rsob.220297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The purpose of this review is to outline our understanding of the nature, mechanism and physiological significance of light-induced reversible reorganizations in closed Type II reaction centre (RC) complexes. In the so-called 'closed' state, purple bacterial RC (bRC) and photosystem II (PSII) RC complexes are incapable of generating additional stable charge separation. Yet, upon continued excitation they display well-discernible changes in their photophysical and photochemical parameters. Substantial stabilization of their charge-separated states has been thoroughly documented-uncovering light-induced reorganizations in closed RCs and revealing their physiological importance in gradually optimizing the operation of the photosynthetic machinery during the dark-to-light transition. A range of subtle light-induced conformational changes has indeed been detected experimentally in different laboratories using different bRC and PSII-containing preparations. In general, the presently available data strongly suggest similar structural dynamics of closed bRC and PSII RC complexes, and similar physical mechanisms, in which dielectric relaxation processes and structural memory effects of proteins are proposed to play important roles.
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Affiliation(s)
- G. Sipka
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári körút 62, 6726 Szeged, Hungary
| | - L. Nagy
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári körút 62, 6726 Szeged, Hungary,Institute of Medical Physics and Informatics, University of Szeged, Rerrich B. tér 1, 6720 Szeged, Hungary
| | - M. Magyar
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári körút 62, 6726 Szeged, Hungary
| | - P. Akhtar
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári körút 62, 6726 Szeged, Hungary
| | - J.-R. Shen
- Institute of Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, 700-8530 Okayama, Japan,Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, People's Republic of China
| | - A. R. Holzwarth
- Max-Planck-Institute for Chemical Energy Conversion, 45470 Mülheim a.d. Ruhr, Germany
| | - P. H. Lambrev
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári körút 62, 6726 Szeged, Hungary
| | - G. Garab
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári körút 62, 6726 Szeged, Hungary,Department of Physics, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic
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Wang H, Qin H, Garab G, Gasanoff ES. Short-Chained Alcohols Make Membrane Surfaces Conducive for Melittin Action: Implication for the Physiological Role of Alcohols in Cells. Cells 2022; 11:cells11121928. [PMID: 35741057 PMCID: PMC9221640 DOI: 10.3390/cells11121928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/11/2022] [Accepted: 06/14/2022] [Indexed: 11/16/2022] Open
Abstract
Alcohols are a part of cellular metabolism, but their physiological roles are not well understood. We investigated the effects of short-chain alcohols on Daphnia pulex and model membranes mimicking the lipid composition of eukaryotic inner mitochondrial membranes. We also studied the synergistic effects of alcohols with the bee venom membrane-active peptide, melittin, which is structurally similar to endogenous membrane-active peptides. The alcohols, from ethanol to octanol, gradually decreased the heart rate and the mitochondrial ATP synthesis of daphnia; in contrast, in combination with melittin, which exerted no sizeable effect, they gradually increased both the heart rate and the ATP synthesis. Lipid packing and the order parameter of oriented films, monitored by EPR spectroscopy of the spin-labeled probe 5-doxylstrearic acid, revealed gradual alcohol-assisted bilayer to non-bilayer transitions in the presence of melittin; further, while the alcohols decreased, in combination with melittin they increased the order parameter of the film, which is attributed to the alcohol-facilitated association of melittin with the membrane. A 1H-NMR spectroscopy of the liposomes confirmed the enhanced induction of a non-bilayer lipid phase that formed around the melittin, without the permeabilization of the liposomal membrane. Our data suggest that short-chain alcohols, in combination with endogenous peptides, regulate protein functions via modulating the lipid polymorphism of membranes.
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Affiliation(s)
- Haoyu Wang
- STEM (Science, Technology, Engineering and Mathematics) Program, Science Department, Chaoyang KaiWen Academy, Beijing 100018, China; (H.W.); (H.Q.)
| | - Hao Qin
- STEM (Science, Technology, Engineering and Mathematics) Program, Science Department, Chaoyang KaiWen Academy, Beijing 100018, China; (H.W.); (H.Q.)
| | - Győző Garab
- Biological Research Centre, Eötvös Loránd Research Network, Temesvári krt. 62, H-6726 Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic
- Correspondence: (G.G.); (E.S.G.)
| | - Edward S. Gasanoff
- STEM (Science, Technology, Engineering and Mathematics) Program, Science Department, Chaoyang KaiWen Academy, Beijing 100018, China; (H.W.); (H.Q.)
- Belozersky Institute for Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
- Correspondence: (G.G.); (E.S.G.)
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11
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Akhtar P, Sipka G, Han W, Li X, Han G, Shen JR, Garab G, Tan HS, Lambrev PH. Ultrafast excitation quenching by the oxidized photosystem II reaction center. J Chem Phys 2022; 156:145101. [DOI: 10.1063/5.0086046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Photosystem II (PSII) is the pigment–protein complex driving the photoinduced oxidation of water and reduction of plastoquinone in all oxygenic photosynthetic organisms. Excitations in the antenna chlorophylls are photochemically trapped in the reaction center (RC) producing the chlorophyll–pheophytin radical ion pair P+ Pheo−. When electron donation from water is inhibited, the oxidized RC chlorophyll P+ acts as an excitation quencher, but knowledge on the kinetics of quenching is limited. Here, we used femtosecond transient absorption spectroscopy to compare the excitation dynamics of PSII with neutral and oxidized RC (P+). We find that equilibration in the core antenna has a major lifetime of about 300 fs, irrespective of the RC redox state. Two-dimensional electronic spectroscopy revealed additional slower energy equilibration occurring on timescales of 3–5 ps, concurrent with excitation trapping. The kinetics of PSII with open RC can be described well with previously proposed models according to which the radical pair P+ Pheo− is populated with a main lifetime of about 40 ps, which is primarily determined by energy transfer between the core antenna and the RC chlorophylls. Yet, in PSII with oxidized RC (P+), fast excitation quenching was observed with decay lifetimes as short as 3 ps and an average decay lifetime of about 90 ps, which is shorter than the excited-state lifetime of PSII with open RC. The underlying mechanism of this extremely fast quenching prompts further investigation.
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Affiliation(s)
- Parveen Akhtar
- School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, 637371, Singapore
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
- ELI-ALPS, ELI-HU Non-profit Ltd., Wolfgang Sandner u. 3, Szeged 6728, Hungary
| | - Gábor Sipka
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
| | - Wenhui Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xingyue Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Győző Garab
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
| | - Howe-Siang Tan
- School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, 637371, Singapore
| | - Petar H. Lambrev
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
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12
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Nagy G, Garab G. Neutron scattering in photosynthesis research: recent advances and perspectives for testing crop plants. Photosynth Res 2021; 150:41-49. [PMID: 32488447 PMCID: PMC8556207 DOI: 10.1007/s11120-020-00763-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/25/2020] [Indexed: 05/05/2023]
Abstract
The photosynthetic performance of crop plants under a variety of environmental factors and stress conditions, at the fundamental level, depends largely on the organization and structural flexibility of thylakoid membranes. These highly organized membranes accommodate virtually all protein complexes and additional compounds carrying out the light reactions of photosynthesis. Most regulatory mechanisms fine-tuning the photosynthetic functions affect the organization of thylakoid membranes at different levels of the structural complexity. In order to monitor these reorganizations, non-invasive techniques are of special value. On the mesoscopic scale, small-angle neutron scattering (SANS) has been shown to deliver statistically and spatially averaged information on the periodic organization of the thylakoid membranes in vivo and/or, in isolated thylakoids, under physiologically relevant conditions, without fixation or staining. More importantly, SANS investigations have revealed rapid reversible reorganizations on the timescale of several seconds and minutes. In this paper, we give a short introduction into the basics of SANS technique, advantages and limitations, and briefly overview recent advances and potential applications of this technique in the physiology and biotechnology of crop plants. We also discuss future perspectives of neutron crystallography and different neutron scattering techniques, which are anticipated to become more accessible and of more use in photosynthesis research at new facilities with higher fluxes and innovative instrumentation.
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Affiliation(s)
- Gergely Nagy
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, POB 49, 1525, Budapest, Hungary.
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, POB 521, 6701, Szeged, Hungary.
- Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, Ostrava - Slezská, 710 0, Ostrava, Czech Republic.
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13
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Dlouhý O, Karlický V, Arshad R, Zsiros O, Domonkos I, Kurasová I, Wacha AF, Morosinotto T, Bóta A, Kouřil R, Špunda V, Garab G. Lipid Polymorphism of the Subchloroplast-Granum and Stroma Thylakoid Membrane-Particles. II. Structure and Functions. Cells 2021; 10:2363. [PMID: 34572012 PMCID: PMC8472583 DOI: 10.3390/cells10092363] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/29/2021] [Accepted: 09/04/2021] [Indexed: 12/22/2022] Open
Abstract
In Part I, by using 31P-NMR spectroscopy, we have shown that isolated granum and stroma thylakoid membranes (TMs), in addition to the bilayer, display two isotropic phases and an inverted hexagonal (HII) phase; saturation transfer experiments and selective effects of lipase and thermal treatments have shown that these phases arise from distinct, yet interconnectable structural entities. To obtain information on the functional roles and origin of the different lipid phases, here we performed spectroscopic measurements and inspected the ultrastructure of these TM fragments. Circular dichroism, 77 K fluorescence emission spectroscopy, and variable chlorophyll-a fluorescence measurements revealed only minor lipase- or thermally induced changes in the photosynthetic machinery. Electrochromic absorbance transients showed that the TM fragments were re-sealed, and the vesicles largely retained their impermeabilities after lipase treatments-in line with the low susceptibility of the bilayer against the same treatment, as reflected by our 31P-NMR spectroscopy. Signatures of HII-phase could not be discerned with small-angle X-ray scattering-but traces of HII structures, without long-range order, were found by freeze-fracture electron microscopy (FF-EM) and cryo-electron tomography (CET). EM and CET images also revealed the presence of small vesicles and fusion of membrane particles, which might account for one of the isotropic phases. Interaction of VDE (violaxanthin de-epoxidase, detected by Western blot technique in both membrane fragments) with TM lipids might account for the other isotropic phase. In general, non-bilayer lipids are proposed to play role in the self-assembly of the highly organized yet dynamic TM network in chloroplasts.
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Affiliation(s)
- Ondřej Dlouhý
- Group of Biophysics, Department of Physics, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (O.D.); (V.K.); (I.K.); (V.Š.)
| | - Václav Karlický
- Group of Biophysics, Department of Physics, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (O.D.); (V.K.); (I.K.); (V.Š.)
- Laboratory of Ecological Plant Physiology, Domain of Environmental Effects on Terrestrial Ecosystems, Global Change Research Institute of the Czech Academy of Sciences, 603 00 Brno, Czech Republic
| | - Rameez Arshad
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic; (R.A.); (R.K.)
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700 AB Groningen, The Netherlands
| | - Ottó Zsiros
- Photosynthetic Membranes Group, Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, 6726 Szeged, Hungary; (O.Z.); (I.D.)
| | - Ildikó Domonkos
- Photosynthetic Membranes Group, Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, 6726 Szeged, Hungary; (O.Z.); (I.D.)
| | - Irena Kurasová
- Group of Biophysics, Department of Physics, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (O.D.); (V.K.); (I.K.); (V.Š.)
- Laboratory of Ecological Plant Physiology, Domain of Environmental Effects on Terrestrial Ecosystems, Global Change Research Institute of the Czech Academy of Sciences, 603 00 Brno, Czech Republic
| | - András F. Wacha
- Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network, 1117 Budapest, Hungary; (A.F.W.); (A.B.)
| | | | - Attila Bóta
- Institute of Materials and Environmental Chemistry, Eötvös Loránd Research Network, 1117 Budapest, Hungary; (A.F.W.); (A.B.)
| | - Roman Kouřil
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, 783 71 Olomouc, Czech Republic; (R.A.); (R.K.)
| | - Vladimír Špunda
- Group of Biophysics, Department of Physics, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (O.D.); (V.K.); (I.K.); (V.Š.)
- Laboratory of Ecological Plant Physiology, Domain of Environmental Effects on Terrestrial Ecosystems, Global Change Research Institute of the Czech Academy of Sciences, 603 00 Brno, Czech Republic
| | - Győző Garab
- Group of Biophysics, Department of Physics, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (O.D.); (V.K.); (I.K.); (V.Š.)
- Photosynthetic Membranes Group, Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, 6726 Szeged, Hungary; (O.Z.); (I.D.)
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14
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Karlický V, Kmecová Materová Z, Kurasová I, Nezval J, Štroch M, Garab G, Špunda V. Accumulation of geranylgeranylated chlorophylls in the pigment-protein complexes of Arabidopsis thaliana acclimated to green light: effects on the organization of light-harvesting complex II and photosystem II functions. Photosynth Res 2021; 149:233-252. [PMID: 33948813 PMCID: PMC8382614 DOI: 10.1007/s11120-021-00827-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Light quality significantly influences plant metabolism, growth and development. Recently, we have demonstrated that leaves of barley and other plant species grown under monochromatic green light (500-590 nm) accumulated a large pool of chlorophyll a (Chl a) intermediates with incomplete hydrogenation of their phytyl chains. In this work, we studied accumulation of these geranylgeranylated Chls a and b in pigment-protein complexes (PPCs) of Arabidopsis plants acclimated to green light and their structural-functional consequences on the photosynthetic apparatus. We found that geranylgeranylated Chls are present in all major PPCs, although their presence was more pronounced in light-harvesting complex II (LHCII) and less prominent in supercomplexes of photosystem II (PSII). Accumulation of geranylgeranylated Chls hampered the formation of PSII and PSI super- and megacomplexes in the thylakoid membranes as well as their assembly into chiral macrodomains; it also lowered the temperature stability of the PPCs, especially that of LHCII trimers, which led to their monomerization and an anomaly in the photoprotective mechanism of non-photochemical quenching. Role of geranylgeranylated Chls in adverse effects on photosynthetic apparatus of plants acclimated to green light is discussed.
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Affiliation(s)
- Václav Karlický
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic.
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic.
| | - Zuzana Kmecová Materová
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
| | - Irena Kurasová
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Jakub Nezval
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
| | - Michal Štroch
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Győző Garab
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic.
- Biological Research Center, Institute of Plant Biology, Temesvári körút 62, 6726, Szeged, Hungary.
| | - Vladimír Špunda
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic.
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic.
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15
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Sipka G, Magyar M, Mezzetti A, Akhtar P, Zhu Q, Xiao Y, Han G, Santabarbara S, Shen JR, Lambrev PH, Garab G. Light-adapted charge-separated state of photosystem II: structural and functional dynamics of the closed reaction center. Plant Cell 2021; 33:1286-1302. [PMID: 33793891 PMCID: PMC8225241 DOI: 10.1093/plcell/koab008] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/13/2020] [Indexed: 05/04/2023]
Abstract
Photosystem II (PSII) uses solar energy to oxidize water and delivers electrons for life on Earth. The photochemical reaction center of PSII is known to possess two stationary states. In the open state (PSIIO), the absorption of a single photon triggers electron-transfer steps, which convert PSII into the charge-separated closed state (PSIIC). Here, by using steady-state and time-resolved spectroscopic techniques on Spinacia oleracea and Thermosynechococcus vulcanus preparations, we show that additional illumination gradually transforms PSIIC into a light-adapted charge-separated state (PSIIL). The PSIIC-to-PSIIL transition, observed at all temperatures between 80 and 308 K, is responsible for a large part of the variable chlorophyll-a fluorescence (Fv) and is associated with subtle, dark-reversible reorganizations in the core complexes, protein conformational changes at noncryogenic temperatures, and marked variations in the rates of photochemical and photophysical reactions. The build-up of PSIIL requires a series of light-induced events generating rapidly recombining primary radical pairs, spaced by sufficient waiting times between these events-pointing to the roles of local electric-field transients and dielectric relaxation processes. We show that the maximum fluorescence level, Fm, is associated with PSIIL rather than with PSIIC, and thus the Fv/Fm parameter cannot be equated with the quantum efficiency of PSII photochemistry. Our findings resolve the controversies and explain the peculiar features of chlorophyll-a fluorescence kinetics, a tool to monitor the functional activity and the structural-functional plasticity of PSII in different wild-types and mutant organisms and under stress conditions.
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Affiliation(s)
- G�bor Sipka
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Melinda Magyar
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Alberto Mezzetti
- Universit� Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC) 91191 Gif-sur-Yvette, France
- Laboratoire de R�activit� de Surface UMR 7197, Sorbonne University, Paris, France
| | - Parveen Akhtar
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- ELI-ALPS, ELI-HU Nonprofit Ltd., Szeged, Hungary
| | - Qingjun Zhu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yanan Xiao
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Stefano Santabarbara
- Photosynthetic Research Unit, Institute of Biophysics, National Research Council of Italy, Milano, Italy
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Petar H Lambrev
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Author for correspondence: (G.G.), (P.H.L.)
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic
- Author for correspondence: (G.G.), (P.H.L.)
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16
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Ünnep R, Paul S, Zsiros O, Kovács L, Székely NK, Steinbach G, Appavou MS, Porcar L, Holzwarth AR, Garab G, Nagy G. Thylakoid membrane reorganizations revealed by small-angle neutron scattering of Monstera deliciosa leaves associated with non-photochemical quenching. Open Biol 2020; 10:200144. [PMID: 32931722 PMCID: PMC7536078 DOI: 10.1098/rsob.200144] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/14/2020] [Indexed: 12/14/2022] Open
Abstract
Non-photochemical quenching (NPQ) is an important photoprotective mechanism in plants and algae. Although the process is extensively studied, little is known about its relationship with ultrastructural changes of the thylakoid membranes. In order to better understand this relationship, we studied the effects of illumination on the organization of thylakoid membranes in Monstera deliciosa leaves. This evergreen species is known to exhibit very large NPQ and to possess giant grana with dozens of stacked thylakoids. It is thus ideally suited for small-angle neutron scattering measurements (SANS)-a non-invasive technique, which is capable of providing spatially and statistically averaged information on the periodicity of the thylakoid membranes and their rapid reorganizations in vivo. We show that NPQ-inducing illumination causes a strong decrease in the periodic order of granum thylakoid membranes. Development of NPQ and light-induced ultrastructural changes, as well as the relaxation processes, follow similar kinetic patterns. Surprisingly, whereas NPQ is suppressed by diuron, it impedes only the relaxation of the structural changes and not its formation, suggesting that structural changes do not cause but enable NPQ. We also demonstrate that the diminishment of SANS peak does not originate from light-induced redistribution and reorientation of chloroplasts inside the cells.
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Affiliation(s)
- Renáta Ünnep
- Neutron Spectroscopy Department, Centre for Energy Research, H-1121 Budapest, Konkoly-Thege Miklós út 29-33, Hungary
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Suman Paul
- Max-Planck-Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim a.d. Ruhr, Germany
| | - Ottó Zsiros
- Biological Research Centre, Institute of Plant Biology, 6726 Szeged, Hungary
| | - László Kovács
- Biological Research Centre, Institute of Plant Biology, 6726 Szeged, Hungary
| | - Noémi K. Székely
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, 85748 Garching, Germany
| | - Gábor Steinbach
- Biological Research Centre, Institute of Biophysics, Temesvári körút 62, 6726 Szeged, Hungary
| | - Marie-Sousai Appavou
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, 85748 Garching, Germany
| | - Lionel Porcar
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - Alfred R. Holzwarth
- Max-Planck-Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim a.d. Ruhr, Germany
| | - Győző Garab
- Biological Research Centre, Institute of Plant Biology, 6726 Szeged, Hungary
- Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Gergely Nagy
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- European Spallation Source ESS ERIC, PO Box 176, 221 00 Lund, Sweden
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, 1121 Budapest, Hungary
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17
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Dlouhý O, Kurasová I, Karlický V, Javornik U, Šket P, Petrova NZ, Krumova SB, Plavec J, Ughy B, Špunda V, Garab G. Modulation of non-bilayer lipid phases and the structure and functions of thylakoid membranes: effects on the water-soluble enzyme violaxanthin de-epoxidase. Sci Rep 2020; 10:11959. [PMID: 32686730 PMCID: PMC7371714 DOI: 10.1038/s41598-020-68854-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/26/2020] [Indexed: 12/19/2022] Open
Abstract
The role of non-bilayer lipids and non-lamellar lipid phases in biological membranes is an enigmatic problem of membrane biology. Non-bilayer lipids are present in large amounts in all membranes; in energy-converting membranes they constitute about half of their total lipid content—yet their functional state is a bilayer. In vitro experiments revealed that the functioning of the water-soluble violaxanthin de-epoxidase (VDE) enzyme of plant thylakoids requires the presence of a non-bilayer lipid phase. 31P-NMR spectroscopy has provided evidence on lipid polymorphism in functional thylakoid membranes. Here we reveal reversible pH- and temperature-dependent changes of the lipid-phase behaviour, particularly the flexibility of isotropic non-lamellar phases, of isolated spinach thylakoids. These reorganizations are accompanied by changes in the permeability and thermodynamic parameters of the membranes and appear to control the activity of VDE and the photoprotective mechanism of non-photochemical quenching of chlorophyll-a fluorescence. The data demonstrate, for the first time in native membranes, the modulation of the activity of a water-soluble enzyme by a non-bilayer lipid phase.
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Affiliation(s)
- Ondřej Dlouhý
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Irena Kurasová
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic.,Global Change Research Institute, Czech Academy of Sciences, Brno, Czech Republic
| | - Václav Karlický
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic.,Global Change Research Institute, Czech Academy of Sciences, Brno, Czech Republic
| | - Uroš Javornik
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia
| | - Primož Šket
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia.,EN-FIST Center of Excellence, Ljubljana, Slovenia
| | - Nia Z Petrova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Sashka B Krumova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia.,EN-FIST Center of Excellence, Ljubljana, Slovenia.,Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Bettina Ughy
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic. .,Institute of Plant Biology, Biological Research Centre, Szeged, Hungary.
| | - Vladimír Špunda
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic. .,Global Change Research Institute, Czech Academy of Sciences, Brno, Czech Republic.
| | - Győző Garab
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic. .,Institute of Plant Biology, Biological Research Centre, Szeged, Hungary.
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18
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Zsiros O, Nagy G, Patai R, Solymosi K, Gasser U, Polgár TF, Garab G, Kovács L, Hörcsik ZT. Similarities and Differences in the Effects of Toxic Concentrations of Cadmium and Chromium on the Structure and Functions of Thylakoid Membranes in Chlorella variabilis. Front Plant Sci 2020; 11:1006. [PMID: 32733513 PMCID: PMC7358611 DOI: 10.3389/fpls.2020.01006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/19/2020] [Indexed: 05/26/2023]
Abstract
Trace metal contaminations in natural waters, wetlands, and wastewaters pose serious threats to aquatic ecosystems-mainly via targeting microalgae. In this work, we investigated the effects of toxic amounts of chromium and cadmium ions on the structure and function of the photosynthetic machinery of Chlorella variabilis cells. To halt the propagation of cells, we used high concentrations of Cd and Cr, 50-50 mg L-1, in the forms of CdCl2 x 2.5 H2O and K2Cr2O7, respectively. Both treatments led to similar, about 50% gradual diminishment of the chlorophyll contents of the cells in 48 h, which was, however, accompanied by a small (~10%) but statistically significant enrichment (Cd) and loss (Cr) of ß-carotene. Both Cd and Cr inhibited the activity of photosystem II (PSII)-but with more severe inhibitions with Cr. On the contrary, the PsbA (D1) protein of PSII and the PsbO protein of the oxygen-evolving complex were retained more in Cr-treated cells than in the presence of Cd. These data and the higher susceptibility of P700 redox transients in Cr-treated cells suggest that, unlike with Cd, PSII is not the main target in the photochemical apparatus. These differences at the level of photochemistry also brought about dissimilarities at higher levels of the structural complexity of the photosynthetic apparatus. Circular dichroism (CD) spectroscopy measurements revealed moderate perturbations in the macro-organization of the protein complexes-with more pronounced decline in Cd-treated cells than in the cells with Cr. Also, as reflected by transmission electron microscopy and small-angle neutron scattering, the thylakoid membranes suffered shrinking and were largely fragmented in Cd-treated cells, whereas no changes could be discerned with Cr. The preservation of integrity of membranes in Cr-treated cells was most probably aided by high proportion of the de-epoxidized xanthophylls, which were absent with Cd. It can thus be concluded that beside strong similarities of the toxic effects of Cr and Cd, the response of the photosynthetic machinery of C. variabilis to these two trace metal ions substantially differ from each other-strongly suggesting different inhibitory and protective mechanisms following the primary toxic events.
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Affiliation(s)
- Ottó Zsiros
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Gergely Nagy
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Villigen, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Budapest, Hungary
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Roland Patai
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Katalin Solymosi
- Department of Plant Anatomy, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Urs Gasser
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Villigen, Switzerland
| | - Tamás F. Polgár
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Zsolt Tibor Hörcsik
- Department of Biology Nyíregyháza, Institute of Environmental Sciences, University of Nyíregyháza, Nyíregyháza, Hungary
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19
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Akhtar P, Nowakowski PJ, Wang W, Do TN, Zhao S, Siligardi G, Garab G, Shen JR, Tan HS, Lambrev PH. Spectral tuning of light-harvesting complex II in the siphonous alga Bryopsis corticulans and its effect on energy transfer dynamics. Biochim Biophys Acta Bioenerg 2020; 1861:148191. [PMID: 32201306 DOI: 10.1016/j.bbabio.2020.148191] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 03/11/2020] [Accepted: 03/13/2020] [Indexed: 12/17/2022]
Abstract
Light-harvesting complex II (LHCII) from the marine green macroalga Bryopsis corticulans is spectroscopically characterized to understand the structural and functional changes resulting from adaptation to intertidal environment. LHCII is homologous to its counterpart in land plants but has a different carotenoid and chlorophyll (Chl) composition. This is reflected in the steady-state absorption, fluorescence, linear dichroism, circular dichroism and anisotropic circular dichroism spectra. Time-resolved fluorescence and two-dimensional electronic spectroscopy were used to investigate the consequences of this adaptive change in the pigment composition on the excited-state dynamics. The complex contains additional Chl b spectral forms - absorbing at around 650 nm and 658 nm - and lacks the red-most Chl a forms compared with higher-plant LHCII. Similar to plant LHCII, energy transfer between Chls occurs on timescales from under hundred fs (mainly from Chl b to Chl a) to several picoseconds (mainly between Chl a pools). However, the presence of long-lived, weakly coupled Chl b and Chl a states leads to slower exciton equilibration in LHCII from B. corticulans. The finding demonstrates a trade-off between the enhanced absorption of blue-green light and the excitation migration time. However, the adaptive change does not result in a significant drop in the overall photochemical efficiency of Photosystem II. These results show that LHCII is a robust adaptable system whose spectral properties can be tuned to the environment for optimal light harvesting.
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Affiliation(s)
- Parveen Akhtar
- Biological Research Centre, Szeged, Hungary; ELI-ALPS, ELI Nonprofit Ltd., Szeged, Hungary
| | - Paweł J Nowakowski
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore
| | - Wenda Wang
- Photosynthesis Research Centre, Chinese Academy of Sciences, Beijing, China
| | - Thanh Nhut Do
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore
| | - Songhao Zhao
- Photosynthesis Research Centre, Chinese Academy of Sciences, Beijing, China
| | - Giuliano Siligardi
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Győző Garab
- Biological Research Centre, Szeged, Hungary; Department of Physics, Faculty of Science, University of Ostrava, Czech Republic
| | - Jian-Ren Shen
- Photosynthesis Research Centre, Chinese Academy of Sciences, Beijing, China; Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
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20
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Zsiros O, Ünnep R, Nagy G, Almásy L, Patai R, Székely NK, Kohlbrecher J, Garab G, Dér A, Kovács L. Role of Protein-Water Interface in the Stacking Interactions of Granum Thylakoid Membranes-As Revealed by the Effects of Hofmeister Salts. Front Plant Sci 2020; 11:1257. [PMID: 32922427 PMCID: PMC7456932 DOI: 10.3389/fpls.2020.01257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/30/2020] [Indexed: 05/08/2023]
Abstract
The thylakoid membranes of vascular plants are differentiated into stacked granum and unstacked stroma regions. The formation of grana is triggered by the macrodomain formation of photosystem II and light-harvesting complex II (PSII-LHCII) and thus their lateral segregation from the photosystem I-light-harvesting complex I (PSI-LHCI) super-complexes and the ATP-synthase; which is then stabilized by stacking interactions of the adjacent PSII-LHCII enriched regions of the thylakoid membranes. The self-assembly and dynamics of this highly organized membrane system and the nature of forces acting between the PSII-LHCII macrodomains are not well understood. By using circular dichroism (CD) spectroscopy, small-angle neutron scattering (SANS) and transmission electron microscopy (TEM), we investigated the effects of Hofmeister salts on the organization of pigment-protein complexes and on the ultrastructure of thylakoid membranes. We found that the kosmotropic agent (NH4)2SO4 and the Hofmeister-neutral NaCl, up to 2 M concentrations, hardly affected the macro-organization of the protein complexes and the membrane ultrastructure. In contrast, chaotropic salts, NaClO4, and NaSCN destroyed the mesoscopic structures, the multilamellar organization of the thylakoid membranes and the chiral macrodomains of the protein complexes but without noticeably affecting the short-range, pigment-pigment excitonic interactions. Comparison of the concentration- and time-dependences of SANS, TEM and CD parameters revealed the main steps of the disassembly of grana in the presence of chaotropes. It begins with a rapid diminishment of the long-range periodic order of the grana membranes, apparently due to an increased stacking disorder of the thylakoid membranes, as reflected by SANS experiments. SANS measurements also allowed discrimination between the cationic and anionic effects-in stacking and disorder, respectively. This step is followed by a somewhat slower disorganization of the TEM ultrastructure, due to the gradual loss of stacked membrane pairs. Occurring last is the stepwise decrease and disappearance of the long-range chiral order of the protein complexes, the rate of which was faster in LHCII-deficient membranes. These data are interpreted in terms of a theory, from our laboratory, according to which Hofmeister salts primarily affect the hydrophylic-hydrophobic interactions of proteins, and the stroma-exposed regions of the intrinsic membrane proteins, in particular-pointing to the role of protein-water interface in the stacking interactions of granum thylakoid membranes.
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Affiliation(s)
- Ottó Zsiros
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Renáta Ünnep
- Neutron Spectroscopy Department, Centre for Energy Research, Budapest, Hungary
| | - Gergely Nagy
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Budapest, Hungary
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - László Almásy
- Neutron Spectroscopy Department, Centre for Energy Research, Budapest, Hungary
| | - Roland Patai
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Noémi K. Székely
- Jülich Centre for Neutron Science at MLZ, Forschungszentrum Jülich GmbH, Garching, Germany
| | - Joachim Kohlbrecher
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czechia
- *Correspondence: Győző Garab, ; András Dér, ; László Kovács,
| | - András Dér
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
- *Correspondence: Győző Garab, ; András Dér, ; László Kovács,
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- *Correspondence: Győző Garab, ; András Dér, ; László Kovács,
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21
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Akhtar P, Görföl F, Garab G, Lambrev PH. Dependence of chlorophyll fluorescence quenching on the lipid-to-protein ratio in reconstituted light-harvesting complex II membranes containing lipid labels. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.03.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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22
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Ughy B, Karlický V, Dlouhý O, Javornik U, Materová Z, Zsiros O, Šket P, Plavec J, Špunda V, Garab G. Lipid-polymorphism of plant thylakoid membranes. Enhanced non-bilayer lipid phases associated with increased membrane permeability. Physiol Plant 2019; 166:278-287. [PMID: 30666653 DOI: 10.1111/ppl.12929] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/17/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Earlier experiments, using 31 P-NMR and time-resolved merocyanine fluorescence spectroscopy, have shown that isolated intact, fully functional plant thylakoid membranes, in addition to the bilayer phase, contain three non-bilayer (or non-lamellar) lipid phases. It has also been shown that the lipid polymorphism of thylakoid membranes can be characterized by remarkable plasticity, i.e. by significant variations in 31 P-NMR signatures. However, changes in the lipid-phase behaviour of thylakoids could not be assigned to changes in the overall membrane organization and the photosynthetic activity, as tested by circular dichroism and 77 K fluorescence emission spectroscopy and the magnitude of the variable fluorescence of photosystem II, which all showed only marginal variations. In this work, we investigated in more detail the temporal stability of the different lipid phases by recording 31 P-NMR spectra on isolated thylakoid membranes that were suspended in sorbitol- or NaCl-based media. We observed, at 5°C during 8 h in the dark, substantial gradual enhancement of the isotropic lipid phases and diminishment of the bilayer phase in the sorbitol-based medium. These changes compared well with the gradually increasing membrane permeability, as testified by the gradual acceleration of the decay of flash-induced electrochromic absorption changes and characteristic changes in the kinetics of fast chlorophyll a-fluorescence transients; all variations were much less pronounced in the NaCl-based medium. These observations suggest that non-bilayer lipids and non-lamellar lipid phases play significant roles in the structural dynamics and functional plasticity of thylakoid membranes.
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Affiliation(s)
- Bettina Ughy
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | - Václav Karlický
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava CZ-710 00, Czech Republic
- Global Change Research Institute, Czech Academy of Sciences, Brno 603 00, Czech Republic
| | - Ondřej Dlouhý
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava CZ-710 00, Czech Republic
| | - Uroš Javornik
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia
| | - Zuzana Materová
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava CZ-710 00, Czech Republic
| | - Ottó Zsiros
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged H-6726, Hungary
| | - Primož Šket
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia
- EN-FIST Center of Excellence, Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Ljubljana, Slovenia
- EN-FIST Center of Excellence, Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, Ljubljana, Slovenia
| | - Vladimír Špunda
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava CZ-710 00, Czech Republic
- Global Change Research Institute, Czech Academy of Sciences, Brno 603 00, Czech Republic
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged H-6726, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava CZ-710 00, Czech Republic
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23
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Sipka G, Müller P, Brettel K, Magyar M, Kovács L, Zhu Q, Xiao Y, Han G, Lambrev PH, Shen JR, Garab G. Redox transients of P680 associated with the incremental chlorophyll-a fluorescence yield rises elicited by a series of saturating flashes in diuron-treated photosystem II core complex of Thermosynechococcus vulcanus. Physiol Plant 2019; 166:22-32. [PMID: 30790299 DOI: 10.1111/ppl.12945] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 02/14/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
Recent chlorophyll-a fluorescence yield measurements, using single-turnover saturating flashes (STSFs), have revealed the involvement of a rate-limiting step in the reactions following the charge separation induced by the first flash. As also shown here, in diuron-inhibited PSII core complexes isolated from Thermosynechococcus vulcanus the fluorescence maximum could only be reached by a train of STSFs. In order to elucidate the origin of the fluorescence yield increments in STSF series, we performed transient absorption measurements at 819 nm, reflecting the photooxidation and re-reduction kinetics of the primary electron donor P680. Upon single flash excitation of the dark-adapted sample, the decay kinetics could be described with lifetimes of 17 ns (∼50%) and 167 ns (∼30%), and a longer-lived component (∼20%). This kinetics are attributed to re-reduction of P680•+ by the donor side of PSII. In contrast, upon second-flash (with Δt between 5 μs and 100 ms) or repetitive excitation, the 819 nm absorption changes decayed with lifetimes of about 2 ns (∼60%) and 10 ns (∼30%), attributed to recombination of the primary radical pair P680•+ Pheo•- , and a small longer-lived component (∼10%). These data confirm that only the first STSF is capable of generating stable charge separation - leading to the reduction of QA ; and thus, the fluorescence yield increments elicited by the consecutive flashes must have a different physical origin. Our double-flash experiments indicate that the rate-limiting steps, detected by chlorophyll-a fluorescence, are not correlated with the turnover of P680.
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Affiliation(s)
- Gábor Sipka
- Institute of Plant Biology, Laboratory of Photosynthetic Membranes, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Pavel Müller
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Klaus Brettel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Melinda Magyar
- Institute of Plant Biology, Laboratory of Photosynthetic Membranes, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - László Kovács
- Institute of Plant Biology, Laboratory of Photosynthetic Membranes, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Qingjun Zhu
- Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yanan Xiao
- Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guangye Han
- Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Petar H Lambrev
- Institute of Plant Biology, Laboratory of Photosynthetic Membranes, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Jian-Ren Shen
- Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Photosynthesis Research Center, Okayama University, Okayama, Japan
| | - Győző Garab
- Institute of Plant Biology, Laboratory of Photosynthetic Membranes, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic
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24
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Zsiros O, Nagy V, Párducz Á, Nagy G, Ünnep R, El-Ramady H, Prokisch J, Lisztes-Szabó Z, Fári M, Csajbók J, Tóth SZ, Garab G, Domokos-Szabolcsy É. Effects of selenate and red Se-nanoparticles on the photosynthetic apparatus of Nicotiana tabacum. Photosynth Res 2019; 139:449-460. [PMID: 30374728 DOI: 10.1007/s11120-018-0599-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 10/17/2018] [Indexed: 05/24/2023]
Abstract
Selenium (Se) is a natural trace element, which shifts its action in a relatively narrow concentration range from nutritional role to toxicity. Although it has been well established that in plants chloroplasts are among the primary targets, the mechanism of toxicity on photosynthesis is not well understood. Here, we compared selenate and red-allotrope elemental selenium nanoparticles (red nanoSe) in in vitro tobacco cultures to investigate their effects on the structure and functions of the photosynthetic machinery. Selenate at 10 mg/L concentration retarded plant growth; it also led to a decreased chlorophyll content, accompanied with an increase in the carotenoid-to-chlorophyll ratio. Structural examinations of the photosynthetic machinery, using electron microscopy, small-angle neutron scattering and circular dichroism spectroscopy, revealed significant perturbation in the macro-organization of the pigment-protein complexes and sizeable shrinkage in the repeat distance of granum thylakoid membranes. As shown by chlorophyll a fluorescence transient measurements, these changes in the ultrastructure were associated with a significantly diminished photosystem II activity and a reduced performance of the photosynthetic electron transport, and an enhanced capability of non-photochemical quenching. These changes in the structure and function of the photosynthetic apparatus explain, at least in part, the retarded growth of plantlets in the presence of 10 mg/L selenate. In contrast, red nanoSe, even at 100 mg/L and selenate at 1 mg/L, exerted no negative effect on the growth of plantlets and affected only marginally the thylakoid membrane ultrastructure and the photosynthetic functions.
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Affiliation(s)
- Ottó Zsiros
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, Szeged, 6701, Hungary
| | - Valéria Nagy
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, Szeged, 6701, Hungary
| | - Árpád Párducz
- Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, POB 521, Szeged, 6701, Hungary
| | - Gergely Nagy
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, Szeged, 6701, Hungary
- Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, Budapest, 1525, Hungary
| | - Renáta Ünnep
- Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, Budapest, 1525, Hungary
| | - Hassan El-Ramady
- Department of Soil and Water Sciences, Faculty of Agriculture, Kafrelsheikh Uni, 33516, Kafr El-Sheikh, Egypt
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, Egyetem ter 1, Debrecen, 4032, Hungary
| | - József Prokisch
- Bio- and Environmental Enegetics Inst., Nano Food Lab, Debrecen University, Boszormenyi 138, Debrecen, 4032, Hungary
| | - Zsuzsa Lisztes-Szabó
- Isotope Climatology and Environmental Research Centre, Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, 4026, Hungary
| | - Miklós Fári
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, Egyetem ter 1, Debrecen, 4032, Hungary
| | - József Csajbók
- Department of Crop Production and Applied Ecology, University of Debrecen, Boszormenyi 138, Debrecen, 4032, Hungary
| | - Szilvia Zita Tóth
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, Szeged, 6701, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, Szeged, 6701, Hungary
- Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, 710 0, Ostrava - Slezská Ostrava, Czech Republic
| | - Éva Domokos-Szabolcsy
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, Egyetem ter 1, Debrecen, 4032, Hungary.
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25
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Akhtar P, Lindorfer D, Lingvay M, Pawlak K, Zsiros O, Siligardi G, Jávorfi T, Dorogi M, Ughy B, Garab G, Renger T, Lambrev PH. Anisotropic Circular Dichroism of Light-Harvesting Complex II in Oriented Lipid Bilayers: Theory Meets Experiment. J Phys Chem B 2019; 123:1090-1098. [PMID: 30604975 DOI: 10.1021/acs.jpcb.8b12474] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Anisotropic circular dichroism (ACD) spectroscopy of macroscopically aligned molecules reveals additional information about their excited states that is lost in the CD of randomly oriented solutions. ACD spectra of light-harvesting complex II (LHCII)-the main peripheral antenna of photosystem II in plants-in oriented lipid bilayers were recorded from the far-UV to the visible wavelength region. ACD spectra show a drastically enhanced magnitude and level of detail compared to the isotropic CD spectra, resolving a greater number of bands and weak optical transitions. Exciton calculations show that the spectral features in the chlorophyll Q y region are well-reproduced by an existing Hamiltonian for LHCII, providing further evidence for the identity of energy sinks at chlorophylls a603 and a610 in the stromal layer and chlorophylls a604 and a613 in the luminal layer. We propose ACD spectroscopy to be a valuable tool linking the three-dimensional structure and the photophysical properties of pigment-protein complexes.
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Affiliation(s)
- Parveen Akhtar
- Biological Research Centre , Hungarian Academy of Sciences , Temesvári krt. 62 , 6726 Szeged , Hungary.,ELI-ALPS, ELI-HU Nonprofit Ltd. , Budapesti út 5 , 6728 Szeged , Hungary
| | - Dominik Lindorfer
- Institute for Theoretical Physics , Johannes Kepler University Linz , Altenberger Str. 69 , 4040 Linz , Austria
| | - Mónika Lingvay
- Biological Research Centre , Hungarian Academy of Sciences , Temesvári krt. 62 , 6726 Szeged , Hungary.,Faculty of Science and Informatics, Doctoral School of Physics , University of Szeged , Dóm tér 9 , 6720 Szeged , Hungary
| | - Krzysztof Pawlak
- Biological Research Centre , Hungarian Academy of Sciences , Temesvári krt. 62 , 6726 Szeged , Hungary
| | - Ottó Zsiros
- Biological Research Centre , Hungarian Academy of Sciences , Temesvári krt. 62 , 6726 Szeged , Hungary
| | - Giuliano Siligardi
- Diamond Light Source Ltd. , Harwell Science and Innovation Campus , Didcot , Oxfordshire OX11 0DE , U.K
| | - Tamás Jávorfi
- Diamond Light Source Ltd. , Harwell Science and Innovation Campus , Didcot , Oxfordshire OX11 0DE , U.K
| | - Márta Dorogi
- Biological Research Centre , Hungarian Academy of Sciences , Temesvári krt. 62 , 6726 Szeged , Hungary
| | - Bettina Ughy
- Biological Research Centre , Hungarian Academy of Sciences , Temesvári krt. 62 , 6726 Szeged , Hungary
| | - Győző Garab
- Biological Research Centre , Hungarian Academy of Sciences , Temesvári krt. 62 , 6726 Szeged , Hungary.,Faculty of Science, Department of Physics , University of Ostrava , Chittussiho 10 , 710 00 Ostrava , Czech Republic
| | - Thomas Renger
- Institute for Theoretical Physics , Johannes Kepler University Linz , Altenberger Str. 69 , 4040 Linz , Austria
| | - Petar H Lambrev
- Biological Research Centre , Hungarian Academy of Sciences , Temesvári krt. 62 , 6726 Szeged , Hungary
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26
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Domokos-Szabolcsy É, Fári M, Márton L, Czakó M, Veres S, Elhawat N, Antal G, El-Ramady H, Zsíros O, Garab G, Alshaal T. Selenate tolerance and selenium hyperaccumulation in the monocot giant reed (Arundo donax), a biomass crop plant with phytoremediation potential. Environ Sci Pollut Res Int 2018; 25:31368-31380. [PMID: 30196460 DOI: 10.1007/s11356-018-3127-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 09/03/2018] [Indexed: 06/08/2023]
Abstract
The response of giant reed (Arundo donax L.) to selenium (Se), added as selenate, was studied. The development, stress response, uptake, translocation, and accumulation of Se were documented in three giant reed ecotypes STM (Hungary), BL (USA), and ESP (Spain), representing different climatic zones. Plantlets regenerated from sterile tissue cultures were grown under greenhouse conditions in sand supplemented with 0, 2.5, 5, and 10 mg Se kg-1 added as sodium selenate. Total Se content was measured in different plant parts using hydride generation atomic fluorescence spectroscopy. All plants developed normally in the 0-5.0 mg Se kg-1 concentration range regardless of ecotype, but no growth occurred at 10.0 mg Se kg-1. There were no signs of chlorosis or necrosis, and the photosynthetic machinery was not affected as evidenced by no marked differences in the structure of thylakoid membranes. There was no change in the maximum quantum yield of photosystem II (Fv/Fm ratio) in the three ecotypes under Se stress, except for a significant negative effect in the ESP ecotype in the 5.0 mg Se kg-1 treatment. Glutathione peroxidase (GPx) activity increased as the Se concentration increased in the growth medium. GPx activity was higher in the shoot system than the root system in all Se treatments. All ecotypes showed great capacity of take up, translocate and accumulate selenium in their stem and leaf. Relative Se accumulation is best described as leaf ˃˃ stem ˃ root. The ESP ecotype accumulated 1783 μg g-1 in leaf, followed by BL with 1769 μg g-1, and STM with 1606 μg g-1 in the 5.0 mg Se kg-1 treatment. All ecotypes showed high values of translocation and bioaccumulation factors, particularly the ESP ecotype (10.1 and 689, respectively, at the highest tolerated Se supplementation level). Based on these findings, Arundo donax has been identified as the first monocot hyperaccumulator of selenium, because Se concentration in the leaves of all three ecotypes, and also in the stem of the ESP ecotype, is higher than 0.1% (dry weight basis) under the conditions tested. Tolerance up to 5.0 mg Se kg-1 and the Se hyperaccumulation capacity make giant reed a promising tool for Se phytoremediation.
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Affiliation(s)
- Éva Domokos-Szabolcsy
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, AGTC Böszörményi ut 138, Debrecen, 4032, Hungary
| | - Miklós Fári
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, AGTC Böszörményi ut 138, Debrecen, 4032, Hungary
| | - László Márton
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Mihály Czakó
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Szilvia Veres
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, AGTC Böszörményi ut 138, Debrecen, 4032, Hungary
| | - Nevien Elhawat
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, AGTC Böszörményi ut 138, Debrecen, 4032, Hungary
- Faculty of Home Economic, Department of Biological and Environmental Sciences, Al-Azhar University, Cairo, Egypt
| | - Gabriella Antal
- Faculty of Economics and Business, Institute of Sectoral Economics and Methodology, University of Debrecen, Debrecen, Hungary
| | - Hassan El-Ramady
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, AGTC Böszörményi ut 138, Debrecen, 4032, Hungary
- Soil and Water Department, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh, 33516, Egypt
| | - Ottó Zsíros
- Biological Research Center, Hungarian Academy of Sciences, Institute of Plant Biology, POB 521, Szeged, H-6701, Hungary
| | - Győző Garab
- Biological Research Center, Hungarian Academy of Sciences, Institute of Plant Biology, POB 521, Szeged, H-6701, Hungary
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Tarek Alshaal
- Department of Agricultural Botany, Plant Physiology and Biotechnology, University of Debrecen, AGTC Böszörményi ut 138, Debrecen, 4032, Hungary.
- Soil and Water Department, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh, 33516, Egypt.
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Patty CHL, Luo DA, Snik F, Ariese F, Buma WJ, Ten Kate IL, van Spanning RJM, Sparks WB, Germer TA, Garab G, Kudenov MW. Imaging linear and circular polarization features in leaves with complete Mueller matrix polarimetry. Biochim Biophys Acta Gen Subj 2018. [PMID: 29526506 DOI: 10.1016/j.bbagen.2018.03.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Spectropolarimetry of intact plant leaves allows to probe the molecular architecture of vegetation photosynthesis in a non-invasive and non-destructive way and, as such, can offer a wealth of physiological information. In addition to the molecular signals due to the photosynthetic machinery, the cell structure and its arrangement within a leaf can create and modify polarization signals. Using Mueller matrix polarimetry with rotating retarder modulation, we have visualized spatial variations in polarization in transmission around the chlorophyll a absorbance band from 650 nm to 710 nm. We show linear and circular polarization measurements of maple leaves and cultivated maize leaves and discuss the corresponding Mueller matrices and the Mueller matrix decompositions, which show distinct features in diattenuation, polarizance, retardance and depolarization. Importantly, while normal leaf tissue shows a typical split signal with both a negative and a positive peak in the induced fractional circular polarization and circular dichroism, the signals close to the veins only display a negative band. The results are similar to the negative band as reported earlier for single macrodomains. We discuss the possible role of the chloroplast orientation around the veins as a cause of this phenomenon. Systematic artefacts are ruled out as three independent measurements by different instruments gave similar results. These results provide better insight into circular polarization measurements on whole leaves and options for vegetation remote sensing using circular polarization.
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Affiliation(s)
- C H Lucas Patty
- Molecular Cell Physiology, VU Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
| | - David A Luo
- Optical Sensing Lab, Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Frans Snik
- Leiden Observatory, Leiden University, P.O. Box 9513, Leiden 2300 RA, The Netherlands
| | - Freek Ariese
- LaserLaB, VU Amsterdam, De Boelelaan 1083, Amsterdam 1081 HV, The Netherlands
| | - Wybren Jan Buma
- HIMS, Photonics Group, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Inge Loes Ten Kate
- Department of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht 3584 CD, The Netherlands
| | - Rob J M van Spanning
- Systems Bioinformatics, VU Amsterdam, De Boelelaan 1108, Amsterdam 1081 HZ, The Netherlands
| | - William B Sparks
- Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
| | - Thomas A Germer
- Senior Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, P.O. Box 521, Szeged H-6701, Hungary; Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, Slezská Ostrava, Czech Republic
| | - Michael W Kudenov
- Optical Sensing Lab, Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC 27695, USA
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Magyar M, Sipka G, Kovács L, Ughy B, Zhu Q, Han G, Špunda V, Lambrev PH, Shen JR, Garab G. Rate-limiting steps in the dark-to-light transition of Photosystem II - revealed by chlorophyll-a fluorescence induction. Sci Rep 2018; 8:2755. [PMID: 29426901 DOI: 10.1038/s41598-41018-21195-41592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 01/31/2018] [Indexed: 05/28/2023] Open
Abstract
Photosystem II (PSII) catalyses the photoinduced oxygen evolution and, by producing reducing equivalents drives, in concert with PSI, the conversion of carbon dioxide to sugars. Our knowledge about the architecture of the reaction centre (RC) complex and the mechanisms of charge separation and stabilisation is well advanced. However, our understanding of the processes associated with the functioning of RC is incomplete: the photochemical activity of PSII is routinely monitored by chlorophyll-a fluorescence induction but the presently available data are not free of controversy. In this work, we examined the nature of gradual fluorescence rise of PSII elicited by trains of single-turnover saturating flashes (STSFs) in the presence of a PSII inhibitor, permitting only one stable charge separation. We show that a substantial part of the fluorescence rise originates from light-induced processes that occur after the stabilisation of charge separation, induced by the first STSF; the temperature-dependent relaxation characteristics suggest the involvement of conformational changes in the additional rise. In experiments using double flashes with variable waiting times (∆τ) between them, we found that no rise could be induced with zero or short ∆τ, the value of which depended on the temperature - revealing a previously unknown rate-limiting step in PSII.
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Affiliation(s)
- Melinda Magyar
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - Gábor Sipka
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - Bettina Ughy
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - Qingjun Zhu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany the Chinese Academy of Sciences, Beijing, 100093, China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany the Chinese Academy of Sciences, Beijing, 100093, China
| | - Vladimír Špunda
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, CZ-710 00, Ostrava, Czech Republic
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Petar H Lambrev
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany the Chinese Academy of Sciences, Beijing, 100093, China
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, 1-1, Naka 3-chome, Tsushima, Okayama, 700-8530, Japan
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary.
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, CZ-710 00, Ostrava, Czech Republic.
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Erdei AI, Borbély A, Magyar A, Taricska N, Perczel A, Zsíros O, Garab G, Szűcs E, Ötvös F, Zádor F, Balogh M, Al-Khrasani M, Benyhe S. Biochemical and pharmacological characterization of three opioid-nociceptin hybrid peptide ligands reveals substantially differing modes of their actions. Peptides 2018; 99:205-216. [PMID: 29038035 DOI: 10.1016/j.peptides.2017.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 10/10/2017] [Accepted: 10/11/2017] [Indexed: 12/23/2022]
Abstract
In an attempt to design opioid-nociceptin hybrid peptides, three novel bivalent ligands, H-YGGFGGGRYYRIK-NH2, H-YGGFRYYRIK-NH2 and Ac-RYYRIKGGGYGGFL-OH were synthesized and studied by biochemical, pharmacological, biophysical and molecular modelling tools. These chimeric molecules consist of YGGF sequence, a crucial motif in the N-terminus of natural opioid peptides, and Ac-RYYRIK-NH2, which was isolated from a combinatorial peptide library as an antagonist or partial agonist that inhibits the biological activity of the endogenously occurring heptadecapeptide nociceptin. Solution structures for the peptides were studied by analysing their circular dichroism spectra. Receptor binding affinities were measured by equilibrium competition experiments using four highly selective radioligands. G-protein activating properties of the multitarget peptides were estimated in [35S]GTPγS binding tests. The three compounds were also measured in electrically stimulated mouse vas deferens (MVD) bioassay. H-YGGFGGGRYYRIK-NH2 (BA55), carrying N-terminal opioid and C-terminal nociceptin-like sequences interconnected with GGG tripeptide spacer displayed a tendency of having either unordered or β-sheet structures, was moderately potent in MVD and possessed a NOP/KOP receptor preference. A similar peptide without spacer H-YGGFRYYRIK-NH2 (BA62) exhibited the weakest effect in MVD, more α-helical periodicity was present in its structure and it exhibited the most efficacious agonist actions in the G-protein stimulation assays. The third hybrid peptide Ac-RYYRIKGGGYGGFL-OH (BA61) unexpectedly displayed opioid receptor affinities, because the opioid message motif is hidden within the C-terminus. The designed chimeric peptide ligands presented in this study accommodate well into a group of multitarget opioid compounds that include opioid-non-opioid peptide dimer analogues, dual non-peptide dimers and mixed peptide- non-peptide bifunctional ligands.
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Affiliation(s)
- Anna I Erdei
- Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, H-6726, Szeged, Temesvári krt. 62., Hungary
| | - Adina Borbély
- MTA-ELTE Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, H-1117, Budapest, Pázmány Péter sétány 1/A, Hungary
| | - Anna Magyar
- MTA-ELTE Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, H-1117, Budapest, Pázmány Péter sétány 1/A, Hungary
| | - Nóra Taricska
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, Eötvös Loránd University, Pázmány P. sétány 1/A, Budapest, H-1117, Hungary
| | - András Perczel
- Laboratory of Structural Chemistry and Biology, Institute of Chemistry, Eötvös Loránd University, Pázmány P. sétány 1/A, Budapest, H-1117, Hungary; MTA-ELTE Protein Modelling Research Group, Institute of Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, H-1117, Budapest, Pázmány Péter sétány 1/A, Hungary
| | - Ottó Zsíros
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, H-6726, Szeged, Temesvári krt. 62., Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, H-6726, Szeged, Temesvári krt. 62., Hungary
| | - Edina Szűcs
- Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, H-6726, Szeged, Temesvári krt. 62., Hungary
| | - Ferenc Ötvös
- Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, H-6726, Szeged, Temesvári krt. 62., Hungary
| | - Ferenc Zádor
- Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, H-6726, Szeged, Temesvári krt. 62., Hungary
| | - Mihály Balogh
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1445, Budapest, Nagyvárad tér 4., Hungary
| | - Mahmoud Al-Khrasani
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1445, Budapest, Nagyvárad tér 4., Hungary
| | - Sándor Benyhe
- Institute of Biochemistry, Biological Research Center, Hungarian Academy of Sciences, H-6726, Szeged, Temesvári krt. 62., Hungary.
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Bar Eyal L, Ranjbar Choubeh R, Cohen E, Eisenberg I, Tamburu C, Dorogi M, Ünnep R, Appavou MS, Nevo R, Raviv U, Reich Z, Garab G, van Amerongen H, Paltiel Y, Keren N. Changes in aggregation states of light-harvesting complexes as a mechanism for modulating energy transfer in desert crust cyanobacteria. Proc Natl Acad Sci U S A 2017; 114:9481-9486. [PMID: 28808031 PMCID: PMC5584450 DOI: 10.1073/pnas.1708206114] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In this paper we propose an energy dissipation mechanism that is completely reliant on changes in the aggregation state of the phycobilisome light-harvesting antenna components. All photosynthetic organisms regulate the efficiency of excitation energy transfer (EET) to fit light energy supply to biochemical demands. Not many do this to the extent required of desert crust cyanobacteria. Following predawn dew deposition, they harvest light energy with maximum efficiency until desiccating in the early morning hours. In the desiccated state, absorbed energy is completely quenched. Time and spectrally resolved fluorescence emission measurements of the desiccated desert crust Leptolyngbya ohadii strain identified (i) reduced EET between phycobilisome components, (ii) shorter fluorescence lifetimes, and (iii) red shift in the emission spectra, compared with the hydrated state. These changes coincide with a loss of the ordered phycobilisome structure, evident from small-angle neutron and X-ray scattering and cryo-transmission electron microscopy data. Based on these observations we propose a model where in the hydrated state the organized rod structure of the phycobilisome supports directional EET to reaction centers with minimal losses due to thermal dissipation. In the desiccated state this structure is lost, giving way to more random aggregates. The resulting EET path will exhibit increased coupling to the environment and enhanced quenching.
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Affiliation(s)
- Leeat Bar Eyal
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Reza Ranjbar Choubeh
- Laboratory of Biophysics, Wageningen University, 6700 ET Wageningen, The Netherlands
| | - Eyal Cohen
- Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ido Eisenberg
- Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Carmen Tamburu
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Márta Dorogi
- Biological Research Centre, Hungarian Academy of Sciences, Szeged 6726, Hungary
| | - Renata Ünnep
- Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1525 Budapest 114, Hungary
| | - Marie-Sousai Appavou
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, 85748 Garching, Germany
| | - Reinat Nevo
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600, Israel
| | - Uri Raviv
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ziv Reich
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600, Israel
| | - Győző Garab
- Biological Research Centre, Hungarian Academy of Sciences, Szeged 6726, Hungary
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, 6700 ET Wageningen, The Netherlands
| | - Yossi Paltiel
- Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Nir Keren
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel;
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31
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Ünnep R, Zsiros O, Hörcsik Z, Markó M, Jajoo A, Kohlbrecher J, Garab G, Nagy G. Low-pH induced reversible reorganizations of chloroplast thylakoid membranes - As revealed by small-angle neutron scattering. Biochim Biophys Acta Bioenerg 2017; 1858:360-365. [PMID: 28237493 DOI: 10.1016/j.bbabio.2017.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 12/20/2022]
Abstract
Energization of thylakoid membranes brings about the acidification of the lumenal aqueous phase, which activates important regulatory mechanisms. Earlier Jajoo and coworkers (2014 FEBS Lett. 588:970) have shown that low pH in isolated plant thylakoid membranes induces changes in the excitation energy distribution between the two photosystems. In order to elucidate the structural background of these changes, we used small-angle neutron scattering on thylakoid membranes exposed to low p2H (pD) and show that gradually lowering the p2H from 8.0 to 5.0 causes small but well discernible reversible diminishment of the periodic order and the lamellar repeat distance and an increased mosaicity - similar to the effects elicited by light-induced acidification of the lumen. Our data strongly suggest that thylakoids dynamically respond to the membrane energization and actively participate in different regulatory mechanisms.
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Affiliation(s)
- Renáta Ünnep
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, H-1121 Budapest, Hungary; Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, 5232 Villigen PSI, Switzerland
| | - Ottó Zsiros
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, H-6701 Szeged, Hungary
| | - Zsolt Hörcsik
- College of Nyíregyháza, Institute of Environmental Science, H-4400 Nyíregyháza, Hungary
| | - Márton Markó
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, H-1121 Budapest, Hungary
| | - Anjana Jajoo
- School of Life Science, Devi Ahilya University, Khandwa Road, Indore 452 001, India
| | - Joachim Kohlbrecher
- Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, 5232 Villigen PSI, Switzerland
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, POB 521, H-6701 Szeged, Hungary; Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, CZ-710 0 Ostrava - Slezská Ostrava, Czech Republic.
| | - Gergely Nagy
- Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, 5232 Villigen PSI, Switzerland; Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, H-1121 Budapest, Hungary.
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32
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Szabó T, Csekő R, Hajdu K, Nagy K, Sipos O, Galajda P, Garab G, Nagy L. Sensing photosynthetic herbicides in an electrochemical flow cell. Photosynth Res 2017; 132:127-134. [PMID: 27709414 DOI: 10.1007/s11120-016-0314-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 09/26/2016] [Indexed: 06/06/2023]
Abstract
Specific inhibitory reactions of herbicides with photosynthetic reaction centers bound to working electrodes were monitored in a conventional electrochemical cell and a newly designed microfluidic electrochemical flow cell. In both cases, the bacterial reaction centers were bound to a transparent conductive metal oxide, indium-tin-oxide, electrode through carbon nanotubes. In the conventional cell, photocurrent densities of up to a few μA/cm2 could be measured routinely. The photocurrent could be blocked by the photosynthetic inhibitor terbutryn (I 50 = 0.38 ± 0.14 μM) and o-phenanthroline (I 50 = 63.9 ± 12.2 μM). The microfluidic flow cell device enabled us to reduce the sample volume and to simplify the electrode arrangement. The useful area of the electrodes remained the same (ca. 2 cm2), similar to the classical electrochemical cell; however, the size of the cell was reduced considerably. The microfluidic flow control enabled us monitoring in real time the binding/unbinding of the inhibitor and cofactor molecules at the secondary quinone site.
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Affiliation(s)
- Tibor Szabó
- Department of Medical Physics and Informatics, University of Szeged, H-6720, Rerrich B. tér 1, Szeged, Hungary
| | - Richárd Csekő
- Department of Medical Physics and Informatics, University of Szeged, H-6720, Rerrich B. tér 1, Szeged, Hungary
| | - Kata Hajdu
- Department of Medical Physics and Informatics, University of Szeged, H-6720, Rerrich B. tér 1, Szeged, Hungary
| | - Krisztina Nagy
- Biological Research Centre, Institue of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary
| | - Orsolya Sipos
- Biological Research Centre, Institue of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary
| | - Péter Galajda
- Biological Research Centre, Institue of Biophysics, Hungarian Academy of Sciences, Szeged, Hungary
| | - Győző Garab
- Biological Research Centre, Institue of Plant Biology, Hungarian Academy of Sciences, Szeged, Hungary
- Biofotonika R&D Ltd., Szeged, Hungary
| | - László Nagy
- Department of Medical Physics and Informatics, University of Szeged, H-6720, Rerrich B. tér 1, Szeged, Hungary.
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Akhtar P, Zhang C, Do TN, Garab G, Lambrev PH, Tan HS. Two-Dimensional Spectroscopy of Chlorophyll a Excited-State Equilibration in Light-Harvesting Complex II. J Phys Chem Lett 2017; 8:257-263. [PMID: 27982601 DOI: 10.1021/acs.jpclett.6b02615] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Excited-state relaxation dynamics and energy-transfer processes in the chlorophyll a (Chl a) manifold of the light-harvesting complex II (LHCII) were examined at physiological temperature using femtosecond two-dimensional electronic spectroscopy (2DES). The experiments were done under conditions free from singlet-singlet annihilation and anisotropic decay. Energy transfer between the different domains of the Chl a manifold was found to proceed on time scales from hundreds of femtoseconds to five picoseconds, before reaching equilibration. No component slower than 10 ps was observed in the spectral equilibration dynamics. We clearly observe the bidirectional (uphill and downhill) energy transfer of the equilibration process between excited states. This bidirectional energy flow, although implicit in the modeling and simulation of the EET processes, has not been observed in any prior transient absorption studies. Furthermore, we identified the spectral forms associated with the different energy transfer lifetimes in the equilibration process.
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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
- Biological Research Centre, Hungarian Academy of Sciences , Temesvári körút 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
| | - Thanh Nhut Do
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
| | - Győző Garab
- Biological Research Centre, Hungarian Academy of Sciences , Temesvári körút 62, Szeged 6726, Hungary
| | - Petar H Lambrev
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
- Biological Research Centre, Hungarian Academy of Sciences , Temesvári körút 62, Szeged 6726, Hungary
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
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Nagy V, Vidal-Meireles A, Tengölics R, Rákhely G, Garab G, Kovács L, Tóth SZ. Ascorbate accumulation during sulphur deprivation and its effects on photosystem II activity and H2 production of the green alga Chlamydomonas reinhardtii. Plant Cell Environ 2016; 39:1460-72. [PMID: 26714836 DOI: 10.1111/pce.12701] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 11/25/2015] [Accepted: 12/18/2015] [Indexed: 05/10/2023]
Abstract
In nature, H2 production in Chlamydomonas reinhardtii serves as a safety valve during the induction of photosynthesis in anoxia, and it prevents the over-reduction of the photosynthetic electron transport chain. Sulphur deprivation of C. reinhardtii also triggers a complex metabolic response resulting in the induction of various stress-related genes, down-regulation of photosynthesis, the establishment of anaerobiosis and expression of active hydrogenase. Photosystem II (PSII) plays dual role in H2 production because it supplies electrons but the evolved O2 inhibits the hydrogenase. Here, we show that upon sulphur deprivation, the ascorbate content in C. reinhardtii increases about 50-fold, reaching the mM range; at this concentration, ascorbate inactivates the Mn-cluster of PSII, and afterwards, it can donate electrons to tyrozin Z(+) at a slow rate. This stage is followed by donor-side-induced photoinhibition, leading to the loss of charge separation activity in PSII and reaction centre degradation. The time point at which maximum ascorbate concentration is reached in the cell is critical for the establishment of anaerobiosis and initiation of H2 production. We also show that ascorbate influenced H2 evolution via altering the photosynthetic electron transport rather than hydrogenase activity and starch degradation.
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Affiliation(s)
- Valéria Nagy
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári krt. 62, H-6726, Szeged, Hungary
| | - André Vidal-Meireles
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári krt. 62, H-6726, Szeged, Hungary
| | - Roland Tengölics
- Department of Biotechnology, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári krt. 62, H-6726, Szeged, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári krt. 62, H-6726, Szeged, Hungary
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári krt. 62, H-6726, Szeged, Hungary
| | - Szilvia Z Tóth
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Temesvári krt. 62, H-6726, Szeged, Hungary
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Herdean A, Teardo E, Nilsson AK, Pfeil BE, Johansson ON, Ünnep R, Nagy G, Zsiros O, Dana S, Solymosi K, Garab G, Szabó I, Spetea C, Lundin B. A voltage-dependent chloride channel fine-tunes photosynthesis in plants. Nat Commun 2016; 7:11654. [PMID: 27216227 PMCID: PMC4890181 DOI: 10.1038/ncomms11654] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/16/2016] [Indexed: 11/17/2022] Open
Abstract
In natural habitats, plants frequently experience rapid changes in the intensity of sunlight. To cope with these changes and maximize growth, plants adjust photosynthetic light utilization in electron transport and photoprotective mechanisms. This involves a proton motive force (PMF) across the thylakoid membrane, postulated to be affected by unknown anion (Cl(-)) channels. Here we report that a bestrophin-like protein from Arabidopsis thaliana functions as a voltage-dependent Cl(-) channel in electrophysiological experiments. AtVCCN1 localizes to the thylakoid membrane, and fine-tunes PMF by anion influx into the lumen during illumination, adjusting electron transport and the photoprotective mechanisms. The activity of AtVCCN1 accelerates the activation of photoprotective mechanisms on sudden shifts to high light. Our results reveal that AtVCCN1, a member of a conserved anion channel family, acts as an early component in the rapid adjustment of photosynthesis in variable light environments.
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Affiliation(s)
- Andrei Herdean
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
| | - Enrico Teardo
- Department of Biology, University of Padova, Padova 35121, Italy
| | - Anders K. Nilsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
| | - Bernard E. Pfeil
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
| | - Oskar N. Johansson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
| | - Renáta Ünnep
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen 5232, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest 1121, Hungary
| | - Gergely Nagy
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen 5232, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Budapest 1121, Hungary
| | - Ottó Zsiros
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged 6701, Hungary
| | - Somnath Dana
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
| | - Katalin Solymosi
- Department of Plant Anatomy, Eötvös Loránd University, Budapest 1117, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged 6701, Hungary
| | - Ildikó Szabó
- Department of Biology, University of Padova, Padova 35121, Italy
- CNR Neuroscience Institute, Padova 35121, Italy
| | - Cornelia Spetea
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
| | - Björn Lundin
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
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Savić A, Mitrović A, Donaldson L, Simonović Radosavljević J, Bogdanović Pristov J, Steinbach G, Garab G, Radotić K. Fluorescence-Detected Linear Dichroism of Wood Cell Walls in Juvenile Serbian Spruce: Estimation of Compression Wood Severity. Microsc Microanal 2016; 22:361-367. [PMID: 26858105 DOI: 10.1017/s143192761600009x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Fluorescence-detected linear dichroism (FDLD) microscopy provides observation of structural order in a microscopic sample and its expression in numerical terms, enabling both quantitative and qualitative comparison among different samples. We applied FDLD microscopy to compare the distribution and alignment of cellulose fibrils in cell walls of compression wood (CW) and normal wood (NW) on stem cross-sections of juvenile Picea omorika trees. Our data indicate a decrease in cellulose fibril order in CW compared with NW. Radial and tangential walls differ considerably in both NW and CW. In radial walls, cellulose fibril order shows a gradual decrease from NW to severe CW, in line with the increase in CW severity. This indicates that FDLD analysis of cellulose fibril order in radial cell walls is a valuable method for estimation of CW severity.
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Affiliation(s)
- Aleksandar Savić
- 1Institute for Multidisciplinary Research,University of Belgrade,Kneza Višeslava 1,11000 Belgrade,Serbia
| | - Aleksandra Mitrović
- 1Institute for Multidisciplinary Research,University of Belgrade,Kneza Višeslava 1,11000 Belgrade,Serbia
| | | | | | - Jelena Bogdanović Pristov
- 1Institute for Multidisciplinary Research,University of Belgrade,Kneza Višeslava 1,11000 Belgrade,Serbia
| | - Gabor Steinbach
- 4Institute of Plant Biology,Biological Research Center,H-6701 Szeged,Hungary
| | - Győző Garab
- 4Institute of Plant Biology,Biological Research Center,H-6701 Szeged,Hungary
| | - Ksenija Radotić
- 1Institute for Multidisciplinary Research,University of Belgrade,Kneza Višeslava 1,11000 Belgrade,Serbia
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37
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Akhtar P, Lingvay M, Kiss T, Deák R, Bóta A, Ughy B, Garab G, Lambrev PH. Excitation energy transfer between Light-harvesting complex II and Photosystem I in reconstituted membranes. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2016; 1857:462-72. [DOI: 10.1016/j.bbabio.2016.01.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/22/2016] [Accepted: 01/27/2016] [Indexed: 12/01/2022]
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Enriquez MM, Akhtar P, Zhang C, Garab G, Lambrev PH, Tan HS. Energy transfer dynamics in trimers and aggregates of light-harvesting complex II probed by 2D electronic spectroscopy. J Chem Phys 2016; 142:212432. [PMID: 26049452 DOI: 10.1063/1.4919239] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The pathways and dynamics of excitation energy transfer between the chlorophyll (Chl) domains in solubilized trimeric and aggregated light-harvesting complex II (LHCII) are examined using two-dimensional electronic spectroscopy (2DES). The LHCII trimers and aggregates exhibit the unquenched and quenched excitonic states of Chl a, respectively. 2DES allows direct correlation of excitation and emission energies of coupled states over population time delays, hence enabling mapping of the energy flow between Chls. By the excitation of the entire Chl b Qy band, energy transfer from Chl b to Chl a states is monitored in the LHCII trimers and aggregates. Global analysis of the two-dimensional (2D) spectra reveals that energy transfer from Chl b to Chl a occurs on fast and slow time scales of 240-270 fs and 2.8 ps for both forms of LHCII. 2D decay-associated spectra resulting from the global analysis identify the correlation between Chl states involved in the energy transfer and decay at a given lifetime. The contribution of singlet-singlet annihilation on the kinetics of Chl energy transfer and decay is also modelled and discussed. The results show a marked change in the energy transfer kinetics in the time range of a few picoseconds. Owing to slow energy equilibration processes, long-lived intermediate Chl a states are present in solubilized trimers, while in aggregates, the population decay of these excited states is significantly accelerated, suggesting that, overall, the energy transfer within the LHCII complexes is faster in the aggregated state.
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Affiliation(s)
- Miriam M Enriquez
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Parveen Akhtar
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary
| | - Cheng Zhang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary
| | - Petar H Lambrev
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
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Cogdell R, Garab G. Introduction to the 49ers' special issue. Photosynth Res 2016; 127:1-3. [PMID: 26445988 DOI: 10.1007/s11120-015-0194-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Richard Cogdell
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, UK.
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, 6701, Szeged, Hungary.
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Herdean A, Nziengui H, Zsiros O, Solymosi K, Garab G, Lundin B, Spetea C. The Arabidopsis Thylakoid Chloride Channel AtCLCe Functions in Chloride Homeostasis and Regulation of Photosynthetic Electron Transport. Front Plant Sci 2016; 7:115. [PMID: 26904077 PMCID: PMC4746265 DOI: 10.3389/fpls.2016.00115] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/21/2016] [Indexed: 05/20/2023]
Abstract
Chloride ions can be translocated across cell membranes through Cl(-) channels or Cl(-)/H(+) exchangers. The thylakoid-located member of the Cl(-) channel CLC family in Arabidopsis thaliana (AtCLCe) was hypothesized to play a role in photosynthetic regulation based on the initial photosynthetic characterization of clce mutant lines. The reduced nitrate content of Arabidopsis clce mutants suggested a role in regulation of plant nitrate homeostasis. In this study, we aimed to further investigate the role of AtCLCe in the regulation of ion homeostasis and photosynthetic processes in the thylakoid membrane. We report that the size and composition of proton motive force were mildly altered in two independent Arabidopsis clce mutant lines. Most pronounced effects in the clce mutants were observed on the photosynthetic electron transport of dark-adapted plants, based on the altered shape and associated parameters of the polyphasic OJIP kinetics of chlorophyll a fluorescence induction. Other alterations were found in the kinetics of state transition and in the macro-organization of photosystem II supercomplexes, as indicated by circular dichroism measurements. Pre-treatment with KCl but not with KNO3 restored the wild-type photosynthetic phenotype. Analyses by transmission electron microscopy revealed a bow-like arrangement of the thylakoid network and a large thylakoid-free stromal region in chloroplast sections from the dark-adapted clce plants. Based on these data, we propose that AtCLCe functions in Cl(-) homeostasis after transition from light to dark, which affects chloroplast ultrastructure and regulation of photosynthetic electron transport.
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Affiliation(s)
- Andrei Herdean
- Department of Biological and Environmental Sciences, University of GothenburgGothenburg, Sweden
| | - Hugues Nziengui
- Department of Biological and Environmental Sciences, University of GothenburgGothenburg, Sweden
| | - Ottó Zsiros
- Biological Research Center, Hungarian Academy of SciencesSzeged, Hungary
| | - Katalin Solymosi
- Department of Plant Anatomy, Eötvös Loránd UniversityBudapest, Hungary
| | - Győző Garab
- Biological Research Center, Hungarian Academy of SciencesSzeged, Hungary
| | - Björn Lundin
- Department of Biological and Environmental Sciences, University of GothenburgGothenburg, Sweden
| | - Cornelia Spetea
- Department of Biological and Environmental Sciences, University of GothenburgGothenburg, Sweden
- *Correspondence: Cornelia Spetea
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Abstract
In this chapter we focus our attention on the enigmatic structural and functional roles of the major, non-bilayer lipid monogalactosyl-diacylglycerol (MGDG) in the thylakoid membrane. We give an overview on the state of the art on the role of MGDG and non-bilayer lipid phases in the xanthophyll cycles in different organisms. We also discuss data on the roles of MGDG and other lipid molecules found in crystal structures of different photosynthetic protein complexes and in lipid-protein assemblies, as well as in the self-assembly of the multilamellar membrane system. Comparison and critical evaluation of different membrane models--that take into account and capitalize on the special properties of non-bilayer lipids and/or non-bilayer lipid phases, and thus to smaller or larger extents deviate from the 'standard' Singer-Nicolson model--will conclude this review. With this chapter the authors hope to further stimulate the discussion about, what we think, is perhaps the most exciting question of membrane biophysics: the why and wherefore of non-bilayer lipids and lipid phases in, or in association with, bilayer biological membranes.
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Affiliation(s)
- Győző Garab
- Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary.
| | - Bettina Ughy
- Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
| | - Reimund Goss
- Institute of Biology, Department of Plant Physiology, University of Leipzig, Leipzig, Germany
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Garab G. Self-assembly and structural-functional flexibility of oxygenic photosynthetic machineries: personal perspectives. Photosynth Res 2016; 127:131-50. [PMID: 26494196 DOI: 10.1007/s11120-015-0192-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/02/2015] [Indexed: 05/24/2023]
Abstract
This short review, with a bit of historical aspect and a strong personal bias and emphases on open questions, is focusing on the (macro-)organization and structural-functional flexibilities of the photosynthetic apparatus of oxygenic photosynthetic organisms at different levels of the structural complexity-selected problems that have attracted most my attention in the past years and decades. These include (i) the anisotropic organization of the pigment-protein complexes and photosynthetic membranes-a basic organizing principle of living matter, which can, and probably should be adopted to intelligent materials; (ii) the organization of protein complexes into chiral macrodomains, large self-assembling highly organized but structurally flexible entities with unique spectroscopic fingerprints-structures, where, important, high-level regulatory functions appear to 'reside'; (iii) a novel, dissipation-assisted mechanism of structural changes, based on a thermo-optic effect: ultrafast thermal transients in the close vicinity of dissipation of unused excitation energy, which is capable of inducing elementary structural changes; it makes plants capable of responding to excess excitation with reaction rates proportional to the overexcitation above the light-saturation of photosynthesis; (iv) the 3D ultrastructure of the granum-stroma thylakoid membrane assembly and other multilamellar membrane systems, and their remodelings-associated with regulatory mechanisms; (v) the molecular organization and structural-functional plasticity of the main light-harvesting complex of plants, in relation to their crystal structure and different in vivo and in vitro states; and (vi) the enigmatic role of non-bilayer lipids and lipid phases in the bilayer thylakoid membrane-warranting its high protein content and contributing to its structural flexibility.
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Szabó T, Magyar M, Hajdu K, Dorogi M, Nyerki E, Tóth T, Lingvay M, Garab G, Hernádi K, Nagy L. Structural and Functional Hierarchy in Photosynthetic Energy Conversion-from Molecules to Nanostructures. Nanoscale Res Lett 2015; 10:458. [PMID: 26619890 PMCID: PMC4666181 DOI: 10.1186/s11671-015-1173-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
Basic principles of structural and functional requirements of photosynthetic energy conversion in hierarchically organized machineries are reviewed. Blueprints of photosynthesis, the energetic basis of virtually all life on Earth, can serve the basis for constructing artificial light energy-converting molecular devices. In photosynthetic organisms, the conversion of light energy into chemical energy takes places in highly organized fine-tunable systems with structural and functional hierarchy. The incident photons are absorbed by light-harvesting complexes, which funnel the excitation energy into reaction centre (RC) protein complexes containing redox-active chlorophyll molecules; the primary charge separations in the RCs are followed by vectorial transport of charges (electrons and protons) in the photosynthetic membrane. RCs possess properties that make their use in solar energy-converting and integrated optoelectronic systems feasible. Therefore, there is a large interest in many laboratories and in the industry toward their use in molecular devices. RCs have been bound to different carrier matrices, with their photophysical and photochemical activities largely retained in the nano-systems and with electronic connection to conducting surfaces. We show examples of RCs bound to carbon-based materials (functionalized and non-functionalized single- and multiwalled carbon nanotubes), transitional metal oxides (ITO) and conducting polymers and porous silicon and characterize their photochemical activities. Recently, we adapted several physical and chemical methods for binding RCs to different nanomaterials. It is generally found that the P(+)(QAQB)(-) charge pair, which is formed after single saturating light excitation is stabilized after the attachment of the RCs to the nanostructures, which is followed by slow reorganization of the protein structure. Measuring the electric conductivity in a direct contact mode or in electrochemical cell indicates that there is an electronic interaction between the protein and the inorganic carrier matrices. This can be a basis of sensing element of bio-hybrid device for biosensor and/or optoelectronic applications.
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Affiliation(s)
- Tibor Szabó
- Department of Medical Physics and Informatics, University of Szeged, Rerrich B. tér 1., H-6721, Szeged, Hungary.
| | - Melinda Magyar
- Department of Medical Physics and Informatics, University of Szeged, Rerrich B. tér 1., H-6721, Szeged, Hungary.
| | - Kata Hajdu
- Department of Medical Physics and Informatics, University of Szeged, Rerrich B. tér 1., H-6721, Szeged, Hungary.
| | - Márta Dorogi
- Biological Research Center, Hungarian Academy of Sciences, Temesvari krt.62, H-6726, Szeged, Hungary.
- Biophotonics R&D Ltd., Temesvari krt.62, H-6726, Szeged, Hungary.
| | - Emil Nyerki
- Department of Medical Physics and Informatics, University of Szeged, Rerrich B. tér 1., H-6721, Szeged, Hungary.
| | - Tünde Tóth
- Department of Medical Physics and Informatics, University of Szeged, Rerrich B. tér 1., H-6721, Szeged, Hungary.
| | - Mónika Lingvay
- Department of Medical Physics and Informatics, University of Szeged, Rerrich B. tér 1., H-6721, Szeged, Hungary.
| | - Győző Garab
- Biological Research Center, Hungarian Academy of Sciences, Temesvari krt.62, H-6726, Szeged, Hungary.
- Biophotonics R&D Ltd., Temesvari krt.62, H-6726, Szeged, Hungary.
| | - Klára Hernádi
- Department of Applied and Environmental Chemistry, University of Szeged, Szeged, Hungary.
| | - László Nagy
- Department of Medical Physics and Informatics, University of Szeged, Rerrich B. tér 1., H-6721, Szeged, Hungary.
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Tóth TN, Chukhutsina V, Domonkos I, Knoppová J, Komenda J, Kis M, Lénárt Z, Garab G, Kovács L, Gombos Z, van Amerongen H. Carotenoids are essential for the assembly of cyanobacterial photosynthetic complexes. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2015; 1847:1153-65. [DOI: 10.1016/j.bbabio.2015.05.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 05/26/2015] [Accepted: 05/29/2015] [Indexed: 01/15/2023]
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Karlsson PM, Herdean A, Adolfsson L, Beebo A, Nziengui H, Irigoyen S, Ünnep R, Zsiros O, Nagy G, Garab G, Aronsson H, Versaw WK, Spetea C. The Arabidopsis thylakoid transporter PHT4;1 influences phosphate availability for ATP synthesis and plant growth. Plant J 2015; 84:99-110. [PMID: 26255788 DOI: 10.1111/tpj.12962] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 07/14/2015] [Accepted: 08/03/2015] [Indexed: 05/24/2023]
Abstract
The Arabidopsis phosphate transporter PHT4;1 was previously localized to the chloroplast thylakoid membrane. Here we investigated the physiological consequences of the absence of PHT4;1 for photosynthesis and plant growth. In standard growth conditions, two independent Arabidopsis knockout mutant lines displayed significantly reduced leaf size and biomass but normal phosphorus content. When mutants were grown in high-phosphate conditions, the leaf phosphorus levels increased and the growth phenotype was suppressed. Photosynthetic measurements indicated that in the absence of PHT4;1 stromal phosphate was reduced to levels that limited ATP synthase activity. This resulted in reduced CO2 fixation and accumulation of soluble sugars, limiting plant growth. The mutants also displayed faster induction of non-photochemical quenching than the wild type, in line with the increased contribution of ΔpH to the proton-motive force across thylakoids. Small-angle neutron scattering showed a smaller lamellar repeat distance, whereas circular dichroism spectroscopy indicated a perturbed long-range order of photosystem II (PSII) complexes in the mutant thylakoids. The absence of PHT4;1 did not alter the PSII repair cycle, as indicated by wild-type levels of phosphorylation of PSII proteins, inactivation and D1 protein degradation. Interestingly, the expression of genes for several thylakoid proteins was downregulated in the mutants, but the relative levels of the corresponding proteins were either not affected or could not be discerned. Based on these data, we propose that PHT4;1 plays an important role in chloroplast phosphate compartmentation and ATP synthesis, which affect plant growth. It also maintains the ionic environment of thylakoids, which affects the macro-organization of complexes and induction of photoprotective mechanisms.
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Affiliation(s)
- Patrik M Karlsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Gothenburg, 405 30, Sweden
| | - Andrei Herdean
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Gothenburg, 405 30, Sweden
| | - Lisa Adolfsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Gothenburg, 405 30, Sweden
| | - Azeez Beebo
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Gothenburg, 405 30, Sweden
| | - Hugues Nziengui
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Gothenburg, 405 30, Sweden
| | - Sonia Irigoyen
- Department of Biology, Texas A&M University, 3258, TAMU College Station, TX, 77843, USA
| | - Renáta Ünnep
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, 5232, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Box 49, Budapest, H-1525, Hungary
| | - Ottó Zsiros
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Box 521, Szeged, H-6701, Hungary
| | - Gergely Nagy
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, 5232, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Box 49, Budapest, H-1525, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Box 521, Szeged, H-6701, Hungary
| | - Henrik Aronsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Gothenburg, 405 30, Sweden
| | - Wayne K Versaw
- Department of Biology, Texas A&M University, 3258, TAMU College Station, TX, 77843, USA
| | - Cornelia Spetea
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Gothenburg, 405 30, Sweden
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Akhtar P, Dorogi M, Pawlak K, Kovács L, Bóta A, Kiss T, Garab G, Lambrev PH. Pigment interactions in light-harvesting complex II in different molecular environments. J Biol Chem 2015; 290:4877-4886. [PMID: 25525277 PMCID: PMC4335227 DOI: 10.1074/jbc.m114.607770] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/16/2014] [Indexed: 11/06/2022] Open
Abstract
Extraction of plant light-harvesting complex II (LHCII) from the native thylakoid membrane or from aggregates by the use of surfactants brings about significant changes in the excitonic circular dichroism (CD) spectrum and fluorescence quantum yield. To elucidate the cause of these changes, e.g. trimer-trimer contacts or surfactant-induced structural perturbations, we compared the CD spectra and fluorescence kinetics of LHCII aggregates, artificial and native LHCII-lipid membranes, and LHCII solubilized in different detergents or trapped in polymer gel. By this means we were able to identify CD spectral changes specific to LHCII-LHCII interactions, at (-)-437 and (+)-484 nm, and changes specific to the interaction with the detergent n-dodecyl-β-maltoside (β-DM) or membrane lipids, at (+)-447 and (-)-494 nm. The latter change is attributed to the conformational change of the LHCII-bound carotenoid neoxanthin, by analyzing the CD spectra of neoxanthin-deficient plant thylakoid membranes. The neoxanthin-specific band at (-)-494 nm was not pronounced in LHCII in detergent-free gels or solubilized in the α isomer of DM but was present when LHCII was reconstituted in membranes composed of phosphatidylcholine or plant thylakoid lipids, indicating that the conformation of neoxanthin is sensitive to the molecular environment. Neither the aggregation-specific CD bands, nor the surfactant-specific bands were positively associated with the onset of fluorescence quenching, which could be triggered without invoking such spectral changes. Significant quenching was not active in reconstituted LHCII proteoliposomes, whereas a high degree of energetic connectivity, depending on the lipid:protein ratio, in these membranes allows for efficient light harvesting.
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Affiliation(s)
- Parveen Akhtar
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - Márta Dorogi
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - Krzysztof Pawlak
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - László Kovács
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - Attila Bóta
- Hungarian Academy of Sciences, Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Magyar tudósok körútja 2, 1117 Budapest, Hungary
| | - Teréz Kiss
- Hungarian Academy of Sciences, Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Magyar tudósok körútja 2, 1117 Budapest, Hungary
| | - Győző Garab
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - Petar H Lambrev
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and.
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Nellaepalli S, Zsiros O, Tóth T, Yadavalli V, Garab G, Subramanyam R, Kovács L. Heat- and light-induced detachment of the light harvesting complex from isolated photosystem I supercomplexes. J Photochem Photobiol B 2014; 137:13-20. [PMID: 24874922 DOI: 10.1016/j.jphotobiol.2014.04.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 04/23/2014] [Accepted: 04/25/2014] [Indexed: 11/26/2022]
Abstract
In a previous study, using photosystem I enriched stroma thylakoid membrane vesicles, we have shown that the light harvesting complexes of this photosystem are prone to heat- and light-induced, thermo-optically driven detachment from the supercomplex [43]. We have also shown that the splitting of the supercomplex occurs in a gradual and specific manner, selectively affecting the different constituents of the antenna complexes. Here we further analyse these heat- and light-induced processes in isolated Photosystem I supercomplex using circular dichroism and 77K fluorescence emission spectroscopy and immuno blotting, and obtain further details on the sequence of events of the dissociation process as well as on the thermal stability of the different components. Our absorption and circular dichroism spectroscopy and immuno blotting data show that the dissociation of LHCI from PSI-LHCI supercomplex starts above 50°C. Also, the low temperature fluorescence emission spectra depicts decrease of maximum fluorescence emission at 730nm and an increase of the intensity at 685nm, and about 10nm blue-shifts, from 730 to 720nm and from 685 to 676nm, respectively, indicating the heat (50°C) induced detachment of LHCI from PSI core complexes. The reaction centre proteins are highly stable even at high temperatures. Lhca2 is more heat stable than the other light harvesting protein complexes of PSI, whereas Lhca4 and Lhca3 are rather labile. Combined heat and light treatments significantly enhances the disorganization of PSI-LHCI supercomplexes, indicating a thermo-optic mechanism, which might have significant role under combined heat and light stress conditions.
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Affiliation(s)
- Sreedhar Nellaepalli
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Ottó Zsiros
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Hungary
| | - Tünde Tóth
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Hungary
| | - Venkateswarlu Yadavalli
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Hungary
| | - Rajagopal Subramanyam
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India; Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - László Kovács
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Hungary.
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Unnep R, Nagy G, Markó M, Garab G. Monitoring thylakoid ultrastructural changes in vivo using small-angle neutron scattering. Plant Physiol Biochem 2014; 81:197-207. [PMID: 24629664 DOI: 10.1016/j.plaphy.2014.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 02/08/2014] [Indexed: 05/01/2023]
Abstract
The light reactions of oxygenic photosynthesis take place in the thylakoid membranes, flattened vesicles, which contain the two photosystems and also embed the cytochrome b6f complex and the ATP synthase. In general, the thylakoid membranes are assembled into multilamellar membrane systems, which warrant an optimal light capturing efficiency. In nature, they show astounding variations, primarily due to large variations in their protein composition, which is controlled by multilevel regulatory mechanisms during long-term acclimation and short-term adaptation processes and also influenced by biotic or abiotic stresses - indicating a substantial degree of flexibility in the membrane ultrastructure. The better understanding of the dynamic features of this membrane system requires the use of non-invasive techniques, such as small angle neutron scattering (SANS), which is capable of providing accurate, statistically and spatially averaged information on the repeat distances of periodically organized thylakoid membranes under physiologically relevant conditions with time resolutions of seconds and minutes. In this review, after a short section on the basic properties of neutrons, we outline the fundamental principles of SANS measurements, its strengths and weaknesses in comparison to complementary structure investigation techniques. Then we overview recent results on isolated plant thylakoid membranes, and on living cyanobacterial and algal cells as well as on whole leaves. Special attention is paid to light-induced reversible ultrastructural changes in vivo, which, in cyanobacterial and diatom cells, were uncovered with the aid of SANS measurements; we also discuss the role of membrane reorganizations in light adaptation and photoprotection mechanisms.
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Affiliation(s)
- Renáta Unnep
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary
| | - Gergely Nagy
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary; Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Márton Markó
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary; Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, POB 521, H-6701 Szeged, Hungary.
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Hind G, Wall JS, Várkonyi Z, Istokovics A, Lambrev PH, Garab G. Membrane crystals of plant light-harvesting complex II disassemble reversibly in light. Plant Cell Physiol 2014; 55:1296-303. [PMID: 24793749 PMCID: PMC4184361 DOI: 10.1093/pcp/pcu064] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 04/28/2014] [Indexed: 05/08/2023]
Abstract
Using the mass-measuring capability of scanning transmission electron microscopy, we demonstrate that membrane crystals of the main light-harvesting complex of plants possess the ability to undergo light-induced dark-reversible disassociations, independently of the photochemical apparatus. This is the first direct visualization of light-driven reversible reorganizations in an isolated photosynthetic antenna. These reorganizations, identified earlier by circular dichroism (CD), can be accounted for by a biological thermo-optic transition: structural changes are induced by fast heat transients and thermal instabilities near the dissipation, and self-association of the complexes in the lipid matrix. A comparable process in native membranes is indicated by earlier findings of essentially identical kinetics, and intensity and temperature dependences of the ΔCD in granal thylakoids.
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Affiliation(s)
- Geoffrey Hind
- Biosciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Joseph S Wall
- Biosciences Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Zsuzsanna Várkonyi
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, PO Box 521, H-6701, Hungary
| | - Anita Istokovics
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, PO Box 521, H-6701, Hungary
| | - Petar H Lambrev
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, PO Box 521, H-6701, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, PO Box 521, H-6701, Hungary
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50
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Krumova SB, Várkonyi Z, Lambrev PH, Kovács L, Todinova SJ, Busheva MC, Taneva SG, Garab G. Heat- and light-induced detachment of the light-harvesting antenna complexes of photosystem I in isolated stroma thylakoid membranes. J Photochem Photobiol B 2014; 137:4-12. [PMID: 24912404 DOI: 10.1016/j.jphotobiol.2014.04.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 04/22/2014] [Accepted: 04/25/2014] [Indexed: 11/15/2022]
Abstract
The multisubunit pigment-protein complex of photosystem I (PSI) consists of a core and peripheral light-harvesting antenna (LHCI). PSI is thought to be a rather rigid system and very little is known about its structural and functional flexibility. Recent data, however, suggest LHCI detachment from the PSI supercomplex upon heat and light treatments. Furthermore, it was suggested that the splitting off of LHCI acts as a safety valve for PSI core upon photoinhibition (Alboresi et al., 2009). In this work we analyzed the heat- and light-induced reorganizations in isolated PSI vesicles (stroma membrane vesicles enriched in PSI). Using differential scanning calorimetry we revealed a stepwise disassembly of PSI supercomplex above 50°C. Circular dichroism, sucrose gradient centrifugation and 77K fluorescence experiments identified the sequence of events of PSI destabilization: 3min heating at 60°C or 40min white light illumination at 25°C resulted in pronounced Lhca1/4 detachment from the PSI supercomplex, which is then followed by the degradation of Lhca2/3. The similarity of the main structural effects due to heat and light treatments supports the notion that thermo-optic mechanism, structural changes induced by ultrafast local thermal transients, which has earlier been shown to be responsible for structural changes in the antenna system of photosystem II, can also regulate the assembly and functioning of PSI antenna.
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Affiliation(s)
- S B Krumova
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Zs Várkonyi
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - P H Lambrev
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - L Kovács
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - S J Todinova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - M C Busheva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - S G Taneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - G Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary.
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