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Nanes Sarfati D, Xue Y, Song ES, Byrne A, Le D, Darmanis S, Quake SR, Burlacot A, Sikes J, Wang B. Coordinated wound responses in a regenerative animal-algal holobiont. Nat Commun 2024; 15:4032. [PMID: 38740753 DOI: 10.1038/s41467-024-48366-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
Animal regeneration involves coordinated responses across cell types throughout the animal body. In endosymbiotic animals, whether and how symbionts react to host injury and how cellular responses are integrated across species remain unexplored. Here, we study the acoel Convolutriloba longifissura, which hosts symbiotic Tetraselmis sp. green algae and can regenerate entire bodies from tissue fragments. We show that animal injury causes a decline in the photosynthetic efficiency of the symbiotic algae, alongside two distinct, sequential waves of transcriptional responses in acoel and algal cells. The initial algal response is characterized by the upregulation of a cohort of photosynthesis-related genes, though photosynthesis is not necessary for regeneration. A conserved animal transcription factor, runt, is induced after injury and required for acoel regeneration. Knockdown of Cl-runt dampens transcriptional responses in both species and further reduces algal photosynthetic efficiency post-injury. Our results suggest that the holobiont functions as an integrated unit of biological organization by coordinating molecular networks across species through the runt-dependent animal regeneration program.
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Affiliation(s)
| | - Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Eun Sun Song
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | | | - Daniel Le
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | | | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Adrien Burlacot
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - James Sikes
- Department of Biology, University of San Francisco, San Francisco, CA, USA.
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
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2
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Solhaug KA, Eiterjord G, Løken MH, Gauslaa Y. Non-photochemical quenching may contribute to the dominance of the pale mat-forming lichen Cladonia stellaris over the sympatric melanic Cetraria islandica. Oecologia 2024; 204:187-198. [PMID: 38233688 PMCID: PMC10830725 DOI: 10.1007/s00442-023-05498-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 12/10/2023] [Indexed: 01/19/2024]
Abstract
The mat-forming fruticose lichens Cladonia stellaris and Cetraria islandica frequently co-occur on soils in sun-exposed boreal, subarctic, and alpine ecosystems. While the dominant reindeer lichen Cladonia lacks a cortex but produces the light-reflecting pale pigment usnic acid on its surface, the common but patchier Cetraria has a firm cortex sealed by the light-absorbing pigment melanin. By measuring reflectance spectra, high-light tolerance, photosynthetic responses, and chlorophyll fluorescence in sympatric populations of these lichens differing in fungal pigments, we aimed to study how they cope with high light while hydrated. Specimens of the two species tolerated high light equally well but with different protective mechanisms. The mycobiont of the melanic species efficiently absorbed excess light, consistent with a lower need for its photobiont to protect itself by non-photochemical quenching (NPQ). By contrast, usnic acid screened light at 450-700 nm by reflectance and absorbed shorter wavelengths. The ecorticate usnic species with less efficient fungal light screening exhibited a consistently lower light compensation point and higher CO2 uptake rates than the melanic lichen. In both species, steady state NPQ rapidly increased at increasing light with no signs of light saturation. To compensate for less internal shading causing light fluctuations with a larger amplitude, the usnic lichen photobiont adjusted to changing light by faster induction and faster relaxation of NPQ rapidly transforming excess excitation energy to less damaging heat. The high and flexible NPQ tracking fluctuations in solar radiation probably contributes to the strong dominance of the usnic mat-forming Cladonia in open lichen-dominated heaths.
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Affiliation(s)
- Knut Asbjørn Solhaug
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432, Ås, Norway
| | - Gaute Eiterjord
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432, Ås, Norway
| | - Martine Hana Løken
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432, Ås, Norway
| | - Yngvar Gauslaa
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432, Ås, Norway.
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Shimakawa G, Matsuda Y. Extra O 2 evolution reveals an O 2-independent alternative electron sink in photosynthesis of marine diatoms. PHOTOSYNTHESIS RESEARCH 2024; 159:61-68. [PMID: 38316719 DOI: 10.1007/s11120-023-01073-3] [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: 08/31/2023] [Accepted: 12/27/2023] [Indexed: 02/07/2024]
Abstract
Following the principle of oxygenic photosynthesis, electron transport in the thylakoid membranes (i.e., light reaction) generates ATP and NADPH from light energy, which is subsequently utilized for CO2 fixation in the Calvin-Benson-Bassham cycle (i.e., dark reaction). However, light and dark reactions could discord when an alternative electron flow occurs with a rate comparable to the linear electron flow. Here, we quantitatively monitored O2 and total dissolved inorganic carbon (DIC) during photosynthesis in the pennate diatom Phaeodactylum tricornutum, and found that evolved O2 was larger than the consumption of DIC, which was consistent with 14CO2 measurements in literature. In our measurements, the stoichiometry of O2 evolution to DIC consumption was always around 1.5 during photosynthesis at different DIC concentrations. The same stoichiometry was observed in the cells grown under different CO2 concentrations and nitrogen sources except for the nitrogen-starved cells showing O2 evolution 2.5 times larger than DIC consumption. An inhibitor to nitrogen assimilation did not affect the extra O2 evolution. Further, the same physiological phenomenon was observed in the centric diatom Thalassiosira pseudonana. Based on the present dataset, we propose that the marine diatoms possess the metabolic pathway(s) functioning as the O2-independent electron sink under steady state photosynthesis that reaches nearly half of electron flux of the Calvin-Benson-Bassham cycle.
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Affiliation(s)
- Ginga Shimakawa
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo, 669-1330, Japan.
| | - Yusuke Matsuda
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo, 669-1330, Japan
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Burlacot A. Quantifying the roles of algal photosynthetic electron pathways: a milestone towards photosynthetic robustness. THE NEW PHYTOLOGIST 2023; 240:2197-2203. [PMID: 37872749 DOI: 10.1111/nph.19328] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 09/01/2023] [Indexed: 10/25/2023]
Abstract
During photosynthesis, electron transport reactions generate and shuttle reductant to allow CO2 reduction by the Calvin-Benson-Bassham cycle and the formation of biomass building block in the so-called linear electron flow (LEF). However, in nature, environmental parameters like light intensity or CO2 availability can vary and quickly change photosynthesis rates, creating an imbalance between photosynthetic energy production and metabolic needs. In addition to LEF, alternative photosynthetic electron flows are central to allow photosynthetic energy to match metabolic demand in response to environmental variations. Microalgae arguably harbour one of the most diverse set of alternative electron flows (AEFs), including cyclic (CEF), pseudocyclic (PCEF) and chloroplast-to-mitochondria (CMEF) electron flow. While CEF, PCEF and CMEF have large functional overlaps, they differ in the conditions they are active and in their role for photosynthetic energy balance. Here, I review the molecular mechanisms of CEF, PCEF and CMEF in microalgae. I further propose a quantitative framework to compare their key physiological roles and quantify how the photosynthetic energy is partitioned to maintain a balanced energetic status of the cell. Key differences in AEF within the green lineage and the potential of rewiring photosynthetic electrons to enhance plant robustness will be discussed.
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Affiliation(s)
- Adrien Burlacot
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
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5
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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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Li D, Gu B, Huang C, Shen J, Wang X, Guo J, Yu R, Mou S, Guan Q. Functional Study of Amorpha fruticosa WRKY20 Gene in Response to Drought Stress. Int J Mol Sci 2023; 24:12231. [PMID: 37569607 PMCID: PMC10418629 DOI: 10.3390/ijms241512231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023] Open
Abstract
The WRKY gene family in plants regulates the plant's response to drought through regulatory networks and hormone signaling. AfWRKY20 (MT859405) was cloned from Amorpha fruticosa (A. fruticosa) seedlings using RT-PCR. The binding properties of the AfWRKY20 protein and the W-box (a DNA cis-acting element) were verified both in vivo and in vitro using EMSA and Dual-Luciferase activity assays. RT-qPCR detected that the total expression level of AfWRKY20 in leaves and roots was 22 times higher in the 30% PEG6000 simulated drought treatment compared to the untreated group. Under the simulated drought stress treatments of sorbitol and abscisic acid (ABA), the transgenic tobacco with the AfWRKY20 gene showed enhanced drought resistance at the germination stage, with significantly increased germination rate, green leaf rate, fresh weight, and root length compared to the wild-type (WT) tobacco. In addition, the superoxide dismutase (SOD) activity, chlorophyll content, and Fv/Fm ratio of AfWRKY20 transgenic tobacco were significantly higher than those of the WT tobacco under natural drought stress, while the malondialdehyde (MDA) content and 3,3'-diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) staining levels were lower. The expression levels of oxidation kinase genes (NbSOD, NbPOD, and NbCAT) in transgenic tobacco under drought stress were significantly higher than those in WT tobacco. This enhancement in gene expression improved the ability of transgenic tobacco to detoxify reactive oxygen species (ROS). The survival rate of transgenic tobacco after natural drought rehydration was four times higher than that of WT tobacco. In summary, this study revealed the regulatory mechanism of AfWRKY20 in response to drought stress-induced ABA signaling, particularly in relation to ROS. This finding provides a theoretical basis for understanding the pathways of WRKY20 involved in drought stress, and offers genetic resources for molecular plant breeding aimed at enhancing drought resistance.
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Affiliation(s)
- Danni Li
- Key Laboratory of the Ministry of Education for Ecological Restoration of Saline Vegetation, College of Life Sciences, Northeast Forestry University, Harbin 150040, China; (D.L.)
| | - Baoxiang Gu
- Key Laboratory of the Ministry of Education for Ecological Restoration of Saline Vegetation, College of Life Sciences, Northeast Forestry University, Harbin 150040, China; (D.L.)
| | - Chunxi Huang
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China
| | - Jiayi Shen
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China
| | - Xin Wang
- Key Laboratory of the Ministry of Education for Ecological Restoration of Saline Vegetation, College of Life Sciences, Northeast Forestry University, Harbin 150040, China; (D.L.)
| | - Jianan Guo
- Key Laboratory of the Ministry of Education for Ecological Restoration of Saline Vegetation, College of Life Sciences, Northeast Forestry University, Harbin 150040, China; (D.L.)
| | - Ruiqiang Yu
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China
| | - Sirui Mou
- Key Laboratory of the Ministry of Education for Ecological Restoration of Saline Vegetation, College of Life Sciences, Northeast Forestry University, Harbin 150040, China; (D.L.)
| | - Qingjie Guan
- Key Laboratory of the Ministry of Education for Ecological Restoration of Saline Vegetation, College of Life Sciences, Northeast Forestry University, Harbin 150040, China; (D.L.)
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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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8
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Bag P, Shutova T, Shevela D, Lihavainen J, Nanda S, Ivanov AG, Messinger J, Jansson S. Flavodiiron-mediated O 2 photoreduction at photosystem I acceptor-side provides photoprotection to conifer thylakoids in early spring. Nat Commun 2023; 14:3210. [PMID: 37270605 DOI: 10.1038/s41467-023-38938-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 05/23/2023] [Indexed: 06/05/2023] Open
Abstract
Green organisms evolve oxygen (O2) via photosynthesis and consume it by respiration. Generally, net O2 consumption only becomes dominant when photosynthesis is suppressed at night. Here, we show that green thylakoid membranes of Scots pine (Pinus sylvestris L) and Norway spruce (Picea abies) needles display strong O2 consumption even in the presence of light when extremely low temperatures coincide with high solar irradiation during early spring (ES). By employing different electron transport chain inhibitors, we show that this unusual light-induced O2 consumption occurs around photosystem (PS) I and correlates with higher abundance of flavodiiron (Flv) A protein in ES thylakoids. With P700 absorption changes, we demonstrate that electron scavenging from the acceptor-side of PSI via O2 photoreduction is a major alternative pathway in ES. This photoprotection mechanism in vascular plants indicates that conifers have developed an adaptative evolution trajectory for growing in harsh environments.
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Affiliation(s)
- Pushan Bag
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
- Section of Molecular Plant Biology, Department of Biology, University of Oxford, Oxford, UK
| | - Tatyana Shutova
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Dmitry Shevela
- Department of Chemistry, Chemical Biological Centre, Umeå University, Umeå, Sweden
| | - Jenna Lihavainen
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Sanchali Nanda
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Alexander G Ivanov
- Department of Biology, University of Western Ontario, London, ON, Canada
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Johannes Messinger
- Department of Chemistry, Chemical Biological Centre, Umeå University, Umeå, Sweden
- Department of Chemistry-Ångström laboratory, Uppsala University, Uppsala, Sweden
| | - Stefan Jansson
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.
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Saroussi S, Redekop P, Karns DAJ, Thomas DC, Wittkopp TM, Posewitz MC, Grossman AR. Restricting electron flow at cytochrome b6f when downstream electron acceptors are severely limited. PLANT PHYSIOLOGY 2023; 192:789-804. [PMID: 36960590 PMCID: PMC10231464 DOI: 10.1093/plphys/kiad185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 06/01/2023]
Abstract
Photosynthetic organisms frequently experience abiotic stress that restricts their growth and development. Under such circumstances, most absorbed solar energy cannot be used for CO2 fixation and can cause the photoproduction of reactive oxygen species (ROS) that can damage the photosynthetic reaction centers of PSI and PSII, resulting in a decline in primary productivity. This work describes a biological "switch" in the green alga Chlamydomonas reinhardtii that reversibly restricts photosynthetic electron transport (PET) at the cytochrome b6f (Cyt b6f) complex when the capacity for accepting electrons downstream of PSI is severely limited. We specifically show this restriction in STARCHLESS6 (sta6) mutant cells, which cannot synthesize starch when they are limited for nitrogen (growth inhibition) and subjected to a dark-to-light transition. This restriction represents a form of photosynthetic control that causes diminished electron flow to PSI and thereby prevents PSI photodamage but does not appear to rely on a ΔpH. Furthermore, when electron flow is restricted, the plastid alternative oxidase (PTOX) becomes active, functioning as an electron valve that dissipates some excitation energy absorbed by PSII and allows the formation of a proton motive force (PMF) that would drive some ATP production (potentially sustaining PSII repair and nonphotochemical quenching [NPQ]). The restriction at the Cyt b6f complex can be gradually relieved with continued illumination. This study provides insights into how PET responds to a marked reduction in availability of downstream electron acceptors and the protective mechanisms involved.
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Affiliation(s)
- Shai Saroussi
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Petra Redekop
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Devin A J Karns
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Dylan C Thomas
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Tyler M Wittkopp
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Matthew C Posewitz
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Arthur R Grossman
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA 94305, USA
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Huang W, Krishnan A, Plett A, Meagher M, Linka N, Wang Y, Ren B, Findinier J, Redekop P, Fakhimi N, Kim RG, Karns DA, Boyle N, Posewitz MC, Grossman AR. Chlamydomonas mutants lacking chloroplast TRIOSE PHOSPHATE TRANSPORTER3 are metabolically compromised and light-sensitive. THE PLANT CELL 2023:koad095. [PMID: 36970811 DOI: 10.1093/plcell/koad095] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/08/2023] [Accepted: 03/23/2023] [Indexed: 06/18/2023]
Abstract
Modulation of photoassimilate export from the chloroplast is essential for controlling the distribution of fixed carbon in the cell and maintaining optimum photosynthetic rates. In this study we identified chloroplast TRIOSE PHOSPHATE/PHOSPHATE TRANSLOCATOR2 (CreTPT2) and CreTPT3 in the green alga Chlamydomonas (Chlamydomonas reinhardtii), which exhibit similar substrate specificities but whose encoding genes are differentially expressed over the diurnal cycle. We focused mostly on CreTPT3 because of its high level of expression and the severe phenotype exhibited by tpt3 relative to tpt2 mutants. Null mutants for CreTPT3 had a pleiotropic phenotype that affected growth, photosynthetic activities, metabolite profiles, carbon partitioning, and organelle-specific accumulation of H2O2. These analyses demonstrated that CreTPT3 is a dominant conduit on the chloroplast envelope for the transport of photoassimilates. In addition, CreTPT3 can serve as a safety valve that moves excess reductant out of the chloroplast and appears to be essential for preventing cells from experiencing oxidative stress and accumulating reactive oxygen species, even under low/moderate light intensities. Finally, our studies indicate subfunctionalization of the CreTPT transporters and suggest that there are differences in managing the export of photoassimilates from the chloroplasts of Chlamydomonas and vascular plants.
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Affiliation(s)
- Weichao Huang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Anagha Krishnan
- Department of Chemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Anastasija Plett
- Institute of Plant Biochemistry, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Michelle Meagher
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Nicole Linka
- Institute of Plant Biochemistry, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Yongsheng Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
- School of Life Sciences, Tsinghua University, 100084 Beijing, China
| | - Bijie Ren
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Justin Findinier
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Petra Redekop
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Neda Fakhimi
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Rick G Kim
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Devin A Karns
- Department of Chemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Nanette Boyle
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Matthew C Posewitz
- Department of Chemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
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11
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Santana‐Sánchez A, Nikkanen L, Werner E, Tóth G, Ermakova M, Kosourov S, Walter J, He M, Aro E, Allahverdiyeva Y. Flv3A facilitates O 2 photoreduction and affects H 2 photoproduction independently of Flv1A in diazotrophic Anabaena filaments. THE NEW PHYTOLOGIST 2023; 237:126-139. [PMID: 36128660 PMCID: PMC10092803 DOI: 10.1111/nph.18506] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 09/10/2022] [Indexed: 05/23/2023]
Abstract
The model heterocyst-forming filamentous cyanobacterium Anabaena sp. PCC 7120 (Anabaena) is a typical example of a multicellular organism capable of simultaneously performing oxygenic photosynthesis in vegetative cells and O2 -sensitive N2 -fixation inside heterocysts. The flavodiiron proteins have been shown to participate in photoprotection of photosynthesis by driving excess electrons to O2 (a Mehler-like reaction). Here, we performed a phenotypic and biophysical characterization of Anabaena mutants impaired in vegetative-specific Flv1A and Flv3A in order to address their physiological relevance in the bioenergetic processes occurring in diazotrophic Anabaena under variable CO2 conditions. We demonstrate that both Flv1A and Flv3A are required for proper induction of the Mehler-like reaction upon a sudden increase in light intensity, which is likely important for the activation of carbon-concentrating mechanisms and CO2 fixation. Under ambient CO2 diazotrophic conditions, Flv3A is responsible for moderate O2 photoreduction, independently of Flv1A, but only in the presence of Flv2 and Flv4. Strikingly, the lack of Flv3A resulted in strong downregulation of the heterocyst-specific uptake hydrogenase, which led to enhanced H2 photoproduction under both oxic and micro-oxic conditions. These results reveal a novel regulatory network between the Mehler-like reaction and the diazotrophic metabolism, which is of great interest for future biotechnological applications.
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Affiliation(s)
- Anita Santana‐Sánchez
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Lauri Nikkanen
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Elisa Werner
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Gábor Tóth
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Maria Ermakova
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Sergey Kosourov
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Julia Walter
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Meilin He
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Eva‐Mari Aro
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
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12
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Böhmer S, Marx C, Goss R, Gilbert M, Sasso S, Happe T, Hemschemeier A. Chlamydomonas reinhardtii mutants deficient for Old Yellow Enzyme 3 exhibit increased photooxidative stress. PLANT DIRECT 2023; 7:e480. [PMID: 36685735 PMCID: PMC9840898 DOI: 10.1002/pld3.480] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 11/14/2022] [Accepted: 12/31/2022] [Indexed: 05/12/2023]
Abstract
Old Yellow Enzymes (OYEs) are flavin-containing ene-reductases that have been intensely studied with regard to their biotechnological potential for sustainable chemical syntheses. OYE-encoding genes are found throughout the domains of life, but their physiological role is mostly unknown, one reason for this being the promiscuity of most ene-reductases studied to date. The unicellular green alga Chlamydomonas reinhardtii possesses four genes coding for OYEs, three of which we have analyzed biochemically before. Ene-reductase CrOYE3 stood out in that it showed an unusually narrow substrate scope and converted N-methylmaleimide (NMI) with high rates. This was recapitulated in a C. reinhardtii croye3 mutant that, in contrast to the wild type, hardly degraded externally added NMI. Here we show that CrOYE3-mediated NMI conversion depends on electrons generated photosynthetically by photosystem II (PSII) and that the croye3 mutant exhibits slightly decreased photochemical quenching in high light. Non-photochemical quenching is strongly impaired in this mutant, and it shows enhanced oxidative stress. The phenotypes of the mutant suggest that C. reinhardtii CrOYE3 is involved in the protection against photooxidative stress, possibly by converting reactive carbonyl species derived from lipid peroxides or maleimides from tetrapyrrole degradation.
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Affiliation(s)
- Stefanie Böhmer
- Faculty of Biology and Biotechnology, PhotobiotechnologyRuhr University BochumBochumGermany
| | - Christina Marx
- SolarBioproducts RuhrBusiness Development Agency HerneHerneGermany
| | - Reimund Goss
- Institute of Biology, Plant PhysiologyLeipzig UniversityLeipzigGermany
| | - Matthias Gilbert
- Institute of Biology, Plant PhysiologyLeipzig UniversityLeipzigGermany
| | - Severin Sasso
- Institute of Biology, Plant PhysiologyLeipzig UniversityLeipzigGermany
| | - Thomas Happe
- Faculty of Biology and Biotechnology, PhotobiotechnologyRuhr University BochumBochumGermany
| | - Anja Hemschemeier
- Faculty of Biology and Biotechnology, PhotobiotechnologyRuhr University BochumBochumGermany
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13
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Obara A, Ogawa M, Oyama Y, Suzuki Y, Kono M. Effects of High Irradiance and Low Water Temperature on Photoinhibition and Repair of Photosystems in Marimo ( Aegagropila linnaei) in Lake Akan, Japan. Int J Mol Sci 2022; 24:ijms24010060. [PMID: 36613526 PMCID: PMC9820325 DOI: 10.3390/ijms24010060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
The green alga Aegagropila linnaei often forms spherical aggregates called "marimo" in Lake Akan in Japan. In winter, marimo are exposed to low water temperatures at 1-4 °C but protected from strong sunlight by ice coverage, which may disappear due to global warming. In this study, photoinhibition in marimo was examined at 2 °C using chlorophyll fluorescence and 830 nm absorption. Filamentous cells of A. linnaei dissected from marimo were exposed to strong light at 2 °C. Photosystem II (PSII) was markedly photoinhibited, while photosystem I was unaffected. When the cells with PSII damaged by the 4 h treatment were subsequently illuminated with moderate repair light at 2 °C, the maximal efficiency of PSII was recovered to the level before photoinhibition. However, after the longer photoinhibitory treatments, PSII efficiency did not recover by the repair light. When the cells were exposed to simulated diurnal light for 12 h per day, which was more ecological, the cells died within a few days. Our results showed new findings of the PSII repair at 2 °C and serious damage at the cellular level from prolonged high-light treatments. Further, we provided a clue to what may happen to marimo in Lake Akan in the near future.
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Affiliation(s)
- Akina Obara
- Department of Biological Sciences, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Kanagawa, Hiratsuka 259-1293, Japan
| | - Mari Ogawa
- Department of Primary Education, Faculty of Education, Yasuda Women’s University, 6-13-1 Yasuhigashi, Asaminami-ku, Hiroshima 731-0153, Japan
| | - Yoichi Oyama
- Marimo Research Center, Kushiro Board of Education, Hokkaido, Kushiro 085-0467, Japan
| | - Yoshihiro Suzuki
- Department of Biological Sciences, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Kanagawa, Hiratsuka 259-1293, Japan
| | - Masaru Kono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-0033, Japan
- Correspondence: ; Tel.: +81-3-5841-4467; Fax: +81-3-5841-4465
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14
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Tan YH, Poong SW, Yang CH, Lim PE, John B, Pai TW, Phang SM. Transcriptomic analysis reveals distinct mechanisms of adaptation of a polar picophytoplankter under ocean acidification conditions. MARINE ENVIRONMENTAL RESEARCH 2022; 182:105782. [PMID: 36308800 DOI: 10.1016/j.marenvres.2022.105782] [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: 06/17/2022] [Revised: 10/12/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
Human emissions of carbon dioxide are causing irreversible changes in our oceans and impacting marine phytoplankton, including a group of small green algae known as picochlorophytes. Picochlorophytes grown in natural phytoplankton communities under future predicted levels of carbon dioxide have been demonstrated to thrive, along with redistribution of the cellular metabolome that enhances growth rate and photosynthesis. Here, using next-generation sequencing technology, we measured levels of transcripts in a picochlorophyte Chlorella, isolated from the sub-Antarctic and acclimated under high and current ambient CO2 levels, to better understand the molecular mechanisms involved with its ability to acclimate to elevated CO2. Compared to other phytoplankton taxa that induce broad transcriptomic responses involving multiple parts of their cellular metabolism, the changes observed in Chlorella focused on activating gene regulation involved in different sets of pathways such as light harvesting complex binding proteins, amino acid synthesis and RNA modification, while carbon metabolism was largely unaffected. Triggering a specific set of genes could be a unique strategy of small green phytoplankton under high CO2 in polar oceans.
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Affiliation(s)
- Yong-Hao Tan
- Institute for Advanced Studies, University of Malaya, Kuala Lumpur, Malaysia; Institute of Ocean & Earth Sciences, University of Malaya, Kuala Lumpur, Malaysia
| | - Sze-Wan Poong
- Institute of Ocean & Earth Sciences, University of Malaya, Kuala Lumpur, Malaysia
| | - Cing-Han Yang
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
| | - Phaik-Eem Lim
- Institute of Ocean & Earth Sciences, University of Malaya, Kuala Lumpur, Malaysia.
| | - Beardall John
- School of Biological Sciences, Monash University, Clayton, Australia
| | - Tun-Wen Pai
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan; Department of Computer Science and Information Engineering, National Taipei University of Technology, Taipei, Taiwan
| | - Siew-Moi Phang
- Institute of Ocean & Earth Sciences, University of Malaya, Kuala Lumpur, Malaysia; Department of Biotechnology, Faculty of Applied Science, UCSI University, Kuala Lumpur, Malaysia; The Chancellery, UCSI University, Kuala Lumpur, Malaysia
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15
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Zhou L, Gao S, Yang W, Wu S, Huan L, Xie X, Wang X, Lin S, Wang G. Transcriptomic and metabolic signatures of diatom plasticity to light fluctuations. PLANT PHYSIOLOGY 2022; 190:2295-2314. [PMID: 36149329 PMCID: PMC9706478 DOI: 10.1093/plphys/kiac455] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/09/2022] [Indexed: 06/01/2023]
Abstract
Unlike in terrestrial and freshwater ecosystems, light fields in oceans fluctuate due to both horizontal current and vertical mixing. Diatoms thrive and dominate the phytoplankton community in these fluctuating light fields. However, the molecular mechanisms that regulate diatom acclimation and adaptation to light fluctuations are poorly understood. Here, we performed transcriptome sequencing, metabolome profiling, and 13C-tracer labeling on the model diatom Phaeodactylum tricornutum. The diatom acclimated to constant light conditions was transferred to six different light conditions, including constant light (CL5d), short-term (1 h) high light (sHL1h), and short-term (1 h) and long-term (5 days) mild or severe light fluctuation conditions (mFL1h, sFL1h, mFL5d, and sFL5d) that mimicked land and ocean light levels. We identified 2,673 transcripts (25% of the total expressed genes) expressed differentially under different fluctuating light regimes. We also identified 497 transcription factors, 228 not reported previously, which exhibited higher expression under light fluctuations, including 7 with a light-sensitive PAS domain (Per-period circadian protein, Arnt-aryl hydrocarbon receptor nuclear translocator protein, Sim-single-minded protein) and 10 predicted to regulate genes related to light-harvesting complex proteins. Our data showed that prolonged preconditioning in severe light fluctuation enhanced photosynthesis in P. tricornutum under this condition, as evidenced by increased oxygen evolution accompanied by the upregulation of Rubisco and light-harvesting proteins. Furthermore, severe light fluctuation diverted the metabolic flux of assimilated carbon preferentially toward fatty acid storage over sugar and protein. Our results suggest that P. tricornutum use a series of complex and different responsive schemes in photosynthesis and carbon metabolism to optimize their growth under mild and severe light fluctuations. These insights underscore the importance of using more intense conditions when investigating the resilience of phytoplankton to light fluctuations.
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Affiliation(s)
- Lu Zhou
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shan Gao
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Wenting Yang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Songcui Wu
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Li Huan
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xiujun Xie
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xulei Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, Connecticut, USA
| | - Guangce Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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16
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Pokora W, Tułodziecki S, Dettlaff-Pokora A, Aksmann A. Cross Talk between Hydrogen Peroxide and Nitric Oxide in the Unicellular Green Algae Cell Cycle: How Does It Work? Cells 2022; 11:cells11152425. [PMID: 35954269 PMCID: PMC9368121 DOI: 10.3390/cells11152425] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/22/2022] [Accepted: 08/03/2022] [Indexed: 11/22/2022] Open
Abstract
The regulatory role of some reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as hydrogen peroxide or nitric oxide, has been demonstrated in some higher plants and algae. Their involvement in regulation of the organism, tissue and single cell development can also be seen in many animals. In green cells, the redox potential is an important photosynthesis regulatory factor that may lead to an increase or decrease in growth rate. ROS and RNS are important signals involved in the regulation of photoautotrophic growth that, in turn, allow the cell to attain the commitment competence. Both hydrogen peroxide and nitric oxide are directly involved in algal cell development as the signals that regulate expression of proteins required for completing the cell cycle, such as cyclins and cyclin-dependent kinases, or histone proteins and E2F complex proteins. Such regulation seems to relate to the direct interaction of these signaling molecules with the redox-sensitive transcription factors, but also with regulation of signaling pathways including MAPK, G-protein and calmodulin-dependent pathways. In this paper, we aim to elucidate the involvement of hydrogen peroxide and nitric oxide in algal cell cycle regulation, considering the role of these molecules in higher plants. We also evaluate the commercial applicability of this knowledge. The creation of a simple tool, such as a precisely established modification of hydrogen peroxide and/or nitric oxide at the cellular level, leading to changes in the ROS-RNS cross-talk network, can be used for the optimization of the efficiency of algal cell growth and may be especially important in the context of increasing the role of algal biomass in science and industry. It could be a part of an important scientific challenge that biotechnology is currently focused on.
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Affiliation(s)
- Wojciech Pokora
- Department of Plant Physiology and Biotechnology, Faculty of Biology, University of Gdańsk Wita, Stwosza 59, 83-308 Gdańsk, Poland
- Correspondence:
| | - Szymon Tułodziecki
- Department of Plant Physiology and Biotechnology, Faculty of Biology, University of Gdańsk Wita, Stwosza 59, 83-308 Gdańsk, Poland
| | | | - Anna Aksmann
- Department of Plant Physiology and Biotechnology, Faculty of Biology, University of Gdańsk Wita, Stwosza 59, 83-308 Gdańsk, Poland
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17
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Dao O, Kuhnert F, Weber APM, Peltier G, Li-Beisson Y. Physiological functions of malate shuttles in plants and algae. TRENDS IN PLANT SCIENCE 2022; 27:488-501. [PMID: 34848143 DOI: 10.1016/j.tplants.2021.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
Subcellular compartmentalization confers evolutionary advantage to eukaryotic cells but entails the need for efficient interorganelle communication. Malate functions as redox carrier and metabolic intermediate. It can be shuttled across membranes through translocators. The interconversion of malate and oxaloacetate mediated by malate dehydrogenases requires oxidation/reduction of NAD(P)H/NAD(P)+; therefore, malate trafficking serves to transport reducing equivalents and this is termed the 'malate shuttle'. Although the term 'malate shuttle' was coined more than 50 years ago, novel functions are still emerging. This review highlights recent findings on the functions of malate shuttles in photorespiration, fatty acid β-oxidation, interorganelle signaling and its putative role in CO2-concentrating mechanisms. We compare and contrast knowledge in plants and algae, thereby providing an evolutionary perspective on redox trafficking in photosynthetic eukaryotes.
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Affiliation(s)
- Ousmane Dao
- Aix Marseille Univ, CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint Paul-Lez-Durance 13108, France
| | - Franziska Kuhnert
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Science (CEPLAS), Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Andreas P M Weber
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Science (CEPLAS), Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint Paul-Lez-Durance 13108, France
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint Paul-Lez-Durance 13108, France.
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18
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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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19
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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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20
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Regulation of the generation of reactive oxygen species during photosynthetic electron transport. Biochem Soc Trans 2022; 50:1025-1034. [PMID: 35437580 DOI: 10.1042/bst20211246] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 11/17/2022]
Abstract
Light capture by chlorophylls and photosynthetic electron transport bury the risk of the generation of reactive oxygen species (ROS) including singlet oxygen, superoxide anion radicals and hydrogen peroxide. Rapid changes in light intensity, electron fluxes and accumulation of strong oxidants and reductants increase ROS production. Superoxide is mainly generated at the level of photosystem I while photosystem II is the main source of singlet oxygen. ROS can induce oxidative damage of the photosynthetic apparatus, however, ROS are also important to tune processes inside the chloroplast and participate in retrograde signalling regulating the expression of genes involved in acclimation responses. Under most physiological conditions light harvesting and photosynthetic electron transport are regulated to keep the level of ROS at a non-destructive level. Photosystem II is most prone to photoinhibition but can be quickly repaired while photosystem I is protected in most cases. The size of the transmembrane proton gradient is central for the onset of mechanisms that protect against photoinhibition. The proton gradient allows dissipation of excess energy as heat in the antenna systems and it regulates electron transport. pH-dependent slowing down of electron donation to photosystem I protects it against ROS generation and damage. Cyclic electron transfer and photoreduction of oxygen contribute to the size of the proton gradient. The yield of singlet oxygen production in photosystem II is regulated by changes in the midpoint potential of its primary quinone acceptor. In addition, numerous antioxidants inside the photosystems, the antenna and the thylakoid membrane quench or scavenge ROS.
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21
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Zhang N, Pazouki L, Nguyen H, Jacobshagen S, Bigge BM, Xia M, Mattoon EM, Klebanovych A, Sorkin M, Nusinow DA, Avasthi P, Czymmek KJ, Zhang R. Comparative Phenotyping of Two Commonly Used Chlamydomonas reinhardtii Background Strains: CC-1690 (21gr) and CC-5325 (The CLiP Mutant Library Background). PLANTS (BASEL, SWITZERLAND) 2022; 11:585. [PMID: 35270055 PMCID: PMC8912731 DOI: 10.3390/plants11050585] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 05/02/2023]
Abstract
The unicellular green alga Chlamydomonas reinhardtii is an excellent model organism to investigate many essential cellular processes in photosynthetic eukaryotes. Two commonly used background strains of Chlamydomonas are CC-1690 and CC-5325. CC-1690, also called 21gr, has been used for the Chlamydomonas genome project and several transcriptome analyses. CC-5325 is the background strain for the Chlamydomonas Library Project (CLiP). Photosynthetic performance in CC-5325 has not been evaluated in comparison with CC-1690. Additionally, CC-5325 is often considered to be cell-wall deficient, although detailed analysis is missing. The circadian rhythms in CC-5325 are also unclear. To fill these knowledge gaps and facilitate the use of the CLiP mutant library for various screens, we performed phenotypic comparisons between CC-1690 and CC-5325. Our results showed that CC-5325 grew faster heterotrophically in dark and equally well in mixotrophic liquid medium as compared to CC-1690. CC-5325 had lower photosynthetic efficiency and was more heat-sensitive than CC-1690. Furthermore, CC-5325 had an intact cell wall which had comparable integrity to that in CC-1690 but appeared to have reduced thickness. Additionally, CC-5325 could perform phototaxis, but could not maintain a sustained circadian rhythm of phototaxis as CC1690 did. Finally, in comparison to CC-1690, CC-5325 had longer cilia in the medium with acetate but slower swimming speed in the medium without nitrogen and acetate. Our results will be useful for researchers in the Chlamydomonas community to choose suitable background strains for mutant analysis and employ the CLiP mutant library for genome-wide mutant screens under appropriate conditions, especially in the areas of photosynthesis, thermotolerance, cell wall, and circadian rhythms.
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Affiliation(s)
- Ningning Zhang
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Leila Pazouki
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Huong Nguyen
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Sigrid Jacobshagen
- Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA;
| | - Brae M. Bigge
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (B.M.B.); (P.A.)
| | - Ming Xia
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Erin M. Mattoon
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
- Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, MO 63130, USA
| | - Anastasiya Klebanovych
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Maria Sorkin
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
- Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, MO 63130, USA
| | - Dmitri A. Nusinow
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Prachee Avasthi
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (B.M.B.); (P.A.)
| | - Kirk J. Czymmek
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Ru Zhang
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
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22
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Yang YJ, Shi Q, Sun H, Mei RQ, Huang W. Differential Response of the Photosynthetic Machinery to Fluctuating Light in Mature and Young Leaves of Dendrobium officinale. FRONTIERS IN PLANT SCIENCE 2022; 12:829783. [PMID: 35185969 PMCID: PMC8850366 DOI: 10.3389/fpls.2021.829783] [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: 12/06/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
A key component of photosynthetic electron transport chain, photosystem I (PSI), is susceptible to the fluctuating light (FL) in angiosperms. Cyclic electron flow (CEF) around PSI and water-water cycle (WWC) are both used by the epiphytic orchid Dendrobium officinale to protect PSI under FL. This study examined whether the ontogenetic stage of leaf has an impact on the photoprotective mechanisms dealing with FL. Thus, chlorophyll fluorescence and P700 signals under FL were measured in D. officinale young and mature leaves. Upon transition from dark to actinic light, a rapid re-oxidation of P700 was observed in mature leaves but disappeared in young leaves, indicating that WWC existed in mature leaves but was lacking in young leaves. After shifting from low to high light, PSI over-reduction was clearly missing in mature leaves. By comparison, young leaves showed a transient PSI over-reduction within the first 30 s, which was accompanied with highly activation of CEF. Therefore, the effect of FL on PSI redox state depends on the leaf ontogenetic stage. In mature leaves, WWC is employed to avoid PSI over-reduction. In young leaves, CEF around PSI is enhanced to compensate for the lack of WWC and thus to prevent an uncontrolled PSI over-reduction induced by FL.
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Affiliation(s)
- Ying-Jie Yang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Qi Shi
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hu Sun
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ren-Qiang Mei
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Bio-Innovation Center of DR PLANT, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
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23
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Choi BY, Kim H, Shim D, Jang S, Yamaoka Y, Shin S, Yamano T, Kajikawa M, Jin E, Fukuzawa H, Lee Y. The Chlamydomonas bZIP transcription factor BLZ8 confers oxidative stress tolerance by inducing the carbon-concentrating mechanism. THE PLANT CELL 2022; 34:910-926. [PMID: 34893905 PMCID: PMC8824676 DOI: 10.1093/plcell/koab293] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/28/2021] [Indexed: 05/19/2023]
Abstract
Photosynthetic organisms are exposed to various environmental sources of oxidative stress. Land plants have diverse mechanisms to withstand oxidative stress, but how microalgae do so remains unclear. Here, we characterized the Chlamydomonas reinhardtii basic leucine zipper (bZIP) transcription factor BLZ8, which is highly induced by oxidative stress. Oxidative stress tolerance increased with increasing BLZ8 expression levels. BLZ8 regulated the expression of genes likely involved in the carbon-concentrating mechanism (CCM): HIGH-LIGHT ACTIVATED 3 (HLA3), CARBONIC ANHYDRASE 7 (CAH7), and CARBONIC ANHYDRASE 8 (CAH8). BLZ8 expression increased the photosynthetic affinity for inorganic carbon under alkaline stress conditions, suggesting that BLZ8 induces the CCM. BLZ8 expression also increased the photosynthetic linear electron transfer rate, reducing the excitation pressure of the photosynthetic electron transport chain and in turn suppressing reactive oxygen species (ROS) production under oxidative stress conditions. A carbonic anhydrase inhibitor, ethoxzolamide, abolished the enhanced tolerance to alkaline stress conferred by BLZ8 overexpression. BLZ8 directly regulated the expression of the three target genes and required bZIP2 as a dimerization partner in activating CAH8 and HLA3. Our results suggest that a CCM-mediated increase in the CO2 supply for photosynthesis is critical to minimize oxidative damage in microalgae, since slow gas diffusion in aqueous environments limits CO2 availability for photosynthesis, which can trigger ROS formation.
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Affiliation(s)
| | | | - Donghwan Shim
- Department of Biological Sciences, Chungnam National University, Daejeon 34134 Korea
| | - Sunghoon Jang
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | | | - Seungjun Shin
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | | | - EonSeon Jin
- Department of Life Science, Hanyang University, Seoul 133-791, South Korea
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24
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Zeng ZL, Sun H, Wang XQ, Zhang SB, Huang W. Regulation of Leaf Angle Protects Photosystem I under Fluctuating Light in Tobacco Young Leaves. Cells 2022; 11:252. [PMID: 35053368 PMCID: PMC8773500 DOI: 10.3390/cells11020252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 12/31/2021] [Accepted: 01/04/2022] [Indexed: 02/05/2023] Open
Abstract
Fluctuating light is a typical light condition in nature and can cause selective photodamage to photosystem I (PSI). The sensitivity of PSI to fluctuating light is influenced by the amplitude of low/high light intensity. Tobacco mature leaves are tended to be horizontal to maximize the light absorption and photosynthesis, but young leaves are usually vertical to diminish the light absorption. Therefore, we tested the hypothesis that such regulation of the leaf angle in young leaves might protect PSI against photoinhibition under fluctuating light. We found that, upon a sudden increase in illumination, PSI was over-reduced in extreme young leaves but was oxidized in mature leaves. After fluctuating light treatment, such PSI over-reduction aggravated PSI photoinhibition in young leaves. Furthermore, the leaf angle was tightly correlated to the extent of PSI photoinhibition induced by fluctuating light. Therefore, vertical young leaves are more susceptible to PSI photoinhibition than horizontal mature leaves when exposed to the same fluctuating light. In young leaves, the vertical leaf angle decreased the light absorption and thus lowered the amplitude of low/high light intensity. Therefore, the regulation of the leaf angle was found for the first time as an important strategy used by young leaves to protect PSI against photoinhibition under fluctuating light. To our knowledge, we show here new insight into the photoprotection for PSI under fluctuating light in nature.
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Affiliation(s)
- Zhi-Lan Zeng
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hu Sun
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Qian Wang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
| | - Shi-Bao Zhang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
| | - Wei Huang
- Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; (Z.-L.Z.); (H.S.); (X.-Q.W.); (S.-B.Z.)
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25
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Shimakawa G, Shoguchi E, Burlacot A, Ifuku K, Che Y, Kumazawa M, Tanaka K, Nakanishi S. Coral symbionts evolved a functional polycistronic flavodiiron gene. PHOTOSYNTHESIS RESEARCH 2022; 151:113-124. [PMID: 34309771 DOI: 10.1007/s11120-021-00867-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/17/2021] [Indexed: 05/26/2023]
Abstract
Photosynthesis in cyanobacteria, green algae, and basal land plants is protected against excess reducing pressure on the photosynthetic chain by flavodiiron proteins (FLV) that dissipate photosynthetic electrons by reducing O2. In these organisms, the genes encoding FLV are always conserved in the form of a pair of two-type isozymes (FLVA and FLVB) that are believed to function in O2 photo-reduction as a heterodimer. While coral symbionts (dinoflagellates of the family Symbiodiniaceae) are the only algae to harbor FLV in photosynthetic red plastid lineage, only one gene is found in transcriptomes and its role and activity remain unknown. Here, we characterized the FLV genes in Symbiodiniaceae and found that its coding region is composed of tandemly repeated FLV sequences. By measuring the O2-dependent electron flow and P700 oxidation, we suggest that this atypical FLV is active in vivo. Based on the amino-acid sequence alignment and the phylogenetic analysis, we conclude that in coral symbionts, the gene pair for FLVA and FLVB have been fused to construct one coding region for a hybrid enzyme, which presumably occurred when or after both genes were inherited from basal green algae to the dinoflagellate. Immunodetection suggested the FLV polypeptide to be cleaved by a post-translational mechanism, adding it to the rare cases of polycistronic genes in eukaryotes. Our results demonstrate that FLV are active in coral symbionts with genomic arrangement that is unique to these species. The implication of these unique features on their symbiotic living environment is discussed.
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Affiliation(s)
- Ginga Shimakawa
- Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan.
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Adrien Burlacot
- Aix Marseille University, CEA, CNRS, Institut de Biosciences Et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, 111 Koshland Hall, Berkeley, CA, 94720-3102, USA
| | - Kentaro Ifuku
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Yufen Che
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Minoru Kumazawa
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | - Kenya Tanaka
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8631, Japan
| | - Shuji Nakanishi
- Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka, 560-8631, Japan
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26
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Gao S, Pinnola A, Zhou L, Zheng Z, Li Z, Bassi R, Wang G. Light-harvesting complex stress-related proteins play crucial roles in the acclimation of Physcomitrella patens under fluctuating light conditions. PHOTOSYNTHESIS RESEARCH 2022; 151:1-10. [PMID: 34468919 DOI: 10.1007/s11120-021-00874-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Photosynthetic organisms have evolved photoprotective mechanisms to acclimate to light intensity fluctuations in their natural growth environments. Photosystem (PS) II subunit S (PsbS) and light-harvesting complex (LHC) stress-related proteins (LhcSR) are essential for triggering photoprotection in vascular plants and green algae, respectively. The activity of both proteins is strongly enhanced in the moss Physcomitrella patens under high-light conditions. However, their role in regulating photosynthesis acclimation in P. patens under fluctuating light (FL) conditions is still unknown. Here, we compare the responses of wild-type (WT) P. patens and mutants lacking PsbS (psbs KO) or LhcSR1 and 2 (lhcsr KO) to FL conditions in which the low-light phases were periodically interrupted with high-light pulses. lhcsr KO mutant showed a strong reduction in growth with respect to WT and psbs KO under FL conditions. The lack of LhcSR not only decreased the level of non-photochemical quenching, resulting in an over-reduced plastoquinone pool, but also significantly increased the PSI acceptor limitation values with respect to WT and psbs KO under FL conditions. Moreover, in lhcsr KO mutant, the abundance of PSI core and PSI-LHCI complex decreased greatly under FL conditions compared with the WT and psbs KO. We proposed that LhcSR in P. patens play a crucial role in moss acclimation to dynamic light changes.
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Affiliation(s)
- Shan Gao
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Alberta Pinnola
- Department of Biology and Biotechnology 'L. Spallanzani'(DBB), University of Pavia, Pavia, Italy
| | - Lu Zhou
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhenbing Zheng
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhuangyue Li
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, USA
| | - Roberto Bassi
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Guangce Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
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27
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Serrano-Pérez E, Romero-Losada AB, Morales-Pineda M, García-Gómez ME, Couso I, García-González M, Romero-Campero FJ. Transcriptomic and Metabolomic Response to High Light in the Charophyte Alga Klebsormidium nitens. FRONTIERS IN PLANT SCIENCE 2022; 13:855243. [PMID: 35599877 PMCID: PMC9121098 DOI: 10.3389/fpls.2022.855243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/28/2022] [Indexed: 05/04/2023]
Abstract
The characterization of the molecular mechanisms, such as high light irradiance resistance, that allowed plant terrestralization is a cornerstone in evolutionary studies since the conquest of land by plants played a pivotal role in life evolution on Earth. Viridiplantae or the green lineage is divided into two clades, Chlorophyta and Streptophyta, that in turn splits into Embryophyta or land plants and Charophyta. Charophyta are used in evolutionary studies on plant terrestralization since they are generally accepted as the extant algal species most closely related to current land plants. In this study, we have chosen the facultative terrestrial early charophyte alga Klebsormidium nitens to perform an integrative transcriptomic and metabolomic analysis under high light in order to unveil key mechanisms involved in the early steps of plants terrestralization. We found a fast chloroplast retrograde signaling possibly mediated by reactive oxygen species and the inositol polyphosphate 1-phosphatase (SAL1) and 3'-phosphoadenosine-5'-phosphate (PAP) pathways inducing gene expression and accumulation of specific metabolites. Systems used by both Chlorophyta and Embryophyta were activated such as the xanthophyll cycle with an accumulation of zeaxanthin and protein folding and repair mechanisms constituted by NADPH-dependent thioredoxin reductases, thioredoxin-disulfide reductases, and peroxiredoxins. Similarly, cyclic electron flow, specifically the pathway dependent on proton gradient regulation 5, was strongly activated under high light. We detected a simultaneous co-activation of the non-photochemical quenching mechanisms based on LHC-like stress related (LHCSR) protein and the photosystem II subunit S that are specific to Chlorophyta and Embryophyta, respectively. Exclusive Embryophyta systems for the synthesis, sensing, and response to the phytohormone auxin were also activated under high light in K. nitens leading to an increase in auxin content with the concomitant accumulation of amino acids such as tryptophan, histidine, and phenylalanine.
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Affiliation(s)
- Emma Serrano-Pérez
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
- Department of Computer Science and Artificial Intelligence, Universidad de Sevilla, Seville, Spain
| | - Ana B. Romero-Losada
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
- Department of Computer Science and Artificial Intelligence, Universidad de Sevilla, Seville, Spain
| | - María Morales-Pineda
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - M. Elena García-Gómez
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Inmaculada Couso
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Mercedes García-González
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Francisco J. Romero-Campero
- Microalgae Systems Biology and Biotechnology Research Group, Institute for Plant Biochemistry and Photosynthesis, Universidad de Sevilla – Consejo Superior de Investigaciones Científicas, Seville, Spain
- Department of Computer Science and Artificial Intelligence, Universidad de Sevilla, Seville, Spain
- *Correspondence: Francisco J. Romero-Campero,
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28
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Kanazawa A, Chattopadhyay A, Kuhlgert S, Tuitupou H, Maiti T, Kramer DM. Light potentials of photosynthetic energy storage in the field: what limits the ability to use or dissipate rapidly increased light energy? ROYAL SOCIETY OPEN SCIENCE 2021; 8:211102. [PMID: 34925868 PMCID: PMC8672073 DOI: 10.1098/rsos.211102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
The responses of plant photosynthesis to rapid fluctuations in environmental conditions are critical for efficient conversion of light energy. These responses are not well-seen laboratory conditions and are difficult to probe in field environments. We demonstrate an open science approach to this problem that combines multifaceted measurements of photosynthesis and environmental conditions, and an unsupervised statistical clustering approach. In a selected set of data on mint (Mentha sp.), we show that 'light potentials' for linear electron flow and non-photochemical quenching (NPQ) upon rapid light increases are strongly suppressed in leaves previously exposed to low ambient photosynthetically active radiation (PAR) or low leaf temperatures, factors that can act both independently and cooperatively. Further analyses allowed us to test specific mechanisms. With decreasing leaf temperature or PAR, limitations to photosynthesis during high light fluctuations shifted from rapidly induced NPQ to photosynthetic control of electron flow at the cytochrome b6f complex. At low temperatures, high light induced lumen acidification, but did not induce NPQ, leading to accumulation of reduced electron transfer intermediates, probably inducing photodamage, revealing a potential target for improving the efficiency and robustness of photosynthesis. We discuss the implications of the approach for open science efforts to understand and improve crop productivity.
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Affiliation(s)
- Atsuko Kanazawa
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Abhijnan Chattopadhyay
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
- Department of Statistics and Probability, Michigan State University, East Lansing, MI 48824, USA
| | - Sebastian Kuhlgert
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
| | - Hainite Tuitupou
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
| | - Tapabrata Maiti
- Department of Statistics and Probability, Michigan State University, East Lansing, MI 48824, USA
| | - David M. Kramer
- MSU-DOE Plant Research Lab, Michigan State University, East Lansing, MI 48824, USA
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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29
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Wakao S, Niyogi KK. Chlamydomonas as a model for reactive oxygen species signaling and thiol redox regulation in the green lineage. PLANT PHYSIOLOGY 2021; 187:687-698. [PMID: 35237823 PMCID: PMC8491031 DOI: 10.1093/plphys/kiab355] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/13/2021] [Indexed: 05/15/2023]
Abstract
One-sentence summary: Advances in proteomic and transcriptomic studies have made Chlamydomonas a powerful research model in redox and reactive oxygen species regulation with unique and overlapping mechanisms with plants.
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Affiliation(s)
- Setsuko Wakao
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
- Author for communication: Senior author
| | - Krishna K. Niyogi
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA
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30
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Nikkanen L, Solymosi D, Jokel M, Allahverdiyeva Y. Regulatory electron transport pathways of photosynthesis in cyanobacteria and microalgae: Recent advances and biotechnological prospects. PHYSIOLOGIA PLANTARUM 2021; 173:514-525. [PMID: 33764547 DOI: 10.1111/ppl.13404] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Cyanobacteria and microalgae perform oxygenic photosynthesis where light energy is harnessed to split water into oxygen and protons. This process releases electrons that are used by the photosynthetic electron transport chain to form reducing equivalents that provide energy for the cell metabolism. Constant changes in environmental conditions, such as light availability, temperature, and access to nutrients, create the need to balance the photochemical reactions and the metabolic demands of the cell. Thus, cyanobacteria and microalgae evolved several auxiliary electron transport (AET) pathways to disperse the potentially harmful over-supply of absorbed energy. AET pathways are comprised of electron sinks, e.g. flavodiiron proteins (FDPs) or other terminal oxidases, and pathways that recycle electrons around photosystem I, like NADPH-dehydrogenase-like complexes (NDH) or the ferredoxin-plastoquinone reductase (FQR). Under controlled conditions the need for these AET pathways is decreased and AET can even be energetically wasteful. Therefore, redirecting photosynthetic reducing equivalents to biotechnologically useful reactions, catalyzed by i.e. innate hydrogenases or heterologous enzymes, offers novel possibilities to apply photosynthesis research.
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Affiliation(s)
- Lauri Nikkanen
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Daniel Solymosi
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Martina Jokel
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Life Technologies, University of Turku, Turku, Finland
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31
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Hupp J, McCoy JI, Millgan AJ, Peers G. Simultaneously measuring carbon uptake capacity and chlorophyll a fluorescence dynamics in algae. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria. Proc Natl Acad Sci U S A 2021; 118:2021523118. [PMID: 33836593 PMCID: PMC7980454 DOI: 10.1073/pnas.2021523118] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cyanobacteria have been increasingly explored as a biotechnological platform, although their economic feasibility relies in part on the capacity to maximize their photosynthetic, solar-to-biomass energy conversion efficiency. Here we show that cyanobacterial photosynthetic capacity can be increased by diverting cellular resources toward heterologous, energy-storing metabolic pathways and by reducing electron flow to photoprotective, but energy-dissipating, oxygen reduction reactions. We further show that these heterologous sinks can partially contribute to photosystem I (PSI) oxidation, suggesting an engineering strategy to improve both energy storage capacity and robustness by selective diversion of excess photosynthetic capacity to productive processes. Cyanobacteria must prevent imbalances between absorbed light energy (source) and the metabolic capacity (sink) to utilize it to protect their photosynthetic apparatus against damage. A number of photoprotective mechanisms assist in dissipating excess absorbed energy, including respiratory terminal oxidases and flavodiiron proteins, but inherently reduce photosynthetic efficiency. Recently, it has been hypothesized that some engineered metabolic pathways may improve photosynthetic performance by correcting source/sink imbalances. In the context of this subject, we explored the interconnectivity between endogenous electron valves, and the activation of one or more heterologous metabolic sinks. We coexpressed two heterologous metabolic pathways that have been previously shown to positively impact photosynthetic activity in cyanobacteria, a sucrose production pathway (consuming ATP and reductant) and a reductant-only consuming cytochrome P450. Sucrose export was associated with improved quantum yield of phtotosystem II (PSII) and enhanced electron transport chain flux, especially at lower illumination levels, while cytochrome P450 activity led to photosynthetic enhancements primarily observed under high light. Moreover, coexpression of these two heterologous sinks showed additive impacts on photosynthesis, indicating that neither sink alone was capable of utilizing the full “overcapacity” of the electron transport chain. We find that heterologous sinks may partially compensate for the loss of photosystem I (PSI) oxidizing mechanisms even under rapid illumination changes, although this compensation is incomplete. Our results provide support for the theory that heterologous metabolism can act as a photosynthetic sink and exhibit some overlapping functionality with photoprotective mechanisms, while potentially conserving energy within useful metabolic products that might otherwise be “lost.”
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Kuo EY, Lee TM. Molecular Mechanisms Underlying the Acclimation of Chlamydomonas reinhardtii Against Nitric Oxide Stress. FRONTIERS IN PLANT SCIENCE 2021; 12:690763. [PMID: 34421944 PMCID: PMC8374494 DOI: 10.3389/fpls.2021.690763] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
The acclimation mechanism of Chlamydomonas reinhardtii to nitric oxide (NO) was studied by exposure to S-nitroso-N-acetylpenicillamine (SNAP), a NO donor. Treatment with 0.1 or 0.3 mM SNAP transiently inhibited photosynthesis within 1 h, followed by a recovery, while 1.0 mM SNAP treatment caused irreversible photosynthesis inhibition and mortality. The SNAP effects are avoided in the presence of the NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide (cPTIO). RNA-seq, qPCR, and biochemical analyses were conducted to decode the metabolic shifts under NO stress by exposure to 0.3 mM SNAP in the presence or absence of 0.4 mM cPTIO. These findings revealed that the acclimation to NO stress comprises a temporally orchestrated implementation of metabolic processes: (1). modulation of NADPH oxidase (respiratory burst oxidase-like 2, RBOL2) and ROS signaling pathways for downstream mechanism regulation, (2). trigger of NO scavenging elements to reduce NO level; (3). prevention of photo-oxidative risk through photosynthesis inhibition and antioxidant defense system induction; (4). acclimation to nitrogen and sulfur shortage; (5). attenuation of transcriptional and translational activity together with degradation of damaged proteins through protein trafficking machinery (ubiquitin, SNARE, and autophagy) and molecular chaperone system for dynamic regulation of protein homeostasis. In addition, the expression of the gene encoding NADPH oxidase, RBOL2, showed a transient increase while that of RBOL1 was slightly decreased after NO challenge. It reflects that NADPH oxidase, a regulator in ROS-mediated signaling pathway, may be involved in the responses of Chlamydomonas to NO stress. In conclusion, our findings provide insight into the molecular events underlying acclimation mechanisms in Chlamydomonas to NO stress.
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Affiliation(s)
- Eva YuHua Kuo
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Tse-Min Lee
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan
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Milrad Y, Schweitzer S, Feldman Y, Yacoby I. Bi-directional electron transfer between H2 and NADPH mitigates light fluctuation responses in green algae. PLANT PHYSIOLOGY 2021; 186:168-179. [PMID: 33793951 PMCID: PMC8154092 DOI: 10.1093/plphys/kiab051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/21/2021] [Indexed: 05/05/2023]
Abstract
The metabolism of green algae has been the focus of much research over the last century. These photosynthetic organisms can thrive under various conditions and adapt quickly to changing environments by concomitant usage of several metabolic apparatuses. The main electron coordinator in their chloroplasts, nicotinamide adenine dinucleotide phosphate (NADPH), participates in many enzymatic activities and is also responsible for inter-organellar communication. Under anaerobic conditions, green algae also accumulate molecular hydrogen (H2), a promising alternative for fossil fuels. However, to scale-up its accumulation, a firm understanding of its integration in the photosynthetic apparatus is still required. While it is generally accepted that NADPH metabolism correlates to H2 accumulation, the mechanism of this collaboration is still vague and relies on indirect measurements. Here, we investigated this connection in Chlamydomonas reinhardtii using simultaneous measurements of both dissolved gases concentration, NADPH fluorescence and electrochromic shifts at 520-546 nm. Our results indicate that energy transfer between H2 and NADPH is bi-directional and crucial for the maintenance of redox balance under light fluctuations. At light onset, NADPH consumption initially eventuates in H2 evolution, which initiates the photosynthetic electron flow. Later on, as illumination continues the majority of NADPH is diverted to the Calvin-Benson-Bassham cycle. Dark onset triggers re-assimilation of H2, which produces NADPH and so, enables initiation of dark fermentative metabolism.
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Affiliation(s)
- Yuval Milrad
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Shira Schweitzer
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Yael Feldman
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
- Author for communication: (I.Y.)
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Coordination of Cyclic Electron Flow and Water-Water Cycle Facilitates Photoprotection under Fluctuating Light and Temperature Stress in the Epiphytic Orchid Dendrobium officinale. PLANTS 2021; 10:plants10030606. [PMID: 33806869 PMCID: PMC8004707 DOI: 10.3390/plants10030606] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/13/2021] [Accepted: 03/13/2021] [Indexed: 02/08/2023]
Abstract
Photosystem I (PSI) is the primary target of photoinhibition under fluctuating light (FL). Photosynthetic organisms employ alternative electron flows to protect PSI under FL. However, the understanding of the coordination of alternative electron flows under FL at temperature stresses is limited. To address this question, we measured the chlorophyll fluorescence, P700 redox state, and electrochromic shift signal in leaves of Dendrobium officinale exposed to FL at 42 °C, 25 °C, and 4 °C. Upon a sudden increase in illumination at 42 °C and 25 °C, the water-water cycle (WWC) consumed a significant fraction of the extra reducing power, and thus avoided an over-reduction of PSI. However, WWC was inactivated at 4 °C, leading to an over-reduction of PSI within the first seconds after light increased. Therefore, the role of WWC under FL is largely dependent on temperature conditions. After an abrupt increase in light intensity, cyclic electron flow (CEF) around PSI was stimulated at any temperature. Therefore, CEF and WWC showed different temperature responses under FL. Furthermore, the enhancement of CEF and WWC at 42 °C quickly generated a sufficient trans-thylakoid proton gradient (ΔpH). The inactivation of WWC at 4 °C was partially compensated for by an increased CEF activity. These findings indicate that CEF and WWC coordinate to protect PSI under FL at temperature stresses.
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Lu Y, Gan Q, Iwai M, Alboresi A, Burlacot A, Dautermann O, Takahashi H, Crisanto T, Peltier G, Morosinotto T, Melis A, Niyogi KK. Role of an ancient light-harvesting protein of PSI in light absorption and photoprotection. Nat Commun 2021; 12:679. [PMID: 33514722 PMCID: PMC7846763 DOI: 10.1038/s41467-021-20967-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/05/2021] [Indexed: 12/18/2022] Open
Abstract
Diverse algae of the red lineage possess chlorophyll a-binding proteins termed LHCR, comprising the PSI light-harvesting system, which represent an ancient antenna form that evolved in red algae and was acquired through secondary endosymbiosis. However, the function and regulation of LHCR complexes remain obscure. Here we describe isolation of a Nannochloropsis oceanica LHCR mutant, named hlr1, which exhibits a greater tolerance to high-light (HL) stress compared to the wild type. We show that increased tolerance to HL of the mutant can be attributed to alterations in PSI, making it less prone to ROS production, thereby limiting oxidative damage and favoring growth in HL. HLR1 deficiency attenuates PSI light-harvesting capacity and growth of the mutant under light-limiting conditions. We conclude that HLR1, a member of a conserved and broadly distributed clade of LHCR proteins, plays a pivotal role in a dynamic balancing act between photoprotection and efficient light harvesting for photosynthesis. LHCR proteins are ancient chlorophyll a-binding antennas that evolved in diverse algae of the red lineage. Here Lu et al. characterize a red lineage LHCR mutant and show reduced oxidative damage in high light but attenuated growth under low light, thus demonstrating how LHCR proteins impact the balance between photoprotection and light harvesting.
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Affiliation(s)
- Yandu Lu
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, Haikou, Hainan, China. .,Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.
| | - Qinhua Gan
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, Haikou, Hainan, China
| | - Masakazu Iwai
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Adrien Burlacot
- 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-lezDurance, France
| | - Oliver Dautermann
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Hiroko Takahashi
- Department of Biochemistry and Molecular Biology, Graduate school of Science and Engineering, Saitama University, Saitama, Japan
| | - Thien Crisanto
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Gilles Peltier
- 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-lezDurance, France
| | | | - Anastasios Melis
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Krishna K Niyogi
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA. .,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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Vicino P, Carrillo J, Gómez R, Shahinnia F, Tula S, Melzer M, Rutten T, Carrillo N, Hajirezaei MR, Lodeyro AF. Expression of Flavodiiron Proteins Flv2-Flv4 in Chloroplasts of Arabidopsis and Tobacco Plants Provides Multiple Stress Tolerance. Int J Mol Sci 2021; 22:1178. [PMID: 33503994 PMCID: PMC7865949 DOI: 10.3390/ijms22031178] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 12/14/2022] Open
Abstract
With the notable exception of angiosperms, all phototrophs contain different sets of flavodiiron proteins that help to relieve the excess of excitation energy on the photosynthetic electron transport chain during adverse environmental conditions, presumably by reducing oxygen directly to water. Among them, the Flv2-Flv4 dimer is only found in β-cyanobacteria and induced by high light, supporting a role in stress protection. The possibility of a similar protective function in plants was assayed by expressing Synechocystis Flv2-Flv4 in chloroplasts of tobacco and Arabidopsis. Flv-expressing plants exhibited increased tolerance toward high irradiation, salinity, oxidants, and drought. Stress tolerance was reflected by better growth, preservation of photosynthetic activity, and membrane integrity. Metabolic profiling under drought showed enhanced accumulation of soluble sugars and amino acids in transgenic Arabidopsis and a remarkable shift of sucrose into starch, in line with metabolic responses of drought-tolerant genotypes. Our results indicate that the Flv2-Flv4 complex retains its stress protection activities when expressed in chloroplasts of angiosperm species by acting as an additional electron sink. The flv2-flv4 genes constitute a novel biotechnological tool to generate plants with increased tolerance to agronomically relevant stress conditions that represent a significant productivity constraint.
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Affiliation(s)
- Paula Vicino
- Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario 2000, Argentina; (P.V.); (J.C.); (R.G.); (N.C.)
| | - Julieta Carrillo
- Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario 2000, Argentina; (P.V.); (J.C.); (R.G.); (N.C.)
| | - Rodrigo Gómez
- Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario 2000, Argentina; (P.V.); (J.C.); (R.G.); (N.C.)
| | - Fahimeh Shahinnia
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, Corrensstrasse, D-06466 Stadt Seeland, Germany; (F.S.); (S.T.); (M.M.); (T.R.)
| | - Suresh Tula
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, Corrensstrasse, D-06466 Stadt Seeland, Germany; (F.S.); (S.T.); (M.M.); (T.R.)
| | - Michael Melzer
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, Corrensstrasse, D-06466 Stadt Seeland, Germany; (F.S.); (S.T.); (M.M.); (T.R.)
| | - Twan Rutten
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, Corrensstrasse, D-06466 Stadt Seeland, Germany; (F.S.); (S.T.); (M.M.); (T.R.)
| | - Néstor Carrillo
- Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario 2000, Argentina; (P.V.); (J.C.); (R.G.); (N.C.)
| | - Mohammad-Reza Hajirezaei
- Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, Corrensstrasse, D-06466 Stadt Seeland, Germany; (F.S.); (S.T.); (M.M.); (T.R.)
| | - Anabella F. Lodeyro
- Instituto de Biología Molecular y Celular de Rosario (IBR-UNR/CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Rosario 2000, Argentina; (P.V.); (J.C.); (R.G.); (N.C.)
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Shimakawa G, Hanawa H, Wada S, Hanke GT, Matsuda Y, Miyake C. Physiological Roles of Flavodiiron Proteins and Photorespiration in the Liverwort Marchantia polymorpha. FRONTIERS IN PLANT SCIENCE 2021; 12:668805. [PMID: 34489990 PMCID: PMC8418088 DOI: 10.3389/fpls.2021.668805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/30/2021] [Indexed: 05/19/2023]
Abstract
Against the potential risk in oxygenic photosynthesis, that is, the generation of reactive oxygen species, photosynthetic electron transport needs to be regulated in response to environmental fluctuations. One of the most important regulations is keeping the reaction center chlorophyll (P700) of photosystem I in its oxidized form in excess light conditions. The oxidation of P700 is supported by dissipating excess electrons safely to O2, and we previously found that the molecular mechanism of the alternative electron sink is changed from flavodiiron proteins (FLV) to photorespiration in the evolutionary history from cyanobacteria to plants. However, the overall picture of the regulation of photosynthetic electron transport is still not clear in bryophytes, the evolutionary intermediates. Here, we investigated the physiological roles of FLV and photorespiration for P700 oxidation in the liverwort Marchantia polymorpha by using the mutants deficient in FLV (flv1) at different O2 partial pressures. The effective quantum yield of photosystem II significantly decreased at 2kPa O2 in flv1, indicating that photorespiration functions as the electron sink. Nevertheless, it was clear from the phenotype of flv1 that FLV was dominant for P700 oxidation in M. polymorpha. These data suggested that photorespiration has yet not replaced FLV in functioning for P700 oxidation in the basal land plant probably because of the lower contribution to lumen acidification, compared with FLV, as reflected in the results of electrochromic shift analysis.
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Affiliation(s)
- Ginga Shimakawa
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Research Center for Solar Energy Chemistry, Osaka University, Suita, Japan
- Department of Biosciences, School of Biological and Environmental Sciences, Kwansei-Gakuin University, Nishinomiya, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
| | - Hitomi Hanawa
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Shinya Wada
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
| | - Guy T. Hanke
- School of Biochemistry and Chemistry, Queen Mary University of London, London, United Kingdom
| | - Yusuke Matsuda
- Department of Biosciences, School of Biological and Environmental Sciences, Kwansei-Gakuin University, Nishinomiya, Japan
| | - Chikahiro Miyake
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Core Research for Environmental Science and Technology, Japan Science and Technology Agency, Chiyoda, Japan
- *Correspondence: Chikahiro Miyake,
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An epigenetic gene silencing pathway selectively acting on transgenic DNA in the green alga Chlamydomonas. Nat Commun 2020; 11:6269. [PMID: 33293544 PMCID: PMC7722844 DOI: 10.1038/s41467-020-19983-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/05/2020] [Indexed: 01/08/2023] Open
Abstract
Silencing of exogenous DNA can make transgene expression very inefficient. Genetic screens in the model alga Chlamydomonas have demonstrated that transgene silencing can be overcome by mutations in unknown gene(s), thus producing algal strains that stably express foreign genes to high levels. Here, we show that the silencing mechanism specifically acts on transgenic DNA. Once a permissive chromatin structure has assembled, transgene expression can persist even in the absence of mutations disrupting the silencing pathway. We have identified the gene conferring the silencing and show it to encode a sirtuin-type histone deacetylase. Loss of gene function does not appreciably affect endogenous gene expression. Our data suggest that transgenic DNA is recognized and then quickly inactivated by the assembly of a repressive chromatin structure composed of deacetylated histones. We propose that this mechanism may have evolved to provide protection from potentially harmful types of environmental DNA. Strong transgene suppression has been observed in Chlamydomonas reinhardtii, but the underlying mechanism is unknown. Here, the authors identify a sirtuin-type histone deacetylase that selectively acts on transgenic DNA to repress gene expression by assembling a repressive chromatin structure composed of deacetylated histones.
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Roach T. LHCSR3-Type NPQ Prevents Photoinhibition and Slowed Growth under Fluctuating Light in Chlamydomonas reinhardtii. PLANTS 2020; 9:plants9111604. [PMID: 33218177 PMCID: PMC7698959 DOI: 10.3390/plants9111604] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/05/2020] [Accepted: 11/16/2020] [Indexed: 01/14/2023]
Abstract
Natural light intensities can rise several orders of magnitude over subsecond time spans, posing a major challenge for photosynthesis. Fluctuating light tolerance in the green alga Chlamydomonas reinhardtii requires alternative electron pathways, but the role of nonphotochemical quenching (NPQ) is not known. Here, fluctuating light (10 min actinic light followed by 10 min darkness) led to significant increase in NPQ/qE-related proteins, LHCSR1 and LHCSR3, relative to constant light of the same subsaturating or saturating intensity. Elevated levels of LHCSR1/3 increased the ability of cells to safely dissipate excess light energy to heat (i.e., qE-type NPQ) during dark to light transition, as measured with chlorophyll fluorescence. The low qE phenotype of the npq4 mutant, which is unable to produce LHCSR3, was abolished under fluctuating light, showing that LHCSR1 alone enables very high levels of qE. Photosystem (PS) levels were also affected by light treatments; constant light led to lower PsbA levels and Fv/Fm values, while fluctuating light led to lower PsaA and maximum P700+ levels, indicating that constant and fluctuating light induced PSII and PSI photoinhibition, respectively. Under fluctuating light, npq4 suffered more PSI photoinhibition and significantly slower growth rates than parental wild type, whereas npq1 and npq2 mutants affected in xanthophyll carotenoid compositions had identical growth under fluctuating and constant light. Overall, LHCSR3 rather than total qE capacity or zeaxanthin is shown to be important in C. reinhardtii in tolerating fluctuating light, potentially via preventing PSI photoinhibition.
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Affiliation(s)
- Thomas Roach
- Department of Botany and Centre for Molecular Biosciences Innsbruck, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
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Storti M, Segalla A, Mellon M, Alboresi A, Morosinotto T. Regulation of electron transport is essential for photosystem I stability and plant growth. THE NEW PHYTOLOGIST 2020; 228:1316-1326. [PMID: 32367526 DOI: 10.1111/nph.16643] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/27/2020] [Indexed: 06/11/2023]
Abstract
Photosynthetic electron transport is regulated by cyclic and pseudocyclic electron flow (CEF and PCEF) to maintain the balance between light availability and metabolic demands. CEF transfers electrons from photosystem I to the plastoquinone pool with two mechanisms, dependent either on PGR5/PGRL1 or on the type I NADH dehydrogenase-like (NDH) complex. PCEF uses electrons from photosystem I to reduce oxygen and in many groups of photosynthetic organisms, but remarkably not in angiosperms, it is catalyzed by flavodiiron proteins (FLVs). In this study, Physcomitrella patens plants depleted in PGRL1, NDH and FLVs in different combinations were generated and characterized, showing that all these mechanisms are active in this moss. Surprisingly, in contrast to flowering plants, Physcomitrella patens can cope with the simultaneous inactivation of PGR5- and NDH-dependent CEF but, when FLVs are also depleted, plants show strong growth reduction and photosynthetic activity is drastically reduced. The results demonstrate that mechanisms for modulation of photosynthetic electron transport have large functional overlap but are together indispensable to protect photosystem I from damage and they are an essential component for photosynthesis in any light regime.
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Affiliation(s)
- Mattia Storti
- Department of Biology, University of Padova, Padova, 35121, Italy
| | - Anna Segalla
- Department of Biology, University of Padova, Padova, 35121, Italy
| | - Marco Mellon
- Department of Biology, University of Padova, Padova, 35121, Italy
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Storti M, Puggioni MP, Segalla A, Morosinotto T, Alboresi A. The chloroplast NADH dehydrogenase-like complex influences the photosynthetic activity of the moss Physcomitrella patens. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5538-5548. [PMID: 32497206 DOI: 10.1093/jxb/eraa274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
Alternative electron pathways contribute to regulation of photosynthetic light reactions to adjust to metabolic demands in dynamic environments. The chloroplast NADH dehydrogenase-like (NDH) complex mediates the cyclic electron transport pathway around PSI in different cyanobacteria, algae, and plant species, but it is not fully conserved in all photosynthetic organisms. In order to assess how the physiological role of this complex changed during plant evolution, we isolated Physcomitrella patens lines knocked out for the NDHM gene that encodes a subunit fundamental for the activity of the complex. ndhm knockout mosses indicated high PSI acceptor side limitation upon abrupt changes in illumination. In P. patens, pseudo-cyclic electron transport mediated by flavodiiron proteins (FLVs) was also shown to prevent PSI over-reduction in plants exposed to light fluctuations. flva ndhm double knockout mosses had altered photosynthetic performance and growth defects under fluctuating light compared with the wild type and single knockout mutants. The results showed that while the contribution of NDH to electron transport is minor compared with FLV, NDH still participates in modulating photosynthetic activity, and it is critical to avoid PSI photoinhibition, especially when FLVs are inactive. The functional overlap between NDH- and FLV-dependent electron transport supports PSI activity and prevents its photoinhibition under light variations.
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Affiliation(s)
- Mattia Storti
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
| | | | - Anna Segalla
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
| | - Tomas Morosinotto
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
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Burlacot A, Burlacot F, Li-Beisson Y, Peltier G. Membrane Inlet Mass Spectrometry: A Powerful Tool for Algal Research. FRONTIERS IN PLANT SCIENCE 2020; 11:1302. [PMID: 33013952 PMCID: PMC7500362 DOI: 10.3389/fpls.2020.01302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/11/2020] [Indexed: 05/15/2023]
Abstract
Since the first great oxygenation event, photosynthetic microorganisms have continuously shaped the Earth's atmosphere. Studying biological mechanisms involved in the interaction between microalgae and cyanobacteria with the Earth's atmosphere requires the monitoring of gas exchange. Membrane inlet mass spectrometry (MIMS) has been developed in the early 1960s to study gas exchange mechanisms of photosynthetic cells. It has since played an important role in investigating various cellular processes that involve gaseous compounds (O2, CO2, NO, or H2) and in characterizing enzymatic activities in vitro or in vivo. With the development of affordable mass spectrometers, MIMS is gaining wide popularity and is now used by an increasing number of laboratories. However, it still requires an important theory and practical considerations to be used. Here, we provide a practical guide describing the current technical basis of a MIMS setup and the general principles of data processing. We further review how MIMS can be used to study various aspects of algal research and discuss how MIMS will be useful in addressing future scientific challenges.
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Zhou L, Gao S, Wu S, Han D, Wang H, Gu W, Hu Q, Wang J, Wang G. PGRL1 overexpression in Phaeodactylum tricornutum inhibits growth and reduces apparent PSII activity. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1850-1857. [PMID: 32526813 DOI: 10.1111/tpj.14872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/22/2020] [Accepted: 06/01/2020] [Indexed: 05/11/2023]
Abstract
Proton gradient regulation 5-like photosynthetic phenotype 1 (PGRL1)-dependent cyclic electron transport around photosystem I (PSI) plays important roles in the response to different stresses, including high light. Although the function of PGRL1 in higher plants and green algae has been thoroughly investigated, little information is available on the molecular mechanism of PGRL1 in diatoms. We created PGRL1 overexpression and knockdown transformants of Phaeodactylum tricornutum, the diatom model species, and investigated the impact on growth and photosynthesis under constant and fluctuating light conditions. PGRL1 over-accumulation resulted in significant decreases in growth rate and apparent photosystem II (PSII) activity and led to an opposing change of apparent PSII activity when turning to high light, demonstrating a similar influence on photosynthesis as a PSII inhibitor. Our results suggested that PGRL1 overexpression can reduce the apparent efficiency of PSII and inhibit growth in P. tricornutum. These findings provide physiological evidence that the accumulation of PGRL1 mainly functions around PSII instead of PSI.
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Affiliation(s)
- Lu Zhou
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
- College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shan Gao
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Songcui Wu
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Danxiang Han
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China
| | - Hui Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Wenhui Gu
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Qiang Hu
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China
| | - Jing Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
- College of Marine Life Sciences, Ocean University of China (OUC), Qingdao, 266003, China
| | - Guangce Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China
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Nikkanen L, Santana Sánchez A, Ermakova M, Rögner M, Cournac L, Allahverdiyeva Y. Functional redundancy between flavodiiron proteins and NDH-1 in Synechocystis sp. PCC 6803. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1460-1476. [PMID: 32394539 DOI: 10.1111/tpj.14812] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 05/09/2023]
Abstract
In oxygenic photosynthetic organisms, excluding angiosperms, flavodiiron proteins (FDPs) catalyze light-dependent reduction of O2 to H2 O. This alleviates electron pressure on the photosynthetic apparatus and protects it from photodamage. In Synechocystis sp. PCC 6803, four FDP isoforms function as hetero-oligomers of Flv1 and Flv3 and/or Flv2 and Flv4. An alternative electron transport pathway mediated by the NAD(P)H dehydrogenase-like complex (NDH-1) also contributes to redox hemostasis and the photoprotection of photosynthesis. Four NDH-1 types have been characterized in cyanobacteria: NDH-11 and NDH-12 , which function in respiration; and NDH-13 and NDH-14 , which function in CO2 uptake. All four types are involved in cyclic electron transport. Along with single FDP mutants (∆flv1 and Δflv3) and the double NDH-1 mutants (∆d1d2, which is deficient in NDH-11,2 and ∆d3d4, which is deficient in NDH-13,4 ), we studied triple mutants lacking one of Flv1 or Flv3, and NDH-11,2 or NDH-13,4 . We show that the presence of either Flv1/3 or NDH-11,2 , but not NDH-13,4 , is indispensable for survival during changes in growth conditions from high CO2 /moderate light to low CO2 /high light. Our results show functional redundancy between FDPs and NDH-11,2 under the studied conditions. We suggest that ferredoxin probably functions as a primary electron donor to both Flv1/3 and NDH-11,2 , allowing their functions to be dynamically coordinated for efficient oxidation of photosystem I and for photoprotection under variable CO2 and light availability.
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Affiliation(s)
- Lauri Nikkanen
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Anita Santana Sánchez
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Maria Ermakova
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Matthias Rögner
- Plant Biochemistry, Faculty of Biology & Biotechnology, Ruhr-University Bochum, Bochum, Germany
| | - Laurent Cournac
- Eco&Sols, University of Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
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Ware MA, Hunstiger D, Cantrell M, Peers G. A Chlorophyte Alga Utilizes Alternative Electron Transport for Primary Photoprotection. PLANT PHYSIOLOGY 2020; 183:1735-1748. [PMID: 32457091 PMCID: PMC7401117 DOI: 10.1104/pp.20.00373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 04/28/2020] [Indexed: 05/28/2023]
Abstract
The green alga Desmodesmus armatus is an emerging biofuel platform that produces high amounts of lipids and biomass in mass culture. We observed D. armatus in light-limiting, excess-light, and sinusoidal-light environments to investigate its photoacclimation behaviors and the mechanisms by which it dissipates excess energy. Chlorophyll a/b ratios and the functional absorption cross section of PSII suggested a constitutively small light-harvesting antenna size relative to other green algae. In situ and ex situ measurements of photo-physiology revealed that nonphotochemical quenching is not a significant contributor to photoprotection; however, cells do not suffer substantial photoinhibition despite its near absence. We performed membrane inlet mass spectrometry analysis to show that D. armatus has a very high capacity for alternative electron transport (AET) measured as light-dependent oxygen consumption. Up to 90% of electrons generated at PSII can be dissipated by AET in a water-water cycle during growth in rapidly fluctuating light environments, like those found in industrial-scale photobioreactors. This work highlights the diversity of photoprotective mechanisms present in algal systems, indicating that nonphotochemical quenching is not necessarily required for effective photoprotection in some algae, and suggests that engineering AET may be an attractive target for increasing the biomass productivity of some strains.
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Affiliation(s)
- Maxwell A Ware
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Darcy Hunstiger
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Michael Cantrell
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523
| | - Graham Peers
- Department of Biology, Colorado State University, Fort Collins, Colorado 80523
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Chlamydomonas reinhardtii, an Algal Model in the Nitrogen Cycle. PLANTS 2020; 9:plants9070903. [PMID: 32708782 PMCID: PMC7412212 DOI: 10.3390/plants9070903] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/12/2020] [Accepted: 07/13/2020] [Indexed: 02/06/2023]
Abstract
Nitrogen (N) is an essential constituent of all living organisms and the main limiting macronutrient. Even when dinitrogen gas is the most abundant form of N, it can only be used by fixing bacteria but is inaccessible to most organisms, algae among them. Algae preferentially use ammonium (NH4+) and nitrate (NO3−) for growth, and the reactions for their conversion into amino acids (N assimilation) constitute an important part of the nitrogen cycle by primary producers. Recently, it was claimed that algae are also involved in denitrification, because of the production of nitric oxide (NO), a signal molecule, which is also a substrate of NO reductases to produce nitrous oxide (N2O), a potent greenhouse gas. This review is focused on the microalga Chlamydomonas reinhardtii as an algal model and its participation in different reactions of the N cycle. Emphasis will be paid to new actors, such as putative genes involved in NO and N2O production and their occurrence in other algae genomes. Furthermore, algae/bacteria mutualism will be considered in terms of expanding the N cycle to ammonification and N fixation, which are based on the exchange of carbon and nitrogen between the two organisms.
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Identification of the electron donor to flavodiiron proteins in Synechocystis sp. PCC 6803 by in vivo spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148256. [PMID: 32622739 DOI: 10.1016/j.bbabio.2020.148256] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/19/2020] [Accepted: 06/19/2020] [Indexed: 01/18/2023]
Abstract
Flavodiiron proteins (FDPs) of photosynthetic organisms play a photoprotective role by reducing oxygen to water and thus avoiding the accumulation of excess electrons on the photosystem I (PSI) acceptor side under stress conditions. In Synechocystis sp. PCC 6803 grown under high CO2, both FDPs Flv1 and Flv3 are indispensable for oxygen reduction. We performed a detailed in vivo kinetic study of wild-type (WT) and Δflv1/3 strains of Synechocystis using light-induced NADPH fluorescence and near-infrared absorption of iron-sulfur clusters from ferredoxin and the PSI acceptors (FAFB), collectively named FeS. These measurements were performed under conditions where the Calvin-Benson cycle is inactive or poorly activated. Under such conditions, the NADPH decay following a short illumination decays in parallel in both strains and exhibits a time lag which is correlated to the presence of reduced FeS. On the contrary, reduced FeS decays much faster in WT than in Δflv1/3 (13 vs 2 s-1). These data unambiguously show that reduced ferredoxin, or possibly reduced FAFB, is the direct electron donor to the Flv1/Flv3 heterodimer. Evidences for large reduction of (FAFB) and recombination reactions within PSI were also provided by near-infrared absorption. Mutants lacking either the NDH1-L complex, the homolog of complex I of respiration, or the Pgr5 protein show no difference with WT in the oxidation of reduced FeS following a short illumination. These observations question the participation of a significant cyclic electron flow in cyanobacteria during the first seconds of the induction phase of photosynthesis.
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Burlacot A, Li-Beisson Y, Peltier G. Membrane Inlet Mass Spectrometry at the Crossroads of Photosynthesis, Biofuel, and Climate Research. PLANT PHYSIOLOGY 2020; 183:451-454. [PMID: 32317361 PMCID: PMC7271806 DOI: 10.1104/pp.20.00368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 05/02/2023]
Abstract
Advances in algal biology have built on gas exchange measurements by MIMS in the fields of photosynthesis, biofuel production, and climate research.
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Affiliation(s)
- Adrien Burlacot
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, Saint Paul-Lez-Durance, France F-13108
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, Saint Paul-Lez-Durance, France F-13108
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, Saint Paul-Lez-Durance, France F-13108
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