1
|
Zheng M, Pang X, Chen M, Tian L. Ultrafast energy quenching mechanism of LHCSR3-dependent photoprotection in Chlamydomonas. Nat Commun 2024; 15:4437. [PMID: 38789432 PMCID: PMC11126702 DOI: 10.1038/s41467-024-48789-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Photosynthetic organisms have evolved an essential energy-dependent quenching (qE) mechanism to avoid any lethal damages caused by high light. While the triggering mechanism of qE has been well addressed, candidates for quenchers are often debated. This lack of understanding is because of the tremendous difficulty in measuring intact cells using transient absorption techniques. Here, we have conducted femtosecond pump-probe measurements to characterize this photophysical reaction using micro-sized cell fractions of the green alga Chlamydomonas reinhardtii that retain physiological qE function. Combined with kinetic modeling, we have demonstrated the presence of an ultrafast excitation energy transfer (EET) pathway from Chlorophyll a (Chl a) Qy to a carotenoid (car) S1 state, therefore proposing that this carotenoid, likely lutein1, is the quencher. This work has provided an easy-to-prepare qE active thylakoid membrane system for advanced spectroscopic studies and demonstrated that the energy dissipation pathway of qE is evolutionarily conserved from green algae to land plants.
Collapse
Affiliation(s)
- Mengyuan Zheng
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- China National Botanical Garden, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaojie Pang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- China National Botanical Garden, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ming Chen
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- China National Botanical Garden, Beijing, 100093, China
| | - Lijin Tian
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
- China National Botanical Garden, Beijing, 100093, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
2
|
Shi T, Fan D, Xu C, Zheng G, Zhong C, Feng F, Chow WS. The Fitting of the OJ Phase of Chlorophyll Fluorescence Induction Based on an Analytical Solution and Its Application in Urban Heat Island Research. PLANTS (BASEL, SWITZERLAND) 2024; 13:452. [PMID: 38337985 PMCID: PMC10857409 DOI: 10.3390/plants13030452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/28/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
Chlorophyll (Chl) fluorescence induction (FI) upon a dark-light transition has been widely analyzed to derive information on initial events of energy conversion and electron transfer in photosystem II (PSII). However, currently, there is no analytical solution to the differential equation of QA reduction kinetics, raising a doubt about the fitting of FI by numerical iteration solution. We derived an analytical solution to fit the OJ phase of FI, thereby yielding estimates of three parameters: the functional absorption cross-section of PSII (σPSII), a probability parameter that describes the connectivity among PSII complexes (p), and the rate coefficient for QA- oxidation (kox). We found that σPSII, p, and kox exhibited dynamic changes during the transition from O to J. We postulated that in high excitation light, some other energy dissipation pathways may vastly outcompete against excitation energy transfer from a closed PSII trap to an open PSII, thereby giving the impression that connectivity seemingly does not exist. We also conducted a case study on the urban heat island effect on the heat stability of PSII using our method and showed that higher-temperature-acclimated leaves had a greater σPSII, lower kox, and a tendency of lower p towards more shade-type characteristics.
Collapse
Affiliation(s)
- Tongxin Shi
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China; (T.S.)
| | - Dayong Fan
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China; (T.S.)
| | - Chengyang Xu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China; (T.S.)
| | - Guoming Zheng
- Yi Zong Qi Technology (Beijing) Co., Ltd., Beijing 100095, China
| | - Chuanfei Zhong
- Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100093, China
| | - Fei Feng
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China; (T.S.)
| | - Wah Soon Chow
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT 2601, Australia
| |
Collapse
|
3
|
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. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5458-5471. [PMID: 37410874 DOI: 10.1093/jxb/erad252] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [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
Collapse
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
| |
Collapse
|
4
|
Bhattacharjee S, Neese F, Pantazis DA. Triplet states in the reaction center of Photosystem II. Chem Sci 2023; 14:9503-9516. [PMID: 37712047 PMCID: PMC10498673 DOI: 10.1039/d3sc02985a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 08/16/2023] [Indexed: 09/16/2023] Open
Abstract
In oxygenic photosynthesis sunlight is harvested and funneled as excitation energy into the reaction center (RC) of Photosystem II (PSII), the site of primary charge separation that initiates the photosynthetic electron transfer chain. The chlorophyll ChlD1 pigment of the RC is the primary electron donor, forming a charge-separated radical pair with the vicinal pheophytin PheoD1 (ChlD1+PheoD1-). To avert charge recombination, the electron is further transferred to plastoquinone QA, whereas the hole relaxes to a central pair of chlorophylls (PD1PD2), subsequently driving water oxidation. Spin-triplet states can form within the RC when forward electron transfer is inhibited or back reactions are favored. This can lead to formation of singlet dioxygen, with potential deleterious effects. Here we investigate the nature and properties of triplet states within the PSII RC using a multiscale quantum-mechanics/molecular-mechanics (QM/MM) approach. The low-energy spectrum of excited singlet and triplet states, of both local and charge-transfer nature, is compared using range-separated time-dependent density functional theory (TD-DFT). We further compute electron paramagnetic resonance properties (zero-field splitting parameters and hyperfine coupling constants) of relaxed triplet states and compare them with available experimental data. Moreover, the electrostatic modulation of excited state energetics and redox properties of RC pigments by the semiquinone QA- is described. The results provide a detailed electronic-level understanding of triplet states within the PSII RC and form a refined basis for discussing primary and secondary electron transfer, charge recombination pathways, and possible photoprotection mechanisms in PSII.
Collapse
Affiliation(s)
- Sinjini Bhattacharjee
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| |
Collapse
|
5
|
Akagi C, Kurihara Y, Makita Y, Kawauchi M, Tsuge T, Aoyama T, Matsui M. Translational activation of ribosome-related genes at initial photoreception is dependent on signals derived from both the nucleus and the chloroplasts in Arabidopsis thaliana. JOURNAL OF PLANT RESEARCH 2023; 136:227-238. [PMID: 36658292 DOI: 10.1007/s10265-022-01430-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Light is one of the indispensable elements that plants need in order to grow and develop. In particular, it is essential for inducing morphogenesis, such as suppression of hypocotyl elongation and cotyledon expansion, that plants undergo when they first emerge after germination. However, there is a lack of knowledge about the gene expression and, in particular, the translational levels that induce a response upon light exposure. We have investigated the translational expression of nuclear genes in Arabidopsis thaliana seedlings germinated in the dark and then exposed to blue monochromatic light. In this study, ribosome profiling analysis was performed in the blue-light-receptor mutant cry1cry2 and the light-signaling mutant hy5 to understand which signaling pathways are responsible for the changes in gene expression at the translational level after blue-light exposure. The analysis showed that the expression of certain chloroplast- and ribosome-related genes was up-regulated at the translational level in the wild type. However, in both mutants the translational up-regulation of ribosome-related genes was apparently compromised. This suggests that light signaling through photoreceptors and the HY5 transcription factor are responsible for translation of ribosome-related genes. To further understand the effect of photoreception by chloroplasts on nuclear gene expression, chloroplast function was inhibited by adding a photosynthesis inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), and a carotenoid synthesis inhibitor, norflurazon. The results show that inhibition of chloroplast function did not lead to an increase in the expression of ribosome-related genes at the translational level. These results suggest that signals from both the nucleus and chloroplasts are required to activate translation of ribosome-related genes during blue-light reception.
Collapse
Affiliation(s)
- Chika Akagi
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Yukio Kurihara
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan
| | - Yuko Makita
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
- Faculty of Engineering, Maebashi Institute of Technology, Kamisadori 460-1, Maebashi, Gunma, 371-0816, Japan
| | - Masaharu Kawauchi
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan
| | - Tomohiko Tsuge
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Takashi Aoyama
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Minami Matsui
- Synthetic Genomics Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
- Graduate School of Nanobioscience Department of Life and Environmental System Science, Yokohama City University, Yokohama, Kanagawa, 236-0027, Japan.
| |
Collapse
|
6
|
Capone M, Sirohiwal A, Aschi M, Pantazis DA, Daidone I. Alternative Fast and Slow Primary Charge-Separation Pathways in Photosystem II. Angew Chem Int Ed Engl 2023; 62:e202216276. [PMID: 36791234 DOI: 10.1002/anie.202216276] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 01/23/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023]
Abstract
Photosystem-II (PSII) is a multi-subunit protein complex that harvests sunlight to perform oxygenic photosynthesis. Initial light-activated charge separation takes place at a reaction centre consisting of four chlorophylls and two pheophytins. Understanding the processes following light excitation remains elusive due to spectral congestion, the ultrafast nature, and multi-component behaviour of the charge-separation process. Here, using advanced computational multiscale approaches which take into account the large-scale configurational flexibility of the system, we identify two possible primary pathways to radical-pair formation that differ by three orders of magnitude in their kinetics. The fast (short-range) pathway is dominant, but the existence of an alternative slow (long-range) charge-separation pathway hints at the evolution of redundancy that may serve other purposes, adaptive or protective, related to formation of the unique oxidative species that drives water oxidation in PSII.
Collapse
Affiliation(s)
- Matteo Capone
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio (Coppito 1), 67010, L'Aquila, Italy
| | - Abhishek Sirohiwal
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany.,Present Address: Department of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University, 10691, Stockholm, Sweden
| | - Massimiliano Aschi
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio (Coppito 1), 67010, L'Aquila, Italy
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Isabella Daidone
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio (Coppito 1), 67010, L'Aquila, Italy
| |
Collapse
|
7
|
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] [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.
Collapse
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
| |
Collapse
|
8
|
Laisk A. Prying into the green black-box. PHOTOSYNTHESIS RESEARCH 2022; 154:89-112. [PMID: 36114436 DOI: 10.1007/s11120-022-00960-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
Life-long efforts of the Tartu photosynthesis research group have been summarized. The measurements were facilitated by self-designed instruments, distinct in multifunctionality and fastresponse time. The black-box type kinetical analysis on intact leaves has revealed several physiologically significant features of leaf photosynthesis. Rubisco studies reflected competition for the active site between the substrates and products, linearizing in vivo kinetics compared with the low-Km in vitro responses. Rubisco Activase usually activates only a small part of the Rubisco, making the rest of it a storage protein. Precisely quantifying absorbed photons and the responding transmittance changes, electron flow rates through cytochrome b6f, plastocyanin and photosystem I were measured, revealing competition between the proton-uncoupled cyclic electron flow from PSI to Cyt b6f to P700+ and the proton-coupled linear flow from PSII to Cyt b6f to P700+. Analyzing responses of O2 evolution and Chl fluorescence to ms-length light pulses we concluded that explanation of the sigmoidal fluorescence induction by excitonic connectivity between PSII units is a misconception. Each PSII processes excitation from its own antenna, but the sigmoidicity is caused by rise of the fluorescence yield of the QA-reduced PSII units after their QB site becomes occupied by reduced plastoquinone (or diuron). Unlike respiration, photosynthetic electrons must prepare their acceptor by coupled synthesis of 3ATP/4e-. Feedback regulation of this ratio leads to oscillations under saturating light and CO2, when the rate is Pi-limited. The slow oscillations (period 60s) indicate that the magnitudes of the deflections in the 3ATP/4e- ratio, corrected by regulating cyclic and alternative electron flow (including the Mehler type O2 reduction), are only a fraction of a per cent. The Pi limitation causes slip in the ATP synthase, slightly increasing the basic 12H+/3ATP requirement.
Collapse
Affiliation(s)
- Agu Laisk
- Institute of Technology, University of Tartu, W. Ostwaldi 1, 51011, Tartu, Estonia.
- Estonian Academy of Sciences, Kohtu 6, 10130, Tallinn, Estonia.
| |
Collapse
|
9
|
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] [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.
Collapse
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
| |
Collapse
|
10
|
Fang Y, Liu D, Jiang J, He A, Zhu R, Tian L. Photoprotective energy quenching in the red alga Porphyridium purpureum occurs at the core antenna of the photosystem II but not at its reaction center. J Biol Chem 2022; 298:101783. [PMID: 35245502 PMCID: PMC8978274 DOI: 10.1016/j.jbc.2022.101783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 01/01/2023] Open
Abstract
Photosynthetic organisms have evolved light-harvesting antennae over time. In cyanobacteria, external phycobilisomes (PBSs) are the dominant antennae, whereas in green algae and higher plants, PBSs have been replaced by proteins of the Lhc family that are integrated in the membrane. Red algae represent an evolutionary intermediate between these two systems, as they employ both PBSs and membrane LHCR proteins as light-harvesting units. Understanding how red algae cope with light is not only interesting for biotechnological applications, but is also of evolutionary interest. For example, energy-dependent quenching (qE) is an essential photoprotective mechanism widely used by species from cyanobacteria to higher plants to avoid light damage; however, the quenching mechanism in red algae remains largely unexplored. Here, we used both pulse amplitude-modulated (PAM) and time-resolved chlorophyll fluorescence to characterize qE kinetics in the red alga Porphyridium purpureum. PAM traces confirmed that qE in P. purpureum is activated by a decrease in the thylakoid lumen pH, whereas time-resolved fluorescence results further revealed the quenching site and ultrafast quenching kinetics. We found that quenching exclusively takes place in the photosystem II (PSII) complexes and preferentially occurs at PSII’s core antenna rather than at its reaction center, with an overall quenching rate of 17.6 ± 3.0 ns−1. In conclusion, we propose that qE in red algae is not a reaction center type of quenching, and that there might be a membrane-bound protein that resembles PsbS of higher plants or LHCSR of green algae that senses low luminal pH and triggers qE in red algae.
Collapse
Affiliation(s)
- Yuan Fang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Dongyang Liu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jingjing Jiang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Axin He
- State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing, China
| | - Rui Zhu
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, China
| | - Lijin Tian
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
11
|
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. THE PLANT CELL 2021; 33:1286-1302. [PMID: 33793891 PMCID: PMC8225241 DOI: 10.1093/plcell/koab008] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [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.
Collapse
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.)
| |
Collapse
|
12
|
Bag P, Chukhutsina V, Zhang Z, Paul S, Ivanov AG, Shutova T, Croce R, Holzwarth AR, Jansson S. Direct energy transfer from photosystem II to photosystem I confers winter sustainability in Scots Pine. Nat Commun 2020; 11:6388. [PMID: 33319777 PMCID: PMC7738668 DOI: 10.1038/s41467-020-20137-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 11/13/2020] [Indexed: 11/24/2022] Open
Abstract
Evergreen conifers in boreal forests can survive extremely cold (freezing) temperatures during long dark winter and fully recover during summer. A phenomenon called “sustained quenching” putatively provides photoprotection and enables their survival, but its precise molecular and physiological mechanisms are not understood. To unveil them, here we have analyzed seasonal adjustment of the photosynthetic machinery of Scots pine (Pinus sylvestris) trees by monitoring multi-year changes in weather, chlorophyll fluorescence, chloroplast ultrastructure, and changes in pigment-protein composition. Analysis of Photosystem II and Photosystem I performance parameters indicate that highly dynamic structural and functional seasonal rearrangements of the photosynthetic apparatus occur. Although several mechanisms might contribute to ‘sustained quenching’ of winter/early spring pine needles, time-resolved fluorescence analysis shows that extreme down-regulation of photosystem II activity along with direct energy transfer from photosystem II to photosystem I play a major role. This mechanism is enabled by extensive thylakoid destacking allowing for the mixing of PSII with PSI complexes. These two linked phenomena play crucial roles in winter acclimation and protection. Evergreen conifers rely on ‘sustained quenching’ to protect their photosynthetic machinery during long, cold winters. Here, Bag et al. show that direct energy transfer (spillover) from photosystem II to photosystem I triggered by loss of grana stacking in chloroplast is the major component of sustained quenching in Scots pine.
Collapse
Affiliation(s)
- Pushan Bag
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Volha Chukhutsina
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Department of Life Sciences, Imperial College London, London, UK
| | - Zishan Zhang
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.,State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Shandong, China
| | - Suman Paul
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.,Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Alexander G Ivanov
- Department of Biology, University of Western Ontario, London, Ontario, Canada.,Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Tatyana Shutova
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Roberta Croce
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Alfred R Holzwarth
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| | - Stefan Jansson
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.
| |
Collapse
|
13
|
Singh S, Mohan Prasad S, Pratap Singh V. Additional calcium and sulfur manages hexavalent chromium toxicity in Solanum lycopersicum L. and Solanum melongena L. seedlings by involving nitric oxide. JOURNAL OF HAZARDOUS MATERIALS 2020; 398:122607. [PMID: 32768852 DOI: 10.1016/j.jhazmat.2020.122607] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 03/24/2020] [Accepted: 03/27/2020] [Indexed: 05/27/2023]
Abstract
In recent years, nutrient management has gained much attention for mitigating metal stress. But, role of nutrients like calcium (Ca) and sulfur (S) in mitigating Cr(VI) toxicity along with their mechanism of action are still limited. Therefore, the present study was performed to explore role of Ca and S in ameliorating Cr(VI) toxicity in 21 days old seedlings of Solanum lycopersicum L. and Solanum melongena L. Chromium (VI) reduced tolerance index and altered root traits due to greater Cr accumulation in the cell wall and cellular organelles due to down-regulation in thiols and phytochelatins that lead to alterations in photosynthesis. However, Ca or S stimulated vacuolar sequestration of Cr(VI) and reduced its uptake at the cell wall. This was coincided with up-regulation in glutathione-S-transferase activity, and amounts of thiols and phytochelatins. Cr(VI) caused oxidative stress together with up-regulation in superoxide dismutase and catalase, and proline metabolism while Ca and S reversed these effects. Chromium (VI) inhibited nitrate reductase activity while Ca and S reversed this response. NG-nitro-l-arginine methyl ester augmented Cr(VI) toxicity but sodium nitroprusside (SNP) mitigated Cr(VI) toxicity. Overall results show that Ca and S both are able in ameliorating Cr(VI) toxicity and require nitric oxide for this task.
Collapse
Affiliation(s)
- Samiksha Singh
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Prayagraj, 211002, India
| | - Sheo Mohan Prasad
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Prayagraj, 211002, India.
| | - Vijay Pratap Singh
- Plant Physiology Laboratory, Department of Botany, C.M.P. Degree College, A Constituent Post Graduate College of University of Allahabad, Prayagraj, 211002, India
| |
Collapse
|
14
|
Oja V, Laisk A. Time- and reduction-dependent rise of photosystem II fluorescence during microseconds-long inductions in leaves. PHOTOSYNTHESIS RESEARCH 2020; 145:209-225. [PMID: 32918663 DOI: 10.1007/s11120-020-00783-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 09/02/2020] [Indexed: 05/16/2023]
Abstract
Lettuce (Lactuca sativa) and benth (Nicotiana benthamiana) leaves were illuminated with 720 nm background light to mix S-states and oxidize electron carriers. Green-filtered xenon flashes of different photon dose were applied and O2 evolution induced by a flash was measured. After light intensity gradient across the leaf was mathematically considered, the flash-induced PSII electron transport (= 4·O2 evolution) exponentially increased with the flash photon dose in any differential layer of the leaf optical density. This proved the absence of excitonic connectivity between PSII units. Time courses of flash light intensity and 680 nm chlorophyll fluorescence emission were recorded. While with connected PSII the sigmoidal fluorescence rise has been explained by quenching of excitation in closed PSII by its open neighbors, in the absence of connectivity the sigmoidicity indicates gradual rise of the fluorescence yield of an individual closed PSII during the induction. Two phases were discerned: the specific fluorescence yield immediately increased from Fo to 1.8Fo in a PSII, whose reaction center became closed; fluorescence yield of the closed PSII was keeping time-dependent rise from 1.8Fo to about 3Fo, approaching the flash fluorescence yield Ff = 0.6Fm during 40 μs. The time-dependent fluorescence rise was resolved from the quenching by 3Car triplets and related to protein conformational change. We suggest that QA reduction induces a conformational change, which by energetic or structural means closes the gate for excitation entrance into the central radical pair trap-efficiently when QB cannot accept the electron, but less efficiently when it can.
Collapse
Affiliation(s)
- Vello Oja
- Institute of Technology, University of Tartu, Nooruse st. 1, 50411, Tartu, Estonia
| | - Agu Laisk
- Institute of Technology, University of Tartu, Nooruse st. 1, 50411, Tartu, Estonia.
| |
Collapse
|
15
|
Mascoli V, Bersanini L, Croce R. Far-red absorption and light-use efficiency trade-offs in chlorophyll f photosynthesis. NATURE PLANTS 2020; 6:1044-1053. [PMID: 32661277 DOI: 10.1038/s41477-020-0718-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/04/2020] [Indexed: 05/28/2023]
Abstract
Plants and cyanobacteria use the chlorophylls embedded in their photosystems to absorb photons and perform charge separation, the first step of converting solar energy to chemical energy. While oxygenic photosynthesis is primarily based on chlorophyll a photochemistry, which is powered by red light, a few cyanobacterial species can harness less energetic photons when growing in far-red light. Acclimatization to far-red light involves the incorporation of a small number of molecules of red-shifted chlorophyll f in the photosystems, whereas the most abundant pigment remains chlorophyll a. Due to its different energetics, chlorophyll f is expected to alter the excited-state dynamics of the photosynthetic units and, ultimately, their performances. Here we combined time-resolved fluorescence measurements on intact cells and isolated complexes to show that chlorophyll f insertion slows down the overall energy trapping in both photosystems. While this marginally affects the efficiency of photosystem I, it substantially decreases that of photosystem II. Nevertheless, we show that despite the lower energy output, the insertion of red-shifted chlorophylls in the photosystems remains advantageous in environments that are enriched in far-red light and therefore represents a viable strategy for extending the photosynthetically active spectrum in other organisms, including plants. However, careful design of the new photosynthetic units will be required to preserve their efficiency.
Collapse
Affiliation(s)
- Vincenzo Mascoli
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Luca Bersanini
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Roberta Croce
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| |
Collapse
|
16
|
Chukhutsina VU, Liu X, Xu P, Croce R. Light-harvesting complex II is an antenna of photosystem I in dark-adapted plants. NATURE PLANTS 2020; 6:860-868. [PMID: 32572215 DOI: 10.1038/s41477-020-0693-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 05/14/2020] [Indexed: 05/19/2023]
Abstract
Photosystem I (PSI) is a major player in the light reactions of photosynthesis. In higher plants, it consists of a core complex and four external antennae, Lhca1-4 forming the PSI-light-harvesting complex I (LHCI) supercomplex. The protein and pigment composition as well as the spectroscopic properties of this complex are considered to be identical in different higher plant species. In addition to the four Lhca, a pool of mobile LHCII increases the antenna size of PSI under most light conditions. In this work, we have first investigated purified PSI complexes and then PSI in vivo upon long-term dark-adaptation of four well-studied plant species: Arabidopsis thaliana, Zea mays, Nicotiana tabacum and Hordeum vulgare. By performing time-resolved fluorescence measurements, we show that LHCII is associated with PSI also in a dark-adapted state in all the plant species investigated. The number of LHCII subunits per PSI is plant-dependent, varying between one and three. Furthermore, we show that the spectroscopic properties of PSI-LHCI supercomplexes differ in different plants.
Collapse
Affiliation(s)
- Volha U Chukhutsina
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, Amsterdam, the Netherlands
| | - Xin Liu
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, Amsterdam, the Netherlands
| | - Pengqi Xu
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, Amsterdam, the Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, Amsterdam, the Netherlands.
| |
Collapse
|
17
|
Ostroumov EE, Götze JP, Reus M, Lambrev PH, Holzwarth AR. Characterization of fluorescent chlorophyll charge-transfer states as intermediates in the excited state quenching of light-harvesting complex II. PHOTOSYNTHESIS RESEARCH 2020; 144:171-193. [PMID: 32307623 DOI: 10.1007/s11120-020-00745-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/31/2020] [Indexed: 05/20/2023]
Abstract
Light-harvesting complex II (LHCII) is the major antenna complex in higher plants and green algae. It has been suggested that a major part of the excited state energy dissipation in the so-called "non-photochemical quenching" (NPQ) is located in this antenna complex. We have performed an ultrafast kinetics study of the low-energy fluorescent states related to quenching in LHCII in both aggregated and the crystalline form. In both sample types the chlorophyll (Chl) excited states of LHCII are strongly quenched in a similar fashion. Quenching is accompanied by the appearance of new far-red (FR) fluorescence bands from energetically low-lying Chl excited states. The kinetics of quenching, its temperature dependence down to 4 K, and the properties of the FR-emitting states are very similar both in LHCII aggregates and in the crystal. No such FR-emitting states are found in unquenched trimeric LHCII. We conclude that these states represent weakly emitting Chl-Chl charge-transfer (CT) states, whose formation is part of the quenching process. Quantum chemical calculations of the lowest energy exciton and CT states, explicitly including the coupling to the specific protein environment, provide detailed insight into the chemical nature of the CT states and the mechanism of CT quenching. The experimental data combined with the results of the calculations strongly suggest that the quenching mechanism consists of a sequence of two proton-coupled electron transfer steps involving the three quenching center Chls 610/611/612. The FR-emitting CT states are reaction intermediates in this sequence. The polarity-controlled internal reprotonation of the E175/K179 aa pair is suggested as the switch controlling quenching. A unified model is proposed that is able to explain all known conditions of quenching or non-quenching of LHCII, depending on the environment without invoking any major conformational changes of the protein.
Collapse
Affiliation(s)
- Evgeny E Ostroumov
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany
- Quantum Matter Institute, University of British Columbia, 2355 East Mall, Vancouver, V6T 1Z1, Canada
| | - Jan P Götze
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany
- Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
| | - Michael Reus
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany
| | - Petar H Lambrev
- Biological Research Centre, Temesvári krt. 62, Szeged, 6726, Hungary
| | - Alfred R Holzwarth
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany.
| |
Collapse
|
18
|
van Amerongen H, Chmeliov J. Instantaneous switching between different modes of non-photochemical quenching in plants. Consequences for increasing biomass production. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148119. [DOI: 10.1016/j.bbabio.2019.148119] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/29/2019] [Accepted: 11/08/2019] [Indexed: 11/25/2022]
|
19
|
Laisk A, Oja V. Variable fluorescence of closed photochemical reaction centers. PHOTOSYNTHESIS RESEARCH 2020; 143:335-346. [PMID: 31960223 DOI: 10.1007/s11120-020-00712-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/13/2020] [Indexed: 05/12/2023]
Abstract
Chlorophyll fluorescence induction during 0.4 to 200 ms multiple-turnover pulses (MTP) was measured in parallel with O2 evolution induced by the MTP light. Additionally, a saturating single-turnover flash (STF) was applied at the end of each MTP and the total MTP +STF O2 evolution was measured. Quantum yield of O2 evolution during the MTP transients was calculated and related to the number of open PSII centers, found from the STF O2 evolution. Proportionality between the number of open PSII and their running photochemical activity showed the quantum yield of open PSII remained constant independent of the closure of adjacent centers. During the induction, total fluorescence was partitioned between Fo of all the open centers and Fc of all the closed centers. The fluorescence yield of a closed center was 0.55 of the final Fm while less than a half of the centers were closed, but later increased, approaching Fm to the end of the induction. In the framework of the antenna/radical pair equilibrium model, the collective rise of the fluorescence of centers closed earlier during the induction is explained by an electric field, facilitating return of excitation energy from the Pheo- P680+ radical pair to the antenna.
Collapse
Affiliation(s)
- Agu Laisk
- Institute of Technology, University of Tartu, Nooruse st. 1, 50411, Tartu, Estonia.
| | - Vello Oja
- Institute of Technology, University of Tartu, Nooruse st. 1, 50411, Tartu, Estonia
| |
Collapse
|
20
|
Application of decay- and evolution-associated spectra for molecular systems with spectral shifts or inherent inhomogeneities. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.110403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
21
|
Chukhutsina VU, Holzwarth AR, Croce R. Time-resolved fluorescence measurements on leaves: principles and recent developments. PHOTOSYNTHESIS RESEARCH 2019; 140:355-369. [PMID: 30478711 PMCID: PMC6509100 DOI: 10.1007/s11120-018-0607-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/15/2018] [Indexed: 05/03/2023]
Abstract
Photosynthesis starts when a pigment in the photosynthetic antennae absorbs a photon. The electronic excitation energy is then transferred through the network of light-harvesting pigments to special chlorophyll (Chl) molecules in the reaction centres, where electron transfer is initiated. Energy transfer and primary electron transfer processes take place on timescales ranging from femtoseconds to nanoseconds, and can be monitored in real time via time-resolved fluorescence spectroscopy. This method is widely used for measurements on unicellular photosynthetic organisms, isolated photosynthetic membranes, and individual complexes. Measurements on intact leaves remain a challenge due to their high structural heterogeneity, high scattering, and high optical density, which can lead to optical artefacts. However, detailed information on the dynamics of these early steps, and the underlying structure-function relationships, is highly informative and urgently required in order to get deeper insights into the physiological regulation mechanisms of primary photosynthesis. Here, we describe a current methodology of time-resolved fluorescence measurements on intact leaves in the picosecond to nanosecond time range. Principles of fluorescence measurements on intact leaves, possible sources of alterations of fluorescence kinetics and the ways to overcome them are addressed. We also describe how our understanding of the organisation and function of photosynthetic proteins and energy flow dynamics in intact leaves can be enriched through the application of time-resolved fluorescence spectroscopy on leaves. For that, an example of a measurement on Zea mays leaves is presented.
Collapse
Affiliation(s)
- Volha U Chukhutsina
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Alfred R Holzwarth
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, 1081 HV, Amsterdam, The Netherlands.
| |
Collapse
|
22
|
Knox PP, Lukashev EP, Gorokhov VV, Seifullina NK, Paschenko VZ. Relaxation processes accompanying electron stabilization in the quinone acceptor part of Rb. sphaeroides reaction centers. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2018; 189:145-151. [PMID: 30347352 DOI: 10.1016/j.jphotobiol.2018.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 06/08/2023]
Abstract
The temperature dependence of the dark recombination rate in photooxidized bacteriochlorophyll (P) and photoreduced quinone acceptors (ubiquinones) QA and QB of photosynthetic reaction centers of purple bacteria Rhodobacter sphaeroides (Rb. sphaeroides) was studied. Photoinduced changes in the absorption were detected in the Qx absorption band of photooxidized bacteriochlorophyll at 600 nm and in the bands corresponding to the redox changes of ubiquinones at 335 and 420-450 nm. Kinetic analysis was used to evaluate the activation energy and the characteristic time of the transient process of relaxation accompanying electron stabilization at the final quinone acceptor. A comparative study of the kinetics of oxidation-reduction reactions of photoactive bacteriochlorophyll RC purple bacteria and quinone acceptors in their individual absorption bands is an informative approach to studying the mechanisms of this stabilization. The analysis of the revealed kinetic differences makes it possible to estimate the activation energy and the characteristic times of the transition relaxation processes associated with the stabilization of the electron in the quinone acceptor part of RC. Purple bacterial reaction centers have fundamental similarities with PSII reaction centers. Such a similarity represents evolutional closeness between the two types of RC. So it is possible that the photoinduced charge separation in PSII RC, as well as in purple bacteria RC, is also accompanied by definite conformational changes. The possible role of hydrogen bonds of surrounding protein in the relaxation processes accompanying the electron transfer to quinone acceptors is discussed.
Collapse
Affiliation(s)
- P P Knox
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia
| | - E P Lukashev
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia
| | - V V Gorokhov
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia
| | - N Kh Seifullina
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia
| | - V Z Paschenko
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia.
| |
Collapse
|
23
|
El-Khouly ME, El-Mohsnawy E, Fukuzumi S. Solar energy conversion: From natural to artificial photosynthesis. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2017. [DOI: 10.1016/j.jphotochemrev.2017.02.001] [Citation(s) in RCA: 182] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
24
|
Snellenburg JJ, Wlodarczyk LM, Dekker JP, van Grondelle R, van Stokkum IH. A model for the 77 K excited state dynamics in Chlamydomonas reinhardtii in state 1 and state 2. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:64-72. [DOI: 10.1016/j.bbabio.2016.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/06/2016] [Accepted: 10/07/2016] [Indexed: 01/28/2023]
|
25
|
Olson TL, Espiritu E, Edwardraja S, Simmons CR, Williams JC, Ghirlanda G, Allen JP. Design of dinuclear manganese cofactors for bacterial reaction centers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:539-547. [PMID: 26392146 DOI: 10.1016/j.bbabio.2015.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 09/14/2015] [Indexed: 12/28/2022]
Abstract
A compelling target for the design of electron transfer proteins with novel cofactors is to create a model for the oxygen-evolving complex, a Mn4Ca cluster, of photosystem II. A mononuclear Mn cofactor can be added to the bacterial reaction center, but the addition of multiple metal centers is constrained by the native protein architecture. Alternatively, metal centers can be incorporated into artificial proteins. Designs for the addition of dinuclear metal centers to four-helix bundles resulted in three artificial proteins with ligands for one, two, or three dinuclear metal centers able to bind Mn. The three-dimensional structure determined by X-ray crystallography of one of the Mn-proteins confirmed the design features and revealed details concerning coordination of the Mn center. Electron transfer between these artificial Mn-proteins and bacterial reaction centers was investigated using optical spectroscopy. After formation of a light-induced, charge-separated state, the experiments showed that the Mn-proteins can donate an electron to the oxidized bacteriochlorophyll dimer of modified reaction centers, with the Mn-proteins having additional metal centers being more effective at this electron transfer reaction. Modeling of the structure of the Mn-protein docked to the reaction center showed that the artificial protein likely binds on the periplasmic surface similarly to cytochrome c2, the natural secondary donor. Combining reaction centers with exogenous artificial proteins provides the opportunity to create ligands and investigate the influence of inhomogeneous protein environments on multinuclear redox-active metal centers. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.
Collapse
Affiliation(s)
- Tien L Olson
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA
| | - Eduardo Espiritu
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA
| | | | - Chad R Simmons
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA
| | - JoAnn C Williams
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA
| | - Giovanna Ghirlanda
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA
| | - James P Allen
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA.
| |
Collapse
|
26
|
Chukhutsina V, Bersanini L, Aro EM, van Amerongen H. Cyanobacterial flv4-2 Operon-Encoded Proteins Optimize Light Harvesting and Charge Separation in Photosystem II. MOLECULAR PLANT 2015; 8:747-61. [PMID: 25704162 DOI: 10.1016/j.molp.2014.12.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 12/09/2014] [Accepted: 12/21/2014] [Indexed: 05/11/2023]
Abstract
Photosystem II (PSII) complexes drive the water-splitting reaction necessary to transform sunlight into chemical energy. However, too much light can damage and disrupt PSII. In cyanobacteria, the flv4-2 operon encodes three proteins (Flv2, Flv4, and Sll0218), which safeguard PSII activity under air-level CO2 and in high light conditions. However, the exact mechanism of action of these proteins has not been clarified yet. We demonstrate that the PSII electron transfer properties are influenced by the flv4-2 operon-encoded proteins. Accelerated secondary charge separation kinetics was observed upon expression/overexpression of the flv4-2 operon. This is likely induced by docking of the Flv2/Flv4 heterodimer in the vicinity of the QB pocket of PSII, which, in turn, increases the QB redox potential and consequently stabilizes forward electron transfer. The alternative electron transfer route constituted by Flv2/Flv4 sequesters electrons from QB(-) guaranteeing the dissipation of excess excitation energy in PSII under stressful conditions. In addition, we demonstrate that in the absence of the flv4-2 operon-encoded proteins, about 20% of the phycobilisome antenna becomes detached from the reaction centers, thus decreasing light harvesting. Phycobilisome detachment is a consequence of a decreased relative content of PSII dimers, a feature observed in the absence of the Sll0218 protein.
Collapse
Affiliation(s)
- Volha Chukhutsina
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, The Netherlands; MicroSpectroscopy Centre, Wageningen University, 6703HA Wageningen, The Netherlands; BioSolarCells, P.O. Box 98, 6700AB Wageningen, The Netherlands
| | - Luca Bersanini
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Eva-Mari Aro
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, The Netherlands; MicroSpectroscopy Centre, Wageningen University, 6703HA Wageningen, The Netherlands; BioSolarCells, P.O. Box 98, 6700AB Wageningen, The Netherlands.
| |
Collapse
|
27
|
Gibasiewicz K, Adamiec M, Luciński R, Giera W, Chełminiak P, Szewczyk S, Sipińska W, Głów E, Karolczak J, van Grondelle R, Jackowski G. Monte Carlo simulations of excitation and electron transfer in grana membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:314-327. [DOI: 10.1016/j.bbabio.2014.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 12/05/2014] [Accepted: 12/09/2014] [Indexed: 11/30/2022]
|
28
|
Caffarri S, Tibiletti T, Jennings RC, Santabarbara S. A comparison between plant photosystem I and photosystem II architecture and functioning. Curr Protein Pept Sci 2015; 15:296-331. [PMID: 24678674 PMCID: PMC4030627 DOI: 10.2174/1389203715666140327102218] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 11/22/2013] [Accepted: 03/16/2014] [Indexed: 01/31/2023]
Abstract
Oxygenic photosynthesis is indispensable both for the development and maintenance of life on earth by converting
light energy into chemical energy and by producing molecular oxygen and consuming carbon dioxide. This latter
process has been responsible for reducing the CO2 from its very high levels in the primitive atmosphere to the present low
levels and thus reducing global temperatures to levels conducive to the development of life. Photosystem I and photosystem
II are the two multi-protein complexes that contain the pigments necessary to harvest photons and use light energy to
catalyse the primary photosynthetic endergonic reactions producing high energy compounds. Both photosystems are
highly organised membrane supercomplexes composed of a core complex, containing the reaction centre where electron
transport is initiated, and of a peripheral antenna system, which is important for light harvesting and photosynthetic activity
regulation. If on the one hand both the chemical reactions catalysed by the two photosystems and their detailed structure
are different, on the other hand they share many similarities. In this review we discuss and compare various aspects of
the organisation, functioning and regulation of plant photosystems by comparing them for similarities and differences as
obtained by structural, biochemical and spectroscopic investigations.
Collapse
Affiliation(s)
| | | | | | - Stefano Santabarbara
- Laboratoire de Génétique et de Biophysique des Plantes (LGBP), Aix-Marseille Université, Faculté des Sciences de Luminy, 163 Avenue de Luminy, 13009, Marseille, France.
| |
Collapse
|
29
|
Schansker G, Tóth SZ, Holzwarth AR, Garab G. Chlorophyll a fluorescence: beyond the limits of the Q(A) model. PHOTOSYNTHESIS RESEARCH 2014; 120:43-58. [PMID: 23456268 DOI: 10.1007/s11120-013-9806-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 02/18/2013] [Indexed: 05/03/2023]
Abstract
Chlorophyll a fluorescence is a non-invasive tool widely used in photosynthesis research. According to the dominant interpretation, based on the model proposed by Duysens and Sweers (1963, Special Issue of Plant and Cell Physiology, pp 353-372), the fluorescence changes reflect primarily changes in the redox state of Q(A), the primary quinone electron acceptor of photosystem II (PSII). While it is clearly successful in monitoring the photochemical activity of PSII, a number of important observations cannot be explained within the framework of this simple model. Alternative interpretations have been proposed but were not supported satisfactorily by experimental data. In this review we concentrate on the processes determining the fluorescence rise on a dark-to-light transition and critically analyze the experimental data and the existing models. Recent experiments have provided additional evidence for the involvement of a second process influencing the fluorescence rise once Q(A) is reduced. These observations are best explained by a light-induced conformational change, the focal point of our review. We also want to emphasize that-based on the presently available experimental findings-conclusions on α/ß-centers, PSII connectivity, and the assignment of FV/FM to the maximum PSII quantum yield may require critical re-evaluations. At the same time, it has to be emphasized that for a deeper understanding of the underlying physical mechanism(s) systematic studies on light-induced changes in the structure and reaction kinetics of the PSII reaction center are required.
Collapse
Affiliation(s)
- Gert Schansker
- Institute of Plant Biology, Biological Research Center Szeged, Hungarian Academy of Sciences, Szeged, 6701, Hungary,
| | | | | | | |
Collapse
|
30
|
Rizzo F, Zucchelli G, Jennings R, Santabarbara S. Wavelength dependence of the fluorescence emission under conditions of open and closed Photosystem II reaction centres in the green alga Chlorella sorokiniana. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:726-33. [PMID: 24561096 DOI: 10.1016/j.bbabio.2014.02.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/10/2014] [Accepted: 02/12/2014] [Indexed: 11/29/2022]
Abstract
The fluorescence emission characteristics of the photosynthetic apparatus under conditions of open (F0) and closed (FM) Photosystem II reaction centres have been investigated under steady state conditions and by monitoring the decay lifetimes of the excited state, in vivo, in the green alga Chlorella sorokiniana. The results indicate a marked wavelength dependence of the ratio of the variable fluorescence, FV=FM-F0, over FM, a parameter that is often employed to estimate the maximal quantum efficiency of Photosystem II. The maximal value of the FV/FM ratio is observed between 660 and 680nm and the minimal in the 690-730nm region. It is possible to attribute the spectral variation of FV/FM principally to the contribution of Photosystem I fluorescence emission at room temperature. Moreover, the analysis of the excited state lifetime at F0 and FM indicates only a small wavelength dependence of Photosystem II trapping efficiency in vivo.
Collapse
Affiliation(s)
- Federico Rizzo
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via Celoria 26, 20133 Milano, Italy; Dipartimento di Bioscienze, Università di Milano, via Celoria 26, 20133 Milano, Italy
| | - Giuseppe Zucchelli
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via Celoria 26, 20133 Milano, Italy; Dipartimento di Bioscienze, Università di Milano, via Celoria 26, 20133 Milano, Italy
| | - Robert Jennings
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via Celoria 26, 20133 Milano, Italy; Dipartimento di Bioscienze, Università di Milano, via Celoria 26, 20133 Milano, Italy
| | - Stefano Santabarbara
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via Celoria 26, 20133 Milano, Italy; Dipartimento di Bioscienze, Università di Milano, via Celoria 26, 20133 Milano, Italy.
| |
Collapse
|
31
|
Non-Photochemical Quenching Mechanisms in Intact Organisms as Derived from Ultrafast-Fluorescence Kinetic Studies. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2014. [DOI: 10.1007/978-94-017-9032-1_5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
32
|
van Oort B, Kargul J, Maghlaoui K, Barber J, van Amerongen H. Fluorescence kinetics of PSII crystals containing Ca(2+) or Sr(2+) in the oxygen evolving complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:264-9. [PMID: 24269510 DOI: 10.1016/j.bbabio.2013.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 11/06/2013] [Accepted: 11/12/2013] [Indexed: 12/11/2022]
Abstract
Photosystem II (PSII) is the pigment-protein complex which converts sunlight energy into chemical energy by catalysing the process of light-driven oxidation of water into reducing equivalents in the form of protons and electrons. Three-dimensional structures from x-ray crystallography have been used extensively to model these processes. However, the crystal structures are not necessarily identical to those of the solubilised complexes. Here we compared picosecond fluorescence of solubilised and crystallised PSII core particles isolated from the thermophilic cyanobacterium Thermosynechococcus elongatus. The fluorescence of the crystals is sensitive to the presence of artificial electron acceptors (K3Fe(CN)3) and electron transport inhibitors (DCMU). In PSII with reaction centres in the open state, the picosecond fluorescence of PSII crystals and solubilised PSII is indistinguishable. Additionally we compared picosecond fluorescence of native PSII with PSII in which Ca(2) in the oxygen evolving complex (OEC) is biosynthetically replaced by Sr(2+). With the Sr(2+) replaced OEC the average fluorescence decay slows down slightly (81ps to 85ps), and reaction centres are less readily closed, indicating that both energy transfer/trapping and electron transfer are affected by the replacement.
Collapse
Affiliation(s)
- Bart van Oort
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
| | - Joanna Kargul
- Department of Plant Molecular Physiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | | | - James Barber
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P. O. Box 8128, 6700 ET Wageningen, The Netherlands
| |
Collapse
|
33
|
Krausz E. Selective and differential optical spectroscopies in photosynthesis. PHOTOSYNTHESIS RESEARCH 2013; 116:411-426. [PMID: 23839302 DOI: 10.1007/s11120-013-9881-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 06/28/2013] [Indexed: 06/02/2023]
Abstract
Photosynthetic pigments are inherently intense optical absorbers and have strong polarisation characteristics. They can also luminesce strongly. These properties have led optical spectroscopies to be, quite naturally, key techniques in photosynthesis. However, there are typically many pigments in a photosynthetic assembly, which when combined with the very significant inhomogeneous and homogeneous linewidths characteristic of optical transitions, leads to spectral congestion. This in turn has made it difficult to provide a definitive and detailed electronic structure for many photosynthetic assemblies. An electronic structure is, however, necessary to provide a foundation for any complete description of fundamental processes in photosynthesis, particularly those in reaction centres. A wide range of selective and differential spectral techniques have been developed to help overcome the problems of spectral complexity and congestion. The techniques can serve to either reduce spectral linewidths and/or extract chromophore specific information from unresolved spectral features. Complementary spectral datasets, generated by a number of techniques, may then be combined in a 'multi-dimensional' theoretical analysis so as to constrain and define effective models of photosynthetic assemblies and their fundamental processes. A key example is the work of Renger and his group (Raszewski, Biophys J 88(2):986-998, 2005) on PS II reaction centre assemblies. This article looks to provide an overview of some of these techniques and indicate where their strengths and weaknesses may lie. It highlights some of our own contributions and indicates areas where progress may be possible.
Collapse
Affiliation(s)
- Elmars Krausz
- Research School of Chemistry, Australian National University, Building 35 Science Road, Canberra, ACT, 0200, Australia,
| |
Collapse
|
34
|
Slavov C, Reus M, Holzwarth AR. Two different mechanisms cooperate in the desiccation-induced excited state quenching in Parmelia lichen. J Phys Chem B 2013; 117:11326-36. [PMID: 23841476 DOI: 10.1021/jp402881f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The highly efficient desiccation-induced quenching in the poikilohydric lichen Parmelia sulcata has been studied by ultrafast fluorescence spectroscopy at room temperature (r.t.) and cryogenic temperatures in order to elucidate the quenching mechanism(s) and kinetic reaction models. Analysis of the r.t. data by kinetic target analysis reveals that two different quenching mechanisms contribute to the protection of photosystem II (PS II). The first mechanism is a direct quenching of the PS II antenna and is related to the characteristic F740 nm fluorescence band. Based on the temperature dependence of its spectra and the kinetics, this mechanism is proposed to reflect the formation of a fluorescent (F740) chlorophyll-chlorophyll charge-transfer state. It is discussed in relation to a similar fluorescence band and quenching mechanism observed in light-induced nonphotochemical quenching in higher plants. The second and more efficient quenching process (providing more than 70% of the total PS II quenching) is shown to involve an efficient spillover (energy transfer) from PS II to PS I which can be prevented by a short glutaraldehyde treatment. Desiccation causes a thylakoid-membrane rearrangement which brings into direct contact the PS II and PS I units. The energy transferred to PS I in the spillover process is then quenched highly efficiently in PS I due to the formation of a long-lived P700(+) state in the dried state in the light. As a consequence, both PS II and PS I are protected very efficiently against photodestruction. This dual quenching mechanism is supported by the low temperature kinetics data.
Collapse
Affiliation(s)
- Chavdar Slavov
- Max Planck Institute for Chemical Energy Conversion , D-45470 Mülheim a.d. Ruhr, Germany
| | | | | |
Collapse
|
35
|
Lambrev PH, Miloslavina Y, Jahns P, Holzwarth AR. On the relationship between non-photochemical quenching and photoprotection of Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:760-9. [PMID: 22342615 DOI: 10.1016/j.bbabio.2012.02.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 01/31/2012] [Accepted: 02/02/2012] [Indexed: 11/17/2022]
Abstract
Non-photochemical quenching (NPQ) of chlorophyll fluorescence is thought to be an indicator of an essential regulation and photoprotection mechanism against high-light stress in photosynthetic organisms. NPQ is typically characterized by modulated pulse fluorometry and it is often assumed implicitly to be a good proxy for the actual physiological photoprotection capacity of the organism. Using the results of previously published ultrafast fluorescence measurements on intact leaves of w.t. and mutants of Arabidopsis (Holzwarth et al. 2009) we have developed exact relationships for the fluorescence quenching and the corresponding Photosystem II acceptor side photoprotection effects under NPQ conditions. The approach based on the exciton-radical pair equilibrium model assumes that photodamage results from triplet states generated in the reaction center. The derived relationships allow one to distinguish and determine the individual and combined quenching as well as photoprotection contributions of each of the multiple NPQ mechanisms. Our analysis shows inter alia that quenching and photoprotection are not linearly related and that antenna detachment, which can be identified with the so-called qE mechanism, contributes largely to the measured fluorescence quenching but does not correspond to the most efficient photoprotective response. Conditions are formulated which allow simultaneously the maximal photosynthetic electron flow as well as maximal acceptor side photoprotection. It is shown that maximal photoprotection can be achieved if NPQ is regulated in such a way that PSII reaction centers are open under given light conditions. The results are of fundamental importance for a proper interpretation of the physiological relevance of fluorescence-based NPQ data.
Collapse
Affiliation(s)
- Petar H Lambrev
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstr. 34-36, 45470 Mülheim a.d. Ruhr, Germany
| | | | | | | |
Collapse
|
36
|
|
37
|
Miloslavina Y, de Bianchi S, Dall'Osto L, Bassi R, Holzwarth AR. Quenching in Arabidopsis thaliana mutants lacking monomeric antenna proteins of photosystem II. J Biol Chem 2011; 286:36830-40. [PMID: 21844190 DOI: 10.1074/jbc.m111.273227] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The minor light-harvesting complexes CP24, CP26, and CP29 have been proposed to play a key role in the zeaxanthin (Zx)-dependent high light-induced regulation (NPQ) of excitation energy in higher plants. To characterize the detailed roles of these minor complexes in NPQ and to determine their specific quenching effects we have studied the ultrafast fluorescence kinetics in knockout (ko) mutants koCP26, koCP29, and the double mutant koCP24/CP26. The data provide detailed insight into the quenching processes and the reorganization of the Photosystem (PS) II supercomplex under quenching conditions. All genotypes showed two NPQ quenching sites. Quenching site Q1 is formed by a light-induced functional detachment of parts of the PSII supercomplex and a pronounced quenching of the detached antenna parts. The antenna remaining bound to the PSII core was also quenched substantially in all genotypes under NPQ conditions (quenching site Q2) as compared with the dark-adapted state. The latter quenching was about equally strong in koCP26 and the koCP24/CP26 mutants as in the WT. Q2 quenching was substantially reduced, however, in koCP29 mutants suggesting a key role for CP29 in the total NPQ. The observed quenching effects in the knockout mutants are complicated by the fact that other minor antenna complexes do compensate in part for the lack of the CP24 and/or CP29 complexes. Their lack also causes some LHCII dissociation already in the dark.
Collapse
Affiliation(s)
- Yuliya Miloslavina
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstraße 34-36, D-45470 Mülheim a.d.Ruhr, Germany
| | | | | | | | | |
Collapse
|
38
|
Yokono M, Murakami A, Akimoto S. Excitation energy transfer between photosystem II and photosystem I in red algae: Larger amounts of phycobilisome enhance spillover. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:847-53. [DOI: 10.1016/j.bbabio.2011.03.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 03/25/2011] [Accepted: 03/29/2011] [Indexed: 10/18/2022]
|
39
|
Lambrev PH, Schmitt FJ, Kussin S, Schoengen M, Várkonyi Z, Eichler HJ, Garab G, Renger G. Functional domain size in aggregates of light-harvesting complex II and thylakoid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:1022-31. [PMID: 21616053 DOI: 10.1016/j.bbabio.2011.05.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 05/03/2011] [Accepted: 05/06/2011] [Indexed: 11/18/2022]
Abstract
The functional domain size for efficient excited singlet state quenching was studied in artificial aggregates of the main light-harvesting complex II (LHCIIb) from spinach and in native thylakoid membranes by picosecond time-resolved fluorescence spectroscopy and quantum yield measurements. The domain size was estimated from the efficiency of added exogenous singlet excitation quenchers-phenyl-p-benzoquinone (PPQ) and dinitrobenzene (DNB). The mean fluorescence lifetimes τ(av) were quantified for a range of quencher concentrations. Applying the Stern-Volmer formalism, apparent quenching rate constants k(q) were determined from the dependencies on quencher concentration of the ratio τ(0)(av)/τ(av), where τ(0)(av) is the average fluorescence lifetime of the sample without addition of an exogenous quencher. The functional domain size was gathered from the ratio k(q)'/k(q), i.e., the apparent quenching rate constants determined in aggregates (or membranes), k(q)', and in detergent-solubilised LHCII trimers, k(q), respectively. In LHCII macroaggregates, the resulting values for the domain size were 15-30 LHCII trimers. In native thylakoid membranes the domain size was equivalent to 12-24 LHCII trimers, corresponding to 500-1000 chlorophylls. Virtually the same results were obtained when membranes were suspended in buffers promoting either membrane stacking or destacking. These domain sizes are orders of magnitude smaller than the number of physically connected pigment-protein complexes. Therefore our results imply that the physical size of an antenna system beyond the numbers of a functional domain size has little or no effect on improving the light-harvesting efficiency.
Collapse
Affiliation(s)
- Petar H Lambrev
- Max-Volmer-Laboratory for Biophysical Chemistry PC 14, Berlin Institute of Technology, Strasse des 17. Juni 135, 10623 Berlin, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Ohad I, Raanan H, Keren N, Tchernov D, Kaplan A. Light-induced changes within photosystem II protects Microcoleus sp. in biological desert sand crusts against excess light. PLoS One 2010; 5:e11000. [PMID: 20544016 PMCID: PMC2882322 DOI: 10.1371/journal.pone.0011000] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 05/16/2010] [Indexed: 12/16/2022] Open
Abstract
The filamentous cyanobacterium Microcoleus vaginatus, a major primary producer in desert biological sand crusts, is exposed to frequent hydration (by early morning dew) followed by desiccation during potentially damaging excess light conditions. Nevertheless, its photosynthetic machinery is hardly affected by high light, unlike “model” organisms whereby light-induced oxidative stress leads to photoinactivation of the oxygen-evolving photosystem II (PSII). Field experiments showed a dramatic decline in the fluorescence yield with rising light intensity in both drying and artificially maintained wet plots. Laboratory experiments showed that, contrary to “model” organisms, photosynthesis persists in Microcoleus sp. even at light intensities 2–3 times higher than required to saturate oxygen evolution. This is despite an extensive loss (85–90%) of variable fluorescence and thermoluminescence, representing radiative PSII charge recombination that promotes the generation of damaging singlet oxygen. Light induced loss of variable fluorescence is not inhibited by the electron transfer inhibitors 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), 2,5-dibromo-3-methyl-6-isopropylbenzoquinone (DBMIB), nor the uncoupler carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP), thus indicating that reduction of plastoquinone or O2, or lumen acidification essential for non-photochemical quenching (NPQ) are not involved. The rate of QA− re-oxidation in the presence of DCMU is enhanced with time and intensity of illumination. The difference in temperatures required for maximal thermoluminescence emissions from S2/QA− (Q band, 22°C) and S2,3/QB− (B band, 25°C) charge recombinations is considerably smaller in Microcoleus as compared to “model” photosynthetic organisms, thus indicating a significant alteration of the S2/QA− redox potential. We propose that enhancement of non-radiative charge recombination with rising light intensity may reduce harmful radiative recombination events thereby lowering 1O2 generation and oxidative photodamage under excess illumination. This effective photo-protective mechanism was apparently lost during the evolution from the ancestor cyanobacteria to the higher plant chloroplast.
Collapse
Affiliation(s)
- Itzhak Ohad
- Department of Biological Chemistry, The Hebrew University of Jerusalem, Jerusalem, Irael
| | - Hagai Raanan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nir Keren
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dan Tchernov
- The Interuniversity Institute for Marine Sciences in Eilat, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail:
| |
Collapse
|
41
|
D1 protein variants in Photosystem II from Thermosynechococcus elongatus studied by low temperature optical spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:11-9. [DOI: 10.1016/j.bbabio.2009.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 07/17/2009] [Accepted: 07/20/2009] [Indexed: 11/24/2022]
|
42
|
Holzwarth AR, Miloslavina Y, Nilkens M, Jahns P. Identification of two quenching sites active in the regulation of photosynthetic light-harvesting studied by time-resolved fluorescence. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.10.085] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
43
|
Miloslavina Y, Grouneva I, Lambrev PH, Lepetit B, Goss R, Wilhelm C, Holzwarth AR. Ultrafast fluorescence study on the location and mechanism of non-photochemical quenching in diatoms. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:1189-97. [DOI: 10.1016/j.bbabio.2009.05.012] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 05/08/2009] [Accepted: 05/19/2009] [Indexed: 10/20/2022]
|
44
|
Szczepaniak M, Sugiura M, Holzwarth AR. The role of TyrD in the electron transfer kinetics in Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:1510-7. [DOI: 10.1016/j.bbabio.2008.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 08/29/2008] [Accepted: 09/01/2008] [Indexed: 10/21/2022]
|