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Wilson S, Clarke CD, Carbajal MA, Buccafusca R, Fleck RA, Daskalakis V, Ruban AV. Hydrophobic Mismatch in the Thylakoid Membrane Regulates Photosynthetic Light Harvesting. J Am Chem Soc 2024; 146:14905-14914. [PMID: 38759103 PMCID: PMC11140739 DOI: 10.1021/jacs.4c05220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/19/2024]
Abstract
The ability to harvest light effectively in a changing environment is necessary to ensure efficient photosynthesis and crop growth. One mechanism, known as qE, protects photosystem II (PSII) and regulates electron transfer through the harmless dissipation of excess absorbed photons as heat. This process involves reversible clustering of the major light-harvesting complexes of PSII (LHCII) in the thylakoid membrane and relies upon the ΔpH gradient and the allosteric modulator protein PsbS. To date, the exact role of PsbS in the qE mechanism has remained elusive. Here, we show that PsbS induces hydrophobic mismatch in the thylakoid membrane through dynamic rearrangement of lipids around LHCII leading to observed membrane thinning. We found that upon illumination, the thylakoid membrane reversibly shrinks from around 4.3 to 3.2 nm, without PsbS, this response is eliminated. Furthermore, we show that the lipid digalactosyldiacylglycerol (DGDG) is repelled from the LHCII-PsbS complex due to an increase in both the pKa of lumenal residues and in the dipole moment of LHCII, which allows for further conformational change and clustering in the membrane. Our results suggest a mechanistic role for PsbS as a facilitator of a hydrophobic mismatch-mediated phase transition between LHCII-PsbS and its environment. This could act as the driving force to sort LHCII into photoprotective nanodomains in the thylakoid membrane. This work shows an example of the key role of the hydrophobic mismatch process in regulating membrane protein function in plants.
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Affiliation(s)
- Sam Wilson
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Charlea D. Clarke
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - M. Alejandra Carbajal
- Centre
for Ultrastructural Imaging, King’s
College London, London SE1 1UL, United Kingdom
| | - Roberto Buccafusca
- Department
of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Roland A. Fleck
- Centre
for Ultrastructural Imaging, King’s
College London, London SE1 1UL, United Kingdom
| | - Vangelis Daskalakis
- Department
of Chemical Engineering, School of Engineering, University of Patras, Patras 26504, Greece
| | - Alexander V. Ruban
- Department
of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
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2
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Liu M, Wang Y, Zhang H, Hao Y, Wu H, Shen H, Zhang P. Mechanisms of photoprotection in overwintering evergreen conifers: Sustained quenching of chlorophyll fluorescence. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 210:108638. [PMID: 38653096 DOI: 10.1016/j.plaphy.2024.108638] [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: 11/12/2023] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/25/2024]
Abstract
Evergreen conifers growing in high-latitude regions must endure prolonged winters that are characterized by sub-zero temperatures combined with light, conditions that can cause significant photooxidative stress. Understanding overwintering mechanisms is crucial for addressing winter adversity in temperate forest ecosystems and enhancing the ability of conifers to adapt to climate change. This review synthesizes the current understanding of the photoprotective mechanisms that conifers employ to mitigate photooxidative stress, particularly non-photochemical "sustained quenching", the mechanism of which is hypothesized to be a recombination or deformation of the original mechanism employed by conifers in response to short-term low temperature and intense light stress in the past. Based on this hypothesis, scattered studies in this field are assembled and integrated into a complete mechanism of sustained quenching embedded in the adaptation process of plant physiology. It also reveals which parts of the whole system have been verified in conifers and which have only been verified in non-conifers, and proposes specific directions for future research. The functional implications of studies of non-coniferous plant species for the study of coniferous trees are also considered, as a wide range of plant responses lead to sustained quenching, even among different conifer species. In addition, the review highlights the challenges of measuring sustained quenching and discusses the application of ultrafast-time-resolved fluorescence and decay-associated spectra for the elucidation of photosynthetic principles.
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Affiliation(s)
- Mingyu Liu
- College of Forestry, Northeast Forestry University, Harbin, 150040, China.
| | - Yu Wang
- College of Life Sciences, Northeast Forestry University, Harbin, 150040, China.
| | - Huihui Zhang
- College of Life Sciences, Northeast Forestry University, Harbin, 150040, China.
| | - Yuanqin Hao
- College of Forestry, Northeast Forestry University, Harbin, 150040, China.
| | - Haibo Wu
- College of Forestry, Northeast Forestry University, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management, Ministry of Education, Northeast Forestry University, Harbin, 150040, China; State Forestry and Grassland Administration Engineering Technology Research Center of Korean Pine, Harbin, 150040, China.
| | - Hailong Shen
- College of Forestry, Northeast Forestry University, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management, Ministry of Education, Northeast Forestry University, Harbin, 150040, China; State Forestry and Grassland Administration Engineering Technology Research Center of Korean Pine, Harbin, 150040, China.
| | - Peng Zhang
- College of Forestry, Northeast Forestry University, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management, Ministry of Education, Northeast Forestry University, Harbin, 150040, China; State Forestry and Grassland Administration Engineering Technology Research Center of Korean Pine, Harbin, 150040, China.
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3
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Gunell S, Lempiäinen T, Rintamäki E, Aro EM, Tikkanen M. Enhanced function of non-photoinhibited photosystem II complexes upon PSII photoinhibition. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148978. [PMID: 37100340 DOI: 10.1016/j.bbabio.2023.148978] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 04/06/2023] [Accepted: 04/12/2023] [Indexed: 04/28/2023]
Abstract
Light induced photosystem (PS)II photoinhibition inactivates and irreversibly damages the reaction center protein(s) but the light harvesting complexes continue the collection of light energy. Here we addressed the consequences of such a situation on thylakoid light harvesting and electron transfer reactions. For this purpose, Arabidopsis thaliana leaves were subjected to investigation of the function and regulation of the photosynthetic machinery after a distinct portion of PSII centers had experienced photoinhibition in the presence and absence of Lincomycin (Lin), a commonly used agent to block the repair of damaged PSII centers. In the absence of Lin, photoinhibition increased the relative excitation of PSII and decreased NPQ, together enhancing the electron transfer from still functional PSII centers to PSI. In contrast, in the presence of Lin, PSII photoinhibition increased the relative excitation of PSI and led to strong oxidation of the electron transfer chain. We hypothesize that plants are able to minimize the detrimental effects of high-light illumination on PSII by modulating the energy and electron transfer, but lose such a capability if the repair cycle is arrested. It is further hypothesized that dynamic regulation of the LHCII system has a pivotal role in the control of excitation energy transfer upon PSII damage and repair cycle to maintain the photosynthesis safe and efficient.
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Affiliation(s)
- Sanna Gunell
- Molecular Plant Biology, Department of Life Technologies, University of Turku, FI-20014, Turku, Finland
| | - Tapio Lempiäinen
- Molecular Plant Biology, Department of Life Technologies, University of Turku, FI-20014, Turku, Finland
| | - Eevi Rintamäki
- Molecular Plant Biology, Department of Life Technologies, University of Turku, FI-20014, Turku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Life Technologies, University of Turku, FI-20014, Turku, Finland
| | - Mikko Tikkanen
- Molecular Plant Biology, Department of Life Technologies, University of Turku, FI-20014, Turku, Finland.
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4
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Harchouni S, England S, Vieu J, Romand S, Aouane A, Citerne S, Legeret B, Alric J, Li-Beisson Y, Menand B, Field B. Guanosine tetraphosphate (ppGpp) accumulation inhibits chloroplast gene expression and promotes super grana formation in the moss Physcomitrium (Physcomitrella) patens. THE NEW PHYTOLOGIST 2022; 236:86-98. [PMID: 35715975 DOI: 10.1111/nph.18320] [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: 03/02/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
The nucleotides guanosine tetraphosphate and pentaphosphate (or (p)ppGpp) are implicated in the regulation of chloroplast function in plants. (p)ppGpp signalling is best understood in the model vascular plant Arabidopsis thaliana in which it acts to regulate plastid gene expression to influence photosynthesis, plant development and immunity. However, little information is known about the conservation or diversity of (p)ppGpp signalling in other land plants. We studied the function of ppGpp in the moss Physcomitrium (previously Physcomitrella) patens using an inducible system for triggering ppGpp accumulation. We used this approach to investigate the effects of ppGpp on chloroplast function, photosynthesis and growth. We demonstrate that ppGpp accumulation causes a dramatic drop in photosynthetic capacity by inhibiting chloroplast gene expression. This was accompanied by the unexpected reorganisation of the thylakoid system into super grana. Surprisingly, these changes did not affect gametophore growth, suggesting that bryophytes and vascular plants may have different tolerances to defects in photosynthesis. Our findings point to the existence of both highly conserved and more specific targets of (p)ppGpp signalling in the land plants that may reflect different growth strategies.
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Affiliation(s)
- Seddik Harchouni
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, 13009, Marseille, France
| | - Samantha England
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, 13009, Marseille, France
| | - Julien Vieu
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, 13009, Marseille, France
| | - Shanna Romand
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, 13009, Marseille, France
| | - Aicha Aouane
- Aix-Marseille Université, CNRS, Institut de Biologie du Developpement de Marseille (IBDM), 13009, Marseille, France
| | - Sylvie Citerne
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000, Versailles, France
| | - Bertrand Legeret
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance, 13108, France
| | - Jean Alric
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance, 13108, France
| | - Yonghua Li-Beisson
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance, 13108, France
| | - Benoît Menand
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, 13009, Marseille, France
| | - Benjamin Field
- Aix-Marseille Université, CEA, CNRS, BIAM, UMR7265, 13009, Marseille, France
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5
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Wilson S, Li DH, Ruban AV. The Structural and Spectral Features of Light-Harvesting Complex II Proteoliposomes Mimic Those of Native Thylakoid Membranes. J Phys Chem Lett 2022; 13:5683-5691. [PMID: 35709359 PMCID: PMC9237827 DOI: 10.1021/acs.jpclett.2c01019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
The major photosystem II light-harvesting antenna (LHCII) is the most abundant membrane protein in nature and plays an indispensable role in light harvesting and photoprotection in the plant thylakoid. Here, we show that "pseudothylakoid characteristics" can be observed in artificial LHCII membranes. In our proteoliposomal system, at high LHCII densities, the liposomes become stacked, mimicking the in vivo thylakoid grana membranes. Furthermore, an unexpected, unstructured emission peak at ∼730 nm appears, similar in appearance to photosystem I emission, but with a clear excimeric character that has never been previously reported. These states correlate with the increasing density of LHCII in the membrane and a decrease in its average fluorescence lifetime. The appearance of these low-energy states can also occur in natural plant membrane structures, which has unique consequences for the interpretation of the spectroscopic and physiological properties of the photosynthetic membrane.
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6
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Ruban A, Saccon F. Chlorophyll a De-Excitation Pathways in the LHCII antenna. J Chem Phys 2022; 156:070902. [DOI: 10.1063/5.0073825] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Alexander Ruban
- SBBS, Queen Mary University of London - Mile End Campus, United Kingdom
| | - Francesco Saccon
- School of Biological and Chemical Sciences, Queen Mary University of London - Mile End Campus, United Kingdom
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7
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Mazur R, Mostowska A, Kowalewska Ł. How to Measure Grana - Ultrastructural Features of Thylakoid Membranes of Plant Chloroplasts. FRONTIERS IN PLANT SCIENCE 2021; 12:756009. [PMID: 34691132 PMCID: PMC8527009 DOI: 10.3389/fpls.2021.756009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/09/2021] [Indexed: 06/11/2023]
Abstract
Granum is a basic structural unit of the thylakoid membrane network of plant chloroplasts. It is composed of multiple flattened membranes forming a stacked arrangement of a cylindrical shape. Grana membranes are composed of lipids and tightly packed pigment-protein complexes whose primary role is the catalysis of photosynthetic light reactions. These membranes are highly dynamic structures capable of adapting to changing environmental conditions by fine-tuning photochemical efficiency, manifested by the structural reorganization of grana stacks. Due to a nanometer length scale of the structural granum features, the application of high-resolution electron microscopic techniques is essential for a detailed analysis of the granum architecture. This mini-review overviews recent approaches to quantitative grana structure analyses from electron microscopy data, highlighting the basic manual measurements and semi-automated workflows. We outline and define structural parameters used by different authors, for instance, granum height and diameter, thylakoid thickness, end-membrane length, Stacking Repeat Distance, and Granum Lateral Irregularity. This article also presents insights into efficient and effective measurements of grana stacks visualized on 2D micrographs. The information on how to correctly interpret obtained data, taking into account the 3D nature of grana stacks projected onto 2D space of electron micrograph, is also given. Grana ultrastructural observations reveal key features of this intriguing membrane arrangement, broadening our knowledge of the thylakoid network's remarkable plasticity.
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Affiliation(s)
- Radosław Mazur
- Department of Metabolic Regulation, Institute of Biochemistry, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Agnieszka Mostowska
- Department of Plant Anatomy and Cytology, Institute of Plant Experimental Biology and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Łucja Kowalewska
- Department of Plant Anatomy and Cytology, Institute of Plant Experimental Biology and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
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8
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Antenna Protein Clustering In Vitro Unveiled by Fluorescence Correlation Spectroscopy. Int J Mol Sci 2021; 22:ijms22062969. [PMID: 33804002 PMCID: PMC8000295 DOI: 10.3390/ijms22062969] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/08/2021] [Accepted: 03/11/2021] [Indexed: 12/26/2022] Open
Abstract
Antenna protein aggregation is one of the principal mechanisms considered effective in protecting phototrophs against high light damage. Commonly, it is induced, in vitro, by decreasing detergent concentration and pH of a solution of purified antennas; the resulting reduction in fluorescence emission is considered to be representative of non-photochemical quenching in vivo. However, little is known about the actual size and organization of antenna particles formed by this means, and hence the physiological relevance of this experimental approach is questionable. Here, a quasi-single molecule method, fluorescence correlation spectroscopy (FCS), was applied during in vitro quenching of LHCII trimers from higher plants for a parallel estimation of particle size, fluorescence, and antenna cluster homogeneity in a single measurement. FCS revealed that, below detergent critical micelle concentration, low pH promoted the formation of large protein oligomers of sizes up to micrometers, and therefore is apparently incompatible with thylakoid membranes. In contrast, LHCII clusters formed at high pH were smaller and homogenous, and yet still capable of efficient quenching. The results altogether set the physiological validity limits of in vitro quenching experiments. Our data also support the idea that the small, moderately quenching LHCII oligomers found at high pH could be relevant with respect to non-photochemical quenching in vivo.
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9
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Li M, Hensel G, Melzer M, Junker A, Tschiersch H, Ruwe H, Arend D, Kumlehn J, Börner T, Stein N. Mutation of the ALBOSTRIANS Ohnologous Gene HvCMF3 Impairs Chloroplast Development and Thylakoid Architecture in Barley. FRONTIERS IN PLANT SCIENCE 2021; 12:732608. [PMID: 34659298 PMCID: PMC8517540 DOI: 10.3389/fpls.2021.732608] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/10/2021] [Indexed: 05/12/2023]
Abstract
Gene pairs resulting from whole genome duplication (WGD), so-called ohnologous genes, are retained if at least one member of the pair undergoes neo- or sub-functionalization. Phylogenetic analyses of the ohnologous genes ALBOSTRIANS (HvAST/HvCMF7) and ALBOSTRIANS-LIKE (HvASL/HvCMF3) of barley (Hordeum vulgare) revealed them as members of a subfamily of genes coding for CCT motif (CONSTANS, CONSTANS-LIKE and TIMING OF CAB1) proteins characterized by a single CCT domain and a putative N-terminal chloroplast transit peptide. Recently, we showed that HvCMF7 is needed for chloroplast ribosome biogenesis. Here we demonstrate that mutations in HvCMF3 lead to seedlings delayed in development. They exhibit a yellowish/light green - xantha - phenotype and successively develop pale green leaves. Compared to wild type, plastids of mutant seedlings show a decreased PSII efficiency, impaired processing and reduced amounts of ribosomal RNAs; they contain less thylakoids and grana with a higher number of more loosely stacked thylakoid membranes. Site-directed mutagenesis of HvCMF3 identified a previously unknown functional domain, which is highly conserved within this subfamily of CCT domain containing proteins. HvCMF3:GFP fusion constructs were localized to plastids and nucleus. Hvcmf3Hvcmf7 double mutants exhibited a xantha-albino or albino phenotype depending on the strength of molecular lesion of the HvCMF7 allele. The chloroplast ribosome deficiency is discussed as the primary observed defect of the Hvcmf3 mutants. Based on our observations, the genes HvCMF3 and HvCMF7 have similar but not identical functions in chloroplast development of barley supporting our hypothesis of neo-/sub-functionalization between both ohnologous genes.
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Affiliation(s)
- Mingjiu Li
- Genomics of Genetic Resources, Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research, Seeland, Germany
| | - Goetz Hensel
- Plant Reproductive Biology, Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research, Seeland, Germany
| | - Michael Melzer
- Structural Cell Biology, Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research, Seeland, Germany
| | - Astrid Junker
- Acclimation Dynamics and Phenotyping, Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research, Seeland, Germany
| | - Henning Tschiersch
- Heterosis Research Group, Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research, Seeland, Germany
| | - Hannes Ruwe
- Molecular Genetics, Institute of Biology, Humboldt University, Berlin, Germany
| | - Daniel Arend
- Research Group Bioinformatics and Information Technology, Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research, Seeland, Germany
| | - Jochen Kumlehn
- Plant Reproductive Biology, Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research, Seeland, Germany
| | - Thomas Börner
- Molecular Genetics, Institute of Biology, Humboldt University, Berlin, Germany
- *Correspondence: Thomas Börner,
| | - Nils Stein
- Genomics of Genetic Resources, Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research, Seeland, Germany
- Department of Crop Sciences, Center for Integrated Breeding Research, Georg-August-University, Göttingen, Germany
- Nils Stein,
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10
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Saccon F, Giovagnetti V, Shukla MK, Ruban AV. Rapid regulation of photosynthetic light harvesting in the absence of minor antenna and reaction centre complexes. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3626-3637. [PMID: 32149343 PMCID: PMC7307847 DOI: 10.1093/jxb/eraa126] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/02/2020] [Indexed: 05/25/2023]
Abstract
Plants are subject to dramatic fluctuations in the intensity of sunlight throughout the day. When the photosynthetic machinery is exposed to high light, photons are absorbed in excess, potentially leading to oxidative damage of its delicate membrane components. A photoprotective molecular process called non-photochemical quenching (NPQ) is the fastest response carried out in the thylakoid membranes to harmlessly dissipate excess light energy. Despite having been intensely studied, the site and mechanism of this essential regulatory process are still debated. Here, we show that the main NPQ component called energy-dependent quenching (qE) is present in plants with photosynthetic membranes largely enriched in the major trimeric light-harvesting complex (LHC) II, while being deprived of all minor LHCs and most photosystem core proteins. This fast and reversible quenching depends upon thylakoid lumen acidification (ΔpH). Enhancing ΔpH amplifies the extent of the quenching and restores qE in the membranes lacking PSII subunit S protein (PsbS), whereas the carotenoid zeaxanthin modulates the kinetics and amplitude of the quenching. These findings highlight the self-regulatory properties of the photosynthetic light-harvesting membranes in vivo, where the ability to switch reversibly between the harvesting and dissipative states is an intrinsic property of the major LHCII.
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Affiliation(s)
- Francesco Saccon
- Queen Mary University of London, School of Biological and Chemical Sciences, London, UK
| | - Vasco Giovagnetti
- Queen Mary University of London, School of Biological and Chemical Sciences, London, UK
| | - Mahendra K Shukla
- Queen Mary University of London, School of Biological and Chemical Sciences, London, UK
| | - Alexander V Ruban
- Queen Mary University of London, School of Biological and Chemical Sciences, London, UK
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11
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Macroorganisation and flexibility of thylakoid membranes. Biochem J 2019; 476:2981-3018. [DOI: 10.1042/bcj20190080] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 09/19/2019] [Accepted: 10/03/2019] [Indexed: 02/07/2023]
Abstract
Abstract
The light reactions of photosynthesis are hosted and regulated by the chloroplast thylakoid membrane (TM) — the central structural component of the photosynthetic apparatus of plants and algae. The two-dimensional and three-dimensional arrangement of the lipid–protein assemblies, aka macroorganisation, and its dynamic responses to the fluctuating physiological environment, aka flexibility, are the subject of this review. An emphasis is given on the information obtainable by spectroscopic approaches, especially circular dichroism (CD). We briefly summarise the current knowledge of the composition and three-dimensional architecture of the granal TMs in plants and the supramolecular organisation of Photosystem II and light-harvesting complex II therein. We next acquaint the non-specialist reader with the fundamentals of CD spectroscopy, recent advances such as anisotropic CD, and applications for studying the structure and macroorganisation of photosynthetic complexes and membranes. Special attention is given to the structural and functional flexibility of light-harvesting complex II in vitro as revealed by CD and fluorescence spectroscopy. We give an account of the dynamic changes in membrane macroorganisation associated with the light-adaptation of the photosynthetic apparatus and the regulation of the excitation energy flow by state transitions and non-photochemical quenching.
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12
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Fine tuning of the photosystem II major antenna mobility within the thylakoid membrane of higher plants. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:183059. [PMID: 31518553 DOI: 10.1016/j.bbamem.2019.183059] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 08/16/2019] [Accepted: 09/04/2019] [Indexed: 12/15/2022]
Abstract
Depending on the amount of light, the photosystem II (PSII) antennae or Light Harvesting Complexes (LHCII) switch between two states within the thylakoid membranes of higher plants, i.e., a light-harvesting and a photoprotective mode. This switch is co-regulated by a pH gradient (ΔpH) across the membrane and the interaction with the PSII subunit S (PsbS) that is proposed to induce LHCII aggregation. Herein we employ all-atom and coarse-grained molecular simulations of the major LHCII trimer at low and excess ΔpH, as well as in complexation with PsbS within a native thylakoid membrane model. Our results demonstrate the aggregation potential of LHCII and, consistent with the experimental literature, reveal the role of PsbS at atomic resolution. PsbS alters the LHCII-thylakoid lipid interactions and restores the LHCII mobility that is lost in the transition to photoprotective conditions (low lumenal pH). In agreement with this finding, diffusion of the integral membrane protein LHCII is dependent on both, electrostatic interactions and hydrophobic mismatch, while it does not obey the Saffman-Delbrück diffusion model.
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13
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Kaňa R, Kotabová E, Šedivá B, Kuthanová Trsková E. Photoprotective strategies in the motile cryptophyte alga Rhodomonas salina-role of non-photochemical quenching, ions, photoinhibition, and cell motility. Folia Microbiol (Praha) 2019; 64:691-703. [PMID: 31352667 DOI: 10.1007/s12223-019-00742-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022]
Abstract
We explored photoprotective strategies in a cryptophyte alga Rhodomonas salina. This cryptophytic alga represents phototrophs where chlorophyll a/c antennas in thylakoids are combined with additional light-harvesting system formed by phycobiliproteins in the chloroplast lumen. The fastest response to excessive irradiation is induction of non-photochemical quenching (NPQ). The maximal NPQ appears already after 20 s of excessive irradiation. This initial phase of NPQ is sensitive to Ca2+ channel inhibitor (diltiazem) and disappears, also, in the presence of non-actin, an ionophore for monovalent cations. The prolonged exposure to high light of R. salina cells causes photoinhibition of photosystem II (PSII) that can be further enhanced when Ca2+ fluxes are inhibited by diltiazem. The light-induced reduction in PSII photochemical activity is smaller when compared with immotile diatom Phaeodactylum tricornutum. We explain this as a result of their different photoprotective strategies. Besides the protective role of NPQ, the motile R. salina also minimizes high light exposure by increased cell velocity by almost 25% percent (25% from 82 to 104 μm/s). We suggest that motility of algal cells might have a photoprotective role at high light because algal cell rotation around longitudinal axes changes continual irradiation to periodically fluctuating light.
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Affiliation(s)
- Radek Kaňa
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic.
| | - Eva Kotabová
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic
| | - Barbora Šedivá
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic
| | - Eliška Kuthanová Trsková
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic.,Student of Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, Ceske Budejovice, Czech Republic
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14
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Lima-Melo Y, Gollan PJ, Tikkanen M, Silveira JAG, Aro EM. Consequences of photosystem-I damage and repair on photosynthesis and carbon use in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:1061-1072. [PMID: 30488561 DOI: 10.1111/tpj.14177] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 05/26/2023]
Abstract
Natural growth environments commonly include fluctuating conditions that can disrupt the photosynthetic energy balance and induce photoinhibition through inactivation of the photosynthetic apparatus. Photosystem II (PSII) photoinhibition is efficiently reversed by the PSII repair cycle, whereas photoinhibited photosystem I (PSI) recovers much more slowly. In the current study, treatment of the Arabidopsis thaliana mutant proton gradient regulation 5 (pgr5) with excess light was used to compromise PSI functionality in order to investigate the impact of photoinhibition and subsequent recovery on photosynthesis and carbon metabolism. The negative impact of PSI photoinhibition on CO2 fixation was especially deleterious under low irradiance. Impaired starch accumulation after PSI photoinhibition was reflected in reduced respiration in the dark, but this was not attributed to impaired sugar synthesis. Normal chloroplast and mitochondrial metabolisms were shown to recover despite the persistence of substantial PSI photoinhibition for several days. The results of this study indicate that the recovery of PSI function involves the reorganization of the light-harvesting antennae, and suggest a pool of surplus PSI that can be recruited to support photosynthesis under demanding conditions.
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Affiliation(s)
- Yugo Lima-Melo
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP 60440-900, Fortaleza, CE, Brazil
| | - Peter J Gollan
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Mikko Tikkanen
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Joaquim A G Silveira
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP 60440-900, Fortaleza, CE, Brazil
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
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15
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Ruban AV. Light harvesting control in plants. FEBS Lett 2018; 592:3030-3039. [PMID: 29797317 DOI: 10.1002/1873-3468.13111] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/30/2018] [Accepted: 05/18/2018] [Indexed: 01/02/2023]
Abstract
In 1991, my colleagues and I published a hypothesis article that proposed a mechanism that controls light harvesting in plants and protects them against photodamage. The major light harvesting complex, LHCII, was suggested to undergo aggregation upon exposure of the plant to damaging levels of light. Aggregated LHCII was found to be much less efficient in light harvesting, as it promptly dissipated absorbed energy into heat, possessing a very low chlorophyll fluorescence yield. Nonphotochemical quenching (NPQ) is a term coined to describe this reduction in chlorophyll fluorescence yield. This article is a story of how the hypothesis that LHCII aggregation is involved in NPQ is developed into a model that is now becoming broadly accepted by the research community.
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Affiliation(s)
- Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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16
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Townsend AJ, Ware MA, Ruban AV. Dynamic interplay between photodamage and photoprotection in photosystem II. PLANT, CELL & ENVIRONMENT 2018; 41:1098-1112. [PMID: 29210070 DOI: 10.1111/pce.13107] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/20/2017] [Accepted: 11/21/2017] [Indexed: 06/07/2023]
Abstract
Photoinhibition is the light-induced reduction in photosynthetic efficiency and is usually associated with damage to the D1 photosystem II (PSII) reaction centre protein. This damage must either be repaired, through the PSII repair cycle, or prevented in the first place by nonphotochemical quenching (NPQ). Both NPQ and D1 repair contribute to light tolerance because they ensure the long-term maintenance of the highest quantum yield of PSII. However, the relative contribution of each of these processes is yet to be elucidated. The application of a pulse amplitude modulation fluorescence methodology, called protective NPQ, enabled us to evaluate of the protective effectiveness of the processes. Within this study, the contribution of NPQ and D1 repair to the photoprotective capacity of Arabidopsis thaliana was elucidated by using inhibitors and mutants known to affect each process. We conclude that NPQ contributes a greater amount to the maintenance of a high PSII yield than D1 repair under short periods of illumination. This research further supports the role of protective components of NPQ during light fluctuations and the value of protective NPQ and qPd as unambiguous fluorescence parameters, as opposed to qI and Fv /Fm , for quantifying photoinactivation of reaction centre II and light tolerance of photosynthetic organisms.
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Affiliation(s)
- Alexandra J Townsend
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E14NS, UK
| | - Maxwell A Ware
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E14NS, UK
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E14NS, UK
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17
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Townsend AJ, Saccon F, Giovagnetti V, Wilson S, Ungerer P, Ruban AV. The causes of altered chlorophyll fluorescence quenching induction in the Arabidopsis mutant lacking all minor antenna complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:666-675. [PMID: 29548769 DOI: 10.1016/j.bbabio.2018.03.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/01/2018] [Accepted: 03/10/2018] [Indexed: 01/18/2023]
Abstract
Non-photochemical quenching (NPQ) of chlorophyll fluorescence is the process by which excess light energy is harmlessly dissipated within the photosynthetic membrane. The fastest component of NPQ, known as energy-dependent quenching (qE), occurs within minutes, but the site and mechanism of qE remain of great debate. Here, the chlorophyll fluorescence of Arabidopsis thaliana wild type (WT) plants was compared to mutants lacking all minor antenna complexes (NoM). Upon illumination, NoM exhibits altered chlorophyll fluorescence quenching induction (i.e. from the dark-adapted state) characterised by three different stages: (i) a fast quenching component, (ii) transient fluorescence recovery and (iii) a second quenching component. The initial fast quenching component originates in light harvesting complex II (LHCII) trimers and is dependent upon PsbS and the formation of a proton gradient across the thylakoid membrane (ΔpH). Transient fluorescence recovery is likely to occur in both WT and NoM plants, but it cannot be overcome in NoM due to impaired ΔpH formation and a reduced zeaxanthin synthesis rate. Moreover, an enhanced fluorescence emission peak at ~679 nm in NoM plants indicates detachment of LHCII trimers from the bulk antenna system, which could also contribute to the transient fluorescence recovery. Finally, the second quenching component is triggered by both ΔpH and PsbS and enhanced by zeaxanthin synthesis. This study indicates that minor antenna complexes are not essential for qE, but reveals their importance in electron stransport, ΔpH formation and zeaxanthin synthesis.
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Affiliation(s)
- Alexandra J Townsend
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK
| | - Francesco Saccon
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK
| | - Vasco Giovagnetti
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK
| | - Sam Wilson
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK
| | - Petra Ungerer
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK.
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18
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Belgio E, Trsková E, Kotabová E, Ewe D, Prášil O, Kaňa R. High light acclimation of Chromera velia points to photoprotective NPQ. PHOTOSYNTHESIS RESEARCH 2018; 135:263-274. [PMID: 28405863 DOI: 10.1007/s11120-017-0385-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 04/06/2017] [Indexed: 05/13/2023]
Abstract
It has previously been shown that the long-term treatment of Arabidopsis thaliana with the chloroplast inhibitor lincomycin leads to photosynthetic membranes enriched in antennas, strongly reduced in photosystem II reaction centers (PSII) and with enhanced nonphotochemical quenching (NPQ) (Belgio et al. Biophys J 102:2761-2771, 2012). Here, a similar physiological response was found in the microalga Chromera velia grown under high light (HL). In comparison to cells acclimated to low light, HL cells displayed a severe re-organization of the photosynthetic membrane characterized by (1) a reduction of PSII but similar antenna content; (2) partial uncoupling of antennas from PSII; (3) enhanced NPQ. The decrease in the number of PSII represents a rather unusual acclimation response compared to other phototrophs, where a smaller PSII antenna size is more commonly found under high light. Despite the diminished PSII content, no net damage could be detected on the basis of the Photosynthesis versus irradiance curve and electron transport rates pointing at the excess capacity of PSII. We therefore concluded that the photoinhibition is minimized under high light by a lower PSII content and that cells are protected by NPQ in the antennas.
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Affiliation(s)
- Erica Belgio
- Centre Algatech, Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81, Třeboň, Czech Republic.
| | - Eliška Trsková
- Centre Algatech, Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005, Czech Budejovice, Czech Republic
| | - Eva Kotabová
- Centre Algatech, Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81, Třeboň, Czech Republic
| | - Daniela Ewe
- Centre Algatech, Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81, Třeboň, Czech Republic
| | - Ondřej Prášil
- Centre Algatech, Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005, Czech Budejovice, Czech Republic
| | - Radek Kaňa
- Centre Algatech, Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005, Czech Budejovice, Czech Republic
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19
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Wood WHJ, MacGregor-Chatwin C, Barnett SFH, Mayneord GE, Huang X, Hobbs JK, Hunter CN, Johnson MP. Dynamic thylakoid stacking regulates the balance between linear and cyclic photosynthetic electron transfer. NATURE PLANTS 2018; 4:116-127. [PMID: 29379151 DOI: 10.1038/s41477-017-0092-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 12/13/2017] [Indexed: 05/05/2023]
Abstract
Upon transition of plants from darkness to light the initiation of photosynthetic linear electron transfer (LET) from H2O to NADP+ precedes the activation of CO2 fixation, creating a lag period where cyclic electron transfer (CET) around photosystem I (PSI) has an important protective role. CET generates ΔpH without net reduced NADPH formation, preventing overreduction of PSI via regulation of the cytochrome b 6 f (cytb 6 f) complex and protecting PSII from overexcitation by inducing non-photochemical quenching. The dark-to-light transition also provokes increased phosphorylation of light-harvesting complex II (LHCII). However, the relationship between LHCII phosphorylation and regulation of the LET/CET balance is not understood. Here, we show that the dark-to-light changes in LHCII phosphorylation profoundly alter thylakoid membrane architecture and the macromolecular organization of the photosynthetic complexes, without significantly affecting the antenna size of either photosystem. The grana diameter and number of membrane layers per grana are decreased in the light while the number of grana per chloroplast is increased, creating a larger contact area between grana and stromal lamellae. We show that these changes in thylakoid stacking regulate the balance between LET and CET pathways. Smaller grana promote more efficient LET by reducing the diffusion distance for the mobile electron carriers plastoquinone and plastocyanin, whereas larger grana enhance the partition of the granal and stromal lamellae plastoquinone pools, enhancing the efficiency of CET and thus photoprotection by non-photochemical quenching.
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Affiliation(s)
- William H J Wood
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | | | - Samuel F H Barnett
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Guy E Mayneord
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Xia Huang
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Jamie K Hobbs
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK.
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20
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Albanese P, Melero R, Engel BD, Grinzato A, Berto P, Manfredi M, Chiodoni A, Vargas J, Sorzano CÓS, Marengo E, Saracco G, Zanotti G, Carazo JM, Pagliano C. Pea PSII-LHCII supercomplexes form pairs by making connections across the stromal gap. Sci Rep 2017; 7:10067. [PMID: 28855679 PMCID: PMC5577252 DOI: 10.1038/s41598-017-10700-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/14/2017] [Indexed: 12/30/2022] Open
Abstract
In higher plant thylakoids, the heterogeneous distribution of photosynthetic protein complexes is a determinant for the formation of grana, stacks of membrane discs that are densely populated with Photosystem II (PSII) and its light harvesting complex (LHCII). PSII associates with LHCII to form the PSII-LHCII supercomplex, a crucial component for solar energy conversion. Here, we report a biochemical, structural and functional characterization of pairs of PSII-LHCII supercomplexes, which were isolated under physiologically-relevant cation concentrations. Using single-particle cryo-electron microscopy, we determined the three-dimensional structure of paired C2S2M PSII-LHCII supercomplexes at 14 Å resolution. The two supercomplexes interact on their stromal sides through a specific overlap between apposing LHCII trimers and via physical connections that span the stromal gap, one of which is likely formed by interactions between the N-terminal loops of two Lhcb4 monomeric LHCII subunits. Fast chlorophyll fluorescence induction analysis showed that paired PSII-LHCII supercomplexes are energetically coupled. Molecular dynamics simulations revealed that additional flexible physical connections may form between the apposing LHCII trimers of paired PSII-LHCII supercomplexes in appressed thylakoid membranes. Our findings provide new insights into how interactions between pairs of PSII-LHCII supercomplexes can link adjacent thylakoids to mediate the stacking of grana membranes.
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Affiliation(s)
- Pascal Albanese
- Applied Science and Technology Department-BioSolar Lab, Politecnico di Torino, Viale T. Michel 5, 15121, Alessandria, Italy
- Department of Biology, University of Padova, Via Ugo Bassi 58 B, 35121, Padova, Italy
| | - Roberto Melero
- Biocomputing Unit, Centro Nacional de Biotecnología-CSIC, Darwin 3, Cantoblanco, 28049, Madrid, Spain
| | - Benjamin D Engel
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Alessandro Grinzato
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58 B, 35121, Padova, Italy
| | - Paola Berto
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58 B, 35121, Padova, Italy
| | - Marcello Manfredi
- ISALIT-Department of Science and Technological Innovation, University of Eastern Piedmont, Viale T. Michel 11, 15121, Alessandria, Italy
- Department of Science and Technological Innovation, University of Eastern Piedmont, Viale T. Michel 11, 15121, Alessandria, Italy
| | - Angelica Chiodoni
- Center for Sustainable Future Technologies - CSFT@POLITO, Istituto Italiano di Tecnologia, Corso Trento 21, 10129, Torino, Italy
| | - Javier Vargas
- Biocomputing Unit, Centro Nacional de Biotecnología-CSIC, Darwin 3, Cantoblanco, 28049, Madrid, Spain
| | | | - Emilio Marengo
- Department of Science and Technological Innovation, University of Eastern Piedmont, Viale T. Michel 11, 15121, Alessandria, Italy
| | - Guido Saracco
- Center for Sustainable Future Technologies - CSFT@POLITO, Istituto Italiano di Tecnologia, Corso Trento 21, 10129, Torino, Italy
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58 B, 35121, Padova, Italy
| | - Jose-Maria Carazo
- Biocomputing Unit, Centro Nacional de Biotecnología-CSIC, Darwin 3, Cantoblanco, 28049, Madrid, Spain
| | - Cristina Pagliano
- Applied Science and Technology Department-BioSolar Lab, Politecnico di Torino, Viale T. Michel 5, 15121, Alessandria, Italy.
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21
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Tian Y, Ungerer P, Zhang H, Ruban AV. Direct impact of the sustained decline in the photosystem II efficiency upon plant productivity at different developmental stages. JOURNAL OF PLANT PHYSIOLOGY 2017; 212:45-53. [PMID: 28260626 DOI: 10.1016/j.jplph.2016.10.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 10/28/2016] [Accepted: 10/28/2016] [Indexed: 06/06/2023]
Abstract
The impact of chronic photoinhibition of photosystem II (PSII) on the productivity of plants remains unknown. The present study investigated the influences of persistent decline in the PSII yield on morphology and productivity of Arabidopsis plants that were exposed to lincomycin at two different developmental stages (seedling and rosette stage). The results indicated that, although retarded, the lincomycin treated plants were able to accomplish the entire growth period with only 50% of the maximum quantum yield of primary photochemistry (Fv/Fm) of the control plants. The decline in quantum yield limited the electron transport rate (ETR). The impact of lincomycin on NPQ was not significant in seedlings, but was pronounced in mature plants. The treated plants produced an above ground biomass of 50% compared to control plants. Moreover, a linear relationship was found between the above ground biomass and total rosette leaf area, and the slope was decreased due to photoinhibition. The starch accumulation was highly inhibited by lincomycin treatment. Lincomycin induced a significant decrease in seed yield with plants treated from the rosette state showing higher yield than those treated from the seedling stage. Our data suggest that the sustained decline of PSII efficiency decreases plant productivity by constraining the ETR, leaf development and starch production.
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Affiliation(s)
- Yonglan Tian
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK; Research Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing 102206, China
| | - Petra Ungerer
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Huayong Zhang
- Research Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing 102206, China
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK.
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22
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Sacharz J, Giovagnetti V, Ungerer P, Mastroianni G, Ruban AV. The xanthophyll cycle affects reversible interactions between PsbS and light-harvesting complex II to control non-photochemical quenching. NATURE PLANTS 2017; 3:16225. [PMID: 28134919 DOI: 10.1038/nplants.2016.225] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/22/2016] [Indexed: 05/19/2023]
Abstract
To maintain high photosynthetic rates, plants must adapt to their light environment on a timescale of seconds to minutes. Therefore, the light-harvesting antenna system of photosystem II in thylakoid membranes, light-harvesting complex II (LHCII), has a feedback mechanism, which determines the proportion of absorbed energy dissipated as heat: non-photochemical chlorophyll fluorescence quenching (NPQ). This is crucial to prevent photo-oxidative damage to photosystem II (PSII) and is controlled by the transmembrane pH differences (ΔpH). High ΔpH activates NPQ by protonation of the protein PsbS and the enzymatic de-epoxidation of LHCII-bound violaxanthin to zeaxanthin. But the precise role of PsbS and its interactions with different LHCII complexes remain uncertain. We have investigated PsbS-LHCII interactions in native thylakoid membranes using magnetic-bead-linked antibody pull-downs. The interaction of PsbS with the antenna system is affected by both ΔpH and the level of zeaxanthin. In the presence of ΔpH alone, PsbS is found to be mainly associated with the trimeric LHCII protein polypeptides, Lhcb1, Lhcb2 and Lhcb3. However, a combination of ΔpH and zeaxanthin increases the proportion of PsbS bound to the minor LHCII antenna complex proteins Lhcb4, Lhcb5 and Lhcb6. This pattern of interaction is not influenced by the presence of PSII reactions centres. Similar to LHCII particles in the photosynthetic membrane, PsbS protein forms clusters in the NPQ state. NPQ recovery in the dark requires uncoupling of PsbS. We suggest that PsbS acts as a 'seeding' centre for the LHCII antenna rearrangement that is involved in NPQ.
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Affiliation(s)
- Joanna Sacharz
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Vasco Giovagnetti
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Petra Ungerer
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Giulia Mastroianni
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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23
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Pinnola A, Staleva-Musto H, Capaldi S, Ballottari M, Bassi R, Polívka T. Electron transfer between carotenoid and chlorophyll contributes to quenching in the LHCSR1 protein from Physcomitrella patens. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:1870-1878. [PMID: 27614061 DOI: 10.1016/j.bbabio.2016.09.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/27/2016] [Accepted: 09/06/2016] [Indexed: 10/21/2022]
Abstract
Plants harvest photons for photosynthesis using light-harvesting complexes (LHCs)-an array of chlorophyll proteins that can reversibly switch from harvesting to energy-dissipation mode to prevent over-excitation and damage of the photosynthetic apparatus. In unicellular algae and lower plants this process requires the LHCSR proteins which senses over-acidification of the lumen trough protonatable residues exposed to the thylakoid lumen to activate quenching reactions. Further activation is provided by replacement of the violaxanthin ligand with its de-epoxidized product, zeaxanthin, also induced by excess light. We have produced the ppLHCSR1 protein from Physcomitrella patens by over-expression in tobacco and purified it in either its violaxanthin- or the zeaxanthin-binding form with the aim of analyzing their spectroscopic properties at either neutral or acidic pH. Using femtosecond spectroscopy, we demonstrated that the energy dissipation is achieved by two distinct quenching mechanism which are both activated by low pH. The first is present in both ppLHCSR1-Vio and ppLHCSR1-Zea and is characterized by 30-40ps time constant. The spectrum of the quenching product is reminiscent of a carotenoid radical cation, suggesting that the pH-induced quenching mechanism is likely electron transfer from the carotenoid to the excited Chl a. In addition, a second quenching channel populating the S1 state of carotenoid via energy transfer from Chl is found exclusively in the ppLHCSR1-Zea at pH5. These results provide proof of principle that more than one quenching mechanism may operate in the LHC superfamily and also help understanding the photoprotective role of LHCSR proteins and the evolution of LHC antennae.
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Affiliation(s)
- Alberta Pinnola
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Hristina Staleva-Musto
- Institute of Physics and Biophysics, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
| | - Stefano Capaldi
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Matteo Ballottari
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Roberto Bassi
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Tomáš Polívka
- Institute of Physics and Biophysics, Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic; Institute of Plant Molecular Biology, Biology Centre, Czech Academy of Sciences, Branišovská 31, České Budějovice, Czech Republic.
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24
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Fujii R, Yamano N, Hashimoto H, Misawa N, Ifuku K. Photoprotection vs. Photoinhibition of Photosystem II in Transplastomic Lettuce (Lactuca sativa) Dominantly Accumulating Astaxanthin. PLANT & CELL PHYSIOLOGY 2016; 57:1518-1529. [PMID: 26644463 DOI: 10.1093/pcp/pcv187] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 11/18/2015] [Indexed: 06/05/2023]
Abstract
Transplastomic (chloroplast genome-modified; CGM) lettuce that dominantly accumulates astaxanthin grows similarly to a non-transgenic control with almost no accumulation of naturally occurring photosynthetic carotenoids. In this study, we evaluated the activity and assembly of PSII in CGM lettuce. The maximum quantum yield of PSII in CGM lettuce was <0.6; however, the quantum yield of PSII was comparable with that in control leaves under higher light intensity. CGM lettuce showed a lower ability to induce non-photochemical quenching (NPQ) than the control under various light intensities. The fraction of slowly recovering NPQ in CGM lettuce, which is considered to be photoinhibitory quenching (qI), was less than half that of the control. In fact, 1O2 generation was lower in CGM than in control leaves under high light intensity. CGM lettuce contained less PSII, accumulated mostly as a monomer in thylakoid membranes. The PSII monomers purified from the CGM thylakoids bound echinenone and canthaxanthin in addition to β-carotene, suggesting that a shortage of β-carotene and/or the binding of carbonyl carotenoids would interfere with the photophysical function as well as normal assembly of PSII. In contrast, high accumulation of astaxanthin and other carbonyl carotenoids was found within the thylakoid membranes. This finding would be associated with the suppression of photo-oxidative stress in the thylakoid membranes. Our observation suggests the importance of a specific balance between photoprotection and photoinhibition that can support normal photosynthesis in CGM lettuce producing astaxanthin.
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Affiliation(s)
- Ritsuko Fujii
- The Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka, 558-8585 Japan
- Graduate School of Science, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka, 558-8585 Japan
- JST, PRESTO, 4-1-8 Honcho Kawaguchi, Saitama, 332-0012 Japan
| | - Nami Yamano
- Graduate School of Science, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka, 558-8585 Japan
| | - Hideki Hashimoto
- The Osaka City University Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka, 558-8585 Japan
- Graduate School of Science, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka, 558-8585 Japan
- Present address: Department of Applied Chemistry for Environment, Graduate School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337 Japan
| | - Norihiko Misawa
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi-Shi Ishikawa, 921-8836 Japan
| | - Kentaro Ifuku
- Graduate School of Biostudies, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502 Japan
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25
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Charuvi D, Nevo R, Kaplan-Ashiri I, Shimoni E, Reich Z. Studying the Supramolecular Organization of Photosynthetic Membranes within Freeze-fractured Leaf Tissues by Cryo-scanning Electron Microscopy. J Vis Exp 2016:54066. [PMID: 27403565 PMCID: PMC4993236 DOI: 10.3791/54066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Cryo-scanning electron microscopy (SEM) of freeze-fractured samples allows investigation of biological structures at near native conditions. Here, we describe a technique for studying the supramolecular organization of photosynthetic (thylakoid) membranes within leaf samples. This is achieved by high-pressure freezing of leaf tissues, freeze-fracturing, double-layer coating and finally cryo-SEM imaging. Use of the double-layer coating method allows acquiring high magnification (>100,000X) images with minimal beam damage to the frozen-hydrated samples as well as minimal charging effects. Using the described procedures we investigated the alterations in supramolecular distribution of photosystem and light-harvesting antenna protein complexes that take place during dehydration of the resurrection plant Craterostigma pumilum, in situ.
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Affiliation(s)
- Dana Charuvi
- Department of Biological Chemistry, Weizmann Institute of Science; Institute of Plant Sciences, Agricultural Research Organization, Volcani Center;
| | - Reinat Nevo
- Department of Biological Chemistry, Weizmann Institute of Science
| | | | - Eyal Shimoni
- Department of Chemical Research Support, Weizmann Institute of Science
| | - Ziv Reich
- Department of Biological Chemistry, Weizmann Institute of Science
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26
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Ruban AV, Johnson MP. Visualizing the dynamic structure of the plant photosynthetic membrane. NATURE PLANTS 2015; 1:15161. [PMID: 27251532 DOI: 10.1038/nplants.2015.161] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 09/29/2015] [Indexed: 05/28/2023]
Abstract
The chloroplast thylakoid membrane is the site for the initial steps of photosynthesis that convert solar energy into chemical energy, ultimately powering almost all life on earth. The heterogeneous distribution of protein complexes within the membrane gives rise to an intricate three-dimensional structure that is nonetheless extremely dynamic on a timescale of seconds to minutes. These dynamics form the basis for the regulation of photosynthesis, and therefore the adaptability of plants to different environments. High-resolution microscopy has in recent years begun to provide new insights into the structural dynamics underlying a number of regulatory processes such as membrane stacking, photosystem II repair, photoprotective energy dissipation, state transitions and alternative electron transfer. Here we provide an overview of the essentials of thylakoid membrane structure in plants, and consider how recent advances, using a range of microscopies, have substantially increased our knowledge of the thylakoid dynamic structure. We discuss both the successes and limitations of the currently available techniques and highlight newly emerging microscopic methods that promise to move the field beyond the current 'static' view of membrane organization based on frozen snapshots to a 'live' view of functional membranes imaged under native aqueous conditions at ambient temperature and responding dynamically to external stimuli.
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Affiliation(s)
- Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK
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27
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Ware MA, Giovagnetti V, Belgio E, Ruban AV. PsbS protein modulates non-photochemical chlorophyll fluorescence quenching in membranes depleted of photosystems. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:301-7. [PMID: 26233261 DOI: 10.1016/j.jphotobiol.2015.07.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 01/21/2023]
Abstract
Plants with varying levels of PsbS protein were grown on lincomycin. Enhanced levels of non-photochemical fluorescence quenching (NPQ) in over-expressers of the protein have been observed. This was accompanied by increased amplitude of the irreversible NPQ component, qI, previously considered to reflect mainly photoinhibition of PSII reaction centres (RCII). However, since RCIIs were largely absent the observed qI is likely to originate from the LHCII antenna. In chloroplasts of over-expressers of PsbS grown on lincomycin an abnormally large NPQ (∼7) was characterised by a 0.34 ns average chlorophyll fluorescence lifetime. Yet the lifetime in the Fm state was similar to that of wild-type plants. 77K fluorescence emission spectra revealed a specific 700 nm peak typical of LHCII aggregates as well as quenching of the PSI fluorescence at 730 nm. The aggregated state manifested itself as a clear change in the distance between LHCII complexes detected by freeze-fracture electron microscopy. Grana thylakoids in the quenched state revealed 3 times more aggregated LHCII particles compared to the dark-adapted state. Overall, the results directly demonstrate the importance of LHCII aggregation in the NPQ mechanism and show that the PSII supercomplex structure plays no role in formation of the observed quenching.
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Affiliation(s)
- Maxwell A Ware
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Vasco Giovagnetti
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Erica Belgio
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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