1
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Hu C, Elias E, Nawrocki WJ, Croce R. Drought affects both photosystems in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2023; 240:663-675. [PMID: 37530066 DOI: 10.1111/nph.19171] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 07/14/2023] [Indexed: 08/03/2023]
Abstract
Drought is a major abiotic stress that impairs plant growth and development. Despite this, a comprehensive understanding of drought effects on the photosynthetic apparatus is lacking. In this work, we studied the consequences of 14-d drought treatment on Arabidopsis thaliana. We used biochemical and spectroscopic methods to examine photosynthetic membrane composition and functionality. Drought led to the disassembly of PSII supercomplexes and the degradation of PSII core. The light-harvesting complexes (LHCII) instead remain in the membrane but cannot act as an antenna for active PSII, thus representing a potential source of photodamage. This effect can also be observed during nonphotochemical quenching (NPQ) induction when even short pulses of saturating light can lead to photoinhibition. At a later stage, under severe drought stress, the PSI antenna size is also reduced and the PSI-LHCI supercomplexes disassemble. Surprisingly, although we did not observe changes in the PSI core protein content, the functionality of PSI is severely affected, suggesting the accumulation of nonfunctional PSI complexes. We conclude that drought affects both photosystems, although at a different stage, and that the operative quantum efficiency of PSII (ΦPSII ) is very sensitive to drought and can thus be used as a parameter for early detection of drought stress.
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Affiliation(s)
- Chen Hu
- Biophysics of Photosynthesis, Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Eduard Elias
- Biophysics of Photosynthesis, Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Wojciech J Nawrocki
- Biophysics of Photosynthesis, Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, the Netherlands
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2
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Novoderezhkin VI, Croce R. The location of the low-energy states in Lhca1 favors excitation energy transfer to the core in the plant PSI-LHCI supercomplex. PHOTOSYNTHESIS RESEARCH 2023; 156:59-74. [PMID: 36374368 DOI: 10.1007/s11120-022-00979-8] [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: 06/20/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Lhca1 is one of the four pigment-protein complexes composing the outer antenna of plant Photosystem I-light-havesting I supercomplex (PSI-LHCI). It forms a functional dimer with Lhca4 but, differently from this complex, it does not contain 'red-forms,' i.e., pigments absorbing above 700 nm. Interestingly, the recent PSI-LHCI structures suggest that Lhca1 is the main point of delivering the energy harvested by the antenna to the core. To identify the excitation energy pathways in Lhca1, we developed a structure-based exciton model based on the simultaneous fit of the low-temperature absorption, linear dichroism, and fluorescence spectra of wild-type Lhca1 and two mutants, lacking chlorophylls contributing to the long-wavelength region of the absorption. The model enables us to define the locations of the lowest energy pigments in Lhca1 and estimate pathways and timescales of energy transfer within the complex and to the PSI core. We found that Lhca1 has a particular energy landscape with an unusual (compared to Lhca4, LHCII, and CP29) configuration of the low-energy states. Remarkably, these states are located near the core, facilitating direct energy transfer to it. Moreover, the low-energy states of Lhca1 are also coupled to the red-most state (red forms) of the neighboring Lhca4 antenna, providing a pathway for effective excitation energy transfer from Lhca4 to the core.
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Affiliation(s)
- Vladimir I Novoderezhkin
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Leninskie Gory, 119992, Moscow, Russia.
| | - Roberta Croce
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
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3
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Russo M, Casazza AP, Cerullo G, Santabarbara S, Maiuri M. Ultrafast excited state dynamics in the monomeric and trimeric photosystem I core complex of Spirulina platensis probed by two-dimensional electronic spectroscopy. J Chem Phys 2022; 156:164202. [PMID: 35490013 DOI: 10.1063/5.0078911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Photosystem I (PSI), a naturally occurring supercomplex composed of a core part and a light-harvesting antenna, plays an essential role in the photosynthetic electron transfer chain. Evolutionary adaptation dictates a large variability in the type, number, arrangement, and absorption of the Chlorophylls (Chls) responsible for the early steps of light-harvesting and charge separation. For example, the specific location of long-wavelength Chls (referred to as red forms) in the cyanobacterial core has been intensively investigated, but the assignment of the chromophores involved is still controversial. The most red-shifted Chl a form has been observed in the trimer of the PSI core of the cyanobacterium Spirulina platensis, with an absorption centered at ∼740 nm. Here, we apply two-dimensional electronic spectroscopy to study photoexcitation dynamics in isolated trimers and monomers of the PSI core of S. platensis. By means of global analysis, we resolve and compare direct downhill and uphill excitation energy transfer (EET) processes between the bulk Chls and the red forms, observing significant differences between the monomer (lacking the most far red Chl form at 740 nm) and the trimer, with the ultrafast EET component accelerated by five times, from 500 to 100 fs, in the latter. Our findings highlight the complexity of EET dynamics occurring over a broad range of time constants and their sensitivity to energy distribution and arrangement of the cofactors involved. The comparison of monomeric and trimeric forms, differing both in the antenna dimension and in the extent of red forms, enables us to extract significant information regarding PSI functionality.
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Affiliation(s)
- Mattia Russo
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Anna Paola Casazza
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Via Bassini 15a, 20133 Milano, Italy
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Stefano Santabarbara
- Photosynthesis Research Unit, Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, Consiglio Nazionale delle Ricerche, Via Celoria 26, 20133 Milano, Italy
| | - Margherita Maiuri
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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4
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Russo M, Casazza AP, Cerullo G, Santabarbara S, Maiuri M. Direct Evidence for Excitation Energy Transfer Limitations Imposed by Low-Energy Chlorophylls in Photosystem I-Light Harvesting Complex I of Land Plants. J Phys Chem B 2021; 125:3566-3573. [PMID: 33788560 PMCID: PMC8154617 DOI: 10.1021/acs.jpcb.1c01498] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The overall efficiency
of photosynthetic energy conversion depends
both on photochemical and excitation energy transfer processes from
extended light-harvesting antenna networks. Understanding the trade-offs
between increase in the antenna cross section and bandwidth and photochemical
conversion efficiency is of central importance both from a biological
perspective and for the design of biomimetic artificial photosynthetic
complexes. Here, we employ two-dimensional electronic spectroscopy
to spectrally resolve the excitation energy transfer dynamics and
directly correlate them with the initial site of excitation in photosystem
I–light harvesting complex I (PSI-LHCI) supercomplex of land
plants, which has both a large antenna dimension and a wide optical
bandwidth extending to energies lower than the peak of the reaction
center chlorophylls. Upon preferential excitation of the low-energy
chlorophylls (red forms), the average relaxation time in the bulk
supercomplex increases by a factor of 2–3 with respect to unselective
excitation at higher photon energies. This slowdown is interpreted
in terms of an excitation energy transfer limitation from low-energy
chlorophyll forms in the PSI-LHCI. These results aid in defining the
optimum balance between the extension of the antenna bandwidth to
the near-infrared region, which increases light-harvesting capacity,
and high photoconversion quantum efficiency.
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Affiliation(s)
- Mattia Russo
- Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Anna Paola Casazza
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Via Bassini 15a, 20133 Milano, Italy
| | - Giulio Cerullo
- Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Stefano Santabarbara
- Photosynthesis Research Unit, Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, Consiglio Nazionale delle Ricerche, Via Celoria 26, 20133 Milano, Italy
| | - Margherita Maiuri
- Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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5
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Tros M, Novoderezhkin VI, Croce R, van Grondelle R, Romero E. Complete mapping of energy transfer pathways in the plant light-harvesting complex Lhca4. Phys Chem Chem Phys 2020; 22:25720-25729. [PMID: 33146173 DOI: 10.1039/d0cp03351k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The Lhca4 antenna complex of plant Photosystem I (PSI) is characterized by extremely red-shifted and broadened absorption and emission bands from its low-energy chlorophylls (Chls). The mixing of a charge-transfer (CT) state with the excited state manifold causing these so-called red forms results in highly complicated multi-component excited energy transfer (EET) kinetics within the complex. The two-dimensional electronic spectroscopy experiments presented here reveal that EET towards the CT state occurs on three timescales: fast from the red Chls (within 1 ps), slower (5-7 ps) from the stromal side Chls, and very slow (100-200 ps) from a newly discovered 690 nm luminal trap. The excellent agreement between the experimental data with the previously presented Redfield-Förster exciton model of Lhca4 strongly supports the equilibration scheme of the bulk excitations with the dynamically localized CT on the stromal side. Thus, a complete picture of the energy transfer pathways leading to the population of the CT final trap within the whole Lhca4 complex is presented. In view of the environmental sensitivity of the CT contribution to the Lhca4 energy landscape, we speculate that one role of the CT states is to regulate the EET from the peripheral antenna to the PSI core.
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Affiliation(s)
- Martijn Tros
- Department of Biophysics, Faculty of Sciences, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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6
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Akhtar P, Lambrev PH. On the spectral properties and excitation dynamics of long-wavelength chlorophylls in higher-plant photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2020; 1861:148274. [PMID: 32712151 DOI: 10.1016/j.bbabio.2020.148274] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/13/2020] [Accepted: 07/19/2020] [Indexed: 11/20/2022]
Abstract
In higher-plant Photosystem I (PSI), the majority of "red" chlorophylls (absorbing at longer wavelengths than the reaction centre P700) are located in the peripheral antenna, but contradicting reports are given about red forms in the core complex. Here we attempt to clarify the spectroscopic characteristics and quantify the red forms in the PSI core complex, which have profound implication on understanding the energy transfer and charge separation dynamics. To this end we compare the steady-state absorption and fluorescence spectra and picosecond time-resolved fluorescence kinetics of isolated PSI core complex and PSI-LHCI supercomplex from Pisum sativum recorded at 77 K. Gaussian decomposition of the absorption spectra revealed a broad band at 705 nm in the core complex with an oscillator strength of three chlorophylls. Additional absorption at 703 nm and 711 nm in PSI-LHCI indicated up to five red chlorophylls in the peripheral antenna. Analysis of fluorescence emission spectra resolved states emitting at 705, 715 and 722 nm in the core and additional states around 705-710 nm and 733 nm in PSI-LHCI. The red states compete with P700 in trapping excitations in the bulk antenna, which occurs on a timescale of ~20 ps. The three red forms in the core have distinct decay kinetics, probably in part determined by the rate of quenching by the oxidized P700. These results affirm that the red chlorophylls in the core complex must not be neglected when interpreting kinetic experimental results of PSI.
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Affiliation(s)
- Parveen Akhtar
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
| | - Petar H Lambrev
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary.
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7
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Croce R, van Amerongen H. Light harvesting in oxygenic photosynthesis: Structural biology meets spectroscopy. Science 2020; 369:369/6506/eaay2058. [PMID: 32820091 DOI: 10.1126/science.aay2058] [Citation(s) in RCA: 133] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxygenic photosynthesis is the main process that drives life on earth. It starts with the harvesting of solar photons that, after transformation into electronic excitations, lead to charge separation in the reaction centers of photosystems I and II (PSI and PSII). These photosystems are large, modular pigment-protein complexes that work in series to fuel the formation of carbohydrates, concomitantly producing molecular oxygen. Recent advances in cryo-electron microscopy have enabled the determination of PSI and PSII structures in complex with light-harvesting components called "supercomplexes" from different organisms at near-atomic resolution. Here, we review the structural and spectroscopic aspects of PSI and PSII from plants and algae that directly relate to their light-harvesting properties, with special attention paid to the pathways and efficiency of excitation energy transfer and the regulatory aspects.
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Affiliation(s)
- Roberta Croce
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
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8
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Russo M, Petropoulos V, Molotokaite E, Cerullo G, Casazza AP, Maiuri M, Santabarbara S. Ultrafast excited-state dynamics in land plants Photosystem I core and whole supercomplex under oxidised electron donor conditions. PHOTOSYNTHESIS RESEARCH 2020; 144:221-233. [PMID: 32052255 DOI: 10.1007/s11120-020-00717-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 01/28/2020] [Indexed: 05/28/2023]
Abstract
The kinetics of excited-state energy migration were investigated by femtosecond transient absorption in the isolated Photosystem I-Light-Harvesting Complex I (PSI-LHCI) supercomplex and in the isolated PSI core complex of spinach under conditions in which the terminal electron donor P700 is chemically pre-oxidised. It is shown that, under these conditions, the relaxation of the excited state is characterised by lifetimes of about 0.4 ps, 4.5 ps, 15 ps, 35 ps and 65 ps in PSI-LHCI and 0.15 ps, 0.3 ps, 6 ps and 16 ps in the PSI core complex. Compartmental spectral-kinetic modelling indicates that the most likely mechanism to explain the absence of long-lived (ns) excited states is the photochemical population of a radical pair state, which cannot be further stabilised and decays non-radiatively to the ground state with time constants in the order of 6-8 ps.
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Affiliation(s)
- Mattia Russo
- IFN Consiglio Nazionale delle Ricerche, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - Vasilis Petropoulos
- IFN Consiglio Nazionale delle Ricerche, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - Egle Molotokaite
- Photosynthesis Research Unit, Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, Consiglio Nazionale delle Ricerche, Via Celoria 26, 20133, Milan, Italy
| | - Giulio Cerullo
- IFN Consiglio Nazionale delle Ricerche, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - Anna Paola Casazza
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Via Bassini 15a, 20133, Milan, Italy
| | - Margherita Maiuri
- IFN Consiglio Nazionale delle Ricerche, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
| | - Stefano Santabarbara
- Photosynthesis Research Unit, Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, Consiglio Nazionale delle Ricerche, Via Celoria 26, 20133, Milan, Italy.
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9
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Szewczyk S, Abram M, Białek R, Haniewicz P, Karolczak J, Gapiński J, Kargul J, Gibasiewicz K. On the nature of uncoupled chlorophylls in the extremophilic photosystem I-light harvesting I supercomplex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148136. [PMID: 31825811 DOI: 10.1016/j.bbabio.2019.148136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 11/18/2019] [Accepted: 12/05/2019] [Indexed: 01/07/2023]
Abstract
Photosystem I core-light-harvesting antenna supercomplexes (PSI-LHCI) were isolated from the extremophilic red alga Cyanidioschyzon merolae and studied by three fluorescence techniques in order to characterize chlorophylls (Chls) energetically uncoupled from the PSI reaction center (RC). Such Chls are observed in virtually all optical experiments of any PSI core and PSI-LHCI supercomplex preparations across various species and may influence the operation of PSI-based solar cells and other biohybrid systems. However, the nature of the uncoupled Chls (uChls) has never been explored deeply before. In this work, the amount of uChls was controlled by stirring the solution of C. merolae PSI-LHCI supercomplex samples at elevated temperature (~303 K) and was found to increase from <2% in control samples up to 47% in solutions stirred for 3.5 h. The fluorescence spectrum of uChls was found to be blue-shifted by ~20 nm (to ~680 nm) relative to the fluorescence band from Chls that are well coupled to PSI RC. This effect indicates that mechanical stirring leads to disappearance of some red Chls (emitting at above ~700 nm) that are present in the intact LHCI antenna associated with the PSI core. Comparative diffusion studies of control and stirred samples by fluorescence correlation spectroscopy together with biochemical analysis by SDS-PAGE and BN-PAGE indicate that energetically uncoupled Lhcr subunits are likely to be still physically attached to the PSI core, albeit with altered three-dimensional organization due to the mechanical stress.
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Affiliation(s)
- Sebastian Szewczyk
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Mateusz Abram
- Solar Fuels Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland; Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | - Rafał Białek
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Patrycja Haniewicz
- Solar Fuels Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
| | - Jerzy Karolczak
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Jacek Gapiński
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Joanna Kargul
- Solar Fuels Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland.
| | - Krzysztof Gibasiewicz
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland.
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10
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Bos P, Oosterwijk A, Koehorst R, Bader A, Philippi J, van Amerongen H, Wientjes E. Digitonin-sensitive LHCII enlarges the antenna of Photosystem I in stroma lamellae of Arabidopsis thaliana after far-red and blue-light treatment. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:651-658. [PMID: 31299182 DOI: 10.1016/j.bbabio.2019.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 06/14/2019] [Accepted: 07/07/2019] [Indexed: 11/16/2022]
Abstract
Light drives photosynthesis. In plants it is absorbed by light-harvesting antenna complexes associated with Photosystem I (PSI) and photosystem II (PSII). As PSI and PSII work in series, it is important that the excitation pressure on the two photosystems is balanced. When plants are exposed to illumination that overexcites PSII, a special pool of the major light-harvesting complex LHCII is phosphorylated and moves from PSII to PSI (state 2). If instead PSI is over-excited the LHCII complex is dephosphorylated and moves back to PSII (state 1). Recent findings have suggested that LHCII might also transfer energy to PSI in state 1. In this work we used a combination of biochemistry and (time-resolved) fluorescence spectroscopy to investigate the PSI antenna size in state 1 and state 2 for Arabidopsis thaliana. Our data shows that 0.7 ± 0.1 unphosphorylated LHCII trimers per PSI are present in the stroma lamellae of state-1 plants. Upon transition to state 2 the antenna size of PSI in the stroma membrane increases with phosphorylated LHCIIs to a total of 1.2 ± 0.1 LHCII trimers per PSI. Both phosphorylated and unphosphorylated LHCII function as highly efficient PSI antenna.
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Affiliation(s)
- Peter Bos
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Anniek Oosterwijk
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Rob Koehorst
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Arjen Bader
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - John Philippi
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands.
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11
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Remelli W, Santabarbara S. Excitation and emission wavelength dependence of fluorescence spectra in whole cells of the cyanobacterium Synechocystis sp. PPC6803: Influence on the estimation of Photosystem II maximal quantum efficiency. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:1207-1222. [PMID: 30297025 DOI: 10.1016/j.bbabio.2018.09.366] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 09/13/2018] [Accepted: 09/17/2018] [Indexed: 11/20/2022]
Abstract
The fluorescence emission spectrum of Synechocystis sp. PPC6803 cells, at room temperature, displays: i) significant bandshape variations when collected under open (F0) and closed (FM) Photosystem II reaction centre conditions; ii) a marked dependence on the excitation wavelength both under F0 and FM conditions, due to the enhancement of phycobilisomes (PBS) emission upon their direct excitation. As a consequence: iii) the ratio of the variable and maximal fluorescence (FV/FM), that is a commonly employed indicator of the maximal photochemical quantum efficiency of PSII (Φpc, PSII), displays a significant dependency on both the excitation and the emission (detection) wavelength; iv) the FV/FM excitation/emission wavelength dependency is due, primarily, to the overlap of PSII emission with that of supercomplexes showing negligible changes in quantum yield upon trap closure, i.e. PSI and a PBS fraction which is incapable to transfer the excitation energy efficiently to core complexes. v) The contribution to the cellular emission and the relative absorption-cross section of PSII, PSI and uncoupled PBS are extracted using a spectral decomposition strategy. It is concluded that vi) Φpc, PSII is generally underestimated from the FV/FM measurements in this organism and, the degree of the estimation bias, which can exceed 50%, depends on the measurement conditions. Spectral modelling based on the decomposed emission/cross-section profiles were extended to other processes typically monitored from steady-state fluorescence measurements, in the presence of an actinic illumination, in particular non-photochemical quenching. It is suggested that vii) the quenching extent is generally underestimated in analogy to FV/FM but that viii) the location of quenching sites can be discriminated based on the combined excitation/emission spectral analysis.
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Affiliation(s)
- William Remelli
- Photosynthesis Research Unit, Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, 20133 Milano, Italy
| | - Stefano Santabarbara
- Photosynthesis Research Unit, Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, 20133 Milano, Italy.
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12
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Akhtar P, Zhang C, Liu Z, Tan HS, Lambrev PH. Excitation transfer and trapping kinetics in plant photosystem I probed by two-dimensional electronic spectroscopy. PHOTOSYNTHESIS RESEARCH 2018; 135:239-250. [PMID: 28808836 DOI: 10.1007/s11120-017-0427-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/01/2017] [Indexed: 05/24/2023]
Abstract
Photosystem I is a robust and highly efficient biological solar engine. Its capacity to utilize virtually every absorbed photon's energy in a photochemical reaction generates great interest in the kinetics and mechanisms of excitation energy transfer and charge separation. In this work, we have employed room-temperature coherent two-dimensional electronic spectroscopy and time-resolved fluorescence spectroscopy to follow exciton equilibration and excitation trapping in intact Photosystem I complexes as well as core complexes isolated from Pisum sativum. We performed two-dimensional electronic spectroscopy measurements with low excitation pulse energies to record excited-state kinetics free from singlet-singlet annihilation. Global lifetime analysis resolved energy transfer and trapping lifetimes closely matches the time-correlated single-photon counting data. Exciton energy equilibration in the core antenna occurred on a timescale of 0.5 ps. We further observed spectral equilibration component in the core complex with a 3-4 ps lifetime between the bulk Chl states and a state absorbing at 700 nm. Trapping in the core complex occurred with a 20 ps lifetime, which in the supercomplex split into two lifetimes, 16 ps and 67-75 ps. The experimental data could be modelled with two alternative models resulting in equally good fits-a transfer-to-trap-limited model and a trap-limited model. However, the former model is only possible if the 3-4 ps component is ascribed to equilibration with a "red" core antenna pool absorbing at 700 nm. Conversely, if these low-energy states are identified with the P700 reaction centre, the transfer-to-trap-model is ruled out in favour of a trap-limited model.
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Affiliation(s)
- Parveen Akhtar
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged, 6726, Hungary
| | - Cheng Zhang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Zhengtang Liu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
| | - Petar H Lambrev
- Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, Szeged, 6726, Hungary.
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13
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Santabarbara S, Tibiletti T, Remelli W, Caffarri S. Kinetics and heterogeneity of energy transfer from light harvesting complex II to photosystem I in the supercomplex isolated from Arabidopsis. Phys Chem Chem Phys 2018; 19:9210-9222. [PMID: 28319223 DOI: 10.1039/c7cp00554g] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
State transitions are a phenomenon that maintains the excitation balance between photosystem II (PSII) and photosystem I (PSI-LHCI) by controlling their relative absorption cross-sections. Under light conditions exciting PSII preferentially, a trimeric LHCII antenna moves from PSII to PSI-LHCI to form the PSI-LHCI-LHCII supercomplex. In this work, the excited state dynamics in the PSI-LHCI and PSI-LHCI-LHCII supercomplexes isolated from Arabidopsis have been investigated by picosecond time-resolved fluorescence spectroscopy. The excited state decays were analysed using two approaches based on either (i) a sum of discrete exponentials or (ii) a continuous distribution of lifetimes. The results indicate that the energy transfer from LHCII to the bulk of the PSI antenna occurs with an average macroscopic transfer rate in the 35-65 ns-1 interval. Yet, the most satisfactory description of the data is obtained when considering a heterogeneous population containing two PSI-LHCI-LHCII supercomplexes characterised by a transfer time of ∼15 and ∼60 ns-1, likely due to the differences in the strength and orientation of LHCII harboured to PSI. Both these values are of the same order of magnitude of those estimated for the average energy transfer rates from the low energy spectral forms of LHCI to the bulk of the PSI antenna (15-40 ns-1), but they are slower than the transfer from the bulk antenna of PSI to the reaction centre (>150 ns-1), implying a relatively small kinetics bottleneck for the energy transfer from LHCII. Nevertheless, the kinetic limitation imposed by excited state diffusion has a negligible impact on the photochemical quantum efficiency of the supercomplex, which remains about 98% in the case of PSI-LHCI.
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Affiliation(s)
- Stefano Santabarbara
- Photosynthesis Research Unit, Centro di Studio per la Biologia Cellulare e Molecolare delle Piante, Via Celoria 26, 20133 Milan, Italy.
| | - Tania Tibiletti
- Aix Marseille Univ, CEA, CNRS UMR7265 BVME, Laboratoire de Génétique et Biophysique des Plantes, Marseille 13009, France
| | - William Remelli
- Photosynthesis Research Unit, Centro di Studio per la Biologia Cellulare e Molecolare delle Piante, Via Celoria 26, 20133 Milan, Italy.
| | - Stefano Caffarri
- Aix Marseille Univ, CEA, CNRS UMR7265 BVME, Laboratoire de Génétique et Biophysique des Plantes, Marseille 13009, France
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14
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Molotokaite E, Remelli W, Casazza AP, Zucchelli G, Polli D, Cerullo G, Santabarbara S. Trapping Dynamics in Photosystem I-Light Harvesting Complex I of Higher Plants Is Governed by the Competition Between Excited State Diffusion from Low Energy States and Photochemical Charge Separation. J Phys Chem B 2017; 121:9816-9830. [DOI: 10.1021/acs.jpcb.7b07064] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Egle Molotokaite
- Centro
Studi sulla Biologia Cellulare e Molecolare delle Piante, CNR, Via Celoria 26, 20133 Milan, Italy
| | - William Remelli
- Centro
Studi sulla Biologia Cellulare e Molecolare delle Piante, CNR, Via Celoria 26, 20133 Milan, Italy
| | - Anna Paola Casazza
- Istituto
di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Via Bassini 15a, 20133 Milano, Italy
| | - Giuseppe Zucchelli
- Centro
Studi sulla Biologia Cellulare e Molecolare delle Piante, CNR, Via Celoria 26, 20133 Milan, Italy
| | - Dario Polli
- Istituto di Fotonica e Nanotecnologie del CNR, Dipartimento di Fisica, Politecnico di Milano, P.zza Leonardo
da Vinci 32, 20133 Milano, Italy
- Center
for Nano Science and Technology at Polimi, Istituto Italiano di Tecnologia, Via Giovanni Pascoli, 70/3, 20133 Milano, Italy
| | - Giulio Cerullo
- Istituto di Fotonica e Nanotecnologie del CNR, Dipartimento di Fisica, Politecnico di Milano, P.zza Leonardo
da Vinci 32, 20133 Milano, Italy
| | - Stefano Santabarbara
- Centro
Studi sulla Biologia Cellulare e Molecolare delle Piante, CNR, Via Celoria 26, 20133 Milan, Italy
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15
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Nematov S, Casazza AP, Remelli W, Khuvondikov V, Santabarbara S. Spectral dependence of irreversible light-induced fluorescence quenching: Chlorophyll forms with maximal emission at 700-702 and 705-710nm as spectroscopic markers of conformational changes in the core complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:529-543. [PMID: 28499881 DOI: 10.1016/j.bbabio.2017.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 05/03/2017] [Accepted: 05/07/2017] [Indexed: 11/29/2022]
Abstract
The spectral dependence of the irreversible non-photochemical fluorescence quenching associated with photoinhibition in vitro has been comparatively investigated in thylakoid membranes, PSII enriched particles and PSII core complexes isolated from spinach. The analysis of the fluorescence emission spectra of dark-adapted and quenched samples as a function of the detection temperature in the 280-80K interval, indicates that Chlorophyll spectral forms having maximal emission in the 700-702nm and 705-710nm ranges gain relative intensity in concomitance with the establishment of irreversible light-induced quenching, acting thereby as spectroscopic markers. The relative enhancement of the 700-702nm and 705-710nm forms emission could be due either to an increase of their stoichiometric abundance or to their intrinsically low fluorescence quantum yields. These two factors, that can also coexist, need to be promoted by light-induced alterations in chromophore-protein as well as chromophore-chromophore interactions. The bands centred at about 701 and 706nm are also observed in the PSII core complex, suggesting their, at least partial, localisation in proximity to the reaction centre, and the occurrence of light-induced conformational changes in the core subunits.
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Affiliation(s)
- Sherzod Nematov
- Tashkent State Technical University, University str. 2, 100095 Tashkent, Uzbekistan
| | - Anna Paola Casazza
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, Via Bassini 15a, 20133 Milano, Italy
| | - William Remelli
- Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, CNR, Via Celoria 26, 20133 Milan, Italy
| | | | - Stefano Santabarbara
- Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, CNR, Via Celoria 26, 20133 Milan, Italy.
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16
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Zeaxanthin-dependent nonphotochemical quenching does not occur in photosystem I in the higher plant Arabidopsis thaliana. Proc Natl Acad Sci U S A 2017; 114:4828-4832. [PMID: 28416696 DOI: 10.1073/pnas.1621051114] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nonphotochemical quenching (NPQ) is the process that protects the photosynthetic apparatus of plants and algae from photodamage by dissipating as heat the energy absorbed in excess. Studies on NPQ have almost exclusively focused on photosystem II (PSII), as it was believed that NPQ does not occur in photosystem I (PSI). Recently, Ballottari et al. [Ballottari M, et al. (2014) Proc Natl Acad Sci USA 111:E2431-E2438], analyzing PSI particles isolated from an Arabidopsis thaliana mutant that accumulates zeaxanthin constitutively, have reported that this xanthophyll can efficiently induce chlorophyll fluorescence quenching in PSI. In this work, we have checked the biological relevance of this finding by analyzing WT plants under high-light stress conditions. By performing time-resolved fluorescence measurements on PSI isolated from Arabidopsis thaliana WT in dark-adapted and high-light-stressed (NPQ) states, we find that the fluorescence kinetics of both PSI are nearly identical. To validate this result in vivo, we have measured the kinetics of PSI directly on leaves in unquenched and NPQ states; again, no differences were observed. It is concluded that PSI does not undergo NPQ in biologically relevant conditions in Arabidopsis thaliana The possible role of zeaxanthin in PSI photoprotection is discussed.
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17
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Wientjes E, Philippi J, Borst JW, van Amerongen H. Imaging the Photosystem I/Photosystem II chlorophyll ratio inside the leaf. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:259-265. [DOI: 10.1016/j.bbabio.2017.01.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/10/2017] [Accepted: 01/13/2017] [Indexed: 02/03/2023]
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18
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High photochemical trapping efficiency in Photosystem I from the red clade algae Chromera velia and Phaeodactylum tricornutum. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:56-63. [DOI: 10.1016/j.bbabio.2016.10.002] [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: 11/23/2022]
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19
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Alboresi A, Le Quiniou C, Yadav SKN, Scholz M, Meneghesso A, Gerotto C, Simionato D, Hippler M, Boekema EJ, Croce R, Morosinotto T. Conservation of core complex subunits shaped the structure and function of photosystem I in the secondary endosymbiont alga Nannochloropsis gaditana. THE NEW PHYTOLOGIST 2017; 213:714-726. [PMID: 27620972 PMCID: PMC5216901 DOI: 10.1111/nph.14156] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 07/13/2016] [Indexed: 05/03/2023]
Abstract
Photosystem I (PSI) is a pigment protein complex catalyzing the light-driven electron transport from plastocyanin to ferredoxin in oxygenic photosynthetic organisms. Several PSI subunits are highly conserved in cyanobacteria, algae and plants, whereas others are distributed differentially in the various organisms. Here we characterized the structural and functional properties of PSI purified from the heterokont alga Nannochloropsis gaditana, showing that it is organized as a supercomplex including a core complex and an outer antenna, as in plants and other eukaryotic algae. Differently from all known organisms, the N. gaditana PSI supercomplex contains five peripheral antenna proteins, identified by proteome analysis as type-R light-harvesting complexes (LHCr4-8). Two antenna subunits are bound in a conserved position, as in PSI in plants, whereas three additional antennae are associated with the core on the other side. This peculiar antenna association correlates with the presence of PsaF/J and the absence of PsaH, G and K in the N. gaditana genome and proteome. Excitation energy transfer in the supercomplex is highly efficient, leading to a very high trapping efficiency as observed in all other PSI eukaryotes, showing that although the supramolecular organization of PSI changed during evolution, fundamental functional properties such as trapping efficiency were maintained.
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Affiliation(s)
- Alessandro Alboresi
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
| | - Clotilde Le Quiniou
- Department of Physics and Astronomy and Institute for Lasers, Life and BiophotonicsFaculty of SciencesVU University AmsterdamDe Boelelaan 10811081 HVAmsterdamthe Netherlands
| | - Sathish K. N. Yadav
- Electron Microscopy GroupGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
| | - Martin Scholz
- Institute of Plant Biology and BiotechnologyUniversity of MünsterMünster48143Germany
| | - Andrea Meneghesso
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
| | - Caterina Gerotto
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
| | - Diana Simionato
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
| | - Michael Hippler
- Institute of Plant Biology and BiotechnologyUniversity of MünsterMünster48143Germany
| | - Egbert J. Boekema
- Electron Microscopy GroupGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
| | - Roberta Croce
- Department of Physics and Astronomy and Institute for Lasers, Life and BiophotonicsFaculty of SciencesVU University AmsterdamDe Boelelaan 10811081 HVAmsterdamthe Netherlands
| | - Tomas Morosinotto
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
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20
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Structure and energy transfer pathways of the plant photosystem I-LHCI supercomplex. Curr Opin Struct Biol 2016; 39:46-53. [DOI: 10.1016/j.sbi.2016.04.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 04/15/2016] [Accepted: 04/18/2016] [Indexed: 11/19/2022]
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21
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Akhtar P, Lingvay M, Kiss T, Deák R, Bóta A, Ughy B, Garab G, Lambrev PH. Excitation energy transfer between Light-harvesting complex II and Photosystem I in reconstituted membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:462-72. [DOI: 10.1016/j.bbabio.2016.01.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/22/2016] [Accepted: 01/27/2016] [Indexed: 12/01/2022]
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22
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Novoderezhkin VI, Croce R, Wahadoszamen M, Polukhina I, Romero E, van Grondelle R. Mixing of exciton and charge-transfer states in light-harvesting complex Lhca4. Phys Chem Chem Phys 2016; 18:19368-77. [DOI: 10.1039/c6cp02225a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Structure-based modeling of spectra of the wild-type Lhca4 and NH mutant enables us to build the exciton model of the complex that includes a charge-transfer state mixed with the excited-state manifold.
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Affiliation(s)
| | - Roberta Croce
- Department of Biophysics
- Faculty of Sciences
- VU University Amsterdam
- 1081 HV Amsterdam
- The Netherlands
| | - Md. Wahadoszamen
- Department of Biophysics
- Faculty of Sciences
- VU University Amsterdam
- 1081 HV Amsterdam
- The Netherlands
| | - Iryna Polukhina
- Department of Biophysics
- Faculty of Sciences
- VU University Amsterdam
- 1081 HV Amsterdam
- The Netherlands
| | - Elisabet Romero
- Department of Biophysics
- Faculty of Sciences
- VU University Amsterdam
- 1081 HV Amsterdam
- The Netherlands
| | - Rienk van Grondelle
- Department of Biophysics
- Faculty of Sciences
- VU University Amsterdam
- 1081 HV Amsterdam
- The Netherlands
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23
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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: 133] [Impact Index Per Article: 14.8] [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.
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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.
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24
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Iwai M, Yokono M, Kono M, Noguchi K, Akimoto S, Nakano A. Light-harvesting complex Lhcb9 confers a green alga-type photosystem I supercomplex to the moss Physcomitrella patens. NATURE PLANTS 2015; 1:14008. [PMID: 27246756 DOI: 10.1038/nplants.2014.8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 11/14/2014] [Indexed: 05/10/2023]
Abstract
Light-harvesting complex (LHC) proteins in chloroplast thylakoid membranes not only transfer absorbed light energy to the two photosystems but also regulate the rate of energy transfer to avoid photodamage. Here we demonstrate that Lhcb9, a recently discovered LHC protein in the moss Physcomitrella patens, functions to connect LHC proteins with photosystem I (PSI), resulting in the formation of two different types of PSI supercomplexes in thylakoid membranes. We observed that the Lhcb9-containing PSI supercomplex is disassembled in response to excess light conditions. On the basis of our phylogenetic analysis, it appears that P. patens acquired Lhcb9 by horizontal gene transfer from the earlier green algal lineage, leading to the presence of both green alga-type and vascular plant-type PSI supercomplexes, which would have been crucial for conquering the dynamic environmental interface between aquatic and terrestrial conditions it faced during evolution.
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Affiliation(s)
- Masakazu Iwai
- Live Cell Molecular Imaging Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- PRESTO, Japan Science and Technology Agency (JST), Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Makio Yokono
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Hokkaido 060-0819 Japan
| | - Masaru Kono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ko Noguchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Seiji Akimoto
- Molecular Photoscience Research Center, Kobe University, Kobe 657-8501, Japan
| | - Akihiko Nakano
- Live Cell Molecular Imaging Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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25
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Jennings RC, Zucchelli G. Antenna entropy in plant photosystems does not reduce the free energy for primary charge separation. Biophys Chem 2014; 195:16-21. [PMID: 25190479 DOI: 10.1016/j.bpc.2014.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/12/2014] [Accepted: 08/12/2014] [Indexed: 11/17/2022]
Abstract
We have investigated the concept of the so-called "antenna entropy" of higher plant photosystems. Several interesting points emerge: 1. In the case of a photosystemwhich harbours an excited state, the “antenna entropy” is equivalent to the configurational (mixing) entropy of a thermodynamic canonical ensemble. The energy associated with this parameter has been calculated for a hypothetical isoenergetic photosystem, photosystem I and photosystem II, and comes out in the range of 3.5 - 8% of the photon energy considering 680 nm. 2. The “antenna entropy” seems to be a rather unique thermodynamic phenomenon, in as much as it does not modify the free energy available for primary photochemistry, as has been previously suggested. 3. It is underlined that this configurational (mixing) entropy, unlike heat dispersal in a thermal system, does not involve energy dilution. This points out an important difference between thermal and electronic energy dispersal.
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Affiliation(s)
- Robert C Jennings
- Consiglio Nazionale delle Ricerche, Istituto di Biofisica, sede di Milano, via Giovanni Celoria 26, 20133 Milan, Italy; Dipartimento di Bioscienze, Università degli Studi di Milano, via Giovanni Celoria 26, 20133 Milan, Italy.
| | - Giuseppe Zucchelli
- Consiglio Nazionale delle Ricerche, Istituto di Biofisica, sede di Milano, via Giovanni Celoria 26, 20133 Milan, Italy; Dipartimento di Bioscienze, Università degli Studi di Milano, via Giovanni Celoria 26, 20133 Milan, Italy
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26
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Giera W, Szewczyk S, McConnell MD, Snellenburg J, Redding KE, van Grondelle R, Gibasiewicz K. Excitation dynamics in Photosystem I from Chlamydomonas reinhardtii. Comparative studies of isolated complexes and whole cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1756-68. [PMID: 24973599 DOI: 10.1016/j.bbabio.2014.06.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 06/15/2014] [Accepted: 06/18/2014] [Indexed: 11/17/2022]
Abstract
Identical time-resolved fluorescence measurements with ~3.5-ps resolution were performed for three types of PSI preparations from the green alga, Chlamydomonas reinhardtii: isolated PSI cores, isolated PSI-LHCI complexes and PSI-LHCI complexes in whole living cells. Fluorescence decay in these types of PSI preparations has been previously investigated but never under the same experimental conditions. As a result we present consistent picture of excitation dynamics in algal PSI. Temporal evolution of fluorescence spectra can be generally described by three decay components with similar lifetimes in all samples (6-8ps, 25-30ps, 166-314ps). In the PSI cores, the fluorescence decay is dominated by the two fastest components (~90%), which can be assigned to excitation energy trapping in the reaction center by reversible primary charge separation. Excitation dynamics in the PSI-LHCI preparations is more complex because of the energy transfer between the LHCI antenna system and the core. The average trapping time of excitations created in the well coupled LHCI antenna system is about 12-15ps longer than excitations formed in the PSI core antenna. Excitation dynamics in PSI-LHCI complexes in whole living cells is very similar to that observed in isolated complexes. Our data support the view that chlorophylls responsible for the long-wavelength emission are located mostly in LHCI. We also compared in detail our results with the literature data obtained for plant PSI.
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Affiliation(s)
- Wojciech Giera
- Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland.
| | - Sebastian Szewczyk
- Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
| | - Michael D McConnell
- Department of Chemistry and Biochemistry, Arizona State University, 1711 S. Rural Rd, Box 871604, Tempe, AZ 85287-1604, USA
| | - Joris Snellenburg
- Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Kevin E Redding
- Department of Chemistry and Biochemistry, Arizona State University, 1711 S. Rural Rd, Box 871604, Tempe, AZ 85287-1604, USA
| | - Rienk van Grondelle
- Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Krzysztof Gibasiewicz
- Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
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27
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Jennings RC, Santabarbara S, Belgio E, Zucchelli G. The Carnot efficiency and plant photosystems. Biophysics (Nagoya-shi) 2014. [DOI: 10.1134/s0006350914020080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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28
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Redding KE, Sarrou I, Rappaport F, Santabarbara S, Lin S, Reifschneider KT. Modulation of the fluorescence yield in heliobacterial cells by induction of charge recombination in the photosynthetic reaction center. PHOTOSYNTHESIS RESEARCH 2014; 120:221-235. [PMID: 24318506 DOI: 10.1007/s11120-013-9957-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/25/2013] [Indexed: 06/02/2023]
Abstract
Heliobacteria contain a very simple photosynthetic apparatus, consisting of a homodimeric type I reaction center (RC) without a peripheral antenna system and using the unique pigment bacteriochlorophyll (BChl) g. They are thought to use a light-driven cyclic electron transport pathway to pump protons, and thereby phosphorylate ADP, although some of the details of this cycle are yet to be worked out. We previously reported that the fluorescence emission from the heliobacterial RC in vivo was increased by exposure to actinic light, although this variable fluorescence phenomenon exhibited very different characteristics to that in oxygenic phototrophs (Collins et al. 2010). Here, we describe the underlying mechanism behind the variable fluorescence in heliobacterial cells. We find that the ability to stably photobleach P800, the primary donor of the RC, using brief flashes is inversely correlated to the variable fluorescence. Using pump-probe spectroscopy in the nanosecond timescale, we found that illumination of cells with bright light for a few seconds put them in a state in which a significant fraction of the RCs underwent charge recombination from P800 (+)A0 (-) with a time constant of ~20 ns. The fraction of RCs in the rapidly back-reacting state correlated very well with the variable fluorescence, indicating that nearly all of the increase in fluorescence could be explained by charge recombination of P800 (+)A0 (-), some of which regenerated the singlet excited state. This hypothesis was tested directly by time-resolved fluorescence studies in the ps and ns timescales. The major decay component in whole cells had a 20-ps decay time, representing trapping by the RC. Treatment of cells with dithionite resulted in the appearance of a ~18-ns decay component, which accounted for ~0.6 % of the decay, but was almost undetectable in the untreated cells. We conclude that strong illumination of heliobacterial cells can result in saturation of the electron acceptor pool, leading to reduction of the acceptor side of the RC and the creation of a back-reacting RC state that gives rise to delayed fluorescence.
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Affiliation(s)
- Kevin E Redding
- Department of Chemistry and Biochemistry, Arizona State University, 1711 S. Rural Rd., Tempe, AZ, 85287-1604, USA,
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29
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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.
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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.
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30
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Jennings RC, Zucchelli G. Ergodicity, configurational entropy and free energy in pigment solutions and plant photosystems: influence of excited state lifetime. Biophys Chem 2014; 187-188:29-32. [PMID: 24495870 DOI: 10.1016/j.bpc.2014.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/07/2014] [Accepted: 01/07/2014] [Indexed: 11/17/2022]
Abstract
We examine ergodicity and configurational entropy for a dilute pigment solution and for a suspension of plant photosystem particles in which both ground and excited state pigments are present. It is concluded that the pigment solution, due to the extreme brevity of the excited state lifetime, is non-ergodic and the configurational entropy approaches zero. Conversely, due to the rapid energy transfer among pigments, each photosystem is ergodic and the configurational entropy is positive. This decreases the free energy of the single photosystem pigment array by a small amount. On the other hand, the suspension of photosystems is non-ergodic and the configurational entropy approaches zero. The overall configurational entropy which, in principle, includes contributions from both the single excited photosystems and the suspension which contains excited photosystems, also approaches zero. Thus the configurational entropy upon photon absorption by either a pigment solution or a suspension of photosystem particles is approximately zero.
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Affiliation(s)
- Robert C Jennings
- Consiglio Nazionale delle Ricerche, Istituto di Biofisica, sede di Milano, via Giovanni Celoria 26, 20133 Milano, Italy; Dipartimento di Bioscienze, Università degli Studi di Milano, via Giovanni Celoria 26, 20133 Milano, Italy.
| | - Giuseppe Zucchelli
- Consiglio Nazionale delle Ricerche, Istituto di Biofisica, sede di Milano, via Giovanni Celoria 26, 20133 Milano, Italy; Dipartimento di Bioscienze, Università degli Studi di Milano, via Giovanni Celoria 26, 20133 Milano, Italy
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31
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Croce R, van Amerongen H. Light-harvesting in photosystem I. PHOTOSYNTHESIS RESEARCH 2013; 116:153-66. [PMID: 23645376 PMCID: PMC3825136 DOI: 10.1007/s11120-013-9838-x] [Citation(s) in RCA: 169] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 04/23/2013] [Indexed: 05/18/2023]
Abstract
This review focuses on the light-harvesting properties of photosystem I (PSI) and its LHCI outer antenna. LHCI consists of different chlorophyll a/b binding proteins called Lhca's, surrounding the core of PSI. In total, the PSI-LHCI complex of higher plants contains 173 chlorophyll molecules, most of which are there to harvest sunlight energy and to transfer the created excitation energy to the reaction center (RC) where it is used for charge separation. The efficiency of the complex is based on the capacity to deliver this energy to the RC as fast as possible, to minimize energy losses. The performance of PSI in this respect is remarkable: on average it takes around 50 ps for the excitation to reach the RC in plants, without being quenched in the meantime. This means that the internal quantum efficiency is close to 100% which makes PSI the most efficient energy converter in nature. In this review, we describe the light-harvesting properties of the complex in relation to protein and pigment organization/composition, and we discuss the important parameters that assure its very high quantum efficiency. Excitation energy transfer and trapping in the core and/or Lhcas, as well as in the supercomplexes PSI-LHCI and PSI-LHCI-LHCII are described in detail with the aim of giving an overview of the functional behavior of these complexes.
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Affiliation(s)
- Roberta Croce
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands,
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32
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Photochemical trapping heterogeneity as a function of wavelength, in plant photosystem I (PSI–LHCI). BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:779-85. [DOI: 10.1016/j.bbabio.2013.03.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 03/12/2013] [Accepted: 03/20/2013] [Indexed: 11/18/2022]
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Wientjes E, Croce R. PMS: photosystem I electron donor or fluorescence quencher. PHOTOSYNTHESIS RESEARCH 2012; 111:185-91. [PMID: 21879310 PMCID: PMC3296009 DOI: 10.1007/s11120-011-9671-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 07/07/2011] [Indexed: 05/18/2023]
Abstract
Light energy harvested by the pigments in Photosystem I (PSI) is used for charge separation in the reaction center (RC), after which the positive charge resides on a special chlorophyll dimer called P700. In studies on the PSI trapping kinetics, P700(+) is usually chemically reduced to re-open the RCs. So far, the information available about the reduction rate and possible chlorophyll fluorescence quenching effects of these reducing agents is limited. This information is indispensible to estimate the fraction of open RCs under known experimental conditions. Moreover, it would be important to understand if these reagents have a chlorophyll fluorescence quenching effects to avoid the introduction of exogenous singlet excitation quenching in the measurements. In this study, we investigated the effect of the commonly used reducing agent phenazine methosulfate (PMS) on the RC and fluorescence emission of higher plant PSI-LHCI. We measured the P700(+) reduction rate for different PMS concentrations, and show that we can give a reliable estimation on the fraction of closed RCs based on these rates. The data show that PMS is quenching chlorophyll fluorescence emission. Finally, we determined that the fluorescence quantum yield of PSI with closed RCs is 4% higher than if the RCs are open.
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Affiliation(s)
- Emilie Wientjes
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
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The role of the individual Lhcas in photosystem I excitation energy trapping. Biophys J 2011; 101:745-54. [PMID: 21806943 DOI: 10.1016/j.bpj.2011.06.045] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 06/22/2011] [Accepted: 06/24/2011] [Indexed: 11/20/2022] Open
Abstract
In this work, we have investigated the role of the individual antenna complexes and of the low-energy forms in excitation energy transfer and trapping in Photosystem I of higher plants. To this aim, a series of Photosystem I (sub)complexes with different antenna size/composition/absorption have been studied by picosecond fluorescence spectroscopy. The data show that Lhca3 and Lhca4, which harbor the most red forms, have similar emission spectra (λ(max) = 715-720 nm) and transfer excitation energy to the core with a relative slow rate of ∼25/ns. Differently, the energy transfer from Lhca1 and Lhca2, the "blue" antenna complexes, occurs about four times faster. In contrast to what is often assumed, it is shown that energy transfer from the Lhca1/4 and the Lhca2/3 dimer to the core occurs on a faster timescale than energy equilibration within these dimers. Furthermore, it is shown that all four monomers contribute almost equally to the transfer to the core and that the red forms slow down the overall trapping rate by about two times. Combining all the data allows the construction of a comprehensive picture of the excitation-energy transfer routes and rates in Photosystem I.
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35
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Wientjes E, van Stokkum IHM, van Amerongen H, Croce R. Excitation-energy transfer dynamics of higher plant photosystem I light-harvesting complexes. Biophys J 2011; 100:1372-80. [PMID: 21354411 DOI: 10.1016/j.bpj.2011.01.030] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 01/19/2011] [Indexed: 11/15/2022] Open
Abstract
Photosystem I (PSI) plays a major role in the light reactions of photosynthesis. In higher plants, PSI is composed of a core complex and four outer antennas that are assembled as two dimers, Lhca1/4 and Lhca2/3. Time-resolved fluorescence measurements on the isolated dimers show very similar kinetics. The intermonomer transfer processes are resolved using target analysis. They occur at rates similar to those observed in transfer to the PSI core, suggesting competition between the two transfer pathways. It appears that each dimer is adopting various conformations that correspond to different lifetimes and emission spectra. A special feature of the Lhca complexes is the presence of an absorption band at low energy, originating from an excitonic state of a chlorophyll dimer, mixed with a charge-transfer state. These low-energy bands have high oscillator strengths and they are superradiant in both Lhca1/4 and Lhca2/3. This challenges the view that the low-energy charge-transfer state always functions as a quencher in plant Lhc's and it also challenges previous interpretations of PSI kinetics. The very similar properties of the low-energy states of both dimers indicate that the organization of the involved chlorophylls should also be similar, in disagreement with the available structural data.
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Affiliation(s)
- Emilie Wientjes
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
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36
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Hasegawa M, Yoshida T, Yabuta M, Terazima M, Kumazaki S. Anti-Stokes Fluorescence Spectra of Chloroplasts in Parachlorella kessleri and Maize at Room Temperature as Characterized by Near-Infrared Continuous-Wave Laser Fluorescence Microscopy and Absorption Microscopy. J Phys Chem B 2011; 115:4184-94. [DOI: 10.1021/jp111306k] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Makoto Hasegawa
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takahiko Yoshida
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Mitsunori Yabuta
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Masahide Terazima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Shigeichi Kumazaki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
- PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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37
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Ferroni L, Baldisserotto C, Giovanardi M, Pantaleoni L, Morosinotto T, Pancaldi S. Revised assignment of room-temperature chlorophyll fluorescence emission bands in single living cells of Chlamydomonas reinhardtii. J Bioenerg Biomembr 2011; 43:163-73. [PMID: 21336619 DOI: 10.1007/s10863-011-9343-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 01/08/2011] [Indexed: 10/18/2022]
Abstract
Room temperature (RT) microspectrofluorimetry in vivo of single cells has a great potential in photosynthesis studies. In order to get new information on RT chlorophyll fluorescence bands, we analyzed the spectra of Chlamydomonas reinhardtii mutants lacking fundamental proteins of the thylakoid membrane and spectra of photoinhibited WT cells. RT spectra of single living cells were characterized thorough derivative analyses and Gaussian deconvolution. The results obtained suggest that the dynamism in LHCII assembly could be sufficient to explain the variations in amplitudes of F680 (free LHCII), F694 (LHCII-PSII) and F702 (LHCII aggregates); F686 was assigned to the PSII core. Based on the revised assignments and on the variations observed, we discuss the meaning of the two fluorescence emission ratios F680/(F686 + F694) and F702/(F686 + F694), showing that these are sensitive parameters under moderate photoinhibition. In the most photoinhibited samples, the RT spectra tended to degenerate, showing characteristics of mutants that are partly depleted in PSII.
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Affiliation(s)
- Lorenzo Ferroni
- Laboratory of Plant Cytophysiology, Department of Biology and Evolution, University of Ferrara, Italy
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38
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Santabarbara S, Galuppini L, Casazza AP. Bidirectional electron transfer in the reaction centre of photosystem I. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2010; 52:735-749. [PMID: 20666929 DOI: 10.1111/j.1744-7909.2010.00977.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In the past decade light-induced electron transfer reactions in photosystem I have been the subject of intensive investigations that have led to the elucidation of some unique characteristics, the most striking of which is the existence of two parallel, functional, redox active cofactors chains. This process is generally referred to as bidirectional electron transfer. Here we present a review of the principal evidences that have led to the uncovering of bidirectionality in the reaction centre of photosystem I. A special focus is dedicated to the results obtained combining time-resolved spectroscopic techniques, either difference absorption or electron paramagnetic resonance, with molecular genetics, which allows, through modification of the binding of redox active cofactors with the reaction centre subunits, an effect on their physical-chemical properties.
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39
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Passarini F, Wientjes E, van Amerongen H, Croce R. Photosystem I light-harvesting complex Lhca4 adopts multiple conformations: Red forms and excited-state quenching are mutually exclusive. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:501-8. [PMID: 20097154 DOI: 10.1016/j.bbabio.2010.01.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 01/11/2010] [Accepted: 01/14/2010] [Indexed: 10/19/2022]
Abstract
In this work we have investigated the origin of the multi-exponential fluorescence decay and of the short excited-state lifetime of Lhca4. Lhca4 is the antenna complex of Photosystem I which accommodates the red-most chlorophyll forms and it has been proposed that these chlorophylls can play a role in fluorescence quenching. Here we have compared the fluorescence decay of Lhca4 with that of several Lhca4 mutants that are affected in their red form content. The results show that neither the multi-exponentiality of the decay nor the fluorescence quenching is due to the red forms. The data indicate that Lhca4 exists in multiple conformations. The presence of the red forms, which are very sensitive to changes in the environment, allows to spectrally resolve the different conformations: a "blue" conformation with a short lifetime and a "red" one with a long lifetime. This finding strongly supports the idea that the members of the Lhc family are able to adopt different conformations associated with their light-harvesting and photoprotective roles. The ratio between the conformations is modified by the substitution of lutein by violaxanthin. Finally, it is demonstrated that the red forms cannot be present in the quenched conformation.
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Affiliation(s)
- Francesca Passarini
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
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40
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Komura M, Yamagishi A, Shibata Y, Iwasaki I, Itoh S. Mechanism of strong quenching of photosystem II chlorophyll fluorescence under drought stress in a lichen, Physciella melanchla, studied by subpicosecond fluorescence spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1797:331-8. [PMID: 19962955 DOI: 10.1016/j.bbabio.2009.11.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 11/16/2009] [Accepted: 11/25/2009] [Indexed: 10/20/2022]
Abstract
The mechanism of the severe quenching of chlorophyll (Chl) fluorescence under drought stress was studied in a lichen Physciella melanchla, which contains a photobiont green alga, Trebouxia sp., using a streak camera and a reflection-mode fluorescence up-conversion system. We detected a large 0.31 ps rise of fluorescence at 715 and 740 nm in the dry lichen suggesting the rapid energy influx to the 715-740 nm bands from the shorter-wavelength Chls with a small contribution from the internal conversion from Soret bands. The fluorescence, then, decayed with time constants of 23 and 112 ps, suggesting the rapid dissipation into heat through the quencher. The result confirms the accelerated 40 ps decay of fluorescence reported in another lichen (Veerman et al., 2007 [36]) and gives a direct evidence for the rapid energy transfer from bulk Chls to the longer-wavelength quencher. We simulated the entire PS II fluorescence kinetics by a global analysis and estimated the 20.2 ns(-1) or 55.0 ns(-1) energy transfer rate to the quencher that is connected either to the LHC II or to the PS II core antenna. The strong quenching with the 3-12 times higher rate compared to the reported NPQ rate, suggests the operation of a new type of quenching, such as the extreme case of Chl-aggregation in LHCII or a new type of quenching in PS II core antenna in dry lichens.
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Affiliation(s)
- Masayuki Komura
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8602, Japan
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41
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Abramavicius D, Mukamel S. Exciton delocalization and transport in photosystem I of cyanobacteria Synechococcus elongates: simulation study of coherent two-dimensional optical signals. J Phys Chem B 2009; 113:6097-108. [PMID: 19351124 PMCID: PMC2905166 DOI: 10.1021/jp811339p] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Electronic excitations and the optical properties of the photosynthetic complex PSI are analyzed using an effective exciton model developed by Vaitekonis et al. [Photosynth. Res. 2005, 86, 185]. States of the reaction center, the linker states, the highly delocalized antenna states and the red states are identified and assigned in absorption and circular dichroism spectra by taking into account the spectral distribution of density of exciton states, exciton delocalization length, and participation ratio in the reaction center. Signatures of exciton cooperative dynamics in nonchiral and chirality-induced two-dimensional (2D) photon-echo signals are identified. Nonchiral signals show resonances associated with the red, the reaction center, and the bulk antenna states as well as transport between them. Spectrally overlapping contributions of the linker and the delocalized antenna states are clearly resolved in the chirality-induced signals. Strong correlations are observed between the delocalized antenna states, the linker states, and the RC states. The active space of the complex covering the RC, the linker, and the delocalized antenna states is common to PSI complexes in bacteria and plants.
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Affiliation(s)
- Darius Abramavicius
- Chemistry Department, University of California Irvine, California 92697-2025, USA.
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42
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Stauber EJ, Busch A, Naumann B, Svatoš A, Hippler M. Proteotypic profiling of LHCI from Chlamydomonas reinhardtii provides new insights into structure and function of the complex. Proteomics 2009; 9:398-408. [DOI: 10.1002/pmic.200700620] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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43
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van Oort B, Amunts A, Borst JW, van Hoek A, Nelson N, van Amerongen H, Croce R. Picosecond fluorescence of intact and dissolved PSI-LHCI crystals. Biophys J 2008; 95:5851-61. [PMID: 18931256 PMCID: PMC2599838 DOI: 10.1529/biophysj.108.140467] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 09/15/2008] [Indexed: 11/18/2022] Open
Abstract
Over the past several years, many crystal structures of photosynthetic pigment-protein complexes have been determined, and these have been used extensively to model spectroscopic results obtained on the same proteins in solution. However, the crystal structure is not necessarily identical to the structure of the protein in solution. Here, we studied picosecond fluorescence of photosystem I light-harvesting complex I (PSI-LHCI), a multisubunit pigment-protein complex that catalyzes the first steps of photosynthesis. The ultrafast fluorescence of PSI-LHCI crystals is identical to that of dissolved crystals, but differs considerably from most kinetics presented in the literature. In contrast to most studies, the data presented here can be modeled quantitatively with only two compartments: PSI core and LHCI. This yields the rate of charge separation from an equilibrated core (22.5 +/- 2.5 ps) and rates of excitation energy transfer from LHCI to core (k(LC)) and vice versa (k(CL)). The ratio between these rates, R = k(CL)/k(LC), appears to be wavelength-dependent and scales with the ratio of the absorption spectra of LHCI and core, indicating the validity of a detailed balance relation between both compartments. k(LC) depends slightly but nonsystematically on detection wavelength, averaging (9.4 +/- 4.9 ps)(-1). R ranges from 0.5 (<690 nm) to approximately 1.3 above 720 nm.
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Affiliation(s)
- Bart van Oort
- Laboratory of Biophysics, Wageningen University, 6703 HA Wageningen, The Netherlands
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44
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Tumino G, Casazza AP, Engelmann E, Garlaschi FM, Zucchelli G, Jennings RC. Fluorescence Lifetime Spectrum of the Plant Photosystem II Core Complex: Photochemistry Does Not Induce Specific Reaction Center Quenching. Biochemistry 2008; 47:10449-57. [DOI: 10.1021/bi800831j] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Giorgio Tumino
- Dipartimento di Biologia, Università degli Studi di Milano and CNR Istituto di Biofisica, via Celoria 26, 20133 Milano, Italy
| | - Anna Paola Casazza
- Dipartimento di Biologia, Università degli Studi di Milano and CNR Istituto di Biofisica, via Celoria 26, 20133 Milano, Italy
| | - Enrico Engelmann
- Dipartimento di Biologia, Università degli Studi di Milano and CNR Istituto di Biofisica, via Celoria 26, 20133 Milano, Italy
| | - Flavio M. Garlaschi
- Dipartimento di Biologia, Università degli Studi di Milano and CNR Istituto di Biofisica, via Celoria 26, 20133 Milano, Italy
| | - Giuseppe Zucchelli
- Dipartimento di Biologia, Università degli Studi di Milano and CNR Istituto di Biofisica, via Celoria 26, 20133 Milano, Italy
| | - Robert C. Jennings
- Dipartimento di Biologia, Università degli Studi di Milano and CNR Istituto di Biofisica, via Celoria 26, 20133 Milano, Italy
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45
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Abstract
Time-resolved fluorescence measurements were performed on isolated core and intact Photosystem I (PS I) particles and stroma membranes from Arabidopsis thaliana to characterize the type of energy-trapping kinetics in higher plant PS I. Target analysis confirms the previously proposed "charge recombination" model. No bottleneck in the energy flow from the bulk antenna compartments to the reaction center has been found. For both particles a trap-limited kinetics is realized, with an apparent charge separation lifetime of approximately 6 ps. No red chlorophylls (Chls) are found in the PS I-core complex from A. thaliana. Rather, the observed red-shifted fluorescence (700-710 nm range) originates from the reaction center. In contrast, two red Chl compartments, located in the peripheral light-harvesting complexes, are resolved in the intact PS I particles (decay lifetimes 33 and 95 ps, respectively). These two red states have been attributed to the two red states found in Lhca 3 and Lhca 4, respectively. The influence of the red Chls on the slowing of the overall trapping kinetics in the intact PS I complex is estimated to be approximately four times larger than the effect of the bulk antenna enlargement.
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46
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Jensen PE, Bassi R, Boekema EJ, Dekker JP, Jansson S, Leister D, Robinson C, Scheller HV. Structure, function and regulation of plant photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:335-52. [PMID: 17442259 DOI: 10.1016/j.bbabio.2007.03.004] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 03/03/2007] [Accepted: 03/06/2007] [Indexed: 12/20/2022]
Abstract
Photosystem I (PSI) is a multisubunit protein complex located in the thylakoid membranes of green plants and algae, where it initiates one of the first steps of solar energy conversion by light-driven electron transport. In this review, we discuss recent progress on several topics related to the functioning of the PSI complex, like the protein composition of the complex in the plant Arabidopsis thaliana, the function of these subunits and the mechanism by which nuclear-encoded subunits can be inserted into or transported through the thylakoid membrane. Furthermore, the structure of the native PSI complex in several oxygenic photosynthetic organisms and the role of the chlorophylls and carotenoids in the antenna complexes in light harvesting and photoprotection are reviewed. The special role of the 'red' chlorophylls (chlorophyll molecules that absorb at longer wavelength than the primary electron donor P700) is assessed. The physiology and mechanism of the association of the major light-harvesting complex of photosystem II (LHCII) with PSI during short term adaptation to changes in light quality and quantity is discussed in functional and structural terms. The mechanism of excitation energy transfer between the chlorophylls and the mechanism of primary charge separation is outlined and discussed. Finally, a number of regulatory processes like acclimatory responses and retrograde signalling is reviewed with respect to function of the thylakoid membrane. We finish this review by shortly discussing the perspectives for future research on PSI.
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Affiliation(s)
- Poul Erik Jensen
- Plant Biochemistry Laboratory, Department of Plant Biology, Faculty of Life Science, University of Copenhagen, DK-1871 Frederiksberg C, Denmark.
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