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Laisk A, Peterson RB, Oja V. Excitation transfer and quenching in photosystem II, enlightened by carotenoid triplet state in leaves. PHOTOSYNTHESIS RESEARCH 2024; 160:31-44. [PMID: 38502255 DOI: 10.1007/s11120-024-01086-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 02/06/2024] [Indexed: 03/21/2024]
Abstract
Accumulation of carotenoid (Car) triplet states was investigated by singlet-triplet annihilation, measured as chlorophyll (Chl) fluorescence quenching in sunflower and lettuce leaves. The leaves were illuminated by Xe flashes of 4 μs length at half-height and 525-565 or 410-490 nm spectral band, maximum intensity 2 mol quanta m-2 s-1, flash photon dose up to 10 μmol m-2 or 4-10 PSII excitations. Superimposed upon the non-photochemically unquenched Fmd state, fluorescence was strongly quenched near the flash maximum (minimum yield Fe), but returned to the Fmd level after 30-50 μs. The fraction of PSII containing a 3Car in equilibrium with singlet excitation was calculated as Te = (Fmd-Fe)/Fmd. Light dependence of Te was a rectangular hyperbola, whose initial slope and plateau were determined by the quantum yields of triplet formation and annihilation and by the triplet lifetime. The intrinsic lifetime was 9 μs, but it was strongly shortened by the presence of O2. The triplet yield was 0.66 without nonphotochemical quenching (NPQ) but approached zero when NP-Quenched fluorescence approached 0.2 Fmd. The results show that in the Fmd state a light-adapted charge-separated PSIIL state is formed (Sipka et al., The Plant Cell 33:1286-1302, 2021) in which Pheo-P680+ radical pair formation is hindered, and excitation is terminated in the antenna by 3Car formation. The results confirm that there is no excitonic connectivity between PSII units. In the PSIIL state each PSII is individually turned into the NPQ state, where excess excitation is quenched in the antenna without 3Car formation.
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Affiliation(s)
- Agu Laisk
- Institute of Technology, University of Tartu, Nooruse St. 1, 50411, Tartu, Estonia.
| | - Richard B Peterson
- The Connecticut Agricultural Experiment Station, 123 Huntington St., New Haven, CT, 06511, USA
| | - Vello Oja
- Institute of Technology, University of Tartu, Nooruse St. 1, 50411, Tartu, Estonia
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Gates C, Ananyev G, Foflonker F, Bhattacharya D, Dismukes GC. Exceptional Quantum Efficiency Powers Biomass Production in Halotolerant Algae Picochlorum sp. . PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-024-01075-9. [PMID: 38329705 DOI: 10.1007/s11120-024-01075-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 01/04/2024] [Indexed: 02/09/2024]
Abstract
The green algal genus Picochlorum is of biotechnological interest because of its robust response to multiple environmental stresses. We compared the metabolic performance of P. SE3 and P. oklahomense to diverse microbial phototrophs and observed exceptional performance of photosystem II (PSII) in light energy conversion in both Picochlorum species. The quantum yield (QY) for O2 evolution is the highest of any phototroph yet observed, 32% (20%) by P. SE3 (P. okl) when normalized to total PSII subunit PsbA (D1) protein, and 80% (75%) normalized per active PSII, respectively. Three factors contribute: (1) an efficient water oxidizing complex (WOC) with the fewest photochemical misses of any organism; (2) faster reoxidation of reduced (PQH2)B in P. SE3 than in P. okl. (period-2 Fourier amplitude); and (3) rapid reoxidation of the plastoquinol pool by downstream electron carriers (Cyt b6f/PETC) that regenerates PQ faster in P. SE3. This performance gain is achieved without significant residue changes around the QB site and thus points to a pull mechanism involving faster PQH2 reoxidation by Cyt b6f/PETC that offsets charge recombination. This high flux in P. SE3 may be explained by genomically encoded plastoquinol terminal oxidases 1 and 2, whereas P. oklahomense has neither. Our results suggest two distinct types of PSII centers exist, one specializing in linear electron flow and the other in PSII-cyclic electron flow. Several amino acids within D1 differ from those in the low-light-descended D1 sequences conserved in Viridiplantae, and more closely match those in cyanobacterial high-light D1 isoforms, including changes near tyrosine Yz and a water/proton channel near the WOC. These residue changes may contribute to the exceptional performance of Picochlorum at high-light intensities by increasing the water oxidation efficiency and the electron/proton flux through the PSII acceptors (QAQB).
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Affiliation(s)
- Colin Gates
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Computational Biology and Molecular Biophysics Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, 60660, USA
| | - Gennady Ananyev
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
| | - Fatima Foflonker
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Biological Sciences, Clark Atlanta University, Atlanta, GA, 30314, USA
| | - Debashish Bhattacharya
- Department of Computational Biology and Molecular Biophysics Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
| | - G Charles Dismukes
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA.
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA.
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Lemke MD, Woodson JD. A genetic screen for dominant chloroplast reactive oxygen species signaling mutants reveals life stage-specific singlet oxygen signaling networks. FRONTIERS IN PLANT SCIENCE 2024; 14:1331346. [PMID: 38273946 PMCID: PMC10809407 DOI: 10.3389/fpls.2023.1331346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024]
Abstract
Introduction Plants employ intricate molecular mechanisms to respond to abiotic stresses, which often lead to the accumulation of reactive oxygen species (ROS) within organelles such as chloroplasts. Such ROS can produce stress signals that regulate cellular response mechanisms. One ROS, singlet oxygen (1O2), is predominantly produced in the chloroplast during photosynthesis and can trigger chloroplast degradation, programmed cell death (PCD), and retrograde (organelle-to-nucleus) signaling. However, little is known about the molecular mechanisms involved in these signaling pathways or how many different signaling 1O2 pathways may exist. Methods The Arabidopsis thaliana plastid ferrochelatase two (fc2) mutant conditionally accumulates chloroplast 1O2, making fc2 a valuable genetic system for studying chloroplast 1O2-initiated signaling. Here, we have used activation tagging in a new forward genetic screen to identify eight dominant fc2 activation-tagged (fas) mutations that suppress chloroplast 1O2-initiated PCD. Results While 1O2-triggered PCD is blocked in all fc2 fas mutants in the adult stage, such cellular degradation in the seedling stage is blocked in only two mutants. This differential blocking of PCD suggests that life-stage-specific 1O2-response pathways exist. In addition to PCD, fas mutations generally reduce 1O2-induced retrograde signals. Furthermore, fas mutants have enhanced tolerance to excess light, a natural mechanism to produce chloroplast 1O2. However, general abiotic stress tolerance was only observed in one fc2 fas mutant (fc2 fas2). Together, this suggests that plants can employ general stress tolerance mechanisms to overcome 1O2 production but that this screen was mostly specific to 1O2 signaling. We also observed that salicylic acid (SA) and jasmonate (JA) stress hormone response marker genes were induced in 1O2-stressed fc2 and generally reduced by fas mutations, suggesting that SA and JA signaling is correlated with active 1O2 signaling and PCD. Discussion Together, this work highlights the complexity of 1O2 signaling by demonstrating that multiple pathways may exist and introduces a suite of new 1O2 signaling mutants to investigate the mechanisms controlling chloroplast-initiated degradation, PCD, and retrograde signaling.
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Affiliation(s)
| | - Jesse D. Woodson
- The School of Plant Sciences, University of Arizona, Tucson, AZ, United States
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Cazzaniga S, Kim M, Pivato M, Perozeni F, Sardar S, D'Andrea C, Jin E, Ballottari M. Photosystem II monomeric antenna CP26 plays a key role in nonphotochemical quenching in Chlamydomonas. PLANT PHYSIOLOGY 2023; 193:1365-1380. [PMID: 37403662 DOI: 10.1093/plphys/kiad391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/17/2023] [Accepted: 06/06/2023] [Indexed: 07/06/2023]
Abstract
Thermal dissipation of excess excitation energy, called nonphotochemical quenching (NPQ), is 1 of the main photoprotective mechanisms in oxygenic photosynthetic organisms. Here, we investigated the function of the monomeric photosystem II (PSII) antenna protein CP26 in photoprotection and light harvesting in Chlamydomonas reinhardtii, a model organism for green algae. We used CRISPR/Cas9 genome editing and complementation to generate cp26 knockout mutants (named k6#) that did not negatively affect CP29 accumulation, which differed from previous cp26 mutants, allowing us to compare mutants specifically deprived of CP26, CP29, or both. The absence of CP26 partially affected PSII activity, causing reduced growth at low or medium light but not at high irradiances. However, the main phenotype observed in k6# mutants was a more than 70% reduction of NPQ compared to the wild type (Wt). This phenotype was fully rescued by genetic complementation and complemented strains accumulating different levels of CP26, demonstrating that ∼50% of CP26 content, compared to the Wt, was sufficient to restore the NPQ capacity. Our findings demonstrate a pivotal role for CP26 in NPQ induction, while CP29 is crucial for PSII activity. The genetic engineering of these 2 proteins could be a promising strategy to regulate the photosynthetic efficiency of microalgae under different light regimes.
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Affiliation(s)
- Stefano Cazzaniga
- Dipartimento di Biotecnologie, Università di Verona, Verona 37134, Italy
| | - Minjae Kim
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul 04763, South Korea
| | - Matteo Pivato
- Dipartimento di Biotecnologie, Università di Verona, Verona 37134, Italy
| | - Federico Perozeni
- Dipartimento di Biotecnologie, Università di Verona, Verona 37134, Italy
| | - Samim Sardar
- Istituto Italiano di Tecnologia, Center for Nano Science and Technology, Milano 20134, Italy
| | - Cosimo D'Andrea
- Istituto Italiano di Tecnologia, Center for Nano Science and Technology, Milano 20134, Italy
- Dipartimento di Fisica, Politecnico di Milano, Milano 20133, Italy
| | - EonSeon Jin
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul 04763, South Korea
| | - Matteo Ballottari
- Dipartimento di Biotecnologie, Università di Verona, Verona 37134, Italy
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Bhattacharjee S, Neese F, Pantazis DA. Triplet states in the reaction center of Photosystem II. Chem Sci 2023; 14:9503-9516. [PMID: 37712047 PMCID: PMC10498673 DOI: 10.1039/d3sc02985a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 08/16/2023] [Indexed: 09/16/2023] Open
Abstract
In oxygenic photosynthesis sunlight is harvested and funneled as excitation energy into the reaction center (RC) of Photosystem II (PSII), the site of primary charge separation that initiates the photosynthetic electron transfer chain. The chlorophyll ChlD1 pigment of the RC is the primary electron donor, forming a charge-separated radical pair with the vicinal pheophytin PheoD1 (ChlD1+PheoD1-). To avert charge recombination, the electron is further transferred to plastoquinone QA, whereas the hole relaxes to a central pair of chlorophylls (PD1PD2), subsequently driving water oxidation. Spin-triplet states can form within the RC when forward electron transfer is inhibited or back reactions are favored. This can lead to formation of singlet dioxygen, with potential deleterious effects. Here we investigate the nature and properties of triplet states within the PSII RC using a multiscale quantum-mechanics/molecular-mechanics (QM/MM) approach. The low-energy spectrum of excited singlet and triplet states, of both local and charge-transfer nature, is compared using range-separated time-dependent density functional theory (TD-DFT). We further compute electron paramagnetic resonance properties (zero-field splitting parameters and hyperfine coupling constants) of relaxed triplet states and compare them with available experimental data. Moreover, the electrostatic modulation of excited state energetics and redox properties of RC pigments by the semiquinone QA- is described. The results provide a detailed electronic-level understanding of triplet states within the PSII RC and form a refined basis for discussing primary and secondary electron transfer, charge recombination pathways, and possible photoprotection mechanisms in PSII.
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Affiliation(s)
- Sinjini Bhattacharjee
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
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Mohammad Aslam S, Vass I, Szabó M. Characterization of the Flash-Induced Fluorescence Wave Phenomenon in the Coral Endosymbiont Algae, Symbiodiniaceae. Int J Mol Sci 2023; 24:ijms24108712. [PMID: 37240058 DOI: 10.3390/ijms24108712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
The dinoflagellate algae, Symbiodiniaceae, are significant symbiotic partners of corals due to their photosynthetic capacity. The photosynthetic processes of the microalgae consist of linear electron transport, which provides the energetic balance of ATP and NADPH production for CO2 fixation, and alternative electron transport pathways, including cyclic electron flow, which ensures the elevated ATP requirements under stress conditions. Flash-induced chlorophyll fluorescence relaxation is a non-invasive tool to assess the various electron transport pathways. A special case of fluorescence relaxation, the so-called wave phenomenon, was found to be associated with the activity of NAD(P)H dehydrogenase (NDH) in microalgae. We showed previously that the wave phenomenon existed in Symbiodiniaceae under acute heat stress and microaerobic conditions, however, the electron transport processes related to the wave phenomenon remained unknown. In this work, using various inhibitors, we show that (i) the linear electron transport has a crucial role in the formation of the wave, (ii) the inhibition of the donor side of Photosystem II did not induce the wave, whereas inhibition of the Calvin-Benson cycle accelerated it, (iii) the wave phenomenon was related to the operation of type II NDH (NDH-2). We therefore propose that the wave phenomenon is an important marker of the regulation of electron transport in Symbiodiniaceae.
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Affiliation(s)
- Sabit Mohammad Aslam
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, 6726 Szeged, Hungary
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, 6720 Szeged, Hungary
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, 6726 Szeged, Hungary
| | - Milán Szabó
- Institute of Plant Biology, Biological Research Centre, Eötvös Loránd Research Network, 6726 Szeged, Hungary
- Climate Change Cluster, University of Technology Sydney, Ultimo 2007, Australia
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7
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Hayase T, Shimada Y, Mitomi T, Nagao R, Noguchi T. Triplet Delocalization over the Reaction Center Chlorophylls in Photosystem II. J Phys Chem B 2023; 127:1758-1770. [PMID: 36809007 DOI: 10.1021/acs.jpcb.3c00139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The triplet state of chlorophyll formed by charge recombination in photosystem II (PSII) is a precursor of harmful singlet oxygen. Although main localization of the triplet state on the monomeric chlorophyll, ChlD1, at cryogenic temperatures has been suggested, how the triplet state is delocalized on other chlorophylls remains unclear. Here, we investigated the distribution of the triplet state of chlorophyll in PSII using light-induced Fourier transform infrared (FTIR) difference spectroscopy. Measurements of triplet-minus-singlet FTIR difference spectra with PSII core complexes from cyanobacterial mutants, D1-V157H, D2-V156H, D2-H197A, and D1-H198A, in which the interactions of the 131-keto C═O groups of the reaction center chlorophylls, PD1, PD2, ChlD1, and ChlD2, respectively, were perturbed, identified the 131-keto C═O bands of the individual chlorophylls and showed that the triplet state is delocalized over all of these chlorophylls. It is suggested that the triplet delocalization plays important roles in the photoprotection and photodamage mechanisms in PSII.
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Affiliation(s)
- Taichi Hayase
- Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Yuichiro Shimada
- Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Tatsuya Mitomi
- Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Ryo Nagao
- Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.,Faculty of Agriculture, Shizuoka University, Shizuoka 422-8529, Japan
| | - Takumi Noguchi
- Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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McClain AM, Cruz JA, Kramer DM, Sharkey TD. The time course of acclimation to the stress of triose phosphate use limitation. PLANT, CELL & ENVIRONMENT 2023; 46:64-75. [PMID: 36305484 PMCID: PMC10100259 DOI: 10.1111/pce.14476] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 10/21/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Triose phosphate utilisation (TPU) limits the maximum rate at which plants can photosynthesise. However, TPU is almost never found to be limiting photosynthesis under ambient conditions for plants. This, along with previous results showing adaptability of TPU at low temperature, suggest that TPU capacity is regulated to be just above the photosynthetic rate achievable under the prevailing conditions. A set of experiments were performed to study the adaptability of TPU capacity when plants are acclimated to elevated CO2 concentrations. Plants held at 1500 ppm CO2 were initially TPU limited. After 30 h they no longer exhibited TPU limitations but they did not elevate their TPU capacity. Instead, the maximum rates of carboxylation and electron transport declined. A timecourse of regulatory responses was established. A step increase of CO2 first caused PSI to be oxidised but after 40 s both PSI and PSII had excess electrons as a result of acceptor-side limitations. Electron flow to PSI slowed and the proton motive force increased. Eventually, non-photochemical quenching reduced electron flow sufficiently to balance the TPU limitation. Over several minutes rubisco deactivated contributing to regulation of metabolism to overcome the TPU limitation.
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Affiliation(s)
- Alan M. McClain
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Plant Biotechnology for Health and SustainabilityMichigan State UniversityEast LansingMichiganUSA
| | - Jeffrey A. Cruz
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
| | - David M. Kramer
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Thomas D. Sharkey
- Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMichiganUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMichiganUSA
- Plant Resilience InstituteMichigan State UniversityEast LansingMichiganUSA
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Sugo Y, Ishikita H. Proton-mediated photoprotection mechanism in photosystem II. FRONTIERS IN PLANT SCIENCE 2022; 13:934736. [PMID: 36161009 PMCID: PMC9490181 DOI: 10.3389/fpls.2022.934736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/08/2022] [Indexed: 06/16/2023]
Abstract
Photo-induced charge separation, which is terminated by electron transfer from the primary quinone QA to the secondary quinone QB, provides the driving force for O2 evolution in photosystem II (PSII). However, the backward charge recombination using the same electron-transfer pathway leads to the triplet chlorophyll formation, generating harmful singlet-oxygen species. Here, we investigated the molecular mechanism of proton-mediated QA ⋅- stabilization. Quantum mechanical/molecular mechanical (QM/MM) calculations show that in response to the loss of the bicarbonate ligand, a low-barrier H-bond forms between D2-His214 and QA ⋅-. The migration of the proton from D2-His214 toward QA ⋅- stabilizes QA ⋅-. The release of the bicarbonate ligand from the binding Fe2+ site is an energetically uphill process, whereas the bidentate-to-monodentate reorientation is almost isoenergetic. These suggest that the bicarbonate protonation and decomposition may be a basis of the mechanism of photoprotection via QA ⋅-/QAH⋅ stabilization, increasing the QA redox potential and activating a charge-recombination pathway that does not generate the harmful singlet oxygen.
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Affiliation(s)
- Yu Sugo
- Department of Applied Chemistry, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Ishikita
- Department of Applied Chemistry, The University of Tokyo, Tokyo, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
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Semi-continuous cultivation strategy for improving the growth of Synechocystis sp. PCC 6803 based on the growth model of volume average light intensity. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Systemic Signaling: A Role in Propelling Crop Yield. PLANTS 2022; 11:plants11111400. [PMID: 35684173 PMCID: PMC9182853 DOI: 10.3390/plants11111400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/21/2022] [Accepted: 05/24/2022] [Indexed: 11/17/2022]
Abstract
Food security has become a topic of great concern in many countries. Global food security depends heavily on agriculture that has access to proper resources and best practices to generate higher crop yields. Crops, as with other plants, have a variety of strategies to adapt their growth to external environments and internal needs. In plants, the distal organs are interconnected through the vascular system and intricate hierarchical signaling networks, to communicate and enhance survival within fluctuating environments. Photosynthesis and carbon allocation are fundamental to crop production and agricultural outputs. Despite tremendous progress achieved by analyzing local responses to environmental cues, and bioengineering of critical enzymatic processes, little is known about the regulatory mechanisms underlying carbon assimilation, allocation, and utilization. This review provides insights into vascular-based systemic regulation of photosynthesis and resource allocation, thereby opening the way for the engineering of source and sink activities to optimize the yield performance of major crops.
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Iwasaki K, Szabó M, Tamburic B, Evenhuis C, Zavafer A, Kuzhiumparambil U, Ralph P. Investigating the impact of light quality on macromolecular composition of Chaetoceros muelleri. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:421-431. [PMID: 34635201 DOI: 10.1071/fp20337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/28/2021] [Indexed: 05/23/2023]
Abstract
Diatoms (Bacillariophyceae) are important to primary productivity of aquatic ecosystems. This algal group is also a valuable source of high value compounds that are utilised as aquaculture feed. The productivity of diatoms is strongly driven by light and CO2 availability, and macro- and micronutrient concentrations. The light dependency of biomass productivity and metabolite composition is well researched in diatoms, but information on the impact of light quality, particularly the productivity return on energy invested when using different monochromatic light sources, remains scarce. In this work, the productivity return on energy invested of improving growth rate, photosynthetic activity, and metabolite productivity of the diatom Chaetoceros muelleri under defined wavelengths (blue, red, and green) as well as while light is analysed. By adjusting the different light qualities to equal photosynthetically utilisable radiation, it was found that the growth rate and photosynthetic oxygen evolution was unchanged under white, blue, and green light, but it was lower under red light. Blue light improved the productivity return on energy invested for biomass, total protein, total lipid, total carbohydrate, and in fatty acids production, which would suggest that blue light should be used for aquaculture feed production.
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Affiliation(s)
- Kenji Iwasaki
- Climate Change Cluster (C3), Faculty of Science, University of Technology Sydney, NSW, Australia
| | - Milán Szabó
- Climate Change Cluster (C3), Faculty of Science, University of Technology Sydney, NSW, Australia; and Institute of Plant Biology, Biological Research Centre, Hungary, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
| | - Bojan Tamburic
- Water Research Centre, School of Civil and Environmental Engineering, UNSW, Sydney, NSW, Australia
| | - Christian Evenhuis
- Climate Change Cluster (C3), Faculty of Science, University of Technology Sydney, NSW, Australia
| | - Alonso Zavafer
- Climate Change Cluster (C3), Faculty of Science, University of Technology Sydney, NSW, Australia; and Research School of Biology, Australian National University, Canberra, ACT, Australia
| | | | - Peter Ralph
- Climate Change Cluster (C3), Faculty of Science, University of Technology Sydney, NSW, Australia
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Patil PP, Mohammad Aslam S, Vass I, Szabó M. Characterization of the wave phenomenon of flash-induced chlorophyll fluorescence in Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2022; 152:235-244. [PMID: 35166999 PMCID: PMC9424139 DOI: 10.1007/s11120-022-00900-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/25/2022] [Indexed: 06/01/2023]
Abstract
Flash-induced chlorophyll fluorescence relaxation is a powerful tool to monitor the reoxidation reactions of the reduced primary quinone acceptor, QA- by QB and the plastoquinone (PQ) pool, as well as the charge recombination reactions between the donor and acceptor side components of Photosystem II (PSII). Under certain conditions, when the PQ pool is highly reduced (e.g. in microaerobic conditions), a wave phenomenon appears in the fluorescence relaxation kinetics, which reflects the transient reoxidation and re-reduction of QA- by various electron transfer processes, which in cyanobacteria is mediated by NAD(P)H dehydrogenase (NDH-1). The wave phenomenon was also observed and assigned to the operation of type 2 NAD(P)H dehydrogenase (NDH-2) in the green alga Chlamydomonas reinhardtii under hydrogen-producing conditions, which required a long incubation of algae under sulphur deprivation (Krishna et al. J Exp Bot 70 (21):6321-6336, 2019). However, the conditions that induce the wave remained largely uncharacterized so far in microalgae. In this work, we investigated the wave phenomenon in Chlamydomonas reinhardtii under conditions that lead to a decrease of PSII activity by applying hydroxylamine treatment, which impacts the donor side of PSII in combination with a strongly reducing environment of the PQ pool (microaerobic conditions). A similar wave phenomenon could be induced by photoinhibitory conditions (illumination with strong light in the presence of the protein synthesis inhibitor lincomycin). These results indicate that the fluorescence wave phenomenon is activated in green algae when the PSII activity decreases relative to Photosystem I (PS I) activity and the PQ pool is strongly reduced. Therefore, the fluorescence wave could be used as a sensitive indicator of altered intersystem electron transfer processes, e.g. under stress conditions.
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Affiliation(s)
- Priyanka Pradeep Patil
- Biological Research Centre, Institute of Plant Biology, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
| | - Sabit Mohammad Aslam
- Biological Research Centre, Institute of Plant Biology, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Imre Vass
- Biological Research Centre, Institute of Plant Biology, Eötvös Loránd Research Network (ELKH), Szeged, Hungary.
| | - Milán Szabó
- Biological Research Centre, Institute of Plant Biology, Eötvös Loránd Research Network (ELKH), Szeged, Hungary.
- Climate Change Cluster, University of Technology Sydney, Ultimo, Australia.
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14
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Advances in the Understanding of the Lifecycle of Photosystem II. Microorganisms 2022; 10:microorganisms10050836. [PMID: 35630282 PMCID: PMC9145668 DOI: 10.3390/microorganisms10050836] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/14/2022] [Accepted: 04/16/2022] [Indexed: 02/04/2023] Open
Abstract
Photosystem II is a light-driven water-plastoquinone oxidoreductase present in cyanobacteria, algae and plants. It produces molecular oxygen and protons to drive ATP synthesis, fueling life on Earth. As a multi-subunit membrane-protein-pigment complex, Photosystem II undergoes a dynamic cycle of synthesis, damage, and repair known as the Photosystem II lifecycle, to maintain a high level of photosynthetic activity at the cellular level. Cyanobacteria, oxygenic photosynthetic bacteria, are frequently used as model organisms to study oxygenic photosynthetic processes due to their ease of growth and genetic manipulation. The cyanobacterial PSII structure and function have been well-characterized, but its lifecycle is under active investigation. In this review, advances in studying the lifecycle of Photosystem II in cyanobacteria will be discussed, with a particular emphasis on new structural findings enabled by cryo-electron microscopy. These structural findings complement a rich and growing body of biochemical and molecular biology research into Photosystem II assembly and repair.
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15
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Gisriel CJ, Shen G, Ho MY, Kurashov V, Flesher DA, Wang J, Armstrong WH, Golbeck JH, Gunner MR, Vinyard DJ, Debus RJ, Brudvig GW, Bryant DA. Structure of a monomeric photosystem II core complex from a cyanobacterium acclimated to far-red light reveals the functions of chlorophylls d and f. J Biol Chem 2022; 298:101424. [PMID: 34801554 PMCID: PMC8689208 DOI: 10.1016/j.jbc.2021.101424] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 11/26/2022] Open
Abstract
Far-red light (FRL) photoacclimation in cyanobacteria provides a selective growth advantage for some terrestrial cyanobacteria by expanding the range of photosynthetically active radiation to include far-red/near-infrared light (700-800 nm). During this photoacclimation process, photosystem II (PSII), the water:plastoquinone photooxidoreductase involved in oxygenic photosynthesis, is modified. The resulting FRL-PSII is comprised of FRL-specific core subunits and binds chlorophyll (Chl) d and Chl f molecules in place of several of the Chl a molecules found when cells are grown in visible light. These new Chls effectively lower the energy canonically thought to define the "red limit" for light required to drive photochemical catalysis of water oxidation. Changes to the architecture of FRL-PSII were previously unknown, and the positions of Chl d and Chl f molecules had only been proposed from indirect evidence. Here, we describe the 2.25 Å resolution cryo-EM structure of a monomeric FRL-PSII core complex from Synechococcus sp. PCC 7335 cells that were acclimated to FRL. We identify one Chl d molecule in the ChlD1 position of the electron transfer chain and four Chl f molecules in the core antenna. We also make observations that enhance our understanding of PSII biogenesis, especially on the acceptor side of the complex where a bicarbonate molecule is replaced by a glutamate side chain in the absence of the assembly factor Psb28. In conclusion, these results provide a structural basis for the lower energy limit required to drive water oxidation, which is the gateway for most solar energy utilization on earth.
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Affiliation(s)
| | - Gaozhong Shen
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Ming-Yang Ho
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA; Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania, USA; Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Vasily Kurashov
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - David A Flesher
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | | | - John H Golbeck
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Marilyn R Gunner
- Department of Physics, City College of New York, New York, New York, USA
| | - David J Vinyard
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Richard J Debus
- Department of Biochemistry, University of California, Riverside, California, USA
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA.
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA; Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania, USA.
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16
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Fleming ED, Bebout BM, Castenholz RW. Photochemical changes during rehydration of an intertidal cyanobacterial mat exposed to variations in salinity and light intensity. MICROBIOLOGY-SGM 2021; 167. [PMID: 34382926 DOI: 10.1099/mic.0.001075] [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: 11/18/2022]
Abstract
This study focuses on a Lyngbya cf. aestuarii dominated mat community from the intertidal zone of the Laguna Ojo de Liebre, Baja California Sur. In this environment, the mat is desiccated for several days between spring tides. While the mats were desiccated, photosynthetic activity was absent but recovered rapidly (~3 h) upon rehydration. It has been shown previously that the rate of photosynthetic recovery is dependent on both light intensity and salinity. In the current study, photosynthetic recovery was measured based on chlorophyll a fluorescence using pulse amplitude modulated (PAM) fluorometry. Upon the addition of water, photosystem II (PSII) complexes recovered the capacity for reaction centre excitation. However, these functional centres were initially closed. Respiratory activity early in recovery probably reduced the plastoquinone pool through the shared use of part of the photosynthetic transport chain, thus temporarily blocking electron transport downstream of PSII. The time that PSII complexes remained closed increased with light intensities above saturation. This condition is potentially damaging to the cyanobacteria since the exposure of closed PSII centres to high light intensities can lead to the production of singlet oxygen. After this initial lag period, PSII centres opened rapidly indicating an increase in the flow of electrons from PSII to PSI. The rate of photosynthetic recovery appeared to be limited primarily by the relatively slow return of functional PSII. Photosynthetic recovery rates were slower in salinities greater than those that naturally occur in the intertidal zone.
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Affiliation(s)
- Erich D Fleming
- Center for Ecology and Evolution, University of Oregon, Eugene, Oregon 97403, USA
- Present address: California State University Channel Islands, Camarillo, California 93012, USA
| | - Brad M Bebout
- NASA Ames Research Center, Moffett Field, California 94035, USA
| | - Richard W Castenholz
- Center for Ecology and Evolution, University of Oregon, Eugene, Oregon 97403, USA
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17
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Zavafer A, Mancilla C. Concepts of photochemical damage of Photosystem II and the role of excessive excitation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C: PHOTOCHEMISTRY REVIEWS 2021. [DOI: 10.1016/j.jphotochemrev.2021.100421] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Wu S, Mi T, Zhen Y, Yu K, Wang F, Yu Z. A Rise in ROS and EPS Production: New Insights into the Trichodesmium erythraeum Response to Ocean Acidification. JOURNAL OF PHYCOLOGY 2021; 57:172-182. [PMID: 32975309 DOI: 10.1111/jpy.13075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 08/20/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
The diazotrophic cyanobacterium Trichodesmium is thought to be a major contributor to the new N in parts of the oligotrophic, subtropical, and tropical oceans. In this study, physiological and biochemical methods and transcriptome sequencing were used to investigate the influences of ocean acidification (OA) on Trichodesmium erythraeum (T. erythraeum). We presented evidence that OA caused by CO2 slowed the growth rate and physiological activity of T. erythraeum. OA led to reduced development of proportion of the vegetative cells into diazocytes which included up-regulated genes of nitrogen fixation. Reactive oxygen species (ROS) accumulation was increased due to the disruption of photosynthetic electron transport and decrease in antioxidant enzyme activities under acidified conditions. This study showed that OA increased the amounts of (exopolysaccharides) EPS in T. erythraeum, and the key genes of ribose-5-phosphate (R5P) and glycosyltransferases (Tery_3818) were up-regulated. These results provide new insight into how ROS and EPS of T. erythraeum increase in an acidified future ocean to cope with OA-imposed stress.
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Affiliation(s)
- Shijie Wu
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Tiezhu Mi
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Yu Zhen
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Kaiqiang Yu
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Fuwen Wang
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Zhigang Yu
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education/Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266100, China
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Wilson S, Ruban AV. Rethinking the Influence of Chloroplast Movements on Non-photochemical Quenching and Photoprotection. PLANT PHYSIOLOGY 2020; 183:1213-1223. [PMID: 32404415 PMCID: PMC7333707 DOI: 10.1104/pp.20.00549] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 05/04/2020] [Indexed: 05/25/2023]
Abstract
Under blue light, plant chloroplasts relocate to different areas of the cell. The photoreceptor phototropin2 (phot2) mediates the chloroplast movement mechanism under excess blue light alongside the chloroplast unusual positioning1 (chup1) protein. Recently, it has been proposed that leaf transmittance changes associated with chloroplast relocation affect measurements of nonphotochemical quenching (NPQ), resulting in kinetic differences due to these movements (termed "qM"). We evaluated these claims using Arabidopsis (Arabidopsis thaliana) knock-out mutants lacking either phot2 or chup1 and analyzed the kinetics of both the onset and recovery of NPQ under equivalent intensities of both red and blue light. We also evaluated the photoprotective ability of chloroplast movements both during the early onset of photoinhibition and under sustained excess light. We monitored photoinhibition using the chlorophyll fluorescence parameter of photochemical quenching in the dark, which measures the redox state of QA within PSII without any of the complications of traditional F v /F m measurements. While there were noticeable differences between the responses under red and blue light, the chloroplast movement mechanism had no effect on the rate or amplitude of NPQ onset or recovery. Therefore, we were unable to replicate the "qM" component and its corresponding influence on the kinetics of NPQ in Arabidopsis grown under "shade" conditions. Furthermore, chloroplast relocation had no effect on the high-light tolerance of these plants. These data cast doubt upon the existence of a chloroplast movement-dependent component of NPQ Therefore, the influence of chloroplast movements on photoprotection should be thoroughly reevaluated.
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Affiliation(s)
- Sam Wilson
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, United Kingdom
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, United Kingdom
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20
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Cazzaniga S, Kim M, Bellamoli F, Jeong J, Lee S, Perozeni F, Pompa A, Jin E, Ballottari M. Photosystem II antenna complexes CP26 and CP29 are essential for nonphotochemical quenching in Chlamydomonas reinhardtii. PLANT, CELL & ENVIRONMENT 2020; 43:496-509. [PMID: 31724187 PMCID: PMC7004014 DOI: 10.1111/pce.13680] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/04/2019] [Indexed: 05/08/2023]
Abstract
Photosystems must balance between light harvesting to fuel the photosynthetic process for CO2 fixation and mitigating the risk of photodamage due to absorption of light energy in excess. Eukaryotic photosynthetic organisms evolved an array of pigment-binding proteins called light harvesting complexes constituting the external antenna system in the photosystems, where both light harvesting and activation of photoprotective mechanisms occur. In this work, the balancing role of CP29 and CP26 photosystem II antenna subunits was investigated in Chlamydomonas reinhardtii using CRISPR-Cas9 technology to obtain single and double mutants depleted of monomeric antennas. Absence of CP26 and CP29 impaired both photosynthetic efficiency and photoprotection: Excitation energy transfer from external antenna to reaction centre was reduced, and state transitions were completely impaired. Moreover, differently from higher plants, photosystem II monomeric antenna proteins resulted to be essential for photoprotective thermal dissipation of excitation energy by nonphotochemical quenching.
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Affiliation(s)
| | - Minjae Kim
- Department of Life ScienceHanyang UniversitySeoulSouth Korea
| | | | - Jooyoen Jeong
- Department of Life ScienceHanyang UniversitySeoulSouth Korea
| | - Sangmuk Lee
- Department of Life ScienceHanyang UniversitySeoulSouth Korea
| | | | - Andrea Pompa
- Dipartimento di Scienze BiomolecolariUniversità degli Studi di UrbinoUrbinoItaly
- Istituto di Bioscienze e BiorisorseConsiglio Nazionale delle RicerchePerugiaItaly
| | - EonSeon Jin
- Department of Life ScienceHanyang UniversitySeoulSouth Korea
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21
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Sun H, Zhang SB, Liu T, Huang W. Decreased photosystem II activity facilitates acclimation to fluctuating light in the understory plant Paris polyphylla. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1861:148135. [PMID: 31821793 DOI: 10.1016/j.bbabio.2019.148135] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 11/22/2019] [Accepted: 12/04/2019] [Indexed: 01/11/2023]
Abstract
In forests, understory plants are usually exposed to sunflecks on timescales of seconds or minutes. However, it is unclear how understory plants acclimate to fluctuating light. In this study, we compared chlorophyll fluorescence, PSI redox state and the electrochromic shift signal under fluctuating light between an understory plant Paris polyphylla (Liliaceae) and a light-demanding plant Bletilla striata (Orchidaceae). Within the first seconds after transition from low to high light, PSI was highly oxidized in P. polyphylla but was highly reduced in B. striata, although both species could not generate a sufficient trans-thylakoid proton gradient (ΔpH). Furthermore, the outflow of electrons from PSI to O2 was not significant in P. polyphylla, as indicated by the P700 redox kinetics upon dark-to-light transition. Therefore, the different responses of PSI to fluctuating light between P. polyphylla and B. striata could not be explained by ΔpH formation or alternative electron transport. In contrast, upon a sudden transition from low to high light, electron flow from PSII was much lower in P. polyphylla than in B. striata, suggesting that the rapid oxidation of PSI in P. polyphylla was largely attributed to the lower PSII activity. We propose, for the first time, that down-regulation of PSII activity is an important strategy used by some understory angiosperms to cope with sunflecks.
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Affiliation(s)
- Hu Sun
- Kunming Institute of Botany, Chinese Academy of Sciences, 650201 Kunming, China; University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, 650201 Kunming, China
| | - Tao Liu
- National Local Joint Engineering Research Center on Germplasm Utilization and Innovation of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, 650201 Kunming, China.
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, 650201 Kunming, China.
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22
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Tränkner M, Jamali Jaghdani S. Minimum magnesium concentrations for photosynthetic efficiency in wheat and sunflower seedlings. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 144:234-243. [PMID: 31590092 DOI: 10.1016/j.plaphy.2019.09.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/23/2019] [Accepted: 09/23/2019] [Indexed: 05/27/2023]
Abstract
Photosynthetic processes in the chloroplast depend on the abundance of magnesium (Mg) in relatively high amounts; hence chloroplasts might react more sensitive to Mg-deficiency than other physiological processes within other organelles. Most authors suggest a critical Mg concentration to be 1.5 mg g-1 DM for biomass and yield formation. However, it is not yet elucidated whether this value also applies to photosynthetic processes. The present study focused on the response of photosynthetic processes to different Mg tissue concentrations. Wheat (Triticum aestivum) and sunflower (Helianthus annuus) plants were grown hydroponically for 10 days with 8 different levels of Mg supply (1.0, 0.5, 0.25, 0.1, 0.075, 0.05, 0.025, 0.01 mM Mg). Specific leaf mass, SPAD values, assimilation rate, Fv/Fm, electron transport rate and photochemical and non-photochemical quenching parameters were determined on youngest mature leaves. Tissue Mg concentrations decreased with lowering Mg supply to lowest concentrations of 0.7 mg g-1 DM in wheat leaves, but photosynthetic capacity was not affected. In sunflower leaves, lowest Mg concentrations of 0.56 mg g-1 DM were achieved and a diminished photosynthetic capacity was observed. The study shows that a Mg tissue concentration of 1.5 mg g-1 DM did not induce a negative effect on the photosynthetic capacity of wheat and sunflower leaves under our experimental conditions and hence, the critical Mg concentration for photosynthetic processes might be lower than for biomass and yield formation.
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Affiliation(s)
- Merle Tränkner
- Institute of Applied Plant Nutrition (IAPN), Georg-August University Goettingen, 37075, Goettingen, Germany.
| | - Setareh Jamali Jaghdani
- Institute of Applied Plant Nutrition (IAPN), Georg-August University Goettingen, 37075, Goettingen, Germany
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23
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Agostini A, Dal Farra MG, Paulsen H, Polimeno A, Orian L, Di Valentin M, Carbonera D. Similarity and Specificity of Chlorophyll b Triplet State in Comparison to Chlorophyll a as Revealed by EPR/ENDOR and DFT Calculations. J Phys Chem B 2019; 123:8232-8239. [DOI: 10.1021/acs.jpcb.9b07912] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Alessandro Agostini
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
- Institute of Molecular Physiology, Johannes Gutenberg University, Johannes-von-Müller-Weg 6, 55128 Mainz, Germany
| | - Maria Giulia Dal Farra
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Harald Paulsen
- Institute of Molecular Physiology, Johannes Gutenberg University, Johannes-von-Müller-Weg 6, 55128 Mainz, Germany
| | - Antonino Polimeno
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Laura Orian
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Marilena Di Valentin
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Donatella Carbonera
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
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A thylakoid membrane-bound and redox-active rubredoxin (RBD1) functions in de novo assembly and repair of photosystem II. Proc Natl Acad Sci U S A 2019; 116:16631-16640. [PMID: 31358635 PMCID: PMC6697814 DOI: 10.1073/pnas.1903314116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Photosystem II (PSII) catalyzes the light-driven oxidation of water in photosynthesis, supplying energy and oxygen to many life-forms on earth. During PSII assembly and repair, PSII intermediate complexes are prone to photooxidative damage, requiring mechanisms to minimize this damage. Here, we report the functional characterization of RBD1, a PSII assembly factor that interacts with PSII intermediate complexes to ensure their functional assembly and repair. We propose that the redox activity of RBD1 participates together with the cytochrome b559 to protect PSII from photooxidation. This work not only improves our understanding of cellular protection mechanisms for the vital PSII complex but also informs genetic engineering strategies for protection of PSII repair to increase agricultural productivity. Photosystem II (PSII) undergoes frequent photooxidative damage that, if not repaired, impairs photosynthetic activity and growth. How photosynthetic organisms protect vulnerable PSII intermediate complexes during de novo assembly and repair remains poorly understood. Here, we report the genetic and biochemical characterization of chloroplast-located rubredoxin 1 (RBD1), a PSII assembly factor containing a redox-active rubredoxin domain and a single C-terminal transmembrane α-helix (TMH) domain. RBD1 is an integral thylakoid membrane protein that is enriched in stroma lamellae fractions with the rubredoxin domain exposed on the stromal side. RBD1 also interacts with PSII intermediate complexes containing cytochrome b559. Complementation of the Chlamydomonas reinhardtii (hereafter Chlamydomonas) RBD1-deficient 2pac mutant with constructs encoding RBD1 protein truncations and site-directed mutations demonstrated that the TMH domain is essential for de novo PSII assembly, whereas the rubredoxin domain is involved in PSII repair. The rubredoxin domain exhibits a redox midpoint potential of +114 mV and is proficient in 1-electron transfers to a surrogate cytochrome c in vitro. Reduction of oxidized RBD1 is NADPH dependent and can be mediated by ferredoxin-NADP+ reductase (FNR) in vitro. We propose that RBD1 participates, together with the cytochrome b559, in the protection of PSII intermediate complexes from photooxidative damage during de novo assembly and repair. This role of RBD1 is consistent with its evolutionary conservation among photosynthetic organisms and the fact that it is essential in photosynthetic eukaryotes.
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25
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Quantitative assessment of the high-light tolerance in plants with an impaired photosystem II donor side. Biochem J 2019; 476:1377-1386. [PMID: 31036714 DOI: 10.1042/bcj20190208] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/24/2019] [Accepted: 04/29/2019] [Indexed: 01/15/2023]
Abstract
Photoinhibition is the light-induced down-regulation of photosynthetic efficiency, the primary target of which is photosystem II (PSII). Currently, there is no clear consensus on the exact mechanism of this process. However, it is clear that inhibition can occur through limitations on both the acceptor- and donor side of PSII. The former mechanism is caused by electron transport limitations at the PSII acceptor side. Whilst, the latter mechanism relies on the disruption of the oxygen-evolving complex. Both of these mechanisms damage the PSII reaction centre (RC). Using a novel chlorophyll fluorescence methodology, RC photoinactivation can be sensitively measured and quantified alongside photoprotection in vivo This is achieved through estimation of the redox state of Q A, using the parameter of photochemical quenching in the dark (qPd). This study shows that through the use of PSII donor-side inhibitors, such as UV-B and Cd2+, there is a steeper gradient of photoinactivation in the systems with a weakened donor side, independent of the level of NPQ attained. This is coupled with a concomitant decline in the light tolerance of PSII. The native light tolerance is partially restored upon the use of 1,5-diphenylcarbazide (DPC), a PSII electron donor, allowing for the balance between the inhibitory pathways to be sensitively quantified. Thus, this study confirms that the impact of donor-side inhibition can be detected alongside acceptor-side photoinhibition using the qPd parameter and confirms qPd as a valid, sensitive and unambiguous parameter to sensitively quantify the onset of photoinhibition through both acceptor- or donor-side mechanisms.
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Yang YW, Yin YC, Li ZK, Huang D, Shang JL, Chen M, Qiu BS. Orange and red carotenoid proteins are involved in the adaptation of the terrestrial cyanobacterium Nostoc flagelliforme to desiccation. PHOTOSYNTHESIS RESEARCH 2019; 140:103-113. [PMID: 30826949 DOI: 10.1007/s11120-019-00629-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
The remarkable drought-resistance of the terrestrial cyanobacterium Nostoc flagelliforme (N. flagelliforme) has attracted attention for many years. In this study, we purified a group of red proteins that accumulate in dried field samples of N. flagelliforme. These red proteins contain canthaxanthin as the bound chromophore. Native-PAGE analysis revealed that the purified red proteins resolved into six visible red bands and were composed of four helical carotenoid proteins (HCPs), HCP1, HCP2, HCP3, and HCP6 (homologs to the N-terminal domain of the orange carotenoid protein (OCP)). Seven genes encode homologs of the OCP in the genome of N. flagelliforme: two full-length ocp genes (ocpx1 and ocpx2), four N-terminal domain hcp genes (hcp1, hcp2, hcp3, and hcp6), and one C-terminal domain ccp gene. The expression levels of hcp1, hcp2, and hcp6 were highly dependent on the water status of field N. flagelliforme samples, being downregulated during rehydration and upregulated during subsequent dehydration. Transcripts of ocpx2 were dominant in the dried field samples, which we confirmed by detecting the presence of OCPx2-derived peptides in the purified red proteins. The results shed light on the relationship between carotenoid-binding proteins and the desiccation resistance of terrestrial cyanobacteria, and the physiological functions of carotenoid-binding protein complexes in relation to desiccation are discussed.
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Affiliation(s)
- Yi-Wen Yang
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, People's Republic of China
| | - Yan-Chao Yin
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, People's Republic of China
| | - Zheng-Ke Li
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, People's Republic of China
| | - Da Huang
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, People's Republic of China
| | - Jin-Long Shang
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, People's Republic of China
| | - Min Chen
- ARC Centre of Excellence for Translational Photosynthesis & School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, 2006, Australia.
| | - Bao-Sheng Qiu
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, People's Republic of China.
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Wilson S, Ruban AV. Enhanced NPQ affects long-term acclimation in the spring ephemeral Berteroa incana. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1861:148014. [PMID: 30880080 DOI: 10.1016/j.bbabio.2019.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 02/08/2019] [Accepted: 03/10/2019] [Indexed: 12/25/2022]
Abstract
The spring ephemeral Berteroa incana is a familial relative of Arabidopsis thaliana and thrives in a diverse range of terrestrial ecosystems. Within this study, the novel chlorophyll fluorescence parameter of photochemical quenching in the dark (qPd) was used to measure the redox state of the primary quinone electron acceptor (QA) in order to estimate the openness of photosystem II (PSII) reaction centres (RC). From this, the early onset of photoinactivation can be sensitively quantified alongside the light tolerance of PSII and the photoprotective efficiency of nonphotochemical quenching (NPQ). This study shows that, with regards to A. thaliana, NPQ is enhanced in B. incana in both low-light (LL) and high-light (HL) acclimation states. Moreover, light tolerance is increased by up to 500%, the rate of photoinactivation is heavily diminished, and the ability to recover from light stress is enhanced in B. incana, relative to A. thaliana. This is due to faster synthesis of zeaxanthin and a larger xanthophyll cycle (XC) pool available for deepoxidation. Moreover, preferential energy transfer via CP47 around the RC further enhances efficient photoprotection. As a result, a high functional cross-section of photosystem II is maintained and is not downregulated when B. incana is acclimated to HL. A greater capacity for protective NPQ allows B. incana to maintain an enhanced light-harvesting capability when acclimated to a range of light conditions. This enhancement of flexible short-term protection saves the metabolic cost of long-term acclimatory changes.
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Affiliation(s)
- Sam Wilson
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
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High level of reactive oxygen species inhibits triacylglycerols accumulation in Chlamydomonas reinhardtii. ALGAL RES 2019. [DOI: 10.1016/j.algal.2018.101400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Dogra V, Kim C. Singlet Oxygen Metabolism: From Genesis to Signaling. FRONTIERS IN PLANT SCIENCE 2019; 10:1640. [PMID: 31969891 PMCID: PMC6960194 DOI: 10.3389/fpls.2019.01640] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/21/2019] [Indexed: 05/03/2023]
Abstract
Singlet oxygen (1O2) is an excited state of molecular oxygen with an electron spin shift in the molecular orbitals, which is extremely unstable and highly reactive. In plants, 1O2 is primarily generated as a byproduct of photosynthesis in the photosystem II reaction center (PSII RC) and the light-harvesting antenna complex (LHC) in the grana core (GC). This occurs upon the absorption of light energy when the excited chlorophyll molecules in the PSII transfer the excess energy to molecular oxygen, thereby generating 1O2. As a potent oxidant, 1O2 promotes oxidative damage. However, at sub-lethal levels, it initiates chloroplast-to-nucleus retrograde signaling to contribute to plant stress responses, including acclimation and cell death. The thylakoid membranes comprise two spatially separated 1O2 sensors: β-carotene localized in the PSII RC in the GC and the nuclear-encoded chloroplast protein EXECUTER1 (EX1) residing in the non-appressed grana margin (GM). Finding EX1 in the GM suggests the existence of an additional source of 1O2 in the GM and the presence of two distinct 1O2-signaling pathways. In this review, we mainly discuss the genesis and impact of 1O2 in plant physiology.
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Loss of Function in Zeaxanthin Epoxidase of Dunaliella tertiolecta Caused by a Single Amino Acid Mutation within the Substrate-Binding Site. Mar Drugs 2018; 16:md16110418. [PMID: 30388729 PMCID: PMC6266236 DOI: 10.3390/md16110418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 10/21/2018] [Accepted: 10/26/2018] [Indexed: 12/17/2022] Open
Abstract
The zea1 mutant of marine microalga Dunaliella tertiolecta accumulates zeaxanthin under normal growth conditions, and its phenotype has been speculated to be related to zeaxanthin epoxidase (ZEP). In this study, we isolated the ZEP gene from both wild-type D. tertiolecta and the mutant. We found that the zea1 mutant has a point mutation of the 1337th nucleotide of the ZEP sequence (a change from guanine to adenine), resulting in a change of glycine to aspartate in a highly conserved region in the catalytic domain. Similar expression levels of ZEP mRNA and protein in both wild-type and zea1 were confirmed by using qRT-PCR and western blot analysis, respectively. Additionally, the enzyme activity analysis of ZEPs in the presence of cofactors showed that the inactivation of ZEP in zea1 was not caused by deficiency in the levels of cofactors. From the predicted three-dimensional ZEP structure of zea1, we observed a conformational change on the substrate-binding site in the ZEP. A comparative analysis of the ZEP structures suggested that the conformational change induced by a single amino acid mutation might impact the interaction between the substrate and substrate-binding site, resulting in loss of zeaxanthin epoxidase function.
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Cordara A, Re A, Pagliano C, Van Alphen P, Pirone R, Saracco G, Branco Dos Santos F, Hellingwerf K, Vasile N. Analysis of the light intensity dependence of the growth of Synechocystis and of the light distribution in a photobioreactor energized by 635 nm light. PeerJ 2018; 6:e5256. [PMID: 30065870 PMCID: PMC6065478 DOI: 10.7717/peerj.5256] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/26/2018] [Indexed: 12/05/2022] Open
Abstract
Synechocystis gathered momentum in modelling studies and biotechnological applications owing to multiple factors like fast growth, ability to fix carbon dioxide into valuable products, and the relative ease of genetic manipulation. Synechocystis physiology and metabolism, and consequently, the productivity of Synechocystis-based photobioreactors (PBRs), are heavily light modulated. Here, we set up a turbidostat-controlled lab-scale cultivation system in order to study the influence of varying orange–red light intensities on Synechocystis growth characteristics and photosynthetic activity. Synechocystis growth and photosynthetic activity were found to raise as supplied light intensity increased up to 500 μmol photons m−2 s−1 and to enter the photoinhibition state only at 800 μmol photons m−2 s−1. Interestingly, reverting the light to a non-photo-inhibiting intensity unveiled Synechocystis to be able to promptly recover. Furthermore, our characterization displayed a clear correlation between variations in growth rate and cell size, extending a phenomenon previously observed in other cyanobacteria. Further, we applied a modelling approach to simulate the effects produced by varying the incident light intensity on its local distribution within the PBR vessel. Our model simulations suggested that the photosynthetic activity of Synechocystis could be enhanced by finely regulating the intensity of the light incident on the PBR in order to prevent cells from experiencing light-induced stress and induce their exploitation of areas of different local light intensity formed in the vessel. In the latter case, the heterogeneous distribution of the local light intensity would allow Synechocystis for an optimized usage of light.
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Affiliation(s)
- Alessandro Cordara
- Applied Science and Technology Department-Biosolar Lab, Politecnico di Torino, Turin, Italy.,Centre for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Turin, Italy
| | - Angela Re
- Centre for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Turin, Italy
| | - Cristina Pagliano
- Applied Science and Technology Department-Biosolar Lab, Politecnico di Torino, Turin, Italy
| | - Pascal Van Alphen
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Raffaele Pirone
- Applied Science and Technology Department, Politecnico di Torino, Turin, Italy
| | - Guido Saracco
- Centre for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Turin, Italy
| | | | - Klaas Hellingwerf
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Nicolò Vasile
- Centre for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Turin, Italy
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Pfündel EE, Latouche G, Meister A, Cerovic ZG. Linking chloroplast relocation to different responses of photosynthesis to blue and red radiation in low and high light-acclimated leaves of Arabidopsis thaliana (L.). PHOTOSYNTHESIS RESEARCH 2018; 137:105-128. [PMID: 29374806 DOI: 10.1007/s11120-018-0482-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 01/09/2018] [Indexed: 05/16/2023]
Abstract
Low light (LL) and high light (HL)-acclimated plants of A. thaliana were exposed to blue (BB) or red (RR) light or to a mixture of blue and red light (BR) of incrementally increasing intensities. The light response of photosystem II was measured by pulse amplitude-modulated chlorophyll fluorescence and that of photosystem I by near infrared difference spectroscopy. The LL but not HL leaves exhibited blue light-specific responses which were assigned to relocation of chloroplasts from the dark to the light-avoidance arrangement. Blue light (BB and BR) decreased the minimum fluorescence ([Formula: see text]) more than RR light. This extra reduction of the [Formula: see text] was stronger than theoretically predicted for [Formula: see text] quenching by energy dissipation but actual measurement and theory agreed in RR treatments. The extra [Formula: see text] reduction was assigned to decreased light absorption of chloroplasts in the avoidance position. A maximum reduction of 30% was calculated. Increasing intensities of blue light affected the fluorescence parameters NPQ and qP to a lesser degree than red light. After correcting for the optical effects of chloroplast relocation, the NPQ responded similarly to blue and red light. The same correction method diminished the color-specific variations in qP but did not abolish it; thus strongly indicating the presence of another blue light effect which also moderates excitation pressure in PSII but cannot be ascribed to absorption variations. Only after RR exposure, a post-illumination overshoot of [Formula: see text] and fast oxidation of PSI electron acceptors occurred, thus, suggesting an electron flow from stromal reductants to the plastoquinone pool.
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Affiliation(s)
- Erhard E Pfündel
- Lehrstuhl für Botanik II der Universität Würzburg, Julius-von-Sachs Institut für Biowissenschaften, 97082, Würzburg, Germany.
- Heinz Walz GmbH, Eichenring 6, 91090, Effeltrich, Germany.
| | - Gwendal Latouche
- Université Paris-Saclay, Université Paris-Sud, Laboratoire Écologie Systématique et Évolution, UMR8079, Bât. 362, 91405, Orsay, France
- CNRS, 91405, Orsay, France
- AgroParisTech, 75231, Paris, France
| | - Armin Meister
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstraße 3, 06466, Gatersleben, Germany
| | - Zoran G Cerovic
- Université Paris-Saclay, Université Paris-Sud, Laboratoire Écologie Systématique et Évolution, UMR8079, Bât. 362, 91405, Orsay, France
- CNRS, 91405, Orsay, France
- AgroParisTech, 75231, Paris, France
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33
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Townsend AJ, Ware MA, Ruban AV. Dynamic interplay between photodamage and photoprotection in photosystem II. PLANT, CELL & ENVIRONMENT 2018; 41:1098-1112. [PMID: 29210070 DOI: 10.1111/pce.13107] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/20/2017] [Accepted: 11/21/2017] [Indexed: 06/07/2023]
Abstract
Photoinhibition is the light-induced reduction in photosynthetic efficiency and is usually associated with damage to the D1 photosystem II (PSII) reaction centre protein. This damage must either be repaired, through the PSII repair cycle, or prevented in the first place by nonphotochemical quenching (NPQ). Both NPQ and D1 repair contribute to light tolerance because they ensure the long-term maintenance of the highest quantum yield of PSII. However, the relative contribution of each of these processes is yet to be elucidated. The application of a pulse amplitude modulation fluorescence methodology, called protective NPQ, enabled us to evaluate of the protective effectiveness of the processes. Within this study, the contribution of NPQ and D1 repair to the photoprotective capacity of Arabidopsis thaliana was elucidated by using inhibitors and mutants known to affect each process. We conclude that NPQ contributes a greater amount to the maintenance of a high PSII yield than D1 repair under short periods of illumination. This research further supports the role of protective components of NPQ during light fluctuations and the value of protective NPQ and qPd as unambiguous fluorescence parameters, as opposed to qI and Fv /Fm , for quantifying photoinactivation of reaction centre II and light tolerance of photosynthetic organisms.
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Affiliation(s)
- Alexandra J Townsend
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E14NS, UK
| | - Maxwell A Ware
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E14NS, UK
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E14NS, UK
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Nozawa Y, Noguchi T. pH-Dependent Regulation of the Relaxation Rate of the Radical Anion of the Secondary Quinone Electron Acceptor QB in Photosystem II As Revealed by Fourier Transform Infrared Spectroscopy. Biochemistry 2018; 57:2828-2836. [DOI: 10.1021/acs.biochem.8b00263] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yosuke Nozawa
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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The wavelength of the incident light determines the primary charge separation pathway in Photosystem II. Sci Rep 2018; 8:2837. [PMID: 29434283 PMCID: PMC5809461 DOI: 10.1038/s41598-018-21101-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 01/25/2018] [Indexed: 01/12/2023] Open
Abstract
Charge separation is a key component of the reactions cascade of photosynthesis, by which solar energy is converted to chemical energy. From this photochemical reaction, two radicals of opposite charge are formed, a highly reducing anion and a highly oxidising cation. We have previously proposed that the cation after far-red light excitation is located on a component different from PD1, which is the location of the primary electron hole after visible light excitation. Here, we attempt to provide further insight into the location of the primary charge separation upon far-red light excitation of PS II, using the EPR signal of the spin polarized 3P680 as a probe. We demonstrate that, under far-red light illumination, the spin polarized 3P680 is not formed, despite the primary charge separation still occurring at these conditions. We propose that this is because under far-red light excitation, the primary electron hole is localized on ChlD1, rather than on PD1. The fact that identical samples have demonstrated charge separation upon both far-red and visible light excitation supports our hypothesis that two pathways for primary charge separation exist in parallel in PS II reaction centres. These pathways are excited and activated dependent of the wavelength applied.
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36
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Ma L, Calfee BC, Morris JJ, Johnson ZI, Zinser ER. Degradation of hydrogen peroxide at the ocean's surface: the influence of the microbial community on the realized thermal niche of Prochlorococcus. THE ISME JOURNAL 2018; 12:473-484. [PMID: 29087377 PMCID: PMC5776462 DOI: 10.1038/ismej.2017.182] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 09/14/2017] [Accepted: 09/22/2017] [Indexed: 02/06/2023]
Abstract
Prochlorococcus, the smallest and most abundant phytoplankter in the ocean, is highly sensitive to hydrogen peroxide (HOOH), and co-occurring heterotrophs such as Alteromonas facilitate the growth of Prochlorococcus by scavenging HOOH. Temperature is also a major influence on Prochlorococcus abundance and distribution in the ocean, and studies in other photosynthetic organisms have shown that HOOH and temperature extremes can act together as synergistic stressors. To address potential synergistic effects of temperature and HOOH on Prochlorococcus growth, high- and low-temperature-adapted representative strains were cultured at ecologically relevant concentrations under a range of HOOH concentrations and temperatures. Higher concentrations of HOOH severely diminished the permissive temperature range for growth of both Prochlorococcus strains. At the permissive temperatures, the growth rates of both Prochlorococcus strains decreased as a function of HOOH, and cold temperature increased susceptibility of photosystem II to HOOH-mediated damage. Serving as a proxy for the natural community, co-cultured heterotrophic bacteria increased the Prochlorococcus growth rate under these temperatures, and expanded the permissive range of temperature for growth. These studies indicate that in the ocean, the cross-protective function of the microbial community may confer a fitness increase for Prochlorococcus at its temperature extremes, especially near the ocean surface where oxidative stress is highest. This interaction may play a substantial role in defining the realized thermal niche and habitat range of Prochlorococcus with respect to latitude.
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Affiliation(s)
- Lanying Ma
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Benjamin C Calfee
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - J Jeffrey Morris
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zackary I Johnson
- Nicholas School of the Environment and Biology Department, Duke University Marine Laboratory, Beaufort, NC, USA
| | - Erik R Zinser
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA.
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Murata N, Nishiyama Y. ATP is a driving force in the repair of photosystem II during photoinhibition. PLANT, CELL & ENVIRONMENT 2018; 41:285-299. [PMID: 29210214 DOI: 10.1111/pce.13108] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 05/15/2023]
Abstract
Repair of photosystem II (PSII) during photoinhibition involves replacement of photodamaged D1 protein by newly synthesized D1 protein. In this review, we summarize evidence for the indispensability of ATP in the degradation and synthesis of D1 during the repair of PSII. Synthesis of one molecule of the D1 protein consumes more than 1,300 molecules of ATP equivalents. The degradation of photodamaged D1 by FtsH protease also consumes approximately 240 molecules of ATP. In addition, ATP is required for several other aspects of the repair of PSII, such as transcription of psbA genes. These requirements for ATP during the repair of PSII have been demonstrated by experiments showing that the synthesis of D1 and the repair of PSII are interrupted by inhibitors of ATP synthase and uncouplers of ATP synthesis, as well as by mutation of components of ATP synthase. We discuss the contribution of cyclic electron transport around photosystem I to the repair of PSII. Furthermore, we introduce new terms relevant to the regulation of the PSII repair, namely, "ATP-dependent regulation" and "redox-dependent regulation," and we discuss the possible contribution of the ATP-dependent regulation of PSII repair under environmental stress.
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Affiliation(s)
- Norio Murata
- National Institute for Basic Biology, Okazaki, 444-8585, Japan
| | - Yoshitaka Nishiyama
- Department of Biochemistry and Molecular Biology and Institute for Environmental Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
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Remote Sensing of Coral Bleaching Using Temperature and Light: Progress towards an Operational Algorithm. REMOTE SENSING 2017. [DOI: 10.3390/rs10010018] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Havurinne V, Tyystjärvi E. Action Spectrum of Photoinhibition in the Diatom Phaeodactylum tricornutum. PLANT & CELL PHYSIOLOGY 2017; 58:2217-2225. [PMID: 29059446 DOI: 10.1093/pcp/pcx156] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 10/15/2017] [Indexed: 05/28/2023]
Abstract
Light-dependent electron transfer is necessary for photosynthesis, but light also damages PSII. Light-induced damage to PSII is called photoinhibition, and the damaging reactions of photoinhibition are still under debate. Diatoms possess an exotic combination of light-harvesting pigments, Chls a/c and fucoxanthin, making them an interesting platform for studying the photoreceptors of photoinhibition. We first confirmed the direct proportionality of photoinhibition to the photon flux density of incident light in the diatom Phaeodactylum tricornutum. Phaeodactylum is known for its efficient non-photochemical quenching, and the effect of this photoprotective mechanism on photoinhibition was tested. Photoinhibition proceeded essentially at the same rate in blue-light-grown Phaeodactylum cells that are capable of non-photochemical quenching and in red-light-grown, non-photochemical quenching-deficient cells. To obtain more insight into how the pigment composition of diatoms affects photoinhibition, we measured the action spectrum of photoinhibition in Phaeodactylum. In visible light, the action spectrum resembled the absorption spectrum of Phaeodactylum, and UV radiation caused much more photoinhibition than visible light. Comparison of the action spectrum of photoinhibition with the absorption spectrum and the excitation spectrum of 77 K PSII fluorescence emission confirmed that photosynthetic pigments are involved in photoinhibition, but the photoinhibitory efficiency of red light is weak, suggesting that the role of light-harvesting pigments as light receptors of photoinhibition is secondary. Finally, we compared photoinhibition in Phaeodactylum with that in other photosynthetic organisms, and our data indicate that the PSII reaction centers of Phaeodactylum are not particularly well protected against the primary damage of photoinhibition.
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Affiliation(s)
- Vesa Havurinne
- University of Turku, Department of Biochemistry/Molecular Plant Biology, 20014 Turku, Finland
| | - Esa Tyystjärvi
- University of Turku, Department of Biochemistry/Molecular Plant Biology, 20014 Turku, Finland
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Venkanna D, Südfeld C, Baier T, Homburg SV, Patel AV, Wobbe L, Kruse O. Knock-Down of the IFR1 Protein Perturbs the Homeostasis of Reactive Electrophile Species and Boosts Photosynthetic Hydrogen Production in Chlamydomonas reinhardtii. FRONTIERS IN PLANT SCIENCE 2017; 8:1347. [PMID: 28824682 PMCID: PMC5540887 DOI: 10.3389/fpls.2017.01347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/19/2017] [Indexed: 05/26/2023]
Abstract
The protein superfamily of short-chain dehydrogenases/reductases (SDR), including members of the atypical type (aSDR), covers a huge range of catalyzed reactions and in vivo substrates. This superfamily also comprises isoflavone reductase-like (IRL) proteins, which are aSDRs highly homologous to isoflavone reductases from leguminous plants. The molecular function of IRLs in non-leguminous plants and green microalgae has not been identified as yet, but several lines of evidence point at their implication in reactive oxygen species homeostasis. The Chlamydomonas reinhardtii IRL protein IFR1 was identified in a previous study, analyzing the transcriptomic changes occurring during the acclimation to sulfur deprivation and anaerobiosis, a condition that triggers photobiological hydrogen production in this microalgae. Accumulation of the cytosolic IFR1 protein is induced by sulfur limitation as well as by the exposure of C. reinhardtii cells to reactive electrophile species (RES) such as reactive carbonyls. The latter has not been described for IRL proteins before. Over-accumulation of IFR1 in the singlet oxygen response 1 (sor1) mutant together with the presence of an electrophile response element, known to be required for SOR1-dependent gene activation as a response to RES, in the promoter of IFR1, indicate that IFR1 expression is controlled by the SOR1-dependent pathway. An implication of IFR1 into RES homeostasis, is further implied by a knock-down of IFR1, which results in a diminished tolerance toward RES. Intriguingly, IFR1 knock-down has a positive effect on photosystem II (PSII) stability under sulfur-deprived conditions used to trigger photobiological hydrogen production, by reducing PSII-dependent oxygen evolution, in C. reinhardtii. Reduced PSII photoinhibition in IFR1 knock-down strains prolongs the hydrogen production phase resulting in an almost doubled final hydrogen yield compared to the parental strain. Finally, IFR1 knock-down could be successfully used to further increase hydrogen yields of the high hydrogen-producing mutant stm6, demonstrating that IFR1 is a promising target for genetic engineering approaches aiming at an increased hydrogen production capacity of C. reinhardtii cells.
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Affiliation(s)
- Deepak Venkanna
- Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld UniversityBielefeld, Germany
| | - Christian Südfeld
- Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld UniversityBielefeld, Germany
| | - Thomas Baier
- Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld UniversityBielefeld, Germany
| | - Sarah V. Homburg
- Faculty of Engineering and Mathematics, Fermentation and Formulation of Biologicals and Chemicals, Bielefeld University of Applied SciencesBielefeld, Germany
| | - Anant V. Patel
- Faculty of Engineering and Mathematics, Fermentation and Formulation of Biologicals and Chemicals, Bielefeld University of Applied SciencesBielefeld, Germany
| | - Lutz Wobbe
- Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld UniversityBielefeld, Germany
| | - Olaf Kruse
- Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld UniversityBielefeld, Germany
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41
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Dall'Osto L, Cazzaniga S, Bressan M, Paleček D, Židek K, Niyogi KK, Fleming GR, Zigmantas D, Bassi R. Two mechanisms for dissipation of excess light in monomeric and trimeric light-harvesting complexes. NATURE PLANTS 2017; 3:17033. [PMID: 28394312 DOI: 10.1038/nplants.2017.33] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 02/14/2017] [Indexed: 05/19/2023]
Abstract
Oxygenic photoautotrophs require mechanisms for rapidly matching the level of chlorophyll excited states from light harvesting with the rate of electron transport from water to carbon dioxide. These photoprotective reactions prevent formation of reactive excited states and photoinhibition. The fastest response to excess illumination is the so-called non-photochemical quenching which, in higher plants, requires the luminal pH sensor PsbS and other yet unidentified components of the photosystem II antenna. Both trimeric light-harvesting complex II (LHCII) and monomeric LHC proteins have been indicated as site(s) of the heat-dissipative reactions. Different mechanisms have been proposed: energy transfer to a lutein quencher in trimers, formation of a zeaxanthin radical cation in monomers. Here, we report on the construction of a mutant lacking all monomeric LHC proteins but retaining LHCII trimers. Its non-photochemical quenching induction rate was substantially slower with respect to the wild type. A carotenoid radical cation signal was detected in the wild type, although it was lost in the mutant. We conclude that non-photochemical quenching is catalysed by two independent mechanisms, with the fastest activated response catalysed within monomeric LHC proteins depending on both zeaxanthin and lutein and on the formation of a radical cation. Trimeric LHCII was responsible for the slowly activated quenching component whereas inclusion in supercomplexes was not required. This latter activity does not depend on lutein nor on charge transfer events, whereas zeaxanthin was essential.
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Affiliation(s)
- Luca Dall'Osto
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Stefano Cazzaniga
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Mauro Bressan
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - David Paleček
- Department of Chemical Physics, Lund University, Getingevägen 60, Lund S-22241, Sweden
| | - Karel Židek
- Department of Chemical Physics, Lund University, Getingevägen 60, Lund S-22241, Sweden
| | - Krishna K Niyogi
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley 94720-3102, California, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley 94720, California, USA
| | - Graham R Fleming
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley 94720, California, USA
- Graduate Group in Applied Science and Technology, University of California, Berkeley 94720, California, USA
- Department of Chemistry, Hildebrand B77, University of California, Berkeley 94720-1460, California, USA
| | - Donatas Zigmantas
- Department of Chemical Physics, Lund University, Getingevägen 60, Lund S-22241, Sweden
| | - Roberto Bassi
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
- Consiglio Nazionale delle Ricerche (CNR), Istituto per la Protezione delle Piante (IPP), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy
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42
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Essemine J, Xiao Y, Qu M, Mi H, Zhu XG. Cyclic electron flow may provide some protection against PSII photoinhibition in rice (Oryza sativa L.) leaves under heat stress. JOURNAL OF PLANT PHYSIOLOGY 2017; 211:138-146. [PMID: 28199904 DOI: 10.1016/j.jplph.2017.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/24/2016] [Accepted: 01/20/2017] [Indexed: 05/08/2023]
Abstract
Previously we have shown that a quick down-regulation in PSI activity compares to that of PSII following short-term heat stress for two rice groups including C4023 and Q4149, studied herein. These accessions were identified to have different natural capacities in driving cyclic electron flow (CEF) around PSI; i.e., low CEF (lcef) and high CEF (hcef) for C4023 and Q4149, respectively. The aim of this study was to investigate whether these two lines have different mechanisms of protecting photosystem II from photodamage under heat stress. We observed a stepwise alteration in the shape of Chl a fluorescence induction (OJIP) with increasing temperature treatment. The effect of 44°C treatment on the damping in Chl a fluorescence was more pronounced in C4023 than in Q4149. Likewise, we noted a disruption in the I-step, a decline in the Fv due to a strong damping in the Fm, and a slight increase in the F0. Normalized data demonstrated that the I-step seems more susceptible to 44°C in C4023 than in Q4149. We also measured the redox states of plastocyanin (PC) and P700 by monitoring the transmission changes at 820nm (I820), and observed a disturbance in the oxidation/reduction kinetics of PC and P700. The decline in the amplitude of their oxidation was shown to be about 29% and 13% for C4023 and Q4149, respectively. The electropotential component (Δφ) of ms-DLE appeared more sensitive to temperature stress than the chemical component (ΔpH), and the impact of heat was more evident and drastic in C4023 than in Q4149. Under heat stress, we noticed a concomitant decline in the primary photochemistry of PSII as well as in both the membrane energization process and the lumen protonation for both accessions, and it is evident that heat affects these parameters more in C4023 than in Q4149. All these data suggest that higher CET can confer higher photoprotection to PSII in rice lines, which can be a desirable trait during rice breeding, especially in the context of a "warming" world.
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Affiliation(s)
- Jemaa Essemine
- CAS-Key Laboratory for Computational Biology and State Key Laboratory for Hybrid Rice, Partner Institute for Computational Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yi Xiao
- CAS-Key Laboratory for Computational Biology and State Key Laboratory for Hybrid Rice, Partner Institute for Computational Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Mingnan Qu
- CAS-Key Laboratory for Computational Biology and State Key Laboratory for Hybrid Rice, Partner Institute for Computational Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Hualing Mi
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xin-Guang Zhu
- CAS-Key Laboratory for Computational Biology and State Key Laboratory for Hybrid Rice, Partner Institute for Computational Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
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43
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Murphy CD, Roodvoets MS, Austen EJ, Dolan A, Barnett A, Campbell DA. Photoinactivation of Photosystem II in Prochlorococcus and Synechococcus. PLoS One 2017; 12:e0168991. [PMID: 28129341 PMCID: PMC5271679 DOI: 10.1371/journal.pone.0168991] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 12/10/2016] [Indexed: 01/15/2023] Open
Abstract
The marine picocyanobacteria Synechococcus and Prochlorococcus numerically dominate open ocean phytoplankton. Although evolutionarily related they are ecologically distinct, with different strategies to harvest, manage and exploit light. We grew representative strains of Synechococcus and Prochlorococcus and tracked their susceptibility to photoinactivation of Photosystem II under a range of light levels. As expected blue light provoked more rapid photoinactivation than did an equivalent level of red light. The previous growth light level altered the susceptibility of Synechococcus, but not Prochlorococcus, to this photoinactivation. We resolved a simple linear pattern when we expressed the yield of photoinactivation on the basis of photons delivered to Photosystem II photochemistry, plotted versus excitation pressure upon Photosystem II, the balance between excitation and downstream metabolism. A high excitation pressure increases the generation of reactive oxygen species, and thus increases the yield of photoinactivation of Photosystem II. Blue photons, however, retained a higher baseline photoinactivation across a wide range of excitation pressures. Our experiments thus uncovered the relative influences of the direct photoinactivation of Photosystem II by blue photons which dominates under low to moderate blue light, and photoinactivation as a side effect of reactive oxygen species which dominates under higher excitation pressure. Synechococcus enjoyed a positive metabolic return upon the repair or the synthesis of a Photosystem II, across the range of light levels we tested. In contrast Prochlorococcus only enjoyed a positive return upon synthesis of a Photosystem II up to 400 μmol photons m-2 s-1. These differential cost-benefits probably underlie the distinct photoacclimation strategies of the species.
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Affiliation(s)
- Cole D. Murphy
- Biochemistry and Chemistry, Mount Allison University, Sackville, New Brunswick, Canada
| | - Mitchell S. Roodvoets
- Biochemistry and Chemistry, Mount Allison University, Sackville, New Brunswick, Canada
| | - Emily J. Austen
- Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Allison Dolan
- Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Audrey Barnett
- Michigan Technological University, Houghton, Michigan, United States of America
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44
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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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45
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Sae-Tang P, Hihara Y, Yumoto I, Orikasa Y, Okuyama H, Nishiyama Y. Overexpressed Superoxide Dismutase and Catalase Act Synergistically to Protect the Repair of PSII during Photoinhibition in Synechococcus elongatus PCC 7942. PLANT & CELL PHYSIOLOGY 2016; 57:1899-1907. [PMID: 27328698 DOI: 10.1093/pcp/pcw110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/03/2016] [Indexed: 06/06/2023]
Abstract
The repair of PSII under strong light is particularly sensitive to reactive oxygen species (ROS), such as the superoxide radical and hydrogen peroxide, and these ROS are efficiently scavenged by superoxide dismutase (SOD) and catalase. In the present study, we generated transformants of the cyanobacterium Synechococcus elongatus PCC 7942 that overexpressed an iron superoxide dismutase (Fe-SOD) from Synechocystis sp. PCC 6803; a highly active catalase (VktA) from Vibrio rumoiensis; and both enzymes together. Then we examined the sensitivity of PSII to photoinhibition in the three strains. In cells that overexpressed either Fe-SOD or VktA, PSII was more tolerant to strong light than it was in wild-type cells. Moreover, in cells that overexpressed both Fe-SOD and VktA, PSII was even more tolerant to strong light. However, the rate of photodamage to PSII, as monitored in the presence of chloramphenicol, was similar in all three transformant strains and in wild-type cells, suggesting that the overexpression of these ROS-scavenging enzymes might not protect PSII from photodamage but might protect the repair of PSII. Under strong light, intracellular levels of ROS fell significantly, and the synthesis de novo of proteins that are required for the repair of PSII, such as the D1 protein, was enhanced. Our observations suggest that overexpressed Fe-SOD and VktA might act synergistically to alleviate the photoinhibition of PSII by reducing intracellular levels of ROS, with resultant protection of the repair of PSII from oxidative inhibition.
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Affiliation(s)
- Penporn Sae-Tang
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570 Japan
| | - Yukako Hihara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570 Japan Institute for Environmental Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570 Japan
| | - Isao Yumoto
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, 062-8517 Japan
| | - Yoshitake Orikasa
- Department of Food Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, 080-8555 Japan
| | - Hidetoshi Okuyama
- Laboratory of Environmental Molecular Biology, Faculty of Environmental Earth Science, Hokkaido University, Kita-ku, Sapporo, 060-0810 Japan
| | - Yoshitaka Nishiyama
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570 Japan Institute for Environmental Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570 Japan
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46
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Zabelin AA, Neverov KV, Krasnovsky AA, Shkuropatova VA, Shuvalov VA, Shkuropatov AY. Characterization of the low-temperature triplet state of chlorophyll in photosystem II core complexes: Application of phosphorescence measurements and Fourier transform infrared spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:782-8. [PMID: 27040752 DOI: 10.1016/j.bbabio.2016.03.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/23/2016] [Accepted: 03/28/2016] [Indexed: 10/21/2022]
Abstract
Phosphorescence measurements at 77 K and light-induced FTIR difference spectroscopy at 95 K were applied to study of the triplet state of chlorophyll a ((3)Chl) in photosystem II (PSII) core complexes isolated from spinach. Using both methods, (3)Chl was observed in the core preparations with doubly reduced primary quinone acceptor QA. The spectral parameters of Chl phosphorescence resemble those in the isolated PSII reaction centers (RCs). The main spectral maximum and the lifetime of the phosphorescence corresponded to 955±1 nm and of 1.65±0.05 ms respectively; in the excitation spectrum, the absorption maxima of all core complex pigments (Chl, pheophytin a (Pheo), and β-carotene) were observed. The differential signal at 1667(-)/1628(+)cm(-1) reflecting a downshift of the stretching frequency of the 13(1)-keto C=O group of Chl was found to dominate in the triplet-minus-singlet FTIR difference spectrum of core complexes. Based on FTIR results and literature data, it is proposed that (3)Chl is mostly localized on the accessory chlorophyll that is in triplet equilibrium with P680. Analysis of the data suggests that the Chl triplet state responsible for the phosphorescence and the FTIR difference spectrum is mainly generated due to charge recombination in the reaction center radical pair P680(+)PheoD1(-), and the energy and temporal parameters of this triplet state as well as the molecular environment and interactions of the triplet-bearing Chl molecule are similar in the PSII core complexes and isolated PSII RCs.
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Affiliation(s)
- Alexey A Zabelin
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| | - Konstantin V Neverov
- A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr., 33, Moscow 119071, Russian Federation; Biology Department, M.V. Lomonosov Moscow State University, Vorobyovy Gory, Moscow 119992, Russian Federation
| | - Alexander A Krasnovsky
- A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr., 33, Moscow 119071, Russian Federation; Biology Department, M.V. Lomonosov Moscow State University, Vorobyovy Gory, Moscow 119992, Russian Federation
| | - Valentina A Shkuropatova
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| | - Vladimir A Shuvalov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| | - Anatoly Ya Shkuropatov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation.
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47
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Huang JY, Chiu YF, Ortega JM, Wang HT, Tseng TS, Ke SC, Roncel M, Chu HA. Mutations of Cytochrome b559 and PsbJ on and near the QC Site in Photosystem II Influence the Regulation of Short-Term Light Response and Photosynthetic Growth of the Cyanobacterium Synechocystis sp. PCC 6803. Biochemistry 2016; 55:2214-26. [DOI: 10.1021/acs.biochem.6b00133] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Jine-Yung Huang
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Fang Chiu
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - José M. Ortega
- Instituto
de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Avda. Américo Vespucio 49, 41092 Seville, Spain
| | - Hsing-Ting Wang
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Tien-Sheng Tseng
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Shyue-Chu Ke
- Department
of Physics, National Dong Hwa University, Hualien 97401, Taiwan
| | - Mercedes Roncel
- Instituto
de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Avda. Américo Vespucio 49, 41092 Seville, Spain
| | - Hsiu-An Chu
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
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48
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Fischer WW, Hemp J, Valentine JS. How did life survive Earth's great oxygenation? Curr Opin Chem Biol 2016; 31:166-78. [PMID: 27043270 DOI: 10.1016/j.cbpa.2016.03.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 03/11/2016] [Accepted: 03/15/2016] [Indexed: 12/26/2022]
Abstract
Life on Earth originated and evolved in anoxic environments. Around 2.4 billion-years-ago, ancestors of Cyanobacteria invented oxygenic photosynthesis, producing substantial amounts of O2 as a byproduct of phototrophic water oxidation. The sudden appearance of O2 would have led to significant oxidative stress due to incompatibilities with core cellular biochemical processes. Here we examine this problem through the lens of Cyanobacteria-the first taxa to observe significant fluxes of intracellular dioxygen. These early oxygenic organisms likely adapted to the oxidative stress by co-opting preexisting systems (exaptation) with fortuitous antioxidant properties. Over time more advanced antioxidant systems evolved, allowing Cyanobacteria to adapt to an aerobic lifestyle and become the most important environmental engineers in Earth history.
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Affiliation(s)
- Woodward W Fischer
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States.
| | - James Hemp
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States
| | - Joan Selverstone Valentine
- Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095, United States.
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49
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Fan DY, Ye ZP, Wang SC, Chow WS. Multiple roles of oxygen in the photoinactivation and dynamic repair of Photosystem II in spinach leaves. PHOTOSYNTHESIS RESEARCH 2016; 127:307-319. [PMID: 26297354 DOI: 10.1007/s11120-015-0185-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 08/13/2015] [Indexed: 06/04/2023]
Abstract
Oxygen effects have long been ambiguous: exacerbating, being indifferent to, or ameliorating the net photoinactivation of Photosystem II (PS II). We scrutinized the time course of PS II photoinactivation (characterized by rate coefficient k i) in the absence of repair, or when recovery (characterized by k r) occurred simultaneously in CO2 ± O2. Oxygen exacerbated photoinactivation per se, but alleviated it by mediating the utilization of electrons. With repair permitted, the gradual net loss of functional PS II during illumination of leaves was better described phenomenologically by introducing τ, the time for an initial k r to decrease by half. At 1500 μmol photons m(-2) s(-1), oxygen decreased the initial k r but increased τ. Similarly, at even higher irradiance in air, there was a further decrease in the initial k r and increase in τ. These observations are consistent with an empirical model that (1) oxygen increased k i via oxidative stress but decreased it by mediating the utilization of electrons; and (2) reactive oxygen species stimulated the degradation of photodamaged D1 protein in PS II (characterized by k d), but inhibited the de novo synthesis of D1 (characterized by k s), and that the balance between these effects determines the net effect of O2 on PS II functionality.
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Affiliation(s)
- Da-Yong Fan
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
- Division of Plant Sciences, Research School of Biology, The Australian National University, 46 Sullivans Creek Road, Acton, ACT, 2601, Australia
| | - Zi-Piao Ye
- School of Life Sciences, Jinggangshan University, Ji'an, 343009, China
- College of Mathematics and Physics, Jinggangshan University, Ji'an, 343009, China
| | - Shi-Chang Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
| | - Wah Soon Chow
- Division of Plant Sciences, Research School of Biology, The Australian National University, 46 Sullivans Creek Road, Acton, ACT, 2601, Australia.
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50
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Ding S, Jiang R, Lu Q, Wen X, Lu C. Glutathione reductase 2 maintains the function of photosystem II in Arabidopsis under excess light. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:665-77. [PMID: 26906429 DOI: 10.1016/j.bbabio.2016.02.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/28/2016] [Accepted: 02/19/2016] [Indexed: 12/18/2022]
Abstract
Glutathione reductase plays a crucial role in the elimination of H(2)O(2) molecules via the ascorbate-glutathione cycle. In this study, we used transgenic Arabidopsis plants with decreased glutathione reductase 2 (GR2) levels to investigate whether this GR2 activity protects the photosynthetic machinery under excess light. The transgenic plants were highly sensitive to excess light and accumulated high levels of H(2)O(2). Photosystem II (PSII) activity was significantly decreased in transgenic plants. Flash-induced fluorescence relaxation and thermoluminescence measurements demonstrated inhibition of electron transfer between Q(A) and Q(B) and decreased redox potential of Q(B) in transgenic plants. Immunoblot and blue native gel analysis showed that the levels of PSII proteins and PSII complexes were decreased in transgenic plants. Analyses of the repair of photodamaged PSII and in vivo pulse labeling of thylakoid proteins showed that the repair of photodamaged PSII is inhibited due to the inhibition of the synthesis of the D1 protein de novo in transgenic plants. Taken together, our results suggest that under excess light conditions, GR2 plays an important role in maintaining both the function of the acceptor side of PSII and the repair of photodamaged PSII by preventing the accumulation of H(2)O(2). In addition, our results provide details of the role of H(2)O(2) in vivo accumulation in photoinhibition in plants.
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Affiliation(s)
- Shunhua Ding
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Rui Jiang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingtao Lu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xiaogang Wen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Congming Lu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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