1
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Milrad Y, Mosebach L, Buchert F. Regulation of Microalgal Photosynthetic Electron Transfer. PLANTS (BASEL, SWITZERLAND) 2024; 13:2103. [PMID: 39124221 PMCID: PMC11314055 DOI: 10.3390/plants13152103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 07/24/2024] [Accepted: 07/26/2024] [Indexed: 08/12/2024]
Abstract
The global ecosystem relies on the metabolism of photosynthetic organisms, featuring the ability to harness light as an energy source. The most successful type of photosynthesis utilizes a virtually inexhaustible electron pool from water, but the driver of this oxidation, sunlight, varies on time and intensity scales of several orders of magnitude. Such rapid and steep changes in energy availability are potentially devastating for biological systems. To enable a safe and efficient light-harnessing process, photosynthetic organisms tune their light capturing, the redox connections between core complexes and auxiliary electron mediators, ion passages across the membrane, and functional coupling of energy transducing organelles. Here, microalgal species are the most diverse group, featuring both unique environmental adjustment strategies and ubiquitous protective mechanisms. In this review, we explore a selection of regulatory processes of the microalgal photosynthetic apparatus supporting smooth electron flow in variable environments.
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Affiliation(s)
- Yuval Milrad
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Laura Mosebach
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
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2
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Kim M, Cazzaniga S, Jang J, Pivato M, Kim G, Ballottari M, Jin E. Photoautotrophic cultivation of a Chlamydomonas reinhardtii mutant with zeaxanthin as the sole xanthophyll. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:41. [PMID: 38486329 PMCID: PMC10941483 DOI: 10.1186/s13068-024-02483-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 02/24/2024] [Indexed: 03/17/2024]
Abstract
BACKGROUND Photosynthetic microalgae are known for their sustainable and eco-friendly potential to convert carbon dioxide into valuable products. Nevertheless, the challenge of self-shading due to high cell density has been identified as a drawback, hampering productivity in sustainable photoautotrophic mass cultivation. To address this issue, mutants with altered pigment composition have been proposed to allow a more efficient light diffusion but further study on the role of the different pigments is still needed to correctly engineer this process. RESULTS We here investigated the Chlamydomonas reinhardtii Δzl mutant with zeaxanthin as the sole xanthophyll. The Δzl mutant displayed altered pigment composition, characterized by lower chlorophyll content, higher chlorophyll a/b ratio, and lower chlorophyll/carotenoid ratio compared to the wild type (Wt). The Δzl mutant also exhibited a significant decrease in the light-harvesting complex II/Photosystem II ratio (LHCII/PSII) and the absence of trimeric LHCIIs. This significantly affects the organization and stability of PSII supercomplexes. Consequently, the estimated functional antenna size of PSII in the Δzl mutant was approximately 60% smaller compared to that of Wt, and reduced PSII activity was evident in this mutant. Notably, the Δzl mutant showed impaired non-photochemical quenching. However, the Δzl mutant compensated by exhibiting enhanced cyclic electron flow compared to Wt, seemingly offsetting the impaired PSII functionality. Consequently, the Δzl mutant achieved significantly higher cell densities than Wt under high-light conditions. CONCLUSIONS Our findings highlight significant changes in pigment content and pigment-protein complexes in the Δzl mutant compared to Wt, resulting in an advantage for high-density photoautotrophic cultivation. This advantage is attributed to the decreased chlorophyll content of the Δzl mutant, allowing better light penetration. In addition, the accumulated zeaxanthin in the mutant could serve as an antioxidant, offering protection against reactive oxygen species generated by chlorophylls.
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Affiliation(s)
- Minjae Kim
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, 04763, Korea
| | | | - Junhwan Jang
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, 04763, Korea
| | - Matteo Pivato
- Dipartimento di Biotecnologie, Università di Verona, Verona, Italy
| | - Gueeda Kim
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, 04763, Korea
| | | | - EonSeon Jin
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, 04763, Korea.
- Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, 04763, Korea.
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3
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Zhang N, Venn B, Bailey CE, Xia M, Mattoon EM, Mühlhaus T, Zhang R. Moderate high temperature is beneficial or detrimental depending on carbon availability in the green alga Chlamydomonas reinhardtii. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:979-1003. [PMID: 37877811 DOI: 10.1093/jxb/erad405] [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: 05/21/2023] [Accepted: 10/21/2023] [Indexed: 10/26/2023]
Abstract
High temperatures impair plant growth and reduce agricultural yields, but the underlying mechanisms remain elusive. The unicellular green alga Chlamydomonas reinhardtii is an excellent model to study heat responses in photosynthetic cells due to its fast growth rate, many similarities in cellular processes to land plants, simple and sequenced genome, and ample genetic and genomics resources. Chlamydomonas grows in light by photosynthesis and with externally supplied acetate as an organic carbon source. Understanding how organic carbon sources affect heat responses is important for the algal industry but remains understudied. We cultivated wild-type Chlamydomonas under highly controlled conditions in photobioreactors at 25 °C (control), 35 °C (moderate high temperature), or 40 °C (acute high temperature) with or without constant acetate supply for 1 or 4 day. Treatment at 35 °C increased algal growth with constant acetate supply but reduced algal growth without sufficient acetate. The overlooked and dynamic effects of 35 °C could be explained by induced acetate uptake and metabolism. Heat treatment at 40 °C for more than 2 day was lethal to algal cultures with or without constant acetate supply. Our findings provide insights to understand algal heat responses and help improve thermotolerance in photosynthetic cells.
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Affiliation(s)
- Ningning Zhang
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
| | - Benedikt Venn
- Computational Systems Biology, RPTU Kaiserslautern, 67663 Kaiserslautern, Germany
| | | | - Ming Xia
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
| | - Erin M Mattoon
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
- Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, MO 63130, USA
| | - Timo Mühlhaus
- Computational Systems Biology, RPTU Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Ru Zhang
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
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4
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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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5
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Kalra I, Wang X, Zhang R, Morgan-Kiss R. High salt-induced PSI-supercomplex is associated with high CEF and attenuation of state transitions. PHOTOSYNTHESIS RESEARCH 2023; 157:65-84. [PMID: 37347385 PMCID: PMC10484818 DOI: 10.1007/s11120-023-01032-y] [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: 02/06/2023] [Accepted: 06/05/2023] [Indexed: 06/23/2023]
Abstract
While PSI-driven cyclic electron flow (CEF) and assembly of thylakoid supercomplexes have been described in model organisms like Chlamydomonas reinhardtii, open questions remain regarding their contributions to survival under long-term stress. The Antarctic halophyte, C. priscuii UWO241 (UWO241), possesses constitutive high CEF rates and a stable PSI-supercomplex as a consequence of adaptation to permanent low temperatures and high salinity. To understand whether CEF represents a broader acclimation strategy to short- and long-term stress, we compared high salt acclimation between the halotolerant UWO241, the salt-sensitive model, C. reinhardtii, and a moderately halotolerant Antarctic green alga, C. sp. ICE-MDV (ICE-MDV). CEF was activated under high salt and associated with increased non-photochemical quenching in all three Chlamydomonas species. Furthermore, high salt-acclimated cells of either strain formed a PSI-supercomplex, while state transition capacity was attenuated. How the CEF-associated PSI-supercomplex interferes with state transition response is not yet known. We present a model for interaction between PSI-supercomplex formation, state transitions, and the important role of CEF for survival during long-term exposure to high salt.
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Affiliation(s)
- Isha Kalra
- Department of Microbiology, Miami University, Oxford, OH 45056 USA
- Present Address: Department of Biology, University of Southern California, Los Angeles, CA 90089 USA
| | - Xin Wang
- Department of Microbiology, Miami University, Oxford, OH 45056 USA
| | - Ru Zhang
- Donald Danforth Plant Science Center, St. Louis, MO 63132 USA
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6
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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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7
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Kupriyanova EV, Pronina NA, Los DA. Adapting from Low to High: An Update to CO 2-Concentrating Mechanisms of Cyanobacteria and Microalgae. PLANTS (BASEL, SWITZERLAND) 2023; 12:1569. [PMID: 37050194 PMCID: PMC10096703 DOI: 10.3390/plants12071569] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 06/19/2023]
Abstract
The intracellular accumulation of inorganic carbon (Ci) by microalgae and cyanobacteria under ambient atmospheric CO2 levels was first documented in the 80s of the 20th Century. Hence, a third variety of the CO2-concentrating mechanism (CCM), acting in aquatic photoautotrophs with the C3 photosynthetic pathway, was revealed in addition to the then-known schemes of CCM, functioning in CAM and C4 higher plants. Despite the low affinity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) of microalgae and cyanobacteria for the CO2 substrate and low CO2/O2 specificity, CCM allows them to perform efficient CO2 fixation in the reductive pentose phosphate (RPP) cycle. CCM is based on the coordinated operation of strategically located carbonic anhydrases and CO2/HCO3- uptake systems. This cooperation enables the intracellular accumulation of HCO3-, which is then employed to generate a high concentration of CO2 molecules in the vicinity of Rubisco's active centers compensating up for the shortcomings of enzyme features. CCM functions as an add-on to the RPP cycle while also acting as an important regulatory link in the interaction of dark and light reactions of photosynthesis. This review summarizes recent advances in the study of CCM molecular and cellular organization in microalgae and cyanobacteria, as well as the fundamental principles of its functioning and regulation.
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8
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Cazzaniga S, Perozeni F, Baier T, Ballottari M. Engineering astaxanthin accumulation reduces photoinhibition and increases biomass productivity under high light in Chlamydomonas reinhardtii. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:77. [PMID: 35820961 PMCID: PMC9277849 DOI: 10.1186/s13068-022-02173-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/28/2022] [Indexed: 11/10/2022]
Abstract
Background Astaxanthin is a highly valuable ketocarotenoid with strong antioxidative activity and is natively accumulated upon environmental stress exposure in selected microorganisms. Green microalgae are photosynthetic, unicellular organisms cultivated in artificial systems to produce biomass and industrially relevant bioproducts. While light is required for photosynthesis, fueling carbon fixation processes, application of high irradiance causes photoinhibition and limits biomass productivity. Results Here, we demonstrate that engineered astaxanthin accumulation in the green alga Chlamydomonas reinhardtii conferred high light tolerance, reduced photoinhibition and improved biomass productivity at high irradiances, likely due to strong antioxidant properties of constitutively accumulating astaxanthin. In competitive co-cultivation experiments, astaxanthin-rich Chlamydomonas reinhardtii outcompeted its corresponding parental background strain and even the fast-growing green alga Chlorella vulgaris. Conclusions Metabolic engineering inducing astaxanthin and ketocarotenoids accumulation caused improved high light tolerance and increased biomass productivity in the model species for microalgae Chlamydomonas reinhardtii. Thus, engineering microalgal pigment composition represents a powerful strategy to improve biomass productivities in customized photobioreactors setups. Moreover, engineered astaxanthin accumulation in selected strains could be proposed as a novel strategy to outperform growth of other competing microalgal strains. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02173-3.
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9
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Broddrick JT, Ware MA, Jallet D, Palsson BO, Peers G. Integration of physiologically relevant photosynthetic energy flows into whole genome models of light-driven metabolism. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 112:603-621. [PMID: 36053127 PMCID: PMC9826171 DOI: 10.1111/tpj.15965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 08/25/2022] [Accepted: 08/31/2022] [Indexed: 06/01/2023]
Abstract
Characterizing photosynthetic productivity is necessary to understand the ecological contributions and biotechnology potential of plants, algae, and cyanobacteria. Light capture efficiency and photophysiology have long been characterized by measurements of chlorophyll fluorescence dynamics. However, these investigations typically do not consider the metabolic network downstream of light harvesting. By contrast, genome-scale metabolic models capture species-specific metabolic capabilities but have yet to incorporate the rapid regulation of the light harvesting apparatus. Here, we combine chlorophyll fluorescence parameters defining photosynthetic and non-photosynthetic yield of absorbed light energy with a metabolic model of the pennate diatom Phaeodactylum tricornutum. This integration increases the model predictive accuracy regarding growth rate, intracellular oxygen production and consumption, and metabolic pathway usage. Through the quantification of excess electron transport, we uncover the sequential activation of non-radiative energy dissipation processes, cross-compartment electron shuttling, and non-photochemical quenching as the rapid photoacclimation strategy in P. tricornutum. Interestingly, the photon absorption thresholds that trigger the transition between these mechanisms were consistent at low and high incident photon fluxes. We use this understanding to explore engineering strategies for rerouting cellular resources and excess light energy towards bioproducts in silico. Overall, we present a methodology for incorporating a common, informative data type into computational models of light-driven metabolism and show its utilization within the design-build-test-learn cycle for engineering of photosynthetic organisms.
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Affiliation(s)
- Jared T. Broddrick
- Division of Biological SciencesUniversity of California, San DiegoLa JollaCA92093USA
- Department of BioengineeringUniversity of California, San DiegoLa JollaCA92093USA
- Space Biosciences Research BranchNASA Ames Research CenterMoffett FieldCA94035USA
| | - Maxwell A. Ware
- Department of BiologyColorado State UniversityFort CollinsCO80524USA
| | - Denis Jallet
- Department of BiologyColorado State UniversityFort CollinsCO80524USA
| | - Bernhard O. Palsson
- Department of BioengineeringUniversity of California, San DiegoLa JollaCA92093USA
| | - Graham Peers
- Department of BiologyColorado State UniversityFort CollinsCO80524USA
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10
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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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11
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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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12
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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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13
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Stahl-Rommel S, Kalra I, D'Silva S, Hahn MM, Popson D, Cvetkovska M, Morgan-Kiss RM. Cyclic electron flow (CEF) and ascorbate pathway activity provide constitutive photoprotection for the photopsychrophile, Chlamydomonas sp. UWO 241 (renamed Chlamydomonas priscuii). PHOTOSYNTHESIS RESEARCH 2022; 151:235-250. [PMID: 34609708 DOI: 10.1007/s11120-021-00877-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
Under environmental stress, plants and algae employ a variety of strategies to protect the photosynthetic apparatus and maintain photostasis. To date, most studies on stress acclimation have focused on model organisms which possess limited to no tolerance to stressful extremes. We studied the ability of the Antarctic alga Chlamydomonas sp. UWO 241 (UWO 241) to acclimate to low temperature, high salinity or high light. UWO 241 maintained robust growth and photosynthetic activity at levels of temperature (2 °C) and salinity (700 mM NaCl) which were nonpermissive for a mesophilic sister species, Chlamydomonas raudensis SAG 49.72 (SAG 49.72). Acclimation in the mesophile involved classic mechanisms, including downregulation of light harvesting and shifts in excitation energy between photosystem I and II. In contrast, UWO 241 exhibited high rates of PSI-driven cyclic electron flow (CEF) and a larger capacity for nonphotochemical quenching (NPQ). Furthermore, UWO 241 exhibited constitutively high activity of two key ascorbate cycle enzymes, ascorbate peroxidase and glutathione reductase and maintained a large ascorbate pool. These results matched the ability of the psychrophile to maintain low ROS under short-term photoinhibition conditions. We conclude that tight control over photostasis and ROS levels are essential for photosynthetic life to flourish in a native habitat of permanent photooxidative stress. We propose to rename this organism Chlamydomonas priscuii.
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Affiliation(s)
- Sarah Stahl-Rommel
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
- JES Tech, Houston, TX, 77058, USA
| | - Isha Kalra
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
| | - Susanna D'Silva
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
| | - Mark M Hahn
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
| | - Devon Popson
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA
| | - Marina Cvetkovska
- Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Rachael M Morgan-Kiss
- Department of Microbiology, Miami University, Oxford, OH, 45045, USA.
- Department of Microbiology, Miami University, 700 E High St., 212 Pearson Hall, Oxford, OH, 45056, USA.
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14
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Neofotis P, Temple J, Tessmer OL, Bibik J, Norris N, Pollner E, Lucker B, Weraduwage SM, Withrow A, Sears B, Mogos G, Frame M, Hall D, Weissman J, Kramer DM. The induction of pyrenoid synthesis by hyperoxia and its implications for the natural diversity of photosynthetic responses in Chlamydomonas. eLife 2021; 10:67565. [PMID: 34936552 PMCID: PMC8694700 DOI: 10.7554/elife.67565] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 11/13/2021] [Indexed: 12/31/2022] Open
Abstract
In algae, it is well established that the pyrenoid, a component of the carbon-concentrating mechanism (CCM), is essential for efficient photosynthesis at low CO2. However, the signal that triggers the formation of the pyrenoid has remained elusive. Here, we show that, in Chlamydomonas reinhardtii, the pyrenoid is strongly induced by hyperoxia, even at high CO2 or bicarbonate levels. These results suggest that the pyrenoid can be induced by a common product of photosynthesis specific to low CO2 or hyperoxia. Consistent with this view, the photorespiratory by-product, H2O2, induced the pyrenoid, suggesting that it acts as a signal. Finally, we show evidence for linkages between genetic variations in hyperoxia tolerance, H2O2 signaling, and pyrenoid morphologies.
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Affiliation(s)
- Peter Neofotis
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Joshua Temple
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Plant Biology, Michigan State University, East Lansing, United States
| | - Oliver L Tessmer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Jacob Bibik
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Nicole Norris
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Eric Pollner
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Ben Lucker
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Sarathi M Weraduwage
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States.,Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, United States
| | - Alecia Withrow
- Center for Advanced Microscopy, Michigan State University, East Lansing, United States
| | - Barbara Sears
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Greg Mogos
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Melinda Frame
- Center for Advanced Microscopy, Michigan State University, East Lansing, United States
| | - David Hall
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Joseph Weissman
- Corporate Strategic Research, ExxonMobil, Annandale, United States
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
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15
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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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16
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Jiang Y, Feng X, Wang H, Chen Y, Sun Y. Heat-induced down-regulation of photosystem II protects photosystem I in honeysuckle (Lonicera japonica). JOURNAL OF PLANT RESEARCH 2021; 134:1311-1321. [PMID: 34351552 DOI: 10.1007/s10265-021-01336-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Honeysuckle (Lonicera japonica Thunb.) is a traditional medicinal plant in China which is often threatened by high temperature at midday during summer. Heat-induced effects on the photosynthetic apparatus in honeysuckle are associated with a depression of the photosystem II (PSII) photochemical efficiency. However, very limited information is available on regulation of photosynthetic electron flow in PSI photoprotection in heat-stressed honeysuckle. Simultaneous analyses of chlorophyll fluorescence and the change in absorbance of P700 showed that energy transformation and electron transfer activity in PSII decreased under heat stress, but the fraction of photo-oxidizable PSI (Pm) remained stable. With treatments at 38 and 42 °C, the photochemical electron transport in PSII was suppressed, whereas the cyclic electron flow (CEF) around PSI was induced. In addition, the levels of high energy state quenching (qE) and P700 oxidation increased significantly with increasing temperature. However, a decline of qE in antimycin A (AA)- or 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)-treated leaves after heat treatment was observed, while P700 oxidation decreased only in the presence of AA. The results indicate that heat-induced inhibition of PSII and induction of CEF cooperatively protect PSI from ROS damages through moderate down-regulation of photosynthetic electron flow from PSII to PSI.
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Affiliation(s)
- Ying Jiang
- Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Xin Feng
- Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Hui Wang
- College of Horticulture, Northwest Agriculture and Forestry University, Yangling, Xianyang, 712100, China
| | - Yuqing Chen
- Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Yongjiang Sun
- Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, 100083, China.
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17
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Cinq-Mars M, Samson G. Down-Regulation of Photosynthetic Electron Transport and Decline in CO2 Assimilation under Low Frequencies of Pulsed Lights. PLANTS 2021; 10:plants10102033. [PMID: 34685841 PMCID: PMC8540243 DOI: 10.3390/plants10102033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/17/2021] [Accepted: 09/23/2021] [Indexed: 11/16/2022]
Abstract
The decline in CO2 assimilation in leaves exposed to decreasing frequencies of pulsed light is well characterized, in contrast to the regulation of photosynthetic electron transport under these conditions. Thus, we exposed sunflower leaves to pulsed lights of different frequencies but with the same duty ratio (25%) and averaged light intensity (575 μmoles photons m−2 s−1). The rates of net photosynthesis Pn were constant from 125 to 10 Hz, and declined by 70% from 10 to 0.1 Hz. This decline coincided with (1) a marked increase in nonphotochemical quenching (NPQ), and (2) the completion after 25 ms of illumination of the first phase of P700 photooxidation, the primary electron donor of PSI. Under longer light pulses (<5 Hz), there was a slower and larger P700 photooxidation phase that could be attributed to the larger NPQ and to a resistance of electron flow on the PSI donor side indicated by 44% slower kinetics of a P700+ dark reduction. In addition, at low frequencies, the decrease in quantum yield of photochemistry was 2.3-times larger for PSII than for PSI. Globally, our results indicate that the decline in CO2 assimilation at 10 Hz and lower frequencies coincide with the formation of NPQ and a restriction of electron flows toward PSI, favoring the accumulation of harmless P700+.
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18
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Blifernez-Klassen O, Berger H, Mittmann BGK, Klassen V, Schelletter L, Buchholz T, Baier T, Soleimani M, Wobbe L, Kruse O. A gene regulatory network for antenna size control in carbon dioxide-deprived Chlamydomonas reinhardtii cells. THE PLANT CELL 2021; 33:1303-1318. [PMID: 33793853 DOI: 10.1093/plcell/koab012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
In green microalgae, prolonged exposure to inorganic carbon depletion requires long-term acclimation responses, involving modulated gene expression and the adjustment of photosynthetic activity to the prevailing supply of carbon dioxide. Here, we describe a microalgal regulatory cycle that adjusts the light-harvesting capacity at photosystem II (PSII) to the prevailing supply of carbon dioxide in Chlamydomonas (Chlamydomonas reinhardtii). It engages low carbon dioxide response factor (LCRF), a member of the squamosa promoter-binding protein (SBP) family of transcription factors, and the previously characterized cytosolic translation repressor nucleic acid-binding protein 1 (NAB1). LCRF combines a DNA-binding SBP domain with a conserved domain for protein-protein interaction. LCRF transcription is rapidly induced by carbon dioxide depletion. LCRF activates NAB1 transcription by specifically binding to tetranucleotide motifs present in its promoter. Accumulation of the NAB1 protein enhances translational repression of its prime target mRNA, encoding the PSII-associated major light-harvesting protein LHCBM6. The resulting truncation of the PSII antenna size helps maintaining a low excitation during carbon dioxide limitation. Analyses of low carbon dioxide acclimation in nuclear insertion mutants devoid of a functional LCRF gene confirm the essentiality of this novel transcription factor for the regulatory circuit.
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Affiliation(s)
- Olga Blifernez-Klassen
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Hanna Berger
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Birgit Gerlinde Katharina Mittmann
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Viktor Klassen
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Louise Schelletter
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Tatjana Buchholz
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Thomas Baier
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Maryna Soleimani
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Lutz Wobbe
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Olaf Kruse
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
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19
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Elucidation and genetic intervention of CO2 concentration mechanism in Chlamydomonas reinhardtii for increased plant primary productivity. J Biosci 2020. [DOI: 10.1007/s12038-020-00080-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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20
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Patil PP, Vass I, Kodru S, Szabó M. A multi-parametric screening platform for photosynthetic trait characterization of microalgae and cyanobacteria under inorganic carbon limitation. PLoS One 2020; 15:e0236188. [PMID: 32701995 PMCID: PMC7377499 DOI: 10.1371/journal.pone.0236188] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/30/2020] [Indexed: 11/18/2022] Open
Abstract
Microalgae and cyanobacteria are considered as important model organisms to investigate the biology of photosynthesis; moreover, they are valuable sources of biomolecules for several biotechnological applications. Understanding the species-specific traits of photosynthetic electron transport is extremely important, because it contributes to the regulation of ATP/NADPH ratio, which has direct/indirect links to carbon fixation and other metabolic pathways and thus overall growth and biomass production. In the present work, a cuvette-based setup is developed, in which a combination of measurements of dissolved oxygen, pH, chlorophyll fluorescence and NADPH kinetics can be performed without disturbing the physiological status of the sample. The suitability of the system is demonstrated using a model cyanobacterium Synechocystis sp. PCC6803, as well as biofuel-candidate microalgae species, such as Chlorella sorokiniana, Dunaliella salina and Nannochloropsis limnetica undergoing inorganic carbon (Ci) limitation. Inorganic carbon limitation, induced by photosynthetic Ci uptake under continuous illumination, caused a decrease in the effective quantum yield of PSII (Y(II)) and loss of oxygen-evolving capacity in all species investigated here; these effects were largely recovered by the addition of NaHCO3. Detailed analysis of the dark-light and light-dark transitions of NADPH production/uptake and changes in chlorophyll fluorescence kinetics revealed species- and condition-specific responses. These responses indicate that the impact of decreased Calvin-Benson cycle activity on photosynthetic electron transport pathways involving several sections of the electron transport chain (such as electron transfer via the QA-QB-plastoquinone pool, the redox state of the plastoquinone pool) can be analyzed with high sensitivity in a comparative manner. Therefore, the integrated system presented here can be applied for screening for specific traits in several significant species at different stages of inorganic carbon limitation, a condition that strongly impacts primary productivity.
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Affiliation(s)
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Sandeesha Kodru
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Biology PhD School, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Milán Szabó
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Climate Change Cluster, University of Technology Sydney, Ultimo, Australia
- * E-mail:
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21
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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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22
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Walker BJ, Kramer DM, Fisher N, Fu X. Flexibility in the Energy Balancing Network of Photosynthesis Enables Safe Operation under Changing Environmental Conditions. PLANTS (BASEL, SWITZERLAND) 2020; 9:E301. [PMID: 32121540 PMCID: PMC7154899 DOI: 10.3390/plants9030301] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/13/2020] [Accepted: 02/15/2020] [Indexed: 12/11/2022]
Abstract
Given their ability to harness chemical energy from the sun and generate the organic compounds necessary for life, photosynthetic organisms have the unique capacity to act simultaneously as their own power and manufacturing plant. This dual capacity presents many unique challenges, chiefly that energy supply must be perfectly balanced with energy demand to prevent photodamage and allow for optimal growth. From this perspective, we discuss the energy balancing network using recent studies and a quantitative framework for calculating metabolic ATP and NAD(P)H demand using measured leaf gas exchange and assumptions of metabolic demand. We focus on exploring how the energy balancing network itself is structured to allow safe and flexible energy supply. We discuss when the energy balancing network appears to operate optimally and when it favors high capacity instead. We also present the hypothesis that the energy balancing network itself can adapt over longer time scales to a given metabolic demand and how metabolism itself may participate in this energy balancing.
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Affiliation(s)
- Berkley J. Walker
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
- Department of Plant Biology, Michigan State University, East Lansing, MI 48823, USA
| | - David M. Kramer
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA
| | - Nicholas Fisher
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
| | - Xinyu Fu
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48823, USA; (D.M.K.); (N.F.); (X.F.)
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23
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Cazzaniga S, Kim M, Bellamoli F, Jeong J, Lee S, Perozeni F, Pompa A, Jin E, Ballottari M. Photosystem II antenna complexes CP26 and CP29 are essential for nonphotochemical quenching in Chlamydomonas reinhardtii. PLANT, CELL & ENVIRONMENT 2020; 43:496-509. [PMID: 31724187 PMCID: PMC7004014 DOI: 10.1111/pce.13680] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/04/2019] [Indexed: 05/08/2023]
Abstract
Photosystems must balance between light harvesting to fuel the photosynthetic process for CO2 fixation and mitigating the risk of photodamage due to absorption of light energy in excess. Eukaryotic photosynthetic organisms evolved an array of pigment-binding proteins called light harvesting complexes constituting the external antenna system in the photosystems, where both light harvesting and activation of photoprotective mechanisms occur. In this work, the balancing role of CP29 and CP26 photosystem II antenna subunits was investigated in Chlamydomonas reinhardtii using CRISPR-Cas9 technology to obtain single and double mutants depleted of monomeric antennas. Absence of CP26 and CP29 impaired both photosynthetic efficiency and photoprotection: Excitation energy transfer from external antenna to reaction centre was reduced, and state transitions were completely impaired. Moreover, differently from higher plants, photosystem II monomeric antenna proteins resulted to be essential for photoprotective thermal dissipation of excitation energy by nonphotochemical quenching.
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Affiliation(s)
| | - Minjae Kim
- Department of Life ScienceHanyang UniversitySeoulSouth Korea
| | | | - Jooyoen Jeong
- Department of Life ScienceHanyang UniversitySeoulSouth Korea
| | - Sangmuk Lee
- Department of Life ScienceHanyang UniversitySeoulSouth Korea
| | | | - Andrea Pompa
- Dipartimento di Scienze BiomolecolariUniversità degli Studi di UrbinoUrbinoItaly
- Istituto di Bioscienze e BiorisorseConsiglio Nazionale delle RicerchePerugiaItaly
| | - EonSeon Jin
- Department of Life ScienceHanyang UniversitySeoulSouth Korea
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24
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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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25
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Regulation of photosynthetic cyclic electron flow pathways by adenylate status in higher plant chloroplasts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:148081. [PMID: 31520615 DOI: 10.1016/j.bbabio.2019.148081] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/01/2019] [Accepted: 09/08/2019] [Indexed: 01/08/2023]
Abstract
Cylic electron flow (CEF) around Photosystem I in photosynthetic eukaryotes is likely to be necessary to augment ATP production, rapidly- and precisely balancing the plastid ATP/NADPH energy budget to meet the demands of downstream metabolism. Many regulatory aspects of this process are unclear. Here we demonstrate that the higher plant plastid NADH/Fd:plastoquinone reductase (NDH) and proposed PGR5/PGRL1 ferredoxin:plastoquinone reductase (FQR) pathways of CEF are strongly, rapidly and reversibly inhibited in vitro by ATP with Ki values of 670 μM and 240 μM respectively, within the range of physiological changes in ATP concentrations. Control experiments ruled out effects on secondary reactions, e.g. FNR- and cytochrome b6f activity, nonphotochemical quenching of chlorophyll fluorescence etc., supporting the view that ATP is an inhibitor of CEF and its associated pmf generation and subsequent ATP production. The effects are specific to ATP, with the ATP analog AMP-PNP showing little inhibitory effect, and ADP inhibiting only at higher concentrations. For the FQR pathway, inhibition was found to be classically competitive with Fd, and the NDH pathway showing partial competition with Fd. We propose a straightforward model for regulation of CEF in plants in which CEF is activated under conditions when stromal ATP low, but is downregulated as ATP levels build up, allowing for effective ATP homeostasis. The differences in Ki values suggest a two-tiered regulatory system, where the highly efficient proton pumping NDH is activated with moderate decreases in ATP, with the less energetically-efficient FQR pathway being activated under more severe ATP depletion.
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26
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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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Cook G, Teufel A, Kalra I, Li W, Wang X, Priscu J, Morgan-Kiss R. The Antarctic psychrophiles Chlamydomonas spp. UWO241 and ICE-MDV exhibit differential restructuring of photosystem I in response to iron. PHOTOSYNTHESIS RESEARCH 2019; 141:209-228. [PMID: 30729447 DOI: 10.1007/s11120-019-00621-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 01/25/2019] [Indexed: 06/09/2023]
Abstract
Chlamydomonas sp. UWO241 is a psychrophilic alga isolated from the deep photic zone of a perennially ice-covered Antarctic lake (east lobe Lake Bonney, ELB). Past studies have shown that C. sp. UWO241 exhibits constitutive downregulation of photosystem I (PSI) and high rates of PSI-associated cyclic electron flow (CEF). Iron levels in ELB are in the nanomolar range leading us to hypothesize that the unusual PSI phenotype of C. sp. UWO241 could be a response to chronic Fe-deficiency. We studied the impact of Fe availability in C. sp. UWO241, a mesophile, C. reinhardtii SAG11-32c, as well as a psychrophile isolated from the shallow photic zone of ELB, Chlamydomonas sp. ICE-MDV. Under Fe-deficiency, PsaA abundance and levels of photooxidizable P700 (ΔA820/A820) were reduced in both psychrophiles relative to the mesophile. Upon increasing Fe, C. sp. ICE-MDV and C. reinhardtii exhibited restoration of PSI function, while C. sp. UWO241 exhibited only moderate changes in PSI activity and lacked almost all LHCI proteins. Relative to Fe-excess conditions (200 µM Fe2+), C. sp. UWO241 grown in 18 µM Fe2+ exhibited downregulation of light harvesting and photosystem core proteins, as well as upregulation of a bestrophin-like anion channel protein and two CEF-associated proteins (NdsS, PGL1). Key enzymes of starch synthesis and shikimate biosynthesis were also upregulated. We conclude that in response to variable Fe availability, the psychrophile C. sp. UWO241 exhibits physiological plasticity which includes restructuring of the photochemical apparatus, increased PSI-associated CEF, and shifts in downstream carbon metabolism toward storage carbon and secondary stress metabolites.
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Affiliation(s)
- Greg Cook
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA
| | - Amber Teufel
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA
| | - Isha Kalra
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA
| | - Wei Li
- Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - Xin Wang
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA
| | - John Priscu
- Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - Rachael Morgan-Kiss
- Department of Microbiology, Miami University, 700 E High St., 32 Pearson Hall, Oxford, OH, 45056, USA.
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Gasulla F, Casano L, Guéra A. Chlororespiration induces non-photochemical quenching of chlorophyll fluorescence during darkness in lichen chlorobionts. PHYSIOLOGIA PLANTARUM 2019; 166:538-552. [PMID: 29952012 DOI: 10.1111/ppl.12792] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 06/15/2018] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Affiliation(s)
- Francisco Gasulla
- Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus Científico-Tecnológico (Externo), 28802, Alcalá de Henares (Madrid), Spain
| | - Leonardo Casano
- Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus Científico-Tecnológico (Externo), 28802, Alcalá de Henares (Madrid), Spain
| | - Alfredo Guéra
- Departamento de Ciencias de la Vida, Universidad de Alcalá, Edificio de Ciencias, Campus Científico-Tecnológico (Externo), 28802, Alcalá de Henares (Madrid), Spain
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29
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Sunil B, Saini D, Bapatla RB, Aswani V, Raghavendra AS. Photorespiration is complemented by cyclic electron flow and the alternative oxidase pathway to optimize photosynthesis and protect against abiotic stress. PHOTOSYNTHESIS RESEARCH 2019; 139:67-79. [PMID: 30187303 DOI: 10.1007/s11120-018-0577-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/24/2018] [Indexed: 05/02/2023]
Abstract
Optimization of photosynthetic performance and protection against abiotic stress are essential to sustain plant growth. Photorespiratory metabolism can help plants to adapt to abiotic stress. The beneficial role of photorespiration under abiotic stress is further strengthened by cyclic electron flow (CEF) and alternative oxidase (AOX) pathways. We have attempted to critically assess the literature on the responses of these three phenomena-photorespiration, CEF and AOX, to different stress situations. We emphasize that photorespiration is the key player to protect photosynthesis and upregulates CEF as well as AOX. Then these three processes work in coordination to protect the plants against photoinhibition and maintain an optimal redox state in the cell, while providing ATP for metabolism and protein repair. H2O2 generated during photorespiratory metabolism seems to be an important signal to upregulate CEF or AOX. Further experiments are necessary to identify the signals originating from CEF or AOX to modulate photorespiration. The mutants deficient in CEF or AOX or both could be useful in this regard. The mutual interactions between CEF and AOX, so as to keep their complementarity, are also to be examined further.
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Affiliation(s)
- Bobba Sunil
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Deepak Saini
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Ramesh B Bapatla
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Vetcha Aswani
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Agepati S Raghavendra
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India.
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Structure of a PSI-LHCI-cyt b 6f supercomplex in Chlamydomonas reinhardtii promoting cyclic electron flow under anaerobic conditions. Proc Natl Acad Sci U S A 2018; 115:10517-10522. [PMID: 30254175 DOI: 10.1073/pnas.1809973115] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Photosynthetic linear electron flow (LEF) produces ATP and NADPH, while cyclic electron flow (CEF) exclusively drives photophosphorylation to supply extra ATP. The fine-tuning of linear and cyclic electron transport levels allows photosynthetic organisms to balance light energy absorption with cellular energy requirements under constantly changing light conditions. As LEF and CEF share many electron transfer components, a key question is how the same individual structural units contribute to these two different functional modes. Here, we report the structural identification of a photosystem I (PSI)-light harvesting complex I (LHCI)-cytochrome (cyt) b6f supercomplex isolated from the unicellular alga Chlamydomonas reinhardtii under anaerobic conditions, which induces CEF. This provides strong evidence for the model that enhanced CEF is induced by the formation of CEF supercomplexes, when stromal electron carriers are reduced, to generate additional ATP. The additional identification of PSI-LHCI-LHCII complexes is consistent with recent findings that both CEF enhancement and state transitions are triggered by similar conditions, but can occur independently from each other. Single molecule fluorescence correlation spectroscopy indicates a physical association between cyt b6f and fluorescent chlorophyll containing PSI-LHCI supercomplexes. Single particle analysis identified top-view projections of the corresponding PSI-LHCI-cyt b6f supercomplex. Based on molecular modeling and mass spectrometry analyses, we propose a model in which dissociation of LHCA2 and LHCA9 from PSI supports the formation of this CEF supercomplex. This is supported by the finding that a Δlhca2 knockout mutant has constitutively enhanced CEF.
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Effect of carbon limitation on photosynthetic electron transport in Nannochloropsis oculata. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 181:31-43. [PMID: 29486460 DOI: 10.1016/j.jphotobiol.2018.02.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 02/17/2018] [Accepted: 02/17/2018] [Indexed: 01/31/2023]
Abstract
This study describes the impacts of inorganic carbon limitation on the photosynthetic efficiency and operation of photosynthetic electron transport pathways in the biofuel-candidate microalga Nannochloropsis oculata. Using a combination of highly-controlled cultivation setup (photobioreactor), variable chlorophyll a fluorescence and transient spectroscopy methods (electrochromic shift (ECS) and P700 redox kinetics), we showed that net photosynthesis and effective quantum yield of Photosystem II (PSII) decreased in N. oculata under carbon limitation. This was accompanied by a transient increase in total proton motive force and energy-dependent non-photochemical quenching as well as slightly elevated respiration. On the other hand, under carbon limitation the rapid increase in proton motive force (PMF, estimated from the total ECS signal) was also accompanied by reduced conductivity of ATP synthase to protons (estimated from the rate of ECS decay in dark after actinic illumination). This indicates that the slow operation of ATP synthase results in the transient build-up of PMF, which leads to the activation of fast energy dissipation mechanisms such as energy-dependent non-photochemical quenching. N. oculata also increased content of lipids under carbon limitation, which compensated for reduced NAPDH consumption during decreased CO2 fixation. The integrated knowledge of the underlying energetic regulation of photosynthetic processes attained with a combination of biophysical methods may be used to identify photo-physiological signatures of the onset of carbon limitation in microalgal cultivation systems, as well as to potentially identify microalgal strains that can better acclimate to carbon limitation.
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Lucker B, Schwarz E, Kuhlgert S, Ostendorf E, Kramer DM. Spectroanalysis in native gels (SING): rapid spectral analysis of pigmented thylakoid membrane complexes separated by CN-PAGE. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:744-756. [PMID: 28865165 DOI: 10.1111/tpj.13703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/22/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Photosynthetic organisms rapidly adjust the capture, transfer and utilization of light energy to optimize the efficiency of photosynthesis and avoid photodamage. These adjustments involve fine-tuning of expression levels and mutual interactions among electron/proton transfer components and their associated light-harvesting antenna. Detailed studies of these interactions and their dynamics have been hindered by the low throughput and resolution of currently available research tools, which involve laborious isolation, separation and characterization steps. To address these issues, we developed an approach that measured multiple spectroscopic properties of thylakoid preparations directly in native polyacrylamide gel electrophoresis gels, enabling unprecedented resolution of photosynthetic complexes, both in terms of the spectroscopic and functional details, as well as the ability to distinguish separate complexes and thus test their functional connections. As a demonstration, we explore the thylakoid membrane components of Chlamydomonas reinhardtii acclimated to high and low light, using a combination of room temperature absorption and 77K fluorescence emission to generate a multi-dimensional molecular and spectroscopic map of the photosynthetic apparatus. We show that low-light-acclimated cells accumulate a photosystem I-containing megacomplex that is absent in high-light-acclimated cells and contains distinct LhcII proteins that can be distinguished based on their spectral signatures.
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Affiliation(s)
- Ben Lucker
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - Eliezer Schwarz
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - Sebastian Kuhlgert
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - Elisabeth Ostendorf
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
| | - David M Kramer
- Department of Biochemistry and Molecular Biology, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
- DOE-Plant Research Laboratory, S222 Plant Biology Building, Michigan State University, East Lansing, MI, 48824-1312, USA
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Ivanov AG, Velitchkova MY, Allakhverdiev SI, Huner NPA. Heat stress-induced effects of photosystem I: an overview of structural and functional responses. PHOTOSYNTHESIS RESEARCH 2017; 133:17-30. [PMID: 28391379 DOI: 10.1007/s11120-017-0383-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/03/2017] [Indexed: 05/24/2023]
Abstract
Temperature is one of the main factors controlling the formation, development, and functional performance of the photosynthetic apparatus in all photoautotrophs (green plants, algae, and cyanobacteria) on Earth. The projected climate change scenarios predict increases in air temperature across Earth's biomes ranging from moderate (3-4 °C) to extreme (6-8 °C) by the year 2100 (IPCC in Climate change 2007: The physical science basis: summery for policymakers, IPCC WG1 Fourth Assessment Report 2007; Climate change 2014: Mitigation of Climate Change, IPCC WG3 Fifth Assessment Report 2014). In some areas, especially of the Northern hemisphere, even more extreme warm seasonal temperatures may occur, which possibly will cause significant negative effects on the development, growth, and yield of important agricultural crops. It is well documented that high temperatures can cause direct damages of the photosynthetic apparatus and photosystem II (PSII) is generally considered to be the primary target of heat-induced inactivation of photosynthesis. However, since photosystem I (PSI) is considered to determine the global amount of enthalpy in living systems (Nelson in Biochim Biophys Acta 1807:856-863, 2011; Photosynth Res 116:145-151, 2013), the effects of elevated temperatures on PSI might be of vital importance for regulating the photosynthetic response of all photoautotrophs in the changing environment. In this review, we summarize the experimental data that demonstrate the critical impact of heat-induced alterations on the structure, composition, and functional performance of PSI and their significant implications on photosynthesis under future climate change scenarios.
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Affiliation(s)
- Alexander G Ivanov
- Department of Biology, University of Western Ontario, 1151 Richmond Street N., London, ON, N6A 5B7, Canada.
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Bl. 21, 1113, Sofia, Bulgaria.
| | - Maya Y Velitchkova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Bl. 21, 1113, Sofia, Bulgaria
| | - Suleyman I Allakhverdiev
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow, 127276, Russia
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow, 142290, Russia
- Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119991, Russia
- Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, Matbuat Avenue 2a, 1073, Baku, Azerbaijan
| | - Norman P A Huner
- Department of Biology, University of Western Ontario, 1151 Richmond Street N., London, ON, N6A 5B7, Canada
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Cantrell M, Peers G. A mutant of Chlamydomonas without LHCSR maintains high rates of photosynthesis, but has reduced cell division rates in sinusoidal light conditions. PLoS One 2017. [PMID: 28644828 PMCID: PMC5482440 DOI: 10.1371/journal.pone.0179395] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The LHCSR protein belongs to the light harvesting complex family of pigment-binding proteins found in oxygenic photoautotrophs. Previous studies have shown that this complex is required for the rapid induction and relaxation of excess light energy dissipation in a wide range of eukaryotic algae and moss. The ability of cells to rapidly regulate light harvesting between this dissipation state and one favoring photochemistry is believed to be important for reducing oxidative stress and maintaining high photosynthetic efficiency in a rapidly changing light environment. We found that a mutant of Chlamydomonas reinhardtii lacking LHCSR, npq4lhcsr1, displays minimal photoinhibition of photosystem II and minimal inhibition of short term oxygen evolution when grown in constant excess light compared to a wild type strain. We also investigated the impact of no LHCSR during growth in a sinusoidal light regime, which mimics daily changes in photosynthetically active radiation. The absence of LHCSR correlated with a slight reduction in the quantum efficiency of photosystem II and a stimulation of the maximal rates of photosynthesis compared to wild type. However, there was no reduction in carbon accumulation during the day. Another novel finding was that npq4lhcsr1 cultures underwent fewer divisions at night, reducing the overall growth rate compared to the wild type. Our results show that the rapid regulation of light harvesting mediated by LHCSR is required for high growth rates, but it is not required for efficient carbon accumulation during the day in a sinusoidal light environment. This finding has direct implications for engineering strategies directed at increasing photosynthetic productivity in mass cultures.
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Affiliation(s)
- Michael Cantrell
- Department of Biology, Colorado State University, Fort Collins, CO, United States of America
| | - Graham Peers
- Department of Biology, Colorado State University, Fort Collins, CO, United States of America
- * E-mail:
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Caspari OD, Meyer MT, Tolleter D, Wittkopp TM, Cunniffe NJ, Lawson T, Grossman AR, Griffiths H. Pyrenoid loss in Chlamydomonas reinhardtii causes limitations in CO2 supply, but not thylakoid operating efficiency. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3903-3913. [PMID: 28911055 PMCID: PMC5853600 DOI: 10.1093/jxb/erx197] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The pyrenoid of the unicellular green alga Chlamydomonas reinhardtii is a microcompartment situated in the centre of the cup-shaped chloroplast, containing up to 90% of cellular Rubisco. Traversed by a network of dense, knotted thylakoid tubules, the pyrenoid has been proposed to influence thylakoid biogenesis and ultrastructure. Mutants that are unable to assemble a pyrenoid matrix, due to expressing a vascular plant version of the Rubisco small subunit, exhibit severe growth and photosynthetic defects and have an ineffective carbon-concentrating mechanism (CCM). The present study set out to determine the cause of photosynthetic limitation in these pyrenoid-less lines. We tested whether electron transport and light use were compromised as a direct structural consequence of pyrenoid loss or as a metabolic effect downstream of lower CCM activity and resulting CO2 limitation. Thylakoid organization was unchanged in the mutants, including the retention of intrapyrenoid-type thylakoid tubules, and photosynthetic limitations associated with the absence of the pyrenoid were rescued by exposing cells to elevated CO2 levels. These results demonstrate that Rubisco aggregation in the pyrenoid functions as an essential element for CO2 delivery as part of the CCM, and does not play other roles in maintenance of photosynthetic membrane energetics.
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Affiliation(s)
- Oliver D Caspari
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, UK
- Correspondence:
| | - Moritz T Meyer
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, UK
| | - Dimitri Tolleter
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Tyler M Wittkopp
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Nik J Cunniffe
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, UK
| | - Tracy Lawson
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, UK
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Howard Griffiths
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, UK
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Alric J, Johnson X. Alternative electron transport pathways in photosynthesis: a confluence of regulation. CURRENT OPINION IN PLANT BIOLOGY 2017; 37:78-86. [PMID: 28426976 DOI: 10.1016/j.pbi.2017.03.014] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/23/2017] [Accepted: 03/28/2017] [Indexed: 05/19/2023]
Abstract
Photosynthetic reactions proceed along a linear electron transfer chain linking water oxidation at photosystem II (PSII) to CO2 reduction in the Calvin-Benson-Bassham cycle. Alternative pathways poise the electron carriers along the chain in response to changing light, temperature and CO2 inputs, under prolonged hydration stress and during development. We describe recent literature that reports the physiological functions of new molecular players. Such highlights include the flavodiiron proteins and their important role in the green lineage. The parsing of the proton-motive force between ΔpH and Δψ, regulated in many different ways (cyclic electron flow, ATPsynthase conductivity, ion/H+ transporters), is comprehensively reported. This review focuses on an integrated description of alternative electron transfer pathways and how they contribute to photosynthetic productivity in the context of plant fitness to the environment.
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Affiliation(s)
- Jean Alric
- CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix-Marseille, UMR 7265, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, Saint-Paul-lez-Durance F-13108, France
| | - Xenie Johnson
- CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix-Marseille, UMR 7265, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, Saint-Paul-lez-Durance F-13108, France.
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Wang L, Yamano T, Takane S, Niikawa Y, Toyokawa C, Ozawa SI, Tokutsu R, Takahashi Y, Minagawa J, Kanesaki Y, Yoshikawa H, Fukuzawa H. Chloroplast-mediated regulation of CO2-concentrating mechanism by Ca2+-binding protein CAS in the green alga Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A 2016; 113:12586-12591. [PMID: 27791081 PMCID: PMC5098658 DOI: 10.1073/pnas.1606519113] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Aquatic photosynthetic organisms, including the green alga Chlamydomonas reinhardtii, induce a CO2-concentrating mechanism (CCM) to maintain photosynthetic activity in CO2-limiting conditions by sensing environmental CO2 and light availability. Previously, a novel high-CO2-requiring mutant, H82, defective in the induction of the CCM, was isolated. A homolog of calcium (Ca2+)-binding protein CAS, originally found in Arabidopsis thaliana, was disrupted in H82 cells. Although Arabidopsis CAS is reported to be associated with stomatal closure or immune responses via a chloroplast-mediated retrograde signal, the relationship between a Ca2+ signal and the CCM associated with the function of CAS in an aquatic environment is still unclear. In this study, the introduction of an intact CAS gene into H82 cells restored photosynthetic affinity for inorganic carbon, and RNA-seq analyses revealed that CAS could function in maintaining the expression levels of nuclear-encoded CO2-limiting-inducible genes, including the HCO3- transporters high-light activated 3 (HLA3) and low-CO2-inducible gene A (LCIA). CAS changed its localization from dispersed across the thylakoid membrane in high-CO2 conditions or in the dark to being associated with tubule-like structures in the pyrenoid in CO2-limiting conditions, along with a significant increase of the fluorescent signals of the Ca2+ indicator in the pyrenoid. Chlamydomonas CAS had Ca2+-binding activity, and the perturbation of intracellular Ca2+ homeostasis by a Ca2+-chelator or calmodulin antagonist impaired the accumulation of HLA3 and LCIA. These results suggest that Chlamydomonas CAS is a Ca2+-mediated regulator of CCM-related genes via a retrograde signal from the pyrenoid in the chloroplast to the nucleus.
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Affiliation(s)
- Lianyong Wang
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Shunsuke Takane
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Yuki Niikawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Chihana Toyokawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Shin-Ichiro Ozawa
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Ryutaro Tokutsu
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Yuichiro Takahashi
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Yu Kanesaki
- NODAI Genome Research Center, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | - Hirofumi Yoshikawa
- Department of Bioscience, Tokyo University of Agriculture, Tokyo 156-8502, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan;
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Curien G, Flori S, Villanova V, Magneschi L, Giustini C, Forti G, Matringe M, Petroutsos D, Kuntz M, Finazzi G. The Water to Water Cycles in Microalgae. PLANT & CELL PHYSIOLOGY 2016; 57:1354-1363. [PMID: 26955846 DOI: 10.1093/pcp/pcw048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 02/23/2016] [Indexed: 05/28/2023]
Abstract
In oxygenic photosynthesis, light produces ATP plus NADPH via linear electron transfer, i.e. the in-series activity of the two photosystems: PSI and PSII. This process, however, is thought not to be sufficient to provide enough ATP per NADPH for carbon assimilation in the Calvin-Benson-Bassham cycle. Thus, it is assumed that additional ATP can be generated by alternative electron pathways. These circuits produce an electrochemical proton gradient without NADPH synthesis, and, although they often represent a small proportion of the linear electron flow, they could have a huge importance in optimizing CO2 assimilation. In Viridiplantae, there is a consensus that alternative electron flow comprises cyclic electron flow around PSI and the water to water cycles. The latter processes include photosynthetic O2 reduction via the Mehler reaction at PSI, the plastoquinone terminal oxidase downstream of PSII, photorespiration (the oxygenase activity of Rubisco) and the export of reducing equivalents towards the mitochondrial oxidases, through the malate shuttle. In this review, we summarize current knowledge about the role of the water to water cycles in photosynthesis, with a special focus on their occurrence and physiological roles in microalgae.
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Affiliation(s)
- Gilles Curien
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Serena Flori
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | | | - Leonardo Magneschi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Cécile Giustini
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Giorgio Forti
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Michel Matringe
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Dimitris Petroutsos
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Marcel Kuntz
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
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Strand DD, Livingston AK, Satoh-Cruz M, Koepke T, Enlow HM, Fisher N, Froehlich JE, Cruz JA, Minhas D, Hixson KK, Kohzuma K, Lipton M, Dhingra A, Kramer DM. Defects in the Expression of Chloroplast Proteins Leads to H 2O 2 Accumulation and Activation of Cyclic Electron Flow around Photosystem I. FRONTIERS IN PLANT SCIENCE 2016; 7:2073. [PMID: 28133462 PMCID: PMC5233679 DOI: 10.3389/fpls.2016.02073] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/28/2016] [Indexed: 05/02/2023]
Abstract
We describe a new member of the class of mutants in Arabidopsis exhibiting high rates of cyclic electron flow around photosystem I (CEF), a light-driven process that produces ATP but not NADPH. High cyclic electron flow 2 (hcef2) shows strongly increased CEF activity through the NADPH dehydrogenase complex (NDH), accompanied by increases in thylakoid proton motive force (pmf), activation of the photoprotective qE response, and the accumulation of H2O2. Surprisingly, hcef2 was mapped to a non-sense mutation in the TADA1 (tRNA adenosine deaminase arginine) locus, coding for a plastid targeted tRNA editing enzyme required for efficient codon recognition. Comparison of protein content from representative thylakoid complexes, the cytochrome bf complex, and the ATP synthase, suggests that inefficient translation of hcef2 leads to compromised complex assembly or stability leading to alterations in stoichiometries of major thylakoid complexes as well as their constituent subunits. Altered subunit stoichiometries for photosystem I, ratios and properties of cytochrome bf hemes, and the decay kinetics of the flash-induced thylakoid electric field suggest that these defect lead to accumulation of H2O2 in hcef2, which we have previously shown leads to activation of NDH-related CEF. We observed similar increases in CEF, as well as increases in H2O2 accumulation, in other translation defective mutants. This suggests that loss of coordination in plastid protein levels lead to imbalances in photosynthetic energy balance that leads to an increase in CEF. These results taken together with a large body of previous observations, support a general model in which processes that lead to imbalances in chloroplast energetics result in the production of H2O2, which in turn activates CEF. This activation could be from either H2O2 acting as a redox signal, or by a secondary effect from H2O2 inducing a deficit in ATP.
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Affiliation(s)
- Deserah D. Strand
- Department of Plant Biology, Michigan State UniversityEast Lansing, MI, USA
- DOE-Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
| | - Aaron K. Livingston
- Institute of Biological Chemistry, Washington State UniversityPullman, WA, USA
| | - Mio Satoh-Cruz
- DOE-Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
| | - Tyson Koepke
- Department of Horticulture, Washington State UniversityPullman, WA, USA
| | - Heather M. Enlow
- Institute of Biological Chemistry, Washington State UniversityPullman, WA, USA
| | - Nicholas Fisher
- DOE-Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
| | - John E. Froehlich
- DOE-Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State UniversityEast Lansing, MI, USA
| | - Jeffrey A. Cruz
- DOE-Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
| | - Deepika Minhas
- Department of Horticulture, Washington State UniversityPullman, WA, USA
| | - Kim K. Hixson
- Institute of Biological Chemistry, Washington State UniversityPullman, WA, USA
- Environmental Molecular Sciences Laboratory, Pacific Northwest National LaboratoryRichland, WA, USA
| | - Kaori Kohzuma
- DOE-Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
| | - Mary Lipton
- Environmental Molecular Sciences Laboratory, Pacific Northwest National LaboratoryRichland, WA, USA
| | - Amit Dhingra
- Department of Horticulture, Washington State UniversityPullman, WA, USA
| | - David M. Kramer
- Department of Plant Biology, Michigan State UniversityEast Lansing, MI, USA
- DOE-Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State UniversityEast Lansing, MI, USA
- *Correspondence: David M. Kramer
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Strand DD, Fisher N, Davis GA, Kramer DM. Redox regulation of the antimycin A sensitive pathway of cyclic electron flow around photosystem I in higher plant thylakoids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1-6. [DOI: 10.1016/j.bbabio.2015.07.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/27/2015] [Accepted: 07/29/2015] [Indexed: 10/23/2022]
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Alric J. The plastoquinone pool, poised for cyclic electron flow? FRONTIERS IN PLANT SCIENCE 2015; 6:540. [PMID: 26284081 PMCID: PMC4516869 DOI: 10.3389/fpls.2015.00540] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/03/2015] [Indexed: 05/05/2023]
Affiliation(s)
- Jean Alric
- Unité Mixte de Recherche 7265 Biologie Végétale et Microbiologie Environnementales, Laboratoire de Bioénergétique et de Biotechnologie des Bactéries et des Microalgues, Centre National de la Recherche Scientifique, Commissariat à l' Energie Atomique, Institut de Biologie Environmentale et BiotechnologieSaint-Paul-lez-Durance, France
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Energetic coupling between plastids and mitochondria drives CO2 assimilation in diatoms. Nature 2015; 524:366-9. [PMID: 26168400 DOI: 10.1038/nature14599] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/28/2015] [Indexed: 01/04/2023]
Abstract
Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by absorbing carbon dioxide from the atmosphere, sequestering it via the biological carbon pump and ultimately burying organic carbon in the lithosphere. The proportion of planetary primary production by diatoms in the modern oceans is roughly equivalent to that of terrestrial rainforests. In photosynthesis, the efficient conversion of carbon dioxide into organic matter requires a tight control of the ATP/NADPH ratio which, in other photosynthetic organisms, relies principally on a range of plastid-localized ATP generating processes. Here we show that diatoms regulate ATP/NADPH through extensive energetic exchanges between plastids and mitochondria. This interaction comprises the re-routing of reducing power generated in the plastid towards mitochondria and the import of mitochondrial ATP into the plastid, and is mandatory for optimized carbon fixation and growth. We propose that the process may have contributed to the ecological success of diatoms in the ocean.
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Bergner SV, Scholz M, Trompelt K, Barth J, Gäbelein P, Steinbeck J, Xue H, Clowez S, Fucile G, Goldschmidt-Clermont M, Fufezan C, Hippler M. STATE TRANSITION7-Dependent Phosphorylation Is Modulated by Changing Environmental Conditions, and Its Absence Triggers Remodeling of Photosynthetic Protein Complexes. PLANT PHYSIOLOGY 2015; 168:615-34. [PMID: 25858915 PMCID: PMC4453777 DOI: 10.1104/pp.15.00072] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/04/2015] [Indexed: 05/18/2023]
Abstract
In plants and algae, the serine/threonine kinase STN7/STT7, orthologous protein kinases in Chlamydomonas reinhardtii and Arabidopsis (Arabidopsis thaliana), respectively, is an important regulator in acclimation to changing light environments. In this work, we assessed STT7-dependent protein phosphorylation under high light in C. reinhardtii, known to fully induce the expression of light-harvesting complex stress-related protein3 (LHCSR3) and a nonphotochemical quenching mechanism, in relationship to anoxia where the activity of cyclic electron flow is stimulated. Our quantitative proteomics data revealed numerous unique STT7 protein substrates and STT7-dependent protein phosphorylation variations that were reliant on the environmental condition. These results indicate that STT7-dependent phosphorylation is modulated by the environment and point to an intricate chloroplast phosphorylation network responding in a highly sensitive and dynamic manner to environmental cues and alterations in kinase function. Functionally, the absence of the STT7 kinase triggered changes in protein expression and photoinhibition of photosystem I (PSI) and resulted in the remodeling of photosynthetic complexes. This remodeling initiated a pronounced association of LHCSR3 with PSI-light harvesting complex I (LHCI)-ferredoxin-NADPH oxidoreductase supercomplexes. Lack of STT7 kinase strongly diminished PSII-LHCII supercomplexes, while PSII core complex phosphorylation and accumulation were significantly enhanced. In conclusion, our study provides strong evidence that the regulation of protein phosphorylation is critical for driving successful acclimation to high light and anoxic growth environments and gives new insights into acclimation strategies to these environmental conditions.
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Affiliation(s)
- Sonja Verena Bergner
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Martin Scholz
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Kerstin Trompelt
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Johannes Barth
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Philipp Gäbelein
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Janina Steinbeck
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Huidan Xue
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Sophie Clowez
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Geoffrey Fucile
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Michel Goldschmidt-Clermont
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Christian Fufezan
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
| | - Michael Hippler
- Institute of Plant Biology and Biotechnology, University of Münster, 48143 Munster, Germany (S.V.B., M.S., K.T., J.B., P.G., J.S., H.X., C.F., M.H.);Institut de Biologie Physico-Chimique, Unité Mixte de Recherche 7141 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75005 Paris, France (S.C.); andDepartment of Botany and Plant Biology and Institute of Genetics and Genomics in Geneva, University of Geneva, CH-1211 Geneva 4, Switzerland (G.F., M.G.-C.)
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Wang Y, Stessman DJ, Spalding MH. The CO2 concentrating mechanism and photosynthetic carbon assimilation in limiting CO2 : how Chlamydomonas works against the gradient. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:429-448. [PMID: 25765072 DOI: 10.1111/tpj.12829] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/08/2015] [Accepted: 03/11/2015] [Indexed: 05/04/2023]
Abstract
The CO2 concentrating mechanism (CCM) represents an effective strategy for carbon acquisition that enables microalgae to survive and proliferate when the CO2 concentration limits photosynthesis. The CCM improves photosynthetic performance by raising the CO2 concentration at the site of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), simultaneously enhancing carbon fixation and suppressing photorespiration. Active inorganic carbon (Ci) uptake, Rubisco sequestration and interconversion between different Ci species catalyzed by carbonic anhydrases (CAs) are key components in the CCM, and an array of molecular regulatory elements is present to facilitate the sensing of CO2 availability, to regulate the expression of the CCM and to coordinate interplay between photosynthetic carbon metabolism and other metabolic processes in response to limiting CO2 conditions. This review intends to integrate our current understanding of the eukaryotic algal CCM and its interaction with carbon assimilation, based largely on Chlamydomonas as a model, and to illustrate how Chlamydomonas acclimates to limiting CO2 conditions and how its CCM is regulated.
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Affiliation(s)
- Yingjun Wang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Dan J Stessman
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Martin H Spalding
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa, USA
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Minagawa J, Tokutsu R. Dynamic regulation of photosynthesis in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:413-428. [PMID: 25702778 DOI: 10.1111/tpj.12805] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 02/16/2015] [Accepted: 02/18/2015] [Indexed: 05/10/2023]
Abstract
Plants and algae have acquired the ability to acclimatize to ever-changing environments to survive. During photosynthesis, light energy is converted by several membrane protein supercomplexes into electrochemical energy, which is eventually used to assimilate CO2 . The efficiency of photosynthesis is modulated by many environmental factors, including temperature, drought, CO2 concentration, and the quality and quantity of light. Recently, our understanding of such regulators of photosynthesis and the underlying molecular mechanisms has increased considerably. The photosynthetic supercomplexes undergo supramolecular reorganizations within a short time after receiving environmental cues. These reorganizations include state transitions that balance the excitation of the two photosystems: qE quenching, which thermally dissipates excess energy at the level of the light-harvesting antenna, and cyclic electron flow, which supplies the increased ATP demanded by CO2 assimilation and the pH gradient to activate qE quenching. This review focuses on the recent findings regarding the environmental regulation of photosynthesis in model organisms, paying particular attention to the unicellular green alga Chlamydomonas reinhardtii, which offer a glimpse into the dynamic behavior of photosynthetic machinery in nature.
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Affiliation(s)
- Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, Okazaki, 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, 332-0012, Japan
| | - Ryutaro Tokutsu
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
- Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies, Okazaki, 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, 332-0012, Japan
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Jia XH, Zhang PP, Shi DJ, Mi HL, Zhu JC, Huang XW, He PM. Regulation of pepc gene expression in Anabaena sp. PCC 7120 and its effects on cyclic electron flow around photosystem I and tolerances to environmental stresses. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:468-476. [PMID: 25040477 DOI: 10.1111/jipb.12241] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 07/07/2014] [Indexed: 06/03/2023]
Abstract
Since pepc gene encoding phosphoenolpyruvate carboxylase (PEPCase) has been cloned from Anabaena sp. PCC 7120 and other cyanobacteria, the effects of pepc gene expression on photosynthesis have not been reported yet. In this study, we constructed mutants containing either upregulated (forward) or downregulated (reverse) pepc gene in Anabaena sp. PCC 7120. Results from real-time quantitative polymerase chain reaction (RT-qPCR), Western blot and enzymatic analysis showed that PEPCase activity was significantly reduced in the reverse mutant compared with the wild type, and that of the forward mutant was obviously increased. Interestingly, the net photosynthesis in both the reverse mutant and the forward mutant were higher than that of the wild type, but dark respiration was decreased only in the reverse mutant. The absorbance changes of P700 upon saturation pulse showed the photosystem I (PSI) activity was inhibited, as reflected by Y(I), and Y(NA) was elevated, and dark reduction of P700(+) was stimulated, indicating enhanced cyclic electron flow (CEF) around PSI in the reverse mutant. Additionally, the reverse mutant photosynthesis was higher than that of the wild type in low temperature, low and high pH, and high salinity, and this implies increased tolerance in the reverse mutant through downregulated pepc gene.
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Affiliation(s)
- Xiao-Hui Jia
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education Shanghai, Shanghai, 201306, China
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Erickson E, Wakao S, Niyogi KK. Light stress and photoprotection in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:449-465. [PMID: 25758978 DOI: 10.1111/tpj.12825] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 03/05/2015] [Accepted: 03/06/2015] [Indexed: 05/18/2023]
Abstract
Plants and algae require light for photosynthesis, but absorption of too much light can lead to photo-oxidative damage to the photosynthetic apparatus and sustained decreases in the efficiency and rate of photosynthesis (photoinhibition). Light stress can adversely affect growth and viability, necessitating that photosynthetic organisms acclimate to different environmental conditions in order to alleviate the detrimental effects of excess light. The model unicellular green alga, Chlamydomonas reinhardtii, employs diverse strategies of regulation and photoprotection to avoid, minimize, and repair photo-oxidative damage in stressful light conditions, allowing for acclimation to different and changing environments.
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Affiliation(s)
- Erika Erickson
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Setsuko Wakao
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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48
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Abstract
Cyclic electron flow (CEF) around photosystem I is thought to balance the ATP/NADPH energy budget of photosynthesis, requiring that its rate be finely regulated. The mechanisms of this regulation are not well understood. We observed that mutants that exhibited constitutively high rates of CEF also showed elevated production of H2O2. We thus tested the hypothesis that CEF can be activated by H2O2 in vivo. CEF was strongly increased by H2O2 both by infiltration or in situ production by chloroplast-localized glycolate oxidase, implying that H2O2 can activate CEF either directly by redox modulation of key enzymes, or indirectly by affecting other photosynthetic processes. CEF appeared with a half time of about 20 min after exposure to H2O2, suggesting activation of previously expressed CEF-related machinery. H2O2-dependent CEF was not sensitive to antimycin A or loss of PGR5, indicating that increased CEF probably does not involve the PGR5-PGRL1 associated pathway. In contrast, the rise in CEF was not observed in a mutant deficient in the chloroplast NADPH:PQ reductase (NDH), supporting the involvement of this complex in CEF activated by H2O2. We propose that H2O2 is a missing link between environmental stress, metabolism, and redox regulation of CEF in higher plants.
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49
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Dubini A, Ghirardi ML. Engineering photosynthetic organisms for the production of biohydrogen. PHOTOSYNTHESIS RESEARCH 2015; 123:241-53. [PMID: 24671643 PMCID: PMC4331604 DOI: 10.1007/s11120-014-9991-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 02/17/2014] [Indexed: 05/24/2023]
Abstract
Oxygenic photosynthetic organisms such as green algae are capable of absorbing sunlight and converting the chemical energy into hydrogen gas. This process takes advantage of the photosynthetic apparatus of these organisms which links water oxidation to H2 production. Biological H2 has therefore the potential to be an alternative fuel of the future and shows great promise for generating large scale sustainable energy. Microalgae are able to produce H2 under light anoxic or dark anoxic condition by activating 3 different pathways that utilize the hydrogenases as catalysts. In this review, we highlight the principal barriers that prevent hydrogen production in green algae and how those limitations are being addressed, through metabolic and genetic engineering. We also discuss the major challenges and bottlenecks facing the development of future commercial algal photobiological systems for H2 production. Finally we provide suggestions for future strategies and potential new techniques to be developed towards an integrated system with optimized hydrogen production.
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Affiliation(s)
- Alexandra Dubini
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Mail Box 3313, Golden, CO, 80401, USA,
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50
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Clowez S, Godaux D, Cardol P, Wollman FA, Rappaport F. The involvement of hydrogen-producing and ATP-dependent NADPH-consuming pathways in setting the redox poise in the chloroplast of Chlamydomonas reinhardtii in anoxia. J Biol Chem 2015; 290:8666-76. [PMID: 25691575 DOI: 10.1074/jbc.m114.632588] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photosynthetic microalgae are exposed to changing environmental conditions. In particular, microbes found in ponds or soils often face hypoxia or even anoxia, and this severely impacts their physiology. Chlamydomonas reinhardtii is one among such photosynthetic microorganisms recognized for its unusual wealth of fermentative pathways and the extensive remodeling of its metabolism upon the switch to anaerobic conditions. As regards the photosynthetic electron transfer, this remodeling encompasses a strong limitation of the electron flow downstream of photosystem I. Here, we further characterize the origin of this limitation. We show that it stems from the strong reducing pressure that builds up upon the onset of anoxia, and this pressure can be relieved either by the light-induced synthesis of ATP, which promotes the consumption of reducing equivalents, or by the progressive activation of the hydrogenase pathway, which provides an electron transfer pathway alternative to the CO2 fixation cycle.
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Affiliation(s)
- Sophie Clowez
- From the Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 Rue P et M Curie, 75005 Paris, France, and
| | - Damien Godaux
- the Laboratoire de Génétique et Physiologie des Microalgues, Phytosystems, Department of Life Sciences, Institute of Botany, 27 Bld. du Rectorat, University of Liège, B-4000 Liège, Belgium
| | - Pierre Cardol
- the Laboratoire de Génétique et Physiologie des Microalgues, Phytosystems, Department of Life Sciences, Institute of Botany, 27 Bld. du Rectorat, University of Liège, B-4000 Liège, Belgium
| | - Francis-André Wollman
- From the Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 Rue P et M Curie, 75005 Paris, France, and
| | - Fabrice Rappaport
- From the Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 Rue P et M Curie, 75005 Paris, France, and
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