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Kale RS, Seep JL, Sallans L, Frankel LK, Bricker TM. Oxidative modification of LHC II associated with photosystem II and PS I-LHC I-LHC II membranes. PHOTOSYNTHESIS RESEARCH 2022; 152:261-274. [PMID: 35179681 DOI: 10.1007/s11120-022-00902-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 02/01/2022] [Indexed: 05/22/2023]
Abstract
Under aerobic conditions the production of Reactive Oxygen Species (ROS) by electron transport chains is unavoidable, and occurs in both autotrophic and heterotrophic organisms. In photosynthetic organisms both Photosystem II (PS II) and Photosystem I (PS I), in addition to the cytochrome b6/f complex, are demonstrated sources of ROS. All of these membrane protein complexes exhibit oxidative damage when isolated from field-grown plant material. An additional possible source of ROS in PS I and PS II is the distal, chlorophyll-containing light-harvesting array LHC II, which is present in both photosystems. These serve as possible sources of 1O2 produced by the interaction of 3O2 with 3chl* produced by intersystem crossing. We have hypothesized that amino acid residues close to the sites of ROS generation will be more susceptible to oxidative modification than distant residues. In this study, we have identified oxidized amino acid residues in a subset of the spinach LHC II proteins (Lhcb1 and Lhcb2) that were associated with either PS II membranes (i.e. BBYs) or PS I-LHC I-LHC II membranes, both of which were isolated from field-grown spinach. We identified oxidatively modified residues by high-resolution tandem mass spectrometry. Interestingly, two different patterns of oxidative modification were evident for the Lhcb1 and Lhcb2 proteins from these different sources. In the LHC II associated with PS II membranes, oxidized residues were identified to be located on the stromal surface of Lhcb1 and, to a much lesser extent, Lhcb2. Relatively few oxidized residues were identified as buried in the hydrophobic core of these proteins. The LHC II associated with PS I-LHC I-LHC II membranes, however, exhibited fewer surface-oxidized residues but, rather a large number of oxidative modifications buried in the hydrophobic core regions of both Lhcb1 and Lhcb2, adjacent to the chlorophyll prosthetic groups. These results appear to indicate that ROS, specifically 1O2, can modify the Lhcb proteins associated with both photosystems and that the LHC II associated with PS II membranes represent a different population from the LHC II associated with PS I-LHC I-LHC II membranes.
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Affiliation(s)
- Ravindra S Kale
- Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Jacob L Seep
- Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Larry Sallans
- The Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Laurie K Frankel
- Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Terry M Bricker
- Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, LA, 70803, USA.
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2
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Kale R, Sallans L, Frankel LK, Bricker TM. Natively oxidized amino acid residues in the spinach PS I-LHC I supercomplex. PHOTOSYNTHESIS RESEARCH 2020; 143:263-273. [PMID: 31894498 DOI: 10.1007/s11120-019-00698-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 12/05/2019] [Indexed: 06/10/2023]
Abstract
Reactive oxygen species (ROS) production is an unavoidable byproduct of electron transport under aerobic conditions. Photosystem II (PS II), the cytochrome b6/f complex and Photosystem I (PS I) are all demonstrated sources of ROS. It has been proposed that PS I produces substantial levels of a variety of ROS including O2.-, 1O2, H2O2 and, possibly, •OH; however, the site(s) of ROS production within PS I has been the subject of significant debate. We hypothesize that amino acid residues close to the sites of ROS generation will be more susceptible to oxidative modification than distant residues. In this study, we have identified oxidized amino acid residues in spinach PS I which was isolated from field-grown spinach. The modified residues were identified by high-resolution tandem mass spectrometry. As expected, many of the modified residues lie on the surface of the complex. However, a well-defined group of oxidized residues, both buried and surface-exposed, lead from the chl a' of P700 to the surface of PS I. These residues (PsaB: 609F, 611E, 617M, 619W, 620L, and PsaF: 139L, 142A,143D) may identify a preferred route for ROS, probably 1O2, to egress the complex from the vicinity of P700. Additionally, two buried residues located in close proximity to A1B (PsaB:712H and 714S) were modified, which appears consistent with A1B being a source of O2.-. Surprisingly, no oxidatively modified residues were identified in close proximity to the 4Fe-FS clusters FX, FA or FB. These cofactors had been identified as principal targets for ROS damage in the photosystem. Finally, a large number of residues located in the hydrophobic cores of Lhca1-Lhca4 are oxidatively modified. These appear to be the result of 1O2 production by the distal antennae for the photosystem.
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Affiliation(s)
- Ravindra Kale
- Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Larry Sallans
- The Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Laurie K Frankel
- Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Terry M Bricker
- Department of Biological Sciences, Biochemistry and Molecular Biology Section, Louisiana State University, Baton Rouge, LA, 70803, USA.
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Zhao F, Hardt S, Hartmann V, Zhang H, Nowaczyk MM, Rögner M, Plumeré N, Schuhmann W, Conzuelo F. Light-induced formation of partially reduced oxygen species limits the lifetime of photosystem 1-based biocathodes. Nat Commun 2018; 9:1973. [PMID: 29773789 PMCID: PMC5958124 DOI: 10.1038/s41467-018-04433-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/26/2018] [Indexed: 12/15/2022] Open
Abstract
Interfacing photosynthetic proteins specifically photosystem 1 (PS1) with electrodes enables light-induced charge separation processes for powering semiartificial photobiodevices with, however, limited long-term stability. Here, we present the in-depth evaluation of a PS1/Os-complex-modified redox polymer-based biocathode by means of scanning photoelectrochemical microscopy. Focalized local illumination of the bioelectrode and concomitant collection of H2O2 at the closely positioned microelectrode provide evidence for the formation of partially reduced oxygen species under light conditions. Long-term evaluation of the photocathode at different O2 concentrations as well as after incorporating catalase and superoxide dismutase reveals the particularly challenging issue of avoiding the generation of reactive species. Moreover, the evaluation of films prepared with inactivated PS1 and free chlorophyll points out additional possible pathways for the generation of oxygen radicals. To avoid degradation of PS1 during illumination and hence to enhance the long-term stability, the operation of biophotocathodes under anaerobic conditions is indispensable.
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Affiliation(s)
- Fangyuan Zhao
- Analytical Chemistry - Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstr. 150, Bochum, 44780, Germany
| | - Steffen Hardt
- Center for Electrochemical Sciences - Molecular Nanostructures, Ruhr-Universität Bochum, Universitätsstr. 150, Bochum, 44780, Germany
| | - Volker Hartmann
- Plant Biochemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44780, Bochum, Germany
| | - Huijie Zhang
- Center for Electrochemical Sciences - Molecular Nanostructures, Ruhr-Universität Bochum, Universitätsstr. 150, Bochum, 44780, Germany
| | - Marc M Nowaczyk
- Plant Biochemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44780, Bochum, Germany
| | - Matthias Rögner
- Plant Biochemistry, Ruhr-Universität Bochum, Universitätsstr. 150, 44780, Bochum, Germany
| | - Nicolas Plumeré
- Center for Electrochemical Sciences - Molecular Nanostructures, Ruhr-Universität Bochum, Universitätsstr. 150, Bochum, 44780, Germany
| | - Wolfgang Schuhmann
- Analytical Chemistry - Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstr. 150, Bochum, 44780, Germany.
| | - Felipe Conzuelo
- Analytical Chemistry - Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstr. 150, Bochum, 44780, Germany.
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Dobrev K, Stanoeva D, Velitchkova M, Popova AV. The Lack of Lutein Accelerates the Extent of Light-induced Bleaching of Photosynthetic Pigments in Thylakoid Membranes of Arabidopsis thaliana. Photochem Photobiol 2016; 92:436-45. [PMID: 26888623 DOI: 10.1111/php.12576] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/24/2016] [Indexed: 11/30/2022]
Abstract
The high light-induced bleaching of photosynthetic pigments and the degradation of proteins of light-harvesting complexes of PSI and PSII were investigated in isolated thylakoid membranes of Arabidopsis thaliana, wt and lutein-deficient mutant lut2, with the aim of unraveling the role of lutein for the degree of bleaching and degradation. By the means of absorption spectroscopy and western blot analysis, we show that the lack of lutein leads to a higher extent of pigment photobleaching and protein degradation in mutant thylakoid membranes in comparison with wt. The highest extent of bleaching is suffered by chlorophyll a and carotenoids, while chlorophyll b is bleached in lut2 thylakoids during long periods at high illumination. The high light-induced degradation of Lhca1, Lhcb2 proteins and PsbS was followed and it is shown that Lhca1 is more damaged than Lhcb2. The degradation of analyzed proteins is more pronounced in lut2 mutant thylakoid membranes. The lack of lutein influences the high light-induced alterations in organization of pigment-protein complexes as revealed by 77 K fluorescence.
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Affiliation(s)
- Konstantin Dobrev
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. Bl. 21, Sofia, 1113, Bulgaria
| | - Daniela Stanoeva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. Bl. 21, Sofia, 1113, Bulgaria
| | - Maya Velitchkova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. Bl. 21, Sofia, 1113, Bulgaria
| | - Antoaneta V Popova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. Bl. 21, Sofia, 1113, Bulgaria
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Hasni I, Msilini N, Hamdani S, Tajmir-Riahi HA, Carpentier R. Characterization of the structural changes and photochemical activity of photosystem I under Al(3+) effect. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 149:292-9. [PMID: 26123191 DOI: 10.1016/j.jphotobiol.2015.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/08/2015] [Accepted: 06/14/2015] [Indexed: 11/27/2022]
Abstract
The photochemical activity of photosystem I (PSI) as affected by Al(3+) was investigated in thylakoid membranes and PSI submembrane fractions isolated from spinach. Biophysical and biochemical techniques such as oxygen uptake, light induced absorbance changes at 820nm, chlorophyll fluorescence emission, SDS-polyacrylamide gel electrophoresis, and FTIR spectroscopy have been used to analyze the sites and action modes of this cation on the PSI complex. Our results showed that Al(3+) above 3mM induces changes in the redox state of P700 reflected by an increase of P700 photooxidation phase and a delay of the slower rate of P700 re-reduction which reveals that Al(3+) exerted an inhibitory action at the donor side of PSI especially at plastocyanin (PC). Furthermore, results of P700 photooxidation monitored in the presence of DCMU with or without MV suggested that the same range of Al(3+) concentrations impairs the photochemical reaction centers (RC) of PSI, as shown by the decline in the amount of active population of P700, and disrupts the charge separation between P700 and the primary electron acceptor A0 leading to the inhibition of electron transfer at the acceptor side of PSI. These inhibitory actions were also accompanied by an impairment of the energy transfer from light harvesting complex (LHCI) to RC of PSI, following the disconnection of LHCI antenna as illustrated by an enhancement of chlorophyll fluorescence emission spectra at low temperature (77K). The above results coincided with FTIR measurements that indicated a conformational change of the protein secondary structures in PSI complex where 25% of α-helix was converted into β-sheet, β-antiparallel and turn structures. These structural changes in PSI complex proteins are closely related with the alteration photochemical activity of PSI including the inhibition of the electron transport through both acceptor and donor sides of PSI.
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Affiliation(s)
- Imed Hasni
- Groupe de Recherche en Biologie Végétale, Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Qc G9A 5H7, Canada
| | - Najoua Msilini
- Laboratory of Physiology and Biochemistry of Salt Tolerance in Plants, Faculty of Sciences of Tunis, Campus University, 1060, Tunisia
| | - Saber Hamdani
- Plant Systems Biology Group, Partner Institute of Computational Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Heidar-Ali Tajmir-Riahi
- Groupe de Recherche en Biologie Végétale, Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Qc G9A 5H7, Canada
| | - Robert Carpentier
- Groupe de Recherche en Biologie Végétale, Département de Chimie, Biochimie et Physique, Université du Québec à Trois-Rivières, Trois-Rivières, Qc G9A 5H7, Canada.
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Yaakoubi H, Hamdani S, Bekalé L, Carpentier R. Protective action of spermine and spermidine against photoinhibition of photosystem I in isolated thylakoid membranes. PLoS One 2014; 9:e112893. [PMID: 25420109 PMCID: PMC4242612 DOI: 10.1371/journal.pone.0112893] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 10/16/2014] [Indexed: 11/18/2022] Open
Abstract
The photo-stability of photosystem I (PSI) is of high importance for the photosynthetic processes. For this reason, we studied the protective action of two biogenic polyamines (PAs) spermine (Spm) and spermidine (Spd) on PSI activity in isolated thylakoid membranes subjected to photoinhibition. Our results show that pre-loading thylakoid membranes with Spm and Spd reduced considerably the inhibition of O2 uptake rates, P700 photooxidation and the accumulation of superoxide anions (O2(-)) induced by light stress. Spm seems to be more effective than Spd in preserving PSI photo-stability. The correlation of the extent of PSI protection, photosystem II (PSII) inhibition and O2(-) generation with increasing Spm doses revealed that PSI photo-protection is assumed by two mechanisms depending on the PAs concentration. Given their antioxidant character, PAs scavenge directly the O2(-) generated in thylakoid membranes at physiological concentration (1 mM). However, for non-physiological concentration, the ability of PAs to protect PSI is due to their inhibitory effect on PSII electron transfer.
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Affiliation(s)
- Hnia Yaakoubi
- Groupe de Recherche en Biologie-Végétale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Saber Hamdani
- Groupe de Recherche en Biologie-Végétale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Laurent Bekalé
- Groupe de Recherche en Biologie-Végétale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Robert Carpentier
- Groupe de Recherche en Biologie-Végétale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
- * E-mail:
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7
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Yu D, Huang G, Xu F, Ge B, Liu S, Xu H, Huang F. Effect of surfactants on apparent oxygen consumption of photosystem I isolated from Arthrospira platensis. PHOTOSYNTHESIS RESEARCH 2014; 122:203-213. [PMID: 24947956 DOI: 10.1007/s11120-014-0022-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 05/29/2014] [Indexed: 06/03/2023]
Abstract
Surfactants play a significant role in solubilization of photosystem I (PSI) in vitro. Triton X-100 (TX), n-Dodecyl-β-D-maltoside (DDM), and sodium dodecyl sulfate (SDS) were employed to solubilize PSI particles in MES buffer to compare the effect of surfactant and its dosage on the apparent oxygen consumption rate of PSI. Through a combined assessment of sucrose density gradient centrifugation, Native PAGE and 77 K fluorescence with the apparent oxygen consumption, the nature of the enhancement of the apparent oxygen consumption activity of PSI by surfactants has been analyzed. Aggregated PSI particles can be dispersed by surfactant molecules into micelles, and the apparent oxygen consumption rate is higher for surfactant-solubilized PSI than for integral PSI particles. For DDM, PSI particles are solubilized mostly as the integral trimeric form. For TX, PSI particles are solubilized as incomplete trimeric and some monomeric forms. For the much harsher surfactant, SDS, PSI particles are completely solubilized as monomeric and its subunit forms. The enhancement of the oxygen consumption rate cannot be explained only by the effects of surfactant on the equilibrium between monomeric and trimeric forms of solubililized PSI. Care must be taken when the electron transfer activity of PSI is evaluated by methods based on oxygen consumption because the apparent oxygen consumption rate is influenced by uncoupled chlorophyll (Chl) from PSI, i.e., the larger the amount of uncoupled Chl, the higher the rate of apparent oxygen consumption. 77 K fluorescence spectra can be used to ensure that there is no uncoupled Chl present in the system. In order to eliminate the effect of trace uncoupled Chl, an efficient physical quencher of (1)O2, such as 1 mM NaN3, may be added into the mixture.
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Affiliation(s)
- Daoyong Yu
- State Key Laboratory of Heavy Oil Processing, Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, 266580, Shandong, China,
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Effect of biogenic polyamine spermine on the structure and function of photosystem I. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 141:76-83. [PMID: 25318020 DOI: 10.1016/j.jphotobiol.2014.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 11/22/2022]
Abstract
We located the binding sites of spermine (Spm) to PSI sub-membrane proteins and the impact of this interaction on the photoprotection of PSI activity, using spectroscopic methods and molecular modeling. Our results showed that at high Spm content the polyamine binds PSI polypeptides through H-bonding and induces major protein conformational changes with the reduction of α-helix from 52% to 42% and an increase of the β-sheet from 26% to 29%. However, polyamine does not affect significantly the photooxidizable P700 in control sample and considerably protects it against strong illumination. On the contrary, protein conformational changes coincide with an important inhibition of O2 uptake rates by polyamine, which revealed that the protein of the PSI donor side plastocyanin is a main target for Spm inhibition. The photoprotection of PSI photochemical activity may be due to the stabilization of the PSI stromal polypeptides by Spm as shown by the docking results. Spm binds to different amino acids with hydrophilic and hydrophobic characters, while the presence of several H-bondings stabilizes Spm-PSI complexation.
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Wang Y, Zhang J, Yu J, Jiang X, Sun L, Wu M, Chen G, Lv C. Photosynthetic changes of flag leaves during senescence stage in super high-yield hybrid rice LYPJ grown in field condition. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 82:194-201. [PMID: 24976603 DOI: 10.1016/j.plaphy.2014.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/10/2014] [Indexed: 06/03/2023]
Abstract
Photosynthetic activities and thylakoid membrane protein patterns as well as the ultrastructure of chloroplasts in flag leaves were investigated during the senescence processes in high-yield hybrid rice LYPJ under field condition. The earlier decrease of PS I activity than PS II in LYPJ was primarily due to the significant degradation of PS I chlorophyll-protein complex. The degradation rate for each chlorophyll-protein complex was different and the order for the stability of thylakoid membrane complexes during flag leaf senescence in rice LYPJ was: LHCII > OEC > PSII core antenna > PSII core > PSI core > LHCI, which was partly supported by the BN-PAGE gel combined with immunoblot analysis. A decrease in the chlorophyll a/b ratio at the senescence stage was observed to coincide with stability of the LHCII subunits. Ultrastructural investigations revealed that the chloroplasts have large loosen stacking grana without interconnecting stroma thylakoids during the senescence processes. It was hypothesized that the stability of grana thylakoids harboring the major LHCII under high radiation condition in summer might played a key role in the dissipation of excess light energy. This alternative strategy would protect photosynthetic apparatus from photodamage and might be causally related to the high yield of this rice cultivar.
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Affiliation(s)
- Yuwen Wang
- Jiangsu Key Laboratory of Biodiversity and Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210023, China
| | - Jingjing Zhang
- Jiangsu Key Laboratory of Biodiversity and Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210023, China
| | - Jing Yu
- Jiangsu Key Laboratory of Biodiversity and Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210023, China
| | - Xiaohan Jiang
- Jiangsu Key Laboratory of Biodiversity and Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210023, China
| | - Lingang Sun
- Jiangsu Key Laboratory of Biodiversity and Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210023, China
| | - Min Wu
- Jiangsu Key Laboratory of Biodiversity and Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210023, China; Zijin College, Nanjing University of Science and Technology, Nanjing 210023, China
| | - Guoxiang Chen
- Jiangsu Key Laboratory of Biodiversity and Biotechnology, Life Sciences College, Nanjing Normal University, Nanjing 210023, China.
| | - Chuangen Lv
- Institute of Food and Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
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Abstract
In oxygenic photosynthetic eukaryotes, the hydroxylated carotenoid zeaxanthin is produced from preexisting violaxanthin upon exposure to excess light conditions. Zeaxanthin binding to components of the photosystem II (PSII) antenna system has been investigated thoroughly and shown to help in the dissipation of excess chlorophyll-excited states and scavenging of oxygen radicals. However, the functional consequences of the accumulation of the light-harvesting complex I (LHCI) proteins in the photosystem I (PSI) antenna have remained unclarified so far. In this work we investigated the effect of zeaxanthin binding on photoprotection of PSI-LHCI by comparing preparations isolated from wild-type Arabidopsis thaliana (i.e., with violaxanthin) and those isolated from the A. thaliana nonphotochemical quenching 2 mutant, in which violaxanthin is replaced by zeaxanthin. Time-resolved fluorescence measurements showed that zeaxanthin binding leads to a previously unrecognized quenching effect on PSI-LHCI fluorescence. The efficiency of energy transfer from the LHCI moiety of the complex to the PSI reaction center was down-regulated, and an enhanced PSI resistance to photoinhibition was observed both in vitro and in vivo. Thus, zeaxanthin was shown to be effective in inducing dissipative states in PSI, similar to its well-known effect on PSII. We propose that, upon acclimation to high light, PSI-LHCI changes its light-harvesting efficiency by a zeaxanthin-dependent quenching of the absorbed excitation energy, whereas in PSII the stoichiometry of LHC antenna proteins per reaction center is reduced directly.
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11
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Krumova SB, Várkonyi Z, Lambrev PH, Kovács L, Todinova SJ, Busheva MC, Taneva SG, Garab G. Heat- and light-induced detachment of the light-harvesting antenna complexes of photosystem I in isolated stroma thylakoid membranes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 137:4-12. [PMID: 24912404 DOI: 10.1016/j.jphotobiol.2014.04.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 04/22/2014] [Accepted: 04/25/2014] [Indexed: 11/15/2022]
Abstract
The multisubunit pigment-protein complex of photosystem I (PSI) consists of a core and peripheral light-harvesting antenna (LHCI). PSI is thought to be a rather rigid system and very little is known about its structural and functional flexibility. Recent data, however, suggest LHCI detachment from the PSI supercomplex upon heat and light treatments. Furthermore, it was suggested that the splitting off of LHCI acts as a safety valve for PSI core upon photoinhibition (Alboresi et al., 2009). In this work we analyzed the heat- and light-induced reorganizations in isolated PSI vesicles (stroma membrane vesicles enriched in PSI). Using differential scanning calorimetry we revealed a stepwise disassembly of PSI supercomplex above 50°C. Circular dichroism, sucrose gradient centrifugation and 77K fluorescence experiments identified the sequence of events of PSI destabilization: 3min heating at 60°C or 40min white light illumination at 25°C resulted in pronounced Lhca1/4 detachment from the PSI supercomplex, which is then followed by the degradation of Lhca2/3. The similarity of the main structural effects due to heat and light treatments supports the notion that thermo-optic mechanism, structural changes induced by ultrafast local thermal transients, which has earlier been shown to be responsible for structural changes in the antenna system of photosystem II, can also regulate the assembly and functioning of PSI antenna.
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Affiliation(s)
- S B Krumova
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Zs Várkonyi
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - P H Lambrev
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - L Kovács
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - S J Todinova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - M C Busheva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - S G Taneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - G Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary.
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Kettles NL, Kopriva S, Malin G. Insights into the regulation of DMSP synthesis in the diatom Thalassiosira pseudonana through APR activity, proteomics and gene expression analyses on cells acclimating to changes in salinity, light and nitrogen. PLoS One 2014; 9:e94795. [PMID: 24733415 PMCID: PMC3986220 DOI: 10.1371/journal.pone.0094795] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 03/20/2014] [Indexed: 01/05/2023] Open
Abstract
Despite the importance of dimethylsulphoniopropionate (DMSP) in the global sulphur cycle and climate regulation, the biological pathways underpinning its synthesis in marine phytoplankton remain poorly understood. The intracellular concentration of DMSP increases with increased salinity, increased light intensity and nitrogen starvation in the diatom Thalassiosira pseudonana. We used these conditions to investigate DMSP synthesis at the cellular level via analysis of enzyme activity, gene expression and proteome comparison. The activity of the key sulphur assimilatory enzyme, adenosine 5′-phosphosulphate reductase was not coordinated with increasing intracellular DMSP concentration. Under all three treatments coordination in the expression of sulphur assimilation genes was limited to increases in sulphite reductase transcripts. Similarly, proteomic 2D gel analysis only revealed an increase in phosphoenolpyruvate carboxylase following increases in DMSP concentration. Our findings suggest that increased sulphur assimilation might not be required for increased DMSP synthesis, instead the availability of carbon and nitrogen substrates may be important in the regulation of this pathway. This contrasts with the regulation of sulphur metabolism in higher plants, which generally involves up-regulation of several sulphur assimilatory enzymes. In T. pseudonana changes relating to sulphur metabolism were specific to the individual treatments and, given that little coordination was seen in transcript and protein responses across the three growth conditions, different patterns of regulation might be responsible for the increase in DMSP concentration seen under each treatment.
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Affiliation(s)
- Nicola Louise Kettles
- Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
- John Innes Centre, Norwich, United Kingdom
| | | | - Gill Malin
- Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
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Yadavalli V, Neelam S, Rao ASVC, Reddy AR, Subramanyam R. Differential degradation of photosystem I subunits under iron deficiency in rice. JOURNAL OF PLANT PHYSIOLOGY 2012; 169:753-9. [PMID: 22445751 DOI: 10.1016/j.jplph.2012.02.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Revised: 02/22/2012] [Accepted: 02/23/2012] [Indexed: 05/05/2023]
Abstract
Rice (Oryza sativa) is one of the staple foods of the world. Iron (Fe) deficiency is a major abiotic stress factor that contributes world-wide to losses in crop yield and decline in nutritional quality. As cofactor for many enzymes and proteins, iron is an essential element. It plays a pivotal role in chlorophyll (Chl) biosynthesis, and iron deficiency may result in decreased Chl production and, thus, reduced photosynthetic capacity. Photosystem I (PSI) is a prime target of iron deficiency because of its high iron content (12 Fe per PS). To understand the protein level changes in the light-harvesting complex (LHC) of PSI (LHCI) under iron deficiency, rice seedlings were grown in Hoagland's nutrient medium with and without Fe. Chlorophyll content and photosynthetic efficiency decreased under iron deficiency. Protein gel blots probed with antibodies against the PSI core and Lhca 1-4 proteins revealed that the core subunits PsaA and PsaB remained stable under iron deficiency, whereas PsaC and PsaD decreased by about 50%, and PsaE was completely degraded. Among the LHCI subunits, Lhca1 and Lhca2 decreased by 40 and 50%, respectively, whereas Lhca3 and Lhca4 were completely degraded. We propose that the dissociation of LHCI subunits may be due to increased levels of reactive oxygen species, which is suggested by the increased activity of superoxide dismutase.
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Affiliation(s)
- Venkateswarlu Yadavalli
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
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Liu J, Zhang X, Wang M, Liu J, Cao M, Lu J, Cui Z. Characterization of photosystem I from spinach: effect of solution pH. PHOTOSYNTHESIS RESEARCH 2012; 112:63-70. [PMID: 22477469 DOI: 10.1007/s11120-012-9737-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 03/19/2012] [Indexed: 05/31/2023]
Abstract
Our previous work has demonstrated the isolation of photosystem I (PSI) from spinach using ultrafiltration with a final purity of 84%. In order to get a higher purity of PSI and more importantly to develop a practical bioseparation process, key physiochemical properties of PSI and their dependence on operational parameters must be assessed. In this study, the effect of solution pH, one of the most important operating parameters for membrane process, on the property of PSI was examined. Following the isolation of crude PSI from spinach using n-dodecyl-beta-D: -maltoside as detergent, the isoelectric point, aggregation size, zeta potential, low-temperature fluorescence, atomic force microscopy imaging, secondary structure, and thermal stability were determined. Solution pH was found to have a significant effect on the activity, aggregation size and thermal stability of PSI. The results also suggested that the activity of PSI was related to its aggregation size.
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Affiliation(s)
- Jianguo Liu
- Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266555, People's Republic of China.
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15
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Abstract
The photoinhibition of Photosystem I (PSI) drew less attention compared with that of Photosystem II (PSII). This could be ascribed to several reasons, e.g. limited combinations of plant species and environmental conditions that cause PSI photoinhibition, the non-regulatory aspect of PSI photoinhibition, and methodological difficulty to determine the accurate activity of PSI under stress conditions. However, the photoinhibition of PSI could be more dangerous than that of PSII because of the very slow recovery rate of PSI. This article is intended to introduce such characteristics of PSI photoinhibition with special emphasis on the relationship between two photosystems as well as the protective mechanism of PSI in vivo. Although the photoinhibition of PSI could be induced only in specific conditions and specific plant species in intact leaves, PSI itself is quite susceptible to photoinhibition in isolated thylakoid membranes. PSI seems to be well protected from photoinhibition in vivo in many plant species and many environmental conditions. This is quite understandable because photoinhibition of PSI is not only irreversible but also the potential cause of many secondary damages. This point would be different from the case of PSII photoinhibition, which could be regarded as one of the regulatory mechanisms under stressed as well as non-stressed conditions.
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Affiliation(s)
- Kintake Sonoike
- Faculty of Education and Integrated Arts and Sciences, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
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The light-harvesting complexes of higher-plant Photosystem I: Lhca1/4 and Lhca2/3 form two red-emitting heterodimers. Biochem J 2011; 433:477-85. [PMID: 21083539 DOI: 10.1042/bj20101538] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The outer antenna of higher-plant PSI (Photosystem I) is composed of four complexes [Lhc (light-harvesting complex) a1-Lhca4] belonging to the light-harvesting protein family. Difficulties in their purification have so far prevented the determination of their properties and most of the knowledge about Lhcas has been obtained from the study of the in vitro reconstituted antennas. In the present study we were able to purify the native complexes, showing that Lhca2/3 and Lhca1/4 form two functional heterodimers. Both dimers show red-fluorescence emission with maxima around 730 nm, as in the intact PSI complex. This indicates that the dimers are in their native state and that LHCI-680, which was previously assumed to be part of the PSI antenna, does not represent the native state of the system. The data show that the light-harvesting properties of the two dimers are functionally identical, concerning absorption, long-wavelength emission and fluorescence quantum yield, whereas they differ in their high-light response. Implications of the present study for the understanding of the energy transfer process in PSI are discussed. Finally, the comparison of the properties of the native dimers with those of the reconstituted complexes demonstrates that all of the major properties of the Lhcas are reproduced in the in vitro systems.
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Qin X, Wang W, Wang K, Xin Y, Kuang T. Isolation and characteristics of the PSI-LHCI-LHCII supercomplex under high light. Photochem Photobiol 2010; 87:143-50. [PMID: 21077900 DOI: 10.1111/j.1751-1097.2010.00830.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We developed a novel method for the isolation of the PSI-LHCI-LHCII complex from spinach leaves. The supercomplex was resolved into a core complex (CPI), LHCII trimers, LHCI dimers and LHCII monomers using green gel electrophoresis. We then investigate changes in the fluorescence and absorption spectra of PSI-LHCI-LHCII under high light. In addition, we compared light-induced denaturation of the core protein subunits in both PSI-LHCI and PSI-LHCI-LHCII. Differences in denaturation and photochemical activity indicated that binding of LHCII increased the photosensitivity of the PSI core. Increased energy delivered to the PSI core during illumination accelerated damage to the core complex.
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Affiliation(s)
- Xiaochun Qin
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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Matsumoto K, Zhang S, Koutsopoulos S. Enhanced Electron Transfer Activity of Photosystem I by Polycations in Aqueous Solution. Biomacromolecules 2010; 11:3152-7. [DOI: 10.1021/bm100950g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kazuya Matsumoto
- Center for Biomedical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, United States, and Mitsui Chemicals, Inc., Catalysis Science Laboratory, 1144 Togo, Mobara-shi, Chiba 297-0017, Japan
| | - Shuguang Zhang
- Center for Biomedical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, United States, and Mitsui Chemicals, Inc., Catalysis Science Laboratory, 1144 Togo, Mobara-shi, Chiba 297-0017, Japan
| | - Sotirios Koutsopoulos
- Center for Biomedical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, United States, and Mitsui Chemicals, Inc., Catalysis Science Laboratory, 1144 Togo, Mobara-shi, Chiba 297-0017, Japan
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Alboresi A, Ballottari M, Hienerwadel R, Giacometti GM, Morosinotto T. Antenna complexes protect Photosystem I from photoinhibition. BMC PLANT BIOLOGY 2009; 9:71. [PMID: 19508723 PMCID: PMC2704212 DOI: 10.1186/1471-2229-9-71] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Accepted: 06/09/2009] [Indexed: 05/20/2023]
Abstract
BACKGROUND Photosystems are composed of two moieties, a reaction center and a peripheral antenna system. In photosynthetic eukaryotes the latter system is composed of proteins belonging to Lhc family. An increasing set of evidences demonstrated how these polypeptides play a relevant physiological function in both light harvesting and photoprotection. Despite the sequence similarity between antenna proteins associated with the two Photosystems, present knowledge on their physiological role is mostly limited to complexes associated to Photosystem II. RESULTS In this work we analyzed the physiological role of Photosystem I antenna system in Arabidopsis thaliana both in vivo and in vitro. Plants depleted in individual antenna polypeptides showed a reduced capacity for photoprotection and an increased production of reactive oxygen species upon high light exposure. In vitro experiments on isolated complexes confirmed that depletion of antenna proteins reduced the resistance of isolated Photosystem I particles to high light and that the antenna is effective in photoprotection only upon the interaction with the core complex. CONCLUSION We show that antenna proteins play a dual role in Arabidopsis thaliana Photosystem I photoprotection: first, a Photosystem I with an intact antenna system is more resistant to high light because of a reduced production of reactive oxygen species and, second, antenna chlorophyll-proteins are the first target of high light damages. When photoprotection mechanisms become insufficient, the antenna chlorophyll proteins act as fuses: LHCI chlorophylls are degraded while the reaction center photochemical activity is maintained. Differences with respect to photoprotection strategy in Photosystem II, where the reaction center is the first target of photoinhibition, are discussed.
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Affiliation(s)
- Alessandro Alboresi
- Laboratoire de Génétique et Biophysique des Plantes – UMR 6191 CEA-CNRS-Université de la Méditerranée, Marseille, France
- Dipartimento di Biotecnologie, Università di Verona, Verona, Italy
| | | | - Rainer Hienerwadel
- Laboratoire de Génétique et Biophysique des Plantes – UMR 6191 CEA-CNRS-Université de la Méditerranée, Marseille, France
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Ventrella A, Catucci L, Agostiano A. Effect of aggregation state, temperature and phospholipids on photobleaching of photosynthetic pigments in spinach Photosystem II core complexes. Bioelectrochemistry 2008; 73:43-8. [DOI: 10.1016/j.bioelechem.2008.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Revised: 03/14/2008] [Accepted: 04/07/2008] [Indexed: 11/24/2022]
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Rajagopal S, Bukhov NG, Carpentier R. Photoinhibitory Light-induced Changes in the Composition of Chlorophyll-Protein Complexes and Photochemical Activity in Photosystem-I Submembrane Fractions¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2003)0770284plicit2.0.co2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ciobanu M, Kincaid HA, Lo V, Dukes AD, Kane Jennings G, Cliffel DE. Electrochemistry and photoelectrochemistry of photosystem I adsorbed on hydroxyl-terminated monolayers. J Electroanal Chem (Lausanne) 2007. [DOI: 10.1016/j.jelechem.2006.09.019] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Rajagopal S, Joly D, Gauthier A, Beauregard M, Carpentier R. Protective effect of active oxygen scavengers on protein degradation and photochemical function in photosystem I submembrane fractions during light stress. FEBS J 2005; 272:892-902. [PMID: 15691324 DOI: 10.1111/j.1742-4658.2004.04512.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The protective role of reactive oxygen scavengers against photodamage was studied in isolated photosystem (PS) I submembrane fractions illuminated (2000 microE x m(-2) x s(-1)) for various periods at 4 degrees C. The photochemical activity of the submembrane fractions measured as P700 photooxidation was significantly protected in the presence of histidine or n-propyl gallate. Chlorophyll photobleaching resulting in a decrease of absorbance and fluorescence, and a blue-shift of both absorbance and fluorescence maximum in the red region, was also greatly delayed in the presence of these scavengers. Western blot analysis revealed the light harvesting antenna complexes of PSI, Lhca2 and Lhca1, were more susceptible to strong light when compared to Lhca3 and Lhca4. The reaction-center proteins PsaB, PsaC, and PsaE were most sensitive to strong illumination while other polypeptides were less affected. Addition of histidine or n-propyl gallate lead to significant protection of reaction-center proteins as well as Lhca against strong illumination. Circular dichroism (CD) spectra revealed that the alpha-helix content decreased with increasing period of light exposure, whereas beta-strands, turns, and unordered structure increased. This unfolding was prevented with the addition of histidine or n-propyl gallate even after 10 h of strong illumination. Catalase or superoxide dismutase could not minimize the alteration of PSI photochemical activity and structure due to photodamage. The specific action of histidine and n-propyl gallate indicates that 1O2 was the main form of reactive oxygen species responsible for strong light-induced damage in PSI submembrane fractions.
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Affiliation(s)
- Subramanyam Rajagopal
- Groupe de Recherche en Biologie Végétale, Université du Québec à Trois-Rivières, Québec, Canada
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Velitchkova MY, Picorel R. Photobleaching of photosynthetic pigments in spinach thylakoid membranes. Effect of temperature, oxygen and DCMU. Biophys Chem 2004; 107:25-32. [PMID: 14871598 DOI: 10.1016/s0301-4622(03)00217-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2003] [Revised: 07/21/2003] [Accepted: 07/23/2003] [Indexed: 11/26/2022]
Abstract
The time dependence of photobleaching of photosynthetic pigments under high light illumination of isolated spinach thylakoid membranes at 22 and 4 degrees C was investigated. At 22 degrees C, the bleaching at 678, 472 and 436 nm was prominent but lowering the temperature up to 4 degrees C during illumination prevented the pigments from bleaching almost completely. The accelerating effect on pigment photobleaching by the presence of 3-(3,4 dichlorophenyl)-1,1-dimethyl-urea)-(DCMU), a well-known inhibitor of the electron transport and known to prevent photosystem I (PSI) and photosystem II (PSII) against photoinhibitory damage, was also suppressed at low temperature. At 22 degrees C in the presence and absence of DCMU, the decrease of the absorption at 678 and 472 nm was accompanied by a shift to the shorter wavelengths. To check the involvement of reactive oxygen species in the process, pigment photobleaching was followed in anaerobiosis. The effects of the three different environmental factors--light, temperature and DCMU--on the dynamics of photobleaching are discussed in terms of different susceptibility of the main pigment-protein complexes to photoinhibition.
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Affiliation(s)
- M Y Velitchkova
- Estacion Experimental de Aula Dei, CSIC, Apdo. 202, 50059 Zaragoza, Spain.
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Hwang HJ, Kim JH, Eu YJ, Moon BY, Cho SH, Lee CH. Photoinhibition of photosystem I is accelerated by dimethyldithiocarbamate, an inhibitor of superoxide dismutase, during light-chilling of spinach leaves. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2004; 73:79-85. [PMID: 14732254 DOI: 10.1016/j.jphotobiol.2003.09.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In vivo photoinhibition of photosystem I (PS I) was investigated at chilling temperature using the leaves of the chilling-resistant spinach plant treated with an inhibitor of superoxide dismutase, diethyldithiocarbamate (DDC). When spinach leaves were treated with DDC during chilling at 4 degrees C for 12 h with a light intensity of 120 micromol m(-2) s(-1), the activity of PS I and the content of iron-sulfur centers declined to about 50% and 25% of the non-DDC-treated controls, respectively. A native green gel analysis of thylakoid membranes isolated from the DDC-treated leaves resolved a novel chlorophyll-protein complex, which was identified as the light-harvesting complex I (LHC I)-deficient PS I complex when examined by 77 K fluorescence spectroscopy and two-dimensional sodium dodecyl sulfate gel electrophoresis. The possible dissociation of LHC I as an early structural change in the PS I complex after DDC-induced photoinhibition of PS I is discussed.
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Affiliation(s)
- Hong Jin Hwang
- Department of Molecular Biology, Pusan National University, Busan 609-735, South Korea
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Rinalducci S, Pedersen JZ, Zolla L. Formation of radicals from singlet oxygen produced during photoinhibition of isolated light-harvesting proteins of photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2004; 1608:63-73. [PMID: 14741586 DOI: 10.1016/j.bbabio.2003.10.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Electron spin resonance spectroscopy and liquid chromatography have been used to detect radical formation and fragmentation of polypeptides during photoinhibition of purified major antenna proteins, free of protease contaminants. In the absence of oxygen and light, no radicals were observed and there was no damage to the proteins. Similarly illumination of the apoproteins did not induce any polypeptide fragmentation, suggesting that chlorophyll, light and atmospheric oxygen are all participating in antenna degradation. The use of TEMP and DMPO as spin traps showed that protein damage initiates with generation of (1)O(2), presumably from a triplet chlorophyll, acting as a Type II photosensitizer which attacks directly the amino acids causing a complete degradation of protein into small fragments, without the contribution of proteases. Through the use of scavengers, it was shown that superoxide and H(2)O(2) were not involved initially in the reaction mechanism. A higher production of radicals was observed in trimers than in monomeric antenna, while radical production is strongly reduced when antennae were organized in the photosystem II (PSII) complex. Thus, monomerization of antennae as well as their incorporation into the PSII complex seem to represent physiologically protected forms. A comparison is made of the photoinhibition mechanisms of different photosynthetic systems.
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Affiliation(s)
- Sara Rinalducci
- Department of Environmental Sciences, University of Tuscia, Largo dell'Università, 01100 Viterbo, Italy
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Rajagopal S, Bukhov NG, Carpentier R. Photoinhibitory light-induced changes in the composition of chlorophyll-protein complexes and photochemical activity in photosystem-I submembrane fractions. Photochem Photobiol 2003; 77:284-91. [PMID: 12685656 DOI: 10.1562/0031-8655(2003)077<0284:plicit>2.0.co;2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effects of irradiation on photosystem (PS)-I submembrane particles using intense white light (2000 micoE x m(-2) x S(-1)) at chilling temperature (4 degrees C) were studied. PSI-dependent oxygen uptake activity was stable during the first 3 h of photoinhibitory illumination in the presence of added superoxide dismutase (SOD). Without added SOD, the oxygen uptake almost doubled during this period, presumably due to the denaturation of native membrane-bound SOD or its release from the PSI membranes. The total chlorophyll (Chl) content and the magnitude of light-induced absorbance changes at 830 nm (deltaA830) were also barely affected during the first 3-3.5 h of photoinhibitory treatment. However, further exposure to strong light markedly accelerated Chl breakdown followed by a decline in oxygen uptake rate and deltaA830. This corresponded with the disappearance of the bands attributed to PsaA/B polypeptides on electrophoretic gels. Despite the invariant maximum magnitude of deltaA830 during the first 3-3.5 h of photoinhibitory treatment, the light-response curves of P700 oxidation gradually altered, demonstrating a several-fold increase in the ability of weak actinic light to oxidize P700. The major Chl a-protein 1 (CP1) band gradually disappeared during the first 4 h of light exposure with a corresponding increase in the Chl content of a band with lower electrophoretic mobility ascribed to the formation of oligomers containing CP1, light-harvesting complex I (LHCI)-680 and LHCI-730. This aggregation of Chl-protein complexes, likely caused by photoinhibitory-induced cross-linking favoring light harvesting, is proposed to explain the enhanced capacity of weak light to oxidize P700 in photoinhibited PSI submembrane fractions compared with untreated ones.
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Affiliation(s)
- Subramanyam Rajagopal
- Groupe de Recherche en Energie et Information Biomoléculaires, Université du Québec a Trois-Riviéres, Québec, Canada
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29
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Velitchkova M, Yruela I, Alfonso M, Alonso PJ, Picorel R. Different kinetics of photoinactivation of photosystem I-mediated electron transport and P700 in isolated thylakoid membranes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2003; 69:41-8. [PMID: 12547495 DOI: 10.1016/s1011-1344(02)00404-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Photoinactivation kinetics of photosystem I (PSI)-mediated electron transport rate was compared to that of P700 content at room (22 degrees C) and low (4 degrees C) temperatures in isolated spinach thylakoid membranes. The high light treatment was carried out under aerobic and anaerobic conditions. At 22 degrees C the decrease of electron transport rate showed first order exponential kinetics. The amount of P700 decreased linearly, being less affected in the first hours of illumination. During photoinhibition at 4 degrees C in the presence of oxygen, the kinetics of inactivation of PSI photochemical activity and the content of P700 were different. It was found that 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) had different protective effect on the electron transport rate and on P700 content at both temperatures. Treatment with high light intensity under N(2) atmosphere had no effect on the electron transport rate or P700 content. The possible degradation of PSI reaction centre proteins was determined using immunoblot methods. In the presence of linear electron transport at 22 degrees C correlation between formation of toxic hydroxyl radicals and inhibition of oxygen uptake was observed.
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Affiliation(s)
- Maya Velitchkova
- Estación Experimental de Aula Dei, CSIC, Apdo. 202, 50080 Zaragoza, Spain.
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Häder DP, Lebert M, Sinha RP, Barbieri ES, Helbling EW. Role of protective and repair mechanisms in the inhibition of photosynthesis in marine macroalgae. Photochem Photobiol Sci 2002; 1:809-14. [PMID: 12656483 DOI: 10.1039/b206152j] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mechanism of photoinhibition was investigated in three representative macroalgal species growing on the coast of Patagonia: the chlorophyte Ulva rigida C. Agardh, the rhodophyte Porphyra columbina Montagne and the phaeophyte Dictyota dichotoma (Huds.) Lamour. Dark adapted specimens were exposed to 15 min unfiltered solar radiation to induce photoinhibition, and subsequently the recovery of the photosynthetic quantum yield was followed for up to 6 h. Photoinhibition is believed to be due to the damage and proteolysis of the D1 protein in the reaction center of Photosystem II. During recovery this protein is resynthesized. In order to prove this hypothesis, inhibitors of the chloroplast protein synthesis, streptomycin and chloramphenicol were applied. Both retarded the repair process indicating an inhibition of the D1 protein resynthesis during recovery after the damage they experienced during light exposure. Some algal groups use the xanthophyll cycle to ameliorate the inhibition by excessive light. Dithiothreitol, an inhibitor of violaxanthin de-epoxidase, was administered, to impair the xanthophyll cycle. It strongly affected both photoinhibition and recovery even in the red algal species, which do not have the xanthophyll cycle, indicating that this drug has significant side effects and should be used with caution for the study of the involvement of this protective cycle in algae. Pigmentation was followed in the three species using absorption spectroscopy of thallus extracts at 665 nm during continuous exposure to natural solar radiation or radiation deprived of the UV component during two days. The results indicated a pronounced variation in pigmentation over time due to bleaching and resynthesis. Solar radiation was monitored during the experiments in three channels (UV-B, UV-A and PAR) using an ELDONET instrument on site.
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Affiliation(s)
- Donat P Häder
- Institut für Botanik und Pharmazeutische Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, D-91058 Erlangen, Germany
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Rajagopal S, Bukhov N, Carpentier R. Changes in the structure of chlorophyll-protein complexes and excitation energy transfer during photoinhibitory treatment of isolated photosystem I submembrane particles. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2002; 67:194-200. [PMID: 12167319 DOI: 10.1016/s1011-1344(02)00326-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The activity of light-induced oxygen consumption, absorption spectra, low temperature (77 K) chlorophyll fluorescence emission and excitation spectra were studied in suspensions of photosystem (PS) I submembrane particles illuminated by 2000 microE m(-2) s(-1) strong white light (WL) at 4 degrees C. A significant stimulation of oxygen uptake was observed during the first 1-4 h of photoinhibitory treatment, which rapidly decreased during further light exposure. Chlorophyll (Chl) content gradually declined during the exposure of isolated PSI particles to strong light. In addition to the Chl photobleaching, pronounced changes were found in Chl absorption and fluorescence spectra. The position of the major peak in the red part of the absorption spectrum shifted from 680 nm towards shorter wavelengths in the course of strong light exposure. A 6-nm blue shift of that peak was observed after 5-h illumination. Even more pronounced changes were found in the characteristics of Chl fluorescence. The magnitude of the dominating long-wavelength emission band at 736 nm located in untreated particles was five times reduced after 2-h exposure, whereas the loss in absolute Chl contents did not exceed 10% of its initial value. The major peak in low-temperature Chl fluorescence emission spectra shifted from 736 to 721 nm after 6-h WL treatment. Individual Chl-protein complexes differed in the response of their absorption spectra to strong WL. Unlike light-harvesting complexes (LHC), LHCI-680 and LHC-730, which did not exhibit changes in the major peak position, its maximum was shifted from 678 to 671 nm in CPIa complex after PSI submembrane particles were irradiated with strong light for 6 h. The results demonstrated that excitation energy transfer represents the stage of photosynthetic utilization of absorbed quanta which is most sensitive to strong light in isolated PSI particles.
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Affiliation(s)
- S Rajagopal
- Groupe de Recherche en Energie et Information Biomoléculaires, Université du Québec à Trois-Rivières, CP 500 Trois-Rivières, Quebec, Canada G9A 5H7
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