1
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Jimbo H, Wada H. Deacylation of galactolipids decomposes photosystem II dimers to enhance degradation of damaged D1 protein. PLANT PHYSIOLOGY 2023; 191:87-95. [PMID: 36189956 PMCID: PMC9806619 DOI: 10.1093/plphys/kiac460] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/02/2022] [Indexed: 05/28/2023]
Abstract
Photosystem II (PSII) contains many lipid molecules that are essential for the function and maintenance of PSII. Under strong light conditions, PSII complexes are dynamically modified during the repair process; however, the molecular mechanism of the dynamic changes in the PSII structure is still unclear. In the present study, we investigated the role of a lipase in the repair of PSII in Synechocystis sp. PCC 6803. We identified a protein encoded by the sll1969 gene, previously named lipase A (lipA), in the Synechocystis sp. PCC 6803 genome as a candidate for the lipase involved in PSII repair. Recombinant protein expressed in Escherichia coli cells hydrolyzed fatty acids at the sn-1 position of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol as well as triacylglycerol esterified with stearic acids. PSII repair in a disrupted mutant of the lipA gene was suppressed by the slow degradation of damaged D1 protein under strong light. The level of the PSII dimer remained higher in lipA mutant cells than wild-type (WT) cells under strong light. LipA protein was associated with the PSII dimer in vivo, and recombinant LipA protein decomposed PSII dimers purified from WT cells to monomers by reducing MGDG content in the PSII complex. These results indicate that LipA reacts with PSII dimers, dissociates them into monomers by digesting MGDG, and enhances D1 degradation during PSII repair.
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Affiliation(s)
- Haruhiko Jimbo
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Hajime Wada
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
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2
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Do motor plans affect sensorimotor state estimates during temporal decision-making with crossed vs. uncrossed hands? Failure to replicate the dynamic crossed-hand effect. Exp Brain Res 2022; 240:1529-1545. [PMID: 35332358 DOI: 10.1007/s00221-022-06349-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 03/10/2022] [Indexed: 11/04/2022]
Abstract
Hermosillo et al. (J Neurosci 31: 10019-10022, 2011) have suggested that action planning of hand movements impacts decisions about the temporal order judgments regarding vibrotactile stimulation of the hands. Specifically, these authors reported that the crossed-hand effect, a confusion about which hand is which when held in a crossed posture, gradually reverses some 320 ms before the arms begin to move from an uncrossed to a crossed posture or vice versa, such that the crossed-hand is reversed at the time of movement onset in anticipation of the movement's end position. However, to date, no other study has attempted to replicate this dynamic crossed-hand effect. Therefore, in the present study, we conducted four experiments to revisit the question whether preparing uncrossed-to-crossed or crossed-to-uncrossed movements affects the temporo-spatial perception of tactile stimulation of the hands. We used a temporal order judgement (TOJ) task at different time stages during action planning to test whether TOJs are more difficult with crossed than uncrossed hands ("static crossed-hand effect") and, crucially, whether planning to cross or uncross the hands shows the opposite pattern of difficulties ("dynamic crossed-hand effect"). As expected, our results confirmed the static crossed-hand effect. However, the dynamic crossed-hand effect could not be replicated. In addition, we observed that participants delayed their movements with late somatosensory stimulation from the TOJ task, even when the stimulations were meaningless, suggesting that the TOJ task resulted in cross-modal distractions. Whereas the current findings are not inconsistent with a contribution of motor signals to posture perception, they cast doubt on observations that motor signals impact state estimates well before movement onset.
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3
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Lewis CM, Flory JD, Moore TA, Moore AL, Rittmann BE, Vermaas WFJ, Torres CI, Fromme P. Electrochemically Driven Photosynthetic Electron Transport in Cyanobacteria Lacking Photosystem II. J Am Chem Soc 2022; 144:2933-2942. [PMID: 35157427 DOI: 10.1021/jacs.1c09291] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Light-activated photosystem II (PSII) carries out the critical step of splitting water in photosynthesis. However, PSII is susceptible to light-induced damage. Here, results are presented from a novel microbial electro-photosynthetic system (MEPS) that uses redox mediators in conjunction with an electrode to drive electron transport in live Synechocystis (ΔpsbB) cells lacking PSII. MEPS-generated, light-dependent current increased with light intensity up to 2050 μmol photons m-2 s-1, which yielded a delivery rate of 113 μmol electrons h-1 mg-chl-1 and an average current density of 150 A m-2 s-1 mg-chl-1. P700+ re-reduction kinetics demonstrated that initial rates exceeded wildtype PSII-driven electron delivery. The electron delivery occurs ahead of the cytochrome b6f complex to enable both NADPH and ATP production. This work demonstrates an electrochemical system that can drive photosynthetic electron transport, provides a platform for photosynthetic foundational studies, and has the potential for improving photosynthetic performance at high light intensities.
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Affiliation(s)
- Christine M Lewis
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States.,Biodesign Institute Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States.,Biodesign Institute Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
| | - Justin D Flory
- Biodesign Institute Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States.,Engineering Center for Negative Carbon Emmisions, at Arizona State University, Tempe, Arizona 85281, United States
| | - Thomas A Moore
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States.,Julie Ann Wrigley Global Institute of Sustainability and Innovation, Arizona State University, Tempe Arizona 85287, United States
| | - Ana L Moore
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States.,Julie Ann Wrigley Global Institute of Sustainability and Innovation, Arizona State University, Tempe Arizona 85287, United States
| | - Bruce E Rittmann
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287, United States.,Biodesign Institute Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
| | - Wim F J Vermaas
- School of Life Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - César I Torres
- Biodesign Institute Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States.,School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287, United States
| | - Petra Fromme
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States.,Biodesign Institute Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
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4
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Zhang J, Zhang Z, Liu W, Li L, Han L, Xu L, Zhao Y. Transcriptome Analysis Revealed a Positive Role of Ethephon on Chlorophyll Metabolism of Zoysia japonica under Cold Stress. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11030442. [PMID: 35161421 PMCID: PMC8839986 DOI: 10.3390/plants11030442] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/30/2022] [Accepted: 02/03/2022] [Indexed: 05/18/2023]
Abstract
Zoysia japonica is a warm-season turfgrass with a good tolerance and minimal maintenance requirements. However, its use in Northern China is limited due to massive chlorophyll loss in early fall, which is the main factor affecting its distribution and utilization. Although ethephon treatment at specific concentrations has reportedly improved stress tolerance and extended the green period in turfgrass, the potential mechanisms underlying this effect are not clear. In this study, we evaluated and analyzed chlorophyll changes in the physiology and transcriptome of Z. japonica plants in response to cold stress (4 °C) with and without ethephon pretreatment. Based on the transcriptome and chlorophyll content analysis, ethephon pretreatment increased the leaf chlorophyll content under cold stress by affecting two processes: the stimulation of chlorophyll synthesis by upregulating ZjMgCH2 and ZjMgCH3 expression; and the suppression of chlorophyll degradation by downregulating ZjPAO, ZjRCCR, and ZjSGR expression. Furthermore, ethephon pretreatment increased the ratio of chlorophyll a to chlorophyll b in the leaves under cold stress, most likely by suppressing the conversion of chlorophyll a to chlorophyll b due to decreased chlorophyll b synthesis via downregulation of ZjCAO. Additionally, the inhibition of chlorophyll b synthesis may result in energy redistribution between photosystem II and photosystem I.
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Affiliation(s)
- Jiahang Zhang
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
| | - Zhiwei Zhang
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
- CCTEG Ecological Environment Technology Co., Ltd., Beijing 100013, China
| | - Wen Liu
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
| | - Lijing Li
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
| | - Liebao Han
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
| | - Lixin Xu
- College of Grassland Science, Beijing Forestry University, Beijing 100083, China; (J.Z.); (Z.Z.); (W.L.); (L.L.); (L.H.)
- Correspondence: (L.X.); (Y.Z.)
| | - Yuhong Zhao
- Animal Science College, Tibet Agriculture & Animal Husbandry University, Nyingchi 860000, China
- Correspondence: (L.X.); (Y.Z.)
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5
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Sensitivity of Photosynthesis to Warming in Two Similar Species of the Aquatic Angiosperm Ruppia from Tropical and Temperate Habitats. SUSTAINABILITY 2021. [DOI: 10.3390/su13169433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Climate change-related events, such as marine heatwaves, are increasing seawater temperatures, thereby putting pressure on marine biota. The cosmopolitan distribution and significant contribution to marine primary production by the genus Ruppia makes them interesting organisms to study thermal tolerance and local adaptation. In this study, we investigated the photosynthetic responses in Ruppia to the predicted future warming in two contrasting bioregions, temperate Sweden and tropical Thailand. Through DNA barcoding, specimens were determined to Ruppia cirrhosa for Sweden and Ruppia maritima for Thailand. Photosynthetic responses were assessed using pulse amplitude-modulated fluorometry, firstly in short time incubations at 18, 23, 28, and 33 °C in the Swedish set-up and 28, 33, 38, and 43 °C in the Thai set-up. Subsequent experiments were conducted to compare the short time effects to longer, five-day incubations in 28 °C for Swedish plants and 40 °C for Thai plants. Swedish R. cirrhosa displayed minor response, while Thai R. maritima was more sensitive to both direct and prolonged temperature stress with a drastic decrease in the photosynthetic parameters leading to mortality. The results indicate that in predicted warming scenarios, Swedish R. cirrhosa may sustain an efficient photosynthesis and potentially outcompete more heat-sensitive species. However, populations of the similar R. maritima in tropical environments may suffer a decline as their productivity will be highly reduced.
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6
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Zavafer A. A theoretical framework of the hybrid mechanism of photosystem II photodamage. PHOTOSYNTHESIS RESEARCH 2021; 149:107-120. [PMID: 34338941 DOI: 10.1007/s11120-021-00843-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 05/04/2021] [Indexed: 06/13/2023]
Abstract
Photodamage of photosystem II is a significant physiological process that is prevalent in the fields of photobiology, photosynthesis research and plant/algal stress. Since its discovery, numerous efforts have been devoted to determine the causes and mechanisms of action of photosystem II photodamage. There are two contrasting hypotheses to explain photodamage: (1) the excitation pressure induced by light absorption by the photosynthetic pigments and (2) direct photodamage of the Mn cluster located at the water-splitting site, which is independent of excitation pressure. While these two hypotheses seemed mutually exclusive, during the last decade, several independent works have proposed an alternative approach indicating that both hypotheses are valid. This was termed the dual hypothesis of photosystem II photodamage, and it postulates that both excess excitation and direct Mn photodamage operate at the same time, independently or in a synergic manner, depending on the type of sample, temperature, light spectrum, or other environmental stressors. In this mini-review, a brief summary of the contrasting hypotheses is presented, followed by recapitulation of key discoveries in the field of photosystem II photodamage of the last decade, and a synthesis of how these works support a full hybrid framework (operation of several mechanisms and their permutations) to explain PSII photodamage. All these are in recognition of Prof. Wah Soon Chow (the Australian National University), one of the key proposers of the dual hypothesis.
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Affiliation(s)
- Alonso Zavafer
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia.
- Climate Change Cluster (C3), University of Technology Sydney, Sydney, NSW, 2007, Australia.
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7
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Carneiro M, Chini Zittelli G, Cicchi B, Touloupakis E, Faraloni C, Maia IB, Pereira H, Santos T, Malcata FX, Otero A, Varela J, Torzillo G. In situ monitoring of chlorophyll a fluorescence in Nannochloropsis oceanica cultures to assess photochemical changes and the onset of lipid accumulation during nitrogen deprivation. Biotechnol Bioeng 2021; 118:4375-4388. [PMID: 34319592 DOI: 10.1002/bit.27906] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/13/2021] [Accepted: 07/17/2021] [Indexed: 01/28/2023]
Abstract
In situ chlorophyll a fluorescence measurements were applied to monitor changes in the photochemical variables of Nannochloropsis oceanica cultures under nitrogen-deplete and nitrogen-replete (control) conditions. In addition, growth, lipid, fatty acid, and pigment contents were also followed. In the control culture, growth was promoted along with pigment content, electron transport rate (ETR), and polyunsaturated fatty acids, while total lipid content and fatty acid saturation level diminished. Under nitrogen-deplete conditions, the culture showed a higher de-epoxidation state of the xanthophyll cycle pigments. Fast transients revealed a poor processing efficiency for electron transfer beyond QA , which was in line with the low ETR due to nitrogen depletion. Lipid content and the de-epoxidation state were the first biochemical variables triggered by the change in nutrient status, which coincided with a 20% drop in the in situ effective quantum yield of PSII (ΔF'/Fm '), and a raise in the Vj measurements. A good correlation was found between the changes in ΔF'/Fm ' and lipid content (r = -0.96, p < 0.01). The results confirm the reliability and applicability of in situ fluorescence measurements to monitor lipid induction in N. oceanica.
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Affiliation(s)
- Mariana Carneiro
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering of the University of Porto, Porto, Portugal
| | | | - Bernardo Cicchi
- CNR-IBE-Consiglio Nazionale delle Ricerche-Istituto per la BioEconomia, Florence, Italy
| | - Eleftherios Touloupakis
- CNR-IRET - Consiglio Nazionale delle Ricerche-Istituto di Ricerca sugli Ecosistemi Terrestri, Florence, Italy
| | - Cecilia Faraloni
- CNR-IBE-Consiglio Nazionale delle Ricerche-Istituto per la BioEconomia, Florence, Italy
| | - Inês B Maia
- CCMAR-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Hugo Pereira
- Green Colab-Associação Oceano Verde, University of Algarve, Campus de Gambelas, Faro, Portugal
| | - Tamára Santos
- CCMAR-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Francisco X Malcata
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering of the University of Porto, Porto, Portugal
| | - Ana Otero
- USC-Instituto de Acuicultura and Departamento de Microbiología y Parasitología, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - João Varela
- CCMAR-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Giuseppe Torzillo
- CNR-IBE-Consiglio Nazionale delle Ricerche-Istituto per la BioEconomia, Florence, Italy.,CIMAR-Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San José, Costa Rica
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8
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Light factors and nitrogen availability to enhance biomass and C-phycocyanin productivity of Thermosynechococcus sp. CL-1. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2020.107899] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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9
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Rac M, Shumbe L, Oger C, Guy A, Vigor C, Ksas B, Durand T, Havaux M. Luminescence imaging of leaf damage induced by lipid peroxidation products and its modulation by β-cyclocitral. PHYSIOLOGIA PLANTARUM 2021; 171:246-259. [PMID: 33215689 DOI: 10.1111/ppl.13279] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/30/2020] [Accepted: 11/09/2020] [Indexed: 05/26/2023]
Abstract
Lipid peroxidation is a primary event associated with oxidative stress in plants. This phenomenon secondarily generates bioactive and/or toxic compounds such as reactive carbonyl species (RCS), phytoprostanes, and phytofurans, as confirmed here in Arabidopsis plants exposed to photo-oxidative stress conditions. We analyzed the effects of exogenous applications of secondary lipid oxidation products on Arabidopsis plants by luminescence techniques. Oxidative damage to attached leaves was measured by autoluminescence imaging, using a highly sensitive CCD camera, and the activity of the detoxification pathway, dependent on the transcription regulator SCARECROW-LIKE 14 (SCL14), was monitored with a bioluminescent line expressing the firefly LUCIFERASE (LUC) gene under the control of the ALKENAL REDUCTASE (AER) gene promoter. We identified 4-hydroxynonenal (HNE), and to a lesser extent 4-hydroxyhexenal (HHE), as highly reactive compounds that are harmful to leaves and can trigger AER gene expression, contrary to other RCS (pentenal, hexenal) and to isoprostanoids. Although the levels of HNE and other RCS were enhanced in the SCL14-deficient mutant (scl14), exogenously applied HNE was similarly damaging to this mutant, its wild-type parent and a SCL14-overexpressing transgenic line (OE:SCL14). However, strongly boosting the SCL14 detoxification pathway and AER expression by a pre-treatment of OE:SCL14 with the signaling apocarotenoid β-cyclocitral canceled the damaging effects of HNE. Conversely, in the scl14 mutant, the effects of β-cyclocitral and HNE were additive, leading to enhanced leaf damage. These results indicate that the cellular detoxification pathway induced by the low-toxicity β-cyclocitral targets highly toxic compounds produced during lipid peroxidation, reminiscent of a safener-type mode of action.
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Affiliation(s)
- Marek Rac
- Institute of Biosciences and Biotechnologies, CEA/Cadarache, Aix Marseille University, CEA, CNRS, BIAM, UMR7265, Saint-Paul-lez-Durance, France
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Leonard Shumbe
- Institute of Biosciences and Biotechnologies, CEA/Cadarache, Aix Marseille University, CEA, CNRS, BIAM, UMR7265, Saint-Paul-lez-Durance, France
| | - Camille Oger
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, University of Montpellier, Montpellier, France
| | - Alexandre Guy
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, University of Montpellier, Montpellier, France
| | - Claire Vigor
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, University of Montpellier, Montpellier, France
| | - Brigitte Ksas
- Institute of Biosciences and Biotechnologies, CEA/Cadarache, Aix Marseille University, CEA, CNRS, BIAM, UMR7265, Saint-Paul-lez-Durance, France
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247, CNRS, University of Montpellier, Montpellier, France
| | - Michel Havaux
- Institute of Biosciences and Biotechnologies, CEA/Cadarache, Aix Marseille University, CEA, CNRS, BIAM, UMR7265, Saint-Paul-lez-Durance, France
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10
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Tripathi D, Rai KK, Pandey-Rai S. Impact of green synthesized WcAgNPs on in-vitro plant regeneration and withanolides production by inducing key biosynthetic genes in Withania coagulans. PLANT CELL REPORTS 2021; 40:283-299. [PMID: 33151379 DOI: 10.1007/s00299-020-02630-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/17/2020] [Indexed: 06/11/2023]
Abstract
Withania coagulans (L.) Dunal bio-synthesized silver nanoparticles (WcAgNPs) worked as an abiotic elicitor or auto-catalyst that enhanced root regeneration and withanolides production in in-vitro regenerated W. coagulans. Rapid development in the production / consumption of silver nanoparticles (AgNPs) raised serious concern over its effects on the growth of natural plant community. The knowledge related to impact of AgNPs on plant growth and biocompatibility is increasing day by day, but comprehensive mechanism and gaps regarding their impacts on plant health have yet to be addressed. In the present study, we investigated the impact of Withania coagulans biosynthesized AgNPs (WcAgNPs) on in-vitro plant growth and withanolides production. Obtained results showed that the low concentrations of WcAgNPs significantly induced the plant growth by regulating oxidative stress via anti-oxidative defense system. Physiological, morphology and anatomical features also reflected healthy plant growth under low WcAgNPs exposure. While higher concentrations of WcAgNPs have a negative impact on W. coagulans plant growth due to induced lipid peroxidation, ROS accumulation, and root cell death. At lower concentrations, WcAgNPs have shown a positive effect on in-planta withanolides biosynthesis stimulating withanolide A and withaferin A up to 11.15-22.8-fold, respectively. Furthermore, the expression of withanolides biosynthetic genes were also quantified upon WcAgNPs exposure and terpenes biosynthetic genes showed over-expression. Thus, the present study concludes that the lower concentrations of WcAgNPs positively induced plant growth via improved root organogenesis and also have potential to act as an elicitor for withanolides production.
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Affiliation(s)
- Deepika Tripathi
- Laboratory of Morphogenesis, Department of Botany, Institute of Science, Banaras Hindu University (BHU), Varanasi, 221005, Uttar Pradesh, India
| | - Krishna Kumar Rai
- Laboratory of Morphogenesis, Department of Botany, Institute of Science, Banaras Hindu University (BHU), Varanasi, 221005, Uttar Pradesh, India
| | - Shashi Pandey-Rai
- Laboratory of Morphogenesis, Department of Botany, Institute of Science, Banaras Hindu University (BHU), Varanasi, 221005, Uttar Pradesh, India.
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11
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Xin X, Huang G, An C, Lu C, Xiong W. Exploring the biophysicochemical alteration of green alga Asterococcus superbus interactively affected by nanoparticles, triclosan and illumination. JOURNAL OF HAZARDOUS MATERIALS 2020; 398:122855. [PMID: 32473326 DOI: 10.1016/j.jhazmat.2020.122855] [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: 02/09/2020] [Revised: 04/07/2020] [Accepted: 05/02/2020] [Indexed: 06/11/2023]
Abstract
Toxic effects on Asterococcus superbus were studied based on different combinations of P25-TiO2, nano-ZnO and triclosan under multiple illumination conditions. A full factorial design (2 × 2×2 × 3) was implemented to explore interactive effects, and to identify significant factors. The results showed illumination is the most important factor with significance and becomes one of the main reasons to affect chlorophyll pigments, photosynthesis activity, unsaturated fatty acids, mitochondria function, and cause oxidative stress. Triclosan considerably affects cell viability, photosynthesis activity, lipid peroxidation and protein structure, for which triclosan is more significant than nano-ZnO. P25 is significant for oxidative stress, antioxidant enzyme, and lipid peroxidation. P25 * nano-ZnO is the only significant interaction of pollutants, affecting macromolecules, lipid peroxidation, and photosynthesis activity. High-order interactions play significant roles in affecting multiple molecular components. Two groups of endpoints are best to reflect alga responses to interactively effects from P25, nano-ZnO, and triclosan. One is ROS, chlorophyll pigments, TBARS, area, MTT, and MMP, and the other one is chlorophyll pigments, ROS, TBARS, CAT, MTT and SOD. Our findings can be instructive for a comprehensive comparison among interactions of multiple pollutants and environmental factors in natural waters, such that more robust environmental toxicity analyses can be performed.
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Affiliation(s)
- Xiaying Xin
- Department of Civil Engineering, Memorial University of Newfoundland, St. John's, A1C 5S7, Canada; Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, S4S 0A2, Canada
| | - Gordon Huang
- Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, S4S 0A2, Canada.
| | - Chunjiang An
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, H3G 1M8, Canada
| | - Chen Lu
- Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, S4S 0A2, Canada
| | - Wenhui Xiong
- Stantec Consulting Ltd., Saskatoon, S7K 0K3, Canada
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12
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Yanhui C, Hongrui W, Beining Z, Shixing G, Zihan W, Yue W, Huihui Z, Guangyu S. Elevated air temperature damage to photosynthetic apparatus alleviated by enhanced cyclic electron flow around photosystem I in tobacco leaves. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 204:111136. [PMID: 32798755 DOI: 10.1016/j.ecoenv.2020.111136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
High temperature can lead to increased production of excess light energy, thus reducing photosynthetic capacity in plants. Photosynthetic cyclic electron flow (CEF) in photosystem I (PSI) can effectively protect photosystems, but its physiological mechanism under high temperature is poorly understood. In this study, antimycin A (AA) and thenoyltrifluoroacetone (TTFA) were used to inhibit PGR5-and NDH-dependent CEF pathways, respectively, to reveal the photoprotective functions of CEF for PSII in tobacco leaves under high temperature stress (37 °C, HT). High temperatures caused decreases in maximal photochemistry efficiency (Fv/Fm) and damaged photosystem II (PSII) in tobacco leaves. Under AA inhibition of PGR5-dependent CEF, high temperature increased the fluorescence intensity of point O (Fo) in OJIP curves, i.e., the energy absorption per active reaction center (ABS/RC), the trapping rate of the reaction center (TRo/RC), and the electron transport efficiency per reaction center (ETo/RC) in tobacco leaves. High temperature induced an increase in the hydrogen peroxide content and a decrease in pigment content in tobacco leaves. Under the high temperature treatment, inhibition of PGR5-dependent CEF reduced the activities of the PSII reaction center significantly, destroyed the oxygen-evolving complex (OEC), and impeded photosynthetic electron transfer from PSII to the plastoquinone (PQ) pool in tobacco leaves. The TTFA treatment inhibited the NDH-dependent pathway under high temperature conditions, with the relative fluorescence intensity of point I (VI) decreased significantly, and the content of hydrogen peroxide and superoxide anion increased significantly. Additionally, Fo and the redox degree of the PSII donor side (Wk) increased, and pigment content decreased compared to the control, but with little change compared to high temperature treatment, indicating that the inhibition of the NDH-dependent pathway directly weakened the capacity of the PQ pool to lead to the accumulation of reactive oxygen species (ROS) in tobacco leaves. In conclusion, CEF alleviated damage to the photosynthetic apparatus in tobacco leaves by increasing PSII heat dissipation, reducing ROS production, and maintaining the stability of the PQ pool to accommodate photosynthetic electron flow.
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Affiliation(s)
- Che Yanhui
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China
| | - Wang Hongrui
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China
| | - Zhang Beining
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China
| | - Gao Shixing
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China
| | - Wang Zihan
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China
| | - Wang Yue
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China
| | - Zhang Huihui
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China; College of Resources and Environment, Northeast Agricultural University, Harbin Heilongjiang, China
| | - Sun Guangyu
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China.
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Long-Chain Saturated Fatty Acids, Palmitic and Stearic Acids, Enhance the Repair of Photosystem II. Int J Mol Sci 2020; 21:ijms21207509. [PMID: 33053769 PMCID: PMC7589413 DOI: 10.3390/ijms21207509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/02/2020] [Accepted: 10/11/2020] [Indexed: 01/06/2023] Open
Abstract
Free fatty acids (FFA) generated in cyanobacterial cells can be utilized for the biodiesel that is required for our sustainable future. The combination of FFA and strong light induces severe photoinhibition of photosystem II (PSII), which suppresses the production of FFA in cyanobacterial cells. In the present study, we examined the effects of exogenously added FFA on the photoinhibition of PSII in Synechocystis sp. PCC 6803. The addition of lauric acid (12:0) to cells accelerated the photoinhibition of PSII by inhibiting the repair of PSII and the de novo synthesis of D1. α-Linolenic acid (18:3) affected both the repair of and photodamage to PSII. Surprisingly, palmitic (16:0) and stearic acids (18:0) enhanced the repair of PSII by accelerating the de novo synthesis of D1 with the mitigation of the photoinhibition of PSII. Our results show chemical potential of FFA in the regulation of PSII without genetic manipulation.
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Roach T, Na CS, Stöggl W, Krieger-Liszkay A. The non-photochemical quenching protein LHCSR3 prevents oxygen-dependent photoinhibition in Chlamydomonas reinhardtii. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2650-2660. [PMID: 31943079 PMCID: PMC7210768 DOI: 10.1093/jxb/eraa022] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/13/2020] [Indexed: 05/18/2023]
Abstract
Non-photochemical quenching (NPQ) helps dissipate surplus light energy, preventing formation of reactive oxygen species (ROS). In Chlamydomonas reinhardtii, the thylakoid membrane protein LHCSR3 is involved in pH-dependent (qE-type) NPQ, lacking in the npq4 mutant. Preventing PSII repair revealed that npq4 lost PSII activity faster than the wild type (WT) in elevated O2, while no difference between strains was observed in O2-depleted conditions. Low Fv/Fm values remained 1.5 h after moving cells out of high light, and this qH-type quenching was independent of LHCSR3 and not accompanied by losses of maximum PSII activity. Culturing cells in historic O2 atmospheres (30-35%) increased the qE of cells, due to increased LHCSR1 and PsbS levels, and LHCSR3 in the WT, showing that atmospheric O2 tensions regulate qE capacity. Colony growth of npq4 was severely restricted at elevated O2, and npq4 accumulated more reactive electrophile species (RES) than the WT, which could damage PSI. Levels of PsaA (PSI) were lower in npq4 grown at 35% O2, while PsbA (PSII) levels remained stable. We conclude that even at high O2 concentrations, the PSII repair cycle is sufficient to maintain net levels of PSII. However, LHCSR3 has an important function in protecting PSI against O2-mediated damage, such as via RES.
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Affiliation(s)
- Thomas Roach
- Department of Botany and Centre for Molecular Biology Innsbruck, Leopold-Franzens-Universität-Innsbruck, Sternwartestraße 15, Innsbruck, Austria
- Correspondence:
| | - Chae Sun Na
- Department of Botany and Centre for Molecular Biology Innsbruck, Leopold-Franzens-Universität-Innsbruck, Sternwartestraße 15, Innsbruck, Austria
- Seed Conservation Research Division, Department of Seed Vault, Baekdudaegan National Arboretum, Munsu-ro, Chunyang-myeon, Bonghwa-gun, Gyeongsangbuk-do, Republic of Korea
| | - Wolfgang Stöggl
- Department of Botany and Centre for Molecular Biology Innsbruck, Leopold-Franzens-Universität-Innsbruck, Sternwartestraße 15, Innsbruck, Austria
| | - Anja Krieger-Liszkay
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
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15
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Posch BC, Kariyawasam BC, Bramley H, Coast O, Richards RA, Reynolds MP, Trethowan R, Atkin OK. Exploring high temperature responses of photosynthesis and respiration to improve heat tolerance in wheat. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5051-5069. [PMID: 31145793 DOI: 10.1093/jxb/erz257] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 05/21/2019] [Indexed: 06/09/2023]
Abstract
High temperatures account for major wheat yield losses annually and, as the climate continues to warm, these losses will probably increase. Both photosynthesis and respiration are the main determinants of carbon balance and growth in wheat, and both are sensitive to high temperature. Wheat is able to acclimate photosynthesis and respiration to high temperature, and thus reduce the negative affects on growth. The capacity to adjust these processes to better suit warmer conditions stands as a potential avenue toward reducing heat-induced yield losses in the future. However, much remains to be learnt about such phenomena. Here, we review what is known of high temperature tolerance in wheat, focusing predominantly on the high temperature responses of photosynthesis and respiration. We also identify the many unknowns that surround this area, particularly with respect to the high temperature response of wheat respiration and the consequences of this for growth and yield. It is concluded that further investigation into the response of photosynthesis and respiration to high temperature could present several methods of improving wheat high temperature tolerance. Extending our knowledge in this area could also lead to more immediate benefits, such as the enhancement of current crop models.
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Affiliation(s)
- Bradley C Posch
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Buddhima C Kariyawasam
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Helen Bramley
- Plant Breeding Institute, Sydney Institute of Agriculture & School of Life and Environmental Sciences, The University of Sydney, Narrabri, NSW, Australia
| | - Onoriode Coast
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | | | - Matthew P Reynolds
- Global Wheat Program, International Maize and Wheat Improvement Center (CIMMYT), Mexico City, Mexico
| | - Richard Trethowan
- Plant Breeding Institute, Sydney Institute of Agriculture & School of Life and Environmental Sciences, The University of Sydney, Narrabri, NSW, Australia
| | - Owen K Atkin
- ARC Centre of Excellence in Plant Energy Biology, Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
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16
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Roach T, Stöggl W, Baur T, Kranner I. Distress and eustress of reactive electrophiles and relevance to light stress acclimation via stimulation of thiol/disulphide-based redox defences. Free Radic Biol Med 2018; 122:65-73. [PMID: 29563047 DOI: 10.1016/j.freeradbiomed.2018.03.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 03/10/2018] [Accepted: 03/16/2018] [Indexed: 01/30/2023]
Abstract
Photosynthetic organisms suffering from light stress have to cope with an increased formation of reactive short-chain aldehydes. Singlet oxygen generated from highly-charged reaction centres can peroxidise the poly-unsaturated fatty acid (PUFA)-rich thylakoid membranes they are embedded in. Lipid peroxides decay to release α,β-unsaturated aldehydes that are reactive electrophile species (RES). Acrolein is one of the most abundant and reactive RES produced in chloroplasts. Here, in the model chlorophyte alga Chlamydomonas reinhardtii, a clear concentration-dependent "distress" induced by acrolein intoxication was observed in conjunction with depletion of the glutathione pool. The glutathione redox state (EGSSG/2GSH) strongly correlated (R2 = 0.95) with decreasing Fv/Fm values of chlorophyll fluorescence. However, treatment of C. reinhardtii with sub-toxic acrolein concentrations increased glutathione concentrations and raised the protein levels of a glutathione-S-transferase (GSTS1), mimicking the response to excess light, indicating that at lower concentrations, acrolein may contribute to high light acclimation, which could be interpreted as "eustress". Furthermore, similar patterns of chloroplastic protein carbonylation occurred under light stress and in response to exogenous acrolein. Priming cells by low doses of acrolein increased the alga's resistance to singlet oxygen. A RNA seq. analysis showed a large overlap in gene regulation under singlet oxygen and acrolein stresses. Particularly enriched were transcripts of enzymes involved in thiol/disulphide exchanges. Some of the genes are regulated by the SOR1 transcription factor, but acrolein treatment still induced an increase in glutathione contents and enhanced singlet oxygen tolerance of the sor1 mutant. The results support a role for RES in chloroplast-to-nucleus retrograde signalling during high light acclimation, with involvement of SOR1 and other pathways.
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Affiliation(s)
- Thomas Roach
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria.
| | - Wolfgang Stöggl
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Theresa Baur
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Ilse Kranner
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
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17
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Niewiadomska E, Brückner K, Mulisch M, Kruk J, Orzechowska A, Pilarska M, Luchowski R, Gruszecki WI, Krupinska K. Lack of tocopherols influences the PSII antenna and the functioning of photosystems under low light. JOURNAL OF PLANT PHYSIOLOGY 2018; 223:57-64. [PMID: 29499454 DOI: 10.1016/j.jplph.2018.02.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 02/02/2018] [Accepted: 02/04/2018] [Indexed: 06/08/2023]
Abstract
As tocopherols are expected to protect PSII against toxic singlet oxygen it is surprising that the null tocopherol mutant vte1 has been reported to show only a weak enhancement of photosystem II photoinhibition under high irradiance. Based on the view that singlet oxygen is formed also in unstressed conditions, such as low light (LL), we hypothesized that some defense strategies are activated in vte1 in these light conditions. In support for that we noted several symptoms of stress at PSII in the mutant under LL, by means of parameters of fast and slow kinetics of chlorophyll fluorescence and of changes in the relative contribution of PSII antenna in comparison to those of PSI. This was associated with a lower extent of phosphorylation of PSII core proteins (D1 and CP43). PSII RCs do not totally recover from stress in vte1 even after the nocturnal phase. As a clear compensation for the impeded performance of PSII in the vte1 we noted an increased quantum efficiency of PSI. A pronounced changes between WT and the vte1 mutant were also related to conformation of LHCII at the beginning of photoperiod, suggesting the absence of LHCII trimers in the mutant. The thylakoids thickness was similar in WT and vte1 under LL, but a pronounced unstacking of thylakoids was evoked by HL only in vte1. In conclusion, we postulate that action of 1O2 on PSII in vte1 leads to some permanent damage at PSII core and at LHCII already under LL.
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Affiliation(s)
- Ewa Niewiadomska
- The F. Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland
| | - Kathleen Brückner
- Leibniz Institute of Plant Biochemistry, Department of Cell and Metabolic Biology, Weinberg 3, 06120 Halle, Germany.
| | - Maria Mulisch
- Institute of Botany, Christian-Albrechts-University of Kiel, Olshausenstr, 40, 24098 Kiel, Germany.
| | - Jerzy Kruk
- Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland.
| | - Aleksandra Orzechowska
- Department of Medical Physics and Biophysics, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Reymonta 19, 30-059 Krakow, Poland.
| | - Maria Pilarska
- The F. Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Rafał Luchowski
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
| | - Wiesław I Gruszecki
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
| | - Karin Krupinska
- Institute of Botany, Christian-Albrechts-University of Kiel, Olshausenstr, 40, 24098 Kiel, Germany.
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18
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Ferrero-Serrano Á, Su Z, Assmann SM. Illuminating the role of the Gα heterotrimeric G protein subunit, RGA1, in regulating photoprotection and photoavoidance in rice. PLANT, CELL & ENVIRONMENT 2018; 41:451-468. [PMID: 29216416 DOI: 10.1111/pce.13113] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/19/2017] [Accepted: 11/21/2017] [Indexed: 05/22/2023]
Abstract
We studied physiological mechanisms of photoavoidance and photoprotection of a dwarf rice mutant with erect leaves, d1, in which the RGA1 gene, which encodes the Gα subunit of the heterotrimeric G protein, is non-functional. Leaves of d1 exhibit lower leaf temperature and higher photochemical reflectance index relative to wild type (WT), indicative of increased photoavoidance and more efficient light harvesting. RNA sequencing analysis of flag leaves revealed that messenger RNA levels of genes encoding heat shock proteins, enzymes associated with chlorophyll breakdown, and ROS scavengers were down-regulated in d1. By contrast, genes encoding proteins associated with light harvesting, Photosystem II, cyclic electron transport, Photosystem I, and chlorophyll biosynthesis were up-regulated in d1. Consistent with these observations, when WT and d1 plants were experimentally subjected to the same light intensity, d1 plants exhibited a greater capacity to dissipate excess irradiance (increased nonphotochemical quenching) relative to WT. The increased capacity in d1 for both photoavoidance and photoprotection reduced sustained photoinhibitory damage, as revealed by a higher Fv /Fm . We therefore propose RGA1 as a regulator of photoavoidance and photoprotection mechanisms in rice and highlight the prospect of exploiting modulation of heterotrimeric G protein signalling to increase these characteristics and improve the yield of cereals in the event of abiotic stress.
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Affiliation(s)
- Ángel Ferrero-Serrano
- Biology Department, Penn State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
| | - Zhao Su
- Biology Department, Penn State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
| | - Sarah M Assmann
- Biology Department, Penn State University, 208 Mueller Laboratory, University Park, PA, 16802, USA
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19
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Niu Y, Xiang Y. An Overview of Biomembrane Functions in Plant Responses to High-Temperature Stress. FRONTIERS IN PLANT SCIENCE 2018; 9:915. [PMID: 30018629 PMCID: PMC6037897 DOI: 10.3389/fpls.2018.00915] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/08/2018] [Indexed: 05/03/2023]
Abstract
Biological membranes are highly ordered structures consisting of mosaics of lipids and proteins. Elevated temperatures can directly and effectively change the properties of these membranes, including their fluidity and permeability, through a holistic effect that involves changes in the lipid composition and/or interactions between lipids and specific membrane proteins. Ultimately, high temperatures can alter microdomain remodeling and instantaneously relay ambient cues to downstream signaling pathways. Thus, dynamic membrane regulation not only helps cells perceive temperature changes but also participates in intracellular responses and determines a cell's fate. Moreover, due to the specific distribution of extra- and endomembrane elements, the plasma membrane (PM) and membranous organelles are individually responsible for distinct developmental events during plant adaptation to heat stress. This review describes recent studies that focused on the roles of various components that can alter the physical state of the plasma and thylakoid membranes as well as the crucial signaling pathways initiated through the membrane system, encompassing both endomembranes and membranous organelles in the context of heat stress responses.
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Affiliation(s)
- Yue Niu
- *Correspondence: Yue Niu, Yun Xiang,
| | - Yun Xiang
- *Correspondence: Yue Niu, Yun Xiang,
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20
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Rozentsvet O, Kosobryukhov A, Zakhozhiy I, Tabalenkova G, Nesterov V, Bogdanova E. Photosynthetic parameters and redox homeostasis of Artemisia santonica L. under conditions of Elton region. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 118:385-393. [PMID: 28710946 DOI: 10.1016/j.plaphy.2017.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/05/2017] [Accepted: 07/05/2017] [Indexed: 06/07/2023]
Abstract
Structural and functional parameters and redox homeostasis in leaves of Artemisia santonica L. under environment conditions of Elton lake (the southeast region of the European part of Russia) were measured. The highest photosynthetic apparatus (PA) activity in A. santonica leaves on CO2 gas exchange as well as the highest content of green pigments was observed in the morning. Maximum share of violaxanthin cycle key pigments - zeaxanthin (Zx) and antheraxanthin (Ax) was observed in the afternoon and decreased in the evening. Lipids/chlorophyll (Chl) ratio increased in the evening due to the decrease in Chl concentration, and content of linolenic acid (С18:3n3) was decreased in the middle of the day. The content of TBA-reacting products increased 1.4-fold in the middle of the day, and decreased approximately 2-fold in the evening. The decrease of the activity was observed in diurnal dynamics of superoxide dismutase (SOD) and polyphenol oxidase (PPO). Increased accumulation of phenols and flavonoids, as well as free amino acids (FAA) in A. santonica leaves was observed in the middle of the day. Thus, the ability of A. santonica plants to resist the soil salinization, high levels of solar illumination and temperature consists of a number of protectively-adaptive reactions of metabolic and photosynthetic control.
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Affiliation(s)
- Olga Rozentsvet
- Institute of Ecology of the Volga River Basin, Russian Academy of Sciences, 10 Komzina St., 445003 Togliatti, Russia.
| | - Anatoly Kosobryukhov
- Institute of Basic Biological Problems, Russian Academy of Sciences, 2 Institutskaya St., 142290 Pushchino, Moscow region, Russia
| | - Ilya Zakhozhiy
- Institute of Biology of the Komi Science Centre of the Ural Division, Russian Academy of Sciences, 8 Kommunisticheskaya St., 167982 Syktyvkar, Komi Republic, Russia
| | - Galina Tabalenkova
- Institute of Biology of the Komi Science Centre of the Ural Division, Russian Academy of Sciences, 8 Kommunisticheskaya St., 167982 Syktyvkar, Komi Republic, Russia
| | - Viktor Nesterov
- Institute of Ecology of the Volga River Basin, Russian Academy of Sciences, 10 Komzina St., 445003 Togliatti, Russia
| | - Elena Bogdanova
- Institute of Ecology of the Volga River Basin, Russian Academy of Sciences, 10 Komzina St., 445003 Togliatti, Russia
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21
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Kondo T, Pinnola A, Chen WJ, Dall'Osto L, Bassi R, Schlau-Cohen GS. Single-molecule spectroscopy of LHCSR1 protein dynamics identifies two distinct states responsible for multi-timescale photosynthetic photoprotection. Nat Chem 2017; 9:772-778. [PMID: 28754946 DOI: 10.1038/nchem.2818] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 06/02/2017] [Indexed: 11/08/2022]
Abstract
In oxygenic photosynthesis, light harvesting is regulated to safely dissipate excess energy and prevent the formation of harmful photoproducts. Regulation is known to be necessary for fitness, but the molecular mechanisms are not understood. One challenge has been that ensemble experiments average over active and dissipative behaviours, preventing identification of distinct states. Here, we use single-molecule spectroscopy to uncover the photoprotective states and dynamics of the light-harvesting complex stress-related 1 (LHCSR1) protein, which is responsible for dissipation in green algae and moss. We discover the existence of two dissipative states. We find that one of these states is activated by pH and the other by carotenoid composition, and that distinct protein dynamics regulate these states. Together, these two states enable the organism to respond to two types of intermittency in solar intensity-step changes (clouds and shadows) and ramp changes (sunrise), respectively. Our findings reveal key control mechanisms underlying photoprotective dissipation, with implications for increasing biomass yields and developing robust solar energy devices.
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Affiliation(s)
- Toru Kondo
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Alberta Pinnola
- Department of Biotechnology, University of Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Wei Jia Chen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Luca Dall'Osto
- Department of Biotechnology, University of Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Roberto Bassi
- Department of Biotechnology, University of Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
- Istituto per la Protezione delle Piante (IPP), Consiglio Nazionale delle Ricerche (CNR), Strada delle Cacce 73, 10135, Turin, Italy
| | - Gabriela S Schlau-Cohen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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Pospíšil P, Yamamoto Y. Damage to photosystem II by lipid peroxidation products. Biochim Biophys Acta Gen Subj 2017; 1861:457-466. [DOI: 10.1016/j.bbagen.2016.10.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/07/2016] [Accepted: 10/08/2016] [Indexed: 11/16/2022]
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23
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Yoshioka-Nishimura M. Close Relationships Between the PSII Repair Cycle and Thylakoid Membrane Dynamics. PLANT & CELL PHYSIOLOGY 2016; 57:1115-22. [PMID: 27017619 DOI: 10.1093/pcp/pcw050] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 02/26/2016] [Indexed: 05/10/2023]
Abstract
In chloroplasts, a three-dimensional network of thylakoid membranes is formed by stacked grana and interconnecting stroma thylakoids. The grana are crowded with photosynthetic proteins, where PSII-light harvesting complex II (LHCII) supercomplexes often show semi-crystalline arrays for efficient energy trapping, transfer and use. Although light is essential for photosynthesis, PSII is damaged by reactive oxygen species that are generated from primary photochemical reactions when plants are exposed to excess light. Because PSII complexes are embedded in the lipid bilayers of thylakoid membranes, their functions are affected by the conditions of the lipids. Electron paramagnetic resonance (EPR) spin trapping measurements showed that singlet oxygen was formed through peroxidation of thylakoid lipids, suggesting that lipid peroxidation can damage proteins, including the D1 protein. After photodamage, PSII is restored by a specific repair system in thylakoid membranes. In the PSII repair cycle, phosphorylation and dephosphorylation of the PSII proteins control the timing of PSII disassembly and subsequent degradation of the D1 protein. Under light stress, stacked grana turn into unstacked thylakoids with bent grana margins. These structural changes may be closely linked to the mechanisms of the PSII repair cycle because PSII can move more easily from the grana core to the stroma thylakoids through an expanded stromal gap between each thylakoid. Thus, plants modulate the structure of thylakoid membranes under high light to carry out efficient PSII repair. This review focuses on the behavior of the PSII complex and the active role of structural changes to thylakoid membranes under light stress.
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Affiliation(s)
- Miho Yoshioka-Nishimura
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
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Singlet oxygen production in Chlamydomonas reinhardtii under heat stress. Sci Rep 2016; 6:20094. [PMID: 26831215 PMCID: PMC4757480 DOI: 10.1038/srep20094] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 12/17/2015] [Indexed: 11/16/2022] Open
Abstract
In the current study, singlet oxygen formation by lipid peroxidation induced by heat stress (40 °C) was studied in vivo in unicellular green alga Chlamydomonas reinhardtii. Primary and secondary oxidation products of lipid peroxidation, hydroperoxide and malondialdehyde, were generated under heat stress as detected using swallow-tailed perylene derivative fluorescence monitored by confocal laser scanning microscopy and high performance liquid chromatography, respectively. Lipid peroxidation was initiated by enzymatic reaction as inhibition of lipoxygenase by catechol and caffeic acid prevented hydroperoxide formation. Ultra-weak photon emission showed formation of electronically excited species such as triplet excited carbonyl, which, upon transfer of excitation energy, leads to the formation of either singlet excited chlorophyll or singlet oxygen. Alternatively, singlet oxygen is formed by direct decomposition of hydroperoxide via Russell mechanisms. Formation of singlet oxygen was evidenced by the nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl detected by electron paramagnetic resonance spin-trapping spectroscopy and the imaging of green fluorescence of singlet oxygen sensor green detected by confocal laser scanning microscopy. Suppression of singlet oxygen formation by lipoxygenase inhibitors indicates that singlet oxygen may be formed via enzymatic lipid peroxidation initiated by lipoxygenase.
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Yamamoto Y. Born in 1949 in postwar Japan. PHOTOSYNTHESIS RESEARCH 2016; 127:25-32. [PMID: 25557391 DOI: 10.1007/s11120-014-0072-y] [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: 11/06/2014] [Accepted: 12/18/2014] [Indexed: 06/04/2023]
Abstract
In this article, I would like to look back at my life as a researcher of photosynthesis. I was born in 1949, and grew up and was educated in postwar Japan in the 1950s and 1960s. I have studied photosynthesis, in particular Photosystem II, after research experiences in the USA and UK. My study of Photosystem II has continued over 43 years until now. Through the present retrospection, I would like to suggest that all photosynthesis researchers, including the members of the "49ers", many other established scientists, and young students as well, should not simply stay in the lab working hard on their studies and writing papers; but should also do something for the public. People want to learn from us about many critical social issues such as the environment, food, energy and, most importantly, peace. I believe that our knowledge must form an important basis for people to take action to create a peaceful and harmonious human society.
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Affiliation(s)
- Yasusi Yamamoto
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
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Yamamoto Y. Quality Control of Photosystem II: The Mechanisms for Avoidance and Tolerance of Light and Heat Stresses are Closely Linked to Membrane Fluidity of the Thylakoids. FRONTIERS IN PLANT SCIENCE 2016; 7:1136. [PMID: 27532009 PMCID: PMC4969305 DOI: 10.3389/fpls.2016.01136] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/18/2016] [Indexed: 05/22/2023]
Abstract
When oxygenic photosynthetic organisms are exposed to excessive light and/or heat, Photosystem II is damaged and electron transport is blocked. In these events, reactive oxygen species, endogenous radicals and lipid peroxidation products generated by photochemical reaction and/or heat cause the damage. Regarding light stress, plants first dissipate excessive light energy captured by light-harvesting chlorophyll protein complexes as heat to avoid the hazards, but once light stress is unavoidable, they tolerate the stress by concentrating damage in a particular protein in photosystem II, i.e., the reaction-center binding D1 protein of Photosystem II. The damaged D1 is removed by specific proteases and replaced with a new copy produced through de novo synthesis (reversible photoinhibition). When light intensity becomes extremely high, irreversible aggregation of D1 occurs and thereby D1 turnover is prevented. Once the aggregated products accumulate in Photosystem II complexes, removal of them by proteases is difficult, and irreversible inhibition of Photosystem II takes place (irreversible photoinhibition). Important is that various aspects of both the reversible and irreversible photoinhibition are highly dependent on the membrane fluidity of the thylakoids. Heat stress-induced inactivation of photosystem II is an irreversible process, which may be also affected by the fluidity of the thylakoid membranes. Here I describe why the membrane fluidity is a key to regulate the avoidance and tolerance of Photosystem II on environmental stresses.
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Khorobrykh AA, Klimov VV. Involvement of molecular oxygen in the donor-side photoinhibition of Mn-depleted photosystem II membranes. PHOTOSYNTHESIS RESEARCH 2015; 126:417-425. [PMID: 25862644 DOI: 10.1007/s11120-015-0135-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 03/26/2015] [Indexed: 06/04/2023]
Abstract
It has been shown by Khorobrykh et al. (Biochemistry (Moscow) 67:683-688, 2002); Yanykin et al. (Biochim Biophys Acta 1797:516-523, 2010); Khorobrykh et al. (Biochemistry 50:10658-10665, 2011) that Mn-depleted photosystem II (PSII) membrane fragments are characterized by an enhanced oxygen photoconsumption on the donor side of PSII which is accompanied with hydroperoxide formation and it was suggested that the events are related to the oxidative photoinhibition of PSII. Experimental confirmation of this suggestion is presented in this work. The degree of photoinhibition was determined by the loss of the capability of exogenous electron donors (Mn(2+) or sodium ascorbate) to the reactivation of electron transport [measured by the light-induced changes of chlorophyll fluorescence yield (∆F)] in Mn-depleted PSII membranes. The transition from anaerobic conditions to aerobic ones significantly activated photoinhibition of Mn-depleted PSII membranes both in the absence and in the presence of exogenous electron acceptor, ferricyanide. The photoinhibition of Mn-depleted PSII membranes was suppressed upon the addition of exogenous electron donors (Mn(2+), diphenylcarbazide, and ferrocyanide). The addition of superoxide dismutase did not affect the photoinhibition of Mn-depleted PSII membranes. It is concluded that the interaction of molecular oxygen (rather than superoxide anion radical formed on the acceptor side of PSII) with the oxidized components of the donor side of PSII reflects the involvement of O2 in the donor-side photoinhibition of Mn-depleted PSII membranes.
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Affiliation(s)
- A A Khorobrykh
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| | - V V Klimov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
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Nama S, Madireddi SK, Devadasu ER, Subramanyam R. High light induced changes in organization, protein profile and function of photosynthetic machinery in Chlamydomonas reinhardtii. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:367-76. [DOI: 10.1016/j.jphotobiol.2015.08.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/26/2015] [Accepted: 08/27/2015] [Indexed: 01/09/2023]
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Pospíšil P, Prasad A. Formation of singlet oxygen and protection against its oxidative damage in Photosystem II under abiotic stress. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 137:39-48. [DOI: 10.1016/j.jphotobiol.2014.04.025] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 04/25/2014] [Accepted: 04/27/2014] [Indexed: 01/10/2023]
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Yamamoto Y, Kai S, Ohnishi A, Tsumura N, Ishikawa T, Hori H, Morita N, Ishikawa Y. Quality control of PSII: behavior of PSII in the highly crowded grana thylakoids under excessive light. PLANT & CELL PHYSIOLOGY 2014; 55:1206-15. [PMID: 24610582 PMCID: PMC4080270 DOI: 10.1093/pcp/pcu043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 02/22/2014] [Indexed: 05/19/2023]
Abstract
The grana thylakoids of higher plant chloroplasts are crowded with PSII and the associated light-harvesting complexes (LHCIIs). They constitute supercomplexes, and often form semi-crystalline arrays in the grana. The crowded condition of the grana may be necessary for efficient trapping of excitation energy by LHCII under weak light, but it might hinder proper movement of LHCII necessary for reversible aggregation of LHCII in the energy-dependent quenching of Chl fluorescence under moderate high light. When the thylakoids are illuminated with extreme high light, the reaction center-binding D1 protein of PSII is photodamaged, and the damaged protein migrates to the grana margins for degradation and subsequent repair. In both moderate and extreme high-light conditions, fluidity of the thylakoid membrane is crucial. In this review, we first provide an overview of photoprotective processes, then discuss changes in membrane fluidity and mobility of the protein complexes in the grana under excessive light, which are closely associated with photoprotection of PSII. We hypothesize that reversible aggregation of LHCII, which is necessary to avoid light stress under moderate high light, and swift turnover of the photodamaged D1 protein under extreme high light are threatened by irreversible protein aggregation induced by reactive oxygen species in photochemical reactions.
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Affiliation(s)
- Yasusi Yamamoto
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
| | - Suguru Kai
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
| | - Atsuki Ohnishi
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
| | - Nodoka Tsumura
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
| | - Tomomi Ishikawa
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
| | - Haruka Hori
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
| | - Noriko Morita
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
| | - Yasuo Ishikawa
- Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530 Japan
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Telfer A. Singlet oxygen production by PSII under light stress: mechanism, detection and the protective role of β-carotene. PLANT & CELL PHYSIOLOGY 2014; 55:1216-23. [PMID: 24566536 PMCID: PMC4080269 DOI: 10.1093/pcp/pcu040] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 02/14/2014] [Indexed: 05/18/2023]
Abstract
In this review, I outline the indirect evidence for the formation of singlet oxygen ((1)O(2)) obtained from experiments with the isolated PSII reaction center complex. I also review the methods we used to measure singlet oxygen directly, including luminescence at 1,270 nm, both steady state and time resolved. Other methods we used were histidine-catalyzed molecular oxygen uptake (enabling (1)O(2) yield measurements), and dye bleaching and difference absorption spectroscopy to identify where quenchers of (1)O(2) can access this toxic species. We also demonstrated the protective behavior of carotenoids bound within Chl-protein complexes which bring about a substantial amount of (1)O(2) quenching within the reaction center complex. Finally, I describe how these techniques have been used and expanded in research on photoinhibition and on the role of (1)O(2) as a signaling molecule in instigating cellular responses to various stress factors. I also discuss the current views on the role of (1)O(2) as a signaling molecule and the distance it might be able to travel within cells.
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Affiliation(s)
- Alison Telfer
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
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Pospíšil P. The Role of Metals in Production and Scavenging of Reactive Oxygen Species in Photosystem II. ACTA ACUST UNITED AC 2014; 55:1224-32. [DOI: 10.1093/pcp/pcu053] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Yoshioka-Nishimura M, Yamamoto Y. Quality control of Photosystem II: the molecular basis for the action of FtsH protease and the dynamics of the thylakoid membranes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 137:100-6. [PMID: 24725639 DOI: 10.1016/j.jphotobiol.2014.02.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/17/2014] [Accepted: 02/17/2014] [Indexed: 01/20/2023]
Abstract
The reaction center-binding D1 protein of Photosystem II is damaged by excessive light, which leads to photoinhibition of Photosystem II. The damaged D1 protein is removed immediately by specific proteases, and a metalloprotease FtsH located in the thylakoid membranes is involved in the proteolytic process. According to recent studies on the distribution and organization of the protein complexes/supercomplexes in the thylakoid membranes, the grana of higher plant chloroplasts are crowded with Photosystem II complexes and light-harvesting complexes. For the repair of the photodamaged D1 protein, the majority of the active hexameric FtsH proteases should be localized in close proximity to the Photosystem II complexes. The unstacking of the grana may increase the area of the grana margin and facilitate easier access of the FtsH proteases to the damaged D1 protein. These results suggest that the structural changes of the thylakoid membranes by light stress increase the mobility of the membrane proteins and support the quality control of Photosystem II.
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Affiliation(s)
- Miho Yoshioka-Nishimura
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
| | - Yasusi Yamamoto
- Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
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Yamamoto Y, Hori H, Kai S, Ishikawa T, Ohnishi A, Tsumura N, Morita N. Quality control of Photosystem II: reversible and irreversible protein aggregation decides the fate of Photosystem II under excessive illumination. FRONTIERS IN PLANT SCIENCE 2013; 4:433. [PMID: 24194743 PMCID: PMC3810940 DOI: 10.3389/fpls.2013.00433] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 10/11/2013] [Indexed: 05/20/2023]
Abstract
In response to excessive light, the thylakoid membranes of higher plant chloroplasts show dynamic changes including the degradation and reassembly of proteins, a change in the distribution of proteins, and large-scale structural changes such as unstacking of the grana. Here, we examined the aggregation of light-harvesting chlorophyll-protein complexes and Photosystem II core subunits of spinach thylakoid membranes under light stress with 77K chlorophyll fluorescence; aggregation of these proteins was found to proceed with increasing light intensity. Measurement of changes in the fluidity of thylakoid membranes with fluorescence polarization of diphenylhexatriene showed that membrane fluidity increased at a light intensity of 500-1,000 μmol photons m(-) (2) s(-) (1), and decreased at very high light intensity (1,500 μmol photons m(-) (2) s(-) (1)). The aggregation of light-harvesting complexes at moderately high light intensity is known to be reversible, while that of Photosystem II core subunits at extremely high light intensity is irreversible. It is likely that the reversibility of protein aggregation is closely related to membrane fluidity: increases in fluidity should stimulate reversible protein aggregation, whereas irreversible protein aggregation might decrease membrane fluidity. When spinach leaves were pre-illuminated with moderately high light intensity, the qE component of non-photochemical quenching and the optimum quantum yield of Photosystem II increased, indicating that Photosystem II/light-harvesting complexes rearranged in the thylakoid membranes to optimize Photosystem II activity. Transmission electron microscopy revealed that the thylakoids underwent partial unstacking under these light stress conditions. Thus, protein aggregation is involved in thylakoid dynamics and regulates photochemical reactions, thereby deciding the fate of Photosystem II.
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Affiliation(s)
- Yasusi Yamamoto
- *Correspondence: Yasusi Yamamoto, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan e-mail:
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