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Che Y, Fan D, Teng Z, Yao T, Wang Z, Zhang H, Sun G, Zhang H, Chow WS. Potassium alleviates over-reduction of the photosynthetic electron transport chain and helps to maintain photosynthetic function under salt-stress. PHYSIOLOGIA PLANTARUM 2023; 175:e13981. [PMID: 37616008 DOI: 10.1111/ppl.13981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 05/11/2023] [Accepted: 07/15/2023] [Indexed: 08/25/2023]
Abstract
Potassium ions enhance photosynthetic tolerance to salt stress. We hypothesized that potassium ions, by minimizing the trans-thylakoid proton diffusion potential difference, can alleviate over-reduction of the photosynthetic electron transport chain and maintain the functionality of the photosynthetic apparatus. This study investigated the effects of exogenous potassium on the transcription level and activity of proteins related to the photosynthetic electron-transport chain of tobacco seedlings under salt stress. Salt stress retarded the growth of seedlings and caused an outflow of potassium ions from the chloroplast. It also lowered qP (indicator of the oxidation state of QA , the primary quinone electron acceptor in Photosystem II (PSII) and YPSII (average photochemical yield of PSII in the light-adapted state) while increasing YNO+NF (nonregulatory energy dissipation in functional and nonfunctional PSII), accompanied by decreased expression of most light-harvesting, energy-transduction, and electron-transport genes. However, exogenous potassium prevented these effects due to NaCl. Interestingly, lincomycin (an inhibitor of the synthesis of chloroplast-encoded proteins in PSII) significantly diminished the alleviation effect of exogenous potassium on salt stress. We attribute the comprehensive NaCl-induced downregulation of transcription and photosynthetic activities to retrograde signaling induced by reactive oxygen species. There probably exist at least two types of retrograde signaling induced by reactive oxygen species, distinguished by their sensitivity to lincomycin. Exogenous potassium appears to exert its primary effect by ameliorating the trans-thylakoid proton diffusion potential difference via a potassium channel, thereby accelerating ATP synthesis and carbon assimilation, alleviating over-reduction of the photosynthetic electron transport chain, and maintaining the functionality of photosynthetic proteins.
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Affiliation(s)
- Yanhui Che
- College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Dayong Fan
- College of Forestry, Beijing Forestry University, Beijing, China
| | - Zhiyuan Teng
- College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Tongtong Yao
- College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Zihan Wang
- College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Hongbo Zhang
- College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Guangyu Sun
- College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Huihui Zhang
- College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Wah Soon Chow
- Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, Australia
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2
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Furutani R, Ohnishi M, Mori Y, Wada S, Miyake C. The difficulty of estimating the electron transport rate at photosystem I. JOURNAL OF PLANT RESEARCH 2022; 135:565-577. [PMID: 34778922 DOI: 10.1007/s10265-021-01357-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
It is still a controversial issue how the electron transport reaction is carried out around photosystem I (PSI) in the photosynthetic electron transport chain. The measurable component in PSI is the oxidized P700, the reaction center chlorophyll in PSI, as the absorbance changes at 820-830 nm. Previously, the quantum yield at PSI [Y(I)] has been estimated as the existence probability of the photo-oxidizable P700 by applying the saturated-pulse illumination (SP; 10,000-20,000 µmol photons m-2 s-1). The electron transport rate (ETR) at PSI has been estimated from the Y(I) value, which was larger than the reaction rate at PSII, evaluated as the quantum yield of PSII, especially under stress-conditions such as CO2-limited and high light intensity conditions. Therefore, it has been considered that the extra electron flow at PSI was enhanced at the stress condition and played an important role in dealing with the excessive light energy. However, some pieces of evidence were reported that the excessive electron flow at PSI would be ignorable from other aspects. In the present research, we confirmed that the Y(I) value estimated by the SP method could be easily misestimated by the limitation of the electron donation to PSI. Moreover, we estimated the quantitative turnover rate of P700+ by the light-to-dark transition. However, the turnover rate of P700 was much slower than the ETR at PSII. It is still hard to quantitatively estimate the ETR at PSI by the current techniques.
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Affiliation(s)
- Riu Furutani
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo, 102-0076, Japan
| | - Miho Ohnishi
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo, 102-0076, Japan
| | - Yuki Mori
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Shinya Wada
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo, 102-0076, Japan
| | - Chikahiro Miyake
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo, 102-0076, Japan.
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Order-of-magnitude enhancement in photocurrent generation of Synechocystis sp. PCC 6803 by outer membrane deprivation. Nat Commun 2022; 13:3067. [PMID: 35654796 PMCID: PMC9163127 DOI: 10.1038/s41467-022-30764-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 05/17/2022] [Indexed: 12/24/2022] Open
Abstract
Biophotovoltaics (BPV) generates electricity from reducing equivalent(s) produced by photosynthetic organisms by exploiting a phenomenon called extracellular electron transfer (EET), where reducing equivalent(s) is transferred to external electron acceptors. Although cyanobacteria have been extensively studied for BPV because of their high photosynthetic activity and ease of handling, their low EET activity poses a limitation. Here, we show an order-of-magnitude enhancement in photocurrent generation of the cyanobacterium Synechocystis sp. PCC 6803 by deprivation of the outer membrane, where electrons are suggested to stem from pathway(s) downstream of photosystem I. A marked enhancement of EET activity itself is verified by rapid reduction of exogenous electron acceptor, ferricyanide. The extracellular organic substances, including reducing equivalent(s), produced by this cyanobacterium serve as respiratory substrates for other heterotrophic bacteria. These findings demonstrate that the outer membrane is a barrier that limits EET. Therefore, depriving this membrane is an effective approach to exploit the cyanobacterial reducing equivalent(s). The low extracellular electron transfer activity hampers the application of cyanobacteria in biophotovoltaics. Here, the authors report an order-of-magnitude enhancement in photocurrent generation of the cyanobacterium by deprivation of the outer cell membrane.
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Identification of a Novel Mutation Exacerbated the PSI Photoinhibition in pgr5/ pgrl1 Mutants; Caution for Overestimation of the Phenotypes in Arabidopsis pgr5-1 Mutant. Cells 2021; 10:cells10112884. [PMID: 34831107 PMCID: PMC8616342 DOI: 10.3390/cells10112884] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 12/12/2022] Open
Abstract
PSI photoinhibition is usually avoided through P700 oxidation. Without this protective mechanism, excess light represents a potentially lethal threat to plants. PGR5 is suggested to be a major component of cyclic electron transport around PSI and is important for P700 oxidation in angiosperms. The known Arabidopsis PGR5 deficient mutant, pgr5-1, is incapable of P700 oxidation regulation and has been used in numerous photosynthetic studies. However, here it was revealed that pgr5-1 was a double mutant with exaggerated PSI photoinhibition. pgr5-1 significantly reduced growth compared to the newly isolated PGR5 deficient mutant, pgr5hope1. The introduction of PGR5 into pgr5-1 restored P700 oxidation regulation, but remained a pale-green phenotype, indicating that pgr5-1 had additional mutations. Both pgr5-1 and pgr5hope1 tended to cause PSI photoinhibition by excess light, but pgr5-1 exhibited an enhanced reduction in PSI activity. Introducing AT2G17240, a candidate gene for the second mutation into pgr5-1 restored the pale-green phenotype and partially restored PSI activity. Furthermore, a deficient mutant of PGRL1 complexing with PGR5 significantly reduced PSI activity in the double-deficient mutant with AT2G17240. From these results, we concluded that AT2G17240, named PSI photoprotection 1 (PTP1), played a role in PSI photoprotection, especially in PGR5/PGRL1 deficient mutants.
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Oguchi R, Terashima I, Chow WS. The effect of different spectral light quality on the photoinhibition of Photosystem I in intact leaves. PHOTOSYNTHESIS RESEARCH 2021; 149:83-92. [PMID: 33404974 DOI: 10.1007/s11120-020-00805-z] [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: 08/30/2020] [Accepted: 11/20/2020] [Indexed: 05/13/2023]
Abstract
Light energy causes damage to Photosystem I (PSI) and Photosystem II (PSII). The majority of the previous photoinhibition studies have been conducted with PSII, which shows much larger photoinhibition than PSI; therefore, relatively little is known about the mechanism of PSI photoinhibition so far. A previous report showed that the photoinhibition action spectrum measured with PSI activity of isolated thylakoid is similar to the absorption spectrum of chlorophyll. However, it is known that the extent of PSI photoinhibition is much smaller in vivo compared to in vitro. It is also possible that the different extent of PSII photoinhibition, caused by different spectral light qualities, can affect the photoinhibition of PSI in vivo because PSI receives electrons from PSII. In the present research, to study the effect of light quality and the effect of the extent of PSII photoinhibition on the PSI photoinhibition in vivo, intact leaves were photoinhibited under four different light qualities. The rate coefficient of PSI photoinhibition was significantly higher in blue and red light compared to white light. The rate of PSI photoinhibition at the same photon-exposure was the largest in blue and red light and followed by white and green light. These results support the notion that light absorption by chlorophyll is responsible for the PSI photoinhibition, even in intact leaves. The variation among light colors in the relationships between the extent of photoinhibition of PSII and that of PSI indicate that PSI and PSII are independently photoinhibited with different mechanisms in the early stage of in vivo photoinhibition.
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Affiliation(s)
- Riichi Oguchi
- Department of Biological Sciences, School of Science, The University of Tokyo, 7‑3‑1 Hongo, Bunkyo‑ku, Tokyo, 113‑0033, Japan.
| | - Ichiro Terashima
- Department of Biological Sciences, School of Science, The University of Tokyo, 7‑3‑1 Hongo, Bunkyo‑ku, Tokyo, 113‑0033, Japan
| | - Wah Soon Chow
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
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Sakkos JK, Hernandez-Ortiz S, Osteryoung KW, Ducat DC. Orthogonal Degron System for Controlled Protein Degradation in Cyanobacteria. ACS Synth Biol 2021; 10:1667-1681. [PMID: 34232633 DOI: 10.1021/acssynbio.1c00035] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Synechococcus elongatus PCC 7942 is a model cyanobacterium for study of the circadian clock, photosynthesis, and bioproduction of chemicals, yet nearly 40% of its gene identities and functions remain unknown, in part due to limitations of the existing genetic toolkit. While classical techniques for the study of genes (e.g., deletion or mutagenesis) can yield valuable information about the absence of a gene and its associated protein, there are limits to these approaches, particularly in the study of essential genes. Herein, we developed a tool for inducible degradation of target proteins in S. elongatus by adapting a method using degron tags from the Mesoplasma florum transfer-mRNA (tmRNA) system. We observed that M. florum lon protease can rapidly degrade exogenous and native proteins tagged with the cognate sequence within hours of induction. We used this system to inducibly degrade the essential cell division factor, FtsZ, as well as shell protein components of the carboxysome. Our results have implications for carboxysome biogenesis and the rate of carboxysome turnover during cell growth. Lon protease control of proteins offers an alternative approach for the study of essential proteins and protein dynamics in cyanobacteria.
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Affiliation(s)
- Jonathan K. Sakkos
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
| | - Sergio Hernandez-Ortiz
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan 48824, United States
| | - Katherine W. Osteryoung
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, United States
| | - Daniel C. Ducat
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, United States
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
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7
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Ohnishi M, Furutani R, Sohtome T, Suzuki T, Wada S, Tanaka S, Ifuku K, Ueno D, Miyake C. Photosynthetic Parameters Show Specific Responses to Essential Mineral Deficiencies. Antioxidants (Basel) 2021; 10:996. [PMID: 34201487 PMCID: PMC8300717 DOI: 10.3390/antiox10070996] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 06/08/2021] [Accepted: 06/18/2021] [Indexed: 11/18/2022] Open
Abstract
In response to decreases in the assimilation efficiency of CO2, plants oxidize the reaction center chlorophyll (P700) of photosystem I (PSI) to suppress reactive oxygen species (ROS) production. In hydro-cultured sunflower leaves experiencing essential mineral deficiencies, we analyzed the following parameters that characterize PSI and PSII: (1) the reduction-oxidation states of P700 [Y(I), Y(NA), and Y(ND)]; (2) the relative electron flux in PSII [Y(II)]; (3) the reduction state of the primary electron acceptor in PSII, QA (1 - qL); and (4) the non-photochemical quenching of chlorophyll fluorescence (NPQ). Deficiency treatments for the minerals N, P, Mn, Mg, S, and Zn decreased Y(II) with an increase in the oxidized P700 [Y(ND)], while deficiencies for the minerals K, Fe, Ca, B, and Mo decreased Y(II) without an increase in Y(ND). During the induction of photosynthesis, the above parameters showed specific responses to each mineral. That is, we could diagnose the mineral deficiency and identify which mineral affected the photosynthesis parameters.
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Affiliation(s)
- Miho Ohnishi
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
| | - Riu Furutani
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
| | - Takayuki Sohtome
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
- Department of System Development, Bunkoukeiki Co. Ltd., 4-8 Takakura-machi, Hachioji-shi, Tokyo 192-0033, Japan
| | - Takeshi Suzuki
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
| | - Shinya Wada
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
| | - Soma Tanaka
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
| | - Kentaro Ifuku
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan;
| | - Daisei Ueno
- Graduate School of Integrated Arts and Science, Kochi University, 200 Otsu, Monobe, Nankoku 783-8502, Japan;
| | - Chikahiro Miyake
- Department of Applied Biological Science, Graduate School for Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (M.O.); (R.F.); (T.S.); (S.W.); (S.T.)
- Core Research for Environmental Science and Technology (CREST), Japan Science and Technology Agency (JST), 7 Gobancho, Tokyo 102-0076, Japan;
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Luu Trinh MD, Miyazaki D, Ono S, Nomata J, Kono M, Mino H, Niwa T, Okegawa Y, Motohashi K, Taguchi H, Hisabori T, Masuda S. The evolutionary conserved iron-sulfur protein TCR controls P700 oxidation in photosystem I. iScience 2021; 24:102059. [PMID: 33554065 PMCID: PMC7848650 DOI: 10.1016/j.isci.2021.102059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/08/2020] [Accepted: 01/08/2021] [Indexed: 11/21/2022] Open
Abstract
In natural habitats, plants have developed sophisticated regulatory mechanisms to optimize the photosynthetic electron transfer rate at the maximum efficiency and cope with the changing environments. Maintaining proper P700 oxidation at photosystem I (PSI) is the common denominator for most regulatory processes of photosynthetic electron transfers. However, the molecular complexes and cofactors involved in these processes and their function(s) have not been fully clarified. Here, we identified a redox-active chloroplast protein, the triplet-cysteine repeat protein (TCR). TCR shared similar expression profiles with known photosynthetic regulators and contained two triplet-cysteine motifs (CxxxCxxxC). Biochemical analysis indicated that TCR localizes in chloroplasts and has a [3Fe-4S] cluster. Loss of TCR limited the electron sink downstream of PSI during dark-to-light transition. Arabidopsis pgr5-tcr double mutant reduced growth significantly and showed unusual oxidation and reduction of plastoquinone pool. These results indicated that TCR is involved in electron flow(s) downstream of PSI, contributing to P700 oxidation. P700 oxidation at photosystem I is important for regulation of photosynthesis TCR is a redox active chloroplast protein harboring a 3Fe-4S iron-sulfur cluster TCR controls electron flow around photosystem I, contributing to P700 oxidation
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Affiliation(s)
- Mai Duy Luu Trinh
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Daichi Miyazaki
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Sumire Ono
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Jiro Nomata
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Masaru Kono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Hiroyuki Mino
- Division of Materials Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Tatsuya Niwa
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Yuki Okegawa
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Ken Motohashi
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Hideki Taguchi
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Shinji Masuda
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
- Corresponding author
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Shimakawa G, Hanawa H, Wada S, Hanke GT, Matsuda Y, Miyake C. Physiological Roles of Flavodiiron Proteins and Photorespiration in the Liverwort Marchantia polymorpha. FRONTIERS IN PLANT SCIENCE 2021; 12:668805. [PMID: 34489990 PMCID: PMC8418088 DOI: 10.3389/fpls.2021.668805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/30/2021] [Indexed: 05/19/2023]
Abstract
Against the potential risk in oxygenic photosynthesis, that is, the generation of reactive oxygen species, photosynthetic electron transport needs to be regulated in response to environmental fluctuations. One of the most important regulations is keeping the reaction center chlorophyll (P700) of photosystem I in its oxidized form in excess light conditions. The oxidation of P700 is supported by dissipating excess electrons safely to O2, and we previously found that the molecular mechanism of the alternative electron sink is changed from flavodiiron proteins (FLV) to photorespiration in the evolutionary history from cyanobacteria to plants. However, the overall picture of the regulation of photosynthetic electron transport is still not clear in bryophytes, the evolutionary intermediates. Here, we investigated the physiological roles of FLV and photorespiration for P700 oxidation in the liverwort Marchantia polymorpha by using the mutants deficient in FLV (flv1) at different O2 partial pressures. The effective quantum yield of photosystem II significantly decreased at 2kPa O2 in flv1, indicating that photorespiration functions as the electron sink. Nevertheless, it was clear from the phenotype of flv1 that FLV was dominant for P700 oxidation in M. polymorpha. These data suggested that photorespiration has yet not replaced FLV in functioning for P700 oxidation in the basal land plant probably because of the lower contribution to lumen acidification, compared with FLV, as reflected in the results of electrochromic shift analysis.
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Affiliation(s)
- Ginga Shimakawa
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Research Center for Solar Energy Chemistry, Osaka University, Suita, Japan
- Department of Biosciences, School of Biological and Environmental Sciences, Kwansei-Gakuin University, Nishinomiya, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
| | - Hitomi Hanawa
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Shinya Wada
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
| | - Guy T. Hanke
- School of Biochemistry and Chemistry, Queen Mary University of London, London, United Kingdom
| | - Yusuke Matsuda
- Department of Biosciences, School of Biological and Environmental Sciences, Kwansei-Gakuin University, Nishinomiya, Japan
| | - Chikahiro Miyake
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
- *Correspondence: Chikahiro Miyake,
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Furutani R, Makino A, Suzuki Y, Wada S, Shimakawa G, Miyake C. Intrinsic Fluctuations in Transpiration Induce Photorespiration to Oxidize P700 in Photosystem I. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1761. [PMID: 33322777 PMCID: PMC7763966 DOI: 10.3390/plants9121761] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/04/2020] [Accepted: 12/04/2020] [Indexed: 01/30/2023]
Abstract
Upon exposure to environmental stress, the primary electron donor in photosystem I (PSI), P700, is oxidized to suppress the production of reactive oxygen species that could oxidatively inactivate the function of PSI. The illumination of rice leaves with actinic light induces intrinsic fluctuations in the opening and closing of stomata, causing the net CO2 assimilation rate to fluctuate. We examined the effects of these intrinsic fluctuations on electron transport reactions. Under atmospheric O2 conditions (21 kPa), the effective quantum yield of photosystem II (PSII) (Y(II)) remained relatively high while the net CO2 assimilation rate fluctuated, which indicates the function of alternative electron flow. By contrast, under low O2 conditions (2 kPa), Y(II) fluctuated. These results suggest that photorespiration primarily drove the alternative electron flow. Photorespiration maintained the oxidation level of ferredoxin (Fd) throughout the fluctuation of the net CO2 assimilation rate. Moreover, the relative activity of photorespiration was correlated with both the oxidation level of P700 and the magnitude of the proton gradient across the thylakoid membrane in 21 kPa O2 conditions. These results show that photorespiration oxidized P700 by stimulating the proton gradient formation when CO2 assimilation was suppressed by stomatal closure.
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Affiliation(s)
- Riu Furutani
- Graduate School for Agricultural Sciences, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (R.F.); (S.W.)
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Tokyo 102-0076, Japan; (A.M.); (Y.S.); (G.S.)
| | - Amane Makino
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Tokyo 102-0076, Japan; (A.M.); (Y.S.); (G.S.)
- Graduate School of Agriculture Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba, Sendai 980-8572, Japan
| | - Yuij Suzuki
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Tokyo 102-0076, Japan; (A.M.); (Y.S.); (G.S.)
- Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan
| | - Shinya Wada
- Graduate School for Agricultural Sciences, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (R.F.); (S.W.)
| | - Ginga Shimakawa
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Tokyo 102-0076, Japan; (A.M.); (Y.S.); (G.S.)
- Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8631, Japan
| | - Chikahiro Miyake
- Graduate School for Agricultural Sciences, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan; (R.F.); (S.W.)
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Tokyo 102-0076, Japan; (A.M.); (Y.S.); (G.S.)
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Wada S, Miyake C, Makino A, Suzuki Y. Photorespiration Coupled With CO 2 Assimilation Protects Photosystem I From Photoinhibition Under Moderate Poly(Ethylene Glycol)-Induced Osmotic Stress in Rice. FRONTIERS IN PLANT SCIENCE 2020; 11:1121. [PMID: 32849689 PMCID: PMC7396556 DOI: 10.3389/fpls.2020.01121] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 07/07/2020] [Indexed: 05/31/2023]
Abstract
Photorespiration coupled with CO2 assimilation is thought to act as a defense system against photoinhibition caused by osmotic stress. In the present study, we examined whether such a mechanism is operative for the protection of photosystem I (PSI) in rice (Oryza sativa L.) including transgenic plants with decreased and increased Rubisco content (RBCS-antisense and RBCS-sense plants, respectively). All plants were hydroponically grown and moderate osmotic stress was imposed using hydroponic culture solutions containing poly(ethylene glycol) (PEG) at 16% or 20% (w/v) for 2 d. In wild-type plants, the rates of CO2 assimilation (A) were significantly decreased by the PEG treatment, whereas the photorespiration activity estimated from the rates of electron transport in photosystem II (PSII) and A were not affected. The maximal quantum efficiency of PSII (F v/F m) and the maximal activity of PSI (P m) were also not affected. In RBCS-antisense plants, A and the estimated photorespiration activity were considerably lower than those in wild-type plants in the presence or absence of the PEG treatment. P m and both F v/F m and P m decreased in the 16% PEG-treated and 20% PEG-treated RBCS-antisense plants, respectively. Thus, the decrease in Rubisco content led to the photoinhibition of PSI and PSII, indicating the importance of photorespiration coupled with CO2 assimilation for the protection of PSI from moderate PEG-induced osmotic stress. It was also shown that PSI was more sensitive to osmotic stress than PSII. In the PEG-treated wild-type and RBCS-antisense plants, osmotic-stress responses of the photosynthetic electron transport reactions upstream of PSI led to the oxidation of P700, which is thought to prevent PSI from over-reduction. Although such a defense system operated, it was not sufficient for the protection of PSI in RBCS-antisense plants. In addition, there were no large differences in the parameters measured between wild-type and RBCS-sense plants, as overproduction of Rubisco did not increase photorespiration activity.
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Affiliation(s)
- Shinya Wada
- Faculty of Agriculture, Iwate University, Morioka, Japan
- Graduate School of Agricultural Science, Kobe University, Nada-ku, Japan
| | - Chikahiro Miyake
- Graduate School of Agricultural Science, Kobe University, Nada-ku, Japan
| | - Amane Makino
- Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Japan
| | - Yuji Suzuki
- Faculty of Agriculture, Iwate University, Morioka, Japan
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Molecular Mechanism of Oxidation of P700 and Suppression of ROS Production in Photosystem I in Response to Electron-Sink Limitations in C3 Plants. Antioxidants (Basel) 2020; 9:antiox9030230. [PMID: 32168828 PMCID: PMC7139980 DOI: 10.3390/antiox9030230] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 02/28/2020] [Accepted: 03/04/2020] [Indexed: 02/01/2023] Open
Abstract
Photosynthesis fixes CO2 and converts it to sugar, using chemical-energy compounds of both NADPH and ATP, which are produced in the photosynthetic electron transport system. The photosynthetic electron transport system absorbs photon energy to drive electron flow from Photosystem II (PSII) to Photosystem I (PSI). That is, both PSII and PSI are full of electrons. O2 is easily reduced to a superoxide radical (O2-) at the reducing side, i.e., the acceptor side, of PSI, which is the main production site of reactive oxygen species (ROS) in photosynthetic organisms. ROS-dependent inactivation of PSI in vivo has been reported, where the electrons are accumulated at the acceptor side of PSI by artificial treatments: exposure to low temperature and repetitive short-pulse (rSP) illumination treatment, and the accumulated electrons flow to O2, producing ROS. Recently, my group found that the redox state of the reaction center of chlorophyll P700 in PSI regulates the production of ROS: P700 oxidation suppresses the production of O2- and prevents PSI inactivation. This is why P700 in PSI is oxidized upon the exposure of photosynthesis organisms to higher light intensity and/or low CO2 conditions, where photosynthesis efficiency decreases. In this study, I introduce a new molecular mechanism for the oxidation of P700 in PSI and suppression of ROS production from the robust relationship between the light and dark reactions of photosynthesis. The accumulated protons in the lumenal space of the thylakoid membrane and the accumulated electrons in the plastoquinone (PQ) pool drive the rate-determining step of the P700 photo-oxidation reduction cycle in PSI from the photo-excited P700 oxidation to the reduction of the oxidized P700, thereby enhancing P700 oxidation.
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Growth under Fluctuating Light Reveals Large Trait Variation in a Panel of Arabidopsis Accessions. PLANTS 2020; 9:plants9030319. [PMID: 32138306 PMCID: PMC7154841 DOI: 10.3390/plants9030319] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/18/2020] [Indexed: 11/21/2022]
Abstract
The oxidation of P700 in photosystem I (PSI) is a robust mechanism that suppresses the production of reactive oxygen species. We researched the contribution of photorespiration to the oxidation of P700 in wheat leaves. We analyzed the effects of changes in partial pressures of CO2 and O2 on photosynthetic parameters. The electron flux in photosynthetic linear electron flow (LEF) exhibited a positive linear relationship with an origin of zero against the dissipation rate (vH+) of electrochromic shift (ECS; ΔpH across thylakoid membrane), indicating that cyclic electron flow around PSI did not contribute to H+ usage in photosynthesis/photorespiration. The vH+ showed a positive linear relationship with an origin of zero against the H+ consumption rates in photosynthesis/photorespiration (JgH+). These two linear relationships show that the electron flow in LEF is very efficiently coupled with H+ usage in photosynthesis/photorespiration. Lowering the intercellular partial pressure of CO2 enhanced the oxidation of P700 with the suppression of LEF. Under photorespiratory conditions, the oxidation of P700 and the reduction of the plastoquinone pool were stimulated with a decrease in JgH+, compared to non-photorespiratory conditions. These results indicate that the reduction-induced suppression of electron flow (RISE) suppresses the reduction of oxidized P700 in PSI under photorespiratory conditions. Furthermore, under photorespiratory conditions, ECS was larger and H+ conductance was lower against JgH+ than those under non-photorespiratory conditions. These results indicate that photorespiration enhances RISE and ΔpH formation by lowering H+ conductance, both of which contribute to keeping P700 in a highly oxidized state.
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Wada S, Takagi D, Miyake C, Makino A, Suzuki Y. Responses of the Photosynthetic Electron Transport Reactions Stimulate the Oxidation of the Reaction Center Chlorophyll of Photosystem I, P700, under Drought and High Temperatures in Rice. Int J Mol Sci 2019; 20:ijms20092068. [PMID: 31027369 PMCID: PMC6539619 DOI: 10.3390/ijms20092068] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 04/24/2019] [Accepted: 04/24/2019] [Indexed: 12/14/2022] Open
Abstract
It is of interest how photosynthetic electron transport (PET) reactions respond to excess light energy caused by the combination of drought stress and high temperatures. Since such information is scarcely available for photosystem I (PSI), this question was explored in rice (Oryza sativa L.) plants subjected to drought stress, using culture solutions that contain poly(ethylene glycol) at different concentrations under two day/night temperature regimes. At 27/22 °C (day/night), drought stress led to the oxidation of the reaction center of the chlorophyll of PSI (P700), and also led to decreases in the quantum efficiencies of photosystem II (PSII) and PSI, and a reduction of the primary quinone electron acceptor of PSI. Such drought stress responses were wholly stimulated at 35/30 °C. These parameters were strongly correlated with each other and were minimally affected by temperature. These results indicate that the drought stress responses of the respective PET reactions are closely associated with each other in the oxidization of P700 and that such responses are stimulated at high temperatures. The underlying mechanisms of these phenomena were discussed. While P700 oxidation is thought to suppress reactive oxygen species (ROS) production, PSI photoinhibition was observed under severe stress conditions, implying that P700 oxidation is not sufficient for the protection of PSI under drought stress.
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Affiliation(s)
- Shinya Wada
- Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan.
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
| | - Daisuke Takagi
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
- Graduate School of Agricultural Science, Tohoku University, Aramaki-Aoba 468-1, Aoba-ku, Sendai 980-8572, Japan.
| | - Chikahiro Miyake
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan.
| | - Amane Makino
- Graduate School of Agricultural Science, Tohoku University, Aramaki-Aoba 468-1, Aoba-ku, Sendai 980-8572, Japan.
| | - Yuji Suzuki
- Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan.
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Takagi D, Ihara H, Takumi S, Miyake C. Growth Light Environment Changes the Sensitivity of Photosystem I Photoinhibition Depending on Common Wheat Cultivars. FRONTIERS IN PLANT SCIENCE 2019; 10:686. [PMID: 31214216 PMCID: PMC6557977 DOI: 10.3389/fpls.2019.00686] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 05/07/2019] [Indexed: 05/09/2023]
Abstract
Light is an important factor for determining photosynthetic performance in land plants. At high light intensity, land plants develop photosynthetic activity by increasing electron sinks, such as the Calvin cycle and photorespiration and photoprotective mechanisms in photosystem II (PSII), to effectively utilize light and protect them from photoinhibition. In addition to PSII, photosystem I (PSI) has a risk of undergoing photoinhibition under high light intensity because of the reactive oxygen species (ROS) produced within PSI. However, the acclimation response has hardly been evaluated in the relationship of PSI photoprotection to growth light. In this study, we studied the effect of growth light intensity on the photoprotective mechanisms in PSI using six wheat cultivars. To evaluate the susceptibility of PSI to its photoinhibition, we used the repetitive short-pulse (rSP) illumination method to cause O2-dependent PSI photoinhibition. We found that PSI photoinhibition induced by rSP illumination was much more alleviated in wheat cultivars grown under high-light conditions compared to those grown under low-light conditions. Here, we observed that wheat plant grown under high-light conditions lowered the susceptibility of PSI to its photoinhibition compared to those grown under low-light conditions. Furthermore, the acclimation response toward PSI photoinhibition was significantly different among the studied wheat cultivars, although the quantum yields both of PSII and PSI were increased by high-light acclimation in all wheat cultivars as reported previously. Interestingly, we observed that total chlorophyll content in leaves correlated with the susceptibility of PSI to its photoinhibition. On the basis of these results, we suggest that high-light acclimation induces protection mechanisms against PSI photoinhibition in land plants, and the increase in the leaf chlorophyll content relates to the susceptibility of PSI photoinhibition in wheat plants.
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Affiliation(s)
- Daisuke Takagi
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
| | - Hiroaki Ihara
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Shigeo Takumi
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
- *Correspondence: Chikahiro Miyake,
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16
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Shimakawa G, Miyake C. Oxidation of P700 Ensures Robust Photosynthesis. FRONTIERS IN PLANT SCIENCE 2018; 9:1617. [PMID: 30459798 PMCID: PMC6232666 DOI: 10.3389/fpls.2018.01617] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/18/2018] [Indexed: 05/18/2023]
Abstract
In the light, photosynthetic cells can potentially suffer from oxidative damage derived from reactive oxygen species. Nevertheless, a variety of oxygenic photoautotrophs, including cyanobacteria, algae, and plants, manage their photosynthetic systems successfully. In the present article, we review previous research on how these photoautotrophs safely utilize light energy for photosynthesis without photo-oxidative damage to photosystem I (PSI). The reaction center chlorophyll of PSI, P700, is kept in an oxidized state in response to excess light, under high light and low CO2 conditions, to tune the light utilization and dissipate the excess photo-excitation energy in PSI. Oxidation of P700 is co-operatively regulated by a number of molecular mechanisms on both the electron donor and acceptor sides of PSI. The strategies to keep P700 oxidized are diverse among a variety of photoautotrophs, which are evolutionarily optimized for their ecological niche.
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Affiliation(s)
- Ginga Shimakawa
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
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17
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Shimakawa G, Shaku K, Miyake C. Reduction-Induced Suppression of Electron Flow (RISE) Is Relieved by Non-ATP-Consuming Electron Flow in Synechococcus elongatus PCC 7942. Front Microbiol 2018; 9:886. [PMID: 29867800 PMCID: PMC5949335 DOI: 10.3389/fmicb.2018.00886] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 04/18/2018] [Indexed: 01/13/2023] Open
Abstract
Photosynthetic organisms oxidize P700 to suppress the production of reactive oxygen species (ROS) in photosystem I (PSI) in response to the lower efficiency of photosynthesis under high light and low CO2 conditions. Previously, we found a positive relationship between reduction of plastoquinone (PQ) pool and oxidation of P700, which we named reduction-induced suppression of electron flow (RISE). In the RISE model, we proposed that the highly reduced state of the PQ pool suppresses Q-cycle turnover to oxidize P700 in PSI. Here, we tested whether RISE was relieved by the oxidation of the PQ pool, but not by the dissipation of the proton gradient (ΔpH) across the thylakoid membrane. Formation of ΔpH can also suppress electron flow to P700, because acidification on the luminal side of the thylakoid membrane lowers oxidation of reduced PQ in the cytochrome b6/f complex. We drove photosynthetic electron transport using H2O2-scavenging peroxidase reactions. Peroxidase reduces H2O2 with electron donors regenerated along the photosynthetic electron transport system, thereby promoting the formation of ΔpH. Addition of H2O2 to the cyanobacterium Synechococcus elongatus PCC 7942 under low CO2 conditions induced photochemical quenching of chlorophyll fluorescence, enhanced NADPH fluorescence and reduced P700. Thus, peroxidase reactions relieved the RISE mechanism, indicating that P700 oxidation can be induced only by the reduction of PQ to suppress the production of ROS in PSI. Overall, our data suggest that RISE regulates the redox state of P700 in PSI in cooperation with ΔpH regulation.
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Affiliation(s)
- Ginga Shimakawa
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Keiichiro Shaku
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, Kobe, Japan.,Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
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18
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High-throughput interaction screens illuminate the role of c-di-AMP in cyanobacterial nighttime survival. PLoS Genet 2018; 14:e1007301. [PMID: 29608558 PMCID: PMC5897029 DOI: 10.1371/journal.pgen.1007301] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 04/12/2018] [Accepted: 03/08/2018] [Indexed: 11/19/2022] Open
Abstract
The broadly conserved signaling nucleotide cyclic di-adenosine monophosphate (c-di-AMP) is essential for viability in most bacteria where it has been studied. However, characterization of the cellular functions and metabolism of c-di-AMP has largely been confined to the class Bacilli, limiting our functional understanding of the molecule among diverse phyla. We identified the cyclase responsible for c-di-AMP synthesis and characterized the molecule’s role in survival of darkness in the model photosynthetic cyanobacterium Synechococcus elongatus PCC 7942. In addition to the use of traditional genetic, biochemical, and proteomic approaches, we developed a high-throughput genetic interaction screen (IRB-Seq) to determine pathways where the signaling nucleotide is active. We found that in S. elongatus c-di-AMP is produced by an enzyme of the diadenylate cyclase family, CdaA, which was previously unexplored experimentally. A cdaA-null mutant experiences increased oxidative stress and death during the nighttime portion of day-night cycles, in which potassium transport is implicated. These findings suggest that c-di-AMP is biologically active in cyanobacteria and has non-canonical roles in the phylum including oxidative stress management and day-night survival. The pipeline and analysis tools for IRB-Seq developed for this study constitute a quantitative high-throughput approach for studying genetic interactions. Cyclic di-adenosine monophosphate (c-di-AMP) is a molecule that has significant roles in many microorganisms. This work shows the existence of c-di-AMP for the first time in photosynthetic microorganisms, cyanobacteria, and demonstrates its role in survival during the light-to-dark shifts that occur in day-night cycles. Despite the obvious importance of adaptation to these daily cycles for organisms that are fundamentally reliant on light, such as cyanobacteria, understanding of diurnal physiology is lacking because most cyanobacterial research is conducted during growth in constant light. To identify other players in c-di-AMP’s function we developed a low-cost and efficient method for finding interactions between genes. The technique combines one mutation, in this case for the gene that encodes the enzyme for synthesis of c-di-AMP, with thousands of other individual mutations to find pairwise interactions that affect fitness of the resulting mutants. Mutants are tagged with DNA barcodes to allow their survival to be easily tracked in a population of cells. The method enables us to place the function of c-di-AMP within the context of pathways previously known to be involved in day-night survival. Taken together, this work expands the known roles of c-di-AMP, improves our understanding of cyanobacterial survival in day-night cycles, and presents an improved approach for determining genetic interactions.
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19
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Shimakawa G, Watanabe S, Miyake C. A Carbon Dioxide Limitation-Inducible Protein, ColA, Supports the Growth of Synechococcus sp. PCC 7002. Mar Drugs 2017; 15:md15120390. [PMID: 29244744 PMCID: PMC5742850 DOI: 10.3390/md15120390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/30/2017] [Accepted: 12/09/2017] [Indexed: 11/16/2022] Open
Abstract
A limitation in carbon dioxide (CO₂), which occurs as a result of natural environmental variation, suppresses photosynthesis and has the potential to cause photo-oxidative damage to photosynthetic cells. Oxygenic phototrophs have strategies to alleviate photo-oxidative damage to allow life in present atmospheric CO₂ conditions. However, the mechanisms for CO₂ limitation acclimation are diverse among the various oxygenic phototrophs, and many mechanisms remain to be discovered. In this study, we found that the gene encoding a CO₂ limitation-inducible protein, ColA, is required for the cyanobacterium Synechococcus sp. PCC 7002 (S. 7002) to acclimate to limited CO₂ conditions. An S. 7002 mutant deficient in ColA (ΔcolA) showed lower chlorophyll content, based on the amount of nitrogen, than that in S. 7002 wild-type (WT) under ambient air but not high CO₂ conditions. Both thermoluminescence and protein carbonylation detected in the ambient air grown cells indicated that the lack of ColA promotes oxidative stress in S. 7002. Alterations in the photosynthetic O₂ evolution rate and relative electron transport rate in the short-term response, within an hour, to CO₂ limitation were the same between the WT and ΔcolA. Conversely, these photosynthetic parameters were mostly lower in the long-term response of a few days in ΔcolA than in the WT. These data suggest that ColA is required to sustain photosynthetic activity for living under ambient air in S. 7002. The unique phylogeny of ColA revealed diverse strategies to acclimate to CO₂ limitation among cyanobacteria.
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Affiliation(s)
- Ginga Shimakawa
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
| | - Satoru Watanabe
- Department of Bioscience, Tokyo University of Agriculture, Tokyo 156-8502, Japan.
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
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Shimakawa G, Matsuda Y, Nakajima K, Tamoi M, Shigeoka S, Miyake C. Diverse strategies of O 2 usage for preventing photo-oxidative damage under CO 2 limitation during algal photosynthesis. Sci Rep 2017; 7:41022. [PMID: 28106164 PMCID: PMC5247695 DOI: 10.1038/srep41022] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 12/15/2016] [Indexed: 12/20/2022] Open
Abstract
Photosynthesis produces chemical energy from photon energy in the photosynthetic electron transport and assimilates CO2 using the chemical energy. Thus, CO2 limitation causes an accumulation of excess energy, resulting in reactive oxygen species (ROS) which can cause oxidative damage to cells. O2 can be used as an alternative energy sink when oxygenic phototrophs are exposed to high light. Here, we examined the responses to CO2 limitation and O2 dependency of two secondary algae, Euglena gracilis and Phaeodactylum tricornutum. In E. gracilis, approximately half of the relative electron transport rate (ETR) of CO2-saturated photosynthesis was maintained and was uncoupled from photosynthesis under CO2 limitation. The ETR showed biphasic dependencies on O2 at high and low O2 concentrations. Conversely, in P. tricornutum, most relative ETR decreased in parallel with the photosynthetic O2 evolution rate in response to CO2 limitation. Instead, non-photochemical quenching was strongly activated under CO2 limitation in P. tricornutum. The results indicate that these secondary algae adopt different strategies to acclimatize to CO2 limitation, and that both strategies differ from those utilized by cyanobacteria and green algae. We summarize the diversity of strategies for prevention of photo-oxidative damage under CO2 limitation in cyanobacterial and algal photosynthesis.
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Affiliation(s)
- Ginga Shimakawa
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Yusuke Matsuda
- Research Center for the Development of Intelligent Self-Organized Biomaterials, Research Center for Environmental Bioscience, Department of Bioscience, Kwansei-Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Kensuke Nakajima
- Research Center for the Development of Intelligent Self-Organized Biomaterials, Research Center for Environmental Bioscience, Department of Bioscience, Kwansei-Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Masahiro Tamoi
- Department of Advanced Bioscience, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Shigeru Shigeoka
- Department of Advanced Bioscience, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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21
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Shimakawa G, Akimoto S, Ueno Y, Wada A, Shaku K, Takahashi Y, Miyake C. Diversity in photosynthetic electron transport under [CO 2]-limitation: the cyanobacterium Synechococcus sp. PCC 7002 and green alga Chlamydomonas reinhardtii drive an O 2-dependent alternative electron flow and non-photochemical quenching of chlorophyll fluorescence during CO 2-limited photosynthesis. PHOTOSYNTHESIS RESEARCH 2016; 130:293-305. [PMID: 27026083 DOI: 10.1007/s11120-016-0253-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 03/22/2016] [Indexed: 06/05/2023]
Abstract
Some cyanobacteria, but not all, experience an induction of alternative electron flow (AEF) during CO2-limited photosynthesis. For example, Synechocystis sp. PCC 6803 (S. 6803) exhibits AEF, but Synechococcus elongatus sp. PCC 7942 does not. This difference is due to the presence of flavodiiron 2 and 4 proteins (FLV2/4) in S. 6803, which catalyze electron donation to O2. In this study, we observed a low-[CO2] induced AEF in the marine cyanobacterium Synechococcus sp. PCC 7002 that lacks FLV2/4. The AEF shows high affinity for O2, compared with AEF mediated by FLV2/4 in S. 6803, and can proceed under extreme low [O2] (about a few µM O2). Further, the transition from CO2-saturated to CO2-limited photosynthesis leads a preferential excitation of PSI to PSII and increased non-photochemical quenching of chlorophyll fluorescence. We found that the model green alga Chlamydomonas reinhardtii also has an O2-dependent AEF showing the same affinity for O2 as that in S. 7002. These data represent the diverse molecular mechanisms to drive AEF in cyanobacteria and green algae. In this paper, we further discuss the diversity, the evolution, and the physiological function of strategy to CO2-limitation in cyanobacterial and green algal photosynthesis.
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Affiliation(s)
- Ginga Shimakawa
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan.
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
- Molecular Photoscience Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
| | - Ayumi Wada
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
| | - Keiichiro Shaku
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
| | - Yuichiro Takahashi
- Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama, 700-8530, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
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22
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Holland SC, Artier J, Miller NT, Cano M, Yu J, Ghirardi ML, Burnap RL. Impacts of genetically engineered alterations in carbon sink pathways on photosynthetic performance. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.09.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Takagi D, Hashiguchi M, Sejima T, Makino A, Miyake C. Photorespiration provides the chance of cyclic electron flow to operate for the redox-regulation of P700 in photosynthetic electron transport system of sunflower leaves. PHOTOSYNTHESIS RESEARCH 2016; 129:279-90. [PMID: 27116126 DOI: 10.1007/s11120-016-0267-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/18/2016] [Indexed: 05/24/2023]
Abstract
To elucidate the molecular mechanism to oxidize the reaction center chlorophyll, P700, in PSI, we researched the effects of partial pressure of O2 (pO2) on photosynthetic characteristic parameters in sunflower (Helianthus annuus L.) leaves. Under low CO2 conditions, the oxidation of P700 was stimulated; however the decrease in pO2 suppressed its oxidation. Electron fluxes in PSII [Y(II)] and PSI [Y(I)] showed pO2-dependence at low CO2 conditions. H(+)-consumption rate, estimated from Y(II) and CO2-fixation/photorespiration rates (JgH(+)), showed the positive curvature relationship with the dissipation rate of electrochromic shift signal (V H (+) ), which indicates H(+)-efflux rate from lumen to stroma in chloroplasts. Therefore, these electron fluxes contained, besides CO2-fixation/photorespiration-dependent electron fluxes, non-H(+)-consumption electron fluxes including Mehler-ascorbate peroxidase (MAP)-pathway. Y(I) that was larger than Y(II) surely implies the functioning of cyclic electron flow (CEF). Both MAP-pathway and CEF were suppressed at lower pO2, with plastoquinone-pool reduced. That is, photorespiration prepares the redox-poise of photosynthetic electron transport system for CEF activity as an electron sink. Excess Y(II), [ΔY(II)] giving the curvature relationship with V H (+) , and excess Y(I) [ΔCEF] giving the difference between Y(I) and Y(II) were used as an indicator of MAP-pathway and CEF activity, respectively. Although ΔY(II) was negligible and did not show positive relationship to the oxidation-state of P700, ΔCEF showed positive linear relationship to the oxidation-state of P700. These facts indicate that CEF cooperatively with photorespiration regulates the redox-state of P700 to suppress the over-reduction in PSI under environmental stress conditions.
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Affiliation(s)
- Daisuke Takagi
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Masaki Hashiguchi
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Takehiro Sejima
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Amane Makino
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai, 981-8555, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
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Takagi D, Takumi S, Hashiguchi M, Sejima T, Miyake C. Superoxide and Singlet Oxygen Produced within the Thylakoid Membranes Both Cause Photosystem I Photoinhibition. PLANT PHYSIOLOGY 2016; 171:1626-34. [PMID: 26936894 PMCID: PMC4936555 DOI: 10.1104/pp.16.00246] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/01/2016] [Indexed: 05/18/2023]
Abstract
Photosystem I (PSI) photoinhibition suppresses plant photosynthesis and growth. However, the mechanism underlying PSI photoinhibition has not been fully clarified. In this study, in order to investigate the mechanism of PSI photoinhibition in higher plants, we applied repetitive short-pulse (rSP) illumination, which causes PSI-specific photoinhibition in chloroplasts isolated from spinach leaves. We found that rSP treatment caused PSI photoinhibition, but not PSII photoinhibition in isolated chloroplasts in the presence of O2 However, chloroplastic superoxide dismutase and ascorbate peroxidase activities failed to protect PSI from its photoinhibition. Importantly, PSI photoinhibition was largely alleviated in the presence of methyl viologen, which stimulates the production of reactive oxygen species (ROS) at the stromal region by accepting electrons from PSI, even under the conditions where CuZn-superoxide dismutase and ascorbate peroxidase activities were inactivated by KCN. These results suggest that the ROS production site, but not the ROS production rate, is critical for PSI photoinhibition. Furthermore, we found that not only superoxide (O2 (-)) but also singlet oxygen ((1)O2) is involved in PSI photoinhibition induced by rSP treatment. From these results, we suggest that PSI photoinhibition is caused by both O2 (-) and (1)O2 produced within the thylakoid membranes when electron carriers in PSI become highly reduced. Here, we show, to our knowledge, new insight into the PSI photoinhibition in higher plants.
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Affiliation(s)
- Daisuke Takagi
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan (D.T., S.T., M.H., T.S., C.M.); andCore Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan (C.M.)
| | - Shigeo Takumi
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan (D.T., S.T., M.H., T.S., C.M.); andCore Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan (C.M.)
| | - Masaki Hashiguchi
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan (D.T., S.T., M.H., T.S., C.M.); andCore Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan (C.M.)
| | - Takehiro Sejima
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan (D.T., S.T., M.H., T.S., C.M.); andCore Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan (C.M.)
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan (D.T., S.T., M.H., T.S., C.M.); andCore Research for Environmental Science and Technology, Japan Science and Technology Agency, 7 Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan (C.M.)
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Mano J, Endo T, Miyake C. How do photosynthetic organisms manage light stress? A tribute to the late Professor Kozi Asada. PLANT & CELL PHYSIOLOGY 2016; 57:1351-1353. [PMID: 27903805 DOI: 10.1093/pcp/pcw116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Jun'ichi Mano
- Science Research Center, Yamaguchi University, Yoshida 1677-1, Yamaguchi, 753-8515, Japan
| | - Tsuyoshi Endo
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Chikahiro Miyake
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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