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Milrad Y, Mosebach L, Buchert F. Regulation of Microalgal Photosynthetic Electron Transfer. PLANTS (BASEL, SWITZERLAND) 2024; 13:2103. [PMID: 39124221 PMCID: PMC11314055 DOI: 10.3390/plants13152103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 07/24/2024] [Accepted: 07/26/2024] [Indexed: 08/12/2024]
Abstract
The global ecosystem relies on the metabolism of photosynthetic organisms, featuring the ability to harness light as an energy source. The most successful type of photosynthesis utilizes a virtually inexhaustible electron pool from water, but the driver of this oxidation, sunlight, varies on time and intensity scales of several orders of magnitude. Such rapid and steep changes in energy availability are potentially devastating for biological systems. To enable a safe and efficient light-harnessing process, photosynthetic organisms tune their light capturing, the redox connections between core complexes and auxiliary electron mediators, ion passages across the membrane, and functional coupling of energy transducing organelles. Here, microalgal species are the most diverse group, featuring both unique environmental adjustment strategies and ubiquitous protective mechanisms. In this review, we explore a selection of regulatory processes of the microalgal photosynthetic apparatus supporting smooth electron flow in variable environments.
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Affiliation(s)
- Yuval Milrad
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Laura Mosebach
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
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2
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Lyu H, Zuo YS. Dynamic modulation of transthylakoid electric potential by chloroplast ATP synthases. Biochimie 2024; 221:27-37. [PMID: 38224902 DOI: 10.1016/j.biochi.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/07/2023] [Accepted: 01/12/2024] [Indexed: 01/17/2024]
Abstract
The light-induced transthylakoid membrane potential (ΔΨm) can function as a driving force to help catalyzing the formation of ATP molecules, proving a tight connection between ΔΨm and the ATP synthase. Naturally, a question can be raised on the effects of altered functioning of ATP synthases on regulating ΔΨm, which is attractive in the area of photosynthetic research. Lots of findings, when making efforts of solving this difficulty, can offer an in-depth understanding into the mechanism behind. However, the functional network on modulating ΔΨm is highly interdependent. It is difficult to comprehend the consequences of altered activity of ATP synthases on adjusting ΔΨm because parameters that have influences on ΔΨm would themselves be affected by ΔΨm. In this work, a computer model was applied to check the kinetic changes in polarization/depolarization across the thylakoid membrane (TM) regulated by the modified action of ATP synthases. The computing data revealed that under the extreme condition by numerically "switching off" the action of the ATP synthase, the complete inactivation of ATP synthase would markedly impede proton translocation at the cytb6f complex. Concurrently, the KEA3 (CLCe) porter, actively pumping protons into the stroma, further contributes to achieving a sustained low level of ΔΨm. Besides, the quantitative consequences on every particular component of ΔΨm adjusted by the modified functioning of ATP synthases were also explored. By employing the model, we bring evidence from the theoretical perspective that the ATP synthase is a key factor in forming a transmembrane proton loop thereby maintaining a propriate steady-state ΔΨm to meet variable environmental conditions.
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Affiliation(s)
- Hui Lyu
- School of Biological Science and Agriculture, Qiannan Normal University for Nationalities, Duyun, China.
| | - Yong-Song Zuo
- School of Biological Science and Agriculture, Qiannan Normal University for Nationalities, Duyun, China
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3
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Heuermann MC, Meyer RC, Knoch D, Tschiersch H, Altmann T. Strong prevalence of light regime-specific QTL in Arabidopsis detected using automated high-throughput phenotyping in fluctuating or constant light. PHYSIOLOGIA PLANTARUM 2024; 176:e14255. [PMID: 38528708 DOI: 10.1111/ppl.14255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/27/2024] [Accepted: 03/01/2024] [Indexed: 03/27/2024]
Abstract
Plants have evolved and adapted under dynamic environmental conditions, particularly to fluctuating light, but plant research has often focused on constant growth conditions. To quantitatively asses the adaptation to fluctuating light, a panel of 384 natural Arabidopsis thaliana accessions was analyzed in two parallel independent experiments under fluctuating and constant light conditions in an automated high-throughput phenotyping system upgraded with supplemental LEDs. While the integrated daily photosynthetically active radiation was the same under both light regimes, plants in fluctuating light conditions accumulated significantly less biomass and had lower leaf area during their measured vegetative growth than plants in constant light. A total of 282 image-derived architectural and/or color-related traits at six common time points, and 77 photosynthesis-related traits from one common time point were used to assess their associations with genome-wide natural variation for both light regimes. Out of the 3000 significant marker-trait associations (MTAs) detected, only 183 (6.1%) were common for fluctuating and constant light conditions. The prevalence of light regime-specific QTL indicates a complex adaptation. Genes in linkage disequilibrium with fluctuating light-specific MTAs with an adjusted repeatability value >0.5 were filtered for gene ontology terms containing "photo" or "light", yielding 15 selected candidates. The candidate genes are involved in photoprotection, PSII maintenance and repair, maintenance of linear electron flow, photorespiration, phytochrome signaling, and cell wall expansion, providing a promising starting point for further investigations into the response of Arabidopsis thaliana to fluctuating light conditions.
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Affiliation(s)
- Marc C Heuermann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland OT Gatersleben, Germany
| | - Rhonda C Meyer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland OT Gatersleben, Germany
| | - Dominic Knoch
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland OT Gatersleben, Germany
| | - Henning Tschiersch
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland OT Gatersleben, Germany
| | - Thomas Altmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland OT Gatersleben, Germany
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4
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Yang QY, Wang XQ, Yang YJ, Huang W. Fluctuating light induces a significant photoinhibition of photosystem I in maize. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 207:108426. [PMID: 38340689 DOI: 10.1016/j.plaphy.2024.108426] [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: 10/31/2023] [Revised: 01/19/2024] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
In nature, light intensity usually fluctuates and a sudden shade-sun transition can induce photodamage to photosystem I (PSI) in many angiosperms. Photosynthetic regulation in fluctuating light (FL) has been studied extensively in C3 plants; however, little is known about how C4 plants cope FL to prevent PSI photoinhibition. We here compared photosynthetic responses to FL between maize (Zea mays, C4) and tomato (Solanum lycopersicum, C3) grown under full sunlight. Maize leaves had significantly higher cyclic electron flow (CEF) activity and lower photorespiration activity than tomato. Upon a sudden shade-sun transition, maize showed a significant stronger transient PSI over-reduction than tomato, resulting in a significant greater PSI photoinhibition in maize after FL treatment. During the first seconds upon shade-sun transition, CEF was stimulated in maize at a much higher extent than tomato, favoring the rapid formation of trans-thylakoid proton gradient (ΔpH), which was helped by a transient down-regulation of chloroplast ATP synthase activity. Therefore, modulation of ΔpH by regulation of CEF and chloroplast ATP synthase adjusted PSI redox state at donor side, which partially compensated for the deficiency of photorespiration. We propose that C4 plants use different photosynthetic strategies for coping with FL as compared with C3 plants.
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Affiliation(s)
- Qiu-Yan Yang
- School of Life Sciences, Shannxi Normal University, Xi'an, 710119, China; Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Xiao-Qian Wang
- School of Life Sciences, Shannxi Normal University, Xi'an, 710119, China
| | - Ying-Jie Yang
- Flower Research Institute of Yunnan Academy of Agricultural Sciences, Kunming, 650205, China.
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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Integrated Transcriptome and Metabolome Analysis Reveals Phenylpropanoid Biosynthesis and Phytohormone Signaling Contribute to " Candidatus Liberibacter asiaticus" Accumulation in Citrus Fruit Piths (Fluffy Albedo). Int J Mol Sci 2022; 23:ijms232415648. [PMID: 36555287 PMCID: PMC9779719 DOI: 10.3390/ijms232415648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
"Candidatus Liberibacter asiaticus" (CLas) is a phloem-restricted α-proteobacterium that is associated with citrus huanglongbing (HLB), which is the most destructive disease that affects all varieties of citrus. Although midrib is usually used as a material for CLas detection, we recently found that the bacterium was enriched in fruits, especially in the fruit pith. However, no study has revealed the molecular basis of these two parts in responding to CLas infection. Therefore, we performed transcriptome and UHPLC-MS-based targeted and untargeted metabolomics analyses in order to organize the essential genes and metabolites that are involved. Transcriptome and metabolome characterized 4834 differentially expressed genes (DEGs) and 383 differentially accumulated metabolites (DAMs) between the two materials, wherein 179 DEGs and 44 DAMs were affected by HLB in both of the tissues, involving the pathways of phenylpropanoid biosynthesis, phytohormone signaling transduction, starch and sucrose metabolism, and photosynthesis. Notably, we discovered that the gene expression that is related to beta-glucosidase and endoglucanase was up-regulated in fruits. In addition, defense-related gene expression and metabolite accumulation were significantly down-regulated in infected fruits. Taken together, the decreased amount of jasmonic acid, coupled with the reduced accumulation of phenylpropanoid and the increased proliferation of indole-3-acetic acid, salicylic acid, and abscisic acid, compared to leaf midribs, may contribute largely to the enrichment of CLas in fruit piths, resulting in disorders of photosynthesis and starch and sucrose metabolism.
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Regulation of Chloroplast ATP Synthase Modulates Photoprotection in the CAM Plant Vanilla planifolia. Cells 2022; 11:cells11101647. [PMID: 35626684 PMCID: PMC9139848 DOI: 10.3390/cells11101647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 11/27/2022] Open
Abstract
Generally, regulation of cyclic electron flow (CEF) and chloroplast ATP synthase play key roles in photoprotection for photosystems I and II (PSI and PSII) in C3 and C4 plants, especially when CO2 assimilation is restricted. However, how CAM plants protect PSI and PSII when CO2 assimilation is restricted is largely known. In the present study, we measured PSI, PSII, and electrochromic shift signals in the CAM plant Vanilla planifolia. The quantum yields of PSI and PSII photochemistry largely decreased in the afternoon compared to in the morning, indicating that CO2 assimilation was strongly restricted in the afternoon. Meanwhile, non-photochemical quenching (NPQ) in PSII and the donor side limitation of PSI (Y(ND)) significantly increased to protect PSI and PSII. Under such conditions, proton gradient (∆pH) across the thylakoid membranes largely increased and CEF was slightly stimulated, indicating that the increased ∆pH was not caused by the regulation of CEF. In contrast, the activity of chloroplast ATP synthase (gH+) largely decreased in the afternoon. At a given proton flux, the decreasing gH+ increased ∆pH and thus contributed to the enhancement of NPQ and Y(ND). Therefore, in the CAM plant V. planifolia, the ∆pH-dependent photoprotective mechanism is mainly regulated by the regulation of gH+ rather than CEF when CO2 assimilation is restricted.
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Differential response of physiology and metabolic response to drought stress in different sweetpotato cultivars. PLoS One 2022; 17:e0264847. [PMID: 35271628 PMCID: PMC8912141 DOI: 10.1371/journal.pone.0264847] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 02/17/2022] [Indexed: 11/19/2022] Open
Abstract
Sweetpotato (Ipomoea batatas [L.] Lam) is a widely cultivated food crop with generally good adaptability. However, drought stress can cause a significant decline in yield. To reveal the response mechanism of sweetpotato to drought stress, an integrated physiological, proteomic and metabolomic investigation was conducted in leaves of two sweetpotato varieties with differing responses to drought stress, drought-resistant Wanzishu56 (WZ56) and a more sensitive variety, Ningzishu2(NZ2). Physiological analysis showed that the variety with better drought tolerance had superior performance in water retention capacity and photosynthetic efficiency under drought stress. A total of 1140 proteins were identified within the two varieties. Among them, 192 differentially expressed proteins were detected under drought conditions, including 97 that were up-regulated. Functional analysis showed that these up-regulated proteins were primarily involved in photosynthesis, reactive oxygen species metabolism, organonitrogen compound metabolism, and precursor metabolite catabolism and energy generation. All differentially expressed proteins in WZ56 that were involved in photosynthetic and glutathione metabolic processes were up-regulated. Enzyme activity assays were carried out to validate the proteomics data. Moreover, 75 metabolites were found to have a higher expression level in WZ56 than NZ2 under drought stress. The higher concentration of carbohydrates, amino acids, flavonoids and organic acids found in drought-stressed leaves of WZ56 suggested that these metabolites may improve the drought resistance of sweetpotato. This study uncovered specific-proteins and metabolites associated with drought resistance, providing new insights into the molecular mechanisms of drought tolerance in sweetpotato.
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Rodriguez-Heredia M, Saccon F, Wilson S, Finazzi G, Ruban AV, Hanke GT. Protection of photosystem I during sudden light stress depends on ferredoxin:NADP(H) reductase abundance and interactions. PLANT PHYSIOLOGY 2022; 188:1028-1042. [PMID: 35060611 PMCID: PMC8825262 DOI: 10.1093/plphys/kiab550] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/29/2021] [Indexed: 06/14/2023]
Abstract
Plant tolerance to high light and oxidative stress is increased by overexpression of the photosynthetic enzyme Ferredoxin:NADP(H) reductase (FNR), but the specific mechanism of FNR-mediated protection remains enigmatic. It has also been reported that the localization of this enzyme within the chloroplast is related to its role in stress tolerance. Here, we dissected the impact of FNR content and location on photoinactivation of photosystem I (PSI) and photosystem II (PSII) during high light stress of Arabidopsis (Arabidopsis thaliana). The reaction center of PSII is efficiently turned over during light stress, while damage to PSI takes much longer to repair. Our results indicate a PSI sepcific effect, where efficient oxidation of the PSI primary donor (P700) upon transition from darkness to light, depends on FNR recruitment to the thylakoid membrane tether proteins: thylakoid rhodanase-like protein (TROL) and translocon at the inner envelope of chloroplasts 62 (Tic62). When these interactions were disrupted, PSI photoinactivation occurred. In contrast, there was a moderate delay in the onset of PSII damage. Based on measurements of ΔpH formation and cyclic electron flow, we propose that FNR location influences the speed at which photosynthetic control is induced, resulting in specific impact on PSI damage. Membrane tethering of FNR therefore plays a role in alleviating high light stress, by regulating electron distribution during short-term responses to light.
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Affiliation(s)
| | - Francesco Saccon
- Department of Biochemistry, Queen Mary University of London, London E1 4NS, UK
| | - Sam Wilson
- Department of Biochemistry, Queen Mary University of London, London E1 4NS, UK
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Université Grenoble Alpes, Institut National de Recherche Agronomique (INRA), Institut de Recherche en Sciences et Technologies pour le Vivant (iRTSV), CEA Grenoble, F-38054 Grenoble cedex 9, France
| | - Alexander V Ruban
- Department of Biochemistry, Queen Mary University of London, London E1 4NS, UK
| | - Guy T Hanke
- Department of Biochemistry, Queen Mary University of London, London E1 4NS, UK
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Different Strategies for Photosynthetic Regulation under Fluctuating Light in Two Sympatric Paphiopedilum Species. Cells 2021; 10:cells10061451. [PMID: 34200524 PMCID: PMC8229141 DOI: 10.3390/cells10061451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/30/2021] [Accepted: 06/02/2021] [Indexed: 01/10/2023] Open
Abstract
Fluctuating light can cause selective photoinhibition of photosystem I (PSI) in angiosperms. Cyclic electron flow (CEF) around PSI and electron flux from water via the electron transport chain to oxygen (the water-water cycle) play important roles in coping with fluctuating light in angiosperms. However, it is unclear whether plant species in the same genus employ the same strategy to cope with fluctuating light. To answer this question, we measured P700 redox kinetics and chlorophyll fluorescence under fluctuating light in two Paphiopedilum (P.) Pftzer (Orchidaceae) species, P. dianthum and P. micranthum. After transition from dark to high light, P. dianthum displayed a rapid re-oxidation of P700, while P. micranthum displayed an over-reduction of P700. Furthermore, the rapid re-oxidation of P700 in P. dianthum was not observed when measured under anaerobic conditions. These results indicated that photo-reduction of O2 mediated by the water-water cycle was functional in P. dianthum but not in P. micranthum. Within the first few seconds after an abrupt transition from low to high light, PSI was highly oxidized in P. dianthum but was highly reduced in P. micranthum, indicating that the different responses of PSI to fluctuating light between P. micranthum and P. dianthum was attributed to the water-water cycle. In P. micranthum, the lack of the water-water cycle was partially compensated for by an enhancement of CEF. Taken together, P. dianthum and P. micranthum employed different strategies to cope with the abrupt change of light intensity, indicating the diversity of strategies for photosynthetic acclimation to fluctuating light in these two closely related orchid species.
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Tan SL, Yang YJ, Huang W. Moderate heat stress accelerates photoinhibition of photosystem I under fluctuating light in tobacco young leaves. PHOTOSYNTHESIS RESEARCH 2020; 144:373-382. [PMID: 32333230 DOI: 10.1007/s11120-020-00754-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 04/19/2020] [Indexed: 06/11/2023]
Abstract
Moderate heat stress and fluctuating light are typical conditions in summer in tropical and subtropical regions. This type of stress can cause photodamage to photosystems I and II (PSI and PSII). However, photosynthetic responses to the combination of heat and fluctuating light in young leaves are little known. In this study, we investigated chlorophyll fluorescence and P700 redox state under fluctuating light at 25 °C and 42 °C in young leaves of tobacco. Our results indicated that fluctuating light caused selective photodamage to PSI in the young leaves at 25 °C and 42 °C. Furthermore, the moderate heat stress significantly accelerated photoinhibition of PSI under fluctuating light. Within the first 10 s after transition from low to high light, cyclic electron flow (CEF) around PSI was highly stimulated at 25 °C but was slightly activated at 42 °C. Such depression of CEF activation at moderate heat stress were unable to maintain energy balance under high light. As a result, electron flow from PSI to NADP+ was restricted, leading to the over-reduction of PSI electron carriers. These results indicated that moderate heat stress altered the CEF performance under fluctuating light and thus accelerated PSI photoinhibition in tobacco young leaves.
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Affiliation(s)
- Shun-Ling Tan
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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Yang YJ, Zhang SB, Wang JH, Huang W. The decline in photosynthetic rate upon transfer from high to low light is linked to the slow kinetics of chloroplast ATP synthase in Bletilla striata. PHOTOSYNTHESIS RESEARCH 2020; 144:13-21. [PMID: 32166520 DOI: 10.1007/s11120-020-00725-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 02/12/2020] [Indexed: 06/10/2023]
Abstract
Upon a sudden transition from high to low light, the rate of CO2 assimilation (AN) in some plants first decreases to a low level before gradually becoming stable. However, the underlying mechanisms remain controversial. The activity of chloroplast ATP synthase (gH+) is usually depressed under high light when compared with low light. Therefore, we hypothesize that upon a sudden transfer from high to low light, the relatively low gH+ restricts ATP synthesis and thus causes a reduction in AN. To test this hypothesis, we measured gas exchange, chlorophyll fluorescence, P700 redox state, and electrochromic shift signals in Bletilla striata (Orchidaceae). After the transition from saturating to lower irradiance, AN and ETRII decreased first to a low level and then gradually increased to a stable value. Within the first seconds after transfer from high to low light, gH+ was maintained at low levels. During further exposure to low light, gH+ gradually increased to a stable value. Interestingly, a tight positive relationship was found between gH+ and ETRII. These results suggested that upon a sudden transition from high to low light, AN was restricted by gH+ at the step of ATP synthesis. Taken together, we propose that the decline in AN upon sudden transfer from high to low light is linked to the slow kinetics of chloroplast ATP synthase.
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Affiliation(s)
- Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Ji-Hua Wang
- Yunnan Academy of Agricultural Sciences, Kunming, 650205, Yunnan, China.
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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12
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Lu J, Yin Z, Lu T, Yang X, Wang F, Qi M, Li T, Liu Y. Cyclic electron flow modulate the linear electron flow and reactive oxygen species in tomato leaves under high temperature. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 292:110387. [PMID: 32005392 DOI: 10.1016/j.plantsci.2019.110387] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/16/2019] [Accepted: 12/20/2019] [Indexed: 05/02/2023]
Abstract
The cyclic electron flow (CEF) around photosystem I (PSI) plays a crucial role in photosynthesis and also functions in plant tolerance of abiotic environmental stress. However, the role of PGR5/PGRL1- and NDH-dependent CEF in tomato under hightemperature (HT) is poorly understood. Here, we assessed the photoprotective effect of these pathways in tomato leaves under HT by using antimycin A (AA) and rotenone (R), which are chemical inhibitors of PGR5/PGRL1- and NDH-dependent CEF, respectively. The results showed that AA treatment caused significantly greater inhibition of CEF under HT compared to R treatment. Moreover, AA treatment caused a greater decrease in maximal photochemistry efficiency (Fv/Fm) and increased damage to the donor and acceptor side of photosystem II (PSII); however, the limitation of the acceptor side in PSI [Y(NA)] was significantly increased. In addition, thylakoid membrane integrity was compromised and reactive oxygen species, proton gradient (ΔpH), antioxidant enzyme activity, and the expression of photosystem core subunit genes were significantly decreased under AA treatment. These findings indicate that PGR5/PGRL1-dependent CEF protects PSII and PSI from photooxidative damage through the formation of ΔpH while maintaining thylakoid membrane integrity and normal gene expression levels of core photosystem components. This study demonstrates that PGR5/PGRL1-dependent CEF plays a major role in HT response in tomato.
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Affiliation(s)
- Jiazhi Lu
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang, 110866, China; Collaborative Innovation Center of Protected Vegetable Surrounds Bohai Gulf Region, Shenyang, 110866, China
| | - Zepeng Yin
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang, 110866, China; Collaborative Innovation Center of Protected Vegetable Surrounds Bohai Gulf Region, Shenyang, 110866, China
| | - Tao Lu
- Key Laboratory of Horticultural Crops Genetic Improvement (Ministry of Agriculture), Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xiaolong Yang
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang, 110866, China; Collaborative Innovation Center of Protected Vegetable Surrounds Bohai Gulf Region, Shenyang, 110866, China
| | - Feng Wang
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang, 110866, China; Collaborative Innovation Center of Protected Vegetable Surrounds Bohai Gulf Region, Shenyang, 110866, China
| | - Mingfang Qi
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang, 110866, China; Collaborative Innovation Center of Protected Vegetable Surrounds Bohai Gulf Region, Shenyang, 110866, China
| | - Tianlai Li
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang, 110866, China; Collaborative Innovation Center of Protected Vegetable Surrounds Bohai Gulf Region, Shenyang, 110866, China
| | - Yufeng Liu
- College of Horticulture, Shenyang Agricultural University, Shenyang, 110866, China; Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang, 110866, China; Collaborative Innovation Center of Protected Vegetable Surrounds Bohai Gulf Region, Shenyang, 110866, China.
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Sun H, Zhang SB, Liu T, Huang W. Decreased photosystem II activity facilitates acclimation to fluctuating light in the understory plant Paris polyphylla. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1861:148135. [PMID: 31821793 DOI: 10.1016/j.bbabio.2019.148135] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 11/22/2019] [Accepted: 12/04/2019] [Indexed: 01/11/2023]
Abstract
In forests, understory plants are usually exposed to sunflecks on timescales of seconds or minutes. However, it is unclear how understory plants acclimate to fluctuating light. In this study, we compared chlorophyll fluorescence, PSI redox state and the electrochromic shift signal under fluctuating light between an understory plant Paris polyphylla (Liliaceae) and a light-demanding plant Bletilla striata (Orchidaceae). Within the first seconds after transition from low to high light, PSI was highly oxidized in P. polyphylla but was highly reduced in B. striata, although both species could not generate a sufficient trans-thylakoid proton gradient (ΔpH). Furthermore, the outflow of electrons from PSI to O2 was not significant in P. polyphylla, as indicated by the P700 redox kinetics upon dark-to-light transition. Therefore, the different responses of PSI to fluctuating light between P. polyphylla and B. striata could not be explained by ΔpH formation or alternative electron transport. In contrast, upon a sudden transition from low to high light, electron flow from PSII was much lower in P. polyphylla than in B. striata, suggesting that the rapid oxidation of PSI in P. polyphylla was largely attributed to the lower PSII activity. We propose, for the first time, that down-regulation of PSII activity is an important strategy used by some understory angiosperms to cope with sunflecks.
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Affiliation(s)
- Hu Sun
- Kunming Institute of Botany, Chinese Academy of Sciences, 650201 Kunming, China; University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, 650201 Kunming, China
| | - Tao Liu
- National Local Joint Engineering Research Center on Germplasm Utilization and Innovation of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, 650201 Kunming, China.
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, 650201 Kunming, China.
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14
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Yang YJ, Ding XX, Huang W. Stimulation of cyclic electron flow around photosystem I upon a sudden transition from low to high light in two angiosperms Arabidopsis thaliana and Bletilla striata. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 287:110166. [PMID: 31481226 DOI: 10.1016/j.plantsci.2019.110166] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/20/2019] [Accepted: 06/06/2019] [Indexed: 06/10/2023]
Abstract
In angiosperms, cyclic electron flow (CEF) around photosystem I (PSI) is more important for photoprotection under fluctuating light than under constant light. However, the underlying mechanism is not well known. In the present study, we measured the CEF activity, P700 redox state and electrochromic shift signal upon a sudden transition from low to high light in wild-type plants of Arabidopsis thaliana and Bletilla striata (Orchidaceae). Within the first 20 s after transition from low to high light, P700 was highly reduced in both species, which was accompanied with a sufficient proton gradient (ΔpH) across the thylakoid membranes. Meanwhile, the level of CEF activation was elevated. After transition from low to high light for 60 s, the plants generated an optimal ΔpH. Under such condition, PSI was highly oxidized and the level of CEF activation decreased to the steady state. Furthermore, the CEF activation was positively correlated to the P700 reduction ratio. These results indicated that upon a sudden transition from low to high light, the insufficient ΔpH led to the over-reduction of PSI electron carriers, which in turn stimulated the CEF around PSI. This transient stimulation of CEF not only favored the rapid ΔpH formation but also accepted electrons from PSI, thus protecting PSI at donor and acceptor sides. These findings provide new insights into the important role of CEF in regulation of photosynthesis under fluctuating light.
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Affiliation(s)
- Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiao-Xi Ding
- Kunming Forest Resources Administration, Kunming, China
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China.
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15
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Zivcak M, Brestic M, Botyanszka L, Chen YE, Allakhverdiev SI. Phenotyping of isogenic chlorophyll-less bread and durum wheat mutant lines in relation to photoprotection and photosynthetic capacity. PHOTOSYNTHESIS RESEARCH 2019; 139:239-251. [PMID: 30019176 DOI: 10.1007/s11120-018-0559-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
In our experiments, we examined high light responses and photosynthetic capacity of chlorophyll-less isogenic mutant lines of hexaploid bread wheat (Triticum aestivum L.) and tetraploid durum wheat (Triticum durum L.) in comparison to parental lines representing the wild type (WT), in two growth phases and two environments. In young plants, we observed a typical yellow-green phenotype with low chlorophyll content, significantly lower CO2 assimilation rate, elevated chlorophyll a-to-b ratio and insufficient regulation of linear electron transport. In the mutants grown in a moderate light in the growth chamber, a typical "chlorina" phenotype almost disappeared or, at least, was significantly alleviated in later growth stages, including the values of CO2 assimilation and the majority of the measured parameters related to photoprotective responses. On the other hand, in the case of the mutant lines grown in direct sunlight and fluctuating environment, the chlorophyll-less phenotype was evident also in latter growth phases. The chlorophyll-less phenotype was more severe in the durum wheat mutant lines compared to the bread wheat. For example, the durum wheat mutant lines grown outdoors expressed lower flexibility of photoprotective responses, including lower non-photochemical quenching and low rate of cyclic electron flow compared to WT or bread wheat mutants. Based on the analyses, we have identified a set of parameters providing information on the specific photosynthetic traits typical for the chlorophyll-less phenotype. Thus, the proposed way of phenotyping may serve for efficient selection of mutant genotypes for future research or screening activities. As a general result, we observed that the decrease of the chlorophyll content due to mutation was always associated with improper regulation of linear electron transport and a limited ability to prevent over-reduction of PSI acceptor side, regardless of the genotype, environment, and growth stage. This can partly explain why the low chlorophyll mutants were not successful in the evolution of higher plants, despite the photosynthetic capacity observed is high enough and they are fully competitive with wild-type plants in non-fluctuating controlled environment.
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Affiliation(s)
- Marek Zivcak
- Department of Plant Physiology, Slovak University of Agriculture, Nitra, Slovakia
| | - Marian Brestic
- Department of Plant Physiology, Slovak University of Agriculture, Nitra, Slovakia.
| | - Lenka Botyanszka
- Department of Plant Physiology, Slovak University of Agriculture, Nitra, Slovakia
| | - Yang-Er Chen
- College of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Suleyman I Allakhverdiev
- Institute of Plant Physiology Russian Academy of Sciences, Moscow, Russia.
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Russia.
- Department of Plant Physiology, M.V. Lomonosov Moscow State University, Moscow, Russia.
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia.
- Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, Baku, Azerbaijan.
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16
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Yang YJ, Zhang SB, Huang W. Chloroplastic ATP Synthase Alleviates Photoinhibition of Photosystem I in Tobacco Illuminated at Chilling Temperature. FRONTIERS IN PLANT SCIENCE 2018; 9:1648. [PMID: 30487806 PMCID: PMC6246715 DOI: 10.3389/fpls.2018.01648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 10/23/2018] [Indexed: 05/22/2023]
Abstract
Chloroplastic ATP synthase plays a significant role in the regulation of proton motive force (pmf) and proton gradient (ΔpH) across the thylakoid membranes. However, the regulation of chloroplastic ATP synthase at chilling temperature and its role in photoprotection are little known. In our present study, we examined the chlorophyll fluorescence, P700 signal, and electrochromic shift signal at 25°C, and 6°C in tobacco (Nicotiana tabacum L. cv. Samsun). Although photosynthetic electron flow through both PSI and PSII were severely inhibited at 6°C, non-photochemical quenching and P700 oxidation ratio were largely increased. During the photosynthetic induction under high light, the formation of pmf at 6°C was similar to that at 25°C. However, the ΔpH was significantly higher at 6°C, owing to the decreased activity of chloroplastic ATP synthase (g H +). During illumination at 6°C and high light, a high ΔpH made PSI to be highly oxidized, preventing PSI from photoinhibition. These results indicate that the down-regulation of g H + is critical to the buildup of ΔpH at low temperature, adjusting the redox state of PSI, and thus preventing photodamage to PSI. Our findings highlight the importance of chloroplastic ATP synthase in photoprotection at chilling temperature.
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Affiliation(s)
- Ying-Jie Yang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shi-Bao Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Wei Huang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
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