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Zheng M, Pang X, Chen M, Tian L. Ultrafast energy quenching mechanism of LHCSR3-dependent photoprotection in Chlamydomonas. Nat Commun 2024; 15:4437. [PMID: 38789432 PMCID: PMC11126702 DOI: 10.1038/s41467-024-48789-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Photosynthetic organisms have evolved an essential energy-dependent quenching (qE) mechanism to avoid any lethal damages caused by high light. While the triggering mechanism of qE has been well addressed, candidates for quenchers are often debated. This lack of understanding is because of the tremendous difficulty in measuring intact cells using transient absorption techniques. Here, we have conducted femtosecond pump-probe measurements to characterize this photophysical reaction using micro-sized cell fractions of the green alga Chlamydomonas reinhardtii that retain physiological qE function. Combined with kinetic modeling, we have demonstrated the presence of an ultrafast excitation energy transfer (EET) pathway from Chlorophyll a (Chl a) Qy to a carotenoid (car) S1 state, therefore proposing that this carotenoid, likely lutein1, is the quencher. This work has provided an easy-to-prepare qE active thylakoid membrane system for advanced spectroscopic studies and demonstrated that the energy dissipation pathway of qE is evolutionarily conserved from green algae to land plants.
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Affiliation(s)
- Mengyuan Zheng
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- China National Botanical Garden, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaojie Pang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- China National Botanical Garden, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ming Chen
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- China National Botanical Garden, Beijing, 100093, China
| | - Lijin Tian
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
- China National Botanical Garden, Beijing, 100093, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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2
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Bos PR, Schiphorst C, Kercher I, Buis S, de Jong D, Vunderink I, Wientjes E. Spectral diversity of photosystem I from flowering plants. PHOTOSYNTHESIS RESEARCH 2023; 155:35-47. [PMID: 36260271 PMCID: PMC9792416 DOI: 10.1007/s11120-022-00971-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Photosystem I and II (PSI and PSII) work together to convert solar energy into chemical energy. Whilst a lot of research has been done to unravel variability of PSII fluorescence in response to biotic and abiotic factors, the contribution of PSI to in vivo fluorescence measurements has often been neglected or considered to be constant. Furthermore, little is known about how the absorption and emission properties of PSI from different plant species differ. In this study, we have isolated PSI from five plant species and compared their characteristics using a combination of optical and biochemical techniques. Differences have been identified in the fluorescence emission spectra and at the protein level, whereas the absorption spectra were virtually the same in all cases. In addition, the emission spectrum of PSI depends on temperature over a physiologically relevant range from 280 to 298 K. Combined, our data show a critical comparison of the absorption and emission properties of PSI from various plant species.
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Affiliation(s)
- Peter R Bos
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Christo Schiphorst
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Ian Kercher
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Sieka Buis
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Djanick de Jong
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Igor Vunderink
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands.
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Broddrick JT, Ware MA, Jallet D, Palsson BO, Peers G. Integration of physiologically relevant photosynthetic energy flows into whole genome models of light-driven metabolism. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 112:603-621. [PMID: 36053127 PMCID: PMC9826171 DOI: 10.1111/tpj.15965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 08/25/2022] [Accepted: 08/31/2022] [Indexed: 06/01/2023]
Abstract
Characterizing photosynthetic productivity is necessary to understand the ecological contributions and biotechnology potential of plants, algae, and cyanobacteria. Light capture efficiency and photophysiology have long been characterized by measurements of chlorophyll fluorescence dynamics. However, these investigations typically do not consider the metabolic network downstream of light harvesting. By contrast, genome-scale metabolic models capture species-specific metabolic capabilities but have yet to incorporate the rapid regulation of the light harvesting apparatus. Here, we combine chlorophyll fluorescence parameters defining photosynthetic and non-photosynthetic yield of absorbed light energy with a metabolic model of the pennate diatom Phaeodactylum tricornutum. This integration increases the model predictive accuracy regarding growth rate, intracellular oxygen production and consumption, and metabolic pathway usage. Through the quantification of excess electron transport, we uncover the sequential activation of non-radiative energy dissipation processes, cross-compartment electron shuttling, and non-photochemical quenching as the rapid photoacclimation strategy in P. tricornutum. Interestingly, the photon absorption thresholds that trigger the transition between these mechanisms were consistent at low and high incident photon fluxes. We use this understanding to explore engineering strategies for rerouting cellular resources and excess light energy towards bioproducts in silico. Overall, we present a methodology for incorporating a common, informative data type into computational models of light-driven metabolism and show its utilization within the design-build-test-learn cycle for engineering of photosynthetic organisms.
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Affiliation(s)
- Jared T. Broddrick
- Division of Biological SciencesUniversity of California, San DiegoLa JollaCA92093USA
- Department of BioengineeringUniversity of California, San DiegoLa JollaCA92093USA
- Space Biosciences Research BranchNASA Ames Research CenterMoffett FieldCA94035USA
| | - Maxwell A. Ware
- Department of BiologyColorado State UniversityFort CollinsCO80524USA
| | - Denis Jallet
- Department of BiologyColorado State UniversityFort CollinsCO80524USA
| | - Bernhard O. Palsson
- Department of BioengineeringUniversity of California, San DiegoLa JollaCA92093USA
| | - Graham Peers
- Department of BiologyColorado State UniversityFort CollinsCO80524USA
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4
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Acebron K, Salvatori N, Alberti G, Muller O, Peressotti A, Rascher U, Matsubara S. Elucidating the photosynthetic responses in chlorophyll-deficient soybean (Glycine max, L.) Cultivar. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2022. [DOI: 10.1016/j.jpap.2022.100152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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5
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Shuang SP, Zhang JY, Cun Z, Wu HM, Hong J, Chen JW. A Comparison of Photoprotective Mechanism in Different Light-Demanding Plants Under Dynamic Light Conditions. FRONTIERS IN PLANT SCIENCE 2022; 13:819843. [PMID: 35463455 PMCID: PMC9019478 DOI: 10.3389/fpls.2022.819843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Light intensity is highly heterogeneous in nature, and plants have evolved a series of strategies to acclimate to dynamic light due to their immobile lifestyles. However, it is still unknown whether there are differences in photoprotective mechanisms among different light-demanding plants in response to dynamic light, and thus the role of non-photochemical quenching (NPQ), electron transport, and light energy allocation of photosystems in photoprotection needs to be further understood in different light-demanding plants. The activities of photosystem II (PSII) and photosystem I (PSI) in shade-tolerant species Panax notoginseng, intermediate species Polygonatum kingianum, and sun-demanding species Erigeron breviscapus were comparatively measured to elucidate photoprotection mechanisms in different light-demanding plants under dynamic light. The results showed that the NPQ and PSII maximum efficiency (F v'/F m') of E. breviscapus were higher than the other two species under dynamic high light. Meanwhile, cyclic electron flow (CEF) of sun plants is larger under transient high light conditions since the slope of post-illumination, P700 dark reduction rate, and plastoquinone (PQ) pool were greater. NPQ was more active and CEF was initiated more readily in shade plants than the two other species under transient light. Moreover, sun plants processed higher quantum yield of PSII photochemistry (ΦPSII), quantum yield of photochemical energy conversion [Y(I)], and quantum yield of non-photochemical energy dissipation due to acceptor side limitation (Y(NA), while the constitutive thermal dissipation and fluorescence (Φf,d) and quantum yield of non-photochemical energy dissipation due to donor side limitation [Y(ND)] of PSI were higher in shade plants. These results suggest that sun plants had higher NPQ and CEF for photoprotection under transient high light and mainly allocated light energy through ΦPSII and ΦNPQ, while shade plants had a higher Φf,d and a larger heat dissipation efficiency of PSI donor. Overall, it has been demonstrated that the photochemical efficiency and photoprotective capacity are greater in sun plants under transient dynamic light, while shade plants are more sensitive to transient dynamic light.
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Affiliation(s)
- Sheng-Pu Shuang
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Jin-Yan Zhang
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Zhu Cun
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Hong-Min Wu
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Jie Hong
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Jun-Wen Chen
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
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6
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Quantifying the long-term interplay between photoprotection and repair mechanisms sustaining photosystem II activity. Biochem J 2022; 479:701-717. [PMID: 35234841 DOI: 10.1042/bcj20220031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 11/17/2022]
Abstract
The photosystem II reaction centre (RCII) protein subunit D1 is the main target of light-induced damage in the thylakoid membrane. As such, it is constantly replaced with newly synthesised proteins, in a process dubbed the 'D1 repair cycle'. The mechanism of relief of excitation energy pressure on RCII, non-photochemical quenching (NPQ), is activated to prevent damage. The contribution of the D1 repair cycle and NPQ in preserving the photochemical efficiency of RCII is currently unclear. In this work, we seek to (1) quantify the relative long-term effectiveness of photoprotection offered by NPQ and the D1 repair cycle, and (2) determine the fraction of sustained decrease in RCII activity that is due to long-term protective processes. We found that while under short-term, sunfleck-mimicking illumination, NPQ is substantially more effective in preserving RCII activity than the D1 repair cycle (Plant. Cell Environ. 41, 1098-1112, 2018). Under prolonged constant illumination, its contribution is less pronounced, accounting only for up to 30% of RCII protection, while D1 repair assumes a predominant role. Exposure to a wide range of light intensities yields comparable results, highlighting the crucial role of a constant and rapid D1 turnover for the maintenance of RCII efficiency. The interplay between NPQ and D1 repair cycle is crucial to grant complete phototolerance to plants under low and moderate light intensities, and limit damage to photosystem II under high light. Additionally, we disentangled and quantified the contribution of a slowly-reversible NPQ component that does not impair RCII activity, and is therefore protective.
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7
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Pfündel EE. Simultaneously measuring pulse-amplitude-modulated (PAM) chlorophyll fluorescence of leaves at wavelengths shorter and longer than 700 nm. PHOTOSYNTHESIS RESEARCH 2021; 147:345-358. [PMID: 33528756 DOI: 10.1007/s11120-021-00821-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
PAM fluorescence of leaves of cherry laurel (Prunus laurocerasus L.) was measured simultaneously in the spectral range below 700 nm (sw) and above 700 nm (lw). A high-sensitivity photodiode was employed to measure the low intensities of sw fluorescence. Photosystem II (PSII) performance was analyzed by the saturation pulse method during a light response curve with subsequent dark phase. The sw fluorescence was more variable, resulting in higher PSII photochemical yields compared to lw fluorescence. The variations between sw and lw data were explained by different levels of photosystem I (PSI) fluorescence: the contribution of PSI fluorescence to minimum fluorescence (F0) was calculated to be 14% at sw wavelengths and 45% at lw wavelengths. With the results obtained, the validity of an earlier method for the quantification of PSI fluorescence (Genty et al. in Photosynth Res 26:133-139, 1990, https://doi.org/10.1007/BF00047085 ) was reconsidered. After subtracting PSI fluorescence from all fluorescence levels, the maximum PSII photochemical yield (FV/FM) in the sw range was 0.862 and it was 0.883 in the lw range. The lower FV/FM at sw wavelengths was suggested to arise from inactive PSII reaction centers in the outermost leaf layers. Polyphasic fluorescence transients (OJIP or OI1I2P kinetics) were recorded simultaneously at sw and lw wavelengths: the slowest phase of the kinetics (IP or I2P) corresponded to 11% and 13% of total variable sw and lw fluorescence, respectively. The idea that this difference is due to variable PSI fluorescence is critically discussed. Potential future applications of simultaneously recording fluorescence in two spectral windows include studies of PSI non-photochemical quenching and state I-state II transitions, as well as measuring the fluorescence from pH-sensitive dyes simultaneously with chlorophyll fluorescence.
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Pfündel EE, Latouche G, Meister A, Cerovic ZG. Linking chloroplast relocation to different responses of photosynthesis to blue and red radiation in low and high light-acclimated leaves of Arabidopsis thaliana (L.). PHOTOSYNTHESIS RESEARCH 2018; 137:105-128. [PMID: 29374806 DOI: 10.1007/s11120-018-0482-3] [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: 09/17/2017] [Accepted: 01/09/2018] [Indexed: 05/16/2023]
Abstract
Low light (LL) and high light (HL)-acclimated plants of A. thaliana were exposed to blue (BB) or red (RR) light or to a mixture of blue and red light (BR) of incrementally increasing intensities. The light response of photosystem II was measured by pulse amplitude-modulated chlorophyll fluorescence and that of photosystem I by near infrared difference spectroscopy. The LL but not HL leaves exhibited blue light-specific responses which were assigned to relocation of chloroplasts from the dark to the light-avoidance arrangement. Blue light (BB and BR) decreased the minimum fluorescence ([Formula: see text]) more than RR light. This extra reduction of the [Formula: see text] was stronger than theoretically predicted for [Formula: see text] quenching by energy dissipation but actual measurement and theory agreed in RR treatments. The extra [Formula: see text] reduction was assigned to decreased light absorption of chloroplasts in the avoidance position. A maximum reduction of 30% was calculated. Increasing intensities of blue light affected the fluorescence parameters NPQ and qP to a lesser degree than red light. After correcting for the optical effects of chloroplast relocation, the NPQ responded similarly to blue and red light. The same correction method diminished the color-specific variations in qP but did not abolish it; thus strongly indicating the presence of another blue light effect which also moderates excitation pressure in PSII but cannot be ascribed to absorption variations. Only after RR exposure, a post-illumination overshoot of [Formula: see text] and fast oxidation of PSI electron acceptors occurred, thus, suggesting an electron flow from stromal reductants to the plastoquinone pool.
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Affiliation(s)
- Erhard E Pfündel
- Lehrstuhl für Botanik II der Universität Würzburg, Julius-von-Sachs Institut für Biowissenschaften, 97082, Würzburg, Germany.
- Heinz Walz GmbH, Eichenring 6, 91090, Effeltrich, Germany.
| | - Gwendal Latouche
- Université Paris-Saclay, Université Paris-Sud, Laboratoire Écologie Systématique et Évolution, UMR8079, Bât. 362, 91405, Orsay, France
- CNRS, 91405, Orsay, France
- AgroParisTech, 75231, Paris, France
| | - Armin Meister
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstraße 3, 06466, Gatersleben, Germany
| | - Zoran G Cerovic
- Université Paris-Saclay, Université Paris-Sud, Laboratoire Écologie Systématique et Évolution, UMR8079, Bât. 362, 91405, Orsay, France
- CNRS, 91405, Orsay, France
- AgroParisTech, 75231, Paris, France
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Ruban AV. Quantifying the efficiency of photoprotection. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0393. [PMID: 28808106 PMCID: PMC5566887 DOI: 10.1098/rstb.2016.0393] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2017] [Indexed: 12/23/2022] Open
Abstract
A novel emerging technology for the assessment of the photoprotective ‘power’ of non-photochemical fluorescence quenching (NPQ) has been reviewed and its insightful outcomes are explained using several examples. The principles of the method are described in detail as well as the work undertaken for its justification. This pulse amplitude modulated chlorophyll fluorescence approach has been applied for the past 5 years to quantify the photoprotective effectiveness of the NPQ and the light tolerance in Arabidopsis plants grown under various light conditions, during ontogenetic development as well as in a range of mutants impaired in carotenoid and protein biosynthesis. The future applications of this approach for the assessment of crop plant light tolerance are outlined. The perspective of obtaining detailed information about how the extent of photoinhibition and photoprotection can affect plant development, growth and productivity is highlighted, including the potential for us to predict the influence of environmental elements on plant performance and yield of crops. The novel methodology can be used to build up comprehensive light tolerance databases for various current and emerging varieties of crops that are grown outdoors as well as in artificial light environments, in order to optimize for the best environmental conditions that enable high crop productivity. This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement’.
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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
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10
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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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11
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Kaňa R, Govindjee. Role of Ions in the Regulation of Light-Harvesting. FRONTIERS IN PLANT SCIENCE 2016; 7:1849. [PMID: 28018387 PMCID: PMC5160696 DOI: 10.3389/fpls.2016.01849] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/23/2016] [Indexed: 03/03/2024]
Abstract
Regulation of photosynthetic light harvesting in the thylakoids is one of the major key factors affecting the efficiency of photosynthesis. Thylakoid membrane is negatively charged and influences both the structure and the function of the primarily photosynthetic reactions through its electrical double layer (EDL). Further, there is a heterogeneous organization of soluble ions (K+, Mg2+, Cl-) attached to the thylakoid membrane that, together with fixed charges (negatively charged amino acids, lipids), provides an electrical field. The EDL is affected by the valence of the ions and interferes with the regulation of "state transitions," protein interactions, and excitation energy "spillover" from Photosystem II to Photosystem I. These effects are reflected in changes in the intensity of chlorophyll a fluorescence, which is also a measure of photoprotective non-photochemical quenching (NPQ) of the excited state of chlorophyll a. A triggering of NPQ proceeds via lumen acidification that is coupled to the export of positive counter-ions (Mg2+, K+) to the stroma or/and negative ions (e.g., Cl-) into the lumen. The effect of protons and anions in the lumen and of the cations (Mg2+, K+) in the stroma are, thus, functionally tightly interconnected. In this review, we discuss the consequences of the model of EDL, proposed by Barber (1980b) Biochim Biophys Acta 594:253-308) in light of light-harvesting regulation. Further, we explain differences between electrostatic screening and neutralization, and we emphasize the opposite effect of monovalent (K+) and divalent (Mg2+) ions on light-harvesting and on "screening" of the negative charges on the thylakoid membrane; this effect needs to be incorporated in all future models of photosynthetic regulation by ion channels and transporters.
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Affiliation(s)
- Radek Kaňa
- Institute of Microbiology, Academy of Sciences of the CzechiaTřeboň, Czechia
- Faculty of Science, Institute of Chemistry and Biochemistry, University of South BohemiaČeské Budějovice, Czechia
| | - Govindjee
- Center of Biophysics and Quantitative Biology, Department of Biochemistry, Department of Plant Biology, University of Illinois at Urbana-ChampaignUrbana, IL, USA
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12
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Discerning the effects of photoinhibition and photoprotection on the rate of oxygen evolution in Arabidopsis leaves. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:272-8. [DOI: 10.1016/j.jphotobiol.2015.09.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 08/18/2015] [Accepted: 09/11/2015] [Indexed: 12/26/2022]
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13
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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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