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Begam K, Aksu H, Dunietz BD. Antioxidative Triplet Excitation Energy Transfer in Bacterial Reaction Center Using a Screened Range Separated Hybrid Functional. J Phys Chem B 2024. [PMID: 38687467 DOI: 10.1021/acs.jpcb.3c08501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Excess energy absorbed by photosystems (PSs) can result in photoinduced oxidative damage. Transfer of such energy within the core pigments of the reaction center in the form of triplet excitation is important in regulating and preserving the functionality of PSs. In the bacterial reaction center (BRC), the special pair (P) is understood to act as the electron donor in a photoinduced charge transfer process, triggering the charge separation process through the photoactive branch A pigments that experience a higher polarizing environment. At this work, triplet excitation energy transfer (TEET) in BRC is studied using a computational perspective to gain insights into the roles of the dielectric environment and interpigment orientations. We find in agreement with experimental observations that TEET proceeds through branch B. The TEET process toward branch B pigment is found to be significantly faster than the hypothetical process proceeding through branch A pigments with ps and ms time scales, respectively. Our calculations find that conformational differences play a major role in this branch asymmetry in TEET, where the dielectric environment asymmetry plays only a secondary role in directing the TEET to proceed through branch B. We also address TEET processes asserting the role of carotenoid as the final triplet energy acceptor and in a mutant form, where the branch pigments adjacent to P are replaced by bacteriopheophytins. The necessary electronic excitation energies and electronic state couplings are calculated by the recently developed polarization-consistent framework combining a screened range-separated hybrid functional and a polarizable continuum mode. The polarization-consistent potential energy surfaces are used to parametrize the quantum mechanical approach, implementing Fermi's golden rule expression of the TEET rate calculations.
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Affiliation(s)
- Khadiza Begam
- Department of Physics, Kent State University, Kent, Ohio 44242, United States
| | - Huseyin Aksu
- Department of Physics, Faculty of Science at Canakkale Onsekiz Mart University, Canakkale 17100, Turkey
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, United States
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2
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Su F, Li Y. Exogenous 24-epibrassinolide (EBL) facilitates cell growth of Chlorella pyrenoidosa under high temperatures by enhancing the photosynthetic energy utilization and alleviating oxidative damage. JOURNAL OF PHYCOLOGY 2024; 60:517-527. [PMID: 38451781 DOI: 10.1111/jpy.13440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 01/30/2024] [Accepted: 02/05/2024] [Indexed: 03/09/2024]
Abstract
The microalga Chlorella pyrenoidosa is cultivated extensively for its constituents, which are of significant economic worth. Large-scale growth of C. pyrenoidosa in outdoor environments is subject to various stressors such as elevated temperature. The purpose of this study was to assess the protective effects of exogenous 24-epibrassinolide (EBL) on C. pyrenoidosa under high-temperature conditions. Compared to a temperature of 30°C, increasing the temperature to 43°C reduced the enzymatic capacity for carbon assimilation and resulted in the buildup of reactive oxygen species (ROS), thus reducing photosynthesis and proliferation. It was observed that exogenous EBL protected C. pyrenoidosa cells against high temperatures, with an optimal EBL concentration of 100 nM, resulting in enhanced capacity for photosynthetic carbon assimilation with a notable reduction in the imbalance between the absorption of light and energy used under high-temperature conditions. The addition of 100 nM EBL resulted in a 25.4% increase in cell density when exposed to elevated temperatures for 7 days. In addition, exogenous EBL reduced ROS production and increased the activities of critical antioxidant enzymes. This, in turn, mitigated heat-induced oxidative damage, resulting in advantageous outcomes in terms of cellular development and maintenance.
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Affiliation(s)
- Fang Su
- Fujian Provincial Key Lab of Coastal Basin Environment, Ocean College, Fujian Polytechnic Normal University, Fuqing, Fujian, China
| | - Yongfu Li
- Jiangsu Province Engineering Research Center for Marine Bioresources Sustainable Utilization, Key Laboratory of Marine Hazards Forecasting, Ministry of Natural Resources, College of Oceanography, Hohai University, Nanjing, China
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Morelli L, Havurinne V, Madeira D, Martins P, Cartaxana P, Cruz S. Photoprotective mechanisms in Elysia species hosting Acetabularia chloroplasts shed light on host-donor compatibility in photosynthetic sea slugs. PHYSIOLOGIA PLANTARUM 2024; 176:e14273. [PMID: 38566156 DOI: 10.1111/ppl.14273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/13/2024] [Accepted: 03/18/2024] [Indexed: 04/04/2024]
Abstract
Sacoglossa sea slugs have garnered attention due to their ability to retain intracellular functional chloroplasts from algae, while degrading other algal cell components. While protective mechanisms that limit oxidative damage under excessive light are well documented in plants and algae, the photoprotective strategies employed by these photosynthetic sea slugs remain unresolved. Species within the genus Elysia are known to retain chloroplasts from various algal sources, but the extent to which the metabolic processes from the donor algae can be sustained by the sea slugs is unclear. By comparing responses to high-light conditions through kinetic analyses, molecular techniques, and biochemical assays, this study shows significant differences between two photosynthetic Elysia species with chloroplasts derived from the green alga Acetabularia acetabulum. Notably, Elysia timida displayed remarkable tolerance to high-light stress and sophisticated photoprotective mechanisms such as an active xanthophyll cycle, efficient D1 protein recycling, accumulation of heat-shock proteins and α-tocopherol. In contrast, Elysia crispata exhibited absence or limitations in these photoprotective strategies. Our findings emphasize the intricate relationship between the host animal and the stolen chloroplasts, highlighting different capacities to protect the photosynthetic organelle from oxidative damage.
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Affiliation(s)
- Luca Morelli
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Portugal
| | - Vesa Havurinne
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Portugal
| | - Diana Madeira
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Portugal
| | - Patrícia Martins
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Portugal
| | - Paulo Cartaxana
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Portugal
| | - Sónia Cruz
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Portugal
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4
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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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5
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Zavafer A, Bates H, Mancilla C, Ralph PJ. Phenomics: conceptualization and importance for plant physiology. TRENDS IN PLANT SCIENCE 2023; 28:1004-1013. [PMID: 37137749 DOI: 10.1016/j.tplants.2023.03.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 03/21/2023] [Accepted: 03/30/2023] [Indexed: 05/05/2023]
Abstract
Phenomics is a relatively new discipline of biology that has been widely applied in several fields, mainly in crop sciences. We reviewed the concepts used in this discipline (particularly for plants) and found a lack of consensus on what defines a phenomic study. Furthermore, phenomics has been primarily developed around its technical aspects (operationalization), while the conceptual framework of the actual research lags behind. Each research group has given its own interpretation of this 'omic' and thus unwittingly created a 'conceptual controversy'. Addressing this issue is of particular importance, as the experimental designs and concepts of phenomics are so diverse that it is difficult to compare studies. In this opinion article, we evaluate the conceptual framework of phenomics.
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Affiliation(s)
- Alonso Zavafer
- Climate Change Cluster, University of Technology Sydney, Sydney, Australia; Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada; Department of Engineering, Brock University, St. Catharines, Ontario, Canada.
| | - Harvey Bates
- Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Cristian Mancilla
- Department of Engineering, Brock University, St. Catharines, Ontario, Canada
| | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, Sydney, Australia
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Moustakas M, Sperdouli I, Moustaka J, Şaş B, İşgören S, Morales F. Mechanistic Insights on Salicylic Acid Mediated Enhancement of Photosystem II Function in Oregano Seedlings Subjected to Moderate Drought Stress. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12030518. [PMID: 36771603 PMCID: PMC9919124 DOI: 10.3390/plants12030518] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/15/2023] [Accepted: 01/19/2023] [Indexed: 06/12/2023]
Abstract
Dramatic climate change has led to an increase in the intensity and frequency of drought episodes and, together with the high light conditions of the Mediterranean area, detrimentally influences crop production. Salicylic acid (SA) has been shown to supress phototoxicity, offering photosystem II (PSII) photoprotection. In the current study, we attempted to reveal the mechanism by which SA is improving PSII efficiency in oregano seedlings under moderate drought stress (MoDS). Foliar application of SA decreased chlorophyll content under normal growth conditions, but under MoDS increased chlorophyll content, compared to H2O-sprayed oregano seedlings. SA improved the PSII efficiency of oregano seedlings under normal growth conditions at high light (HL), and under MoDS, at both low light (LL) and HL. The mechanism by which, under normal growth conditions and HL, SA sprayed oregano seedlings compared to H2O-sprayed exhibited a more efficient PSII photochemistry, was the increased (17%) fraction of open PSII reaction centers (qp), and the increased (7%) efficiency of these open reaction centers (Fv'/Fm'), which resulted in an enhanced (24%) electron transport rate (ETR). SA application under MoDS, by modulating chlorophyll content, resulted in optimized antenna size and enhanced effective quantum yield of PSII photochemistry (ΦPSII) under both LL (7%) and HL (25%), compared to non-SA-sprayed oregano seedlings. This increased effective quantum yield of PSII photochemistry (ΦPSII) was due to the enhanced efficiency of the oxygen evolving complex (OEC), and the increased fraction of open PSII reaction centers (qp), which resulted in an increased electron transport rate (ETR) and a lower amount of singlet oxygen (1O2) production with less excess excitation energy (EXC).
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Affiliation(s)
- Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Ilektra Sperdouli
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organisation–Demeter (ELGO-Demeter), 57001 Thessaloniki, Greece
| | - Julietta Moustaka
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Begüm Şaş
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Sumrunaz İşgören
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Fermín Morales
- Instituto de Agrobiotecnología (IdAB), CSIC-Gobierno de Navarra, Avda. de Pamplona 123, 31192 Navarra, Spain
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7
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Mattila H, Mishra S, Tyystjärvi T, Tyystjärvi E. Singlet oxygen production by photosystem II is caused by misses of the oxygen evolving complex. THE NEW PHYTOLOGIST 2023; 237:113-125. [PMID: 36161283 PMCID: PMC10092662 DOI: 10.1111/nph.18514] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 09/10/2022] [Indexed: 06/12/2023]
Abstract
Singlet oxygen (1 O2 ) is a harmful species that functions also as a signaling molecule. In chloroplasts, 1 O2 is produced via charge recombination reactions in photosystem II, but which recombination pathway(s) produce triplet Chl and 1 O2 remains open. Furthermore, the role of 1 O2 in photoinhibition is not clear. We compared temperature dependences of 1 O2 production, photoinhibition, and recombination pathways. 1 O2 production by pumpkin thylakoids increased from -2 to +35°C, ruling out recombination of the primary charge pair as a main contributor. S2 QA - or S2 QB - recombination pathways, in turn, had too steep temperature dependences. Instead, the temperature dependence of 1 O2 production matched that of misses (failures of the oxygen (O2 ) evolving complex to advance an S-state). Photoinhibition in vitro and in vivo (also in Synechocystis), and in the presence or absence of O2 , had the same temperature dependence, but ultraviolet (UV)-radiation-caused photoinhibition showed a weaker temperature response. We suggest that the miss-associated recombination of P680 + QA - is the main producer of 1 O2 . Our results indicate three parallel photoinhibition mechanisms. The manganese mechanism dominates in UV radiation but also functions in white light. Mechanisms that depend on light absorption by Chls, having 1 O2 or long-lived P680 + as damaging agents, dominate in red light.
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Affiliation(s)
- Heta Mattila
- Department of Life Technologies/Molecular Plant BiologyUniversity of TurkuFI‐20014TurkuFinland
| | - Sujata Mishra
- Department of Life Technologies/Molecular Plant BiologyUniversity of TurkuFI‐20014TurkuFinland
| | - Taina Tyystjärvi
- Department of Life Technologies/Molecular Plant BiologyUniversity of TurkuFI‐20014TurkuFinland
| | - Esa Tyystjärvi
- Department of Life Technologies/Molecular Plant BiologyUniversity of TurkuFI‐20014TurkuFinland
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8
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Kono M, Miyata K, Matsuzawa S, Noguchi T, Oguchi R, Suzuki Y, Terashima I. Mixed population hypothesis of the active and inactive PSII complexes opens a new door for photoinhibition and fluorescence studies: an ecophysiological perspective. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:917-925. [PMID: 35821662 DOI: 10.1071/fp21355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
The current hypotheses for the mechanisms of photosystem II (PSII) photodamage in vivo remain split on the primary damage site. However, most researchers have considered that PSII is inhibited by a sole mechanism and that the photoinhibited PSII consists of one population. In this perspective, we propose 'the mixed population hypothesis', in which there are four PSII populations: PSII with active/inactive Mn4 CaO5 oxygen-evolving complex respectively with functional/damaged primary quinone (QA ) reduction activity. This hypothesis provides a new insight into not only the PSII photoinhibition/photoprotection studies but also the repair process. We discuss our new data implying that the repair rate differs in the respective PSII populations.
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Affiliation(s)
- Masaru Kono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kazunori Miyata
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Sae Matsuzawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takaya Noguchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Riichi Oguchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yoshihiro Suzuki
- Department of Biological Sciences, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka-City, Kanagawa 259-1293, Japan
| | - Ichiro Terashima
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Yi X, Yao H, Fan D, Zhu X, Losciale P, Zhang Y, Zhang W, Chow WS. The energy cost of repairing photoinactivated photosystem II: an experimental determination in cotton leaf discs. THE NEW PHYTOLOGIST 2022; 235:446-456. [PMID: 35451127 PMCID: PMC9320836 DOI: 10.1111/nph.18165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 03/31/2022] [Indexed: 05/12/2023]
Abstract
Photosystem II (PSII), which splits water molecules at minimal excess photochemical potential, is inevitably photoinactivated during photosynthesis, resulting in compromised photosynthetic efficiency unless it is repaired. The energy cost of PSII repair is currently uncertain, despite attempts to calculate it. We experimentally determined the energy cost of repairing each photoinactivated PSII in cotton (Gossypium hirsutum) leaves, which are capable of repairing PSII in darkness. As an upper limit, 24 000 adenosine triphosphate (ATP) molecules (including any guanosine triphosphate synthesized at the expense of ATP) were required to repair one entire PSII complex. Further, over a 7-h illumination period at 526-1953 μmol photons m-2 s-1 , the ATP requirement for PSII repair was on average up to 4.6% of the ATP required for the gross carbon assimilation. Each of these two measures of ATP requirement for PSII repair is two- to three-fold greater than the respective reported calculated value. Possible additional energy sinks in the PSII repair cycle are discussed.
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Affiliation(s)
- Xiao‐Ping Yi
- Key Laboratory of Oasis Eco‐agricultureXinjiang Production and Construction CorpsShihezi UniversityShihezi832003China
- College of Agronomy and BiotechnologySouthwest UniversityChongqing400715China
| | - He‐Sheng Yao
- Key Laboratory of Oasis Eco‐agricultureXinjiang Production and Construction CorpsShihezi UniversityShihezi832003China
- College of Agronomy and BiotechnologySouthwest UniversityChongqing400715China
| | - Da‐Yong Fan
- College of ForestryBeijing Forestry UniversityBeijing100083China
- Division of Plant Sciences, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
| | - Xin‐Guang Zhu
- State Key Laboratory of Plant Molecular GeneticsCentre of Excellence for Molecular Plant and Shanghai Institute of Plant Physiology and EcologyChinese Academy of Sciences300 Fenglin RoadShanghai200032China
| | - Pasquale Losciale
- Dipartimento di Scienze del Suolo della Pianta e degli AlimentiUnivarsità degli Studi di BariVia Amendola 165/A70126BariItaly
| | - Ya‐Li Zhang
- Key Laboratory of Oasis Eco‐agricultureXinjiang Production and Construction CorpsShihezi UniversityShihezi832003China
| | - Wang‐Feng Zhang
- Key Laboratory of Oasis Eco‐agricultureXinjiang Production and Construction CorpsShihezi UniversityShihezi832003China
| | - Wah Soon Chow
- Division of Plant Sciences, Research School of BiologyThe Australian National UniversityCanberraACT2601Australia
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Moustakas M, Sperdouli I, Adamakis IDS, Moustaka J, İşgören S, Şaş B. Harnessing the Role of Foliar Applied Salicylic Acid in Decreasing Chlorophyll Content to Reassess Photosystem II Photoprotection in Crop Plants. Int J Mol Sci 2022; 23:ijms23137038. [PMID: 35806045 PMCID: PMC9266436 DOI: 10.3390/ijms23137038] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 02/06/2023] Open
Abstract
Salicylic acid (SA), an essential plant hormone, has received much attention due to its role in modulating the adverse effects of biotic and abiotic stresses, acting as an antioxidant and plant growth regulator. However, its role in photosynthesis under non stress conditions is controversial. By chlorophyll fluorescence imaging analysis, we evaluated the consequences of foliar applied 1 mM SA on photosystem II (PSII) efficiency of tomato (Solanum lycopersicum L.) plants and estimated the reactive oxygen species (ROS) generation. Tomato leaves sprayed with 1 mM SA displayed lower chlorophyll content, but the absorbed light energy was preferentially converted into photochemical energy rather than dissipated as thermal energy by non-photochemical quenching (NPQ), indicating photoprotective effects provided by the foliar applied SA. This decreased NPQ, after 72 h treatment by 1 mM SA, resulted in an increased electron transport rate (ETR). The molecular mechanism by which the absorbed light energy was more efficiently directed to photochemistry in the SA treated leaves was the increased fraction of the open PSII reaction centers (qp), and the increased efficiency of open reaction centers (Fv’/Fm’). SA induced a decrease in chlorophyll content, resulting in a decrease in non-regulated energy dissipated in PSII (ΦNO) under high light (HL) treatment, suggesting a lower amount of triplet excited state chlorophyll (3Chl*) molecules available to produce singlet oxygen (1O2). Yet, the increased efficiency, compared to the control, of the oxygen evolving complex (OEC) on the donor side of PSII, associated with lower formation of hydrogen peroxide (H2O2), also contributed to less creation of ROS. We conclude that under non stress conditions, foliar applied SA decreased chlorophyll content and suppressed phototoxicity, offering PSII photoprotection; thus, it can be regarded as a mechanism that reduces photoinhibition and photodamage, improving PSII efficiency in crop plants.
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Affiliation(s)
- Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (J.M.); (S.İ.); (B.Ş.)
- Correspondence:
| | - Ilektra Sperdouli
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organisation-Demeter (ELGO-Demeter), 57001 Thessaloniki, Greece;
| | | | - Julietta Moustaka
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (J.M.); (S.İ.); (B.Ş.)
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Sumrunaz İşgören
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (J.M.); (S.İ.); (B.Ş.)
| | - Begüm Şaş
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (J.M.); (S.İ.); (B.Ş.)
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11
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Kato Y, Noguchi T. Redox properties and regulatory mechanism of the iron-quinone electron acceptor in photosystem II as revealed by FTIR spectroelectrochemistry. PHOTOSYNTHESIS RESEARCH 2022; 152:135-151. [PMID: 34985636 DOI: 10.1007/s11120-021-00894-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 12/24/2021] [Indexed: 05/09/2023]
Abstract
Photosystem II (PSII) performs oxidation of water and reduction of plastoquinone through light-induced electron transfer. Electron transfer reactions at individual redox cofactors are controlled by their redox potentials, and the forward and backward electron flows in PSII are regulated by tuning them. It is, thus, crucial to accurately estimate the redox potentials of the cofactors and their shifts by environmental changes to understand the regulatory mechanisms in PSII. Fourier-transform infrared (FTIR) spectroelectrochemistry combined with a light-induced difference technique is a powerful method to investigate the mechanisms of the redox reactions in PSII. In this review, we introduce the methodology and the application of this method in the studies of the iron-quinone complex, which consists of two plastoquinone molecules, QA and QB, and the non-heme iron, on the electron-acceptor side of PSII. It is shown that FTIR spectroelectrochemistry is a useful method not only for estimating the redox potentials but also for detecting the reactions of nearby amino-acid residues coupled with the redox reactions.
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Affiliation(s)
- Yuki Kato
- 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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12
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Regulation of the generation of reactive oxygen species during photosynthetic electron transport. Biochem Soc Trans 2022; 50:1025-1034. [PMID: 35437580 DOI: 10.1042/bst20211246] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 11/17/2022]
Abstract
Light capture by chlorophylls and photosynthetic electron transport bury the risk of the generation of reactive oxygen species (ROS) including singlet oxygen, superoxide anion radicals and hydrogen peroxide. Rapid changes in light intensity, electron fluxes and accumulation of strong oxidants and reductants increase ROS production. Superoxide is mainly generated at the level of photosystem I while photosystem II is the main source of singlet oxygen. ROS can induce oxidative damage of the photosynthetic apparatus, however, ROS are also important to tune processes inside the chloroplast and participate in retrograde signalling regulating the expression of genes involved in acclimation responses. Under most physiological conditions light harvesting and photosynthetic electron transport are regulated to keep the level of ROS at a non-destructive level. Photosystem II is most prone to photoinhibition but can be quickly repaired while photosystem I is protected in most cases. The size of the transmembrane proton gradient is central for the onset of mechanisms that protect against photoinhibition. The proton gradient allows dissipation of excess energy as heat in the antenna systems and it regulates electron transport. pH-dependent slowing down of electron donation to photosystem I protects it against ROS generation and damage. Cyclic electron transfer and photoreduction of oxygen contribute to the size of the proton gradient. The yield of singlet oxygen production in photosystem II is regulated by changes in the midpoint potential of its primary quinone acceptor. In addition, numerous antioxidants inside the photosystems, the antenna and the thylakoid membrane quench or scavenge ROS.
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Akhtar P, Sipka G, Han W, Li X, Han G, Shen JR, Garab G, Tan HS, Lambrev PH. Ultrafast excitation quenching by the oxidized photosystem II reaction center. J Chem Phys 2022; 156:145101. [DOI: 10.1063/5.0086046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Photosystem II (PSII) is the pigment–protein complex driving the photoinduced oxidation of water and reduction of plastoquinone in all oxygenic photosynthetic organisms. Excitations in the antenna chlorophylls are photochemically trapped in the reaction center (RC) producing the chlorophyll–pheophytin radical ion pair P+ Pheo−. When electron donation from water is inhibited, the oxidized RC chlorophyll P+ acts as an excitation quencher, but knowledge on the kinetics of quenching is limited. Here, we used femtosecond transient absorption spectroscopy to compare the excitation dynamics of PSII with neutral and oxidized RC (P+). We find that equilibration in the core antenna has a major lifetime of about 300 fs, irrespective of the RC redox state. Two-dimensional electronic spectroscopy revealed additional slower energy equilibration occurring on timescales of 3–5 ps, concurrent with excitation trapping. The kinetics of PSII with open RC can be described well with previously proposed models according to which the radical pair P+ Pheo− is populated with a main lifetime of about 40 ps, which is primarily determined by energy transfer between the core antenna and the RC chlorophylls. Yet, in PSII with oxidized RC (P+), fast excitation quenching was observed with decay lifetimes as short as 3 ps and an average decay lifetime of about 90 ps, which is shorter than the excited-state lifetime of PSII with open RC. The underlying mechanism of this extremely fast quenching prompts further investigation.
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Affiliation(s)
- Parveen Akhtar
- School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, 637371, Singapore
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
- ELI-ALPS, ELI-HU Non-profit Ltd., Wolfgang Sandner u. 3, Szeged 6728, Hungary
| | - Gábor Sipka
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
| | - Wenhui Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xingyue Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Győző Garab
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
| | - Howe-Siang Tan
- School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, 637371, Singapore
| | - Petar H. Lambrev
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged 6726, Hungary
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Solymosi D, Shevela D, Allahverdiyeva Y. Nitric oxide represses photosystem II and NDH-1 in the cyanobacterium Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2022; 1863:148507. [PMID: 34728155 DOI: 10.1016/j.bbabio.2021.148507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 10/20/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022]
Abstract
Photosynthetic electron transfer comprises a series of light-induced redox reactions catalysed by multiprotein machinery in the thylakoid. These protein complexes possess cofactors susceptible to redox modifications by reactive small molecules. The gaseous radical nitric oxide (NO), a key signalling molecule in green algae and plants, has earlier been shown to bind to Photosystem (PS) II and obstruct electron transfer in plants. The effects of NO on cyanobacterial bioenergetics however, have long remained obscure. In this study, we exposed the model cyanobacterium Synechocystis sp. PCC 6803 to NO under anoxic conditions and followed changes in whole-cell fluorescence and oxidoreduction of P700 in vivo. Our results demonstrate that NO blocks photosynthetic electron transfer in cells by repressing PSII, PSI, and likely the NDH dehydrogenase-like complex 1 (NDH-1). We propose that iron‑sulfur clusters of NDH-1 complex may be affected by NO to such an extent that ferredoxin-derived electron injection to the plastoquinone pool, and thus cyclic electron transfer, may be inhibited. These findings reveal the profound effects of NO on Synechocystis cells and demonstrate the importance of controlled NO homeostasis in cyanobacteria.
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Affiliation(s)
- Daniel Solymosi
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, FI 20014, Finland
| | - Dmitry Shevela
- Chemical Biological Centre, Department of Chemistry, Umeå University, 90187 Umeå, Sweden
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, FI 20014, Finland.
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15
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Kato Y, Noguchi T. Effects of Stromal and Lumenal Side Perturbations on the Redox Potential of the Primary Quinone Electron Acceptor Q A in Photosystem II. Biochemistry 2021; 60:3697-3706. [PMID: 34784184 DOI: 10.1021/acs.biochem.1c00624] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The primary quinone electron acceptor QA is a key component in the electron transfer regulation in photosystem II (PSII), and hence accurate estimation of its redox potential, Em(QA-/QA), is crucial in understanding the regulatory mechanism. Although fluorescence detection has been extensively used for monitoring the redox state of QA, it was recently suggested that this method tends to provide a higher Em(QA-/QA) estimate depending on the sample status due to the effect of measuring light [Kato et al. (2019) Biochim. Biophys. Acta 1860, 148082]. In this study, we applied the Fourier transform infrared (FTIR) spectroelectrochemistry, which uses non-reactive infrared light to monitor the redox state of QA, to investigate the effects of stromal- and lumenal-side perturbations on Em(QA-/QA) in PSII. It was shown that replacement of bicarbonate bound to the non-heme iron with formate upshifted Em(QA-/QA) by ∼55 mV, consistent with the previous fluorescence measurement. In contrast, an Em(QA-/QA) difference between binding of 3-(3,4-dichlorophenyl)-1,1-dimethylurea and bromoxynil was found to be ∼30 mV, which is much smaller than the previous estimate, ∼100 mV, by the fluorescence method. This ∼30 mV difference was verified by the decay kinetics of the S2QA- recombination. On the lumenal side, Mn depletion hardly affected the Em(QA-/QA), confirming the previous FTIR result. However, removal of the extrinsic proteins by NaCl or CaCl2 wash downshifted the Em(QA-/QA) by 14-20 mV. These results suggest that electron flow through QA is regulated by changes both on the stromal and lumenal sides of PSII.
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Affiliation(s)
- Yuki Kato
- 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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16
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Tian L, Huang L, Cui H, Yang F, Li Y. The toxicological impact of the sunscreen active ingredient octinoxate on the photosynthesis activity of Chlorella sp. MARINE ENVIRONMENTAL RESEARCH 2021; 171:105469. [PMID: 34500299 DOI: 10.1016/j.marenvres.2021.105469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/13/2021] [Accepted: 08/27/2021] [Indexed: 06/13/2023]
Abstract
Products designed to filter ultraviolet (UV) light are responsible for growing levels of anthropogenic environmental contamination. Octinoxate (ONT) is among the most common UV filtering active ingredients in cosmetics and sunscreens. The present study was designed to evaluate the toxicological effects of ONT on the photosynthetic activity of the Chlorella species of marine microalgae. These analyses identified ONT as a potent photo-toxicant, the effects of which were more pronounced upon light exposure relative to in the dark. Short-term ONT exposure had no effect on photosynthetic electron transport capacity in the dark but did significantly reduce the ribulose-1,5-bisphosphate carboxylase/oxygenase activity in Chlorella cells, suggesting that this compound can directly suppress the photosynthetic Calvin cycle. When cells were subsequently exposed to light, the disruption of this cycle resulted in an excess of excitation energy, in turn driving the excessive generation of reactive oxygen species (ROS). ROS-mediated disruption of cellular metabolism further aggravated this ONT-induced microalgal damage. As such, under natural light conditions, these microalgae cells are exposed to increased oxidative stress that impairs their growth and causes pigment bleaching. Restricting the utilization of ONT-containing sunscreens thus has the potential to better preserve the integrity of aquatic and terrestrial ecosystems.
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Affiliation(s)
- Lin Tian
- College of Environmental Science & Engineering, Ocean University of China, Qingdao, 266100, China
| | - Lei Huang
- College of Environmental Science & Engineering, Ocean University of China, Qingdao, 266100, China.
| | - Hongwu Cui
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | - Feifei Yang
- School of Ocean Engineering, Jiangsu Ocean University, Lianyungang, 222005, China
| | - Yongfu Li
- College of Environmental Science & Engineering, Ocean University of China, Qingdao, 266100, China; CAS Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Institute of Oceanology, Qingdao, 266071, China.
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17
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Bashir F, Rehman AU, Szabó M, Vass I. Singlet oxygen damages the function of Photosystem II in isolated thylakoids and in the green alga Chlorella sorokiniana. PHOTOSYNTHESIS RESEARCH 2021; 149:93-105. [PMID: 34009505 PMCID: PMC8382655 DOI: 10.1007/s11120-021-00841-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
Singlet oxygen (1O2) is an important damaging agent, which is produced during illumination by the interaction of the triplet excited state pigment molecules with molecular oxygen. In cells of photosynthetic organisms 1O2 is formed primarily in chlorophyll containing complexes, and damages pigments, lipids, proteins and other cellular constituents in their environment. A useful approach to study the physiological role of 1O2 is the utilization of external photosensitizers. In the present study, we employed a multiwell plate-based screening method in combination with chlorophyll fluorescence imaging to characterize the effect of externally produced 1O2 on the photosynthetic activity of isolated thylakoid membranes and intact Chlorella sorokiniana cells. The results show that the external 1O2 produced by the photosensitization reactions of Rose Bengal damages Photosystem II both in isolated thylakoid membranes and in intact cells in a concentration dependent manner indicating that 1O2 plays a significant role in photodamage of Photosystem II.
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Affiliation(s)
- Faiza Bashir
- Biological Research Centre, Institute of Plant Biology, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Ateeq Ur Rehman
- 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, Sydney, Australia
| | - Imre Vass
- Biological Research Centre, Institute of Plant Biology, Eötvös Loránd Research Network (ELKH), Szeged, Hungary.
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18
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Havurinne V, Handrich M, Antinluoma M, Khorobrykh S, Gould SB, Tyystjärvi E. Genetic autonomy and low singlet oxygen yield support kleptoplast functionality in photosynthetic sea slugs. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5553-5568. [PMID: 33989402 PMCID: PMC8318255 DOI: 10.1093/jxb/erab216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/12/2021] [Indexed: 05/04/2023]
Abstract
The kleptoplastic sea slug Elysia chlorotica consumes Vaucheria litorea, stealing its plastids, which then photosynthesize inside the animal cells for months. We investigated the properties of V. litorea plastids to understand how they withstand the rigors of photosynthesis in isolation. Transcription of specific genes in laboratory-isolated V. litorea plastids was monitored for 7 days. The involvement of plastid-encoded FtsH, a key plastid maintenance protease, in recovery from photoinhibition in V. litorea was estimated in cycloheximide-treated cells. In vitro comparison of V. litorea and spinach thylakoids was applied to investigate reactive oxygen species formation in V. litorea. In comparison to other tested genes, the transcripts of ftsH and translation elongation factor EF-Tu (tufA) decreased slowly in isolated V. litorea plastids. Higher levels of FtsH were also evident in cycloheximide-treated cells during recovery from photoinhibition. Charge recombination in PSII of V. litorea was found to be fine-tuned to produce only small quantities of singlet oxygen, and the plastids also contained reactive oxygen species-protective compounds. Our results support the view that the genetic characteristics of the plastids are crucial in creating a photosynthetic sea slug. The plastid's autonomous repair machinery is likely enhanced by low singlet oxygen production and elevated expression of FtsH.
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Affiliation(s)
- Vesa Havurinne
- Department of Biotechnology/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Maria Handrich
- Department of Biology, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Mikko Antinluoma
- Department of Biotechnology/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Sergey Khorobrykh
- Department of Biotechnology/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Sven B Gould
- Department of Biology, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Esa Tyystjärvi
- Department of Biotechnology/Molecular Plant Biology, University of Turku, Turku, Finland
- Correspondence:
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Bassi R, Dall'Osto L. Dissipation of Light Energy Absorbed in Excess: The Molecular Mechanisms. ANNUAL REVIEW OF PLANT BIOLOGY 2021; 72:47-76. [PMID: 34143647 DOI: 10.1146/annurev-arplant-071720-015522] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Light is essential for photosynthesis. Nevertheless, its intensity widely changes depending on time of day, weather, season, and localization of individual leaves within canopies. This variability means that light collected by the light-harvesting system is often in excess with respect to photon fluence or spectral quality in the context of the capacity of photosynthetic metabolism to use ATP and reductants produced from the light reactions. Absorption of excess light can lead to increased production of excited, highly reactive intermediates, which expose photosynthetic organisms to serious risks of oxidative damage. Prevention and management of such stress are performed by photoprotective mechanisms, which operate by cutting down light absorption, limiting the generation of redox-active molecules, or scavenging reactive oxygen species that are released despite the operation of preventive mechanisms. Here, we describe the major physiological and molecular mechanisms of photoprotection involved in the harmless removal of the excess light energy absorbed by green algae and land plants. In vivo analyses of mutants targeting photosynthetic components and the enhanced resolution of spectroscopic techniques have highlighted specific mechanisms protecting the photosynthetic apparatus from overexcitation. Recent findings unveil a network of multiple interacting elements, the reaction times of which vary from a millisecond to weeks, that continuously maintain photosynthetic organisms within the narrow safety range between efficient light harvesting and photoprotection.
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Affiliation(s)
- Roberto Bassi
- Department of Biotechnology, University of Verona, 37134 Verona, Italy;
| | - Luca Dall'Osto
- Department of Biotechnology, University of Verona, 37134 Verona, Italy;
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20
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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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21
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Zhao J, Yu W, Zhang L, Liu J. Chlororespiration protects the photosynthetic apparatus against photoinhibition by alleviating inhibition of photodamaged-PSII repair in Haematococcus pluvialis at the green motile stage. ALGAL RES 2021. [DOI: 10.1016/j.algal.2020.102140] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Virtanen O, Khorobrykh S, Tyystjärvi E. Acclimation of Chlamydomonas reinhardtii to extremely strong light. PHOTOSYNTHESIS RESEARCH 2021; 147:91-106. [PMID: 33280077 PMCID: PMC7728646 DOI: 10.1007/s11120-020-00802-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 11/17/2020] [Indexed: 05/27/2023]
Abstract
Most photosynthetic organisms are sensitive to very high light, although acclimation mechanisms enable them to deal with exposure to strong light up to a point. Here we show that cultures of wild-type Chlamydomonas reinhardtii strain cc124, when exposed to photosynthetic photon flux density 3000 μmol m-2 s-1 for a couple of days, are able to suddenly attain the ability to grow and thrive. We compared the phenotypes of control cells and cells acclimated to this extreme light (EL). The results suggest that genetic or epigenetic variation, developing during maintenance of the population in moderate light, contributes to the acclimation capability. EL acclimation was associated with a high carotenoid-to-chlorophyll ratio and slowed down PSII charge recombination reactions, probably by affecting the pre-exponential Arrhenius factor of the rate constant. In agreement with these findings, EL acclimated cells showed only one tenth of the 1O2 level of control cells. In spite of low 1O2 levels, the rate of the damaging reaction of PSII photoinhibition was similar in EL acclimated and control cells. Furthermore, EL acclimation was associated with slow PSII electron transfer to artificial quinone acceptors. The data show that ability to grow and thrive in extremely strong light is not restricted to photoinhibition-resistant organisms such as Chlorella ohadii or to high-light tolerant mutants, but a wild-type strain of a common model microalga has this ability as well.
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Affiliation(s)
- Olli Virtanen
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Sergey Khorobrykh
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland.
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23
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Ahmed H, Pathak J, Rajneesh, Sonkar PK, Ganesan V, Häder DP, Sinha RP. Responses of a hot spring cyanobacterium under ultraviolet and photosynthetically active radiation: photosynthetic performance, antioxidative enzymes, mycosporine-like amino acid profiling and its antioxidative potentials. 3 Biotech 2021; 11:10. [PMID: 33442509 PMCID: PMC7778668 DOI: 10.1007/s13205-020-02562-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 11/19/2020] [Indexed: 01/24/2023] Open
Abstract
This study summarizes the response of a hot spring cyanobacterium Fischerella sp. strain HKAR-14, under simulated light conditions of ultraviolet radiation (UVR), photosynthetically active radiation (PAR), PAR + UV-A (PA) and PAR + UV-A + UV-B (PAB). Exposure to UVR caused a decline in growth and Chl a while total carotene content increased under PA and PAB. Maximum photochemical efficiency of photosystem II (F v /F m) and relative electron transport rate decreased significantly in PA and PAB exposure. Higher non-photochemical quenching and lower photochemical quenching values were observed in UVR-exposed samples as compared to the control. Levels of intracellular reactive oxygen species (ROS) increased significantly in PAB and PA. Fluorescence microscopic images showed an increase in green fluorescence, indicating the generation of ROS in UVR. The antioxidant machinery including superoxide dismutase, catalase and peroxidase showed an increase of 1.76-fold and 2.5-fold superoxide dismutase, 2.4-fold and 3.7-fold catalase, 1.83-fold and 2.5-fold peroxidase activities under PA and PAB, respectively. High-performance liquid chromatography equipped with photodiode array detector, electrospray ionization mass spectrometry, Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy analyses reveal the occurrence of a single mycosporine-like amino acid, shinorine (λ max 332.3 ± 2 nm, m/z 333.1), with a retention time of 1.157 min. The electrochemical characterization of shinorine was determined by cyclic voltammetry. The shinorine molecule possesses electrochemical activity and represents diffusion-controlled process in 0.1 M (pH 7.0) phosphate buffer. An antioxidant assay of shinorine showed its efficient activity as antioxidant which increased in a dose-dependent manner.
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Affiliation(s)
- Haseen Ahmed
- Laboratory of Photobiology and Molecular Microbiology, Center of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005 India
- Department of Botany, Government Girls P.G. College, Satna, MP 485001 India
| | - Jainendra Pathak
- Department of Botany, Pt. Jawaharlal Nehru College, Banda, 210001 India
| | - Rajneesh
- Laboratory of Photobiology and Molecular Microbiology, Center of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005 India
| | - Piyush K. Sonkar
- Department of Chemistry, MMV, Banaras Hindu University, Varanasi, India
| | - Vellaichamy Ganesan
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Donat-P. Häder
- Department of Biology, Emeritus of Friedrich-Alexander University, Neue Str. 9, 91096 Möhrendorf, Germany
| | - Rajeshwar P. Sinha
- Laboratory of Photobiology and Molecular Microbiology, Center of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005 India
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Li Z, Juneau P, Lian Y, Zhang W, Wang S, Wang C, Shu L, Yan Q, He Z, Xu K. Effects of Titanium Dioxide Nanoparticles on Photosynthetic and Antioxidative Processes of Scenedesmus obliquus. PLANTS 2020; 9:plants9121748. [PMID: 33321890 PMCID: PMC7763043 DOI: 10.3390/plants9121748] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 02/05/2023]
Abstract
The effects of the photocatalytic toxicity of titanium dioxide nanoparticle (nano-TiO2) on phytoplankton are well understood. However, as UV light intensity decreases sharply with the depth of the water column, the effects of nano-TiO2 itself on deeper water phytoplankton, such as green algae, need further research. In this research, we investigated the effects of three sizes of TiO2 (10, 50 and 200 nm) on the photosynthetic and antioxidative processes of Scenedesmus obliquus in the absence of UV light. We found that 50 nm and 10 nm TiO2 (10 mg/L) inhibited growth rates and the maximal photosystem II quantum yield compared to the control in Scenedesmus obliquus. The minimal and maximal fluorescence yields, and the contents of reactive oxygen species and lipid peroxidation, increased, indicating that photosynthetic energy/electrons transferred to oxygen and induced oxidative stress in nano-TiO2-treated samples. In addition, we found that aggregations of algae and 10 nm TiO2 were present, which could induce cell membrane disruption, and vacuoles were induced to cope with nano-TiO2 stress in Scenedesmus obliquus. These results enhance our understanding of the effects of nano-TiO2 on the photosynthetic and antioxidative processes of green algae, and provide basic information for evaluating the ecotoxicity of nano-TiO2 in freshwater ecosystems.
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Affiliation(s)
- Zhou Li
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
| | - Philippe Juneau
- Department of Biological Sciences, GRIL-EcotoQ-TOXEN, Ecotoxicology of Aquatic Microorganisms Laboratory, Université du Québec à Montréal, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada;
| | - Yingli Lian
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
| | - Wei Zhang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
| | - Shanquan Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
| | - Cheng Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
| | - Longfei Shu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
| | - Qingyun Yan
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
- College of Agronomy, Hunan Agricultural University, Changsha 410128, Hunan, China
- Correspondence: (Z.H.); (K.X.)
| | - Kui Xu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou 510006, Guangdong, China; (Z.L.); (Y.L.); (W.Z.); (S.W.); (C.W.); (L.S.); (Q.Y.)
- Correspondence: (Z.H.); (K.X.)
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Einhardt AM, Ferreira S, Oliveira LM, Ribeiro DM, Rodrigues FÁ. Glyphosate and nickel differently affect photosynthesis and ethylene in glyphosate-resistant soybean plants infected by Phakopsora pachyrhizi. PHYSIOLOGIA PLANTARUM 2020; 170:592-606. [PMID: 32918487 DOI: 10.1111/ppl.13195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/29/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
Nickel (Ni) and glyphosate (Gl) are able to reduce the symptoms of Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, in soybean. However, their combined effects on the energy balance and ethylene metabolism of soybean plants infected with this fungus has not been elucidated. Therefore, the effects of Ni, Gl, and the combination of Ni + Gl on ASR development, photosynthetic capacity, sugar concentrations, and ethylene concentrations in plants of a Gl-resistant cultivar, uninfected or infected with P. pachyrhizi, were investigated. Inoculated plants supplied with Ni had the highest foliar Ni concentration in all the treatments. Gl had a negative effect on the foliar Ni concentration in Ni-sprayed plants. The ASR severity was reduced in plants sprayed with Ni and Gl. Carotenoid and chlorophyll concentrations were higher in inoculated Ni, Gl, and Ni + Gl plants than in control plants. Based on the chlorophyll a fluorescence parameters, the photosynthetic apparatus of the control inoculated plants was damaged, and the least amount of energy was directed to the photochemistry process in these plants. The reduced capacity of the photosynthetic mechanism to capture light and use the energy absorbed by photosystem II in inoculated plants was reflected in their reduced capacity to process CO2 , as indicated by the high internal CO2 concentrations and low rates of net carbon assimilation. The low sugar concentrations in inoculated plants from the control treatment were linked to their reduced photosynthetic capacity due to the high ASR severity. In uninfected plants, the ethylene concentration was not affected by Ni or Gl, while the ethylene concentration decreased in inoculated plants; this decrease was more pronounced in plants from the control treatment than in treated inoculated plants. In conclusion, this study sheds light on the role played by both Ni and Gl in ASR control from a physiological perspective. Soybean plants exposed to Ni and Gl were able to maintain high ethylene concentrations and photosynthetic capacity during the P. pachyrhizi infection process; as a result, these plants consumed less of their reserves than inoculated plants not treated with Ni or Gl.
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Affiliation(s)
- Andersom Milech Einhardt
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Laboratório da Interação Planta-Patógeno, Viçosa, 36570-900, Brazil
| | - Sandro Ferreira
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Laboratório da Interação Planta-Patógeno, Viçosa, 36570-900, Brazil
| | - Lillian Mathias Oliveira
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Laboratório da Interação Planta-Patógeno, Viçosa, 36570-900, Brazil
| | - Dimas Mendes Ribeiro
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, 36570-900, Brazil
| | - Fabrício Ávila Rodrigues
- Departamento de Fitopatologia, Universidade Federal de Viçosa, Laboratório da Interação Planta-Patógeno, Viçosa, 36570-900, Brazil
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Kodru S, Ur Rehman A, Vass I. Chloramphenicol enhances Photosystem II photodamage in intact cells of the cyanobacterium Synechocystis PCC 6803. PHOTOSYNTHESIS RESEARCH 2020; 145:227-235. [PMID: 32979144 PMCID: PMC7541379 DOI: 10.1007/s11120-020-00784-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
The effect of chloramphenicol, an often used protein synthesis inhibitor, in photosynthetic systems was studied on the rate of Photosystem II (PSII) photodamage in the cyanobacterium Synechocystis PCC 6803. Light-induced loss of PSII activity was compared in the presence of chloramphenicol and another protein synthesis inhibitor, lincomycin, by measuring the rate of oxygen evolution in Synechocystis 6803 cells. Our data show that the rate of PSII photodamage was significantly enhanced by chloramphenicol, at the usually applied 200 μg mL-1 concentration, relative to that obtained in the presence of lincomycin. Chloramphenicol-induced enhancement of photodamage has been observed earlier in isolated PSII membrane particles, and has been assigned to the damaging effect of chloramphenicol-mediated superoxide production (Rehman et al. 2016, Front Plant Sci 7:479). This effect points to the involvement of superoxide as damaging agent in the presence of chloramphenicol also in Synechocystis cells. The chloramphenicol-induced enhancement of photodamage was observed not only in wild-type Synechocystis 6803, which contains both Photosystem I (PSI) and PSII, but also in a PSI-less mutant which contains only PSII. Importantly, the rate of PSII photodamage was also enhanced by the absence of PSI when compared to that in the wild-type strain under all conditions studied here, i.e., without addition and in the presence of protein synthesis inhibitors. We conclude that chloramphenicol enhances photodamage mostly by its interaction with PSII, leading probably to superoxide production. The presence of PSI is also an important regulatory factor of PSII photodamage most likely via decreasing excitation pressure on PSII.
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Affiliation(s)
- Sandeesha Kodru
- Institute of Plant Biology, Biological Research Centre, Temesvari krt. 62, Szeged, 6726, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Ateeq Ur Rehman
- Institute of Plant Biology, Biological Research Centre, Temesvari krt. 62, Szeged, 6726, Hungary
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre, Temesvari krt. 62, Szeged, 6726, Hungary.
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Zavafer A, González-Solís A, Palacios-Bahena S, Saucedo-García M, Tapia de Aquino C, Vázquez-Santana S, King-Díaz B, Gavilanes-Ruiz M. Organized Disassembly of Photosynthesis During Programmed Cell Death Mediated By Long Chain Bases. Sci Rep 2020; 10:10360. [PMID: 32587330 PMCID: PMC7316715 DOI: 10.1038/s41598-020-65186-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 04/27/2020] [Indexed: 11/09/2022] Open
Abstract
In plants, pathogen triggered programmed cell death (PCD) is frequently mediated by polar lipid molecules referred as long chain bases (LCBs) or ceramides. PCD interceded by LCBs is a well-organized process where several cell organelles play important roles. In fact, light-dependent reactions in the chloroplast have been proposed as major players during PCD, however, the functional aspects of the chloroplast during PCD are largely unknown. For this reason, we investigated events that lead to disassembly of the chloroplast during PCD mediated by LCBs. To do so, LCB elevation was induced with Pseudomonas syringae pv. tomato (a non-host pathogen) or Fumonisin B1 in Phaseolus vulgaris. Then, we performed biochemical tests to detect PCD triggering events (phytosphingosine rises, MPK activation and H2O2 generation) followed by chloroplast structural and functional tests. Observations of the chloroplast, via optical phenotyping methods combined with microscopy, indicated that the loss of photosynthetic linear electron transport coincides with the organized ultrastructure disassembly. In addition, structural changes occurred in parallel with accumulation of H2O2 inside the chloroplast. These features revealed the collapse of chloroplast integrity and function as a mechanism leading to the irreversible execution of the PCD promoted by LCBs.
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Affiliation(s)
- Alonso Zavafer
- Climate Change Cluster, University of Technology Sydney, Faculty of Science Building 4, Level 6 Corner of Thomas and, Harris St, Ultimo NSW 2007, Sydney, Australia
| | - Ariadna González-Solís
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Silvia Palacios-Bahena
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Mariana Saucedo-García
- Instituto de Ciencias Agropecuarias, Universidad Autónoma del Estado de Hidalgo, Tulancingo, Hidalgo, México
| | - Cinthya Tapia de Aquino
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Sonia Vázquez-Santana
- Dpto. de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Beatriz King-Díaz
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México
| | - Marina Gavilanes-Ruiz
- Dpto. de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Ciudad de México, México.
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Lingvay M, Akhtar P, Sebők-Nagy K, Páli T, Lambrev PH. Photobleaching of Chlorophyll in Light-Harvesting Complex II Increases in Lipid Environment. FRONTIERS IN PLANT SCIENCE 2020; 11:849. [PMID: 32670321 PMCID: PMC7327537 DOI: 10.3389/fpls.2020.00849] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/26/2020] [Indexed: 05/18/2023]
Abstract
Excess light causes damage to the photosynthetic apparatus of plants and algae primarily via reactive oxygen species. Singlet oxygen can be formed by interaction of chlorophyll (Chl) triplet states, especially in the Photosystem II reaction center, with oxygen. Whether Chls in the light-harvesting antenna complexes play direct role in oxidative photodamage is less clear. In this work, light-induced photobleaching of Chls in the major trimeric light-harvesting complex II (LHCII) is investigated in different molecular environments - protein aggregates, embedded in detergent micelles or in reconstituted membranes (proteoliposomes). The effects of intense light treatment were analyzed by absorption and circular dichroism spectroscopy, steady-state and time-resolved fluorescence and EPR spectroscopy. The rate and quantum yield of photobleaching was estimated from the light-induced Chl absorption changes. Photobleaching occurred mainly in Chl a and was accompanied by strong fluorescence quenching of the remaining unbleached Chls. The rate of photobleaching increased by 140% when LHCII was embedded in lipid membranes, compared to detergent-solubilized LHCII. Removing oxygen from the medium or adding antioxidants largely suppressed the bleaching, confirming its oxidative mechanism. Singlet oxygen formation was monitored by EPR spectroscopy using spin traps and spin labels to detect singlet oxygen directly and indirectly, respectively. The quantum yield of Chl a photobleaching in membranes and detergent was found to be 3.4 × 10-5 and 1.4 × 10-5, respectively. These values compare well with the yields of ROS production estimated from spin-trap EPR spectroscopy (around 4 × 10-5 and 2 × 10-5). A kinetic model is proposed, quantifying the generation of Chl and carotenoid triplet states and singlet oxygen. The high quantum yield of photobleaching, especially in the lipid membrane, suggest that direct photodamage of the antenna occurs with rates relevant to photoinhibition in vivo. The results represent further evidence that the molecular environment of LHCII has profound impact on its functional characteristics, including, among others, the susceptibility to photodamage.
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Affiliation(s)
- Mónika Lingvay
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Doctoral School of Physics, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Parveen Akhtar
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | | | - Tibor Páli
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Petar H. Lambrev
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
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Ambastha V, Chauhan G, Tiwari BS, Tripathy BC. Execution of programmed cell death by singlet oxygen generated inside the chloroplasts of Arabidopsis thaliana. PROTOPLASMA 2020; 257:841-851. [PMID: 31909436 DOI: 10.1007/s00709-019-01467-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 12/04/2019] [Indexed: 06/10/2023]
Abstract
Absorption of excess excitation energy induces overproduction of singlet oxygen (1O2) in plants. The major sources of singlet oxygen production are chlorophyll and its intermediates located in the chloroplast. Over-accumulation of the chlorophyll biosynthetic intermediate protochlorophyllide by the exogenous application of 5-aminolevulinic acid (ALA), the precursor of tetrapyrrole, induced singlet oxygen production in the plastidic membranes. Over-expression of protochlorophyllide oxidoreductase C (PORC) in Arabidopsis thaliana resulted in efficient light-induced photo-transformation of protochlorophyllide to chlorophyllide that limited the accumulation of protochlorophyllide. Consequently, the 1O2 generation decreased in the PORC overexpressors (PORCx) and their cell death was minimal. Conversely, porC-2 over-accumulated protochlorophyllide in response to ALA treatment and generated higher amounts of 1O2 in light and had highest cell death as monitored by Evans blue staining. The protoplasts isolated from PORCx plants, when treated with ALA, generated minimal amounts of 1O2 as revealed by singlet oxygen sensor green (SOSG) fluorescence emission from chloroplasts. Conversely, the protoplasts of porC-2 mutants under identical conditions generated the maximum SOSG fluorescence in their chloroplasts and cytosol surrounding the chloroplasts most likely due to the leakage from the organelle. The membrane blebbing, a hallmark of programmed cell death, was clearly visible in WT and porC-2 protoplasts. Similarly, the nick end labelling (TUNEL) assay revealed nicks in the DNA. The TUNEL-positive nuclei after 30 min of light exposure were highest in porC-2 and lowest in PORCx protoplasts. The results demonstrate that higher amounts of singlet oxygen produced in the chloroplasts play an important role in programmed cell death.
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Affiliation(s)
- Vivek Ambastha
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Garima Chauhan
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Budhi Sagar Tiwari
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba, Gandhinagar, Gujarat, 382007, India
| | - Baishnab C Tripathy
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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30
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Tan SL, Yang YJ, Liu T, Zhang SB, Huang W. Responses of photosystem I compared with photosystem II to combination of heat stress and fluctuating light in tobacco leaves. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 292:110371. [PMID: 32005377 DOI: 10.1016/j.plantsci.2019.110371] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/02/2019] [Accepted: 12/07/2019] [Indexed: 05/02/2023]
Abstract
Moderate heat stress is usually accompanied with fluctuating light in summer. Although either heat stress or fluctuating light can cause photoinhibition of photosystems I and II (PSI and PSII), it is unclear whether moderate heat stress accelerate photoinhibition under fluctuating light. Here, we measured chlorophyll fluorescence, P700 redox state and the electrochromic shift signal under fluctuating light at 25 °C and 42 °C for tobacco leaves. We found that (1) the thylakoid proton conductance was significantly enhanced at 42 °C, leading to a decline in trans-thylakoid proton gradient (ΔpH); (2) this low ΔpH at 42 °C did not decrease donor-side limitation of PSI and thermal energy dissipation in PSII; (3) the activation of cyclic electron flow (CEF) around PSI was elevated at 42 °C; and (4) the moderate heat stress did not accelerate photoinhibition of PSI and PSII under fluctuating light. These results strongly indicate that under moderate heat stress the stimulation of CEF protects PSI under fluctuating light in tobacco leaves.
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Affiliation(s)
- Shun-Ling Tan
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tao Liu
- National Local Joint Engineering Research Center on Germplasm Utilization and Innovation of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, 650201, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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31
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Khorobrykh S, Havurinne V, Mattila H, Tyystjärvi E. Oxygen and ROS in Photosynthesis. PLANTS (BASEL, SWITZERLAND) 2020; 9:E91. [PMID: 31936893 PMCID: PMC7020446 DOI: 10.3390/plants9010091] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/29/2019] [Accepted: 01/02/2020] [Indexed: 12/14/2022]
Abstract
Oxygen is a natural acceptor of electrons in the respiratory pathway of aerobic organisms and in many other biochemical reactions. Aerobic metabolism is always associated with the formation of reactive oxygen species (ROS). ROS may damage biomolecules but are also involved in regulatory functions of photosynthetic organisms. This review presents the main properties of ROS, the formation of ROS in the photosynthetic electron transport chain and in the stroma of chloroplasts, and ROS scavenging systems of thylakoid membrane and stroma. Effects of ROS on the photosynthetic apparatus and their roles in redox signaling are discussed.
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Affiliation(s)
| | | | | | - Esa Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland or (S.K.); (V.H.); (H.M.)
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32
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Fang Y, Jiang Z, Zhao C, Li L, Ranvilage CIPM, Liu S, Wu Y, Huang X. Efficient Heat Dissipation and Cyclic Electron Flow Confer Daily Air Exposure Tolerance in the Intertidal Seagrass Halophila beccarii Asch. FRONTIERS IN PLANT SCIENCE 2020; 11:571627. [PMID: 33329629 PMCID: PMC7733926 DOI: 10.3389/fpls.2020.571627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/15/2020] [Indexed: 05/03/2023]
Abstract
Seagrasses inhabiting the intertidal zone experience periodically repeated cycles of air exposure and rehydration. However, little is known about the photoprotective mechanisms in photosystem (PS)II and PSI, as well as changes in carbon utilization upon air exposure. The photoprotective processes upon air exposure in Halophila beccarii Asch., an endangered seagrass species, were examined using the Dual-PAM-100 and non-invasive micro-test technology. The results showed that air exposure enhanced non-photochemical quenching (NPQ) in both PSII and PSI, with a maximum increase in NPQ and Y(ND) (which represents the fraction of overall P700 that is oxidized in a given state) of 23 and 57%, respectively, resulting in intensive thermal energy dissipation of excess optical energy. Moreover, cyclic electron transport driven by PSI (CEF) was upregulated, reflected by a 50 and 22% increase in CEF and maximum electron transport rate in PSI to compensate for the abolished linear electron transport with significant decreases in pmfLEF (the proton motive force [pmf]) attributable solely to proton translocation by linear electron flow [LEF]). Additionally, H+ fluxes in mesophyll cells decreased steadily with increased air exposure time, exhibiting a maximum decrease of six-fold, indicating air exposure modified carbon utilization by decreasing the proton pump influxes. These findings indicate that efficient heat dissipation and CEF confer daily air exposure tolerance to the intertidal seagrass H. beccarii and provide new insights into the photoprotective mechanisms of intertidal seagrasses. This study also helps explain the extensive distribution of H. beccarii in intertidal zones.
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Affiliation(s)
- Yang Fang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhijian Jiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- *Correspondence: Zhijian Jiang,
| | - Chunyu Zhao
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- College of Resources Environment and Planning, Dezhou University, Dezhou, China
| | - Linglan Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chanaka Isuranga Premarathne Maha Ranvilage
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Songlin Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
| | - Yunchao Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
| | - Xiaoping Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China
- Xiaoping Huang,
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Kato Y, Ohira A, Nagao R, Noguchi T. Does the water-oxidizing Mn4CaO5 cluster regulate the redox potential of the primary quinone electron acceptor QA in photosystem II? A study by Fourier transform infrared spectroelectrochemistry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:148082. [DOI: 10.1016/j.bbabio.2019.148082] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/31/2019] [Accepted: 09/08/2019] [Indexed: 10/25/2022]
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Huang W, Yang YJ, Wang JH, Hu H. Photorespiration is the major alternative electron sink under high light in alpine evergreen sclerophyllous Rhododendron species. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 289:110275. [PMID: 31623777 DOI: 10.1016/j.plantsci.2019.110275] [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: 06/10/2019] [Revised: 08/08/2019] [Accepted: 09/13/2019] [Indexed: 06/10/2023]
Abstract
Owing to the high leaf mass per area, alpine evergreen sclerophyllous Rhododendron have low values of mesophyll conductance (gm). The resulting low chloroplast CO2 concentration aggravates photorespiration, which requires a higher ATP/NADPH ratio. However, the significance of photorespiration and underlying mechanisms of energy balance in these species are little known. In this study, eight alpine evergreen sclerophyllous Rhododendron species grown in a common garden were tested for their gm, electron flow to photorespiration, and energy balancing. Under saturating light, gm was the most limiting factor for net photosynthesis (AN) in all species, and the species differences in AN were primarily driven by gm rather than stomatal conductance. The total electron flow through photosystem II (ETRII) nearly equaled the electron transport required for Rubisco carboxylation and oxygenation. Furthermore, blocking electron flow to photosystem I with appropriate inhibitors showed that electron flow to plastic terminal oxidase was not observed. As a result, these studied species showed little alternative electron flow mediated by water-water cycle or plastic terminal oxidase. By comparison, the ratio of electron transport consumed by photorespiration to ETRII (JPR/ETRII), ranging from 43%∼55%, was negatively correlated to AN and gm. Furthermore, the increased ATP production required by enhanced photorespiration was regulated by cyclic electron flow around photosystem I. These results indicate that photorespiration is the major electron sink for dissipation of excess excitation energy in the alpine evergreen sclerophyllous Rhododendron species. The coordination of gm, photorespiration and cyclic electron flow is important for sustaining leaf photosynthesis.
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Affiliation(s)
- Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, PR China
| | - Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Ji-Hua Wang
- Flower Research Institute of Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, PR China.
| | - Hong Hu
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, PR China.
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35
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Zhang MM, Fan DY, Murakami K, Badger MR, Sun GY, Chow WS. Partially Dissecting Electron Fluxes in Both Photosystems in Spinach Leaf Disks during Photosynthetic Induction. PLANT & CELL PHYSIOLOGY 2019; 60:2206-2219. [PMID: 31271439 DOI: 10.1093/pcp/pcz114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 05/29/2019] [Indexed: 06/09/2023]
Abstract
Photosynthetic induction, a gradual increase in photosynthetic rate on a transition from darkness or low light to high light, has ecological significance, impact on biomass accumulation in fluctuating light and relevance to photoprotection in strong light. However, the experimental quantification of the component electron fluxes in and around both photosystems during induction has been rare. Combining optimized chlorophyll fluorescence, the redox kinetics of P700 [primary electron donor in Photosystem I (PSI)] and membrane inlet mass spectrometry in the absence/presence of inhibitors/mediator, we partially estimated the components of electron fluxes in spinach leaf disks on transition from darkness to 1,000 �mol photons�m-2�s-1 for up to 10 min, obtaining the following findings: (i) the partitioning of energy between both photosystems did not change noticeably; (ii) in Photosystem II (PSII), the combined cyclic electron flow (CEF2) and charge recombination (CR2) to the ground state decreased gradually toward 0 in steady state; (iii) oxygen reduction by electrons from PSII, partly bypassing PSI, was small but measurable; (iv) cyclic electron flow around PSI (CEF1) peaked before becoming somewhat steady; (v) peak magnitudes of some of the electron fluxes, all probably photoprotective, were in the descending order: CEF1 > CEF2 + CR2 > chloroplast O2 uptake; and (vi) the chloroplast NADH dehydrogenase-like complex appeared to aid the antimycin A-sensitive CEF1. The results are important for fine-tuning in silico simulation of in vivo photosynthetic electron transport processes; such simulation is, in turn, necessary to probe partial processes in a complex network of interactions in response to environmental changes.
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Affiliation(s)
- Meng-Meng Zhang
- Department of Plant Physiology, College of Life Science, Northeast Forestry University, Harbin, Heilongjiang, China
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Da-Yong Fan
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, Australia
- College of Forestry, Beijing Forestry University, Beijing, China
| | - Keach Murakami
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, Australia
- National Agriculture and Food Research Organization (NARO), Hokkaido Agricultural Research Center (HARC), Hitsujigaoka 1, Toyohira, Sapporo, Japan
| | - Murray R Badger
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Guang-Yu Sun
- Department of Plant Physiology, College of Life Science, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Wah Soon Chow
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Acton, ACT, Australia
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D1:Glu244 and D1:Tyr246 of the bicarbonate-binding environment of Photosystem II moderate high light susceptibility and electron transfer through the quinone-Fe-acceptor complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:148054. [DOI: 10.1016/j.bbabio.2019.07.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 07/12/2019] [Accepted: 07/18/2019] [Indexed: 12/29/2022]
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D'Alessandro S, Havaux M. Sensing β-carotene oxidation in photosystem II to master plant stress tolerance. THE NEW PHYTOLOGIST 2019; 223:1776-1783. [PMID: 31090944 DOI: 10.1111/nph.15924] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 05/08/2019] [Indexed: 05/21/2023]
Abstract
Stressful environmental conditions lead to the production of reactive oxygen species in the chloroplasts, due to limited photosynthesis and enhanced excitation pressure on the photosystems. Among these reactive species, singlet oxygen (1 O2 ), which is generated at the level of the PSII reaction center, is very reactive, readily oxidizing macromolecules in its immediate surroundings, and it has been identified as the principal cause of photooxidative damage in plant leaves. The two β-carotene molecules present in the PSII reaction center are prime targets of 1 O2 oxidation, leading to the formation of various oxidized derivatives. Plants have evolved sensing mechanisms for those PSII-generated metabolites, which regulate gene expression, putting in place defense mechanisms and alleviating the effects of PSII-damaging conditions. A new picture is thus emerging which places PSII as a sensor and transducer in plant stress resilience through its capacity to generate signaling metabolites under excess light energy. This review summarizes new advances in the characterization of the apocarotenoids involved in the PSII-mediated stress response and of the pathways elicited by these molecules, among which is the xenobiotic detoxification.
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Affiliation(s)
- Stefano D'Alessandro
- CEA, CNRS, UMR 7265, Institut Biosciences et Biotechnologies d'Aix-Marseille, CEA/Cadarache, Aix-Marseille University, Saint-Paul-lez-Durance, France
| | - Michel Havaux
- CEA, CNRS, UMR 7265, Institut Biosciences et Biotechnologies d'Aix-Marseille, CEA/Cadarache, Aix-Marseille University, Saint-Paul-lez-Durance, France
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Kaňa R, Kotabová E, Šedivá B, Kuthanová Trsková E. Photoprotective strategies in the motile cryptophyte alga Rhodomonas salina-role of non-photochemical quenching, ions, photoinhibition, and cell motility. Folia Microbiol (Praha) 2019; 64:691-703. [PMID: 31352667 DOI: 10.1007/s12223-019-00742-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022]
Abstract
We explored photoprotective strategies in a cryptophyte alga Rhodomonas salina. This cryptophytic alga represents phototrophs where chlorophyll a/c antennas in thylakoids are combined with additional light-harvesting system formed by phycobiliproteins in the chloroplast lumen. The fastest response to excessive irradiation is induction of non-photochemical quenching (NPQ). The maximal NPQ appears already after 20 s of excessive irradiation. This initial phase of NPQ is sensitive to Ca2+ channel inhibitor (diltiazem) and disappears, also, in the presence of non-actin, an ionophore for monovalent cations. The prolonged exposure to high light of R. salina cells causes photoinhibition of photosystem II (PSII) that can be further enhanced when Ca2+ fluxes are inhibited by diltiazem. The light-induced reduction in PSII photochemical activity is smaller when compared with immotile diatom Phaeodactylum tricornutum. We explain this as a result of their different photoprotective strategies. Besides the protective role of NPQ, the motile R. salina also minimizes high light exposure by increased cell velocity by almost 25% percent (25% from 82 to 104 μm/s). We suggest that motility of algal cells might have a photoprotective role at high light because algal cell rotation around longitudinal axes changes continual irradiation to periodically fluctuating light.
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Affiliation(s)
- Radek Kaňa
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic.
| | - Eva Kotabová
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic
| | - Barbora Šedivá
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic
| | - Eliška Kuthanová Trsková
- Institute of Microbiology, Centre ALGATECH, Czech Academy of Sciences, Třeboň, Czech Republic.,Student of Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, Ceske Budejovice, Czech Republic
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Chen J, Chen J, Liu Y, Zheng Y, Zhu Q, Han G, Shen JR. Proton-Coupled Electron Transfer of Plastoquinone Redox Reactions in Photosystem II: A Pump-Probe Ultraviolet Resonance Raman Study. J Phys Chem Lett 2019; 10:3240-3247. [PMID: 31117681 DOI: 10.1021/acs.jpclett.9b00959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Plastoquinones (PQs) act as electron and proton mediators in photosystem II (PSII) for solar-to-chemical energy conversion. It is known that the redox potential of PQ varies in a wide range spanning hundreds of millivolts; however, its structural origin is not known yet. Here, by developing a pump-probe ultraviolet resonance Raman technique, we measured the vibrational structures of PQs including QA and QB in cyanobacterial PSII directly. The conversion of QA to QA•- in the Mn-depleted PSII is verified by direct observation of the distinct QA•- vibrational bands. A frequency upshift of the ring C=O/C=C stretch band at 1565 cm-1 for QA•- was observed, which suggests a π-π interaction between the quinone ring and Trp253. In contrast, proton-coupled reduction of QA to QAH upon light-driven electron transfer is demonstrated in PSII without QB bound. The H-bond between QA and His214 is likely the proton origin of this proton-coupled electron transfer.
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Affiliation(s)
- Jun Chen
- Science and Technology on Surface Physics and Chemistry Laboratory , Jiangyou 621908 , China
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Jinfan Chen
- Science and Technology on Surface Physics and Chemistry Laboratory , Jiangyou 621908 , China
| | - Ying Liu
- Institute of Materials , China Academy of Engineering Physics , Mianyang 621907 , China
| | - Yang Zheng
- State Key Laboratory of Catalysis , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , China
| | - Qingjun Zhu
- Photosynthesis Research Center, Key Laboratory of Photobiology , Institute of Botany, Chinese Academy of Sciences , No. 20, Nanxincun , Xiangshan, Beijing , 100093 , China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology , Institute of Botany, Chinese Academy of Sciences , No. 20, Nanxincun , Xiangshan, Beijing , 100093 , China
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology , Institute of Botany, Chinese Academy of Sciences , No. 20, Nanxincun , Xiangshan, Beijing , 100093 , China
- Research Institute of Interdisciplinary Science, Graduate School of Natural Science and Technology , Okayama University , Tsushima Naka 3-1-1 , Okayama 700-8530 , Japan
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Light Energy Partitioning under Various Environmental Stresses Combined with Elevated CO2 in Three Deciduous Broadleaf Tree Species in Japan. CLIMATE 2019. [DOI: 10.3390/cli7060079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Understanding plant response to excessive light energy not consumed by photosynthesis under various environmental stresses, would be important for maintaining biosphere sustainability. Based on previous studies regarding nitrogen (N) limitation, drought in Japanese white birch (Betula platyphylla var. japonica), and elevated O3 in Japanese oak (Quercus mongolica var. crispula) and Konara oak (Q. serrata) under future-coming elevated CO2 concentrations, we newly analyze the fate of absorbed light energy by a leaf, partitioning into photochemical processes, including photosynthesis, photorespiration and regulated and non-regulated, non-photochemical quenchings. No significant increases in the rate of non-regulated non-photochemical quenching (JNO) were observed in plants grown under N limitation, drought and elevated O3 in ambient or elevated CO2. This suggests that the risk of photodamage caused by excessive light energy was not increased by environmental stresses reducing photosynthesis, irrespective of CO2 concentrations. The rate of regulated non-photochemical quenching (JNPQ), which contributes to regulating photoprotective thermal dissipation, could well compensate decreases in the photosynthetic electron transport rate through photosystem II (JPSII) under various environmental stresses, since JNPQ+JPSII was constant across the treatment combinations. It is noteworthy that even decreases in JNO were observed under N limitation and elevated O3, irrespective of CO2 conditions, which may denote a preconditioning-mode adaptive response for protection against further stress. Such an adaptive response may not fully compensate for the negative effects of lethal stress, but may be critical for coping with non-lethal stress and regulating homeostasis. Regarding the three deciduous broadleaf tree species, elevated CO2 appears not to influence the plant responses to environmental stresses from the viewpoint of susceptibility to photodamage.
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Du J, Qiu B, Pedrosa Gomes M, Juneau P, Dai G. Influence of light intensity on cadmium uptake and toxicity in the cyanobacteria Synechocystis sp. PCC6803. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 211:163-172. [PMID: 30991162 DOI: 10.1016/j.aquatox.2019.03.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 03/18/2019] [Accepted: 03/24/2019] [Indexed: 05/02/2023]
Abstract
The mechanisms of cadmium toxicity to cyanobacterial photosynthesis have been extensively studied, but the response mechanisms to combinations of different cadmium concentrations and different light intensities are not yet well understood. The two principal objectives of the present work were to: 1) study the short term (5 h) toxic effects of cadmium on Synechocystis PCC6803 under three different culturing light intensity conditions; and, 2) investigate the effects of light history on Cd toxicity to Synechocystis. The maximal (ФM) and operational (Ф'M) photosystem II quantum yields, photosystem I quantum yield [Y (I)], cyclic electron flow, relative photochemical quenching (qPrel), relative non-photochemical quenching (qNrel), relative unquenched fluorescence (UQFrel), pigment contents, and cadmium uptake were evaluated when Synechocystis cells were treated with cadmium for 5 h under three different light conditions. We demonstrated that cadmium toxicity was enhanced with increasing growth light intensities due to increased cadmium uptake under higher light exposures, and the photoprotective mechanisms could not cope with cadmium and light stress under high light conditions. We also investigated Cd toxicity to Synechocystis adapted to three growth light intensities and subsequently shifted to different light intensity conditions to compare the effects of light regime shift on cadmium toxicity. We observed increased cadmium toxicity when the cells were transferred from low light to high light conditions. Interestingly, Synechocystis cells grown at high light intensities were more tolerant to cadmium than cells grown at low light intensities after the same light regime shift, due to the development of photoprotective mechanisms.
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Affiliation(s)
- Juan Du
- College of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, PR China
| | - Baosheng Qiu
- College of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, PR China
| | - Marcelo Pedrosa Gomes
- Laboratório de Fisiologia de Plantas sob Estresse, Departamento de Botânica, Setor de Ciências Biológicas, Universidade Federal do Paraná, Avenida Coronel Francisco H. dos Santos, 100, Centro Politécnico Jardim das Américas, C.P. 19031, 81531-980, Curitiba, Paraná, Brazil
| | - Philippe Juneau
- Departement des Sciences Biologiques - GRIL-TOXEN, Ecotoxicology of Aquatic Microorganisms Laboratory, Université du Québec à Montréal, Succ. Centre-Ville, C.P. 8888, H3C 3P8, Montréal, Québec, Canada.
| | - Guozheng Dai
- College of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, PR China.
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42
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Shevela D, Ananyev G, Vatland AK, Arnold J, Mamedov F, Eichacker LA, Dismukes GC, Messinger J. 'Birth defects' of photosystem II make it highly susceptible to photodamage during chloroplast biogenesis. PHYSIOLOGIA PLANTARUM 2019; 166:165-180. [PMID: 30693529 DOI: 10.1111/ppl.12932] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/17/2019] [Accepted: 01/18/2019] [Indexed: 06/09/2023]
Abstract
High solar flux is known to diminish photosynthetic growth rates, reducing biomass productivity and lowering disease tolerance. Photosystem II (PSII) of plants is susceptible to photodamage (also known as photoinactivation) in strong light, resulting in severe loss of water oxidation capacity and destruction of the water-oxidizing complex (WOC). The repair of damaged PSIIs comes at a high energy cost and requires de novo biosynthesis of damaged PSII subunits, reassembly of the WOC inorganic cofactors and membrane remodeling. Employing membrane-inlet mass spectrometry and O2 -polarography under flashing light conditions, we demonstrate that newly synthesized PSII complexes are far more susceptible to photodamage than are mature PSII complexes. We examined these 'PSII birth defects' in barley seedlings and plastids (etiochloroplasts and chloroplasts) isolated at various times during de-etiolation as chloroplast development begins and matures in synchronization with thylakoid membrane biogenesis and grana membrane formation. We show that the degree of PSII photodamage decreases simultaneously with biogenesis of the PSII turnover efficiency measured by O2 -polarography, and with grana membrane stacking, as determined by electron microscopy. Our data from fluorescence, QB -inhibitor binding, and thermoluminescence studies indicate that the decline of the high-light susceptibility of PSII to photodamage is coincident with appearance of electron transfer capability QA - → QB during de-etiolation. This rate depends in turn on the downstream clearing of electrons upon buildup of the complete linear electron transfer chain and the formation of stacked grana membranes capable of longer-range energy transfer.
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Affiliation(s)
- Dmitry Shevela
- Department of Chemistry, Chemical Biological Centre, Umeå University, S-90187, Umeå, Sweden
| | - Gennady Ananyev
- The Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Ann K Vatland
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, N-4036, Stavanger, Norway
| | - Janine Arnold
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, N-4036, Stavanger, Norway
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, S-75237, Uppsala, Sweden
| | - Lutz A Eichacker
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, N-4036, Stavanger, Norway
| | - G Charles Dismukes
- The Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, 08854, USA
| | - Johannes Messinger
- Department of Chemistry, Chemical Biological Centre, Umeå University, S-90187, Umeå, Sweden
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, S-75237, Uppsala, Sweden
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Zhao D, Yu Y, Shen Y, Liu Q, Zhao Z, Sharma R, Reiter RJ. Melatonin Synthesis and Function: Evolutionary History in Animals and Plants. Front Endocrinol (Lausanne) 2019; 10:249. [PMID: 31057485 PMCID: PMC6481276 DOI: 10.3389/fendo.2019.00249] [Citation(s) in RCA: 296] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/29/2019] [Indexed: 12/12/2022] Open
Abstract
Melatonin is an ancient molecule that can be traced back to the origin of life. Melatonin's initial function was likely that as a free radical scavenger. Melatonin presumably evolved in bacteria; it has been measured in both α-proteobacteria and in photosynthetic cyanobacteria. In early evolution, bacteria were phagocytosed by primitive eukaryotes for their nutrient value. According to the endosymbiotic theory, the ingested bacteria eventually developed a symbiotic association with their host eukaryotes. The ingested α-proteobacteria evolved into mitochondria while cyanobacteria became chloroplasts and both organelles retained their ability to produce melatonin. Since these organelles have persisted to the present day, all species that ever existed or currently exist may have or may continue to synthesize melatonin in their mitochondria (animals and plants) and chloroplasts (plants) where it functions as an antioxidant. Melatonin's other functions, including its multiple receptors, developed later in evolution. In present day animals, via receptor-mediated means, melatonin functions in the regulation of sleep, modulation of circadian rhythms, enhancement of immunity, as a multifunctional oncostatic agent, etc., while retaining its ability to reduce oxidative stress by processes that are, in part, receptor-independent. In plants, melatonin continues to function in reducing oxidative stress as well as in promoting seed germination and growth, improving stress resistance, stimulating the immune system and modulating circadian rhythms; a single melatonin receptor has been identified in land plants where it controls stomatal closure on leaves. The melatonin synthetic pathway varies somewhat between plants and animals. The amino acid, tryptophan, is the necessary precursor of melatonin in all taxa. In animals, tryptophan is initially hydroxylated to 5-hydroxytryptophan which is then decarboxylated with the formation of serotonin. Serotonin is either acetylated to N-acetylserotonin or it is methylated to form 5-methoxytryptamine; these products are either methylated or acetylated, respectively, to produce melatonin. In plants, tryptophan is first decarboxylated to tryptamine which is then hydroxylated to form serotonin.
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Affiliation(s)
- Dake Zhao
- Biocontrol Engineering Research Center of Plant Disease and Pest, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Crop Disease and Pest, Yunnan University, Kunming, China
- School of Life Science, Yunnan University, Kunming, China
| | - Yang Yu
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan University, Kunming, China
| | - Yong Shen
- College of Agriculture and Biotechnology, Yunnan Agricultural University, Kunming, China
| | - Qin Liu
- School of Landscape and Horticulture, Yunnan Vocational and Technical College of Agriculture, Kunming, China
| | - Zhiwei Zhao
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan University, Kunming, China
| | - Ramaswamy Sharma
- Department of Cell Systems and Anatomy, The University of Texas Health Science Center at San Antonio (UT Health), San Antonio, TX, United States
| | - Russel J. Reiter
- Department of Cell Systems and Anatomy, The University of Texas Health Science Center at San Antonio (UT Health), San Antonio, TX, United States
- *Correspondence: Russel J. Reiter
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Kosugi M, Maruo F, Inoue T, Kurosawa N, Kawamata A, Koike H, Kamei Y, Kudoh S, Imura S. A comparative study of wavelength-dependent photoinactivation in photosystem II of drought-tolerant photosynthetic organisms in Antarctica and the potential risks of photoinhibition in the habitat. ANNALS OF BOTANY 2018; 122:1263-1278. [PMID: 30052754 PMCID: PMC6324753 DOI: 10.1093/aob/mcy139] [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: 03/12/2018] [Accepted: 07/16/2018] [Indexed: 05/22/2023]
Abstract
BACKGROUND AND AIMS All photosynthetic organisms are faced with photoinhibition, which would lead to death in severe environments. Because light quality and light intensity fluctuate dynamically in natural microenvironments, quantitative and qualitative analysis of photoinhibition is important to clarify how this environmental pressure has impacted ecological behaviour in different organisms. METHODS We evaluated the wavelength dependency of photoinactivation to photosystem II (PSII) of Prasiola crispa (green alga), Umbilicaria decussata (lichen) and Ceratodon purpureus (bryophyte) harvested from East Antarctica. For evaluation, we calculated reaction coefficients, Epis, of PSII photoinactivation against energy dose using a large spectrograph. Daily fluctuation of the rate coefficient of photoinactivation, kpi, was estimated from Epis and ambient light spectra measured during the summer season. KEY RESULTS Wavelength dependency of PSII photoinactivation was different for the three species, although they form colonies in close proximity to each other in Antarctica. The lichen exhibited substantial resistance to photoinactivation at all wavelengths, while the bryophyte showed sensitivity only to UV-B light (<325 nm). On the other hand, the green alga, P. crispa, showed ten times higher Epi to UV-B light than the bryophyte. It was much more sensitive to UV-A (325-400 nm). The risk of photoinhibition fluctuated considerably throughout the day. On the other hand, Epis were reduced dramatically for dehydrated compared with hydrated P. crispa. CONCLUSIONS The deduced rate coefficients of photoinactivation under ambient sunlight suggested that P. crispa needs to pay a greater cost to recover from photodamage than the lichen or the bryophyte in order to keep sufficient photosynthetic activity under the Antarctic habitat. A newly identified drought-induced protection mechanism appears to operate in P. crispa, and it plays a critical role in preventing the oxygen-evolving complex from photoinactivation when the repair cycle is inhibited by dehydration.
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Affiliation(s)
- Makiko Kosugi
- National Institute of Polar Research, Research Organization of Information and Systems, Tachikawa, Tokyo, Japan
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Bunkyo-ku, Tokyo, Japan
- For correspondence. E-mail:
| | - Fumino Maruo
- Department of Polar Science, School of Multidisciplinary Science, SOKENDAI (The Graduate University for Advanced Studies), Tachikawa, Tokyo, Japan
| | - Takeshi Inoue
- Department of Polar Science, School of Multidisciplinary Science, SOKENDAI (The Graduate University for Advanced Studies), Tachikawa, Tokyo, Japan
| | - Norio Kurosawa
- Department of Science and Engineering for Sustainable Innovation, Faculty of Science and Engineering, Soka University, Hachioji, Tokyo, Japan
| | - Akinori Kawamata
- Nature Research Group, Ehime Prefectural Science Museum, Ehime, Japan
| | - Hiroyuki Koike
- Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Bunkyo-ku, Tokyo, Japan
| | - Yasuhiro Kamei
- Department of Basic Biology, School of Life Sciences, SOKENDAI (The Graduate University for Advanced Studies), Myodaiji, Okazaki, Aichi, Japan
- National Institute for Basic Biology, National Institutes of Natural Sciences, Myodaiji, Okazaki, Japan
| | - Sakae Kudoh
- National Institute of Polar Research, Research Organization of Information and Systems, Tachikawa, Tokyo, Japan
- Department of Polar Science, School of Multidisciplinary Science, SOKENDAI (The Graduate University for Advanced Studies), Tachikawa, Tokyo, Japan
| | - Satoshi Imura
- National Institute of Polar Research, Research Organization of Information and Systems, Tachikawa, Tokyo, Japan
- Department of Polar Science, School of Multidisciplinary Science, SOKENDAI (The Graduate University for Advanced Studies), Tachikawa, Tokyo, Japan
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Meravi N, Kumar Prajapati S. Seasonal variation in chlorophyll a fluorescence of Butea monosperma. BIOL RHYTHM RES 2018. [DOI: 10.1080/09291016.2018.1557852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Neelima Meravi
- Department of Botany, School of Life Sciences, Guru Ghasidas Vishwavidyalaya, Bilaspur, India
| | - Santosh Kumar Prajapati
- Department of Botany, School of Life Sciences, Guru Ghasidas Vishwavidyalaya, Bilaspur, India
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Hughes DJ, Campbell DA, Doblin MA, Kromkamp JC, Lawrenz E, Moore CM, Oxborough K, Prášil O, Ralph PJ, Alvarez MF, Suggett DJ. Roadmaps and Detours: Active Chlorophyll- a Assessments of Primary Productivity Across Marine and Freshwater Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:12039-12054. [PMID: 30247887 DOI: 10.1021/acs.est.8b03488] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Assessing phytoplankton productivity over space and time remains a core goal for oceanographers and limnologists. Fast Repetition Rate fluorometry (FRRf) provides a potential means to realize this goal with unprecedented resolution and scale yet has not become the "go-to" method despite high expectations. A major obstacle is difficulty converting electron transfer rates to equivalent rates of C-fixation most relevant for studies of biogeochemical C-fluxes. Such difficulty stems from methodological inconsistencies and our limited understanding of how the electron requirement for C-fixation (Φe,C) is influenced by the environment and by differences in the composition and physiology of phytoplankton assemblages. We outline a "roadmap" for limiting methodological bias and to develop a more mechanistic understanding of the ecophysiology underlying Φe,C. We 1) re-evaluate core physiological processes governing how microalgae invest photosynthetic electron transport-derived energy and reductant into stored carbon versus alternative sinks. Then, we 2) outline steps to facilitate broader uptake and exploitation of FRRf, which could transform our knowledge of aquatic primary productivity. We argue it is time to 3) revise our historic methodological focus on carbon as the currency of choice, to 4) better appreciate that electron transport fundamentally drives ecosystem biogeochemistry, modulates cell-to-cell interactions, and ultimately modifies community biomass and structure.
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Affiliation(s)
- David J Hughes
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
| | - Douglas A Campbell
- Department of Biology , Mount Allison University , Sackville , New Brunswick E4L 1E4 , Canada
| | - Martina A Doblin
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
| | - Jacco C Kromkamp
- Department of Estuarine and Delta Systems , NIOZ Royal Netherlands Institute for Sea Research and Utrecht University , P.O. Box 140, 4401 NT Yerseke , The Netherlands
| | - Evelyn Lawrenz
- Centre Algatech , Institute of Microbiology, Czech Academy of Sciences , Třeboň 379 81 , Czech Republic
| | - C Mark Moore
- Ocean and Earth Science , University of Southampton, National Oceanography Centre, Southampton , European Way , Southampton SO14 3ZH , U.K
| | | | - Ondřej Prášil
- Centre Algatech , Institute of Microbiology, Czech Academy of Sciences , Třeboň 379 81 , Czech Republic
| | - Peter J Ralph
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
| | - Marco F Alvarez
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
| | - David J Suggett
- Climate Change Cluster , University of Technology Sydney , Ultimo, Sydney 2007 , New South Wales , Australia
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Huang W, Suorsa M, Zhang SB. In vivo regulation of thylakoid proton motive force in immature leaves. PHOTOSYNTHESIS RESEARCH 2018; 138:207-218. [PMID: 30056561 DOI: 10.1007/s11120-018-0565-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/24/2018] [Indexed: 06/08/2023]
Abstract
In chloroplast, proton motive force (pmf) is critical for ATP synthesis and photoprotection. To prevent photoinhibition of photosynthetic apparatus, proton gradient (ΔpH) across the thylakoid membranes needs to be built up to minimize the production of reactive oxygen species (ROS) in thylakoid membranes. However, the regulation of thylakoid pmf in immature leaves is little known. In this study, we compared photosynthetic electron sinks, P700 redox state, non-photochemical quenching (NPQ), and electrochromic shift (ECS) signal in immature and mature leaves of a cultivar of Camellia. The immature leaves displayed lower linear electron flow and cyclic electron flow, but higher levels of NPQ and P700 oxidation ratio under high light. Meanwhile, we found that pmf and ΔpH were higher in the immature leaves. Furthermore, the immature leaves showed significantly lower thylakoid proton conductivity than mature leaves. These results strongly indicated that immature leaves can build up enough ΔpH by modulating proton efflux from the lumenal side to the stromal side of thylakoid membranes, which is essential to prevent photoinhibition via thermal energy dissipation and photosynthetic control of electron transfer. This study highlights that the activity of chloroplast ATP synthase is a key safety valve for photoprotection in immature leaves.
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Affiliation(s)
- Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China.
| | | | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
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48
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Meravi N, Prajapati SK. Temporal variation in chlorophyll fluorescence of different tree species. BIOL RHYTHM RES 2018. [DOI: 10.1080/09291016.2018.1528694] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Neelima Meravi
- Department of Botany, School of Life Sciences, Guru Ghasidas Vishwavidyalaya, Bilaspur, India
| | - Santosh Kumar Prajapati
- Department of Botany, School of Life Sciences, Guru Ghasidas Vishwavidyalaya, Bilaspur, India
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Huang W, Tikkanen M, Cai YF, Wang JH, Zhang SB. Chloroplastic ATP synthase optimizes the trade-off between photosynthetic CO2 assimilation and photoprotection during leaf maturation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:1067-1074. [DOI: 10.1016/j.bbabio.2018.06.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/03/2018] [Accepted: 06/08/2018] [Indexed: 11/24/2022]
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50
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Wieners PC, Mudimu O, Bilger W. Survey of the occurrence of desiccation-induced quenching of basal fluorescence in 28 species of green microalgae. PLANTA 2018; 248:601-612. [PMID: 29846774 DOI: 10.1007/s00425-018-2925-7] [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: 12/19/2017] [Accepted: 05/22/2018] [Indexed: 06/08/2023]
Abstract
Desiccation-induced chlorophyll fluorescence quenching seems to be an indispensable part of desiccation resistance in the surveyed 28 green microalgal species. Lichens are desiccation tolerant meta-organisms. In the desiccated state photosynthesis is inhibited rendering the photobionts potentially sensitive to photoinhibition. As a photoprotective mechanism, strong non-radiative dissipation of absorbed light leading to quenching of chlorophyll fluorescence has been proposed. Desiccation-induced quenching affects not only variable fluorescence, but also the so-called basal fluorescence, F0. This phenomenon is well-known for intact lichens and some free living aero-terrestrial algae, but it was often absent in isolated lichen algae. Therefore, a thorough screening for the appearance of desiccation-induced quenching was undertaken with 13 different aero-terrestrial microalgal species and lichen photobionts. They were compared with 15 aquatic green microalgal species, among them also three marine species. We asked the following questions: Do isolated lichen algae show desiccation-induced quenching? Are aero-terrestrial algae different in this respect to aquatic algae and is the potential for desiccation-induced quenching coupled to desiccation tolerance? How variable is desiccation-induced quenching among species? Most of the aero-terrestrial algae, including all lichen photobionts, showed desiccation-induced quenching, although highly variable in extent, whereas most of the aquatic algae did not. All algae displaying quenching were also desiccation tolerant, whereas all algae unable to perform desiccation-induced quenching were desiccation intolerant. Desiccation-induced fluorescence quenching seems to be an indispensable part of desiccation resistance in the investigated species.
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Affiliation(s)
- Paul Christian Wieners
- Botanical Institute, Christian-Albrechts University of Kiel, Olshausenstraße 40, DE, 24098, Kiel, Germany.
| | - Opayi Mudimu
- Botanical Institute, Christian-Albrechts University of Kiel, Olshausenstraße 40, DE, 24098, Kiel, Germany
| | - Wolfgang Bilger
- Botanical Institute, Christian-Albrechts University of Kiel, Olshausenstraße 40, DE, 24098, Kiel, Germany
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