1
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Hippler M, Khosravitabar F. Light-Driven H 2 Production in Chlamydomonas reinhardtii: Lessons from Engineering of Photosynthesis. PLANTS (BASEL, SWITZERLAND) 2024; 13:2114. [PMID: 39124233 PMCID: PMC11314271 DOI: 10.3390/plants13152114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 07/22/2024] [Accepted: 07/25/2024] [Indexed: 08/12/2024]
Abstract
In the green alga Chlamydomonas reinhardtii, hydrogen production is catalyzed via the [FeFe]-hydrogenases HydA1 and HydA2. The electrons required for the catalysis are transferred from ferredoxin (FDX) towards the hydrogenases. In the light, ferredoxin receives its electrons from photosystem I (PSI) so that H2 production becomes a fully light-driven process. HydA1 and HydA2 are highly O2 sensitive; consequently, the formation of H2 occurs mainly under anoxic conditions. Yet, photo-H2 production is tightly coupled to the efficiency of photosynthetic electron transport and linked to the photosynthetic control via the Cyt b6f complex, the control of electron transfer at the level of photosystem II (PSII) and the structural remodeling of photosystem I (PSI). These processes also determine the efficiency of linear (LEF) and cyclic electron flow (CEF). The latter is competitive with H2 photoproduction. Additionally, the CBB cycle competes with H2 photoproduction. Consequently, an in-depth understanding of light-driven H2 production via photosynthetic electron transfer and its competition with CO2 fixation is essential for improving photo-H2 production. At the same time, the smart design of photo-H2 production schemes and photo-H2 bioreactors are challenges for efficient up-scaling of light-driven photo-H2 production.
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Affiliation(s)
- Michael Hippler
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - Fatemeh Khosravitabar
- Department of Biological and Environmental Sciences, University of Gothenburg, 40530 Gothenburg, Sweden
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2
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Milrad Y, Mosebach L, Buchert F. Regulation of Microalgal Photosynthetic Electron Transfer. PLANTS (BASEL, SWITZERLAND) 2024; 13:2103. [PMID: 39124221 PMCID: PMC11314055 DOI: 10.3390/plants13152103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 07/24/2024] [Accepted: 07/26/2024] [Indexed: 08/12/2024]
Abstract
The global ecosystem relies on the metabolism of photosynthetic organisms, featuring the ability to harness light as an energy source. The most successful type of photosynthesis utilizes a virtually inexhaustible electron pool from water, but the driver of this oxidation, sunlight, varies on time and intensity scales of several orders of magnitude. Such rapid and steep changes in energy availability are potentially devastating for biological systems. To enable a safe and efficient light-harnessing process, photosynthetic organisms tune their light capturing, the redox connections between core complexes and auxiliary electron mediators, ion passages across the membrane, and functional coupling of energy transducing organelles. Here, microalgal species are the most diverse group, featuring both unique environmental adjustment strategies and ubiquitous protective mechanisms. In this review, we explore a selection of regulatory processes of the microalgal photosynthetic apparatus supporting smooth electron flow in variable environments.
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Affiliation(s)
- Yuval Milrad
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Laura Mosebach
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
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3
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Deore P, Tsang Min Ching SJ, Nitschke MR, Rudd D, Brumley DR, Hinde E, Blackall LL, van Oppen MJH. Unique photosynthetic strategies employed by closely related Breviolum minutum strains under rapid short-term cumulative heat stress. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:4005-4023. [PMID: 38636949 PMCID: PMC11233414 DOI: 10.1093/jxb/erae170] [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: 11/20/2023] [Accepted: 04/17/2024] [Indexed: 04/20/2024]
Abstract
The thermal tolerance of symbiodiniacean photo-endosymbionts largely underpins the thermal bleaching resilience of their cnidarian hosts such as corals and the coral model Exaiptasia diaphana. While variation in thermal tolerance between species is well documented, variation between conspecific strains is understudied. We compared the thermal tolerance of three closely related strains of Breviolum minutum represented by two internal transcribed spacer region 2 profiles (one strain B1-B1o-B1g-B1p and the other two strains B1-B1a-B1b-B1g) and differences in photochemical and non-photochemical quenching, de-epoxidation state of photopigments, and accumulation of reactive oxygen species under rapid short-term cumulative temperature stress (26-40 °C). We found that B. minutum strains employ distinct photoprotective strategies, resulting in different upper thermal tolerances. We provide evidence for previously unknown interdependencies between thermal tolerance traits and photoprotective mechanisms that include a delicate balancing of excitation energy and its dissipation through fast relaxing and state transition components of non-photochemical quenching. The more thermally tolerant B. minutum strain (B1-B1o-B1g-B1p) exhibited an enhanced de-epoxidation that is strongly linked to the thylakoid membrane melting point and possibly membrane rigidification minimizing oxidative damage. This study provides an in-depth understanding of photoprotective mechanisms underpinning thermal tolerance in closely related strains of B. minutum.
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Affiliation(s)
- Pranali Deore
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
| | | | - Matthew R Nitschke
- Australian Institute of Marine Science, Townsville 4810, Queensland, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington 6102, New Zealand
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Douglas R Brumley
- School of Mathematics and Statistics, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Elizabeth Hinde
- School of Physics, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Linda L Blackall
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
- Australian Institute of Marine Science, Townsville 4810, Queensland, Australia
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4
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Shikanai T. Molecular Genetic Dissection of the Regulatory Network of Proton Motive Force in Chloroplasts. PLANT & CELL PHYSIOLOGY 2024; 65:537-550. [PMID: 38150384 DOI: 10.1093/pcp/pcad157] [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: 10/16/2023] [Revised: 11/27/2023] [Accepted: 12/08/2023] [Indexed: 12/29/2023]
Abstract
The proton motive force (pmf) generated across the thylakoid membrane rotates the Fo-ring of ATP synthase in chloroplasts. The pmf comprises two components: membrane potential (∆Ψ) and proton concentration gradient (∆pH). Acidification of the thylakoid lumen resulting from ∆pH downregulates electron transport in the cytochrome b6f complex. This process, known as photosynthetic control, is crucial for protecting photosystem I (PSI) from photodamage in response to fluctuating light. To optimize the balance between efficient photosynthesis and photoprotection, it is necessary to regulate pmf. Cyclic electron transport around PSI and pseudo-cyclic electron transport involving flavodiiron proteins contribute to the modulation of pmf magnitude. By manipulating the ratio between the two components of pmf, it is possible to modify the extent of photosynthetic control without affecting the pmf size. This adjustment can be achieved by regulating the movement of ions (such as K+ and Cl-) across the thylakoid membrane. Since ATP synthase is the primary consumer of pmf in chloroplasts, its activity must be precisely regulated to accommodate other mechanisms involved in pmf optimization. Although fragments of information about each regulatory process have been accumulated, a comprehensive understanding of their interactions is lacking. Here, I summarize current knowledge of the network for pmf regulation, mainly based on genetic studies.
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Affiliation(s)
- Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto, 606-8502 Japan
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5
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Ozawa SI, Zhang G, Sakamoto W. Dysfunction of Chloroplast Protease Activity Mitigates pgr5 Phenotype in the Green Algae Chlamydomonas reinhardtii. PLANTS (BASEL, SWITZERLAND) 2024; 13:606. [PMID: 38475453 DOI: 10.3390/plants13050606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/16/2024] [Accepted: 02/18/2024] [Indexed: 03/14/2024]
Abstract
Researchers have described protection mechanisms against the photoinhibition of photosystems under strong-light stress. Cyclic Electron Flow (CEF) mitigates electron acceptor-side limitation, and thus contributes to Photosystem I (PSI) protection. Chloroplast protease removes damaged protein to assist with protein turn over, which contributes to the quality control of Photosystem II (PSII). The PGR5 protein is involved in PGR5-dependent CEF. The FTSH protein is a chloroplast protease which effectively degrades the damaged PSII reaction center subunit, D1 protein. To investigate how the PSI photoinhibition phenotype in pgr5 would be affected by adding the ftsh mutation, we generated double-mutant pgr5ftsh via crossing, and its phenotype was characterized in the green algae Chlamydomonas reinhardtii. The cells underwent high-light incubation as well as low-light incubation after high-light incubation. The time course of Fv/Fm values in pgr5ftsh showed the same phenotype with ftsh1-1. The amplitude of light-induced P700 photo-oxidation absorbance change was measured. The amplitude was maintained at a low value in the control and pgr5ftsh during high-light incubation, but was continuously decreased in pgr5. During the low-light incubation after high-light incubation, amplitude was more rapidly recovered in pgr5ftsh than pgr5. We concluded that the PSI photoinhibition by the pgr5 mutation is mitigated by an additional ftsh1-1 mutation, in which plastoquinone pool would be less reduced due to damaged PSII accumulation.
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Affiliation(s)
- Shin-Ichiro Ozawa
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - Guoxian Zhang
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China
| | - Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
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6
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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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7
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Hehenberger E, Guo J, Wilken S, Hoadley K, Sudek L, Poirier C, Dannebaum R, Susko E, Worden AZ. Phosphate Limitation Responses in Marine Green Algae Are Linked to Reprogramming of the tRNA Epitranscriptome and Codon Usage Bias. Mol Biol Evol 2023; 40:msad251. [PMID: 37987557 PMCID: PMC10735309 DOI: 10.1093/molbev/msad251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 11/14/2023] [Accepted: 11/16/2023] [Indexed: 11/22/2023] Open
Abstract
Marine algae are central to global carbon fixation, and their productivity is dictated largely by resource availability. Reduced nutrient availability is predicted for vast oceanic regions as an outcome of climate change; however, there is much to learn regarding response mechanisms of the tiny picoplankton that thrive in these environments, especially eukaryotic phytoplankton. Here, we investigate responses of the picoeukaryote Micromonas commoda, a green alga found throughout subtropical and tropical oceans. Under shifting phosphate availability scenarios, transcriptomic analyses revealed altered expression of transfer RNA modification enzymes and biased codon usage of transcripts more abundant during phosphate-limiting versus phosphate-replete conditions, consistent with the role of transfer RNA modifications in regulating codon recognition. To associate the observed shift in the expression of the transfer RNA modification enzyme complement with the transfer RNAs encoded by M. commoda, we also determined the transfer RNA repertoire of this alga revealing potential targets of the modification enzymes. Codon usage bias was particularly pronounced in transcripts encoding proteins with direct roles in managing phosphate limitation and photosystem-associated proteins that have ill-characterized putative functions in "light stress." The observed codon usage bias corresponds to a proposed stress response mechanism in which the interplay between stress-induced changes in transfer RNA modifications and skewed codon usage in certain essential response genes drives preferential translation of the encoded proteins. Collectively, we expose a potential underlying mechanism for achieving growth under enhanced nutrient limitation that extends beyond the catalog of up- or downregulated protein-encoding genes to the cell biological controls that underpin acclimation to changing environmental conditions.
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Affiliation(s)
- Elisabeth Hehenberger
- Ocean EcoSystems Biology Unit, RD3, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, DE
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, CZ
| | - Jian Guo
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Susanne Wilken
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Kenneth Hoadley
- Ocean EcoSystems Biology Unit, RD3, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, DE
| | - Lisa Sudek
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Camille Poirier
- Ocean EcoSystems Biology Unit, RD3, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, DE
| | - Richard Dannebaum
- Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Edward Susko
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia B3H 4R2, CA
| | - Alexandra Z Worden
- Ocean EcoSystems Biology Unit, RD3, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, DE
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA 95064, USA
- Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA 02543, USA
- Max Planck Institute for Evolutionary Biology, 24306 Plön, DE
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8
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Burlacot A. Quantifying the roles of algal photosynthetic electron pathways: a milestone towards photosynthetic robustness. THE NEW PHYTOLOGIST 2023; 240:2197-2203. [PMID: 37872749 DOI: 10.1111/nph.19328] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 09/01/2023] [Indexed: 10/25/2023]
Abstract
During photosynthesis, electron transport reactions generate and shuttle reductant to allow CO2 reduction by the Calvin-Benson-Bassham cycle and the formation of biomass building block in the so-called linear electron flow (LEF). However, in nature, environmental parameters like light intensity or CO2 availability can vary and quickly change photosynthesis rates, creating an imbalance between photosynthetic energy production and metabolic needs. In addition to LEF, alternative photosynthetic electron flows are central to allow photosynthetic energy to match metabolic demand in response to environmental variations. Microalgae arguably harbour one of the most diverse set of alternative electron flows (AEFs), including cyclic (CEF), pseudocyclic (PCEF) and chloroplast-to-mitochondria (CMEF) electron flow. While CEF, PCEF and CMEF have large functional overlaps, they differ in the conditions they are active and in their role for photosynthetic energy balance. Here, I review the molecular mechanisms of CEF, PCEF and CMEF in microalgae. I further propose a quantitative framework to compare their key physiological roles and quantify how the photosynthetic energy is partitioned to maintain a balanced energetic status of the cell. Key differences in AEF within the green lineage and the potential of rewiring photosynthetic electrons to enhance plant robustness will be discussed.
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Affiliation(s)
- Adrien Burlacot
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
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9
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Chouhan N, Marriboina S, Kumari A, Singh P, Yadav RM, Gupta KJ, Subramanyam R. Metabolomic response to high light from pgrl1 and pgr5 mutants of Chlamydomonas reinhardtii. Photochem Photobiol Sci 2023; 22:2635-2650. [PMID: 37751074 DOI: 10.1007/s43630-023-00478-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 08/31/2023] [Indexed: 09/27/2023]
Abstract
Chlamydomonas (C.) reinhardtii metabolomic changes in cyclic electron flow-dependent mutants are still unknown. Here, we used mass spectrometric analysis to monitor the changes in metabolite levels in wild-type, cyclic electron-deficient mutants pgrl1 and pgr5 grown under high-light stress. A total of 55 metabolites were detected using GC-MS analysis. High-light stress-induced selective anaplerotic amino acids in pgr5. In addition, pgr5 showed enhancement in carbohydrate, polyamine, and polyol metabolism by 2.5-fold under high light. In response to high light, pgr5 triggers an increase in several metabolites involved in regulating osmotic pressure. Among these metabolites are glycerol pathway compounds such as glycerol-3-phosphate and glyceryl-glycoside, which increase significantly by 1.55 and 3.07 times, respectively. In addition, pgr5 also enhanced proline and putrescine levels by 2.6- and 1.36-fold under high light. On the other hand, pgrl1-induced metabolites, such as alanine and serine, are crucial for photorespiration when subjected to high-light stress. We also observed a significant increase in levels of polyols and glycerol by 1.37- and 2.97-fold in pgrl1 under high-light stress. Both correlation network studies and KEGG pathway enrichment analysis revealed that metabolites related to several biological pathways, such as amino acid, carbohydrate, TCA cycle, and fatty acid metabolism, were positively correlated in pgrl1 and pgr5 under high-light stress conditions. The relative mRNA expression levels of genes related to the TCA cycle, including PDC3, ACH1, OGD2, OGD3, IDH3, and MDH4, were significantly upregulated in pgrl1 and pgr5 under HL. In pgr5, the MDH1 level was significantly increased, while ACS1, ACS3, IDH2, and IDH3 levels were reduced considerably in pgrl1 under high-light stress. The current study demonstrates both pgr5 and prgl1 showed a differential defense response to high-light stress at the primary metabolites and mRNA expression level, which can be added to the existing knowledge to explore molecular regulatory responses of prg5 and pgrl1 to high-light stress.
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Affiliation(s)
- Nisha Chouhan
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Sureshbabu Marriboina
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
- The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben Gurion, 8499000, Beersheba, Israel
| | - Aprajita Kumari
- National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Pooja Singh
- National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Ranay Mohan Yadav
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | | | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India.
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10
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Cantrell M, Ware MA, Peers G. Characterizing compensatory mechanisms in the absence of photoprotective qE in Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2023; 158:23-39. [PMID: 37488319 DOI: 10.1007/s11120-023-01037-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 06/26/2023] [Indexed: 07/26/2023]
Abstract
Rapid fluctuations in the quantity and quality of natural light expose photosynthetic organisms to conditions when the capacity to utilize absorbed quanta is insufficient. These conditions can result in the production of reactive oxygen species and photooxidative damage. Non-photochemical quenching (NPQ) and alternative electron transport are the two most prominent mechanisms which synergistically function to minimize the overreduction of photosystems. In the green alga Chlamydomonas reinhardtii, the stress-related light-harvesting complex (LHCSR) is a required component for the rapid induction and relaxation of NPQ in the light-harvesting antenna. Here, we use simultaneous chlorophyll fluorescence and oxygen exchange measurements to characterize the acclimation of the Chlamydomonas LHCSR-less mutant (npq4lhcsr1) to saturating light conditions. We demonstrate that, in the absence of NPQ, Chlamydomonas does not acclimate to sinusoidal light through increased light-dependent oxygen consumption. We also show that the npq4lhcsr1 mutant has an increased sink capacity downstream of PSI and this energy flow is likely facilitated by cyclic electron transport. Furthermore, we show that the timing of additions of mitochondrial inhibitors has a major influence on plastid/mitochondrial coupling experiments.
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Affiliation(s)
- Michael Cantrell
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Maxwell A Ware
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Graham Peers
- Department of Biology, Colorado State University, Fort Collins, CO, USA.
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11
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Burlacot A, Peltier G. Energy crosstalk between photosynthesis and the algal CO 2-concentrating mechanisms. TRENDS IN PLANT SCIENCE 2023; 28:795-807. [PMID: 37087359 DOI: 10.1016/j.tplants.2023.03.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 03/16/2023] [Accepted: 03/18/2023] [Indexed: 05/03/2023]
Abstract
Microalgal photosynthesis is responsible for nearly half of the CO2 annually captured by Earth's ecosystems. In aquatic environments where the CO2 availability is low, the CO2-fixing efficiency of microalgae greatly relies on mechanisms - called CO2-concentrating mechanisms (CCMs) - for concentrating CO2 at the catalytic site of the CO2-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). While the transport of inorganic carbon (Ci) across membrane bilayers against a concentration gradient consumes part of the chemical energy generated by photosynthesis, the bioenergetics and cellular mechanisms involved are only beginning to be elucidated. Here, we review the current knowledge relating to the energy requirement of CCMs in the light of recent advances in photosynthesis regulatory mechanisms and the spatial organization of CCM components.
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Affiliation(s)
- Adrien Burlacot
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA.
| | - Gilles Peltier
- Aix-Marseille Université, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France.
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12
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Herdean A, Hall C, Hughes DJ, Kuzhiumparambil U, Diocaretz BC, Ralph PJ. Temperature mapping of non-photochemical quenching in Chlorella vulgaris. PHOTOSYNTHESIS RESEARCH 2023; 155:191-202. [PMID: 36417105 PMCID: PMC9879819 DOI: 10.1007/s11120-022-00981-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Light intensity and temperature independently impact all parts of the photosynthetic machinery in plants and algae. Yet to date, the vast majority of pulse amplitude modulated (PAM) chlorophyll a fluorescence measurements have been performed at well-defined light intensities, but rarely at well-defined temperatures. In this work, we show that PAM measurements performed at various temperatures produce vastly different results in the chlorophyte Chlorella vulgaris. Using a recently developed Phenoplate technique to map quantum yield of Photosystem II (Y(II)) and non-photochemical quenching (NPQ) as a function of temperature, we show that the fast-relaxing NPQ follows an inverse normal distribution with respect to temperature and appears insensitive to previous temperature acclimation. The slow-relaxing or residual NPQ after 5 minutes of dark recovery follows a normal distribution similar to Y(II) but with a peak in the higher temperature range. Surprisingly, higher slow- and fast-relaxing NPQ values were observed in high-light relative to low-light acclimated cultures. Y(II) values peaked at the adaptation temperature regardless of temperature or light acclimation. Our novel findings show the complete temperature working spectrum of Y(II) and how excess energy quenching is managed across a wide range of temperatures in the model microalgal species C. vulgaris. Finally, we draw attention to the fact that the effect of the temperature component in PAM measurements has been wildly underestimated, and results from experiments at room temperature can be misleading.
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Affiliation(s)
- Andrei Herdean
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
| | - Christopher Hall
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - David J Hughes
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | | | | | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia
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13
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Chouhan N, Yadav RM, Pandey J, Subramanyam R. High light-induced changes in thylakoid supercomplexes organization from cyclic electron transport mutants of Chlamydomonas reinhardtii. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148917. [PMID: 36108725 DOI: 10.1016/j.bbabio.2022.148917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 09/03/2022] [Accepted: 09/08/2022] [Indexed: 11/15/2022]
Abstract
The localization of carotenoids and macromolecular organization of thylakoid supercomplexes have not been reported yet in Chlamydomonas reinhardtii WT and cyclic electron transport mutants (pgrl1 and pgr5) under high light. Here, the various pigments, protein composition, and pigment-protein interactions were analyzed from the cells, thylakoids, and sucrose density gradient (SDG) fractions. Also, the supercomplexes of thylakoids were separated from BN-PAGE and SDG. The abundance of light-harvesting complex (LHC) II trimer complexes and pigment-pigment interaction were changed slightly under high light, shown by circular dichroism. However, a drastic change was seen in photosystem (PS)I-LHCI complexes than PSII complexes, especially in pgrl1 and pgr5. The lutein and β-carotene increased under high light in LHCII trimers compared to other supercomplexes, indicating that these pigments protected the LHCII trimers against high light. However, the presence of xanthophylls, lutein, and β-carotene was less in PSI-LHCI, indicating that pigment-protein complexes altered in high light. Even the real-time PCR data shows that the pgr5 mutant does not accumulate zeaxanthin dependent genes under high light, which shows that violaxanthin is not converting into zeaxanthin under high light. Also, the protein data confirms that the LHCSR3 expression is absent in pgr5, however it is presented in LHCII trimer in WT and pgrl1. Interestingly, some of the core proteins were aggregated in pgr5, which led to change in photosynthesis efficiency in high light.
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Affiliation(s)
- Nisha Chouhan
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Ranay Mohan Yadav
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Jayendra Pandey
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
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14
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Liu P, Ye DM, Chen M, Zhang J, Huang XH, Shen LL, Xia KK, Xu XJ, Xu YC, Guo YL, Wang YC, Huang F. Scaling-up and proteomic analysis reveals photosynthetic and metabolic insights toward prolonged H 2 photoproduction in Chlamydomonas hpm91 mutant lacking proton gradient regulation 5 (PGR5). PHOTOSYNTHESIS RESEARCH 2022; 154:397-411. [PMID: 35974136 PMCID: PMC9722884 DOI: 10.1007/s11120-022-00945-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Clean and sustainable H2 production is crucial to a carbon-neutral world. H2 generation by Chlamydomonas reinhardtii is an attractive approach for solar-H2 from H2O. However, it is currently not large-scalable because of lacking desirable strains with both optimal H2 productivity and sufficient knowledge of underlying molecular mechanism. We hereby carried out extensive and in-depth investigations of H2 photoproduction of hpm91 mutant lacking PGR5 (Proton Gradient Regulation 5) toward its up-scaling and fundamental mechanism issues. We show that hpm91 is at least 100-fold scalable (up to 10 L) with continuous H2 collection of 7287 ml H2/10L-HPBR in averagely 26 days under sulfur deprivation. Also, we show that hpm91 is robust and active during sustained H2 photoproduction, most likely due to decreased intracellular ROS relative to wild type. Moreover, we obtained quantitative proteomic profiles of wild type and hpm91 at four representing time points of H2 evolution, leading to 2229 and 1350 differentially expressed proteins, respectively. Compared to wild type, major proteome alterations of hpm91 include not only core subunits of photosystems and those related to anti-oxidative responses but also essential proteins in photosynthetic antenna, C/N metabolic balance, and sulfur assimilation toward both cysteine biosynthesis and sulfation of metabolites during sulfur-deprived H2 production. These results reveal not only new insights of cellular and molecular basis of enhanced H2 production in hpm91 but also provide additional candidate gene targets and modules for further genetic modifications and/or in artificial photosynthesis mimics toward basic and applied research aiming at advancing solar-H2 technology.
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Affiliation(s)
- Peng Liu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - De-Min Ye
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mei Chen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jin Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xia-He Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Li-Li Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ke-Ke Xia
- BGI-Shenzhen, Shenzhen, 518083, China
| | - Xiao-Jing Xu
- BGI-Shenzhen, Shenzhen, 518083, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong-Chao Xu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ya-Long Guo
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Ying-Chun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Fang Huang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
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15
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Bai R, Bai C, Han X, Liu Y, Yong JWH. The significance of calcium-sensing receptor in sustaining photosynthesis and ameliorating stress responses in plants. FRONTIERS IN PLANT SCIENCE 2022; 13:1019505. [PMID: 36304398 PMCID: PMC9594963 DOI: 10.3389/fpls.2022.1019505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Calcium ions (Ca2+) regulate plant growth and development during exposure to multiple biotic and abiotic stresses as the second signaling messenger in cells. The extracellular calcium-sensing receptor (CAS) is a specific protein spatially located on the thylakoid membrane. It regulates the intracellular Ca2+ responses by sensing changes in extracellular Ca2+ concentration, thereby affecting a series of downstream signal transduction processes and making plants more resilient to respond to stresses. Here, we summarized the discovery process, structure, and location of CAS in plants and the effects of Ca2+ and CAS on stomatal functionality, photosynthesis, and various environmental adaptations. Under changing environmental conditions and global climate, our study enhances the mechanistic understanding of calcium-sensing receptors in sustaining photosynthesis and mediating abiotic stress responses in plants. A better understanding of the fundamental mechanisms of Ca2+ and CAS in regulating stress responses in plants may provide novel mitigation strategies for improving crop yield in a world facing more extreme climate-changed linked weather events with multiple stresses during cultivation.
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Affiliation(s)
- Rui Bai
- College of Land and Environment, National Engineering Research Center 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
| | - Chunming Bai
- National Sorghum Improvement Center, Liaoning Academy of Agricultural Sciences, Shenyang, China
- The University of Western Australia (UWA) Institute of Agriculture, The University of Western Australia, Perth, WA, Australia
| | - Xiaori Han
- College of Land and Environment, National Engineering Research Center 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 Engineering Research Center 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 University of Western Australia (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
| | - 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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16
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Leister D, Marino G, Minagawa J, Dann M. An ancient function of PGR5 in iron delivery? TRENDS IN PLANT SCIENCE 2022; 27:971-980. [PMID: 35618596 DOI: 10.1016/j.tplants.2022.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/29/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
In all phototrophic organisms, the photosynthetic apparatus must be protected from light-induced damage. One important mechanism that mitigates photodamage in plants is antimycin A (AA)-sensitive cyclic electron flow (CEF), the evolution of which remains largely obscure. Here we show that proton gradient regulation 5 (PGR5), a key protein involved in AA-sensitive CEF, displays intriguing commonalities - including sequence and structural features - with a group of ferritin-like proteins. We therefore propose that PGR5 may originally have been involved in prokaryotic iron mobilization and delivery, which facilitated a primordial type of CEF as a side effect. The abandonment of the bacterioferritin system during the transformation of cyanobacterial endosymbionts into chloroplasts might have allowed PGR5 to functionally specialize in CEF.
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Affiliation(s)
- Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
| | - Giada Marino
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Marcel Dann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, D-82152 Planegg-Martinsried, Germany; Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
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17
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Takahashi H. Cyclic electron flow A to Z. JOURNAL OF PLANT RESEARCH 2022; 135:539-541. [PMID: 35727481 DOI: 10.1007/s10265-022-01402-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- Hiroko Takahashi
- Department of Biochemistry and Molecular Biology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan.
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18
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Zhang N, Mattoon EM, McHargue W, Venn B, Zimmer D, Pecani K, Jeong J, Anderson CM, Chen C, Berry JC, Xia M, Tzeng SC, Becker E, Pazouki L, Evans B, Cross F, Cheng J, Czymmek KJ, Schroda M, Mühlhaus T, Zhang R. Systems-wide analysis revealed shared and unique responses to moderate and acute high temperatures in the green alga Chlamydomonas reinhardtii. Commun Biol 2022; 5:460. [PMID: 35562408 PMCID: PMC9106746 DOI: 10.1038/s42003-022-03359-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 04/12/2022] [Indexed: 12/15/2022] Open
Abstract
Different intensities of high temperatures affect the growth of photosynthetic cells in nature. To elucidate the underlying mechanisms, we cultivated the unicellular green alga Chlamydomonas reinhardtii under highly controlled photobioreactor conditions and revealed systems-wide shared and unique responses to 24-hour moderate (35°C) and acute (40°C) high temperatures and subsequent recovery at 25°C. We identified previously overlooked unique elements in response to moderate high temperature. Heat at 35°C transiently arrested the cell cycle followed by partial synchronization, up-regulated transcripts/proteins involved in gluconeogenesis/glyoxylate-cycle for carbon uptake and promoted growth. But 40°C disrupted cell division and growth. Both high temperatures induced photoprotection, while 40°C distorted thylakoid/pyrenoid ultrastructure, affected the carbon concentrating mechanism, and decreased photosynthetic efficiency. We demonstrated increased transcript/protein correlation during both heat treatments and hypothesize reduced post-transcriptional regulation during heat may help efficiently coordinate thermotolerance mechanisms. During recovery after both heat treatments, especially 40°C, transcripts/proteins related to DNA synthesis increased while those involved in photosynthetic light reactions decreased. We propose down-regulating photosynthetic light reactions during DNA replication benefits cell cycle resumption by reducing ROS production. Our results provide potential targets to increase thermotolerance in algae and crops. A systems-wide analysis of the single-cell green alga Chlamydomonas reinhardti reveals shared and unique responses to moderate and acute high temperatures using multiple-level investigation of transcriptomics, proteomics, cell physiology, photosynthetic parameters, and cellular ultrastructure.
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Affiliation(s)
- Ningning Zhang
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Erin M Mattoon
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA.,Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, Missouri, 63130, USA
| | - Will McHargue
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA.,Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, Missouri, 63130, USA
| | | | - David Zimmer
- TU Kaiserslautern, Kaiserslautern, 67663, Germany
| | - Kresti Pecani
- The Rockefeller University, New York, New York, 10065, USA
| | - Jooyeon Jeong
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Cheyenne M Anderson
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA.,Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, Missouri, 63130, USA
| | - Chen Chen
- University of Missouri-Columbia, Columbia, Missouri, 65211, USA
| | - Jeffrey C Berry
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Ming Xia
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Shin-Cheng Tzeng
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Eric Becker
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Leila Pazouki
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Bradley Evans
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | - Fred Cross
- The Rockefeller University, New York, New York, 10065, USA
| | - Jianlin Cheng
- University of Missouri-Columbia, Columbia, Missouri, 65211, USA
| | - Kirk J Czymmek
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA
| | | | | | - Ru Zhang
- Donald Danforth Plant Science Center, St. Louis, Missouri, 63132, USA.
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19
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Ho TTH, Schwier C, Elman T, Fleuter V, Zinzius K, Scholz M, Yacoby I, Buchert F, Hippler M. Photosystem I light-harvesting proteins regulate photosynthetic electron transfer and hydrogen production. PLANT PHYSIOLOGY 2022; 189:329-343. [PMID: 35157085 PMCID: PMC9070821 DOI: 10.1093/plphys/kiac055] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/23/2022] [Indexed: 05/06/2023]
Abstract
Linear electron flow (LEF) and cyclic electron flow (CEF) compete for light-driven electrons transferred from the acceptor side of photosystem I (PSI). Under anoxic conditions, such highly reducing electrons also could be used for hydrogen (H2) production via electron transfer between ferredoxin and hydrogenase in the green alga Chlamydomonas reinhardtii. Partitioning between LEF and CEF is regulated through PROTON-GRADIENT REGULATION5 (PGR5). There is evidence that partitioning of electrons also could be mediated via PSI remodeling processes. This plasticity is linked to the dynamics of PSI-associated light-harvesting proteins (LHCAs) LHCA2 and LHCA9. These two unique light-harvesting proteins are distinct from all other LHCAs because they are loosely bound at the PSAL pole. Here, we investigated photosynthetic electron transfer and H2 production in single, double, and triple mutants deficient in PGR5, LHCA2, and LHCA9. Our data indicate that lhca2 and lhca9 mutants are efficient in photosynthetic electron transfer, that LHCA2 impacts the pgr5 phenotype, and that pgr5/lhca2 is a potent H2 photo-producer. In addition, pgr5/lhca2 and pgr5/lhca9 mutants displayed substantially different H2 photo-production kinetics. This indicates that the absence of LHCA2 or LHCA9 impacts H2 photo-production independently, despite both being attached at the PSAL pole, pointing to distinct regulatory capacities.
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Affiliation(s)
- Thi Thu Hoai Ho
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
- Faculty of Fisheries, University of Agriculture and Forestry, Hue University, Hue 530000, Vietnam
| | - Chris Schwier
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Tamar Elman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Vera Fleuter
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Karen Zinzius
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Martin Scholz
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, Münster 48143, Germany
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20
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Burlacot A, Dao O, Auroy P, Cuiné S, Li-Beisson Y, Peltier G. Alternative photosynthesis pathways drive the algal CO 2-concentrating mechanism. Nature 2022; 605:366-371. [PMID: 35477755 DOI: 10.1038/s41586-022-04662-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 03/18/2022] [Indexed: 12/13/2022]
Abstract
Global photosynthesis consumes ten times more CO2 than net anthropogenic emissions, and microalgae account for nearly half of this consumption1. The high efficiency of algal photosynthesis relies on a mechanism concentrating CO2 (CCM) at the catalytic site of the carboxylating enzyme RuBisCO, which enhances CO2 fixation2. Although many cellular components involved in the transport and sequestration of inorganic carbon have been identified3,4, how microalgae supply energy to concentrate CO2 against a thermodynamic gradient remains unknown4-6. Here we show that in the green alga Chlamydomonas reinhardtii, the combined action of cyclic electron flow and O2 photoreduction-which depend on PGRL1 and flavodiiron proteins, respectively-generate a low luminal pH that is essential for CCM function. We suggest that luminal protons are used downstream of thylakoid bestrophin-like transporters, probably for the conversion of bicarbonate to CO2. We further establish that an electron flow from chloroplast to mitochondria contributes to energizing non-thylakoid inorganic carbon transporters, probably by supplying ATP. We propose an integrated view of the network supplying energy to the CCM, and describe how algal cells distribute energy from photosynthesis to power different CCM processes. These results suggest a route for the transfer of a functional algal CCM to plants to improve crop productivity.
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Affiliation(s)
- Adrien Burlacot
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France.,Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Ousmane Dao
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Pascaline Auroy
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Stephan Cuiné
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France.
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21
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Saint-Sorny M, Brzezowski P, Arrivault S, Alric J, Johnson X. Interactions Between Carbon Metabolism and Photosynthetic Electron Transport in a Chlamydomonas reinhardtii Mutant Without CO 2 Fixation by RuBisCO. FRONTIERS IN PLANT SCIENCE 2022; 13:876439. [PMID: 35574084 PMCID: PMC9096841 DOI: 10.3389/fpls.2022.876439] [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: 02/15/2022] [Accepted: 03/31/2022] [Indexed: 06/15/2023]
Abstract
A Chlamydomonas reinhardtii RuBisCO-less mutant, ΔrbcL, was used to study carbohydrate metabolism without fixation of atmospheric carbon. The regulatory mechanism(s) that control linear electron flow, known as "photosynthetic control," are amplified in ΔrbcL at the onset of illumination. With the aim to understand the metabolites that control this regulatory response, we have correlated the kinetics of primary carbon metabolites to chlorophyll fluorescence induction curves. We identify that ΔrbcL in the absence of acetate generates adenosine triphosphate (ATP) via photosynthetic electron transfer reactions. Also, metabolites of the Calvin Benson Bassham (CBB) cycle are responsive to the light. Indeed, ribulose 1,5-bisphosphate (RuBP), the last intermediate before carboxylation by Ribulose-1,5-bisphosphate carboxylase-oxygenase, accumulates significantly with time, and CBB cycle intermediates for RuBP regeneration, dihydroxyacetone phosphate (DHAP), pentose phosphates and ribose-5-phosphate (R5P) are rapidly accumulated in the first seconds of illumination, then consumed, showing that although the CBB is blocked, these enzymes are still transiently active. In opposition, in the presence of acetate, consumption of CBB cycle intermediates is strongly diminished, suggesting that the link between light and primary carbon metabolism is almost lost. Phosphorylated hexoses and starch accumulate significantly. We show that acetate uptake results in heterotrophic metabolism dominating phototrophic metabolism, with glyoxylate and tricarboxylic acid (TCA) cycle intermediates being the most highly represented metabolites, specifically succinate and malate. These findings allow us to hypothesize which metabolites and metabolic pathways are relevant to the upregulation of processes like cyclic electron flow that are implicated in photosynthetic control mechanisms.
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Affiliation(s)
- Maureen Saint-Sorny
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | - Pawel Brzezowski
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | | | - Jean Alric
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
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22
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King SJ, Jerkovic A, Brown LJ, Petroll K, Willows RD. Synthetic biology for improved hydrogen production in Chlamydomonas reinhardtii. Microb Biotechnol 2022; 15:1946-1965. [PMID: 35338590 PMCID: PMC9249334 DOI: 10.1111/1751-7915.14024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 02/09/2022] [Accepted: 02/11/2022] [Indexed: 12/04/2022] Open
Abstract
Hydrogen is a clean alternative to fossil fuels. It has applications for electricity generation and transportation and is used for the manufacturing of ammonia and steel. However, today, H2 is almost exclusively produced from coal and natural gas. As such, methods to produce H2 that do not use fossil fuels need to be developed and adopted. The biological manufacturing of H2 may be one promising solution as this process is clean and renewable. Hydrogen is produced biologically via enzymes called hydrogenases. There are three classes of hydrogenases namely [FeFe], [NiFe] and [Fe] hydrogenases. The [FeFe] hydrogenase HydA1 from the model unicellular algae Chlamydomonas reinhardtii has been studied extensively and belongs to the A1 subclass of [FeFe] hydrogenases that have the highest turnover frequencies amongst hydrogenases (21,000 ± 12,000 H2 s−1 for CaHydA from Clostridium acetobutyliticum). Yet to date, limitations in C. reinhardtii H2 production pathways have hampered commercial scale implementation, in part due to O2 sensitivity of hydrogenases and competing metabolic pathways, resulting in low H2 production efficiency. Here, we describe key processes in the biogenesis of HydA1 and H2 production pathways in C. reinhardtii. We also summarize recent advancements of algal H2 production using synthetic biology and describe valuable tools such as high‐throughput screening (HTS) assays to accelerate the process of engineering algae for commercial biological H2 production.
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Affiliation(s)
- Samuel J King
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ante Jerkovic
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Louise J Brown
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Kerstin Petroll
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Robert D Willows
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
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23
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Zhou Q, Wang C, Yamamoto H, Shikanai T. PTOX-dependent safety valve does not oxidize P700 during photosynthetic induction in the Arabidopsis pgr5 mutant. PLANT PHYSIOLOGY 2022; 188:1264-1276. [PMID: 34792607 PMCID: PMC8825263 DOI: 10.1093/plphys/kiab541] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 10/15/2021] [Indexed: 05/19/2023]
Abstract
Plastid terminal oxidase (PTOX) accepts electrons from plastoquinol to reduce molecular oxygen to water. We introduced the gene encoding Chlamydomonas reinhardtii (Cr)PTOX2 into the Arabidopsis (Arabidopsis thaliana) wild-type (WT) and proton gradient regulation5 (pgr5) mutant defective in cyclic electron transport around photosystem I (PSI). The accumulation of CrPTOX2 only mildly affected photosynthetic electron transport in the WT background during steady-state photosynthesis but partly complemented the induction of nonphotochemical quenching (NPQ) in the pgr5 background. During the induction of photosynthesis by actinic light (AL) of 130 µmol photons m-2 s-1, the high level of PSII yield (Y(II)) was induced immediately after the onset of AL in WT plants accumulating CrPTOX2. NPQ was more rapidly induced in the transgenic plants than in WT plants. P700 was also oxidized immediately after the onset of AL. Although CrPTOX2 does not directly induce a proton concentration gradient (ΔpH) across the thylakoid membrane, the coupled reaction of PSII generated ΔpH to induce NPQ and the downregulation of the cytochrome b6f complex. Rapid induction of Y(II) and NPQ was also observed in the pgr5 plants accumulating CrPTOX2. In contrast to the WT background, P700 was not oxidized in the pgr5 background. Although the thylakoid lumen was acidified by CrPTOX2, PGR5 was essential for oxidizing P700. In addition to acidification of the thylakoid lumen to downregulate the cytochrome b6f complex (donor-side regulation), PGR5 may be required for draining electrons from PSI by transferring them to the plastoquinone pool. We propose a reevaluation of the contribution of this acceptor-side regulation by PGR5 in the photoprotection of PSI.
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Affiliation(s)
- Qi Zhou
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Caijuan Wang
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Hiroshi Yamamoto
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Author for communication:
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Electron transfer via cytochrome b6f complex displays sensitivity to Antimycin A upon STT7 kinase activation. Biochem J 2022; 479:111-127. [PMID: 34981811 DOI: 10.1042/bcj20210802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/23/2021] [Accepted: 01/04/2022] [Indexed: 11/17/2022]
Abstract
The cytochrome b6f complex (b6f) has been initially considered as the ferredoxin-plastoquinone reductase (FQR) during cyclic electron flow (CEF) with photosystem I that is inhibited by antimycin A (AA). The binding of AA to the b6f Qi-site is aggravated by heme-ci, which challenged the FQR function of b6f during CEF. Alternative models suggest that PROTON GRADIENT REGULATION5 (PGR5) is involved in a b6f-independent, AA-sensitive FQR. Here, we show in Chlamydomonas reinhardtii that the b6f is conditionally inhibited by AA in vivo and that the inhibition did not require PGR5. Instead, activation of the STT7 kinase upon anaerobic treatment induced the AA sensitivity of b6f which was absent in stt7-1. However, a lock in State 2 due to persisting phosphorylation in the phosphatase double mutant pph1;pbcp did not increase AA sensitivity of electron transfer. The latter required a redox poise, supporting the view that state transitions and CEF are not coercively coupled. This suggests that the b6f-interacting kinase is required for structure-function modulation of the Qi-site under CEF favoring conditions. We propose that PGR5 and STT7 independently sustain AA-sensitive FQR activity of the b6f. Accordingly, PGR5-mediated electron injection into an STT7-modulated Qi-site drives a Mitchellian Q cycle in CEF conditions.
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25
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The Assembly of Super-Complexes in the Plant Chloroplast. Biomolecules 2021; 11:biom11121839. [PMID: 34944483 PMCID: PMC8699064 DOI: 10.3390/biom11121839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 11/17/2022] Open
Abstract
Increasing evidence has revealed that the enzymes of several biological pathways assemble into larger supramolecular structures called super-complexes. Indeed, those such as association of the mitochondrial respiratory chain complexes play an essential role in respiratory activity and promote metabolic fitness. Dynamically assembled super-complexes are able to alternate between participating in large complexes and existing in a free state. However, the functional significance of the super-complexes is not entirely clear. It has been proposed that the organization of respiratory enzymes into super-complexes could reduce oxidative damage and increase metabolism efficiency. There are several protein complexes that have been revealed in the plant chloroplast, yet little research has been focused on the formation of super-complexes in this organelle. The photosystem I and light-harvesting complex I super-complex’s structure suggests that energy absorbed by light-harvesting complex I could be efficiently transferred to the PSI core by avoiding concentration quenching. Here, we will discuss in detail core complexes of photosystem I and II, the chloroplast ATPase the chloroplast electron transport chain, the Calvin–Benson cycle and a plastid localized purinosome. In addition, we will also describe the methods to identify these complexes.
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Couso I, Smythers AL, Ford MM, Umen JG, Crespo JL, Hicks LM. Inositol polyphosphates and target of rapamycin kinase signalling govern photosystem II protein phosphorylation and photosynthetic function under light stress in Chlamydomonas. THE NEW PHYTOLOGIST 2021; 232:2011-2025. [PMID: 34529857 DOI: 10.1111/nph.17741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 09/09/2021] [Indexed: 05/28/2023]
Abstract
Stress and nutrient availability influence cell proliferation through complex intracellular signalling networks. In a previous study it was found that pyro-inositol polyphosphates (InsP7 and InsP8 ) produced by VIP1 kinase, and target of rapamycin (TOR) kinase signalling interacted synergistically to control cell growth and lipid metabolism in the green alga Chlamydomonas reinhardtii. However, the relationship between InsPs and TOR was not completely elucidated. We used an in vivo assay for TOR activity together with global proteomic and phosphoproteomic analyses to assess differences between wild-type and vip1-1 in the presence and absence of rapamycin. We found that TOR signalling is more severely affected by the inhibitor rapamycin in a vip1-1 mutant compared with wild-type, indicating that InsP7 and InsP8 produced by VIP1 act independently but also coordinately with TOR. Additionally, among hundreds of differentially phosphorylated peptides detected, an enrichment for photosynthesis-related proteins was observed, particularly photosystem II proteins. The significance of these results was underscored by the finding that vip1-1 strains show multiple defects in photosynthetic physiology that were exacerbated under high light conditions. These results suggest a novel role for inositol pyrophosphates and TOR signalling in coordinating photosystem phosphorylation patterns in Chlamydomonas cells in response to light stress and possibly other stresses.
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Affiliation(s)
- Inmaculada Couso
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla, Avda. Américo Vespucio, 49, Sevilla, 41092, Spain
| | - Amanda L Smythers
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Megan M Ford
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - James G Umen
- Donald Danforth Plant Science Center, St Louis, MO, 63132, USA
| | - José L Crespo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla, Avda. Américo Vespucio, 49, Sevilla, 41092, Spain
| | - Leslie M Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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Nagy V, Podmaniczki A, Vidal-Meireles A, Kuntam S, Herman É, Kovács L, Tóth D, Scoma A, Tóth SZ. Thin cell layer cultures of Chlamydomonas reinhardtii L159I-N230Y, pgrl1 and pgr5 mutants perform enhanced hydrogen production at sunlight intensity. BIORESOURCE TECHNOLOGY 2021; 333:125217. [PMID: 33951580 DOI: 10.1016/j.biortech.2021.125217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 05/27/2023]
Abstract
Photobiological hydrogen (H2) production is a promising renewable energy source. HydA hydrogenases of green algae are efficient but O2-sensitive and compete for electrons with CO2-fixation. Recently, we established a photoautotrophic H2 production system based on anaerobic induction, where the Calvin-Benson cycle is inactive and O2 scavenged by an absorbent. Here, we employed thin layer cultures, resulting in a three-fold increase in H2 production relative to bulk CC-124 cultures (50 µg chlorophyll/ml, 350 µmol photons m-2 s-1). Productivity was maintained when increasing the light intensity to 1000 µmol photons m-2s-1 and the cell density to 150 µg chlorophyll/ml. Remarkably, the L159I-N230Y photosystem II mutant and the pgrl1 photosystem I cyclic electron transport mutant produced 50% more H2 than CC-124, while the pgr5 mutant generated 250% more (1.2 ml H2/ml culture in six days). The photosynthetic apparatus of the pgr5 mutant and its in vitro HydA activity remained remarkably stable.
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Affiliation(s)
- Valéria Nagy
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Anna Podmaniczki
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary; Doctoral School of Biology, University of Szeged, Közép fasor 52, H-6722 Szeged, Hungary
| | - André Vidal-Meireles
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Soujanya Kuntam
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Éva Herman
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Dávid Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary; Doctoral School of Biology, University of Szeged, Közép fasor 52, H-6722 Szeged, Hungary
| | - Alberto Scoma
- Engineered Microbial Systems Laboratory (EMS-Lab), Department of Biological and Chemical Engineering, Aarhus University, Hangøvej 2, 8200 Aarhus, Denmark
| | - Szilvia Z Tóth
- Institute of Plant Biology, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary.
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PGRL2 triggers degradation of PGR5 in the absence of PGRL1. Nat Commun 2021; 12:3941. [PMID: 34168134 PMCID: PMC8225790 DOI: 10.1038/s41467-021-24107-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 06/01/2021] [Indexed: 12/01/2022] Open
Abstract
In plants, inactivation of either of the thylakoid proteins PGR5 and PGRL1 impairs cyclic electron flow (CEF) around photosystem I. Because PGR5 is unstable in the absence of the redox-active PGRL1, but not vice versa, PGRL1 is thought to be essential for CEF. However, we show here that inactivation of PGRL2, a distant homolog of PGRL1, relieves the need for PGRL1 itself. Conversely, high levels of PGRL2 destabilize PGR5 even when PGRL1 is present. In the absence of both PGRL1 and PGRL2, PGR5 alters thylakoid electron flow and impairs plant growth. Consequently, PGR5 can operate in CEF on its own, and is the target of the CEF inhibitor antimycin A, but its activity must be modulated by PGRL1. We conclude that PGRL1 channels PGR5 activity, and that PGRL2 triggers the degradation of PGR5 when the latter cannot productively interact with PGRL1. It is currently thought that the thylakoid proteins PGRL1 and PGR5 form a complex to mediate cyclic electron flow (CEF) around photosystem I. Here the authors show that CEF can in fact be mediated by PGR5 alone and that PGRL1 and the homologous PGRL2 modify the process by modulating PGR5 activity and stability.
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Shimakawa G, Hanawa H, Wada S, Hanke GT, Matsuda Y, Miyake C. Physiological Roles of Flavodiiron Proteins and Photorespiration in the Liverwort Marchantia polymorpha. FRONTIERS IN PLANT SCIENCE 2021; 12:668805. [PMID: 34489990 PMCID: PMC8418088 DOI: 10.3389/fpls.2021.668805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/30/2021] [Indexed: 05/19/2023]
Abstract
Against the potential risk in oxygenic photosynthesis, that is, the generation of reactive oxygen species, photosynthetic electron transport needs to be regulated in response to environmental fluctuations. One of the most important regulations is keeping the reaction center chlorophyll (P700) of photosystem I in its oxidized form in excess light conditions. The oxidation of P700 is supported by dissipating excess electrons safely to O2, and we previously found that the molecular mechanism of the alternative electron sink is changed from flavodiiron proteins (FLV) to photorespiration in the evolutionary history from cyanobacteria to plants. However, the overall picture of the regulation of photosynthetic electron transport is still not clear in bryophytes, the evolutionary intermediates. Here, we investigated the physiological roles of FLV and photorespiration for P700 oxidation in the liverwort Marchantia polymorpha by using the mutants deficient in FLV (flv1) at different O2 partial pressures. The effective quantum yield of photosystem II significantly decreased at 2kPa O2 in flv1, indicating that photorespiration functions as the electron sink. Nevertheless, it was clear from the phenotype of flv1 that FLV was dominant for P700 oxidation in M. polymorpha. These data suggested that photorespiration has yet not replaced FLV in functioning for P700 oxidation in the basal land plant probably because of the lower contribution to lumen acidification, compared with FLV, as reflected in the results of electrochromic shift analysis.
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Affiliation(s)
- Ginga Shimakawa
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Research Center for Solar Energy Chemistry, Osaka University, Suita, Japan
- Department of Biosciences, School of Biological and Environmental Sciences, Kwansei-Gakuin University, Nishinomiya, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
| | - Hitomi Hanawa
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Shinya Wada
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
| | - Guy T. Hanke
- School of Biochemistry and Chemistry, Queen Mary University of London, London, United Kingdom
| | - Yusuke Matsuda
- Department of Biosciences, School of Biological and Environmental Sciences, Kwansei-Gakuin University, Nishinomiya, Japan
| | - Chikahiro Miyake
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
- *Correspondence: Chikahiro Miyake,
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30
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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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31
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Chouhan N, Devadasu E, Yadav RM, Subramanyam R. Autophagy Induced Accumulation of Lipids in pgrl1 and pgr5 of Chlamydomonas reinhardtii Under High Light. FRONTIERS IN PLANT SCIENCE 2021; 12:752634. [PMID: 35145528 PMCID: PMC8821104 DOI: 10.3389/fpls.2021.752634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 12/20/2021] [Indexed: 05/03/2023]
Abstract
Chlamydomonas (C.) reinhardtii is a potential microalga for lipid production. Autophagy-triggered lipid metabolism in microalgae has not being studied so far from a mutant of proton gradient regulation 1 like (PGRL1) and proton gradient regulation 5 (PGR5). In this study, C. reinhardtii cells (wild-type CC124 and cyclic electron transport dependant mutants pgrl1 and pgr5) were grown photoheterotrophically in high light 500 μmol photons m-2 s-1, where pgr5 growth was retarded due to an increase in reactive oxygen species (ROS). The lipid contents were increased; however, carbohydrate content was decreased in pgr5. Further, the Nile Red (NR) fluorescence shows many lipid bodies in pgr5 cells under high light. Similarly, the electron micrographs show that large vacuoles were formed in high light stress despite the grana stacks structure. We also observed increased production of reactive oxygen species, which could be one reason the cells underwent autophagy. Further, a significant increase of autophagy ATG8 and detections of ATG8-PE protein was noticed in pgr5, a hallmark characteristic for autophagy formation. Consequently, the triacylglycerol (TAG) content was increased due to diacylglycerol acyltransferases (DGAT) and phospholipid diacylglycerol acyl-transference (PDAT) enzymes' expression, especially in pgr5. Here the TAG synthesis would have been obtained from degraded membrane lipids in pgr5. Additionally, mono, polyunsaturated, and saturated fatty acids were identified more in the high light condition. Our study shows that the increased light induces the reactive oxygen species, which leads to autophagy and TAG accumulation. Therefore, the enhanced accumulation of TAGs can be used as feedstock for biodiesel production and aqua feed.
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PGR5 is required for efficient Q cycle in the cytochrome b6f complex during cyclic electron flow. Biochem J 2020; 477:1631-1650. [PMID: 32267468 DOI: 10.1042/bcj20190914] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/23/2020] [Accepted: 04/07/2020] [Indexed: 01/07/2023]
Abstract
Proton gradient regulation 5 (PGR5) is involved in the control of photosynthetic electron transfer, but its mechanistic role is not yet clear. Several models have been proposed to explain phenotypes such as a diminished steady-state proton motive force (pmf) and increased photodamage of photosystem I (PSI). Playing a regulatory role in cyclic electron flow (CEF) around PSI, PGR5 contributes indirectly to PSI protection by enhancing photosynthetic control, which is a pH-dependent down-regulation of electron transfer at the cytochrome b6f complex (b6f). Here, we re-evaluated the role of PGR5 in the green alga Chlamydomonas reinhardtii and conclude that pgr5 possesses a dysfunctional b6f. Our data indicate that the b6f low-potential chain redox activity likely operated in two distinct modes - via the canonical Q cycle during linear electron flow and via an alternative Q cycle during CEF, which allowed efficient oxidation of the low-potential chain in the WT b6f. A switch between the two Q cycle modes was dependent on PGR5 and relied on unknown stromal electron carrier(s), which were a general requirement for b6f activity. In CEF-favoring conditions, the electron transfer bottleneck in pgr5 was the b6f, in which insufficient low-potential chain redox tuning might account for the mutant pmf phenotype. By attributing a ferredoxin-plastoquinone reductase activity to the b6f and investigating a PGR5 cysteine mutant, a current model of CEF is challenged.
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Yadav RM, Aslam SM, Madireddi SK, Chouhan N, Subramanyam R. Role of cyclic electron transport mutations pgrl1 and pgr5 in acclimation process to high light in Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2020; 146:247-258. [PMID: 32350701 DOI: 10.1007/s11120-020-00751-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 04/15/2020] [Indexed: 05/19/2023]
Abstract
Light is crucial for photosynthesis, but the amount of light that exceeds an organism's assimilation efficacy can lead to photo-oxidative damage and even cell death. In Chlamydomonas (C). reinhardtii cyclic electron flow (CEF) is very important for the elicitation of non-photochemical quenching (NPQ) by controlling the acidification of thylakoid lumen. This process requires the cooperation of proton gradient regulation (PGR) proteins, PGRL1 and PGR5. Here, we compared the growth pattern and photosynthetic activity between wild type (137c, t222+) and mutants impaired in CEF (pgrl1 and pgr5) under photoautotrophic and photoheterotrophic conditions. We have observed the discriminative expression of NPQ in the mutants impaired in CEF of pgrl1 and pgr5. The results obtained from the mutants showed reduced cell growth and density, Chl a/b ratio, fluorescence, electron transport rate, and yield of photosystem (PS)II. These mutants have reduced capability to develop a strong NPQ indicating that the role of CEF is very crucial for photoprotection. Moreover, the CEF mutant exhibits increased photosensitivity compared with the wild type. Therefore, we suggest that besides NPQ, the fraction of non-regulated non-photochemical energy loss (NO) also plays a crucial role during high light acclimation despite a low growth rate. This low NPQ rate may be due to less influx of protons coming from the CEF in cases of pgrl1 and pgr5 mutants. These results are discussed in terms of the relative photoprotective benefit, related to the thermal dissipation of excess light in photoautotrophic and photoheterotrophic conditions.
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Affiliation(s)
- Ranay Mohan Yadav
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana, 500046, India
| | - Sabit Mohammad Aslam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana, 500046, India
| | - Sai Kiran Madireddi
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana, 500046, India
| | - Nisha Chouhan
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana, 500046, India
| | - Rajagopal Subramanyam
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana, 500046, India.
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34
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A fluorescence-based approach to screen for productive chemically mutagenized strains of Desmodesmus armatus. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.102028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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35
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Over Expression of the Cyanobacterial Pgr5-Homologue Leads to Pseudoreversion in a Gene Coding for a Putative Esterase in Synechocystis 6803. Life (Basel) 2020; 10:life10090174. [PMID: 32899164 PMCID: PMC7555055 DOI: 10.3390/life10090174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 01/13/2023] Open
Abstract
Pgr5 proteins play a major direct role in cyclic electron flow paths in plants and eukaryotic phytoplankton. The genomes of many cyanobacterial species code for Pgr5-like proteins but their function is still uncertain. Here, we present evidence that supports a link between the Synechocystis sp. PCC6803 Pgr5-like protein and the regulation of intracellular redox balance. The knockout strain, pgr5KO, did not display substantial phenotypic response under our experimental conditions, confirming results obtained in earlier studies. However, the overexpression strain, pgr5OE, accumulated 2.5-fold more chlorophyll than the wild type and displayed increased content of photosystems matching the chlorophyll increase. As a result, electron transfer rates through the photosynthetic apparatus of pgr5OE increased, as did the amount of energy stored as glycogen. While, under photoautotrophic conditions, this metabolic difference had only minor effects, under mixotrophic conditions, pgr5OE cultures collapsed. Interestingly, this specific phenotype of pgr5OE mutants displayed a tendency for reverting, and cultures which previously collapsed in the presence of glucose were now able to survive. DNA sequencing of a pgr5OE strain revealed a second site suppression mutation in slr1916, a putative esterase associated with redox regulation. The phenotype of the slr1916 knockout is very similar to that of the strain reported here and to that of the pmgA regulator knockout. These data demonstrate that, in Synechocystis 6803, there is strong selection against overexpression of the Pgr5-like protein. The pseudoreversion event in a gene involved in redox regulation suggests a connection of the Pgr5-like protein to this network.
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Yamamoto H, Shikanai T. Does the Arabidopsis proton gradient regulation5 Mutant Leak Protons from the Thylakoid Membrane? PLANT PHYSIOLOGY 2020; 184:421-427. [PMID: 32636340 PMCID: PMC7479887 DOI: 10.1104/pp.20.00850] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 06/27/2020] [Indexed: 05/19/2023]
Abstract
Despite generating an obvious mutant phenotype, whether the Arabidopsis (Arabidopsis thaliana) proton gradient regulation5 (pgr5) mutation influences cyclic electron transport (CET) around PSI is a topic of debate. Results of electrochromic shift analysis show that proton conductivity across the thylakoid membrane (g H +) in the pgr5 mutant is enhanced at high light intensity. Given this observation, PGR5 was proposed to regulate ATP synthase activity rather than mediating CET. The originally reported pgr5 phenotype reflects a smaller proton motive force (pmf) and could be explained by this H+ leakage model. In this study, we genetically reexamined the high-g H + phenotype of the pgr5 mutant. Transgenic lines in which flavodiiron protein-dependent pseudo-CET replaced PGR5-dependent CET had wild-type levels of g H +, suggesting that the high-g H + phenotype in pgr5 plants is caused secondarily by the low pmf. The pgr1 mutant shows a similar reduction in pmf because of enhanced sensitivity of its cytochrome b 6 f complex to lumenal acidification. In contrast to the pgr5 mutant, g H + was lower in the pgr1 mutant than in the wild type. In the pgr1 pgr5 double mutants, g H + was intermediate to g H + values of the respective single mutants. It is unlikely that g H + is upregulated simply in response to a low pmf. We did not observe uncoupling of the thylakoid membrane in the pgr5 mutant upon monitoring the quenching of 9-aminoacridine fluorescence. We conclude that the g H + parameter may be influenced by other factors not related to the H+ leakage through ATP synthase. It is unlikely that the pgr5 mutant leaks protons from the thylakoid membrane.
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Affiliation(s)
- Hiroshi Yamamoto
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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Wolf BC, Isaacson T, Tiwari V, Dangoor I, Mufkadi S, Danon A. Redox regulation of PGRL1 at the onset of low light intensity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:715-725. [PMID: 32259361 DOI: 10.1111/tpj.14764] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 03/16/2020] [Accepted: 03/24/2020] [Indexed: 05/11/2023]
Abstract
PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE1 (PGRL1) regulates photosystem I cyclic electron flow which transiently activates non-photochemical quenching at the onset of light. Here, we show that a disulfide-based mechanism of PGRL1 regulated this process in vivo at the onset of low light levels. We found that PGRL1 regulation depended on active formation of key regulatory disulfides in the dark, and that PGR5 was required for this activity. The disulfide state of PGRL1 was modulated in plants by counteracting reductive and oxidative components and reached a balanced state that depended on the light level. We propose that the redox regulation of PGRL1 fine-tunes a timely activation of photosynthesis at the onset of low light.
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Affiliation(s)
- Bat-Chen Wolf
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Tal Isaacson
- Newe Ya'ar Research Center, Agricultural Research Organization, Ramat Yishay, 30095, Israel
| | - Vivekanand Tiwari
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Inbal Dangoor
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Sapir Mufkadi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Avihai Danon
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
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Tazoe Y, Ishikawa N, Shikanai T, Ishiyama K, Takagi D, Makino A, Sato F, Endo T. Overproduction of PGR5 enhances the electron sink downstream of photosystem I in a C 4 plant, Flaveria bidentis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:814-823. [PMID: 32314445 DOI: 10.1111/tpj.14774] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 03/31/2020] [Accepted: 04/07/2020] [Indexed: 05/25/2023]
Abstract
C4 plants can fix CO2 efficiently using CO2 -concentrating mechanisms (CCMs), but they require additional ATP. To supply the additional ATP, C4 plants operate at higher rates of cyclic electron transport around photosystem I (PSI), in which electrons are transferred from ferredoxin to plastoquinone. Recently, it has been reported that the NAD(P)H dehydrogenase-like complex (NDH) accumulated in the thylakoid membrane in leaves of C4 plants, making it a candidate for the additional synthesis of ATP used in the CCM. In addition, C4 plants have higher levels of PROTON GRADIENT REGULATION 5 (PGR5) expression, but it has been unknown how PGR5 functions in C4 photosynthesis. In this study, PGR5 was overexpressed in a C4 dicot, Flaveria bidentis. In PGR5-overproducing (OP) lines, PGR5 levels were 2.3- to 3.0-fold greater compared with wild-type plants. PGR5-like PHOTOSYNTHETIC PHENOTYPE 1 (PGRL1), which cooperates with PGR5, increased with PGR5. A spectroscopic analysis indicated that in the PGR5-OP lines, the acceptor side limitation of PSI was reduced in response to a rapid increase in photon flux density. Although it did not affect CO2 assimilation, the overproduction of PGR5 contributed to an enhanced electron sink downstream of PSI.
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Affiliation(s)
- Youshi Tazoe
- Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, 606-8052, Japan
- Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, 980-0845, Japan
- CREST, JST, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan
- Faculty of Agro-Food Science, Niigata Agro-Food University, Tainai, Niigata, 959-2702, Japan
| | - Noriko Ishikawa
- Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, 606-8052, Japan
| | - Toshiharu Shikanai
- CREST, JST, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan
- Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8052, Japan
| | - Keiki Ishiyama
- Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, 980-0845, Japan
| | - Daisuke Takagi
- Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, 980-0845, Japan
- Faculty of Agriculture, Setsunan University, Hirakata, Osaka, 573-0101, Japan
| | - Amane Makino
- Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, 980-0845, Japan
- CREST, JST, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan
| | - Fumihiko Sato
- Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, 606-8052, Japan
| | - Tsuyoshi Endo
- Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, 606-8052, Japan
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Redekop P, Rothhausen N, Rothhausen N, Melzer M, Mosebach L, Dülger E, Bovdilova A, Caffarri S, Hippler M, Jahns P. PsbS contributes to photoprotection in Chlamydomonas reinhardtii independently of energy dissipation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148183. [DOI: 10.1016/j.bbabio.2020.148183] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 02/19/2020] [Accepted: 03/09/2020] [Indexed: 02/06/2023]
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Wang Y, Li X, Liu N, Wei S, Wang J, Qin F, Suo B. The iTRAQ-based chloroplast proteomic analysis of Triticum aestivum L. leaves subjected to drought stress and 5-aminolevulinic acid alleviation reveals several proteins involved in the protection of photosynthesis. BMC PLANT BIOLOGY 2020; 20:96. [PMID: 32131734 PMCID: PMC7057492 DOI: 10.1186/s12870-020-2297-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 02/20/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUNDS The perturbance of chloroplast proteins is a major cause of photosynthesis inhibition under drought stress. The exogenous application of 5-aminolevulinic acid (ALA) mitigates the damage caused by drought stress, protecting plant growth and development, but the regulatory mechanism behind this process remains obscure. RESULTS Wheat seedlings were drought treated, and the iTRAQ-based proteomic approach was employed to assess the difference in chloroplast protein content caused by exogenous ALA. A total of 9499 peptides, which could be classified into 2442 protein groups, were identified with ≤0.01 FDR. Moreover, the contents of 87 chloroplast proteins was changed by drought stress alone compared to that of the drought-free control, while the contents of 469 was changed by exogenous ALA application under drought stress compared to that of drought stress alone. The Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results suggested that the ALA pretreatment adjusted some biological pathways, such as metabolic pathways and pathways involved in photosynthesis and ribosomes, to enhance the drought resistance of chloroplasts. Furthermore, the drought-promoted H2O2 accumulation and O2- production in chloroplasts were alleviated by the exogenous pretreatment of ALA, while peroxidase (POD) and glutathione peroxidase (GPX) activities were upregulated, which agreed with the chloroplast proteomic data. We suggested that ALA promoted reactive oxygen species (ROS) scavenging in chloroplasts by regulating enzymatic processes. CONCLUSIONS Our results from chloroplast proteomics extend the understanding of the mechanisms employed by exogenous ALA to defend against drought stress in wheat.
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Affiliation(s)
- Yuexia Wang
- College of Life Sciences, Henan Agricultural University, No. 63, Nongye Rd., Zhengzhou, 450002 Henan Province China
| | - Xiaoyan Li
- College of Life Sciences, Henan Agricultural University, No. 63, Nongye Rd., Zhengzhou, 450002 Henan Province China
| | - Nana Liu
- College of Science, China Agricultural University, Beijing, 100193 China
| | - Shimei Wei
- College of Life Sciences, Henan Agricultural University, No. 63, Nongye Rd., Zhengzhou, 450002 Henan Province China
| | - Jianan Wang
- College of Life Sciences, Henan Agricultural University, No. 63, Nongye Rd., Zhengzhou, 450002 Henan Province China
| | - Fujun Qin
- Department of Pathology, University of Virginia, Charlottesville, VA 22908 USA
| | - Biao Suo
- College of Food Science and Technology, Henan Agricultural University, No. 63, Nongye Rd., Zhengzhou, 450002 Henan Province China
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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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Rochaix JD. The Dynamics of the Photosynthetic Apparatus in Algae. PHOTOSYNTHESIS IN ALGAE: BIOCHEMICAL AND PHYSIOLOGICAL MECHANISMS 2020. [DOI: 10.1007/978-3-030-33397-3_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Cecchin M, Marcolungo L, Rossato M, Girolomoni L, Cosentino E, Cuine S, Li‐Beisson Y, Delledonne M, Ballottari M. Chlorella vulgaris genome assembly and annotation reveals the molecular basis for metabolic acclimation to high light conditions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:1289-1305. [PMID: 31437318 PMCID: PMC6972661 DOI: 10.1111/tpj.14508] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 05/05/2023]
Abstract
Chlorella vulgaris is a fast-growing fresh-water microalga cultivated on the industrial scale for applications ranging from food to biofuel production. To advance our understanding of its biology and to establish genetics tools for biotechnological manipulation, we sequenced the nuclear and organelle genomes of Chlorella vulgaris 211/11P by combining next generation sequencing and optical mapping of isolated DNA molecules. This hybrid approach allowed us to assemble the nuclear genome in 14 pseudo-molecules with an N50 of 2.8 Mb and 98.9% of scaffolded genome. The integration of RNA-seq data obtained at two different irradiances of growth (high light, HL versus low light, LL) enabled us to identify 10 724 nuclear genes, coding for 11 082 transcripts. Moreover, 121 and 48 genes, respectively, were found in the chloroplast and mitochondrial genome. Functional annotation and expression analysis of nuclear, chloroplast and mitochondrial genome sequences revealed particular features of Chlorella vulgaris. Evidence of horizontal gene transfers from chloroplast to mitochondrial genome was observed. Furthermore, comparative transcriptomic analyses of LL versus HL provided insights into the molecular basis for metabolic rearrangement under HL versus LL conditions leading to enhanced de novo fatty acid biosynthesis and triacylglycerol accumulation. The occurrence of a cytosolic fatty acid biosynthetic pathway could be predicted and its upregulation upon HL exposure was observed, consistent with the increased lipid amount under HL conditions. These data provide a rich genetic resource for future genome editing studies, and potential targets for biotechnological manipulation of Chlorella vulgaris or other microalgae species to improve biomass and lipid productivity.
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Affiliation(s)
- Michela Cecchin
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Luca Marcolungo
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Marzia Rossato
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Laura Girolomoni
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Emanuela Cosentino
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Stephan Cuine
- Institute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265Aix‐Marseille UniversityCEACNRSCEA CadaracheSaint‐Paul‐lez DuranceF‐13108France
| | - Yonghua Li‐Beisson
- Institute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265Aix‐Marseille UniversityCEACNRSCEA CadaracheSaint‐Paul‐lez DuranceF‐13108France
| | - Massimo Delledonne
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Matteo Ballottari
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
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Dann M, Leister D. Evidence that cyanobacterial Sll1217 functions analogously to PGRL1 in enhancing PGR5-dependent cyclic electron flow. Nat Commun 2019; 10:5299. [PMID: 31757966 PMCID: PMC6876563 DOI: 10.1038/s41467-019-13223-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/29/2019] [Indexed: 11/19/2022] Open
Abstract
In plants and cyanobacteria, the PGR5 protein contributes to cyclic electron flow around photosystem I. In plants, PGR5 interacts with PGRL1 during cyclic electron flow, but cyanobacteria appear to lack PGRL1 proteins. We have heterologously expressed the PGR5 and PGRL1 proteins from the plant Arabidopsis in various genetic backgrounds in the cyanobacterium Synechocystis. Our results show that plant PGR5 suffices to re-establish cyanobacterial cyclic electron flow (CEF), albeit less efficiently than the cyanobacterial PGR5 or the plant PGR5 and PGRL1 proteins together. A mutation that inactivates Arabidopsis PGR5 destabilises the protein in Synechocystis. Furthermore, the Synechocystis protein Sll1217, which exhibits weak sequence similarity with PGRL1, physically interacts with both plant and cyanobacterial PGR5 proteins, and stimulates CEF in Synechocystis. Therefore, Sll1217 partially acts as a PGRL1 analogue, the mode of action of PGR5 and PGRL1/Sll1217 proteins is similar in cyanobacteria and plants, and PGRL1 could have evolved from a cyanobacterial ancestor.
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Affiliation(s)
- Marcel Dann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University Munich, Großhaderner Str. 2, D-82152, Planegg-Martinsried, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians University Munich, Großhaderner Str. 2, D-82152, Planegg-Martinsried, Germany.
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Ben-Zvi O, Dafni E, Feldman Y, Yacoby I. Re-routing photosynthetic energy for continuous hydrogen production in vivo. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:266. [PMID: 31737095 PMCID: PMC6844042 DOI: 10.1186/s13068-019-1608-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 11/04/2019] [Indexed: 05/09/2023]
Abstract
BACKGROUND Hydrogen is considered a promising energy vector that can be produced from sustainable resources such as sunlight and water. In green algae, such as Chlamydomonas reinhardtii, photoproduction of hydrogen is catalyzed by the enzyme [FeFe]-hydrogenase (HydA). Although highly efficient, this process is transitory and thought to serve as a release valve for excess reducing power. Up to date, prolonged production of hydrogen was achieved by the deprivation of either nutrients or light, thus, hindering the full potential of photosynthetic hydrogen production. Previously we showed that the enzyme superoxide dismutase (SOD) can enhance HydA activity in vitro, specifically when tied together to a fusion protein. RESULTS In this work, we explored the in vivo hydrogen production phenotype of HydA-SOD fusion. We found a sustained hydrogen production, which is dependent on linear electron flow, although other pathways feed it as well. In addition, other characteristics such as slower growth and oxygen production were also observed in Hyd-SOD-expressing algae. CONCLUSIONS The Hyd-SOD fusion manages to outcompete the Calvin-Benson cycle, allowing sustained hydrogen production for up to 14 days in non-limiting conditions.
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Affiliation(s)
- Oren Ben-Zvi
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel
| | - Eyal Dafni
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel
| | - Yael Feldman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel
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Scholz M, Gäbelein P, Xue H, Mosebach L, Bergner SV, Hippler M. Light-dependent N-terminal phosphorylation of LHCSR3 and LHCB4 are interlinked in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 99:877-894. [PMID: 31033075 PMCID: PMC6851877 DOI: 10.1111/tpj.14368] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 03/15/2019] [Accepted: 04/16/2019] [Indexed: 05/08/2023]
Abstract
Phosphorylation dynamics of LHCSR3 were investigated in Chlamydomonas reinhardtii by quantitative proteomics and genetic engineering. LHCSR3 protein expression and phosphorylation were induced in high light. Our data revealed synergistic and dynamic N-terminal LHCSR3 phosphorylation. Phosphorylated and nonphosphorylated LHCSR3 associated with PSII-LHCII supercomplexes. The phosphorylation status of LHCB4 was closely linked to the phosphorylation of multiple sites at the N-terminus of LHCSR3, indicating that LHCSR3 phosphorylation may operate as a molecular switch modulating LHCB4 phosphorylation, which in turn is important for PSII-LHCII disassembly. Notably, LHCSR3 phosphorylation diminished under prolonged high light, which coincided with onset of CEF. Hierarchical clustering of significantly altered proteins revealed similar expression profiles of LHCSR3, CRX, and FNR. This finding indicated the existence of a functional link between LHCSR3 protein abundance and phosphorylation, photosynthetic electron flow, and the oxidative stress response.
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Affiliation(s)
- Martin Scholz
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| | - Philipp Gäbelein
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| | - Huidan Xue
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| | - Laura Mosebach
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
| | - Sonja Verena Bergner
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
- Present address:
Max Planck Institute of Molecular Plant PhysiologyAm Mühlenberg 1Potsdam‐Golm14476Germany
| | - Michael Hippler
- Institute of Plant Biology and BiotechnologyUniversity of MünsterSchlossplatz 8Münster48143Germany
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Grossman A, Sanz-Luque E, Yi H, Yang W. Building the GreenCut2 suite of proteins to unmask photosynthetic function and regulation. Microbiology (Reading) 2019; 165:697-718. [DOI: 10.1099/mic.0.000788] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Arthur Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Emanuel Sanz-Luque
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Heng Yi
- Key Laboratory of Photobiology, Institute of Botany (CAS), Beijing, PR China
- University of Chinese Academy of Sciences, Beijing, PR China
| | - Wenqiang Yang
- Key Laboratory of Photobiology, Institute of Botany (CAS), Beijing, PR China
- University of Chinese Academy of Sciences, Beijing, PR China
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48
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Alternative outlets for sustaining photosynthetic electron transport during dark-to-light transitions. Proc Natl Acad Sci U S A 2019; 116:11518-11527. [PMID: 31101712 PMCID: PMC6561286 DOI: 10.1073/pnas.1903185116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Most forms of life on Earth cannot exist without photosynthesis. Our food and atmosphere depend on it. To obtain high photosynthetic yields, light energy must be efficiently coupled to the fixation of CO2 into organic molecules. Suboptimal environmental conditions can severely impact the conversion of light energy to biomass and lead to reactive oxygen production, which in turn can cause cellular damage and loss of productivity. Hence, plants, algae, and photosynthetic bacteria have evolved a network of alternative outlets to sustain the flow of photosynthetically derived electrons. Our work is focused on the nature and integration of these outlets, which will inform a rational engineering of crop plants and algae to optimize photosynthesis and meet the increased global demand for food. Environmental stresses dramatically impact the balance between the production of photosynthetically derived energetic electrons and Calvin–Benson–Bassham cycle (CBBC) activity; an imbalance promotes accumulation of reactive oxygen species and causes cell damage. Hence, photosynthetic organisms have developed several strategies to route electrons toward alternative outlets that allow for storage or harmless dissipation of their energy. In this work, we explore the activities of three essential outlets associated with Chlamydomonas reinhardtii photosynthetic electron transport: (i) reduction of O2 to H2O through flavodiiron proteins (FLVs) and (ii) plastid terminal oxidases (PTOX) and (iii) the synthesis of starch. Real-time measurements of O2 exchange have demonstrated that FLVs immediately engage during dark-to-light transitions, allowing electron transport when the CBBC is not fully activated. Under these conditions, we quantified maximal FLV activity and its overall capacity to direct photosynthetic electrons toward O2 reduction. However, when starch synthesis is compromised, a greater proportion of the electrons is directed toward O2 reduction through both the FLVs and PTOX, suggesting an important role for starch synthesis in priming/regulating CBBC and electron transport. Moreover, partitioning energized electrons between sustainable (starch; energetic electrons are recaptured) and nonsustainable (H2O; energetic electrons are not recaptured) outlets is part of the energy management strategy of photosynthetic organisms that allows them to cope with the fluctuating conditions encountered in nature. Finally, unmasking the repertoire and control of such energetic reactions offers new directions for rational redesign and optimization of photosynthesis to satisfy global demands for food and other resources.
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Nawrocki W, Bailleul B, Cardol P, Rappaport F, Wollman FA, Joliot P. Maximal cyclic electron flow rate is independent of PGRL1 in Chlamydomonas. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:425-432. [DOI: 10.1016/j.bbabio.2019.01.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 12/08/2018] [Accepted: 01/25/2019] [Indexed: 11/30/2022]
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50
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Nawrocki WJ, Bailleul B, Picot D, Cardol P, Rappaport F, Wollman FA, Joliot P. The mechanism of cyclic electron flow. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:433-438. [PMID: 30827891 DOI: 10.1016/j.bbabio.2018.12.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 12/08/2018] [Accepted: 12/08/2018] [Indexed: 12/16/2022]
Abstract
Apart from the canonical light-driven linear electron flow (LEF) from water to CO2, numerous regulatory and alternative electron transfer pathways exist in chloroplasts. One of them is the cyclic electron flow around Photosystem I (CEF), contributing to photoprotection of both Photosystem I and II (PSI, PSII) and supplying extra ATP to fix atmospheric carbon. Nonetheless, CEF remains an enigma in the field of functional photosynthesis as we lack understanding of its pathway. Here, we address the discrepancies between functional and genetic/biochemical data in the literature and formulate novel hypotheses about the pathway and regulation of CEF based on recent structural and kinetic information.
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Affiliation(s)
- W J Nawrocki
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France; Laboratoire de Génétique et Physiologie des Microalgues, Institut de Botanique, Université de Liège, 4, Chemin de la Vallée, B-4000 Liège, Belgium.
| | - B Bailleul
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| | - D Picot
- Institut de Biologie Physico-Chimique, UMR 7099 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| | - P Cardol
- Laboratoire de Génétique et Physiologie des Microalgues, Institut de Botanique, Université de Liège, 4, Chemin de la Vallée, B-4000 Liège, Belgium
| | - F Rappaport
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| | - F-A Wollman
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
| | - P Joliot
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue P. et M. Curie, 75005 Paris, France
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