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Zavřel T, Segečová A, Kovács L, Lukeš M, Novák Z, Pohland AC, Szabó M, Somogyi B, Prášil O, Červený J, Bernát G. A Comprehensive Study of Light Quality Acclimation in Synechocystis Sp. PCC 6803. PLANT & CELL PHYSIOLOGY 2024; 65:1285-1297. [PMID: 38907526 PMCID: PMC11369814 DOI: 10.1093/pcp/pcae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 05/13/2024] [Accepted: 05/27/2024] [Indexed: 06/24/2024]
Abstract
Cyanobacteria play a key role in primary production in both oceans and fresh waters and hold great potential for sustainable production of a large number of commodities. During their life, cyanobacteria cells need to acclimate to a multitude of challenges, including shifts in intensity and quality of incident light. Despite our increasing understanding of metabolic regulation under various light regimes, detailed insight into fitness advantages and limitations under shifting light quality remains underexplored. Here, we study photo-physiological acclimation in the cyanobacterium Synechocystis sp. PCC 6803 throughout the photosynthetically active radiation (PAR) range. Using light emitting diodes (LEDs) with qualitatively different narrow spectra, we describe wavelength dependence of light capture, electron transport and energy transduction to main cellular pools. In addition, we describe processes that fine-tune light capture, such as state transitions, or the efficiency of energy transfer from phycobilisomes to photosystems (PS). We show that growth was the most limited under blue light due to inefficient light harvesting, and that many cellular processes are tightly linked to the redox state of the plastoquinone (PQ) pool, which was the most reduced under red light. The PSI-to-PSII ratio was low under blue photons, however, it was not the main growth-limiting factor, since it was even more reduced under violet and near far-red lights, where Synechocystis grew faster compared to blue light. Our results provide insight into the spectral dependence of phototrophic growth and can provide the foundation for future studies of molecular mechanisms underlying light acclimation in cyanobacteria, leading to light optimization in controlled cultivations.
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Affiliation(s)
- Tomáš Zavřel
- Department of Adaptive Biotechnologies, Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, Brno 60300, Czechia
| | - Anna Segečová
- Department of Adaptive Biotechnologies, Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, Brno 60300, Czechia
| | - László Kovács
- Institute of Plant Biology, HUN-REN Biological Research Centre, Temesvári krt. 62, Szeged 6726, Hungary
| | - Martin Lukeš
- Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradská 237, Třeboň 379 01, Czechia
| | - Zoltán Novák
- HUN-REN Balaton Limnological Research Institute, Klebelsberg Kuno utca 3., Tihany 8237, Hungary
| | - Anne-Christin Pohland
- HUN-REN Balaton Limnological Research Institute, Klebelsberg Kuno utca 3., Tihany 8237, Hungary
| | - Milán Szabó
- Institute of Plant Biology, HUN-REN Biological Research Centre, Temesvári krt. 62, Szeged 6726, Hungary
| | - Boglárka Somogyi
- HUN-REN Balaton Limnological Research Institute, Klebelsberg Kuno utca 3., Tihany 8237, Hungary
| | - Ondřej Prášil
- Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradská 237, Třeboň 379 01, Czechia
| | - Jan Červený
- Department of Adaptive Biotechnologies, Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, Brno 60300, Czechia
| | - Gábor Bernát
- HUN-REN Balaton Limnological Research Institute, Klebelsberg Kuno utca 3., Tihany 8237, Hungary
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Osyczka P, Myśliwa-Kurdziel B. The pattern of photosynthetic response and adaptation to changing light conditions in lichens is linked to their ecological range. PHOTOSYNTHESIS RESEARCH 2023:10.1007/s11120-023-01015-z. [PMID: 36976446 DOI: 10.1007/s11120-023-01015-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 03/20/2023] [Indexed: 06/18/2023]
Abstract
Epiphytic lichens constitute an important component of biodiversity in both deforested and forest ecosystems. Widespread occurrence is the domain of generalist lichens or those that prefer open areas. While, many stenoecious lichens find shelter only in a shaded interior of forests. Light is one of the factors known to be responsible for lichen distribution. Nevertheless, the effect of light intensity on photosynthesis of lichen photobionts remain largely unknown. We investigated photosynthesis in lichens with different ecological properties in relation to light as the only parameter modified during the experiments. The aim was to find links between this parameter and habitat requirements of a given lichen. We applied the methods based on a saturating light pulse and modulated light to perform comprehensive analyses of fast and slow chlorophyll fluorescence transient (OJIP and PSMT) combined with quenching analysis. We also examined the rate of CO2 assimilation. Common or generalist lichens, i.e. Hypogymnia physodes, Flavoparmelia caperata and Parmelia sulcata, are able to adapt to a wide range of light intensity. Moreover, the latter species, which prefers open areas, dissipates the excess energy most efficiently. Conversely, Cetrelia cetrarioides considered an old-growth forest indicator, demonstrates definitely lower range of energy dissipation than other species, although it assimilates CO2 efficiently both at low and high light. We conclude that functional plasticity of the thylakoid membranes of photobionts largely determines the dispersal abilities of lichens and light intensity is one of the most important factors determining the specificity of a species to a given habitat.
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Affiliation(s)
- Piotr Osyczka
- Faculty of Biology, Institute of Botany, Jagiellonian University in Kraków, Gronostajowa 3, 30-387, Kraków, Poland
| | - Beata Myśliwa-Kurdziel
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University in Kraków, Gronostajowa 7, 30-387, Kraków, Poland.
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Li X, Liang Y, Li K, Jin P, Tang J, Klepacz-Smółka A, Ledakowicz S, Daroch M. Effects of Low Temperature, Nitrogen Starvation and Their Combination on the Photosynthesis and Metabolites of Thermosynechococcus E542: A Comparison Study. PLANTS 2021; 10:plants10102101. [PMID: 34685910 PMCID: PMC8537721 DOI: 10.3390/plants10102101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 11/25/2022]
Abstract
Both low temperature and nitrogen starvation caused chlorosis of cyanobacteria. Here, in this study, for the first time, we compared the effects of low temperature, nitrogen starvation, and their combination on the photosynthesis and metabolites of a thermophilic cyanobacterium strain, Thermosynechococcus E542. Under various culture conditions, the growth rates, pigment contents, and chlorophyll fluorescence were monitored, and the composition of alkanes, lipidomes, and carbohydrates were determined. It was found that low temperature (35 °C) significantly suppressed the growth of Thermosynechococcus E542. Nitrogen starvation at 45 °C and 55 °C did not affect the growth; however, combined treatment of low temperature and nitrogen starvation led to the lowest growth rate and biomass productivity. Both low temperature and nitrogen starvation caused significantly declined contents of pigments, but they resulted in a different effect on the OJIP curves, and their combination led to the lowest pigment contents. The composition of fatty acids and alkanes was altered upon low-temperature cultivation, while nitrogen starvation caused reduced contents of all lipids. The low temperature did not affect carbohydrate contents, while nitrogen starvation greatly enhanced carbohydrate content, and their combination did not enhance carbohydrate content, but led to reduced productivity. These results revealed the influence of low temperature, nitrogen starvation, and their combined treatment for the accumulation of phycobiliproteins, lipids, and carbohydrates of a thermophilic cyanobacterium strain, Thermosynechococcus E542.
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Affiliation(s)
- Xingkang Li
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
- Department School of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China
| | - Yuanmei Liang
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
| | - Kai Li
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
| | - Peng Jin
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
| | - Jie Tang
- School of Food and Bioengineering, Chengdu University, Chengdu 610106, China;
| | - Anna Klepacz-Smółka
- Department of Bioprocess Engineering, Faculty of Process and Environmental Engineering, Lodz University of Technology, ul. Wolczanska 213, 90-924 Lodz, Poland; (A.K.-S.); (S.L.)
| | - Stanislaw Ledakowicz
- Department of Bioprocess Engineering, Faculty of Process and Environmental Engineering, Lodz University of Technology, ul. Wolczanska 213, 90-924 Lodz, Poland; (A.K.-S.); (S.L.)
| | - Maurycy Daroch
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; (X.L.); (Y.L.); (K.L.); (P.J.)
- Correspondence: ; Tel.: +86-0755-26032184
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Schreiber U, Klughammer C. Evidence for variable chlorophyll fluorescence of photosystem I in vivo. PHOTOSYNTHESIS RESEARCH 2021; 149:213-231. [PMID: 33464442 PMCID: PMC8382641 DOI: 10.1007/s11120-020-00814-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/16/2020] [Indexed: 05/09/2023]
Abstract
Room temperature fluorescence in vivo and its light-induced changes are dominated by chlorophyll a fluorescence excited in photosystem II, F(II), peaking around 685 nm. Photosystem I fluorescence, F(I), peaking around 730 nm, so far has been assumed to be constant in vivo. Here, we present evidence for significant contributions of F(I) to variable fluorescence in the green unicellular alga Chlorella vulgaris, the cyanobacterium Synechococcus leopoliensis and a light-green ivy leaf. A Multi-Color-PAM fluorometer was applied for measurements of the polyphasic fluorescence rise (O-I1-I2-P) induced by strong 440 nm light in a dilute suspension of Chlorella, with detection alternating between emission above 700 nm (F > 700) and below 710 nm (F < 710). By averaging 10 curves each of the F > 700 and F < 710 recordings even small differences could be reliably evaluated. After equalizing the amplitudes of the O-I1 phase, which constitutes a specific F(II) response, the O-I1-I2 parts of the two recordings were close to identical, whereas the I2-P phase was larger in F > 700 than in F < 710 by a factor of 1.42. In analogous measurements with Synechococcus carried out in the dark state 2 using strong 625 nm actinic light, after O-I1 equalization the I2-P phase in F > 700 exceeded that in F < 710 even by a factor of 1.99. In measurements with Chlorella, the I2-P phase and with it the apparent variable fluorescence of PS I, Fv(I), were suppressed by moderate actinic background light and by the plastoquinone antagonist DBMIB. Analogous measurements with leaves are rendered problematic by unavoidable light intensity gradients and the resulting heterogenic origins of F > 700 and F < 710. However, a light-green young ivy leaf gave qualitatively similar results as those obtained with the suspensions, thus strongly suggesting the existence of Fv(I) also in leaves.
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Affiliation(s)
- Ulrich Schreiber
- Julius-Von-Sachs Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs Platz 2, 97082, Würzburg, Germany.
| | - Christof Klughammer
- Julius-Von-Sachs Institut für Biowissenschaften, Universität Würzburg, Julius-von-Sachs Platz 2, 97082, Würzburg, Germany
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Barták M, Hájek J, Orekhova A, Villagra J, Marín C, Palfner G, Casanova-Katny A. Inhibition of Primary Photosynthesis in Desiccating Antarctic Lichens Differing in Their Photobionts, Thallus Morphology, and Spectral Properties. Microorganisms 2021; 9:microorganisms9040818. [PMID: 33924436 PMCID: PMC8070113 DOI: 10.3390/microorganisms9040818] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/02/2021] [Accepted: 04/07/2021] [Indexed: 11/16/2022] Open
Abstract
Five macrolichens of different thallus morphology from Antarctica (King George Island) were used for this ecophysiological study. The effect of thallus desiccation on primary photosynthetic processes was examined. We investigated the lichens' responses to the relative water content (RWC) in their thalli during the transition from a wet (RWC of 100%) to a dry state (RWC of 0%). The slow Kautsky kinetics of chlorophyll fluorescence (ChlF) that was recorded during controlled dehydration (RWC decreased from 100 to 0%) and supplemented with a quenching analysis revealed a polyphasic species-specific response of variable fluorescence. The changes in ChlF at a steady state (Fs), potential and effective quantum yields of photosystem II (FV/FM, ΦPSII), and nonphotochemical quenching (NPQ) reflected a desiccation-induced inhibition of the photosynthetic processes. The dehydration-dependent fall in FV/FM and ΦPSII was species-specific, starting at an RWC range of 22-32%. The critical RWC for ΦPSII was below 5%. The changes indicated the involvement of protective mechanisms in the chloroplastic apparatus of lichen photobionts at RWCs of below 20%. In both the wet and dry states, the spectral reflectance curves (SRC) (wavelength 400-800 nm) and indices (NDVI, PRI) of the studied lichen species were measured. Black Himantormia lugubris showed no difference in the SRCs between wet and dry state. Other lichens showed a higher reflectance in the dry state compared to the wet state. The lichen morphology and anatomy data, together with the ChlF and spectral reflectance data, are discussed in relation to its potential for ecophysiological studies in Antarctic lichens.
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Affiliation(s)
- Miloš Barták
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, Building A13/119, 625 00 Brno, Czech Republic; (M.B.); (J.H.); (A.O.)
| | - Josef Hájek
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, Building A13/119, 625 00 Brno, Czech Republic; (M.B.); (J.H.); (A.O.)
| | - Alla Orekhova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, Building A13/119, 625 00 Brno, Czech Republic; (M.B.); (J.H.); (A.O.)
| | - Johana Villagra
- Laboratory of Plant Ecophysiology, Faculty of Natural Resources, Campus Luis Rivas del Canto, Catholic University of Temuco, Rudecindo Ortega #03694, 4780000 Temuco, Chile;
| | - Catalina Marín
- Laboratory of Mycology and Mycorrhiza, Faculty of Natural Sciences and Oceanography, Campus Concepción, Concepción University, 4030000 Concepción, Chile; (C.M.); (G.P.)
| | - Götz Palfner
- Laboratory of Mycology and Mycorrhiza, Faculty of Natural Sciences and Oceanography, Campus Concepción, Concepción University, 4030000 Concepción, Chile; (C.M.); (G.P.)
| | - Angélica Casanova-Katny
- Laboratory of Plant Ecophysiology, Faculty of Natural Resources, Campus Luis Rivas del Canto, Catholic University of Temuco, Rudecindo Ortega #03694, 4780000 Temuco, Chile;
- Correspondence: ; Tel.: +56-96-209-7709
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Forsman JA, Eaton-Rye JJ. The Interaction between PsbT and the DE Loop of D1 in Photosystem II Stabilizes the Quinone-Iron Electron Acceptor Complex. Biochemistry 2020; 60:53-63. [PMID: 33332101 DOI: 10.1021/acs.biochem.0c00668] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The X-ray-derived Photosystem II (PS II) structure from the thermophilic cyanobacterium Thermosynechococcus vulcanus (Protein Data Bank entry 4UB6) indicates Phe239 of the DE loop of the D1 protein forms a hydrophobic interaction with Pro27 and Ile29 at the C-terminus of the 5 kDa PsbT protein found at the monomer-monomer interface of the PS II dimer. To investigate the importance of this interaction, we created the F239A and F239L mutants in Synechocystis sp. PCC 6803 through targeted mutagenesis of the D1:Phe239 residue into either an alanine or a leucine. Under moderate-light conditions, the F239A strain displayed reduced rates of oxygen evolution and impaired rates of fluorescence decay following a single-turnover actinic flash, while the F239L strain behaved like the control; however, under high-light conditions, the F239A and F239L strains grew more slowly than the control. Our results indicate the quinone-iron acceptor complex becomes more accessible to exogenously added electron acceptors in the F239A mutant and a ΔPsbT strain when compared with the control and F239L strains. This led to the hypothesis that the interaction between D1:Phe239 and the PsbT subunit is required to restrict movement of the DE loop of the D1 subunit, and we suggest disruption of this interaction may perturb the binding of bicarbonate to the non-heme iron and contribute to the signal for PS II to undergo repair following photodamage.
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Affiliation(s)
- Jack A Forsman
- Department of Biochemistry, University of Otago, Dunedin 9016, New Zealand
| | - Julian J Eaton-Rye
- Department of Biochemistry, University of Otago, Dunedin 9016, New Zealand
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Belyaeva NE, Bulychev AA, Klementiev KE, Paschenko VZ, Riznichenko GY, Rubin AB. Model quantification of the light-induced thylakoid membrane processes in Synechocystis sp. PCC 6803 in vivo and after exposure to radioactive irradiation. PHOTOSYNTHESIS RESEARCH 2020; 146:259-278. [PMID: 32734447 DOI: 10.1007/s11120-020-00774-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Measurements of OJIP-SMT patterns of fluorescence induction (FI) in Synechocystis sp. PCC 6803 (Synechocystis) cells on a time scale up to several minutes were mathematically treated within the framework of thylakoid membrane (T-M) model (Belyaeva et al., Photosynth Res 140:1-19, 2019) that was renewed to account for the state transitions effects. Principles of describing electron transfer in reaction centers of photosystems II and I (PSII and PSI) and cytochrome b6f complex remained unchanged, whereas parameters for dissipative reactions of non-radiative charge recombination were altered depending on the oxidation state of QB-site (neutral, reduced by one electron, empty, reduced by two electrons). According to our calculations, the initial content of plastoquinol (PQH2) in the total quinone pool of Synechocystis cells adapted to darkness for 10 min ranged between 20 and 40%. The results imply that the PQ pool mediates photosynthetic and respiratory charge flows. The redistribution of PBS antenna units responsible for the increase of Chl fluorescence in cyanobacteria (qT2 → 1) upon state 2 → 1 transition or the fluorescence lowering (qT1 → 2) due to state 1 → 2 transition were described in the model by exponential functions. Parameters of dynamically changed effective cross section were found by means of simulations of OJIP-SMT patterns observed on Synechocystis cells upon strong (3000 μmol photons m-2s-1) and moderate (1000 μmol photons m-2s-1) actinic light intensities. The corresponding light constant values kLΣAnt = 1.2 ms-1 and 0.4 ms-1 define the excitation of total antenna pool dynamically redistributed between PSII and PSI reaction centers. Although the OCP-induced quenching of antenna excitation is not involved in the model, the main features of the induction signals have been satisfactorily explained. In the case of strong illumination, the effective cross section decreases by approximately 33% for irradiated Synechocystis cells as compared to untreated cells. Under moderate light, the irradiated Synechocystis cells showed in simulations the same cross section as the untreated cells. The thylakoid model renewed with state transitions description allowed simulation of fluorescence induction OJIP-SMT curves detected on time scale from microseconds to minutes.
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Affiliation(s)
- N E Belyaeva
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov Moscow State University, 119234, Moscow, Russia.
| | - A A Bulychev
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov Moscow State University, 119234, Moscow, Russia
| | - K E Klementiev
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov Moscow State University, 119234, Moscow, Russia
| | - V Z Paschenko
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov Moscow State University, 119234, Moscow, Russia
| | - G Yu Riznichenko
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov Moscow State University, 119234, Moscow, Russia
| | - A B Rubin
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov Moscow State University, 119234, Moscow, Russia
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Deficiency in flavodiiron protein Flv3 promotes cyclic electron flow and state transition under high light in the cyanobacterium Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148318. [PMID: 32979345 DOI: 10.1016/j.bbabio.2020.148318] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 09/11/2020] [Accepted: 09/19/2020] [Indexed: 11/21/2022]
Abstract
Photosynthetic organisms adjust their activity to changes in irradiance by different ways, including the operation of cyclic electron flow around photosystem I (PSI) and state transitions that redistribute amounts of light energy absorbed by PSI and PSII. In dark-acclimated wild type cells of Synechocystis PCC 6803, linear electron transport was activated after the first 500 ms of illumination, while cyclic electron flow around PSI was long predominant in the mutant deficient in flavodiiron protein Flv3. Chlorophyll P700 oxidation associated with activation of linear electron flow extended in the Flv3- mutant to several tens of seconds and included a P700+ re-reduction phase. Parallel monitoring of chlorophyll fluorescence and the redox state of P700 indicated that, at low light intensity both in wild type and in the Flv3- mutant, the transient re-reduction step coincided in time with S-M fluorescence rise, which reflected state 2-state 1 transition (Kaňa et al., 2012). Despite variations in the initial redox state of plastoquinone pool, the oxidases-deficient mutant, succinate dehydrogenase-deficient mutant, and wild type cells did not show the S-M rise under high-intensity light until additional Flv3- mutation was introduced in these strains. Thus, the lack of available electron acceptor for PSI was the main cause for the appearance of S-M fluorescence rise under high light. It is concluded that the lack of Flv3 protein promotes cyclic electron flow around PSI and facilitates the subsequent state 2-state 1 transition in the absence of strict relation to the dark-operated pathways of plastoquinone reduction or oxidation.
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Tan X, Dai K, Parajuli K, Hang X, Duan Z, Hu Y. Effects of Phenolic Pollution on Interspecific Competition between Microcystis aeruginosa and Chlorella pyrenoidosa and their Photosynthetic Responses. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16203947. [PMID: 31627270 PMCID: PMC6843285 DOI: 10.3390/ijerph16203947] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/23/2019] [Accepted: 09/30/2019] [Indexed: 11/18/2022]
Abstract
The demand for phenolic compounds has been increasing rapidly, which has intensified the production and usage of phenol at a commercial scale. In some polluted water bodies, phenol has become one of the typical aromatic contaminants. Such water bodies are inescapably influenced by nutrients from human activities, and also suffer from nuisance cyanobacterial blooms. While phenolic pollution threatens water safety and ecological balance, algal cells are ubiquitous and sensitive to pollutants. Therefore, effects of phenolic pollution on interspecific competition between a bloom-forming cyanobacterium and other common alga merit quantitative investigation. In this study, the effects of phenol on Microcystis aeruginosa (M. aeruginosa, a bloom-forming cyanobacterium) and Chlorella pyrenoidosa (C. pyrenoidosa, a ubiquitous green alga) were analyzed in mono- and co-cultures. The two species were exposed to a series of phenol treatments (0, 2, 20, and 200 μg mL−1). Population dynamics were measured by a flow cytometer and analyzed by the Lotka-Volterra model. The results showed that M. aeruginosa was more sensitive to phenol (EC50 = 80.8 ± 0.16 μg mL−1) compared to C. pyrenoidosa (EC50 = 631.4 ± 0.41 μg mL−1) in mono-cultures. M. aeruginosa won in the co-cultures when phenol was below or equal to 20 μg mL−1, while C. pyrenoidosa became the dominant species in the 200 μg mL−1 treatment. Photosynthetic activity was measured by a fluometer. Results showed phenol significantly impacted the photosynthetic activity of M. aeruginosa by inhibiting the acceptor side of its photosystem II (PSII), while such inhibition in C. pyrenoidosa was only observed in the highest phenol treatment (200 μg mL−1). This study provides a better understanding for predicting the succession of algal community structure in water bodies susceptible to phenolic contamination. Moreover, it reveals the mechanism on photosynthetic responses of these two species under phenolic stress.
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Affiliation(s)
- Xiao Tan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
| | - Kaiwen Dai
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
| | - Keshab Parajuli
- School of Population and Global Health, Faculty of Medicine, Denistry and Health Sciences, The University of Melbourne, VIC 3010 Melbourne, Australia.
| | - Xiaoshuai Hang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China.
| | - Zhipeng Duan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
| | - Yue Hu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
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Belyaeva NE, Bulychev AA, Riznichenko GY, Rubin AB. Analyzing both the fast and the slow phases of chlorophyll a fluorescence and P700 absorbance changes in dark-adapted and preilluminated pea leaves using a Thylakoid Membrane model. PHOTOSYNTHESIS RESEARCH 2019; 140:1-19. [PMID: 30810971 DOI: 10.1007/s11120-019-00627-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 02/12/2019] [Indexed: 05/25/2023]
Abstract
The dark-to-light transitions enable energization of the thylakoid membrane (TM), which is reflected in fast and slow (OJIPSMT or OABCDE) stages of fluorescence induction (FI) and P700 oxidoreduction changes (ΔA810). A Thylakoid Membrane model (T-M model), in which special emphasis has been placed on ferredoxin-NADP+-oxidoreductase (FNR) activation and energy-dependent qE quenching, was applied for quantifying the kinetics of FI and ΔA810. Pea leaves were kept in darkness for 15 min and then the FI and ΔA810 signals were measured upon actinic illumination, applied either directly or after a 10-s light pulse coupled with a subsequent 10-s dark interval. On the time scale from 40 µs to 30 s, the parallel T-M model fittings to both FI and ΔA810 signals were obtained. The parameters of FNR activation and the buildup of qE quenching were found to differ for dark-adapted and preilluminated leaves. At the onset of actinic light, photosystem II (PSII) acceptors were oxidized (neutral) after dark adaptation, while the redox states with closed and/or semiquinone QA(-)QB(-) forms were supposedly generated after preillumination, and did not relax within the 10 s dark interval. In qE simulations, a pH-dependent Hill relationship was used. The rate constant of heat losses in PSII antenna kD(t) was found to increase from the basic value kDconst, at the onset of illumination, to its maximal level kDvar due to lumenal acidification. In dark-adapted leaves, a low value of kDconst of ∼ 2 × 106 s-1 was found. Simulations on the microsecond to 30 s time scale revealed that the slow P-S-M-T phases of the fluorescence induction were sensitive to light-induced FNR activation and high-energy qE quenching. Thus, the corresponding time-dependent rate constants kD(t) and kFNR(t) change substantially upon the release of electron transport on the acceptor side of PSI and during the NPQ development. The transitions between the cyclic and linear electron transport modes have also been quantified in this paper.
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Affiliation(s)
- N E Belyaeva
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov, Moscow State University, Moscow, Russia, 119234.
| | - A A Bulychev
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov, Moscow State University, Moscow, Russia, 119234
| | - G Yu Riznichenko
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov, Moscow State University, Moscow, Russia, 119234
| | - A B Rubin
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov, Moscow State University, Moscow, Russia, 119234
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11
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Allakhverdiev SI, Tomo T, Stamatakis K. International conference on "Photosynthesis research for sustainability-2015" in honor of George C. Papageorgiou", September 21-26, 2015, Crete, Greece. PHOTOSYNTHESIS RESEARCH 2016; 130:1-10. [PMID: 26650229 DOI: 10.1007/s11120-015-0207-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
During September 21-26, 2015, an international conference entitled ''Photosynthesis Research for Sustainability-2015'' was held in honor of George C. Papageorgiou at the Conference Center of the Orthodox Academy of Crete, an exceptionally beautiful location right on the Mediterranean Sea coast, Kolymvari, Chania, Crete, (Greece) (see http://photosynthesis2015.cellreg.org/ ). The meeting was held under the auspices of the Greek "General Secretariat for Research and Technology" (GSRT). We first provide a brief introduction and key contributions of George C. Papageorgiou, the honored scientist, and then information on the conference, on the speakers, and the program. A special feature of this conference was awards given to 13 young investigators, who are recognized in this Report. Several photographs are also included; they show the pleasant ambience at this conference. We invite the readers to the next conference on "Photosynthesis Research for Sustainability-2016," which will honor Nathan Nelson and T. Nejat Veziroglu; it will be held during June 19-25, 2016, in Pushchino, Moscow Region, Russia (see http://photosynthesis2016.cellreg.org/ ).
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Affiliation(s)
- Suleyman I Allakhverdiev
- Controlled Photobiosynthesis Laboratory, Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, Russia, 127276
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region, Russia, 142290
- Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Leninskie Gory 1-12, Moscow, Russia, 119991
| | - Tatsuya Tomo
- Department of Biology, Faculty of Science, Tokyo University of Science, Kagurazaka 1-3, Shinjuku-Ku, Tokyo, 162-8601, Japan
- PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama, 332-0012, Japan
| | - Kostas Stamatakis
- Institute of Biosciences and Applications, National Center of Scientific Research "Demokritos", 153 10, Athens, Greece
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Stamatakis K, Papageorgiou GC. Effects of exogenous β-carotene, a chemical scavenger of singlet oxygen, on the millisecond rise of chlorophyll a fluorescence of cyanobacterium Synechococcus sp. PCC 7942. PHOTOSYNTHESIS RESEARCH 2016; 130:317-324. [PMID: 27034066 DOI: 10.1007/s11120-016-0255-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 03/23/2016] [Indexed: 06/05/2023]
Abstract
Singlet-excited oxygen (1O 2* ) has been recognized as the most destructive member of the reactive oxygen species (ROS) which are formed during oxygenic photosynthesis by plants, algae, and cyanobacteria. ROS and 1O 2* are known to damage protein and phospholipid structures and to impair photosynthetic electron transport and de novo protein synthesis. Partial protection is afforded to photosynthetic organism by the β-carotene (β-Car) molecules which accompany chlorophyll (Chl) a in the pigment-protein complexes of Photosystem II (PS II). In this paper, we studied the effects of exogenously added β-Car on the initial kinetic rise of Chl a fluorescence (10-1000 μs, the OJ segment) from the unicellular cyanobacterium Synechococcus sp. PCC7942. We show that the added β-Car enhances Chl a fluorescence when it is excited at an intensity of 3000 μmol photons m-2 s-1 but not when excited at 1000 μmol photons m-2 s-1. Since β-Car is an efficient scavenger of 1O 2* , as well as a quencher of 3Chl a * (precursor of 1O 2* ), both of which are more abundant at higher excitations, we assume that the higher Chl a fluorescence in its presence signifies a protective effect against photo-oxidative damages of Chl proteins. The protective effect of added β-Car is not observed in O2-depleted cell suspensions. Lastly, in contrast to β-Car, a water-insoluble molecule, a water-soluble scavenger of 1O 2* , histidine, provides no protection to Chl proteins during the same time period (10-1000 μs).
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Affiliation(s)
- Kostas Stamatakis
- Institute of Biosciences and Applications, National Center of Scientific Research "Demokritos", 15310, Athens, Greece
| | - George C Papageorgiou
- Institute of Biosciences and Applications, National Center of Scientific Research "Demokritos", 15310, Athens, Greece.
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13
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Abramson BW, Kachel B, Kramer DM, Ducat DC. Increased Photochemical Efficiency in Cyanobacteria via an Engineered Sucrose Sink. PLANT & CELL PHYSIOLOGY 2016; 57:2451-2460. [PMID: 27742883 DOI: 10.1093/pcp/pcw169] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/25/2016] [Indexed: 06/06/2023]
Abstract
In plants, a limited capacity to utilize or export the end-products of the Calvin-Benson cycle (CB) from photosynthetically active source cells to non-photosynthetic sink cells can result in reduced carbon capture and photosynthetic electron transport (PET), and lowered photochemical efficiency. The down-regulation of photosynthesis caused by reduced capacity to utilize photosynthate has been termed 'sink limitation'. Recently, several cyanobacterial and algal strains engineered to overproduce target metabolites have exhibited increased photochemistry, suggesting that possible source-sink regulatory mechanisms may be involved. We directly examined photochemical properties following induction of a heterologous sucrose 'sink' in the unicellular cyanobacterium Synechococcus elongatus PCC 7942. We show that total photochemistry increases proportionally to the experimentally controlled rate of sucrose export. Importantly, the quantum yield of PSII (ΦII) increases in response to sucrose export while the PET chain becomes more oxidized from less PSI acceptor-side limitation, suggesting increased CB activity and a decrease in sink limitation. Enhanced photosynthetic activity and linear electron flow are detectable within hours of induction of the heterologous sink and are independent of pigmentation alterations or the ionic/osmotic effects of the induction system. These observations provide direct evidence that secretion of heterologous carbon bioproducts can be used as an alternative approach to improve photosynthetic efficiency, presumably by by-passing sink limitation. Our results also suggest that engineered microalgal production strains are valuable alternative models for examining photosynthetic sink limitation because they enable greater control and monitoring of metabolite fluxes relative to plants.
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Affiliation(s)
- Bradley W Abramson
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Cell and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Benjamin Kachel
- Department of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Daniel C Ducat
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
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Stirbet A. The slow phase of chlorophyll a fluorescence induction in silico: Origin of the S-M fluorescence rise. PHOTOSYNTHESIS RESEARCH 2016; 130:193-213. [PMID: 26995191 DOI: 10.1007/s11120-016-0243-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/04/2016] [Indexed: 06/05/2023]
Abstract
In higher plants, algae, and cyanobacteria, chlorophyll (Chl) a fluorescence induction (ChlFI) has a fast (under a second) increasing OJIP phase and a slow (few minutes) PS(M)T phase, where O is for origin, the minimum fluorescence, J and I for intermediate levels, P for peak, S for a semi-steady state, M for a maximum (which is sometimes missing), and T for the terminal steady-state level. We have used a photosynthesis model of Ebenhöh et al. (Philos Trans R Soc B, 2014, doi: 10.1098/rstb.2013.0223 ) in an attempt to simulate the slow PS(M)T phase and to determine the origin of the S-M rise in Chlamydomonas (C.) reinhardtii cells. Our experiments in silico show that a slow fluorescence S-M rise (as that observed, e.g., by Kodru et al. (Photosynth Res 125:219-231, 2015) can be simulated only if the photosynthetic samples are initially in a so-called "state 2," when the absorption cross section (CS) of Photosystem II (PSII) is lower than that of PSI, and Chl a fluorescence is low (see, e.g., a review by Papageorgiou and Govindjee (J Photochem Photobiol B 104:258-270, 2011). In this case, simulations show that illumination induces a state 2 (s2) to state 1 (s1) transition (qT21), and a slow S-M rise in the simulated ChlFI curve, since the fluorescence yield is known to be higher in s1, when CS of PSII is larger than that of PSI. Additionally, we have analyzed how light intensity and several photosynthetic processes influence the degree of this qT21, and thus the relative amplitude of the simulated S-M phase. A refinement of the photosynthesis model is, however, necessary in order to obtain a better fit of the simulation data with the measured ChlFI curves.
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15
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Bolychevtseva YV, Kuzminov FI, Elanskaya IV, Gorbunov MY, Karapetyan NV. Photosystem activity and state transitions of the photosynthetic apparatus in cyanobacterium Synechocystis PCC 6803 mutants with different redox state of the plastoquinone pool. BIOCHEMISTRY (MOSCOW) 2015; 80:50-60. [PMID: 25754039 DOI: 10.1134/s000629791501006x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To better understand how photosystem (PS) activity is regulated during state transitions in cyanobacteria, we studied photosynthetic parameters of photosystem II (PSII) and photosystem I (PSI) in Synechocystis PCC 6803 wild type (WT) and its mutants deficient in oxidases (Ox(-)) or succinate dehydrogenase (SDH(-)). Dark-adapted Ox(-) mutant, lacking the oxidation agents, is expected to have a reduced PQ pool, while in SDH(-) mutant the PQ pool after dark adaptation will be more oxidized due to partial inhibition of the respiratory chain electron carriers. In this work, we tested the hypothesis that control of balance between linear and cyclic electron transport by the redox state of the PQ pool will affect PSII photosynthetic activity during state transition. We found that the PQ pool was reduced in Ox(-) mutant, but oxidized in SDH(-) mutant after prolonged dark adaptation, indicating different states of the photosynthetic apparatus in these mutants. Analysis of variable fluorescence and 77K fluorescence spectra revealed that the WT and SDH(-) mutant were in State 1 after dark adaptation, while the Ox(-) mutant was in State 2. State 2 was characterized by ~1.5 time lower photochemical activity of PSII, as well as high rate of P700 reduction and the low level of P700 oxidation, indicating high activity of cyclic electron transfer around PSI. Illumination with continuous light 1 (440 nm) along with flashes of light 2 (620 nm) allowed oxidation of the PQ pool in the Ox(-) mutant, thus promoting it to State 1, but it did not affect PSII activity in dark adapted WT and SDH(-) mutant. State 1 in the Ox(-) mutant was characterized by high variable fluorescence and P700(+) levels typical for WT and the SDH(-) mutant, indicating acceleration of linear electron transport. Thus, we show that PSII of cyanobacteria has a higher photosynthetic activity in State 1, while it is partially inactivated in State 2. This process is controlled by the redox state of PQ in cyanobacteria through enhancement/inhibition of electron transport on the acceptor side of PSII.
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Affiliation(s)
- Y V Bolychevtseva
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
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16
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Kodru S, Malavath T, Devadasu E, Nellaepalli S, Stirbet A, Subramanyam R. The slow S to M rise of chlorophyll a fluorescence reflects transition from state 2 to state 1 in the green alga Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2015; 125:219-31. [PMID: 25663564 DOI: 10.1007/s11120-015-0084-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 01/08/2015] [Indexed: 05/03/2023]
Abstract
The green alga Chlamydomonas (C.) reinhardtii is a model organism for photosynthesis research. State transitions regulate redistribution of excitation energy between photosystem I (PS I) and photosystem II (PS II) to provide balanced photosynthesis. Chlorophyll (Chl) a fluorescence induction (the so-called OJIPSMT transient) is a signature of several photosynthetic reactions. Here, we show that the slow (seconds to minutes) S to M fluorescence rise is reduced or absent in the stt7 mutant (which is locked in state 1) in C. reinhardtii. This suggests that the SM rise in wild type C. reinhardtii may be due to state 2 (low fluorescence state; larger antenna in PS I) to state 1 (high fluorescence state; larger antenna in PS II) transition, and thus, it can be used as an efficient and quick method to monitor state transitions in algae, as has already been shown in cyanobacteria (Papageorgiou et al. 1999, 2007; Kaňa et al. 2012). We also discuss our results on the effects of (1) 3-(3,4-dichlorophenyl)-1,4-dimethyl urea, an inhibitor of electron transport; (2) n-propyl gallate, an inhibitor of alternative oxidase (AOX) in mitochondria and of plastid terminal oxidase in chloroplasts; (3) salicylhydroxamic acid, an inhibitor of AOX in mitochondria; and (4) carbonyl cyanide p-trifluoromethoxyphenylhydrazone, an uncoupler of phosphorylation, which dissipates proton gradient across membranes. Based on the data presented in this paper, we conclude that the slow PSMT fluorescence transient in C. reinhardtii is due to the superimposition of, at least, two phenomena: qE dependent non-photochemical quenching of the excited state of Chl, and state transitions.
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Affiliation(s)
- Sireesha Kodru
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500 046, India
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17
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Stirbet A, Riznichenko GY, Rubin AB, Govindjee. Modeling chlorophyll a fluorescence transient: relation to photosynthesis. BIOCHEMISTRY (MOSCOW) 2015; 79:291-323. [PMID: 24910205 DOI: 10.1134/s0006297914040014] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To honor Academician Alexander Abramovitch Krasnovsky, we present here an educational review on the relation of chlorophyll a fluorescence transient to various processes in photosynthesis. The initial event in oxygenic photosynthesis is light absorption by chlorophylls (Chls), carotenoids, and, in some cases, phycobilins; these pigments form the antenna. Most of the energy is transferred to reaction centers where it is used for charge separation. The small part of energy that is not used in photochemistry is dissipated as heat or re-emitted as fluorescence. When a photosynthetic sample is transferred from dark to light, Chl a fluorescence (ChlF) intensity shows characteristic changes in time called fluorescence transient, the OJIPSMT transient, where O (the origin) is for the first measured minimum fluorescence level; J and I for intermediate inflections; P for peak; S for semi-steady state level; M for maximum; and T for terminal steady state level. This transient is a real signature of photosynthesis, since diverse events can be related to it, such as: changes in redox states of components of the linear electron transport flow, involvement of alternative electron routes, the build-up of a transmembrane pH gradient and membrane potential, activation of different nonphotochemical quenching processes, activation of the Calvin-Benson cycle, and other processes. In this review, we present our views on how different segments of the OJIPSMT transient are influenced by various photosynthetic processes, and discuss a number of studies involving mathematical modeling and simulation of the ChlF transient. A special emphasis is given to the slower PSMT phase, for which many studies have been recently published, but they are less known than on the faster OJIP phase.
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Affiliation(s)
- A Stirbet
- 204 Anne Burras Lane, Newport News, VA 23606, USA.
| | | | | | - Govindjee
- Department of Plant Biology, Department of Biochemistry and Center of Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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18
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Stamatakis K, Tsimilli-Michael M, Papageorgiou GC. On the question of the light-harvesting role of β-carotene in photosystem II and photosystem I core complexes. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 81:121-7. [PMID: 24529497 DOI: 10.1016/j.plaphy.2014.01.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 01/22/2014] [Indexed: 05/24/2023]
Abstract
β-Carotene is the only carotenoid present in the core complexes of Photosystems I and II. Its proximity to chlorophyll a molecules enables intermolecular electronic interactions, including β-carotene to chlorophyll a electronic excitation transfers. However, it has been well documented that, compared to chlorophylls and to phycobilins, the light harvesting efficiency of β-carotenes for photosynthetic O2 evolution is poor. This is more evident in cyanobacteria than in plants and algae because they lack accessory light harvesting pigments with absorptions that overlap the β-carotene absorption. In the present work we investigated the light harvesting role of β-carotenes in the cyanobacterium Synechococcus sp. PCC 7942 using selective β-carotene excitation and selective Photosystem detection of photo-induced electron transport to and from the intersystem plastoquinones (the plastoquinone pool). We report that, although selectively excited β-carotenes transfer electronic excitation to the chlorophyll a of both photosystems, they enable only the oxidation of the plastoquinone pool by Photosystem I but not its reduction by Photosystem II. This may suggest a light harvesting role for the β-carotenes of the Photosystem I core complex but not for those of the Photosystem II core complex. According to the present investigation, performed with whole cyanobacterial cells, the lower photosynthesis yields measured with β-Car-absorbed light can be attributed to the different excitation trapping efficiencies in the reaction centers of PSI and PSII.
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Affiliation(s)
- Kostas Stamatakis
- Institute of Biosciences and Applications, National Center for Scentific Research Demokritos, Aghia Paraskevi, Attikis 15310, Greece.
| | | | - George C Papageorgiou
- Institute of Biosciences and Applications, National Center for Scentific Research Demokritos, Aghia Paraskevi, Attikis 15310, Greece
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Stamatakis K, Papageorgiou GC. ΔpH-dependent non-photochemical quenching (qE) of excited chlorophylls in the photosystem II core complex of the freshwater cyanobacterium Synechococcus sp PCC 7942. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 81:184-189. [PMID: 24793104 DOI: 10.1016/j.plaphy.2014.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 04/08/2014] [Indexed: 06/03/2023]
Abstract
Light-induced and lumen acidity-dependent quenching (qE) of excited chlorophylls (Chl) in vivo has been amply documented in plants and algae, but not in cyanobacteria, using primarily the saturation pulse method of quenching analysis which is applied to continuously illuminated samples. This method is unsuitable for cyanobacteria because the background illumination elicits in them a very large Chl a fluorescence signal, due to a state 2 to state 1 transition, which masks fluorescence changes due to other causes. We investigated the qE problem in the cyanobacterium Synechococcus sp. PCC 7942 using a kinetic method (Chl a fluorescence induction) with which qE can be examined before the onset of the state 2 to state 1 transition and the attendant rise of Chl a fluorescence. Our results confirm the existence of a qE mechanism that operates on excited Chls a in Photosystem II core complexes of cyanobacteria.
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Affiliation(s)
- Kostas Stamatakis
- Institute of Biosciences and Applications, National Center for Scientific Research Demokritos, Aghia Paraskevi Attikis 15310, Greece.
| | - George C Papageorgiou
- Institute of Biosciences and Applications, National Center for Scientific Research Demokritos, Aghia Paraskevi Attikis 15310, Greece
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Bernát G, Schreiber U, Sendtko E, Stadnichuk IN, Rexroth S, Rögner M, Koenig F. Unique properties vs. common themes: the atypical cyanobacterium Gloeobacter violaceus PCC 7421 is capable of state transitions and blue-light-induced fluorescence quenching. PLANT & CELL PHYSIOLOGY 2012; 53:528-542. [PMID: 22302714 DOI: 10.1093/pcp/pcs009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The atypical unicellular cyanobacterium Gloeobacter violaceus PCC 7421, which diverged very early during the evolution of cyanobacteria, can be regarded as a key organism for understanding many structural, functional, regulatory and evolutionary aspects of oxygenic photosynthesis. In the present work, the performance of two basic photosynthetic adaptation/protection mechanisms, common to all other oxygenic photoautrophs, had been challenged in this ancient cyanobacterium which lacks thylakoid membranes: state transitions and non-photochemical fluorescence quenching. Both low temperature fluorescence spectra and room temperature fluorescence transients show that G. violaceus is capable of performing state transitions similar to evolutionarily more recent cyanobacteria, being in state 2 in darkness and in state 1 upon illumination by weak blue or far-red light. Compared with state 2, variable fluorescence yield in state 1 is strongly enhanced (almost 80%), while the functional absorption cross-section of PSII is only increased by 8%. In contrast to weak blue light, which enhances fluorescence yield via state 1 formation, strong blue light reversibly quenches Chl fluorescence in G. violaceus. This strongly suggests regulated heat dissipation which is triggered by the orange carotenoid protein whose presence was directly proven by immunoblotting and mass spectrometry in this primordial cyanobacterium. The results are discussed in the framework of cyanobacterial evolution.
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Affiliation(s)
- Gábor Bernát
- Plant Biochemistry, Ruhr-University Bochum, D-44801 Bochum, Germany.
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Kaňa R, Kotabová E, Komárek O, Sedivá B, Papageorgiou GC, Govindjee, Prášil O. The slow S to M fluorescence rise in cyanobacteria is due to a state 2 to state 1 transition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1237-47. [PMID: 22402228 DOI: 10.1016/j.bbabio.2012.02.024] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 02/13/2012] [Accepted: 02/20/2012] [Indexed: 11/17/2022]
Abstract
In dark-adapted plants and algae, chlorophyll a fluorescence induction peaks within 1s after irradiation due to well documented photochemical and non-photochemical processes. Here we show that the much slower fluorescence rise in cyanobacteria (the so-called "S to M rise" in tens of seconds) is due to state 2 to state 1 transition. This has been demonstrated in particular for Synechocystis PCC6803, using its RpaC(-) mutant (locked in state 1) and its wild-type cells kept in hyperosmotic suspension (locked in state 2). In both cases, the inhibition of state changes correlates with the disappearance of the S to M fluorescence rise, confirming its assignment to the state 2 to state 1 transition. The general physiological relevance of the SM rise is supported by its occurrence in several cyanobacterial strains: Synechococcus (PCC 7942, WH 5701) and diazotrophic single cell cyanobacterium (Cyanothece sp. ATCC 51142). We also show here that the SM fluorescence rise, and also the state transition changes are less prominent in filamentous diazotrophic cyanobacterium Nostoc sp. (PCC 7120) and absent in phycobilisome-less cyanobacterium Prochlorococcus marinus PCC 9511. Surprisingly, it is also absent in the phycobiliprotein rod containing Acaryochloris marina (MBIC 11017). All these results show that the S to M fluorescence rise reflects state 2 to state 1 transition in cyanobacteria with phycobilisomes formed by rods and core parts. We show that the pronounced SM fluorescence rise may reflect a protective mechanism for excess energy dissipation in those cyanobacteria (e.g. in Synechococcus PCC 7942) that are less efficient in other protective mechanisms, such as blue light induced non-photochemical quenching. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.
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Affiliation(s)
- Radek Kaňa
- Institute of Microbiology, Academy of Sciences, Třeboň, Czech Republic.
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Papageorgiou GC, Govindjee. Photosystem II fluorescence: slow changes--scaling from the past. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 104:258-70. [PMID: 21530301 DOI: 10.1016/j.jphotobiol.2011.03.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 03/14/2011] [Accepted: 03/14/2011] [Indexed: 11/25/2022]
Abstract
With the advent of photoelectric devices (photocells, photomultipliers) in the 1930s, fluorometry of chlorophyll (Chl) a in vivo emerged as a major method in the science of photosynthesis. Early researchers employed fluorometry primarily for two tasks: to elucidate the role in photosynthesis, if any, of other plant pigments, such as Chl b, Chl c, carotenoids and phycobilins; and to use it as a convenient inverse measure of photosynthetic activity. In pursuing the latter task, it became apparent that Chl a fluorescence emission is influenced (i) by redox active Chl a molecules in the reaction center of photosystem (PS) II (photochemical quenching); (ii) by an electrochemical imbalance across the thylakoid membrane (high energy quenching); and (iii) by the size of the peripheral antennae of weakly fluorescent PSI and strongly fluorescent PSII in response to changes in the ambient light (state transitions). In this perspective we trace the historical evolution of our awareness of these concepts, particularly of the so-called 'State Transitions'.
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Affiliation(s)
- George C Papageorgiou
- National Center of Scientific Research Demokritos, Institute of Biology, Athens 15310, Greece.
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Shevela D. Adventures with cyanobacteria: a personal perspective. FRONTIERS IN PLANT SCIENCE 2011; 2:28. [PMID: 22645530 PMCID: PMC3355777 DOI: 10.3389/fpls.2011.00028] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Accepted: 06/21/2011] [Indexed: 05/08/2023]
Abstract
Cyanobacteria, or the blue-green algae as they used to be called until 1974, are the oldest oxygenic photosynthesizers. We summarize here adventures with them since the early 1960s. This includes studies on light absorption by cyanobacteria, excitation energy transfer at room temperature down to liquid helium temperature, fluorescence (kinetics as well as spectra) and its relationship to photosynthesis, and afterglow (or thermoluminescence) from them. Further, we summarize experiments on their two-light reaction - two-pigment system, as well as the unique role of bicarbonate (hydrogen carbonate) on the electron-acceptor side of their photosystem II, PSII. This review, in addition, includes a discussion on the regulation of changes in phycobilins (mostly in PSII) and chlorophyll a (Chl a; mostly in photosystem I, PSI) under oscillating light, on the relationship of the slow fluorescence increase (the so-called S to M rise, especially in the presence of diuron) in minute time scale with the so-called state-changes, and on the possibility of limited oxygen evolution in mixotrophic PSI (minus) mutants, up to 30 min, in the presence of glucose. We end this review with a brief discussion on the position of cyanobacteria in the evolution of photosynthetic systems.
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Spectral characteristic of fluorescence induction in a model cyanobacterium, Synechococcus sp. (PCC 7942). BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:1170-8. [PMID: 19410552 DOI: 10.1016/j.bbabio.2009.04.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 03/24/2009] [Accepted: 04/15/2009] [Indexed: 11/24/2022]
Abstract
We present here three-dimensional time-wavelength-intensity displays of changes in variable fluorescence, during the O(JI)PSMT transient, observed in cyanobacterium at room temperature. We were able to measure contributions of individual chromophores to fluorescence spectra at various times of fluorescence induction (FI). The method was applied to a freshwater cyanobacterium, Synechococcus sp. (PCC 7942). Analysis of our experimental results provides the following new conclusions: (i) the main chlorophyll (Chl) a emission band at approximately 685 nm that originates in Photosystem (PS) II exhibits typical fast (OPS) and slow (SMT) FI kinetics with both orange (622 nm) and blue (464 nm) excitation. (ii) Similar kinetics are exhibited for its far-red emission satellite band centered at approximately 745 nm, where the PS II contribution predominates. (iii) A significant OPS-SMT-type kinetics of C-phycocyanin emission at approximately 650 nm are observed with the blue light excitation, but not with orange light excitation where the signal rose only slightly to a maximum. The induction of F650 was not caused by an admixture of the F685 fluorescence and thus our data show light-inducible and dark-reversible changes of phycobilin fluorescence in vivo. We discuss possible interpretations of this new observation.
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