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Penzler JF, Naranjo B, Walz S, Marino G, Kleine T, Leister D. A pgr5 suppressor screen uncovers two distinct suppression mechanisms and links cytochrome b6f complex stability to PGR5. THE PLANT CELL 2024:koae098. [PMID: 38781425 DOI: 10.1093/plcell/koae098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/13/2024] [Indexed: 05/25/2024]
Abstract
PROTON GRADIENT REGULATION5 (PGR5) is thought to promote cyclic electron flow, and its deficiency impairs photosynthetic control and increases photosensitivity of photosystem (PS) I, leading to seedling lethality under fluctuating light (FL). By screening for Arabidopsis (Arabidopsis thaliana) suppressor mutations that rescue the seedling lethality of pgr5 plants under FL, we identified a portfolio of mutations in 12 different genes. These mutations affect either PSII function, cytochrome b6f (cyt b6f) assembly, plastocyanin (PC) accumulation, the CHLOROPLAST FRUCTOSE-1,6-BISPHOSPHATASE1 (cFBP1), or its negative regulator ATYPICAL CYS HIS-RICH THIOREDOXIN2 (ACHT2). The characterization of the mutants indicates that the recovery of viability can in most cases be explained by the restoration of PSI donor side limitation, which is caused by reduced electron flow to PSI due to defects in PSII, cyt b6f, or PC. Inactivation of cFBP1 or its negative regulator ACHT2 results in increased levels of the NADH dehydrogenase-like complex. This increased activity may be responsible for suppressing the pgr5 phenotype under FL conditions. Plants that lack both PGR5 and DE-ETIOLATION-INDUCED PROTEIN1 (DEIP1)/NEW TINY ALBINO1 (NTA1), previously thought to be essential for cyt b6f assembly, are viable and accumulate cyt b6f. We suggest that PGR5 can have a negative effect on the cyt b6f complex and that DEIP1/NTA1 can ameliorate this negative effect.
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Affiliation(s)
- Jan-Ferdinand Penzler
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried D-82152, Germany
| | - Belén Naranjo
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried D-82152, Germany
| | - Sabrina Walz
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried D-82152, Germany
| | - Giada Marino
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried D-82152, Germany
| | - Tatjana Kleine
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried D-82152, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried D-82152, Germany
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2
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Taj Z, Bakka K, Challabathula D. Halotolerant PGPB Staphylococcus sciuri ET101 protects photosynthesis through activation of redox dissipation pathways in Lycopersicon esculentum. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 208:108482. [PMID: 38492488 DOI: 10.1016/j.plaphy.2024.108482] [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: 01/24/2024] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/18/2024]
Abstract
Photosynthesis is known to be seriously affected by salt stress. The stress induced membrane damage leads to disrupted photosynthetic components causing imbalance between production and utilization of ATP/NADPH with generation of ROS leading to photoinhibition and photodamage. In the current study, role of halotolerant plant growth promoting bacteria (PGPB) Staphylococcus sciuri ET101 in protection of photosynthesis in tomato plants during salinity stress was evaluated by analysing changes in antioxidant defense and activation of redox dissipation pathways. Inoculation of S. sciuri ET101 significantly enhanced the growth of tomato plants with significantly higher photosynthetic rates (PN) under normal and salinity stress conditions. Further, increased membrane stability, soluble sugar accumulation and significant decrease in malondialdehyde (MDA) content in leaves of ET101 inoculated tomato plants under normal and salinity were observed along with increased expression of antioxidant genes for efficient ROS detoxification and suppression of oxidative damage. Additionally, salinity induced decrease in rate of photosynthesis (PN) due to lowered chloroplastic CO2 concentration (Cc) attributed by low mesophyll conductance (gm) in uninoculated plants was alleviated by ET101 inoculation showing significantly higher carboxylation rate (Vcmax), RuBP generation (Jmax) and increased photorespiration (PR). The genes involved in photorespiratory process, cyclic electron flow (CEF), and alternative oxidase (AOX) pathway of mitochondrial respiration were abundantly expressed in leaves of ET101 inoculated plants indicating their involvement in protecting photosynthesis from salt stress induced photoinhibition. Collectively, our results indicated that S. sciuri ET101 has the potential in protecting photosynthesis of tomato plants under salinity stress through activation of redox dissipation pathways.
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Affiliation(s)
- Zarin Taj
- Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India
| | - Kavya Bakka
- Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India
| | - Dinakar Challabathula
- Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India; Department of Biotechnology, School of Integrative Biology, Central University of Tamil Nadu, Thiruvarur, 610 005, India.
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3
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Tikhonov AN. The cytochrome b 6f complex: plastoquinol oxidation and regulation of electron transport in chloroplasts. PHOTOSYNTHESIS RESEARCH 2024; 159:203-227. [PMID: 37369875 DOI: 10.1007/s11120-023-01034-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
In oxygenic photosynthetic systems, the cytochrome b6f (Cytb6f) complex (plastoquinol:plastocyanin oxidoreductase) is a heart of the hub that provides connectivity between photosystems (PS) II and I. In this review, the structure and function of the Cytb6f complex are briefly outlined, being focused on the mechanisms of a bifurcated (two-electron) oxidation of plastoquinol (PQH2). In plant chloroplasts, under a wide range of experimental conditions (pH and temperature), a diffusion of PQH2 from PSII to the Cytb6f does not limit the intersystem electron transport. The overall rate of PQH2 turnover is determined mainly by the first step of the bifurcated oxidation of PQH2 at the catalytic site Qo, i.e., the reaction of electron transfer from PQH2 to the Fe2S2 cluster of the high-potential Rieske iron-sulfur protein (ISP). This point has been supported by the quantum chemical analysis of PQH2 oxidation within the framework of a model system including the Fe2S2 cluster of the ISP and surrounding amino acids, the low-potential heme b6L, Glu78 and 2,3,5-trimethylbenzoquinol (the tail-less analog of PQH2). Other structure-function relationships and mechanisms of electron transport regulation of oxygenic photosynthesis associated with the Cytb6f complex are briefly outlined: pH-dependent control of the intersystem electron transport and the regulatory balance between the operation of linear and cyclic electron transfer chains.
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Affiliation(s)
- Alexander N Tikhonov
- Department of Biophysics, Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow, Russian Federation, 119991.
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4
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Degen GE, Pastorelli F, Johnson MP. Proton Gradient Regulation 5 is required to avoid photosynthetic oscillations during light transitions. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:947-961. [PMID: 37891008 DOI: 10.1093/jxb/erad428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 10/27/2023] [Indexed: 10/29/2023]
Abstract
The production of ATP and NADPH by the light reactions of photosynthesis and their consumption by the Calvin-Benson-Bassham (CBB) cycle and other downstream metabolic reactions requires careful regulation. Environmental shifts perturb this balance, leading to photo-oxidative stress and losses in CO2 assimilation. Imbalances in the production and consumption of ATP and NADPH manifest themselves as transient instability in the chlorophyll fluorescence, P700, electrochromic shift, and CO2 uptake signals recorded on leaves. These oscillations can be induced in wild-type plants by sudden shifts in CO2 concentration or light intensity; however, mutants exhibiting increased oscillatory behaviour have yet to be reported. This has precluded an understanding of the regulatory mechanisms employed by plants to suppress oscillations. Here we show that the Arabidopsis pgr5 mutant, which is deficient in Proton Gradient Regulation 5 (PGR5)-dependent cyclic electron transfer (CET), exhibits increased oscillatory behaviour. In contrast, mutants lacking the NADH-dehydrogenase-like-dependent CET are largely unaffected. The absence of oscillations in the hope2 mutant which, like pgr5, lacks photosynthetic control and exhibits high ATP synthase conductivity, ruled out loss of these photoprotective mechanisms as causes. Instead, we observed slower formation of the proton motive force and, by inference, ATP synthesis in pgr5 following environmental perturbation, leading to the transient reduction of the electron transfer chain and photosynthetic oscillations. PGR5-dependent CET therefore plays a major role in damping the effect of environmental perturbations on photosynthesis to avoid losses in CO2 fixation.
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Affiliation(s)
- Gustaf E Degen
- Plants, Photosynthesis & Soil, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Federica Pastorelli
- Plants, Photosynthesis & Soil, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Matthew P Johnson
- Plants, Photosynthesis & Soil, School of Biosciences, University of Sheffield, Sheffield, UK
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5
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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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6
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Saroussi S, Redekop P, Karns DAJ, Thomas DC, Wittkopp TM, Posewitz MC, Grossman AR. Restricting electron flow at cytochrome b6f when downstream electron acceptors are severely limited. PLANT PHYSIOLOGY 2023; 192:789-804. [PMID: 36960590 PMCID: PMC10231464 DOI: 10.1093/plphys/kiad185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 06/01/2023]
Abstract
Photosynthetic organisms frequently experience abiotic stress that restricts their growth and development. Under such circumstances, most absorbed solar energy cannot be used for CO2 fixation and can cause the photoproduction of reactive oxygen species (ROS) that can damage the photosynthetic reaction centers of PSI and PSII, resulting in a decline in primary productivity. This work describes a biological "switch" in the green alga Chlamydomonas reinhardtii that reversibly restricts photosynthetic electron transport (PET) at the cytochrome b6f (Cyt b6f) complex when the capacity for accepting electrons downstream of PSI is severely limited. We specifically show this restriction in STARCHLESS6 (sta6) mutant cells, which cannot synthesize starch when they are limited for nitrogen (growth inhibition) and subjected to a dark-to-light transition. This restriction represents a form of photosynthetic control that causes diminished electron flow to PSI and thereby prevents PSI photodamage but does not appear to rely on a ΔpH. Furthermore, when electron flow is restricted, the plastid alternative oxidase (PTOX) becomes active, functioning as an electron valve that dissipates some excitation energy absorbed by PSII and allows the formation of a proton motive force (PMF) that would drive some ATP production (potentially sustaining PSII repair and nonphotochemical quenching [NPQ]). The restriction at the Cyt b6f complex can be gradually relieved with continued illumination. This study provides insights into how PET responds to a marked reduction in availability of downstream electron acceptors and the protective mechanisms involved.
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Affiliation(s)
- Shai Saroussi
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Petra Redekop
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Devin A J Karns
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Dylan C Thomas
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Tyler M Wittkopp
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Matthew C Posewitz
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Arthur R Grossman
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
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7
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Chen Q, Lan Y, Li Q, Kong M, Mi H. Inactivation of photosynthetic cyclic electron transports upregulates photorespiration for compensation of efficient photosynthesis in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2023; 14:1061434. [PMID: 37123850 PMCID: PMC10130413 DOI: 10.3389/fpls.2023.1061434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 03/21/2023] [Indexed: 05/03/2023]
Abstract
Plants have multiple mechanisms to maintain efficient photosynthesis. Photosynthetic cyclic electron transports around photosystem I (CET), which includes the PGR5/PGRL1 and NDH pathways, and photorespiration play a crucial role in photosynthetic efficiency. However, how these two mechanisms are functionally linked is not clear. In this study, we revealed that photorespiration could compensate for the function of CET in efficient photosynthesis by comparison of the growth phenotypes, photosynthetic properties monitored with chlorophyll fluorescence parameters and photosynthetic oxygen evolution in leaves and photorespiratory activity monitored with the difference of photosynthetic oxygen evolution rate under high and low concentration of oxygen conditions between the deleted mutant PGR5 or PGRL1 under NDH defective background (pgr5 crr2 or pgrl1a1b crr2). Both CET mutants pgr5 crr2 and pgrl1a1b crr2 displayed similar suppression effects on photosynthetic capacities of light reaction and growth phenotypes under low light conditions. However, the total CET activity and photosynthetic oxygen evolution of pgr5 crr2 were evidently lower than those of pgrl1a1b crr2, accompanied by the upregulation of photorespiratory activity under low light conditions, resulting in severe suppression of photosynthetic capacities of light reaction and finally photodamaged phenotype under high light or fluctuating light conditions. Based on these findings, we suggest that photorespiration compensates for the loss of CET functions in the regulation of photosynthesis and that coordination of both mechanisms is essential for maintaining the efficient operation of photosynthesis, especially under stressed conditions.
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8
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Wei Y, Chen H, Wang L, Zhao Q, Wang D, Zhang T. Cold acclimation alleviates cold stress-induced PSII inhibition and oxidative damage in tobacco leaves. PLANT SIGNALING & BEHAVIOR 2022; 17:2013638. [PMID: 34964430 PMCID: PMC8920150 DOI: 10.1080/15592324.2021.2013638] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 11/28/2021] [Accepted: 11/29/2021] [Indexed: 05/18/2023]
Abstract
This study aimed to explore how cold acclimation (CA) modulates cold stress in tobacco leaves and reveal the relationship between CA and cold stress resistance, and the mechanism of CA-induced plant resistance to cold stress. This study examined the effects of CA treatment (at 8-10℃ for 2 d) on the cold tolerance of tobacco leaves under 4°C cold stress treatment using seedlings without CA treatment as the control (NA). In both CA and NA leaves, cold stress treatment resulted in a decrease in maximum photochemical efficiency of PSII (Fv/Fm), increase in relative variable fluorescence (VJ) at 2 ms on the standardized OJIP curve, inhibition of PSII activity, and impairment of electron transfer on the acceptor side. Besides increasing the malondialdehyde (MDA) content and electrolyte leakage rate, the cold stress exacerbated the degree of membrane peroxidation. The CA treatment also induced the accumulation of reactive oxygen species (ROS), including superoxide anion (O2·-) and H2O2, and increased the activities of antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbic acid peroxidase (APX). The CA treatment also enhanced the accumulation of soluble sugar (SS) and soluble protein (SP), cyclic electron flow (CEF), and the proportion of regulatory energy dissipation Y(NPQ). Moreover, CA+ cold stress treatment significantly reduced CEF and Y(NPQ) in tobacco leaves than under NA+ cold stress treatment, thus significantly alleviating the degree of PSII photoinhibition. In conclusion, CA treatment significantly alleviated PSII photoinhibition and oxidative damage in tobacco leaves under cold stress treatment. Improvement in cold resistance of tobacco leaves is associated with the induction of antioxidant enzyme activity, accumulation of osmoregulation substances, and initiation of photoprotective mechanisms.
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Affiliation(s)
- Yanli Wei
- Institute of Biological Engineering, Xinxiang Institute of Engineering, Xinxiang, Henan, China
| | - Hongzhi Chen
- Institute of Biological Engineering, Xinxiang Institute of Engineering, Xinxiang, Henan, China
| | - Lu Wang
- Institute of Biological Engineering, Xinxiang Institute of Engineering, Xinxiang, Henan, China
| | - Qin Zhao
- Institute of Biological Engineering, Xinxiang Institute of Engineering, Xinxiang, Henan, China
| | - Di Wang
- Institute of Biological Engineering, Xinxiang Institute of Engineering, Xinxiang, Henan, China
| | - Tongen Zhang
- Institute of Biological Engineering, Xinxiang Institute of Engineering, Xinxiang, Henan, China
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9
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Penzler JF, Marino G, Reiter B, Kleine T, Naranjo B, Leister D. Commonalities and specialties in photosynthetic functions of PROTON GRADIENT REGULATION5 variants in Arabidopsis. PLANT PHYSIOLOGY 2022; 190:1866-1882. [PMID: 35946785 PMCID: PMC9614465 DOI: 10.1093/plphys/kiac362] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/13/2022] [Indexed: 05/19/2023]
Abstract
The PROTON GRADIENT REGULATION5 (PGR5) protein is required for trans-thylakoid proton gradient formation and acclimation to fluctuating light (FL). PGR5 functionally interacts with two other thylakoid proteins, PGR5-like 1 (PGRL1) and 2 (PGRL2); however, the molecular details of these interactions are largely unknown. In the Arabidopsis (Arabidopsis thaliana) pgr5-1 mutant, the PGR5G130S protein accumulates in only small amounts. In this work, we generated a knockout allele of PGR5 (pgr5-Cas) using CRISPR-Cas9 technology. Like pgr5-1, pgr5-Cas is seedling-lethal under FL, but photosynthesis and particularly cyclic electron flow, as well as chlorophyll content, are less severely affected in both pgr5-Cas and pgrl1ab (which lacks PGRL1 and PGR5) than in pgr5-1. These differences are associated with changes in the levels of 260 proteins, including components of the Calvin-Benson cycle, photosystems II and I, and the NDH complex, in pgr5-1 relative to the wild type (WT), pgr5-Cas, and pgrl1ab. Some of the differences between pgr5-1 and the other mutant lines could be tentatively assigned to second-site mutations in the pgr5-1 line, identified by whole-genome sequencing. However, others, particularly the more pronounced photosynthetic defects and PGRL1 depletion (compared to pgr5-Cas), are clearly due to specific negative effects of the amino-acid substitution in PGR5G130S, as demonstrated by complementation analysis. Moreover, pgr5-1 and pgr5-Cas plants are less tolerant to long-term exposure to high light than pgrl1ab plants. These results imply that, in addition to the previously reported necessity of PGRL1 for optimal PGR5 function, PGR5 is required alongside PGRL1 to avoid harmful effects on plant performance.
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Affiliation(s)
| | | | - Bennet Reiter
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
| | - Tatjana Kleine
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
| | | | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
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Riaz A, Deng F, Chen G, Jiang W, Zheng Q, Riaz B, Mak M, Zeng F, Chen ZH. Molecular Regulation and Evolution of Redox Homeostasis in Photosynthetic Machinery. Antioxidants (Basel) 2022; 11:antiox11112085. [PMID: 36358456 PMCID: PMC9686623 DOI: 10.3390/antiox11112085] [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: 09/12/2022] [Revised: 10/14/2022] [Accepted: 10/20/2022] [Indexed: 01/14/2023] Open
Abstract
The recent advances in plant biology have significantly improved our understanding of reactive oxygen species (ROS) as signaling molecules in the redox regulation of complex cellular processes. In plants, free radicals and non-radicals are prevalent intra- and inter-cellular ROS, catalyzing complex metabolic processes such as photosynthesis. Photosynthesis homeostasis is maintained by thiol-based systems and antioxidative enzymes, which belong to some of the evolutionarily conserved protein families. The molecular and biological functions of redox regulation in photosynthesis are usually to balance the electron transport chain, photosystem II, photosystem I, mesophyll and bundle sheath signaling, and photo-protection regulating plant growth and productivity. Here, we review the recent progress of ROS signaling in photosynthesis. We present a comprehensive comparative bioinformatic analysis of redox regulation in evolutionary distinct photosynthetic cells. Gene expression, phylogenies, sequence alignments, and 3D protein structures in representative algal and plant species revealed conserved key features including functional domains catalyzing oxidation and reduction reactions. We then discuss the antioxidant-related ROS signaling and important pathways for achieving homeostasis of photosynthesis. Finally, we highlight the importance of plant responses to stress cues and genetic manipulation of disturbed redox status for balanced and enhanced photosynthetic efficiency and plant productivity.
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Affiliation(s)
- Adeel Riaz
- Hubei Collaborative Innovation Center for Grain Industry, College of Agriculture, Yangtze University, Jingzhou 414000, China
| | - Fenglin Deng
- Hubei Collaborative Innovation Center for Grain Industry, College of Agriculture, Yangtze University, Jingzhou 414000, China
| | - Guang Chen
- College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Wei Jiang
- Hubei Collaborative Innovation Center for Grain Industry, College of Agriculture, Yangtze University, Jingzhou 414000, China
| | - Qingfeng Zheng
- Hubei Collaborative Innovation Center for Grain Industry, College of Agriculture, Yangtze University, Jingzhou 414000, China
| | - Bisma Riaz
- Department of Biotechnology, University of Okara, Okara, Punjab 56300, Pakistan
| | - Michelle Mak
- School of Science, Western Sydney University, Penrith, NSW 2751, Australia
| | - Fanrong Zeng
- Hubei Collaborative Innovation Center for Grain Industry, College of Agriculture, Yangtze University, Jingzhou 414000, China
- Correspondence: (F.Z.); (Z.-H.C.)
| | - Zhong-Hua Chen
- School of Science, Western Sydney University, Penrith, NSW 2751, Australia
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
- Correspondence: (F.Z.); (Z.-H.C.)
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11
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Sun H, Wang XQ, Zeng ZL, Yang YJ, Huang W. Exogenous melatonin strongly affects dynamic photosynthesis and enhances water-water cycle in tobacco. FRONTIERS IN PLANT SCIENCE 2022; 13:917784. [PMID: 35991431 PMCID: PMC9381976 DOI: 10.3389/fpls.2022.917784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 07/11/2022] [Indexed: 06/09/2023]
Abstract
Melatonin (MT), an important phytohormone synthesized naturally, was recently used to improve plant resistance against abiotic and biotic stresses. However, the effects of exogenous melatonin on photosynthetic performances have not yet been well clarified. We found that spraying of exogenous melatonin (100 μM) to leaves slightly affected the steady state values of CO2 assimilation rate (A N ), stomatal conductance (g s ) and mesophyll conductance (g m ) under high light in tobacco leaves. However, this exogenous melatonin strongly delayed the induction kinetics of g s and g m , leading to the slower induction speed of A N . During photosynthetic induction, A N is mainly limited by biochemistry in the absence of exogenous melatonin, but by CO2 diffusion conductance in the presence of exogenous melatonin. Therefore, exogenous melatonin can aggravate photosynthetic carbon loss during photosynthetic induction and should be used with care for crop plants grown under natural fluctuating light. Within the first 10 min after transition from low to high light, photosynthetic electron transport rates (ETR) for A N and photorespiration were suppressed in the presence of exogenous melatonin. Meanwhile, an important alternative electron sink, namely water-water cycle, was enhanced to dissipate excess light energy. These results indicate that exogenous melatonin upregulates water-water cycle to facilitate photoprotection. Taking together, this study is the first to demonstrate that exogenous melatonin inhibits dynamic photosynthesis and improves photoprotection in higher plants.
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Affiliation(s)
- Hu Sun
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiao-Qian Wang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- School of Life Sciences, Northwest University, Xi’an, China
| | - Zhi-Lan Zeng
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
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12
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Lima-Melo Y, Kılıç M, Aro EM, Gollan PJ. Photosystem I Inhibition, Protection and Signalling: Knowns and Unknowns. FRONTIERS IN PLANT SCIENCE 2021; 12:791124. [PMID: 34925429 PMCID: PMC8671627 DOI: 10.3389/fpls.2021.791124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/11/2021] [Indexed: 05/22/2023]
Abstract
Photosynthesis is the process that harnesses, converts and stores light energy in the form of chemical energy in bonds of organic compounds. Oxygenic photosynthetic organisms (i.e., plants, algae and cyanobacteria) employ an efficient apparatus to split water and transport electrons to high-energy electron acceptors. The photosynthetic system must be finely balanced between energy harvesting and energy utilisation, in order to limit generation of dangerous compounds that can damage the integrity of cells. Insight into how the photosynthetic components are protected, regulated, damaged, and repaired during changing environmental conditions is crucial for improving photosynthetic efficiency in crop species. Photosystem I (PSI) is an integral component of the photosynthetic system located at the juncture between energy-harnessing and energy consumption through metabolism. Although the main site of photoinhibition is the photosystem II (PSII), PSI is also known to be inactivated by photosynthetic energy imbalance, with slower reactivation compared to PSII; however, several outstanding questions remain about the mechanisms of damage and repair, and about the impact of PSI photoinhibition on signalling and metabolism. In this review, we address the knowns and unknowns about PSI activity, inhibition, protection, and repair in plants. We also discuss the role of PSI in retrograde signalling pathways and highlight putative signals triggered by the functional status of the PSI pool.
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Affiliation(s)
- Yugo Lima-Melo
- Post-graduation Programme in Cellular and Molecular Biology (PPGBCM), Department of Botany, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Mehmet Kılıç
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Peter J. Gollan
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
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Diurnal Response of Photosystem I to Fluctuating Light Is Affected by Stomatal Conductance. Cells 2021; 10:cells10113128. [PMID: 34831351 PMCID: PMC8621556 DOI: 10.3390/cells10113128] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 11/17/2022] Open
Abstract
Upon a sudden transition from low to high light, electrons transported from photosystem II (PSII) to PSI should be rapidly consumed by downstream sinks to avoid the over-reduction of PSI. However, the over-reduction of PSI under fluctuating light might be accelerated if primary metabolism is restricted by low stomatal conductance. To test this hypothesis, we measured the effect of diurnal changes in stomatal conductance on photosynthetic regulation under fluctuating light in tomato (Solanum lycopersicum) and common mulberry (Morus alba). Under conditions of high stomatal conductance, we observed PSI over-reduction within the first 10 s after transition from low to high light. Lower stomatal conductance limited the activity of the Calvin–Benson–Bassham cycle and aggravated PSI over-reduction within 10 s after the light transition. We also observed PSI over-reduction after transition from low to high light for 30 s at the low stomatal conductance typical of the late afternoon, indicating that low stomatal conductance extends the period of PSI over-reduction under fluctuating light. Therefore, diurnal changes in stomatal conductance significantly affect the PSI redox state under fluctuating light. Moreover, our analysis revealed an unexpected inhibition of cyclic electron flow by the severe over-reduction of PSI seen at low stomatal conductance. In conclusion, stomatal conductance can have a large effect on thylakoid reactions under fluctuating light.
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14
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Yang YJ, Sun H, Zhang SB, Huang W. Roles of alternative electron flows in response to excess light in Ginkgo biloba. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 312:111030. [PMID: 34620434 DOI: 10.1016/j.plantsci.2021.111030] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
Ginkgo biloba L., the only surviving species of Ginkgoopsida, is a famous relict gymnosperm, it may provide new insight into the evolution of photosynthetic mechanisms. Flavodiiron proteins (FDPs) are conserved in nonflowering plants, but the role of FDPs in gymnosperms has not yet been clarified. In particular, how gymnosperms integrate FDPs and cyclic electron transport (CET) to better adapt to excess light is poorly understood. To elucidate these questions, we measured the P700 signal, chlorophyll fluorescence and electrochromic shift signal under fluctuating and constant light in G. biloba. Within the first seconds after light increased, G. biloba could not build up a sufficient proton gradient (ΔpH). Concomitantly, photo-reduction of O2 mediated by FDPs contributed to the rapid oxidation of P700 and protected PSI under fluctuating light. Therefore, in G. biloba, FDPs mainly protect PSI under fluctuating light at acceptor side. Under constant high light, the oxidation of PSI and the induction of non-photochemical quenching were attributed to the increase in ΔpH formation, which was mainly caused by the increase in CET rather than linear electron transport. Therefore, under constant light, CET finely regulates the PSI redox state and non-photochemical quenching through ΔpH formation, protecting PSI and PSII against excess light. We conclude that, in G. biloba, FDPs are particularly important under fluctuating light while CET is essential under constant high light. The coordination of FDPs and CET fine-tune photosynthetic apparatus under excess light.
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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
| | - Hu Sun
- 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
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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15
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Identification of a Novel Mutation Exacerbated the PSI Photoinhibition in pgr5/ pgrl1 Mutants; Caution for Overestimation of the Phenotypes in Arabidopsis pgr5-1 Mutant. Cells 2021; 10:cells10112884. [PMID: 34831107 PMCID: PMC8616342 DOI: 10.3390/cells10112884] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 12/12/2022] Open
Abstract
PSI photoinhibition is usually avoided through P700 oxidation. Without this protective mechanism, excess light represents a potentially lethal threat to plants. PGR5 is suggested to be a major component of cyclic electron transport around PSI and is important for P700 oxidation in angiosperms. The known Arabidopsis PGR5 deficient mutant, pgr5-1, is incapable of P700 oxidation regulation and has been used in numerous photosynthetic studies. However, here it was revealed that pgr5-1 was a double mutant with exaggerated PSI photoinhibition. pgr5-1 significantly reduced growth compared to the newly isolated PGR5 deficient mutant, pgr5hope1. The introduction of PGR5 into pgr5-1 restored P700 oxidation regulation, but remained a pale-green phenotype, indicating that pgr5-1 had additional mutations. Both pgr5-1 and pgr5hope1 tended to cause PSI photoinhibition by excess light, but pgr5-1 exhibited an enhanced reduction in PSI activity. Introducing AT2G17240, a candidate gene for the second mutation into pgr5-1 restored the pale-green phenotype and partially restored PSI activity. Furthermore, a deficient mutant of PGRL1 complexing with PGR5 significantly reduced PSI activity in the double-deficient mutant with AT2G17240. From these results, we concluded that AT2G17240, named PSI photoprotection 1 (PTP1), played a role in PSI photoprotection, especially in PGR5/PGRL1 deficient mutants.
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Zhang JY, Zhang QH, Shuang SP, Cun Z, Wu HM, Chen JW. The Responses of Light Reaction of Photosynthesis to Dynamic Sunflecks in a Typically Shade-Tolerant Species Panax notoginseng. FRONTIERS IN PLANT SCIENCE 2021; 12:718981. [PMID: 34721452 PMCID: PMC8548386 DOI: 10.3389/fpls.2021.718981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Light is highly heterogeneous in natural conditions, and plants need to evolve a series of strategies to acclimate the dynamic light since it is immobile. The present study aimed to elucidate the response of light reaction of photosynthesis to dynamic sunflecks in a shade-tolerant species Panax notoginseng and to examine the regulatory mechanisms involved in an adaptation to the simulated sunflecks. When P. notoginseng was exposed to the simulated sunflecks, non-photochemical quenching (NPQ) increased rapidly to the maximum value. Moreover, in response to the simulated sunflecks, there was a rapid increase in light-dependent heat dissipation quantum efficiency of photosystem II (PSII) (ΦNPQ), while the maximum quantum yield of PSII under light (F v'/F m') declined. The relatively high fluorescence and constitutive heat dissipation quantum efficiency of PSII (Φf,d) in the plants exposed to transient high light (400, 800, and 1,600 μmol m-2 s-1) was accompanied by the low effective photochemical quantum yield of PSII (ΦPSII) after the dark recovery for 15 min, whereas the plants exposed to transient low light (50 μmol m-2 s-1) has been shown to lead to significant elevation in ΦPSII after darkness recovery. Furthermore, PSII fluorescence and constitutive heat dissipation electron transfer rate (J f,d) was increased with the intensity of the simulated sunflecks, the residual absorbed energy used for the non-net carboxylative processes (J NC) was decreased when the response of electron transfer rate of NPQ pathway of PSII (J NPQ) to transient low light is restricted. In addition, the acceptor-side limitation of PSI [Y(NA)] was increased, while the donor-side limitation of photosystems I (PSI) [Y(ND)] was decreased at transient high light conditions accompanied with active cyclic electron flow (CEF). Meanwhile, when the leaves were exposed to transient high light, the xanthophyll cycle (V cycle) was activated and subsequently, the J NPQ began to increase. The de-epoxidation state [(Z + A)/(V + A + Z)] was strongly correlated with NPQ in response to the sunflecks. In the present study, a rapid engagement of lutein epoxide (Lx) after the low intensity of sunfleck together with the lower NPQ contributed to an elevation in the maximum photochemical quantum efficiency of PSII under the light. The analysis based on the correlation between the CEF and electron flow devoted to Ribulose-1, 5-bisphosphate (RuBP) oxygenation (J O) indicated that at a high light intensity of sunflecks, the electron flow largely devoted to RuBP oxygenation would contribute to the operation of the CEF. Overall, photorespiration plays an important role in regulating the CEF of the shade-tolerant species, such as P. notoginseng in response to transient high light, whereas active Lx cycle together with the decelerated NPQ may be an effective mechanism of elevating the maximum photochemical quantum efficiency of PSII under light exposure to transient low light.
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Affiliation(s)
- Jin-Yan Zhang
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Qiang-Hao Zhang
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Sheng-Pu Shuang
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Zhu Cun
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Hong-Min Wu
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
| | - Jun-Wen Chen
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China
- Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming, China
- National and Local Joint Engineering Research Center on Germplasm Innovation and Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming, China
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Zhang H, Liu X, Zhang H, Wang Y, Li T, Che Y, Wang J, Guo D, Sun G, Li X. Thioredoxin-like protein CDSP32 alleviates Cd-induced photosynthetic inhibition in tobacco leaves by regulating cyclic electron flow and excess energy dissipation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 167:831-839. [PMID: 34530327 DOI: 10.1016/j.plaphy.2021.09.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 09/08/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
Thioredoxin-like protein CDSP32 (Trx CDSP32), a thioredoxin-like (Trx-like) protein located in the chloroplast, can regulate photosynthesis and the redox state of plants under stress. In order to examine the role of Trx CDSP32 in the photosynthetic apparatus of plants exposed to cadmium (Cd), the effects of Trx CDSP32 on photosynthetic function and photoprotection in tobacco leaves under Cd exposure were studied using a proteomics approach with wild-type (WT) and Trx CDSP32 overexpression (OE) tobacco plants. Cd exposure reduced stomatal conductance, blocked PSII photosynthetic electron transport, and inhibited carbon assimilation. Increased water use efficiency (WUE), cyclic electron flow (CEF) of the proton gradient regulation 5 pathway (PGR5-CEF), and regulated energy dissipation [Y(NPQ)] are important mechanisms of Cd adaptation. However, CEF of the NAD(P)H dehydrogenase pathway (NDH-CEF) was inhibited by Cd exposure. Relative to control conditions, the expression levels of violaxanthin de-epoxidase (VDE) and photosystem II 22 kDa protein (PsbS) in OE leaves were significantly increased under Cd exposure, but those in WT leaves did not change significantly. Moreover, the expression of zeaxanthin epoxidase (ZE) under Cd exposure was significantly higher than that in WT leaves. Thus, Trx CDSP32 increased Y(NPQ) and alleviated PSII photoinhibition under Cd exposure. Trx CDSP32 not only increased PGR5-like protein 1A and 1B expression, but also alleviated the down-regulation of NAD(P)H-quinone oxidoreductase subunits induced by Cd exposure. Thus, Trx CDSP32 promotes CEF in Cd-exposed tobacco leaves. Thus, Trx CDSP32 alleviates the Cd-induced photoinhibition in tobacco leaves by regulating two photoprotective mechanisms: CEF and xanthophyll cycle-dependent energy dissipation.
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Affiliation(s)
- Huihui Zhang
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China.
| | - Xiaoqian Liu
- College of Resources and Environment, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Hongbo Zhang
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Yue Wang
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Tong Li
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Yanhui Che
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Jiechen Wang
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Dandan Guo
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China
| | - Guangyu Sun
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China.
| | - Xin Li
- College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China; College of Resources and Environment, Northeast Agricultural University, Harbin, Heilongjiang, China; School of Forestry, State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China.
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18
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Tan SL, Huang X, Li WQ, Zhang SB, Huang W. Elevated CO 2 Concentration Alters Photosynthetic Performances under Fluctuating Light in Arabidopsis thaliana. Cells 2021; 10:cells10092329. [PMID: 34571978 PMCID: PMC8471415 DOI: 10.3390/cells10092329] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 08/20/2021] [Accepted: 08/20/2021] [Indexed: 01/16/2023] Open
Abstract
In view of the current and expected future rise in atmospheric CO2 concentrations, we examined the effect of elevated CO2 on photoinhibition of photosystem I (PSI) under fluctuating light in Arabidopsis thaliana. At 400 ppm CO2, PSI showed a transient over-reduction within the first 30 s after transition from dark to actinic light. Under the same CO2 conditions, PSI was highly reduced after a transition from low to high light for 20 s. However, such PSI over-reduction greatly decreased when measured in 800 ppm CO2, indicating that elevated atmospheric CO2 facilitates the rapid oxidation of PSI under fluctuating light. Furthermore, after fluctuating light treatment, residual PSI activity was significantly higher in 800 ppm CO2 than in 400 ppm CO2, suggesting that elevated atmospheric CO2 mitigates PSI photoinhibition under fluctuating light. We further demonstrate that elevated CO2 does not affect PSI activity under fluctuating light via changes in non-photochemical quenching or cyclic electron transport, but rather from a rapid electron sink driven by CO2 fixation. Therefore, elevated CO2 mitigates PSI photoinhibition under fluctuating light at the acceptor rather than the donor side. Taken together, these observations indicate that elevated atmospheric CO2 can have large effects on thylakoid reactions under fluctuating light.
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Affiliation(s)
- Shun-Ling Tan
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (S.-L.T.); (X.H.); (W.-Q.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xing Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (S.-L.T.); (X.H.); (W.-Q.L.)
| | - Wei-Qi Li
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (S.-L.T.); (X.H.); (W.-Q.L.)
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (S.-L.T.); (X.H.); (W.-Q.L.)
- Correspondence: (S.-B.Z.); (W.H.)
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (S.-L.T.); (X.H.); (W.-Q.L.)
- Correspondence: (S.-B.Z.); (W.H.)
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19
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Dobson Z, Ahad S, Vanlandingham J, Toporik H, Vaughn N, Vaughn M, Williams D, Reppert M, Fromme P, Mazor Y. The structure of photosystem I from a high-light-tolerant cyanobacteria. eLife 2021; 10:e67518. [PMID: 34435952 PMCID: PMC8428864 DOI: 10.7554/elife.67518] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 08/25/2021] [Indexed: 12/22/2022] Open
Abstract
Photosynthetic organisms have adapted to survive a myriad of extreme environments from the earth's deserts to its poles, yet the proteins that carry out the light reactions of photosynthesis are highly conserved from the cyanobacteria to modern day crops. To investigate adaptations of the photosynthetic machinery in cyanobacteria to excessive light stress, we isolated a new strain of cyanobacteria, Cyanobacterium aponinum 0216, from the extreme light environment of the Sonoran Desert. Here we report the biochemical characterization and the 2.7 Å resolution structure of trimeric photosystem I from this high-light-tolerant cyanobacterium. The structure shows a new conformation of the PsaL C-terminus that supports trimer formation of cyanobacterial photosystem I. The spectroscopic analysis of this photosystem I revealed a decrease in far-red absorption, which is attributed to a decrease in the number of long- wavelength chlorophylls. Using these findings, we constructed two chimeric PSIs in Synechocystis sp. PCC 6803 demonstrating how unique structural features in photosynthetic complexes can change spectroscopic properties, allowing organisms to thrive under different environmental stresses.
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Affiliation(s)
- Zachary Dobson
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Safa Ahad
- Department of Chemistry, Purdue UniversityWest LafayetteUnited States
| | - Jackson Vanlandingham
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Hila Toporik
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Natalie Vaughn
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Michael Vaughn
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Dewight Williams
- John M. Cowley Center for High Resolution Electron Microscopy, Arizona State UniversityTempeUnited States
| | - Michael Reppert
- Department of Chemistry, Purdue UniversityWest LafayetteUnited States
| | - Petra Fromme
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
| | - Yuval Mazor
- School of Molecular Sciences, Arizona State UniversityTempeUnited States
- BiodesignCenter for Applied Structural Discovery, Arizona State UniversityTempeUnited States
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20
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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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21
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Gjindali A, Herrmann HA, Schwartz JM, Johnson GN, Calzadilla PI. A Holistic Approach to Study Photosynthetic Acclimation Responses of Plants to Fluctuating Light. FRONTIERS IN PLANT SCIENCE 2021; 12:668512. [PMID: 33936157 PMCID: PMC8079764 DOI: 10.3389/fpls.2021.668512] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/23/2021] [Indexed: 05/10/2023]
Abstract
Plants in natural environments receive light through sunflecks, the duration and distribution of these being highly variable across the day. Consequently, plants need to adjust their photosynthetic processes to avoid photoinhibition and maximize yield. Changes in the composition of the photosynthetic apparatus in response to sustained changes in the environment are referred to as photosynthetic acclimation, a process that involves changes in protein content and composition. Considering this definition, acclimation differs from regulation, which involves processes that alter the activity of individual proteins over short-time periods, without changing the abundance of those proteins. The interconnection and overlapping of the short- and long-term photosynthetic responses, which can occur simultaneously or/and sequentially over time, make the study of long-term acclimation to fluctuating light in plants challenging. In this review we identify short-term responses of plants to fluctuating light that could act as sensors and signals for acclimation responses, with the aim of understanding how plants integrate environmental fluctuations over time and tailor their responses accordingly. Mathematical modeling has the potential to integrate physiological processes over different timescales and to help disentangle short-term regulatory responses from long-term acclimation responses. We review existing mathematical modeling techniques for studying photosynthetic responses to fluctuating light and propose new methods for addressing the topic from a holistic point of view.
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Affiliation(s)
- Armida Gjindali
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Helena A. Herrmann
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
- Division of Evolution & Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Jean-Marc Schwartz
- Division of Evolution & Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Giles N. Johnson
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Pablo I. Calzadilla
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
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22
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Li Y, Zhang Z, Liu W, Ke M, Qu Q, Zhou Z, Lu T, Qian H. Phyllosphere bacterial assemblage is affected by plant genotypes and growth stages. Microbiol Res 2021; 248:126743. [PMID: 33713869 DOI: 10.1016/j.micres.2021.126743] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/16/2020] [Accepted: 03/02/2021] [Indexed: 01/18/2023]
Abstract
The interaction between plants and microorganisms directly affects plant health and sustainable agricultural development. Leaves represent a wide-area habitat populated by a variety of microorganisms, whose impact on host environmental adaptability could influence plant growth and function. The driving factors for phyllosphere microbiota assemblage are the focus of current research. Here, we investigated the effect of growth stage (i.e., bolting, flowering, and maturation) and genotype of Arabidopsis thaliana (wild-type and the two photosynthetic mutants ndf4 and pgr5) on the composition of phyllosphere microbiota. Our results show that species abundance varied significantly between the three genotypes at different growth stages, whereas species richness and evenness varied only for ndf4. The leaf surface shared a core microbiota dominated by Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes in all tested growth stages and genotypes. Phyllosphere specificity varied more with respect to growth stage than to genotype. In summary, both the growth stage and genotype of A. thaliana are crucial in shaping phyllosphere bacterial composition, with the former being a stronger driver. Our findings provide a novel for investigating whether the host properties influence the phyllosphere community and favor healthy development of plants.
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Affiliation(s)
- Yan Li
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Zhenyan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Wanyue Liu
- Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, PR China
| | - Mingjing Ke
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Qian Qu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Zhigao Zhou
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Tao Lu
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, PR China; Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, PR China.
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23
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Ma M, Liu Y, Bai C, Yang Y, Sun Z, Liu X, Zhang S, Han X, Yong JWH. The Physiological Functionality of PGR5/PGRL1-Dependent Cyclic Electron Transport in Sustaining Photosynthesis. FRONTIERS IN PLANT SCIENCE 2021; 12:702196. [PMID: 34305990 PMCID: PMC8294387 DOI: 10.3389/fpls.2021.702196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/07/2021] [Indexed: 05/07/2023]
Abstract
The cyclic electron transport (CET), after the linear electron transport (LET), is another important electron transport pathway during the light reactions of photosynthesis. The proton gradient regulation 5 (PGR5)/PRG5-like photosynthetic phenotype 1 (PGRL1) and the NADH dehydrogenase-like complex pathways are linked to the CET. Recently, the regulation of CET around photosystem I (PSI) has been recognized as crucial for photosynthesis and plant growth. Here, we summarized the main biochemical processes of the PGR5/PGRL1-dependent CET pathway and its physiological significance in protecting the photosystem II and PSI, ATP/NADPH ratio maintenance, and regulating the transitions between LET and CET in order to optimize photosynthesis when encountering unfavorable conditions. A better understanding of the PGR5/PGRL1-mediated CET during photosynthesis might provide novel strategies for improving crop yield in a world facing more extreme weather events with multiple stresses affecting the plants.
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Affiliation(s)
- Mingzhu Ma
- College of Land and Environment, National Key Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Northeast China Plant Nutrition and Fertilization Scientific Observation and Research Center for Ministry of Agriculture and Rural Affairs, Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang Agricultural University, Shenyang, China
| | - Yifei Liu
- College of Land and Environment, National Key Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Northeast China Plant Nutrition and Fertilization Scientific Observation and Research Center for Ministry of Agriculture and Rural Affairs, Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang Agricultural University, Shenyang, China
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA, Australia
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
- School of Agriculture and Environment, The University of Western Australia, Perth, WA, Australia
- *Correspondence: Yifei Liu, ; Xiaori Han,
| | - Chunming Bai
- National Sorghum Improvement Center, Liaoning Academy of Agricultural Sciences, Shenyang, China
| | - Yunhong Yang
- Professional Technology Innovation Center of Magnesium Nutrition, Yingkou Magnesite Chemical Ind Group Co., Ltd., Yingkou, China
| | - Zhiyu Sun
- College of Land and Environment, National Key Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Northeast China Plant Nutrition and Fertilization Scientific Observation and Research Center for Ministry of Agriculture and Rural Affairs, Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang Agricultural University, Shenyang, China
| | - Xinyue Liu
- College of Land and Environment, National Key Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Northeast China Plant Nutrition and Fertilization Scientific Observation and Research Center for Ministry of Agriculture and Rural Affairs, Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang Agricultural University, Shenyang, China
| | - Siwei Zhang
- College of Land and Environment, National Key Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Northeast China Plant Nutrition and Fertilization Scientific Observation and Research Center for Ministry of Agriculture and Rural Affairs, Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang Agricultural University, Shenyang, China
| | - Xiaori Han
- College of Land and Environment, National Key Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Northeast China Plant Nutrition and Fertilization Scientific Observation and Research Center for Ministry of Agriculture and Rural Affairs, Key Laboratory of Protected Horticulture of Education Ministry and Liaoning Province, Shenyang Agricultural University, Shenyang, China
- *Correspondence: Yifei Liu, ; Xiaori Han,
| | - Jean Wan Hong Yong
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
- Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Alnarp, Sweden
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24
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25
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Barbato R, Tadini L, Cannata R, Peracchio C, Jeran N, Alboresi A, Morosinotto T, Bajwa AA, Paakkarinen V, Suorsa M, Aro EM, Pesaresi P. Higher order photoprotection mutants reveal the importance of ΔpH-dependent photosynthesis-control in preventing light induced damage to both photosystem II and photosystem I. Sci Rep 2020; 10:6770. [PMID: 32317747 PMCID: PMC7174426 DOI: 10.1038/s41598-020-62717-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 03/12/2020] [Indexed: 11/27/2022] Open
Abstract
Although light is essential for photosynthesis, when in excess, it may damage the photosynthetic apparatus, leading to a phenomenon known as photoinhibition. Photoinhibition was thought as a light-induced damage to photosystem II; however, it is now clear that even photosystem I may become very vulnerable to light. One main characteristic of light induced damage to photosystem II (PSII) is the increased turnover of the reaction center protein, D1: when rate of degradation exceeds the rate of synthesis, loss of PSII activity is observed. With respect to photosystem I (PSI), an excess of electrons, instead of an excess of light, may be very dangerous. Plants possess a number of mechanisms able to prevent, or limit, such damages by safe thermal dissipation of light energy (non-photochemical quenching, NPQ), slowing-down of electron transfer through the intersystem transport chain (photosynthesis-control, PSC) in co-operation with the Proton Gradient Regulation (PGR) proteins, PGR5 and PGRL1, collectively called as short-term photoprotection mechanisms, and the redistribution of light between photosystems, called state transitions (responsible of fluorescence quenching at PSII, qT), is superimposed to these short term photoprotective mechanisms. In this manuscript we have generated a number of higher order mutants by crossing genotypes carrying defects in each of the short-term photoprotection mechanisms, with the final aim to obtain a direct comparison of their role and efficiency in photoprotection. We found that mutants carrying a defect in the ΔpH-dependent photosynthesis-control are characterized by photoinhibition of both photosystems, irrespectively of whether PSBS-dependent NPQ or state transitions defects were present or not in the same individual, demonstrating the primary role of PSC in photoprotection. Moreover, mutants with a limited capability to develop a strong PSBS-dependent NPQ, were characterized by a high turnover of the D1 protein and high values of Y(NO), which might reflect energy quenching processes occurring within the PSII reaction center.
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Affiliation(s)
- Roberto Barbato
- Department of Sciences and Innovation Technology, University of Eastern Piedmont Amadeo Avogadro, I-15121, Alessandria, Italy.
| | - Luca Tadini
- Department of Biosciences, University of Milan, I-20133, Milan, Italy
| | - Romina Cannata
- Department of Sciences and Innovation Technology, University of Eastern Piedmont Amadeo Avogadro, I-15121, Alessandria, Italy
| | | | - Nicolaj Jeran
- Department of Biosciences, University of Milan, I-20133, Milan, Italy
| | | | | | - Azfar Ali Bajwa
- Molecular Plant Biology, Department of Biochemistry, University of Turku, SF-20520, Turku, Finland
| | - Virpi Paakkarinen
- Molecular Plant Biology, Department of Biochemistry, University of Turku, SF-20520, Turku, Finland
| | - Marjaana Suorsa
- Molecular Plant Biology, Department of Biochemistry, University of Turku, SF-20520, Turku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, SF-20520, Turku, Finland
| | - Paolo Pesaresi
- Department of Biosciences, University of Milan, I-20133, Milan, Italy
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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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27
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Tan SL, Yang YJ, Liu T, Zhang SB, Huang W. Responses of photosystem I compared with photosystem II to combination of heat stress and fluctuating light in tobacco leaves. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 292:110371. [PMID: 32005377 DOI: 10.1016/j.plantsci.2019.110371] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/02/2019] [Accepted: 12/07/2019] [Indexed: 05/02/2023]
Abstract
Moderate heat stress is usually accompanied with fluctuating light in summer. Although either heat stress or fluctuating light can cause photoinhibition of photosystems I and II (PSI and PSII), it is unclear whether moderate heat stress accelerate photoinhibition under fluctuating light. Here, we measured chlorophyll fluorescence, P700 redox state and the electrochromic shift signal under fluctuating light at 25 °C and 42 °C for tobacco leaves. We found that (1) the thylakoid proton conductance was significantly enhanced at 42 °C, leading to a decline in trans-thylakoid proton gradient (ΔpH); (2) this low ΔpH at 42 °C did not decrease donor-side limitation of PSI and thermal energy dissipation in PSII; (3) the activation of cyclic electron flow (CEF) around PSI was elevated at 42 °C; and (4) the moderate heat stress did not accelerate photoinhibition of PSI and PSII under fluctuating light. These results strongly indicate that under moderate heat stress the stimulation of CEF protects PSI under fluctuating light in tobacco leaves.
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Affiliation(s)
- Shun-Ling Tan
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tao Liu
- National Local Joint Engineering Research Center on Germplasm Utilization and Innovation of Chinese Medicinal Materials in Southwest China, Yunnan Agricultural University, Kunming, 650201, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
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28
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Acid treatment combined with high light leads to increased removal efficiency of Ulva prolifera. ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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29
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Wang F, Yan J, Ahammed GJ, Wang X, Bu X, Xiang H, Li Y, Lu J, Liu Y, Qi H, Qi M, Li T. PGR5/PGRL1 and NDH Mediate Far-Red Light-Induced Photoprotection in Response to Chilling Stress in Tomato. FRONTIERS IN PLANT SCIENCE 2020; 11:669. [PMID: 32547581 PMCID: PMC7270563 DOI: 10.3389/fpls.2020.00669] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 04/29/2020] [Indexed: 05/19/2023]
Abstract
Plants experience low ambient temperature and low red to far-red ratios (L-R/FR) of light due to vegetative shading and longer twilight durations in cool seasons. Low temperature induce photoinhibition through inactivation of the photosynthetic apparatus, however, the role of light quality on photoprotection during cold stress remains poorly understood. Here, we report that L-R/FR significantly prevents the overreduction of the entire intersystem electron transfer chain and the limitation of photosystem I (PSI) acceptor side, eventually alleviating the cold-induced photoinhibition. During cold stress, L-R/FR activated cyclic electron flow (CEF), enhanced protonation of PSII subunit S (PsbS) and de-epoxidation state of the xanthophyll cycle, and promoted energy-dependent quenching (qE) component of non-photochemical quenching (NPQ), enzyme activity of Foyer-Halliwell-Asada cycle and D1 proteins accumulation. However, L-R/FR -induced photoprotection pathways were compromised in tomato PROTON GRADIENT REGULATION5 (PGR5) and PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE1A (PGRL1A) co-silenced plants and NADH DEHYDROGENASE-LIKE COMPLEX M (NDHM) -silenced plants during cold stress. Our results demonstrate that both PGR5/PGRL1- and NDH-dependent CEF mediate L-R/FR -induced cold tolerance by enhancing the thermal dissipation and the repair of photodamaged PSII, thereby mitigating the overreduction of electron carriers and the accumulation of reactive oxygen species. The study indicates that there is an anterograde link between photoreception and photoprotection in tomato plants during cold stress.
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Affiliation(s)
- Feng Wang
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang, China
- National and Local Joint Engineering Research Center of Northern Horticultural Facilities Design and Application Technology (Liaoning), Shenyang, China
- *Correspondence: Feng Wang, ;
| | - Jiarong Yan
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
| | - Golam Jalal Ahammed
- College of Forestry, Henan University of Science and Technology, Luoyang, China
| | - Xiujie Wang
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
| | - Xin Bu
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
| | - Hengzuo Xiang
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
| | - Yanbing Li
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
| | - Jiazhi Lu
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
| | - Yufeng Liu
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang, China
- National and Local Joint Engineering Research Center of Northern Horticultural Facilities Design and Application Technology (Liaoning), Shenyang, China
| | - Hongyan Qi
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang, China
- National and Local Joint Engineering Research Center of Northern Horticultural Facilities Design and Application Technology (Liaoning), Shenyang, China
| | - Mingfang Qi
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang, China
- National and Local Joint Engineering Research Center of Northern Horticultural Facilities Design and Application Technology (Liaoning), Shenyang, China
| | - Tianlai Li
- College of Horticulture, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang, China
- National and Local Joint Engineering Research Center of Northern Horticultural Facilities Design and Application Technology (Liaoning), Shenyang, China
- Tianlai Li,
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30
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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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31
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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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32
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Lima-Melo Y, Alencar VTCB, Lobo AKM, Sousa RHV, Tikkanen M, Aro EM, Silveira JAG, Gollan PJ. Photoinhibition of Photosystem I Provides Oxidative Protection During Imbalanced Photosynthetic Electron Transport in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2019; 10:916. [PMID: 31354779 PMCID: PMC6640204 DOI: 10.3389/fpls.2019.00916] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/28/2019] [Indexed: 05/22/2023]
Abstract
Photosynthesis involves the conversion of sunlight energy into stored chemical energy, which is achieved through electron transport along a series of redox reactions. Excess photosynthetic electron transport might be dangerous due to the risk of molecular oxygen reduction, generating reactive oxygen species (ROS) over-accumulation. Avoiding excess ROS production requires the rate of electron transport to be coordinated with the capacity of electron acceptors in the chloroplast stroma. Imbalance between the donor and acceptor sides of photosystem I (PSI) can lead to inactivation, which is called PSI photoinhibition. We used a light-inducible PSI photoinhibition system in Arabidopsis thaliana to resolve the time dynamics of inhibition and to investigate its impact on ROS production and turnover. The oxidation state of the PSI reaction center and rates of CO2 fixation both indicated strong and rapid PSI photoinhibition upon donor side/acceptor side imbalance, while the rate of inhibition eased during prolonged imbalance. PSI photoinhibition was not associated with any major changes in ROS accumulation or antioxidant activity; however, a lower level of lipid oxidation correlated with lower abundance of chloroplast lipoxygenase in PSI-inhibited leaves. The results of this study suggest that rapid activation of PSI photoinhibition under severe photosynthetic imbalance protects the chloroplast from over-reduction and excess ROS formation.
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Affiliation(s)
- Yugo Lima-Melo
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Vicente T. C. B. Alencar
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
| | - Ana K. M. Lobo
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
| | - Rachel H. V. Sousa
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
| | - Mikko Tikkanen
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Joaquim A. G. Silveira
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
| | - Peter J. Gollan
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
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33
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Yang YJ, Zhang SB, Huang W. Photosynthetic regulation under fluctuating light in young and mature leaves of the CAM plant Bryophyllum pinnatum. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:469-477. [PMID: 31029592 DOI: 10.1016/j.bbabio.2019.04.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 11/27/2022]
Abstract
Photosystem I (PSI) is the potential target of photodamage under fluctuating light in angiosperms. However, the response of PSI to fluctuating light in young leaves has not yet been clarified. Furthermore, the photosynthetic regulation under fluctuating light in crassulacean acid metabolism (CAM) plants is little known. In this study, we measured PSI redox state and the electrochromic shift signal in the mature and young leaves of a CAM species Bryophyllum pinnatum. The mature leaves showed stronger capacity for photo-reduction of O2 mediated by the alternative electron flow (probably the water-water cycle) when compared with the young leaves. After an increase in light intensity, both the mature and young leaves showed insufficient proton gradient (ΔpH) across the thylakoid membranes within the first seconds. Meanwhile, PSI was highly oxidized in the mature leaves but was in a more reduced state in the young leaves. Furthermore, young leaves were more susceptible to PSI photoinhibition under fluctuating light. Therefore, in the mature leaves, the alternative electron flow significantly optimized the PSI redox state under fluctuating light at relatively low ΔpH. By comparison, in the young leaves, PSI redox state was largely determined by the buildup of ΔpH. Therefore, the major photoprotective mechanism responsible for safeguarding PSI under fluctuating light can be influenced by leaf developmental stages.
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Affiliation(s)
- Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, PR China.
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, PR China.
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Huang W, Yang YJ, Zhang SB. The role of water-water cycle in regulating the redox state of photosystem I under fluctuating light. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:383-390. [PMID: 30890407 DOI: 10.1016/j.bbabio.2019.03.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/18/2018] [Accepted: 03/14/2019] [Indexed: 10/27/2022]
Abstract
The regulation of photosystem I (PSI) redox state under fluctuating light was investigated for four species using P700 measurement and electrochromic shift analysis. Species included the angiosperms Camellia japonica, Bletilla striata and Arabidopsis thaliana and the fern Cyrtomium fortunei. For the first seconds after transition from low to high light, all species showed relatively low levels of the proton gradient (ΔpH) across the thylakoid membranes. At this moment, PSI was highly oxidized in C. japonica and C. fortunei but was over-reduced in B. striata and A. thaliana. In B. striata and A. thaliana, the redox state of PSI was largely dependent on ΔpH. In contrast, the rapid oxidation of P700 in C. japonica was relatively independent of ΔpH, but was mainly dependent on the outflow of electrons to O2 via the water-water cycle. In the fern C. fortunei, PSI redox state was rapidly regulated by the fast photo-reduction of O2 rather than the ΔpH. These results indicate that mechanisms regulating PSI redox state under fluctuating light differ greatly between species. We propose that the water-water cycle is an important mechanism regulating the PSI redox state in angiosperms.
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Affiliation(s)
- Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.
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Lima-Melo Y, Gollan PJ, Tikkanen M, Silveira JAG, Aro EM. Consequences of photosystem-I damage and repair on photosynthesis and carbon use in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:1061-1072. [PMID: 30488561 DOI: 10.1111/tpj.14177] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 05/26/2023]
Abstract
Natural growth environments commonly include fluctuating conditions that can disrupt the photosynthetic energy balance and induce photoinhibition through inactivation of the photosynthetic apparatus. Photosystem II (PSII) photoinhibition is efficiently reversed by the PSII repair cycle, whereas photoinhibited photosystem I (PSI) recovers much more slowly. In the current study, treatment of the Arabidopsis thaliana mutant proton gradient regulation 5 (pgr5) with excess light was used to compromise PSI functionality in order to investigate the impact of photoinhibition and subsequent recovery on photosynthesis and carbon metabolism. The negative impact of PSI photoinhibition on CO2 fixation was especially deleterious under low irradiance. Impaired starch accumulation after PSI photoinhibition was reflected in reduced respiration in the dark, but this was not attributed to impaired sugar synthesis. Normal chloroplast and mitochondrial metabolisms were shown to recover despite the persistence of substantial PSI photoinhibition for several days. The results of this study indicate that the recovery of PSI function involves the reorganization of the light-harvesting antennae, and suggest a pool of surplus PSI that can be recruited to support photosynthesis under demanding conditions.
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Affiliation(s)
- Yugo Lima-Melo
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP 60440-900, Fortaleza, CE, Brazil
| | - Peter J Gollan
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Mikko Tikkanen
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Joaquim A G Silveira
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, CEP 60440-900, Fortaleza, CE, Brazil
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
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Selão TT, Jebarani J, Ismail NA, Norling B, Nixon PJ. Enhanced Production of D-Lactate in Cyanobacteria by Re-Routing Photosynthetic Cyclic and Pseudo-Cyclic Electron Flow. FRONTIERS IN PLANT SCIENCE 2019; 10:1700. [PMID: 32117327 PMCID: PMC7025493 DOI: 10.3389/fpls.2019.01700] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 12/03/2019] [Indexed: 05/22/2023]
Abstract
Cyanobacteria are promising chassis strains for the photosynthetic production of platform and specialty chemicals from carbon dioxide. Their efficient light harvesting and metabolic flexibility abilities have allowed a wide range of biomolecules, such as the bioplastic polylactate precursor D-lactate, to be produced, though usually at relatively low yields. In order to increase photosynthetic electron flow towards the production of D-lactate, we have generated several strains of the marine cyanobacterium Synechococcus sp. PCC 7002 (Syn7002) with deletions in genes involved in cyclic or pseudo-cyclic electron flow around photosystem I. Using a variant of the Chlamydomonas reinhardtii D-lactate dehydrogenase (LDHSRT, engineered to efficiently utilize NADPH in vivo), we have shown that deletion of either of the two flavodiiron flv homologs (involved in pseudo-cyclic electron transport) or the Syn7002 pgr5 homolog (proposed to be a vital part of the cyclic electron transport pathway) is able to increase D-lactate production in Syn7002 strains expressing LDHSRT and the Escherichia coli LldP (lactate permease), especially at low temperature (25°C) and 0.04% (v/v) CO2, though at elevated temperatures (38°C) and/or high (1%) CO2 concentrations, the effect was less obvious. The Δpgr5 background seemed to be particularly beneficial at 25°C and 0.04% (v/v) CO2, with a nearly 7-fold increase in D-lactate accumulation in comparison to the wild-type background (≈1000 vs ≈150 mg/L) and decreased side effects in comparison to the flv deletion strains. Overall, our results show that manipulation of photosynthetic electron flow is a viable strategy to increase production of platform chemicals in cyanobacteria under ambient conditions.
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Affiliation(s)
- Tiago Toscano Selão
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Jasmin Jebarani
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Nurul Aina Ismail
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Birgitta Norling
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Peter Julian Nixon
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Department of Life Sciences, Imperial College London, London, United Kingdom
- *Correspondence: Peter Julian Nixon,
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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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Huang W, Tikkanen M, Zhang SB. Photoinhibition of photosystem I in Nephrolepis falciformis depends on reactive oxygen species generated in the chloroplast stroma. PHOTOSYNTHESIS RESEARCH 2018; 137:129-140. [PMID: 29357086 DOI: 10.1007/s11120-018-0484-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/17/2018] [Indexed: 05/26/2023]
Abstract
We studied how high light causes photoinhibition of photosystem I (PSI) in the shade-demanding fern Nephrolepis falciformis, in an attempt to understand the mechanism of PSI photoinhibition under natural field conditions. Intact leaves were treated with constant high light and fluctuating light. Detached leaves were treated with constant high light in the presence and absence of methyl viologen (MV). Chlorophyll fluorescence and P700 signal were determined to estimate photoinhibition. PSI was highly oxidized under high light before treatments. N. falciformis showed significantly stronger photoinhibition of PSI and PSII under constant high light than fluctuating light. These results suggest that high levels of P700 oxidation ratio cannot prevent PSI photoinhibition under high light in N. falciformis. Furthermore, photoinhibition of PSI in N. falciformis was largely accelerated in the presence of MV that promotes the production of superoxide anion radicals in the chloroplast stroma by accepting electrons from PSI. From these results, we propose that photoinhibition of PSI in N. falciformis is mainly caused by superoxide radicals generated in the chloroplast stroma, which is different from the mechanism of PSI photoinhibition in Arabidopsis thaliana and spinach. Here, we provide some new insights into the PSI photoinhibition under natural field conditions.
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Affiliation(s)
- Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
| | - Mikko Tikkanen
- Department of Biochemistry, Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China.
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Huang W, Cai YF, Wang JH, Zhang SB. Chloroplastic ATP synthase plays an important role in the regulation of proton motive force in fluctuating light. JOURNAL OF PLANT PHYSIOLOGY 2018; 226:40-47. [PMID: 29698911 DOI: 10.1016/j.jplph.2018.03.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/25/2018] [Accepted: 03/26/2018] [Indexed: 06/08/2023]
Abstract
The proton motive force (pmf) across the thylakoid membranes plays a key role for photosynthesis in fluctuating light. However, the mechanisms underlying the regulation of pmf in fluctuating light are not well known. In this study, we aimed to identify the roles of chloroplastic ATP synthase and cyclic electron flow (CEF) around photosystem I (PSI) in the regulation of the pmf in fluctuating light. To do this, we measured chlorophyll fluorescence, P700 parameters, and the electrochromic shift signal in the fluctuating light alternating between 918 (high light) and 89 (low light) μmol photons m-2 s-1 every 5 min. We found that the activity of chloroplastic ATP synthase (gH+), pmf, CEF activity, non-photochemical quenching (NPQ), and the P700 redox state changed rapidly in fluctuating light. During transition from low to high light, the decreased gH+ and the stimulation of CEF both contributed to the rapid formation of pmf, activating NPQ and optimizing the redox state of P700 in PSI. During the low-light phases, gH+ rapidly increased and the pmf declined sharply, leading to the relaxation of NPQ and down-regulation of photosynthetic control. These findings indicate that in fluctuating light the gH+ and CEF are finely regulated to modulate the pmf formation, avoiding the over-accumulation of reactive intermediates and maximizing energy use efficiency.
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Affiliation(s)
- Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Yan-Fei Cai
- Flower Research Institute of Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, China
| | - Ji-Hua Wang
- Flower Research Institute of Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, China.
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.
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Gollan PJ, Lima-Melo Y, Tiwari A, Tikkanen M, Aro EM. Interaction between photosynthetic electron transport and chloroplast sinks triggers protection and signalling important for plant productivity. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0390. [PMID: 28808104 PMCID: PMC5566885 DOI: 10.1098/rstb.2016.0390] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2017] [Indexed: 11/12/2022] Open
Abstract
The photosynthetic light reactions provide energy that is consumed and stored in electron sinks, the products of photosynthesis. A balance between light reactions and electron consumption in the chloroplast is vital for plants, and is protected by several photosynthetic regulation mechanisms. Photosystem I (PSI) is particularly susceptible to photoinhibition when these factors become unbalanced, which can occur in low temperatures or in high light. In this study we used the pgr5 Arabidopsis mutant that lacks ΔpH-dependent regulation of photosynthetic electron transport as a model to study the consequences of PSI photoinhibition under high light. We found that PSI damage severely inhibits carbon fixation and starch accumulation, and attenuates enzymatic oxylipin synthesis and chloroplast regulation of nuclear gene expression after high light stress. This work shows that modifications to regulation of photosynthetic light reactions, which may be designed to improve yield in crop plants, can negatively impact metabolism and signalling, and thereby threaten plant growth and stress tolerance.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Peter J Gollan
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Yugo Lima-Melo
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Arjun Tiwari
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Mikko Tikkanen
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014 Turku, Finland
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Cherepanov DA, Milanovsky GE, Petrova AA, Tikhonov AN, Semenov AY. Electron Transfer through the Acceptor Side of Photosystem I: Interaction with Exogenous Acceptors and Molecular Oxygen. BIOCHEMISTRY (MOSCOW) 2018; 82:1249-1268. [PMID: 29223152 DOI: 10.1134/s0006297917110037] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This review considers the state-of-the-art on mechanisms and alternative pathways of electron transfer in photosynthetic electron transport chains of chloroplasts and cyanobacteria. The mechanisms of electron transport control between photosystems (PS) I and II and the Calvin-Benson cycle are considered. The redistribution of electron fluxes between the noncyclic, cyclic, and pseudocyclic pathways plays an important role in the regulation of photosynthesis. Mathematical modeling of light-induced electron transport processes is considered. Particular attention is given to the electron transfer reactions on the acceptor side of PS I and to interactions of PS I with exogenous acceptors, including molecular oxygen. A kinetic model of PS I and its interaction with exogenous electron acceptors has been developed. This model is based on experimental kinetics of charge recombination in isolated PS I. Kinetic and thermodynamic parameters of the electron transfer reactions in PS I are scrutinized. The free energies of electron transfer between quinone acceptors A1A/A1B in the symmetric redox cofactor branches of PS I and iron-sulfur clusters FX, FA, and FB have been estimated. The second-order rate constants of electron transfer from PS I to external acceptors have been determined. The data suggest that byproduct formation of superoxide radical in PS I due to the reduction of molecular oxygen in the A1 site (Mehler reaction) can exceed 0.3% of the total electron flux in PS I.
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Affiliation(s)
- D A Cherepanov
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Moscow, 119992, Russia.
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Murakami K, Matsuda R, Fujiwara K. Quantification of excitation energy distribution between photosystems based on a mechanistic model of photosynthetic electron transport. PLANT, CELL & ENVIRONMENT 2018; 41:148-159. [PMID: 28548208 DOI: 10.1111/pce.12986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 04/16/2017] [Accepted: 04/25/2017] [Indexed: 06/07/2023]
Abstract
Absorbed light energy is converted into excitation energy. The excitation energy is distributed to photosystems depending on the wavelength and drives photochemical reactions. A non-destructive, mechanistic and quantitative method for estimating the fraction of the excitation energy distributed to photosystem II (f) was developed. For the f values for two simultaneously provided actinic lights (ALs) with different spectral distributions to be estimated, photochemical yields of the photosystems were measured under the ALs and were then fitted to an electron transport model assuming the balance between the electron transport rates through the photosystems. For the method to be tested using leaves with different properties in terms of the long-term and short-term acclimation (adjustment of photosystem stoichiometry and state transition, respectively), the f values for red and far-red light (R and FR) were estimated in leaves grown (~1 week) under white light without and with supplemental FR and adapted (~10 min) to R without and with supplemental FR. The f values for R were clearly greater than those for FR and those of leaves grown with and adapted to supplemental FR tended to be higher than the controls. These results are consistent with previous studies and therefore support the validity of the proposed method.
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Affiliation(s)
- Keach Murakami
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| | - Ryo Matsuda
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
| | - Kazuhiro Fujiwara
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-8657, Japan
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Abstract
This chapter presents an overview of structural properties of the cytochrome (Cyt) b 6 f complex and its functioning in chloroplasts. The Cyt b 6 f complex stands at the crossroad of photosynthetic electron transport pathways, providing connectivity between Photosystem (PSI) and Photosysten II (PSII) and pumping protons across the membrane into the thylakoid lumen. After a brief review of the chloroplast electron transport chain, the consideration is focused on the structural organization of the Cyt b 6 f complex and its interaction with plastoquinol (PQH2, reduced form of plastoquinone), a mediator of electron transfer from PSII to the Cyt b 6 f complex. The processes of PQH2 oxidation by the Cyt b 6 f complex have been considered within the framework of the Mitchell's Q-cycle. The overall rate of the intersystem electron transport is determined by PQH2 turnover at the quinone-binding site Qo of the Cyt b 6 f complex. The rate of PQH2 oxidation is controlled by the intrathylakoid pHin, which value determines the protonation/deprotonation events in the Qo-center. Two other regulatory mechanisms associated with the Cyt b 6 f complex are briefly overviewed: (i) redistribution of electron fluxes between alternative (linear and cyclic) pathways, and (ii) "state transitions" related to redistribution of solar energy between PSI and PSII.
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Yang YJ, Chang W, Huang W, Zhang SB, Hu H. The effects of chilling-light stress on photosystems I and II in three Paphiopedilum species. BOTANICAL STUDIES 2017; 58:53. [PMID: 29177684 PMCID: PMC5702284 DOI: 10.1186/s40529-017-0208-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 11/15/2017] [Indexed: 05/08/2023]
Abstract
BACKGROUND Low temperatures pose a critical limitation to the physiology and survival of chilling-sensitive plants. One example is the genus Paphiopedilum (Orchidaceae), which is mainly native to tropical and subtropical areas from Asia to the Pacific islands. However, little is known about the physiological mechanism(s) underlying its sensitivity to chilling temperature. We examined how chilling-light stress influences the activities of photosystem I (PSI) and photosystem II (PSII) in three species: P. armeniacum, P. micranthum, and P. purpuratum. All originate from different distribution zones that cover a range of temperatures. RESULTS Photosystem II of three Paphiopedilum species was remarkable sensitivity to chilling stress. After 8 h chilling stress, the maximum quantum yield of PSII of three species of Paphiopedilum was significantly decreased, especially in P. purpuratum. The quantity of efficient PSI complex (P m ) value did not significantly differ after 8 h chilling treatment compared to the original value in three species. The stronger PSII photoinhibition and significantly less capacity for cyclic electron flow (CEF) were observed in P. purpuratum. CONCLUSIONS In conclusion, the three species of Paphiopedilum showed significant PSII photoinhibition when exposed to 4 °C chilling treatment. However, their PSI activities were not susceptible to chilling-light stress during 8 h. The CEF was important for the photoprotection of PSI and PSII in P. armeniacum and P. micranthum under chilling conditions. Our findings suggested that the photosynthetic characteristics of Paphiopedilum were well adapted to their habitat.
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Affiliation(s)
- Ying-Jie Yang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
- Yunnan Key Laboratory for Wild Plant Resources, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049 People’s Republic of China
| | - Wei Chang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
- Yunnan Key Laboratory for Wild Plant Resources, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
| | - Wei Huang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
- Yunnan Key Laboratory for Wild Plant Resources, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
| | - Shi-Bao Zhang
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
- Yunnan Key Laboratory for Wild Plant Resources, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
| | - Hong Hu
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
- Yunnan Key Laboratory for Wild Plant Resources, 132# Lanhei Road, Heilongtan, Kunming, 650201 Yunnan China
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Sello S, Moscatiello R, La Rocca N, Baldan B, Navazio L. A Rapid and Efficient Method to Obtain Photosynthetic Cell Suspension Cultures of Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2017; 8:1444. [PMID: 28868063 PMCID: PMC5563381 DOI: 10.3389/fpls.2017.01444] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 08/03/2017] [Indexed: 05/29/2023]
Abstract
Photosynthetic cell suspension cultures are a useful experimental system to analyze a variety of physiological processes, bypassing the structural complexity of the plant organism in toto. Nevertheless, cell cultures containing functional chloroplasts are quite difficult to obtain, and this process is usually laborious and time-consuming. In this work a novel and rapid method to set up photosynthetic cell suspension cultures from the model plant Arabidopsis thaliana was developed. The direct germination of Arabidopsis seeds on a sucrose-containing agarized culture medium supplemented with 0.25 μg/ml 6-benzylaminopurine and 0.5 μg/ml 2,4-dichlorophenoxyacetic acid caused the straightforward formation of green calli at the level of seedling hypocotyls. The subsequent transfer of these calli in liquid culture medium containing the same concentrations of phytohormones and gradually decreasing sucrose levels allowed for the establishment of chloroplast-containing cell suspension cultures, containing functional chloroplasts, in a much faster way than previously described procedures. Pulse amplitude modulation analyses, measurements of oxygen evolution and electron transport rate, together with confocal and electron microscopy observations, confirmed the photosynthetic efficiency of these cell suspension cultures. The described procedure lends itself as a simple and effective way to obtain a convenient tool for a wide array of structural and functional studies on chloroplasts.
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Affiliation(s)
- Simone Sello
- Department of Biology, University of PadovaPadova, Italy
| | | | | | - Barbara Baldan
- Department of Biology, University of PadovaPadova, Italy
- Botanical Garden, University of PadovaPadova, Italy
| | - Lorella Navazio
- Department of Biology, University of PadovaPadova, Italy
- Botanical Garden, University of PadovaPadova, Italy
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Beckers V, Dersch LM, Lotz K, Melzer G, Bläsing OE, Fuchs R, Ehrhardt T, Wittmann C. In silico metabolic network analysis of Arabidopsis leaves. BMC SYSTEMS BIOLOGY 2016; 10:102. [PMID: 27793154 PMCID: PMC5086045 DOI: 10.1186/s12918-016-0347-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 10/21/2016] [Indexed: 12/23/2022]
Abstract
Background During the last decades, we face an increasing interest in superior plants to supply growing demands for human and animal nutrition and for the developing bio-based economy. Presently, our limited understanding of their metabolism and its regulation hampers the targeted development of desired plant phenotypes. In this regard, systems biology, in particular the integration of metabolic and regulatory networks, is promising to broaden our knowledge and to further explore the biotechnological potential of plants. Results The thale cress Arabidopsis thaliana provides an ideal model to understand plant primary metabolism. To obtain insight into its functional properties, we constructed a large-scale metabolic network of the leaf of A. thaliana. It represented 511 reactions with spatial separation into compartments. Systematic analysis of this network, utilizing elementary flux modes, investigates metabolic capabilities of the plant and predicts relevant properties on the systems level: optimum pathway use for maximum growth and flux re-arrangement in response to environmental perturbation. Our computational model indicates that the A. thaliana leaf operates near its theoretical optimum flux state in the light, however, only in a narrow range of photon usage. The simulations further demonstrate that the natural day-night shift requires substantial re-arrangement of pathway flux between compartments: 89 reactions, involving redox and energy metabolism, substantially change the extent of flux, whereas 19 reactions even invert flux direction. The optimum set of anabolic pathways differs between day and night and is partly shifted between compartments. The integration with experimental transcriptome data pinpoints selected transcriptional changes that mediate the diurnal adaptation of the plant and superimpose the flux response. Conclusions The successful application of predictive modelling in Arabidopsis thaliana can bring systems-biological interpretation of plant systems forward. Using the gained knowledge, metabolic engineering strategies to engage plants as biotechnological factories can be developed. Electronic supplementary material The online version of this article (doi:10.1186/s12918-016-0347-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Veronique Beckers
- Institute for Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany
| | - Lisa Maria Dersch
- Institute for Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany
| | | | - Guido Melzer
- Institute of Biochemical Engineering, Technical University Braunschweig, Braunschweig, Germany
| | | | | | | | - Christoph Wittmann
- Institute for Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany.
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Takagi D, Hashiguchi M, Sejima T, Makino A, Miyake C. Photorespiration provides the chance of cyclic electron flow to operate for the redox-regulation of P700 in photosynthetic electron transport system of sunflower leaves. PHOTOSYNTHESIS RESEARCH 2016; 129:279-90. [PMID: 27116126 DOI: 10.1007/s11120-016-0267-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/18/2016] [Indexed: 05/24/2023]
Abstract
To elucidate the molecular mechanism to oxidize the reaction center chlorophyll, P700, in PSI, we researched the effects of partial pressure of O2 (pO2) on photosynthetic characteristic parameters in sunflower (Helianthus annuus L.) leaves. Under low CO2 conditions, the oxidation of P700 was stimulated; however the decrease in pO2 suppressed its oxidation. Electron fluxes in PSII [Y(II)] and PSI [Y(I)] showed pO2-dependence at low CO2 conditions. H(+)-consumption rate, estimated from Y(II) and CO2-fixation/photorespiration rates (JgH(+)), showed the positive curvature relationship with the dissipation rate of electrochromic shift signal (V H (+) ), which indicates H(+)-efflux rate from lumen to stroma in chloroplasts. Therefore, these electron fluxes contained, besides CO2-fixation/photorespiration-dependent electron fluxes, non-H(+)-consumption electron fluxes including Mehler-ascorbate peroxidase (MAP)-pathway. Y(I) that was larger than Y(II) surely implies the functioning of cyclic electron flow (CEF). Both MAP-pathway and CEF were suppressed at lower pO2, with plastoquinone-pool reduced. That is, photorespiration prepares the redox-poise of photosynthetic electron transport system for CEF activity as an electron sink. Excess Y(II), [ΔY(II)] giving the curvature relationship with V H (+) , and excess Y(I) [ΔCEF] giving the difference between Y(I) and Y(II) were used as an indicator of MAP-pathway and CEF activity, respectively. Although ΔY(II) was negligible and did not show positive relationship to the oxidation-state of P700, ΔCEF showed positive linear relationship to the oxidation-state of P700. These facts indicate that CEF cooperatively with photorespiration regulates the redox-state of P700 to suppress the over-reduction in PSI under environmental stress conditions.
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Affiliation(s)
- Daisuke Takagi
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Masaki Hashiguchi
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Takehiro Sejima
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Amane Makino
- Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai, 981-8555, Japan
| | - Chikahiro Miyake
- Department of Biological and Environmental Science, Faculty of Agriculture, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
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Nounjan N, Siangliw JL, Toojinda T, Chadchawan S, Theerakulpisut P. Salt-responsive mechanisms in chromosome segment substitution lines of rice (Oryza sativa L. cv. KDML105). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 103:96-105. [PMID: 26986930 DOI: 10.1016/j.plaphy.2016.02.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 02/17/2016] [Accepted: 02/26/2016] [Indexed: 05/21/2023]
Abstract
Two chromosome segment substitution lines of Khao Dawk Mali 105 (KDML105) rice that carry quantitative trait loci for drought tolerance located on chromosome 8 (DT-QTL8) designated CSSL8-94 and CSSL8-116 were investigated for co-expression network and physiological responses to salinity compared to their parents (KDML105; drought and salt sensitive recurrent parent, and DH103; drought tolerant QTL donor). These CSSL lines show different salt-response traits under salt stress (CSSL8-94 shows higher tolerance than CSSL8-116) and possess different segments of DT-QTL8. To identify specific biological process(es) associated with salt-stress response, co-expression network analysis was constructed from each DT-QTL segment. To evaluate differential physiological mechanisms responding to salt stress, all rice lines/cultivar were grown for 21 d in soils submerged in nutrient solutions, then subjected to 150 mM NaCl for 7 d. Physiological parameters related to co-expression network analysis (photosynthetic parameters) and salt responsive parameters (Na(+)/K(+) ratio, proline content, malondialdehyde and ascorbate peroxidase activity; EC1.11.1.1) were investigated along with the expression analysis of related genes. Physiological responses under salt stress particularly photosynthesis-related parameters of CSSL8-94 were similar to DH103, whereas those of CSSL8-116 were similar to KDML105. Moreover, expression levels of photosynthesis-related genes selected from the co-expression networks (Os08g41460, Os08g44680, Os06g01850, Os03g07300 and Os02g42570) were slightly decreased or stable in CSSL8-94 and DH103 but were dramatically down-regulated in CSSL8-116 and KDML105. These differential responses may contribute to the photosynthesis systems of CSSL8-94 being less damaged under salt stress in comparison to those of CSSL8-116. It can be concluded that the presence of the specific DT-QTL8 segment in CSSL8-94 not only confers drought tolerant traits but also enhances its salt tolerant ability.
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Affiliation(s)
- Noppawan Nounjan
- Salt-tolerant Rice Research Group, Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Jonaliza L Siangliw
- Rice Gene Discovery Laboratory, BIOTEC, NSTDA, Kasetsart University, Kamphaeng Saen Campus, Nakorn Pathom 73140, Thailand
| | - Theerayut Toojinda
- Rice Gene Discovery Laboratory, BIOTEC, NSTDA, Kasetsart University, Kamphaeng Saen Campus, Nakorn Pathom 73140, Thailand
| | - Supachitra Chadchawan
- Center of Excellence in Environment and Plant Physiology, Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Piyada Theerakulpisut
- Salt-tolerant Rice Research Group, Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
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Nakajima Munekage Y. Light harvesting and chloroplast electron transport in NADP-malic enzyme type C4 plants. CURRENT OPINION IN PLANT BIOLOGY 2016; 31:9-15. [PMID: 26999307 DOI: 10.1016/j.pbi.2016.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/17/2016] [Accepted: 03/01/2016] [Indexed: 06/05/2023]
Abstract
The structure of thylakoids in chloroplasts and the organization of the electron transport chain changed dynamically during the evolution of C4 photosynthesis, especially in the nicotinamide adenine dinucleotide phosphate (NADP)-malic enzyme type C4 species. Stacked grana membranes are strongly reduced in the bundle sheath chloroplasts of these plants, where photosystem II activity is diminished and cyclic electron transport around photosystem I mainly occurs. This change optimizes the ATP/NADPH production ratio in bundle sheath chloroplasts to drive the metabolic cycle of C4 photosynthesis. This review summarizes the current model of light harvesting and electron transport in the NADP-malic enzyme type C4 plants and discusses how it changed during the evolution of C4 photosynthesis.
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Affiliation(s)
- Yuri Nakajima Munekage
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
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Munekage YN, Taniguchi YY. Promotion of Cyclic Electron Transport Around Photosystem I with the Development of C4 Photosynthesis. PLANT & CELL PHYSIOLOGY 2016; 57:897-903. [PMID: 26893472 DOI: 10.1093/pcp/pcw012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/11/2016] [Indexed: 06/05/2023]
Abstract
C4 photosynthesis is present in approximately 7,500 species classified into 19 families, including monocots and eudicots. In the majority of documented cases, a two-celled CO2-concentrating system that uses a metabolic cycle of four-carbon compounds is employed. C4 photosynthesis repeatedly evolved from C3 photosynthesis, possibly driven by the survival advantages it bestows in the hot, often dry, and nutrient-poor soils of the tropics and subtropics. The development of the C4 metabolic cycle greatly increased the ATP demand in chloroplasts during the evolution of malic enzyme-type C4 photosynthesis, and the additional ATP required for C4 metabolism may be produced by the cyclic electron transport around PSI. Recent studies have revealed the nature of cyclic electron transport and the elevation of its components during C4 evolution. In this review, we discuss the energy requirements of C3 and C4 photosynthesis, the current model of cyclic electron transport around PSI and how cyclic electron transport is promoted during C4 evolution using studies on the genus Flaveria, which contains a number of closely related C3, C4 and C3-C4 intermediate species.
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Affiliation(s)
- Yuri Nakajima Munekage
- School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337 Japan
| | - Yukimi Y Taniguchi
- School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337 Japan
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