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Zhu Y, Wang H, Xiang X, Hayat K, Wu R, Tian J, Zheng H, Xie M, Li B, Du S. A dose-dependent effect of UV-328 on photosynthesis: Exploring light harvesting and UV-B sensing mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134670. [PMID: 38781858 DOI: 10.1016/j.jhazmat.2024.134670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/27/2024] [Accepted: 05/19/2024] [Indexed: 05/25/2024]
Abstract
Benzotriazole ultraviolet (UV) stabilizers (BUVs) have emerged as significant environmental contaminants, frequently detected in various ecosystems. While the toxicity of BUVs to aquatic organisms is well-documented, studies on their impact on plant life are scarce. Plants are crucial as they provide the primary source of energy and organic matter in ecosystems through photosynthesis. This study investigated the effects of UV-328 (2-(2-hydroxy-4',6'-di-tert-amylphenyl) benzotriazole) on plant growth indices and photosynthesis processes, employing conventional physiological experiments, RNA sequencing (RNA-seq) analysis, and computational methods. Results demonstrated a biphasic response in plant biomass and the maximum quantum yield of PS II (Fv/Fm), showing improvement at a 50 μM UV-328 treatment but reduction under 150 μM UV-328 exposure. Additionally, disruption in thylakoid morphology was observed at the higher concentration. RNA-seq and qRT-PCR analysis identified key differentially expressed genes (light-harvesting chlorophyll-protein complex Ⅰ subunit A4, light-harvesting chlorophyll b-binding protein 3, UVR8, and curvature thylakoid 1 A) related to photosynthetic light harvesting, UV-B sensing, and chloroplast structure pathways, suggesting they may contribute to the observed alterations in photosynthesis activity induced by UV-328 exposure. Molecular docking analyses further supported the binding affinity between these proteins and UV-328. Overall, this study provided comprehensive physiological and molecular insights, contributing valuable information to the evaluation of the potential risks posed by UV-328 to critical plant physiological processes.
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Affiliation(s)
- Yaxin Zhu
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Hua Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Xiaobo Xiang
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Kashif Hayat
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Ran Wu
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Jiaying Tian
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Haoyi Zheng
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Minghui Xie
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Beier Li
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Shaoting Du
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China.
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Yokono M, Noda C, Minagawa J. Spillover in the direct-type PSI-PSII megacomplex isolated from Arabidopsis thaliana is regulated by pH. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149012. [PMID: 37704004 DOI: 10.1016/j.bbabio.2023.149012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 09/03/2023] [Indexed: 09/15/2023]
Abstract
Various megacomplexes in which Photosystem I and Photosystem II are physically bound (PSI-PSII m.c.) have been found in many organisms. In terms of function, these can be divided into two groups: those in which PSII and PSI are closely coupled (direct-type, photoprotection), and those in which a large light-harvesting antenna is placed between PSII and PSI (bridged-type, energy sharing). Arabidopsis thaliana has been reported to use the direct-type, where fast energy transfer occurs from PSII to PSI (~20 ps, fast spillover). In this paper, we show that the fast spillover is reversibly regulated depending on pH.
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Affiliation(s)
- Makio Yokono
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Japan; Basic Biology Program, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Japan.
| | - Chiyo Noda
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Japan
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Japan; Basic Biology Program, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, Japan
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Ounoki R, Sóti A, Ünnep R, Sipka G, Sárvári É, Garab G, Solymosi K. Etioplasts are more susceptible to salinity stress than chloroplasts and photosynthetically active etio-chloroplasts of wheat (Triticum aestivum L.). PHYSIOLOGIA PLANTARUM 2023; 175:e14100. [PMID: 38148250 DOI: 10.1111/ppl.14100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/05/2023] [Accepted: 11/06/2023] [Indexed: 12/28/2023]
Abstract
High soil salinity is a global problem in agriculture that directly affects seed germination and the development of the seedlings sown deep in the soil. To study how salinity affected plastid ultrastructure, leaf segments of 11-day-old light- and dark-grown (etiolated) wheat (Triticum aestivum L. cv. Mv Béres) seedlings were floated on Hoagland solution, 600 mM KCl:NaCl (1:1) salt or isosmotic polyethylene glycol solution for 4 h in the dark. Light-grown seedlings were also treated in the light. The same treatments were also performed on etio-chloroplasts of etiolated seedlings greened for different time periods. Salt stress induced slight to strong changes in the relative chlorophyll content, photosynthetic activity, and organization of thylakoid complexes. Measurements of malondialdehyde contents and high-temperature thermoluminescence indicated significantly increased oxidative stress and lipid peroxidation under salt treatment, except for light-grown leaves treated in the dark. In chloroplasts of leaf segments treated in the light, slight shrinkage of grana (determined by transmission electron microscopy and small-angle neutron scattering) was observed, while a swelling of the (pro)thylakoid lumen was observed in etioplasts. Salt-induced swelling disappeared after the onset of photosynthesis after 4 h of greening. Osmotic stress caused no significant alterations in plastid structure and only mild changes in their activities, indicating that the swelling of the (pro)thylakoid lumen and the physiological effects of salinity are rather associated with the ionic component of salt stress. Our data indicate that etioplasts of dark-germinated wheat seedlings are the most sensitive to salt stress, especially at the early stages of their greening.
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Affiliation(s)
- Roumaissa Ounoki
- Department of Plant Anatomy, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Adél Sóti
- Department of Plant Anatomy, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Renáta Ünnep
- Neutron Spectroscopy Department, HUN-REN Centre for Energy Research, Budapest, Hungary
| | - Gábor Sipka
- Institute of Plant Biology, HUN-REN Biological Research Center, Szeged, Hungary
| | - Éva Sárvári
- Department of Plant Physiology and Molecular Plant Biology, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Győző Garab
- Institute of Plant Biology, HUN-REN Biological Research Center, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Katalin Solymosi
- Department of Plant Anatomy, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Budapest, Hungary
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Yokono M, Kim E, Minagawa J. The binding of light-harvesting antennae to PsaB suppresses the PSII to PSI spillover. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148995. [PMID: 37433365 DOI: 10.1016/j.bbabio.2023.148995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/15/2023] [Accepted: 07/05/2023] [Indexed: 07/13/2023]
Affiliation(s)
- Makio Yokono
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, Okazaki, Japan.
| | - Eunchul Kim
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, Okazaki, Japan
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, Okazaki, Japan
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Cutolo EA, Caferri R, Guardini Z, Dall'Osto L, Bassi R. Analysis of state 1-state 2 transitions by genome editing and complementation reveals a quenching component independent from the formation of PSI-LHCI-LHCII supercomplex in Arabidopsis thaliana. Biol Direct 2023; 18:49. [PMID: 37612770 PMCID: PMC10463614 DOI: 10.1186/s13062-023-00406-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/07/2023] [Indexed: 08/25/2023] Open
Abstract
BACKGROUND The light-harvesting antennae of photosystem (PS) I and PSII are pigment-protein complexes responsible of the initial steps of sunlight conversion into chemical energy. In natural environments plants are constantly confronted with the variability of the photosynthetically active light spectrum. PSII and PSI operate in series but have different optimal excitation wavelengths. The prompt adjustment of light absorption by photosystems is thus crucial to ensure efficient electron flow needed to sustain downstream carbon fixing reactions. Fast structural rearrangements equilibrate the partition of excitation pressure between PSII and PSI following the enrichment in the red (PSII-favoring) or far-red (PSI-favoring) spectra. Redox imbalances trigger state transitions (ST), a photoacclimation mechanism which involves the reversible phosphorylation/dephosphorylation of light harvesting complex II (LHCII) proteins by the antagonistic activities of the State Transition 7 (STN7) kinase/TAP38 phosphatase enzyme pair. During ST, a mobile PSII antenna pool associates with PSI increasing its absorption cross section. LHCII consists of assorted trimeric assemblies of Lhcb1, Lhcb2 and Lhcb3 protein isoforms (LHCII), several being substrates of STN7. However, the precise roles of Lhcb phosphorylation during ST remain largely elusive. RESULTS We inactivated the complete Lhcb1 and Lhcb2 gene clades in Arabidopsis thaliana and reintroduced either wild type Lhcb1.3 and Lhcb2.1 isoforms, respectively, or versions lacking N-terminal phosphorylatable residues proposed to mediate state transitions. While the substitution of Lhcb2.1 Thr-40 prevented the formation of the PSI-LHCI-LHCII complex, replacement of Lhcb1.3 Thr-38 did not affect the formation of this supercomplex, nor did influence the amplitude or kinetics of PSII fluorescence quenching upon state 1-state 2 transition. CONCLUSIONS Phosphorylation of Lhcb2 Thr-40 by STN7 alone accounts for ≈ 60% of PSII fluorescence quenching during state transitions. Instead, the presence of Thr-38 phosphosite in Lhcb1.3 was not required for the formation of the PSI-LHCI-LHCII supercomplex nor for re-equilibration of the plastoquinone redox state. The Lhcb2 phosphomutant was still capable of ≈ 40% residual fluorescence quenching, implying that a yet uncharacterized, STN7-dependent, component of state transitions, which is unrelated to Lhcb2 Thr-40 phosphorylation and to the formation of the PSI-LHCI-LHCII supercomplex, contributes to the equilibration of the PSI/PSII excitation pressure upon plastoquinone over-reduction.
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Affiliation(s)
- Edoardo Andrea Cutolo
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Roberto Caferri
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Zeno Guardini
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Luca Dall'Osto
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Roberto Bassi
- Laboratory of Photosynthesis and Bioenergy, Department of Biotechnology, University of Verona, Strada le Grazie 15, 37134, Verona, Italy.
- Accademia Nazionale dei Lincei, Palazzo Corsini, Via Della Lungara, 10, 00165, Rome, Italy.
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Kim E, Yokono M, Tsugane K, Ishii A, Noda C, Minagawa J. Formation of a Stable PSI-PSII Megacomplex in Rice That Conducts Energy Spillover. PLANT & CELL PHYSIOLOGY 2023; 64:858-865. [PMID: 37130092 DOI: 10.1093/pcp/pcad037] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 04/27/2023] [Accepted: 04/27/2023] [Indexed: 05/03/2023]
Abstract
In green plants, photosystem I (PSI) and photosystem II (PSII) bind to their respective light-harvesting complexes (LHCI and LHCII) to form the PSI-LHCI supercomplex and the PSII-LHCII supercomplex, respectively. These supercomplexes further form megacomplexes, like PSI-PSII and PSII-PSII in Arabidopsis (Arabidopsis thaliana) and spinach to modulate their light-harvesting properties, but not in the green alga Chlamydomonas reinhardtii. Here, we fractionated and characterized the stable rice PSI-PSII megacomplex. The delayed fluorescence from PSI (lifetime ∼25 ns) indicated energy transfer capabilities between the two photosystems (energy spillover) in the rice PSI-PSII megacomplex. Fluorescence lifetime analysis revealed that the slow PSII to PSI energy transfer component was more dominant in the rice PSI-PSII supercomplexes than in Arabidopsis ones, suggesting that PSI and PSII in rice form a megacomplex not directly but through LHCII molecule(s), which was further confirmed by the negatively stained electron microscopy analysis. Our results suggest species diversity in the formation and stability of photosystem megacomplexes, and the stable PSI-PSII supercomplex in rice may reflect its structural adaptation.
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Affiliation(s)
- Eunchul Kim
- Division of Environmental Photobiology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
- Department of Basic Biology in the School of Life Science, The Graduate University for Advanced Studies, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
| | - Makio Yokono
- Division of Environmental Photobiology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
- Department of Basic Biology in the School of Life Science, The Graduate University for Advanced Studies, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
| | - Kazuo Tsugane
- Department of Evolutionary Biology and Biodiversity, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
| | - Asako Ishii
- Division of Environmental Photobiology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
| | - Chiyo Noda
- Division of Environmental Photobiology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
- Department of Basic Biology in the School of Life Science, The Graduate University for Advanced Studies, 38 Nishigonaka, Myodaiji Okazaki, Aichi, 444-8585 Japan
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Ifuku K. Diversity of the PSI-PSII Megacomplexes That Conduct Energy Spillover in Green Plants. PLANT & CELL PHYSIOLOGY 2023; 64:844-846. [PMID: 37384582 DOI: 10.1093/pcp/pcad069] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/01/2023]
Affiliation(s)
- Kentaro Ifuku
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502 Japan
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8
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Sapeta H, Yokono M, Takabayashi A, Ueno Y, Cordeiro AM, Hara T, Tanaka A, Akimoto S, Oliveira MM, Tanaka R. Reversible down-regulation of photosystems I and II leads to fast photosynthesis recovery after long-term drought in Jatropha curcas. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:336-351. [PMID: 36269314 DOI: 10.1093/jxb/erac423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Jatropha curcas is a drought-tolerant plant that maintains its photosynthetic pigments under prolonged drought, and quickly regains its photosynthetic capacity when water is available. It has been reported that drought stress leads to increased thermal dissipation in PSII, but that of PSI has been barely investigated, perhaps due to technical limitations in measuring the PSI absolute quantum yield. In this study, we combined biochemical analysis and spectroscopic measurements using an integrating sphere, and verified that the quantum yields of both photosystems are temporarily down-regulated under drought. We found that the decrease in the quantum yield of PSII was accompanied by a decrease in the core complexes of PSII while light-harvesting complexes are maintained under drought. In addition, in drought-treated plants, we observed a decrease in the absolute quantum yield of PSI as compared with the well-watered control, while the amount of PSI did not change, indicating that non-photochemical quenching occurs in PSI. The down-regulation of both photosystems was quickly lifted in a few days upon re-watering. Our results indicate, that in J. curcas under drought, the down-regulation of both PSII and PSI quantum yield protects the photosynthetic machinery from uncontrolled photodamage.
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Affiliation(s)
- Helena Sapeta
- Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica António Xavier, Genomics of Plant Stress, Av. da República, 2780-157 Oeiras, Portugal
| | - Makio Yokono
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
- Department of Basic Biology, School of Life Science, the Graduate University for Advanced Studies, Sokendai, Okazaki 444-8585, Japan
| | - Atsushi Takabayashi
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, Kobe 657-8501, Japan
| | - André M Cordeiro
- Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica António Xavier, Genomics of Plant Stress, Av. da República, 2780-157 Oeiras, Portugal
| | - Toshihiko Hara
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Kobe 657-8501, Japan
| | - M Margarida Oliveira
- Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica António Xavier, Genomics of Plant Stress, Av. da República, 2780-157 Oeiras, Portugal
| | - Ryouichi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
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Manoj KM, Gideon DA, Parashar A, Nirusimhan V, Annadurai P, Jacob VD, Manekkathodi A. Validating the predictions of murburn model for oxygenic photosynthesis: Analyses of ligand-binding to protein complexes and cross-system comparisons. J Biomol Struct Dyn 2022; 40:11024-11056. [PMID: 34328391 DOI: 10.1080/07391102.2021.1953607] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this second half of our treatise on oxygenic photosynthesis, we provide support for the murburn model of the light reaction of photosynthesis and ratify key predictions made in the first part. Molecular docking and visualization of various ligands of quinones/quinols (and their derivatives) with PS II/Cytochrome b6f complexes did not support chartered 2e-transport role of quinols. A broad variety of herbicides did not show any affinity/binding-based rationales for inhibition of photosynthesis. We substantiate the proposal that disubstituted phenolics (perceived as protonophores/uncouplers or affinity-based inhibitors in the classical purview) serve as interfacial modulators of diffusible reactive (oxygen) species or DR(O)S. The DRS-based murburn model is evidenced by the identification of multiple ADP-binding sites on the extra-membraneous projection of protein complexes and structure/distribution of the photo/redox catalysts. With a panoramic comparison of the redox metabolic machinery across diverse organellar/cellular systems, we highlight the ubiquitous one-electron murburn facets (cofactors of porphyrin, flavin, FeS, other metal centers and photo/redox active pigments) that enable a facile harnessing of the utility of DRS. In the summative analyses, it is demonstrated that the murburn model of light reaction explains the structures of membrane supercomplexes recently observed in thylakoids and also accounts for several photodynamic experimental observations and evolutionary considerations. In toto, the work provides a new orientation and impetus to photosynthesis research. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kelath Murali Manoj
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Daniel Andrew Gideon
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Abhinav Parashar
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Vijay Nirusimhan
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Pushparaj Annadurai
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Vivian David Jacob
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Afsal Manekkathodi
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
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Mohamed A, Nishi S, Kawakami K, Shen JR, Itoh S, Fukumura H, Shibata Y. Exciton quenching by oxidized chlorophyll Z across the two adjacent monomers in a photosystem II core dimer. PHOTOSYNTHESIS RESEARCH 2022; 154:277-289. [PMID: 35976595 DOI: 10.1007/s11120-022-00948-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
This study aimed to clarify (1) which pigment in a photosystem II (PSII) core complex is responsible for the 695-nm emission at 77 K and (2) the molecular basis for the oxidation-induced fluorescence quenching in PSII. Picosecond time-resolved fluorescence dynamics was compared between the dimeric and monomeric PSII with and without addition of an oxidant. The results indicated that the excitation-energy flow to the 695-nm-emitting chlorophyll (Chl) at 36 K and 77 K was hindered upon monomerization, clearly demonstrating significant exciton migration from the Chls on one monomer to the 695-nm-emitting pigment on the adjacent monomer. Oxidation of the redox-active Chl, which is named ChlZ caused almost equal quenching of the 684-nm and 695-nm emission bands in the dimer, and lower quenching of the 695-nm band in the monomer. These results suggested two possible scenarios responsible for the 695-nm emission band: (A) Chl11-13 pair and the oxidized ChlZD1 work as the 695-nm emitting Chl and the quenching site, respectively, and (B) Chl29 and the oxidized ChlZD2 work as the 695-nm emitting Chl and the quenching site, respectively.
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Affiliation(s)
- Ahmed Mohamed
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, 1650, Boul. Lionel-Boulet, Varennes, QC, J3X 1S2, Canada
| | - Shunsuke Nishi
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Keisuke Kawakami
- Biostructural Mechanism Laboratory, RIKEN Spring-8 Center, Hyogo, 679-5148, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Shigeru Itoh
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Hiroshi Fukumura
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001, Leuven, Belgium
| | - Yutaka Shibata
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan.
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11
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Teng Z, Zheng W, Jiang S, Hong SB, Zhu Z, Zang Y. Role of melatonin in promoting plant growth by regulating carbon assimilation and ATP accumulation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 319:111276. [PMID: 35487649 DOI: 10.1016/j.plantsci.2022.111276] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/23/2022] [Accepted: 03/27/2022] [Indexed: 05/27/2023]
Abstract
Melatonin (MT) is a phytohormone important in mediating diverse plant growth processes. In this study, we performed transcriptomic, qRT-PCR, physiological and biochemical analyses of Brassica rapa seedlings in order to understand how MT promotes plant growth. The results showed that exogenous MT increased the rate of cyclic electron flow around photosystem (PS) I, fluorescence quantum yield, and electron transport efficiency between PSII and PSI to promote the vegetative growth of B. rapa seedlings without affecting oxidative stress level, as compared to control. However, MT treatment significantly reduced photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) by 2.25-, 1.23- and 3.50-fold at 0.05 level, respectively. This occurred in parallel with the down-regulation of the genes for carbon fixation in photosynthetic organisms in a KEGG pathway enrichment. More accelerated plant growth despite the reduced photosynthesis rate and the enhanced electron transport rate suggested that NADPH and adenosine triphosphate (ATP) were preferentially diverted into other anabolic reactions than the Calvin cycle upon MT application. MT treatment increased ATP level and facilitated carbon assimilation into primary metabolism that led to a significant enhancement of soluble protein, sucrose, and fructose, but a significant decrease in glucose content. MT-induced carbon assimilation into primary metabolism was driven by up-regulation of the genes for glutathione metabolism, Krebs cycle, ribosome, and DNA replication in a KEGG pathway enrichment, as well as down-regulation of the genes for secondary metabolites. Our results provide an insight into MT-mediated metabolic adjustments triggered by coordinate changes in a wide range of gene expression profiles to help improve the plant functionality.
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Affiliation(s)
- Zhiyan Teng
- Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas, College of Horticulture Science, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China; Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, College of Horticulture Science, Zhejiang A&~F University, Hangzhou, Zhejiang 311300, China
| | - Weiwei Zheng
- Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas, College of Horticulture Science, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China; Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, College of Horticulture Science, Zhejiang A&~F University, Hangzhou, Zhejiang 311300, China
| | - Shufang Jiang
- Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas, College of Horticulture Science, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China; Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, College of Horticulture Science, Zhejiang A&~F University, Hangzhou, Zhejiang 311300, China
| | - Seung-Beom Hong
- Department of Biotechnology, University of Houston Clear Lake, Houston, TX 77058-1098, USA
| | - Zhujun Zhu
- Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas, College of Horticulture Science, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China; Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, College of Horticulture Science, Zhejiang A&~F University, Hangzhou, Zhejiang 311300, China
| | - Yunxiang Zang
- Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas, College of Horticulture Science, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China; Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, College of Horticulture Science, Zhejiang A&~F University, Hangzhou, Zhejiang 311300, China.
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12
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Sárvári É, Gellén G, Sági-Kazár M, Schlosser G, Solymosi K, Solti Á. Qualitative and quantitative evaluation of thylakoid complexes separated by Blue Native PAGE. PLANT METHODS 2022; 18:23. [PMID: 35241118 PMCID: PMC8895881 DOI: 10.1186/s13007-022-00858-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 02/12/2022] [Indexed: 05/26/2023]
Abstract
BACKGROUND Blue Native polyacrylamide gel electrophoresis (BN PAGE) followed by denaturing PAGE is a widely used, convenient and time efficient method to separate thylakoid complexes and study their composition, abundance, and interactions. Previous analyses unravelled multiple monomeric and dimeric/oligomeric thylakoid complexes but, in certain cases, the separation of complexes was not proper. Particularly, the resolution of super- and megacomplexes, which provides important information on functional interactions, still remained challenging. RESULTS Using a detergent mixture of 1% (w/V) n-dodecyl-β-D-maltoside plus 1% (w/V) digitonin for solubilisation and 4.3-8% gel gradients for separation as methodological improvements in BN PAGE, several large photosystem (PS) I containing bands were detected. According to BN(/BN)/SDS PAGE and mass spectrometry analyses, these PSI bands proved to be PSI-NADH dehydrogenase-like megacomplexes more discernible in maize bundle sheath thylakoids, and PSI complexes with different light-harvesting complex (LHC) complements (PSI-LHCII, PSI-LHCII*) more abundant in mesophyll thylakoids of lincomycin treated maize. For quantitative determination of the complexes and their comparison across taxa and physiological conditions, sample volumes applicable to the gel, correct baseline determination of the densitograms, evaluation methods to resolve complexes running together, calculation of their absolute/relative amounts and distribution among their different forms are proposed. CONCLUSIONS Here we report our experience in Blue/Clear-Native polyacrylamide gel electrophoretic separation of thylakoid complexes, their identification, quantitative determination and comparison in different samples. The applied conditions represent a powerful methodology for the analysis of thylakoid mega- and supercomplexes.
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Affiliation(s)
- Éva Sárvári
- Department of Plant Physiology and Molecular Plant Biology, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary.
| | - Gabriella Gellén
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest, 1117, Hungary
| | - Máté Sági-Kazár
- Department of Plant Physiology and Molecular Plant Biology, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
- Doctoral School of Biology, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
| | - Gitta Schlosser
- MTA-ELTE Lendület Ion Mobility Mass Spectrometry Research Group, Institute of Chemistry, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest, 1117, Hungary
| | - Katalin Solymosi
- Department of Plant Anatomy, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
| | - Ádám Solti
- Department of Plant Physiology and Molecular Plant Biology, Institute of Biology, Faculty of Science, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/C, Budapest, 1117, Hungary
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Colpo A, Baldisserotto C, Pancaldi S, Sabia A, Ferroni L. Photosystem II photoinhibition and photoprotection in a lycophyte, Selaginella martensii. PHYSIOLOGIA PLANTARUM 2022; 174:e13604. [PMID: 34811759 PMCID: PMC9300044 DOI: 10.1111/ppl.13604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/09/2021] [Accepted: 11/19/2021] [Indexed: 05/13/2023]
Abstract
The Lycophyte Selaginella martensii efficiently acclimates to diverse light environments, from deep shade to full sunlight. The plant does not modulate the abundance of the Light Harvesting Complex II, mostly found as a free trimer, and does not alter the maximum capacity of thermal dissipation (NPQ). Nevertheless, the photoprotection is expected to be modulatable upon long-term light acclimation to preserve the photosystems (PSII, PSI). The effects of long-term light acclimation on PSII photoprotection were investigated using the chlorophyll fluorometric method known as "photochemical quenching measured in the dark" (qPd ). Singularly high-qPd values at relatively low irradiance suggest a heterogeneous antenna system (PSII antenna uncoupling). The extent of antenna uncoupling largely depends on the light regime, reaching the highest value in sun-acclimated plants. In parallel, the photoprotective NPQ (pNPQ) increased from deep-shade to high-light grown plants. It is proposed that the differences in the long-term modulation in the photoprotective capacity are proportional to the amount of uncoupled LHCII. In deep-shade plants, the inconsistency between invariable maximum NPQ and lower pNPQ is attributed to the thermal dissipation occurring in the PSII core.
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Affiliation(s)
- Andrea Colpo
- Department of Environmental and Prevention SciencesUniversity of FerraraFerrara
| | | | - Simonetta Pancaldi
- Department of Environmental and Prevention SciencesUniversity of FerraraFerrara
| | - Alessandra Sabia
- Department of Environmental and Prevention SciencesUniversity of FerraraFerrara
| | - Lorenzo Ferroni
- Department of Environmental and Prevention SciencesUniversity of FerraraFerrara
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Rogowski P, Urban A, Romanowska E. Light as a substrate: migration of LHCII antennas in extended Michaelis-Menten model for PSI kinetics. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2021; 225:112336. [PMID: 34736069 DOI: 10.1016/j.jphotobiol.2021.112336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/12/2021] [Accepted: 10/15/2021] [Indexed: 11/19/2022]
Abstract
We extended, for the first time, the Michaelis-Menten (M-M) model to describe the kinetics of photosystem I (PSI) complexes using light as a substrate. Our work is novel as it can be useful for studying the phenomenon of "state transitions" because it quantifies the affinity of light to PSI reaction centers depending on the associated light harvesting complex II (LHCII) antennas. We verified our models by measuring the PSI activity as a function of light intensity using an oxygen electrode for chloroplast from plants grown in low light conditions and treated with far red light. We determined the kinetics constant KM for: PSI-LHCI, PSI-LHCI-LHCII and PSI-PSII megacomplexes and have shown that KM for PSI located in the megacomplexes was smaller in magnitude than PSI-LHCI, thus demonstrating that LHCII antennas are functionally associated with PSI. The parameter [S]1/2used in our models is the equivalent of M-M constant. Far red light increases [S]1/2, which indicates that transition from state 1 to state 2 leads to an energy gain while reaching the PSI reaction centers. We also observed that redistribution of the absorbed excitation energy is realized not only by LHCII migration but also by association of the photosystems in the megacomplexes.
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Affiliation(s)
- Paweł Rogowski
- Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02096 Warsaw, Poland.
| | - Aleksandra Urban
- Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02096 Warsaw, Poland.
| | - Elżbieta Romanowska
- Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02096 Warsaw, Poland.
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15
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Nagao R, Yokono M, Kato KH, Ueno Y, Shen JR, Akimoto S. High-light modification of excitation-energy-relaxation processes in the green flagellate Euglena gracilis. PHOTOSYNTHESIS RESEARCH 2021; 149:303-311. [PMID: 34037905 DOI: 10.1007/s11120-021-00849-9] [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: 01/05/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
Photosynthetic organisms finely tune their photosynthetic machinery including pigment compositions and antenna systems to adapt to various light environments. However, it is poorly understood how the photosynthetic machinery in the green flagellate Euglena gracilis is modified under high-light conditions. In this study, we examined high-light modification of excitation-energy-relaxation processes in Euglena cells. Oxygen-evolving activity in the cells incubated at 300 µmol photons m-2 s-1 (HL cells) cannot be detected, reflecting severe photodamage to photosystem II (PSII) in vivo. Pigment compositions in the HL cells showed relative increases in 9'-cis-neoxanthin, diadinoxanthin, and chlorophyll b compared with the cells incubated at 30 µmol photons m-2 s-1 (LL cells). Absolute fluorescence spectra at 77 K exhibit smaller intensities of the PSII and photosystem I (PSI) fluorescence in the HL cells than in the LL cells. Absolute fluorescence decay-associated spectra at 77 K of the HL cells indicate suppression of excitation-energy transfer from light-harvesting complexes (LHCs) to both PSI and PSII with the time constant of 40 ps. Rapid energy quenching in LHCs and PSII in the HL cells is distinctly observed by averaged Chl-fluorescence lifetimes. These findings suggest that Euglena modifies excitation-energy-relaxation processes in addition to pigment compositions to deal with excess energy. These results provide insights into the photoprotection strategies of this alga under high-light conditions.
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Affiliation(s)
- Ryo Nagao
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
| | - Makio Yokono
- Institute of Low Temperature Science, Hokkaido University, Hokkaido, 060-0819, Japan
| | - Ka-Ho Kato
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, Hyogo, 657-8501, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Hyogo, 657-8501, Japan.
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16
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Terashima I, Matsuo M, Suzuki Y, Yamori W, Kono M. Photosystem I in low light-grown leaves of Alocasia odora, a shade-tolerant plant, is resistant to fluctuating light-induced photoinhibition. PHOTOSYNTHESIS RESEARCH 2021; 149:69-82. [PMID: 33817762 DOI: 10.1007/s11120-021-00832-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/22/2021] [Indexed: 05/15/2023]
Abstract
When intact green leaves are exposed to the fluctuating light, in which high light (HL) and low light (LL) alternate, photosystem I (PSI) is readily damaged. This PSI inhibition is mostly alleviated by the addition of far-red (FR) light. Here, we grew Alocasia odora, a shade-tolerant species, at several light levels and examined their photosynthetic traits in relation to the fluctuating light-induced PSI inhibition. We found that, even in the absence of FR, PSI in LL-grown leaves was resistant to the fluctuating light. LL leaves showed higher chlorophyll (Chl) contents on leaf area basis, lower Chl a/b ratios, lower cytochrome f/P700 ratios, and lower PSII/PSI excitation ratios assessed by the 77 K fluorescence. Also, P700 in the HL phase of the fluctuating light was more oxidized. The results of the regression analyses of the PSI photoinhibition to these traits indicate that the lower electron flow rate to P700 and more excitation energy transfer to PSI protect PSI in LL-grown leaves. Both of these contribute oxidization of P700 to the efficient quencher form P700+. These features may be common in LL-grown shade-tolerant species, which are often exposed to strong sunflecks in their natural habitats.
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Affiliation(s)
- Ichiro Terashima
- Department of Biological Sciences, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Mitsutoshi Matsuo
- Department of Biological Sciences, 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
| | - Wataru Yamori
- Department of Biological Sciences, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
- Institute for Sustainable Agro-ecosystem Services (ISAS), Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Midori-cho, Nishitokyo-City, Tokyo, 188-0002, Japan
| | - Masaru Kono
- Department of Biological Sciences, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
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Aso M, Matsumae R, Tanaka A, Tanaka R, Takabayashi A. Unique Peripheral Antennas in the Photosystems of the Streptophyte Alga Mesostigma viride. PLANT & CELL PHYSIOLOGY 2021; 62:436-446. [PMID: 33416834 DOI: 10.1093/pcp/pcaa172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/19/2020] [Indexed: 06/12/2023]
Abstract
Land plants evolved from a single group of streptophyte algae. One of the key factors needed for adaptation to a land environment is the modification in the peripheral antenna systems of photosystems (PSs). Here, the PSs of Mesostigma viride, one of the earliest-branching streptophyte algae, were analyzed to gain insight into their evolution. Isoform sequencing and phylogenetic analyses of light-harvesting complexes (LHCs) revealed that M. viride possesses three algae-specific LHCs, including algae-type LHCA2, LHCA9 and LHCP, while the streptophyte-specific LHCB6 was not identified. These data suggest that the acquisition of LHCB6 and the loss of algae-type LHCs occurred after the M. viride lineage branched off from other streptophytes. Clear-native (CN)-polyacrylamide gel electrophoresis (PAGE) resolved the photosynthetic complexes, including the PSI-PSII megacomplex, PSII-LHCII, two PSI-LHCI-LHCIIs, PSI-LHCI and the LHCII trimer. Results indicated that the higher-molecular weight PSI-LHCI-LHCII likely had more LHCII than the lower-molecular weight one, a unique feature of M. viride PSs. CN-PAGE coupled with mass spectrometry strongly suggested that the LHCP was bound to PSII-LHCII, while the algae-type LHCA2 and LHCA9 were bound to PSI-LHCI, both of which are different from those in land plants. Results of the present study strongly suggest that M. viride PSs possess unique features that were inherited from a common ancestor of streptophyte and chlorophyte algae.
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Affiliation(s)
- Michiki Aso
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819 Japan
| | - Renon Matsumae
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819 Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819 Japan
| | - Ryouichi Tanaka
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819 Japan
| | - Atsushi Takabayashi
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819 Japan
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Ling N, Li W, Xu G, Qi Z, Ji C, Liu X, Cui D, Sun Y. Transcriptomic sequencing reveals the response of Dunaliella salina to copper stress via the increased photosynthesis and carbon mechanism. Mol Omics 2021; 17:769-782. [PMID: 34254634 DOI: 10.1039/d1mo00125f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Copper (Cu) is one of the essential microelements for plants and algae. It can stimulate growth and photosynthesis at low concentration but inhibit them at higher concentration. The knowledge of molecular response mechanisms to copper stress in green algae is still limited. The responses of the green algae Dunaliella salina to Cu stress were studied using the physiochemical indexes and RNA-seq analysis. The physiochemical indexes such as growth rate, the content of chlorophyll and soluble sugar, photosynthesis and peroxidase activity were all changed in D. salina under Cu stress. In addition, a total of 3799 differentially expressed genes (DEGs) were identified between the control and Cu-treated group. Among these, 2350 unigenes were up-regulated whereas 1449 were down-regulated. Here, the DEGs encoding proteins relevant to photosynthesis, carbon assimilation and carbohydrate mechanism were significantly up-regulated in the Cu-treated group. In addition, the unigenes encoding proteins involved in the antioxidant system and heat shock proteins were also up-regulated, and these were consistent with the expression patterns based on TPM (transcripts per million) values. This study shows that the enhanced growth and photosynthesis and carbon mechanism in D. salina can be triggered by copper, which will lay a firm foundation for future breeding and carotenoid production, further highlighting the underlying application of D. salina as a functional food.
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Affiliation(s)
- Na Ling
- Engineering Research Center for Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, Heilongjiang 150076, China. and Engineering Research Center for Medicines, Harbin University of Commerce, Harbin, Heilongjiang 150076, China.
| | - Weilu Li
- Engineering Research Center for Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, Heilongjiang 150076, China.
| | - Guiguo Xu
- Engineering Research Center for Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, Heilongjiang 150076, China.
| | - Zheng Qi
- Engineering Research Center for Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, Heilongjiang 150076, China. and Engineering Research Center for Medicines, Harbin University of Commerce, Harbin, Heilongjiang 150076, China.
| | - Chenfeng Ji
- Engineering Research Center for Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, Heilongjiang 150076, China. and Engineering Research Center for Medicines, Harbin University of Commerce, Harbin, Heilongjiang 150076, China.
| | - Xiaorui Liu
- Engineering Research Center for Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, Heilongjiang 150076, China.
| | - Di Cui
- Engineering Research Center for Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, Heilongjiang 150076, China.
| | - Yuan Sun
- Engineering Research Center for Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, Heilongjiang 150076, China. and Engineering Research Center for Medicines, Harbin University of Commerce, Harbin, Heilongjiang 150076, China.
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Giovagnetti V, Ruban AV. The mechanism of regulation of photosystem I cross-section in the pennate diatom Phaeodactylum tricornutum. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:561-575. [PMID: 33068431 DOI: 10.1093/jxb/eraa478] [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: 07/08/2020] [Accepted: 10/12/2020] [Indexed: 06/11/2023]
Abstract
Photosystems possess distinct fluorescence emissions at low (77K) temperature. PSI emits in the long-wavelength region at ~710-740 nm. In diatoms, a successful clade of marine primary producers, the contribution of PSI-associated emission (710-717 nm) has been shown to be relatively small. However, in the pennate diatom Phaeodactylum tricornutum, the source of the long-wavelength emission at ~710 nm (F710) remains controversial. Here, we addressed the origin and modulation of F710 fluorescence in this alga grown under continuous and intermittent light. The latter condition led to a strong enhancement in F710. Biochemical and spectral properties of the photosynthetic complexes isolated from thylakoid membranes were investigated for both culture conditions. F710 emission appeared to be associated with PSI regardless of light acclimation. To further assess whether PSII could also contribute to this emission, we decreased the concentration of PSII reaction centres and core antenna by growing cells with lincomycin, a chloroplast protein synthesis inhibitor. The treatment did not diminish F710 fluorescence. Our data suggest that F710 emission originates from PSI under the conditions tested and is enhanced in intermittent light-grown cells due to increased energy flow from the FCP antenna to PSI.
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Affiliation(s)
- Vasco Giovagnetti
- Department of Biochemistry, School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Alexander V Ruban
- Department of Biochemistry, School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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20
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Ferroni L, Colpo A, Baldisserotto C, Pancaldi S. In an ancient vascular plant the intermediate relaxing component of NPQ depends on a reduced stroma: Evidence from dithiothreitol treatment. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2021; 215:112114. [PMID: 33385824 DOI: 10.1016/j.jphotobiol.2020.112114] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/17/2020] [Accepted: 12/19/2020] [Indexed: 10/22/2022]
Abstract
In plants, the non-photochemical quenching of chlorophyll fluorescence (NPQ) induced by high light reveals the occurrence of a multiplicity of regulatory processes of photosynthesis, primarily devoted to photoprotection of photosystem I and II (PSI and PSII). The study of NPQ relaxation in darkness allows the separation of three kinetically distinct phases: the fast relaxing high-energy quenching qE, the intermediate relaxing phase and the nearly non-relaxatable photoinhibitory quenching. Several processes can underlie the intermediate phase. In the ancient vascular plant Selaginella martensii (Lycopodiophyta) this component, here termed qX, was previously proposed to reflect mainly a photoprotective energy-spillover from PSII to PSI. It is hypothesized that qX is induced by an over-reduced photosynthetic electron transport chain from PSII to final acceptors. To test this hypothesis the leaves were treated with the reductant dithiothreitol (DTT) and the chlorophyll fluorescence changes were analysed during the induction with high irradiance and the subsequent relaxation in darkness. DTT treatment caused the well-known decrease in NPQ induction and expectedly resulted in a disturbed photosynthetic electron flow. The relaxation curves of Y(NPQ), formally representing the quantum yield of the regulatory thermal dissipation, revealed a DTT dose-dependent decrease in amplitude not only of qE, but also of qX, up to the complete disappearance of the latter. Modelling of the relaxation curves under alternative scenarios led to the conclusion that DTT is permissive with respect to qX induction but suppresses its dark relaxation. The strong dependence of qX on the chloroplast redox state is discussed with respect to its proposed energy-spillover photoprotective significance in a lycophyte.
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Affiliation(s)
- Lorenzo Ferroni
- Laboratory of Plant Cytophysiology, Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
| | - Andrea Colpo
- Laboratory of Plant Cytophysiology, Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Costanza Baldisserotto
- Laboratory of Plant Cytophysiology, Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Simonetta Pancaldi
- Laboratory of Plant Cytophysiology, Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
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21
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Tanabe M, Ueno Y, Yokono M, Shen JR, Nagao R, Akimoto S. Changes in excitation relaxation of diatoms in response to fluctuating light, probed by fluorescence spectroscopies. PHOTOSYNTHESIS RESEARCH 2020; 146:143-150. [PMID: 32067138 DOI: 10.1007/s11120-020-00720-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/10/2020] [Indexed: 06/10/2023]
Abstract
A marine pennate diatom Phaeodactylum tricornutum (Pt) and a marine centric diatom Chaetoceros gracilis (Cg) possess unique light-harvesting complexes, fucoxanthin chlorophyll a/c-binding proteins (FCPs). FCPs have dual functions: light harvesting in the blue to green regions and quenching of excess energy. So far, excitation dynamics including FCPs have been studied by altering continuous light conditions. In the present study, we examined responses of the diatom cells to fluctuating light (FL) conditions. Excitation dynamics in the cells incubated under the FL conditions were analyzed by time-resolved fluorescence measurements followed by global analysis. As responses common to the Pt and Cg cells, quenching behaviors were observed in photosystem (PS) II with time constants of hundreds of picoseconds. The PSII → PSI energy transfer was modified only in the Pt cells, whereas quenching in FCPs was suggested only in the Cg cells, indicating different strategy for the dissipation of excess energy under the FL conditions.
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Affiliation(s)
- Miyuki Tanabe
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Makio Yokono
- Innovation Center, Nippon Flour Mills Co., Ltd., Atsugi, 243-0041, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Ryo Nagao
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan.
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22
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Urban A, Rogowski P, Wasilewska-Dębowska W, Romanowska E. Effect of light on the rearrangements of PSI super-and megacomplexes in the non-appressed thylakoid domains of maize mesophyll chloroplasts. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 301:110655. [PMID: 33218624 DOI: 10.1016/j.plantsci.2020.110655] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
We demonstrated the existence of PSI-LHCI-LHCII-Lhcb4 supercomplexes and PSI-LHCI-PSII-LHCII megacomplexes in the stroma lamellae and grana margins of maize mesophyll chloroplasts; these complexes consist of different LHCII trimers and monomer antenna proteins per PSI photocentre. These complexes are formed in both low (LL) and high (HL) light growth conditions, but with different contents. We attempted to identify the components and structure of these complexes in maize chloroplasts isolated from the leaves of low and high light-grown plants after darkness and transition to far red (FR) light of high intensity. Exposition of plants from high and low light growth condition on FR light induces different rearrangements in the composition of super- and megacomplexes. During FR light exposure, in plants from LL, the PSI-LHCI-LHCII-Lhcb4 supercomplex dissociates into free LHCII-Lhcb4 and PSI-LHCI complexes, and these complexes associate with the PSII monomer. This process occurs differently in plants from HL. Exposition to FR light causes dissociation of both PSI-LHCI-LHCII-Lhcb4 supercomplexes and PSI-PSII megacomplexes. These results suggest a different function of super- and megacomplex organization than the classic state transitions model, which assumes that the movement of LHCII trimers in the thylakoid membraneis considered as a mechanism for balancing light absorption between the two photosystems in light stress. The behavior of the complexes described in this article does not seem to be well explained by this model, i.e., it does not seem likely that the primary purpose of these megacomplexes dynamics is to balance excitation pressure. Rather, as stated in this article, it seems to indicate a role of these complexes for PSI in excitation quenching and for PSII in turnover.
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Affiliation(s)
- Aleksandra Urban
- Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02096 Warsaw, Poland
| | - Paweł Rogowski
- Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02096 Warsaw, Poland
| | - Wioleta Wasilewska-Dębowska
- Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02096 Warsaw, Poland
| | - Elżbieta Romanowska
- Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02096 Warsaw, Poland.
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23
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Oka K, Ueno Y, Yokono M, Shen JR, Nagao R, Akimoto S. Adaptation of light-harvesting and energy-transfer processes of a diatom Phaeodactylum tricornutum to different light qualities. PHOTOSYNTHESIS RESEARCH 2020; 146:227-234. [PMID: 31965467 DOI: 10.1007/s11120-020-00714-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 01/13/2020] [Indexed: 06/10/2023]
Abstract
Fucoxanthin-chlorophyll (Chl) a/c-binding proteins (FCPs) are light-harvesting pigment-protein complexes found in diatoms and brown algae. Due to the characteristic pigments, such as fucoxanthin and Chl c, FCPs can capture light energy in blue-to green regions. A pennate diatom Phaeodactylum tricornutum synthesizes a red-shifted form of FCP under weak or red light, extending a light-absorption ability to longer wavelengths. In the present study, we examined changes in light-harvesting and energy-transfer processes of P. tricornutum cells grown under white- and single-colored light-emitting diodes (LEDs). The red-shifted FCP appears in the cells grown under the green, yellow, and red LEDs, and exhibited a fluorescence peak around 714 nm. Additional energy-transfer pathways are established in the red-shifted FCP; two forms (F713 and F718) of low-energy Chl a work as energy traps at 77 K. Averaged fluorescence lifetimes are prolonged in the cells grown under the yellow and red LEDs, whereas they are shortened in the blue-LED-grown cells. Based on these results, we discussed the light-adaptation machinery of P. tricornutum cells involved in the red-shifted FCP.
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Affiliation(s)
- Kumiko Oka
- Faculty of Science, Kobe University, Kobe, 657-8501, Japan
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Makio Yokono
- Innovation Center, Nippon Flour Mills Co., Ltd, Atsugi, 243-0041, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Ryo Nagao
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
| | - Seiji Akimoto
- Faculty of Science, Kobe University, Kobe, 657-8501, Japan.
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan.
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24
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Wu L, Zhang L, Tu W, Sun R, Li F, Lin Y, Zhang Y, Liu C, Yang C. Photosynthetic inner antenna CP47 plays important roles in ephemeral plants in adapting to high light stress. JOURNAL OF PLANT PHYSIOLOGY 2020; 251:153189. [PMID: 32526555 DOI: 10.1016/j.jplph.2020.153189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/08/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
Throughout 3.5 billion years of evolution, photosynthesis of land plants has developed a complicated antenna system to cope with the ever-changing environments. The antenna system of photosystem (PS) II includes the outer antennae and inner antennae. The inner antennae CP43 and CP47, located in the closest peripheral of PSII reaction center (RC), play important roles in facilitating excitation energy transport from the outer antennae to the PSII RC. Although PSII RC is the last station of energy transport, it is the inner antenna CP47, not the RC, which possesses the lowest energy level in PSII. Berteroa incana (B. incana), which is a vascular plant grown in the Gobi region, can sustain very high photosynthesis capacity under very high light conditions. It has been discovered that the thylakoid membrane of B. incana possesses a unique low fluorescence emission spectrum because the fluorescence emission of CP47 (695 nm) is the main fluorescence emission peak of PSII. In this paper, the thylakoid membrane, isolated from B. incana grown under a light condition of 100 μM photons m-2 s-1 and subjected to high light treatment (1600 μM photons m-2 s-1 for 1.5 h or 3 h) was employed for the research. It has been found that the high fluorescence emission of CP47 decreased remarkably upon exposure to the high light treatment. Further observation revealed that the drastic changes in the CP47 fluorescence emission were accompanied by a slight reduction in the amount of CP47 and an enhancement of the CP29-LHCII-CP24 assembly. It is proposed that CP47 enables the functional switch between the excitation energy transfer towards PSII RC, and the overexcitation quenching in the PSII core. Together with CP43, CP47 plays important roles in regulating excitation energy distribution in PSII core complexes.
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Affiliation(s)
- Lishuan Wu
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lin Zhang
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenfeng Tu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Ruixue Sun
- Qingdao Institute, Shanghai Institute of Technological Physics, Chinese Academy of Sciences, Qingdao 264000, China
| | - Fei Li
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yajun Lin
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute and Geography, Chinese Academy of Sciences, Urumqi 830011, China
| | - Yuanming Zhang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute and Geography, Chinese Academy of Sciences, Urumqi 830011, China
| | - Cheng Liu
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Chunhong Yang
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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25
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Nagao R, Yokono M, Ueno Y, Shen JR, Akimoto S. Excitation-Energy Transfer and Quenching in Diatom PSI-FCPI upon P700 Cation Formation. J Phys Chem B 2020; 124:1481-1486. [DOI: 10.1021/acs.jpcb.0c00715] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Ryo Nagao
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Makio Yokono
- Innovation Center, Nippon Flour Mills Company Ltd., Atsugi 243-0041, Japan
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, Kobe 657-8501, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Kobe 657-8501, Japan
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26
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Furukawa R, Aso M, Fujita T, Akimoto S, Tanaka R, Tanaka A, Yokono M, Takabayashi A. Formation of a PSI-PSII megacomplex containing LHCSR and PsbS in the moss Physcomitrella patens. JOURNAL OF PLANT RESEARCH 2019; 132:867-880. [PMID: 31541373 DOI: 10.1007/s10265-019-01138-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/08/2019] [Indexed: 05/10/2023]
Abstract
Mosses are one of the earliest land plants that diverged from fresh-water green algae. They are considered to have acquired a higher capacity for thermal energy dissipation to cope with dynamically changing solar irradiance by utilizing both the "algal-type" light-harvesting complex stress-related (LHCSR)-dependent and the "plant-type" PsbS-dependent mechanisms. It is hypothesized that the formation of photosystem (PS) I and II megacomplex is another mechanism to protect photosynthetic machinery from strong irradiance. Herein, we describe the analysis of the PSI-PSII megacomplex from the model moss, Physcomitrella patens, which was resolved using large-pore clear-native polyacrylamide gel electrophoresis (lpCN-PAGE). The similarity in the migration distance of the Physcomitrella PSI-PSII megacomplex to the Arabidopsis megacomplex shown during lpCN-PAGE suggested that the Physcomitrella PSI-PSII and Arabidopsis megacomplexes have similar structures. Time-resolved chlorophyll fluorescence measurements show that excitation energy was rapidly and efficiently transferred from PSII to PSI, providing evidence of an ordered association of the two photosystems. We also found that LHCSR and PsbS co-migrated with the Physcomitrella PSI-PSII megacomplex. The megacomplex showed pH-dependent chlorophyll fluorescence quenching, which may have been induced by LHCSR and/or PsbS proteins with the collaboration of zeaxanthin. We discuss the mechanism that regulates the energy distribution balance between two photosystems in Physcomitrella.
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Affiliation(s)
- Ryo Furukawa
- Institute of Low-Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819, Japan
| | - Michiki Aso
- Institute of Low-Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819, Japan
| | - Tomomichi Fujita
- Faculty of Science, Hokkaido University, N10 W8 Kita-ku, Sapporo, 060-0810, Japan
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Ryouichi Tanaka
- Institute of Low-Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819, Japan
| | - Ayumi Tanaka
- Institute of Low-Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819, Japan
| | - Makio Yokono
- Institute of Low-Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819, Japan.
- Innovation Center, Nippon Flour Mills Co., Ltd., Atsugi, 243-0041, Japan.
| | - Atsushi Takabayashi
- Institute of Low-Temperature Science, Hokkaido University, N19 W8 Kita-ku, Sapporo, 060-0819, Japan
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27
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Nagao R, Ueno Y, Yokono M, Shen JR, Akimoto S. Effects of excess light energy on excitation-energy dynamics in a pennate diatom Phaeodactylum tricornutum. PHOTOSYNTHESIS RESEARCH 2019; 141:355-365. [PMID: 30993504 DOI: 10.1007/s11120-019-00639-4] [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: 01/07/2019] [Accepted: 04/04/2019] [Indexed: 05/12/2023]
Abstract
Controlling excitation energy flow is a fundamental ability of photosynthetic organisms to keep a better performance of photosynthesis. Among the organisms, diatoms have unique light-harvesting complexes, fucoxanthin chlorophyll (Chl) a/c-binding proteins. We have recently investigated light-adaptation mechanisms of a marine centric diatom, Chaetoceros gracilis, by spectroscopic techniques. However, it remains unclear how pennate diatoms regulate excitation energy under different growth light conditions. Here, we studied light-adaptation mechanisms in a marine pennate diatom Phaeodactylum tricornutum grown at 30 µmol photons m-2 s-1 and further incubated for 24 h either in the dark, or at 30 or 300 µmol photons m-2 s-1 light intensity, by time-resolved fluorescence (TRF) spectroscopy. The high-light incubated cells showed no detectable oxygen-evolving activity of photosystem II, indicating the occurrence of a severe photodamage. The photodamaged cells showed alterations of steady-state absorption and fluorescence spectra and TRF spectra compared with the dark and low-light adapted cells. In particular, excitation-energy quenching is significantly accelerated in the photodamaged cells as shown by mean lifetime analysis of the Chl fluorescence. These spectral changes by the high-light treatment may result from arrangements of pigment-protein complexes to maintain the photosynthetic performance under excess light illumination. These growth-light dependent spectral properties in P. tricornutum are largely different from those in C. gracilis, thus providing insights into the different light-adaptation mechanisms between the pennate and centric diatoms.
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Affiliation(s)
- Ryo Nagao
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Makio Yokono
- Nippon Flour Mills Co., Ltd, Innovation Center, Atsugi, 243-0041, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan.
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