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Hüner NPA, Ivanov AG, Szyszka-Mroz B, Savitch LV, Smith DR, Kata V. Photostasis and photosynthetic adaptation to polar life. PHOTOSYNTHESIS RESEARCH 2024; 161:51-64. [PMID: 38865029 DOI: 10.1007/s11120-024-01104-7] [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: 04/24/2024] [Accepted: 05/29/2024] [Indexed: 06/13/2024]
Abstract
Photostasis is the light-dependent maintenance of energy balance associated with cellular homeostasis in photoautotrophs. We review evidence that illustrates how photosynthetic adaptation in polar photoautrophs such as aquatic green algae, cyanobacteria, boreal conifers as well as terrestrial angiosperms exhibit an astonishing plasticity in structure and function of the photosynthetic apparatus. This plasticity contributes to the maintenance of photostasis, which is essential for the long-term survival in the seemingly inhospitable Antarctic and Arctic habitats. However, evidence indicates that polar photoautrophic species exhibit different functional solutions for the maintenance of photostasis. We suggest that this reflects, in part, the genetic diversity symbolized by inherent genetic redundancy characteristic of polar photoautotrophs which enhances their survival in a thermodynamically challenging environment.
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Affiliation(s)
- Norman P A Hüner
- Department of Biology, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada.
| | - Alexander G Ivanov
- Department of Biology, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, Sofia, 1113, Bulgaria
| | - Beth Szyszka-Mroz
- Department of Biology, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada
| | - Leonid V Savitch
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, ON, K1A OC6, Canada
| | - David R Smith
- Department of Biology, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada
| | - Victoria Kata
- Department of Biology, University of Western Ontario, 1151 Richmond St, London, ON, N6A 3K7, Canada
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2
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Kim SY, Rasmussen U, Rydberg S. Impact of the neurotoxin β-N-methylamino-L-alanine on the diatom Thalassiosira pseudonana using metabolomics. MARINE POLLUTION BULLETIN 2024; 202:116299. [PMID: 38581736 DOI: 10.1016/j.marpolbul.2024.116299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 03/14/2024] [Accepted: 03/24/2024] [Indexed: 04/08/2024]
Abstract
The neurotoxin β-N-methylamino-L-alanine (BMAA) has emerged as an environmental factor related to neurodegenerative diseases. BMAA is produced by various microorganisms including cyanobacteria and diatoms, in diverse ecosystems. In the diatom Phaeodactylum tricornutum, BMAA is known to inhibit growth. The present study investigated the impact of BMAA on the diatom Thalassiosira pseudonana by exposing it to different concentrations of exogenous BMAA. Metabolomics was predominantly employed to investigate the effect of BMAA on T. pseudonana, and MetaboAnalyst (https://www.metabo-analyst.ca/) was used to identify BMAA-associated metabolisms/pathways in T. pseudonana. Furthermore, to explore the unique response, specific metabolites were compared between treatments. When the growth was obstructed by BMAA, 17 metabolisms/pathways including nitrogen and glutathione (i.e. oxidative stress) metabolisms, were influenced in T. pseudonana. This study has further determined that 11 out of 17 metabolisms/pathways could be essentially affected by BMAA, leading to the inhibition of diatom growth.
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Affiliation(s)
- Sea-Yong Kim
- Department of Ocean Environmental Sciences, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Ulla Rasmussen
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE 10691 Stockholm, Sweden
| | - Sara Rydberg
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE 10691 Stockholm, Sweden.
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3
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Li Z, Zhang Y, Li W, Irwin AJ, Finkel ZV. Common environmental stress responses in a model marine diatom. THE NEW PHYTOLOGIST 2023; 240:272-284. [PMID: 37488721 DOI: 10.1111/nph.19147] [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: 12/22/2022] [Accepted: 06/30/2023] [Indexed: 07/26/2023]
Abstract
Marine planktonic diatoms are among the most important contributors to phytoplankton blooms and marine net primary production. Their ecological success has been attributed to their ability to rapidly respond to changing environmental conditions. Here, we report common molecular mechanisms used by the model marine diatom Thalassiosira pseudonana to respond to 10 diverse environmental stressors using RNA-Seq analysis. We identify a specific subset of 1076 genes that are differentially expressed in response to stressors that induce an imbalance between energy or resource supply and metabolic capacity, which we termed the diatom environmental stress response (d-ESR). The d-ESR is primarily composed of genes that maintain proteome homeostasis and primary metabolism. Photosynthesis is strongly regulated in response to environmental stressors but chloroplast-encoded genes were predominantly upregulated while the nuclear-encoded genes were mostly downregulated in response to low light and high temperature. In aggregate, these results provide insight into the molecular mechanisms used by diatoms to respond to a range of environmental perturbations and the unique role of the chloroplast in managing environmental stress in diatoms. This study facilitates our understanding of the molecular mechanisms underpinning the ecological success of diatoms in the ocean.
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Affiliation(s)
- Zhengke Li
- School of Biological and Pharmaceutical Sciences, Shannxi University of Science and Technology, Xi'an, Shannxi, 710021, China
- Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
| | - Yong Zhang
- Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
- College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, Fujian, 350007, China
| | - Wei Li
- College of Life and Environmental Sciences, Huangshan University, Huangshan, Anhui, 245041, China
| | - Andrew J Irwin
- Department of Mathematics & Statistics, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
| | - Zoe V Finkel
- Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
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Nieves-Morión M, Camargo S, Bardi S, Ruiz MT, Flores E, Foster RA. Heterologous expression of genes from a cyanobacterial endosymbiont highlights substrate exchanges with its diatom host. PNAS NEXUS 2023; 2:pgad194. [PMID: 37383020 PMCID: PMC10299089 DOI: 10.1093/pnasnexus/pgad194] [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: 02/09/2023] [Accepted: 06/02/2023] [Indexed: 06/30/2023]
Abstract
A few genera of diatoms are widespread and thrive in low-nutrient waters of the open ocean due to their close association with N2-fixing, filamentous heterocyst-forming cyanobacteria. In one of these symbioses, the symbiont, Richelia euintracellularis, has penetrated the cell envelope of the host, Hemiaulus hauckii, and lives inside the host cytoplasm. How the partners interact, including how the symbiont sustains high rates of N2 fixation, is unstudied. Since R. euintracellularis has evaded isolation, heterologous expression of genes in model laboratory organisms was performed to identify the function of proteins from the endosymbiont. Gene complementation of a cyanobacterial invertase mutant and expression of the protein in Escherichia coli showed that R. euintracellularis HH01 possesses a neutral invertase that splits sucrose producing glucose and fructose. Several solute-binding proteins (SBPs) of ABC transporters encoded in the genome of R. euintracellularis HH01 were expressed in E. coli, and their substrates were characterized. The selected SBPs directly linked the host as the source of several substrates, e.g. sugars (sucrose and galactose), amino acids (glutamate and phenylalanine), and a polyamine (spermidine), to support the cyanobacterial symbiont. Finally, transcripts of genes encoding the invertase and SBPs were consistently detected in wild populations of H. hauckii collected from multiple stations and depths in the western tropical North Atlantic. Our results support the idea that the diatom host provides the endosymbiotic cyanobacterium with organic carbon to fuel N2 fixation. This knowledge is key to understanding the physiology of the globally significant H. hauckii-R. euintracellularis symbiosis.
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Affiliation(s)
- Mercedes Nieves-Morión
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm SE-106 91, Sweden
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville E-41092, Spain
| | - Sergio Camargo
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville E-41092, Spain
| | - Sepehr Bardi
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm SE-106 91, Sweden
| | - María Teresa Ruiz
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville E-41092, Spain
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Rehder L, Rost B, Rokitta SD. Abrupt and acclimation responses to changing temperature elicit divergent physiological effects in the diatom Phaeodactylum tricornutum. THE NEW PHYTOLOGIST 2023. [PMID: 37247339 DOI: 10.1111/nph.18982] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/14/2023] [Indexed: 05/31/2023]
Abstract
Growth rates and other biomass traits of phytoplankton are strongly affected by temperature. We hypothesized that resulting phenotypes originate from deviating temperature sensitivities of underlying physiological processes. We used membrane-inlet mass spectrometry to assess photosynthetic and respiratory O2 and CO2 fluxes in response to abrupt temperature changes as well as after acclimation periods in the diatom Phaeodactylum tricornutum. Abrupt temperature changes caused immediate over- or undershoots in most physiological processes, that is, photosynthetic oxygen release ( PS O 2 $$ {\mathrm{PS}}_{{\mathrm{O}}_2} $$ ), photosynthetic carbon uptake ( PS CO 2 $$ {\mathrm{PS}}_{{\mathrm{CO}}_2} $$ ), and respiratory oxygen release ( R O 2 $$ {\mathrm{R}}_{{\mathrm{O}}_2} $$ ). Over acclimation timescales, cells were, however, able to re-adjust their physiology and revert to phenotypic 'sweet spots'. Respiratory CO2 release ( R CO 2 $$ {\mathrm{R}}_{{\mathrm{CO}}_2} $$ ) was generally inhibited under high temperature and stimulated under low-temperature settings, on abrupt as well as acclimation timescales. Such behavior may help mitochondria to stabilize plastidial ATP : NADPH ratios and thus maximize photosynthetic carbon assimilation.
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Affiliation(s)
- Linda Rehder
- Alfred-Wegener-Institute, Helmholtz-Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, 27570, Germany
- FB2 Biology/Chemistry, University of Bremen, Leobener Straße, Bremen, 28359, Germany
| | - Björn Rost
- Alfred-Wegener-Institute, Helmholtz-Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, 27570, Germany
- FB2 Biology/Chemistry, University of Bremen, Leobener Straße, Bremen, 28359, Germany
| | - Sebastian D Rokitta
- Alfred-Wegener-Institute, Helmholtz-Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, 27570, Germany
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Gene expression during the formation of resting spores induced by nitrogen starvation in the marine diatom Chaetoceros socialis. BMC Genomics 2023; 24:106. [PMID: 36899305 PMCID: PMC9999646 DOI: 10.1186/s12864-023-09175-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 02/09/2023] [Indexed: 03/12/2023] Open
Abstract
BACKGROUND Dormancy is widespread in both multicellular and unicellular organisms. Among diatoms, unicellular microalgae at the base of all aquatic food webs, several species produce dormant cells (spores or resting cells) that can withstand long periods of adverse environmental conditions. RESULTS We present the first gene expression study during the process of spore formation induced by nitrogen depletion in the marine planktonic diatom Chaetoceros socialis. In this condition, genes related to photosynthesis and nitrate assimilation, including high-affinity nitrate transporters (NTRs), were downregulated. While the former result is a common reaction among diatoms under nitrogen stress, the latter seems to be exclusive of the spore-former C. socialis. The upregulation of catabolic pathways, such as tricarboxylic acid cycle, glyoxylate cycle and fatty acid beta-oxidation, suggests that this diatom could use lipids as a source of energy during the process of spore formation. Furthermore, the upregulation of a lipoxygenase and several aldehyde dehydrogenases (ALDHs) advocates the presence of oxylipin-mediated signaling, while the upregulation of genes involved in dormancy-related pathways conserved in other organisms (e.g. serine/threonine-protein kinases TOR and its inhibitor GATOR) provides interesting avenues for future explorations. CONCLUSIONS Our results demonstrate that the transition from an active growth phase to a resting one is characterized by marked metabolic changes and provides evidence for the presence of signaling pathways related to intercellular communication.
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Liu S, Storti M, Finazzi G, Bowler C, Dorrell RG. A metabolic, phylogenomic and environmental atlas of diatom plastid transporters from the model species Phaeodactylum. FRONTIERS IN PLANT SCIENCE 2022; 13:950467. [PMID: 36212359 PMCID: PMC9546453 DOI: 10.3389/fpls.2022.950467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
Diatoms are an important group of algae, contributing nearly 40% of total marine photosynthetic activity. However, the specific molecular agents and transporters underpinning the metabolic efficiency of the diatom plastid remain to be revealed. We performed in silico analyses of 70 predicted plastid transporters identified by genome-wide searches of Phaeodactylum tricornutum. We considered similarity with Arabidopsis thaliana plastid transporters, transcriptional co-regulation with genes encoding core plastid metabolic pathways and with genes encoded in the mitochondrial genomes, inferred evolutionary histories using single-gene phylogeny, and environmental expression trends using Tara Oceans meta-transcriptomics and meta-genomes data. Our data reveal diatoms conserve some of the ion, nucleotide and sugar plastid transporters associated with plants, such as non-specific triose phosphate transporters implicated in the transport of phosphorylated sugars, NTP/NDP and cation exchange transporters. However, our data also highlight the presence of diatom-specific transporter functions, such as carbon and amino acid transporters implicated in intricate plastid-mitochondria crosstalk events. These confirm previous observations that substrate non-specific triose phosphate transporters (TPT) may exist as principal transporters of phosphorylated sugars into and out of the diatom plastid, alongside suggesting probable agents of NTP exchange. Carbon and amino acid transport may be related to intricate metabolic plastid-mitochondria crosstalk. We additionally provide evidence from environmental meta-transcriptomic/meta- genomic data that plastid transporters may underpin diatom sensitivity to ocean warming, and identify a diatom plastid transporter (J43171) whose expression may be positively correlated with temperature.
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Affiliation(s)
- Shun Liu
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Centre National De La Recherche Scientifique (CNRS), Institut National De La Santé Et De La Recherche Médicale (INSERM), Université Paris Sciences et Lettres (PSL), Paris, France
- CNRS Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, Paris, France
| | - Mattia Storti
- Univ. Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique Energies Alternatives (CEA), Institut National Recherche Agriculture Alimentation Environnement (INRAE), Interdisciplinary Research Institute of Grenoble (IRIG), Laboratoire de Physiologie Cellulaire et Végétale (LPCV), Grenoble, France
| | - Giovanni Finazzi
- Univ. Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique Energies Alternatives (CEA), Institut National Recherche Agriculture Alimentation Environnement (INRAE), Interdisciplinary Research Institute of Grenoble (IRIG), Laboratoire de Physiologie Cellulaire et Végétale (LPCV), Grenoble, France
| | - Chris Bowler
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Centre National De La Recherche Scientifique (CNRS), Institut National De La Santé Et De La Recherche Médicale (INSERM), Université Paris Sciences et Lettres (PSL), Paris, France
- CNRS Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, Paris, France
| | - Richard G. Dorrell
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Centre National De La Recherche Scientifique (CNRS), Institut National De La Santé Et De La Recherche Médicale (INSERM), Université Paris Sciences et Lettres (PSL), Paris, France
- CNRS Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, Paris, France
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8
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Yu G, Nakajima K, Gruber A, Rio Bartulos C, Schober AF, Lepetit B, Yohannes E, Matsuda Y, Kroth PG. Mitochondrial phosphoenolpyruvate carboxylase contributes to carbon fixation in the diatom Phaeodactylum tricornutum at low inorganic carbon concentrations. THE NEW PHYTOLOGIST 2022; 235:1379-1393. [PMID: 35596716 DOI: 10.1111/nph.18268] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
Photosynthetic carbon fixation is often limited by CO2 availability, which led to the evolution of CO2 concentrating mechanisms (CCMs). Some diatoms possess CCMs that employ biochemical fixation of bicarbonate, similar to C4 plants, but whether biochemical CCMs are commonly found in diatoms is a subject of debate. In the diatom Phaeodactylum tricornutum, phosphoenolpyruvate carboxylase (PEPC) is present in two isoforms, PEPC1 in the plastids and PEPC2 in the mitochondria. We used real-time quantitative polymerase chain reaction, Western blots, and enzymatic assays to examine PEPC expression and PEPC activity, under low and high concentrations of dissolved inorganic carbon (DIC). We generated and analyzed individual knockout cell lines of PEPC1 and PEPC2, as well as a PEPC1/2 double-knockout strain. While we could not detect an altered phenotype in the PEPC1 knockout strains at ambient, low or high DIC concentrations, PEPC2 and the double-knockout strains grown under ambient air or lower DIC availability conditions showed reduced growth and photosynthetic affinity for DIC while behaving similarly to wild-type (WT) cells at high DIC concentrations. These mutants furthermore exhibited significantly lower 13 C/12 C ratios compared to the WT. Our data imply that in P. tricornutum at least parts of the CCM rely on biochemical bicarbonate fixation catalyzed by the mitochondrial PEPC2.
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Affiliation(s)
- Guilan Yu
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
| | - Kensuke Nakajima
- Department of Bioscience, School of Biological and Environmental Sciences, 1 Gakuen Uegahara, Sanda, Hyogo, 669-1330, Japan
| | - Ansgar Gruber
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05, České Budějovice, Czech Republic
| | | | | | - Bernard Lepetit
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
| | | | - Yusuke Matsuda
- Department of Bioscience, School of Biological and Environmental Sciences, 1 Gakuen Uegahara, Sanda, Hyogo, 669-1330, Japan
| | - Peter G Kroth
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
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Seydoux C, Storti M, Giovagnetti V, Matuszyńska A, Guglielmino E, Zhao X, Giustini C, Pan Y, Blommaert L, Angulo J, Ruban AV, Hu H, Bailleul B, Courtois F, Allorent G, Finazzi G. Impaired photoprotection in Phaeodactylum tricornutum KEA3 mutants reveals the proton regulatory circuit of diatoms light acclimation. THE NEW PHYTOLOGIST 2022; 234:578-591. [PMID: 35092009 PMCID: PMC9306478 DOI: 10.1111/nph.18003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
Diatoms are successful phytoplankton clades able to acclimate to changing environmental conditions, including e.g. variable light intensity. Diatoms are outstanding at dissipating light energy exceeding the maximum photosynthetic electron transfer (PET) capacity via the nonphotochemical quenching (NPQ) process. While the molecular effectors of NPQ as well as the involvement of the proton motive force (PMF) in its regulation are known, the regulators of the PET/PMF relationship remain unidentified in diatoms. We generated mutants of the H+ /K+ antiporter KEA3 in the model diatom Phaeodactylum tricornutum. Loss of KEA3 activity affects the PET/PMF coupling and NPQ responses at the onset of illumination, during transients and in steady-state conditions. Thus, this antiporter is a main regulator of the PET/PMF coupling. Consistent with this conclusion, a parsimonious model including only two free components, KEA3 and the diadinoxanthin de-epoxidase, describes most of the feedback loops between PET and NPQ. This simple regulatory system allows for efficient responses to fast (minutes) or slow (e.g. diel) changes in light environment, thanks to the presence of a regulatory calcium ion (Ca2+ )-binding domain in KEA3 modulating its activity. This circuit is likely tuned by the NPQ-effector proteins, LHCXs, providing diatoms with the required flexibility to thrive in different ocean provinces.
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Affiliation(s)
- Claire Seydoux
- CNRSCEAINRAEIRIGLPCVUniversité Grenoble AlpesGrenoble38000France
| | - Mattia Storti
- CNRSCEAINRAEIRIGLPCVUniversité Grenoble AlpesGrenoble38000France
| | - Vasco Giovagnetti
- Departement of BiochemistryQueen Mary University of LondonMile End RoadLondonE14NSUK
| | - Anna Matuszyńska
- Computational Life ScienceDepartment of BiologyRWTH Aachen UniversityWorringer Weg 1Aachen52074Germany
| | | | - Xue Zhao
- CNRSCEAINRAEIRIGLPCVUniversité Grenoble AlpesGrenoble38000France
| | - Cécile Giustini
- CNRSCEAINRAEIRIGLPCVUniversité Grenoble AlpesGrenoble38000France
| | - Yufang Pan
- Key Laboratory of Algal BiologyInstitute of HydrobiologyChinese Academy of SciencesWuhan430072China
| | - Lander Blommaert
- Laboratory of Chloroplast Biology and Light Sensing in MicroalgaeInstitut de Biologie Physico ChimiqueCNRSSorbonne UniversitéParis75005France
| | - Jhoanell Angulo
- CNRSCEAINRAEIRIGLPCVUniversité Grenoble AlpesGrenoble38000France
| | - Alexander V. Ruban
- Departement of BiochemistryQueen Mary University of LondonMile End RoadLondonE14NSUK
| | - Hanhua Hu
- Key Laboratory of Algal BiologyInstitute of HydrobiologyChinese Academy of SciencesWuhan430072China
| | - Benjamin Bailleul
- Laboratory of Chloroplast Biology and Light Sensing in MicroalgaeInstitut de Biologie Physico ChimiqueCNRSSorbonne UniversitéParis75005France
| | | | | | - Giovanni Finazzi
- CNRSCEAINRAEIRIGLPCVUniversité Grenoble AlpesGrenoble38000France
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10
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Azuma T, Pánek T, Tice AK, Kayama M, Kobayashi M, Miyashita H, Suzaki T, Yabuki A, Brown MW, Kamikawa R. An enigmatic stramenopile sheds light on early evolution in Ochrophyta plastid organellogenesis. Mol Biol Evol 2022; 39:6555011. [PMID: 35348760 PMCID: PMC9004409 DOI: 10.1093/molbev/msac065] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ochrophyta is an algal group belonging to the Stramenopiles and comprises diverse lineages of algae which contribute significantly to the oceanic ecosystems as primary producers. However, early evolution of the plastid organelle in Ochrophyta is not fully understood. In this study, we provide a well-supported tree of the Stramenopiles inferred by the large-scale phylogenomic analysis that unveils the eukaryvorous (nonphotosynthetic) protist Actinophrys sol (Actinophryidae) is closely related to Ochrophyta. We used genomic and transcriptomic data generated from A. sol to detect molecular traits of its plastid and we found no evidence of plastid genome and plastid-mediated biosynthesis, consistent with previous ultrastructural studies that did not identify any plastids in Actinophryidae. Moreover, our phylogenetic analyses of particular biosynthetic pathways provide no evidence of a current and past plastid in A. sol. However, we found more than a dozen organellar aminoacyl-tRNA synthases (aaRSs) that are of algal origin. Close relationships between aaRS from A. sol and their ochrophyte homologs document gene transfer of algal genes that happened before the divergence of Actinophryidae and Ochrophyta lineages. We further showed experimentally that organellar aaRSs of A. sol are targeted exclusively to mitochondria, although organellar aaRSs in Ochrophyta are dually targeted to mitochondria and plastids. Together, our findings suggested that the last common ancestor of Actinophryidae and Ochrophyta had not yet completed the establishment of host–plastid partnership as seen in the current Ochrophyta species, but acquired at least certain nuclear-encoded genes for the plastid functions.
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Affiliation(s)
- Tomonori Azuma
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida nihonmatsu cho, Sakyo ku, Kyoto, Kyoto, Japan
| | - Tomáš Pánek
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic.,Department of Biological Sciences, Mississippi State University, Mississippi State, MS, USA
| | - Alexander K Tice
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, USA
| | - Motoki Kayama
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida nihonmatsu cho, Sakyo ku, Kyoto, Kyoto, Japan
| | | | - Hideaki Miyashita
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida nihonmatsu cho, Sakyo ku, Kyoto, Kyoto, Japan
| | | | - Akinori Yabuki
- Japan Agency for Marine-Earth Science and Technology, Japan
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, USA
| | - Ryoma Kamikawa
- Graduate School of Agriculture, Kyoto University, Kitashirakawa oiwake cho, Sakyo ku, Kyoto, Kyoto, Japan
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11
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Dhanker R, Kumar R, Tiwari A, Kumar V. Diatoms as a biotechnological resource for the sustainable biofuel production: a state-of-the-art review. Biotechnol Genet Eng Rev 2022; 38:111-131. [PMID: 35343391 DOI: 10.1080/02648725.2022.2053319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The greenhouse gas emission from fossil fuel and higher economic cost in its transportation are stimulating scientists to explore biomass energy production at the local level. In the present review, the authors have explored the prospects of commercial-scale biofuels production from the microalgal group, diatoms. Insights on suitability of mass cultivation systems for large-scale production of diatoms have been deliberated based on published literature. Diatoms can proliferate extracting nutrients from the wastewater and the same biomass can be harvested for biofuel production. Residues can be further utilized for the formation of other bioproducts and biofertilizers. The residual applications of diatoms from mass culture are estimated to compensate for the additional costs incurred in the removal of impurities. Well-planned research is required to optimize the commercial-scale production of biofuels from diatoms. The aim of this review is therefore, to demonstrate the economically feasible, hygienically safe cultivation of diatoms on nutrients from wastewater, limitations in using diatoms for biofuel production, and how these limitations can be shorted out for optimum utilization of diatom for biofuel production.
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Affiliation(s)
- Raunak Dhanker
- Department of Basic and Applied Sciences, School of Engineering and Sciences, GD Goenka University, Gurugram, Haryana, India
| | - Ram Kumar
- Ecosystem Research Laboratory, Department of Environmental Science, School of Earth, Biological and Environmental Sciences, Central University of South Bihar, Fatehpur, Gaya, Bihar, India
| | - Archana Tiwari
- Diatom Research Laboratory, Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India
| | - Vineet Kumar
- Division, CSIR-National Environmental Engineering Research Institute (CSIR-NEERI)Waste Re-processing, Nehru Marg, Nagpur, Maharashtra, India
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12
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Hippmann AA, Schuback N, Moon K, McCrow JP, Allen AE, Foster LF, Green BR, Maldonado MT. Proteomic analysis of metabolic pathways supports chloroplast-mitochondria cross-talk in a Cu-limited diatom. PLANT DIRECT 2022; 6:e376. [PMID: 35079683 PMCID: PMC8777261 DOI: 10.1002/pld3.376] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 12/09/2021] [Accepted: 12/11/2021] [Indexed: 05/19/2023]
Abstract
Diatoms are one of the most successful phytoplankton groups in our oceans, being responsible for over 20% of the Earth's photosynthetic productivity. Their chimeric genomes have genes derived from red algae, green algae, bacteria, and heterotrophs, resulting in multiple isoenzymes targeted to different cellular compartments with the potential for differential regulation under nutrient limitation. The resulting interactions between metabolic pathways are not yet fully understood. We previously showed how acclimation to Cu limitation enhanced susceptibility to overreduction of the photosynthetic electron transport chain and its reorganization to favor photoprotection over light harvesting in the oceanic diatom Thalassiosira oceanica (Hippmann et al., 2017, 10.1371/journal.pone.0181753). In order to gain a better understanding of the overall metabolic changes that help alleviate the stress of Cu limitation, we have further analyzed the comprehensive proteomic datasets generated in that study to identify differentially expressed proteins involved in carbon, nitrogen, and oxidative stress-related metabolic pathways. Metabolic pathway analysis showed integrated responses to Cu limitation. The upregulation of ferredoxin (Fdx) was correlated with upregulation of plastidial Fdx-dependent isoenzymes involved in nitrogen assimilation as well as enzymes involved in glutathione synthesis, thus suggesting an integration of nitrogen uptake and metabolism with photosynthesis and oxidative stress resistance. The differential expression of glycolytic isoenzymes located in the chloroplast and mitochondria may enable them to channel both excess electrons and/or ATP between these compartments. An additional support for chloroplast-mitochondrial cross-talk is the increased expression of chloroplast and mitochondrial proteins involved in the proposed malate shunt under Cu limitation.
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Affiliation(s)
- Anna A. Hippmann
- Department of Earth Ocean and Atmospheric ScienceUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Nina Schuback
- Department of Earth Ocean and Atmospheric ScienceUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Kyung‐Mee Moon
- Biochemistry and Molecular BiologyMichael Smith LaboratoriesVancouverBritish ColumbiaCanada
| | - John P. McCrow
- Microbial and Environmental GenomicsJ. Craig Venter InstituteLa JollaCAUSA
| | - Andrew E. Allen
- Microbial and Environmental GenomicsJ. Craig Venter InstituteLa JollaCAUSA
- Scripps Institution of OceanographyUniversity of CaliforniaSan DiegoCAUSA
| | - Leonard F. Foster
- Biochemistry and Molecular BiologyMichael Smith LaboratoriesVancouverBritish ColumbiaCanada
| | - Beverley R. Green
- Department of BotanyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Maria T. Maldonado
- Department of Earth Ocean and Atmospheric ScienceUniversity of British ColumbiaVancouverBritish ColumbiaCanada
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13
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Gain G, Vega de Luna F, Cordoba J, Perez E, Degand H, Morsomme P, Thiry M, Baurain D, Pierangelini M, Cardol P. Trophic state alters the mechanism whereby energetic coupling between photosynthesis and respiration occurs in Euglena gracilis. THE NEW PHYTOLOGIST 2021; 232:1603-1617. [PMID: 34392544 PMCID: PMC9292222 DOI: 10.1111/nph.17677] [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] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
The coupling between mitochondrial respiration and photosynthesis plays an important role in the energetic physiology of green plants and some secondary-red photosynthetic eukaryotes (diatoms), allowing an efficient CO2 assimilation and optimal growth. Using the flagellate Euglena gracilis, we first tested if photosynthesis-respiration coupling occurs in this species harbouring secondary green plastids (i.e. originated from an endosymbiosis between a green alga and a phagotrophic euglenozoan). Second, we tested how the trophic state (mixotrophy and photoautotrophy) of the cell alters the mechanisms involved in the photosynthesis-respiration coupling. Energetic coupling between photosynthesis and respiration was determined by testing the effect of respiratory inhibitors on photosynthesis, and measuring the simultaneous variation of photosynthesis and respiration rates as a function of temperature (i.e. thermal response curves). The mechanism involved in the photosynthesis-respiration coupling was assessed by combining proteomics, biophysical and cytological analyses. Our work shows that there is photosynthesis-respiration coupling and membrane contacts between mitochondria and chloroplasts in E. gracilis. However, whereas in mixotrophy adjustment of the chloroplast ATP/NADPH ratio drives the interaction, in photoautotrophy the coupling is conditioned by CO2 limitation and photorespiration. This indicates that maintenance of photosynthesis-respiration coupling, through plastic metabolic responses, is key to E. gracilis functioning under changing environmental conditions.
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Affiliation(s)
- Gwenaëlle Gain
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Félix Vega de Luna
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Javier Cordoba
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Emilie Perez
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Hervé Degand
- Louvain Institute of Biomolecular Science and Technology (LIBST)UCLouvainLouvain‐la‐NeuveB‐1348Belgium
| | - Pierre Morsomme
- Louvain Institute of Biomolecular Science and Technology (LIBST)UCLouvainLouvain‐la‐NeuveB‐1348Belgium
| | - Marc Thiry
- Laboratoire de Biologie Cellulaire et TissulaireGiga‐NeurosciencesULiègeLiègeB‐4000Belgium
| | - Denis Baurain
- InBioS – PhytoSYSTEMSEukaryotic PhylogenomicsULiègeLiègeB‐4000Belgium
| | - Mattia Pierangelini
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Pierre Cardol
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
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14
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Liu M, Zhao Y, Sun Y, Wu P, Zhou S, Ren L. Diatom DNA barcodes for forensic discrimination of drowning incidents. FEMS Microbiol Lett 2021; 367:5896452. [PMID: 32832990 DOI: 10.1093/femsle/fnaa145] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/20/2020] [Indexed: 12/12/2022] Open
Abstract
The presence of diatoms in victim's internal organs has been regarded as a gold biological evidence of drowning. The idea becomes true at the advent of DNA metabarcoding. Unfortunately, the DNA barcode of diatoms are far from being applicable due to neither consensus on the barcode and nor reliable reference library.In this study we tested 23 pairs of primers, including two new primer pairs, Baci18S (V4 of 18S) and BacirbcL (central region of rbcL), for amplifying fragments of 16S/18S, 23S/28S, COI, ITS and rbcL. A total of five pairs of primers performed satisfactory for diatoms. We used three of them, 18S605 (V2 + V3 of 18S), Baci18S and BacirbcL, to barcode four water samples using next generation sequencing platform. The results showed that these primers worked well for NGS metabarcoding of diatoms. We suggest that 18S605, Baci18S and BacirbcL be barcodes of diatoms and the corresponding primer pairs be used. Considering a quite high proportion of sequences deposited in GenBank were mislabeled, the most urgent task for DNA barcoding of diatoms is to create standard sequences using correctly identified specimens, ideally type specimens.
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Affiliation(s)
- Mengyan Liu
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13, HangkongRoad, Wuhan 430030, Hubei, P.R. China.,Forensic Judicial Appraisal Center of Beijing Public Security Bureau, No.1, Longgang Beijing Road, Beijing 100192, P.R. China
| | - Yi Zhao
- Forensic Judicial Appraisal Center of Beijing Public Security Bureau, No.1, Longgang Beijing Road, Beijing 100192, P.R. China
| | - Yuzhe Sun
- State Key Laboratory of Systematic & Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Xiangshan street, Beijing 100093, P.R. China.,College of Life Sciences, University of Chinese Academy of Sciences, Yuquan road, Beijing 100049, P.R. China
| | - Ping Wu
- State Key Laboratory of Systematic & Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Xiangshan street, Beijing 100093, P.R. China.,College of Life Sciences, University of Chinese Academy of Sciences, Yuquan road, Beijing 100049, P.R. China
| | - Shiliang Zhou
- State Key Laboratory of Systematic & Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Xiangshan street, Beijing 100093, P.R. China.,College of Life Sciences, University of Chinese Academy of Sciences, Yuquan road, Beijing 100049, P.R. China
| | - Liang Ren
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13, HangkongRoad, Wuhan 430030, Hubei, P.R. China
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15
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Phylogenomic fingerprinting of tempo and functions of horizontal gene transfer within ochrophytes. Proc Natl Acad Sci U S A 2021; 118:2009974118. [PMID: 33419955 DOI: 10.1073/pnas.2009974118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Horizontal gene transfer (HGT) is an important source of novelty in eukaryotic genomes. This is particularly true for the ochrophytes, a diverse and important group of algae. Previous studies have shown that ochrophytes possess a mosaic of genes derived from bacteria and eukaryotic algae, acquired through chloroplast endosymbiosis and from HGTs, although understanding of the time points and mechanisms underpinning these transfers has been restricted by the depth of taxonomic sampling possible. We harness an expanded set of ochrophyte sequence libraries, alongside automated and manual phylogenetic annotation, in silico modeling, and experimental techniques, to assess the frequency and functions of HGT across this lineage. Through manual annotation of thousands of single-gene trees, we identify continuous bacterial HGT as the predominant source of recently arrived genes in the model diatom Phaeodactylum tricornutum Using a large-scale automated dataset, a multigene ochrophyte reference tree, and mathematical reconciliation of gene trees, we note a probable elevation of bacterial HGTs at foundational points in diatom evolution, following their divergence from other ochrophytes. Finally, we demonstrate that throughout ochrophyte evolutionary history, bacterial HGTs have been enriched in genes encoding secreted proteins. Our study provides insights into the sources and frequency of HGTs, and functional contributions that HGT has made to algal evolution.
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16
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Smith R, Jouhet J, Gandini C, Nekrasov V, Marechal E, Napier JA, Sayanova O. Plastidial acyl carrier protein Δ9-desaturase modulates eicosapentaenoic acid biosynthesis and triacylglycerol accumulation in Phaeodactylum tricornutum. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1247-1259. [PMID: 33725374 PMCID: PMC8360179 DOI: 10.1111/tpj.15231] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 02/26/2021] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
The unicellular marine diatom Phaeodactylum tricornutum accumulates up to 35% eicosapentaenoic acid (EPA, 20:5n3) and has been used as a model organism to study long chain polyunsaturated fatty acids (LC-PUFA) biosynthesis due to an excellent annotated genome sequence and established transformation system. In P. tricornutum, the majority of EPA accumulates in polar lipids, particularly in galactolipids such as mono- and di-galactosyldiacylglycerol. LC-PUFA biosynthesis is considered to start from oleic acid (18:1n9). EPA can be synthesized via a series of desaturation and elongation steps occurring at the endoplasmic reticulum and newly synthesized EPA is then imported into the plastids for incorporation into galactolipids via an unknown route. The basis for the flux of EPA is fundamental to understanding LC-PUFA biosynthesis in diatoms. We used P. tricornutum to study acyl modifying activities, upstream of 18:1n9, on subsequent LC-PUFA biosynthesis. We identified the gene coding for the plastidial acyl carrier protein Δ9-desaturase, a key enzyme in fatty acid modification and analyzed the impact of overexpression and knock out of this gene on glycerolipid metabolism. This revealed a previously unknown role of this soluble desaturase in EPA synthesis and production of triacylglycerol. This study provides further insight into the distinctive nature of lipid metabolism in the marine diatom P. tricornutum and suggests additional approaches for tailoring oil composition in microalgae.
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Affiliation(s)
- Richard Smith
- Department of Plant SciencesRothamsted ResearchHarpendenHertsAL5 2JQUK
- Present address:
AlgenuityEden LaboratoryBroadmead RoadStewartbyMK43 9NDUK
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale Univ. Grenoble AlpesCNRSIRAECEAIRIGGrenoble38000France
| | - Chiara Gandini
- Department of Plant SciencesRothamsted ResearchHarpendenHertsAL5 2JQUK
- Present address:
Open Bioeconomy LaboratoryDepartment of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Vladimir Nekrasov
- Department of Plant SciencesRothamsted ResearchHarpendenHertsAL5 2JQUK
| | - Eric Marechal
- Laboratoire de Physiologie Cellulaire et Végétale Univ. Grenoble AlpesCNRSIRAECEAIRIGGrenoble38000France
| | | | - Olga Sayanova
- Department of Plant SciencesRothamsted ResearchHarpendenHertsAL5 2JQUK
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17
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Behrenfeld MJ, Halsey KH, Boss E, Karp‐Boss L, Milligan AJ, Peers G. Thoughts on the evolution and ecological niche of diatoms. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1457] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Michael J. Behrenfeld
- Department of Botany and Plant Pathology Oregon State University 4575 SW Research Way Corvallis Oregon 97333 USA
| | - Kimberly H. Halsey
- Department of Microbiology Oregon State University Nash Hall 226 Corvallis Oregon 97331 USA
| | - Emmanuel Boss
- School of Marine Sciences University of Maine 5706 Aubert Hall Orono Maine 04469‐5706 USA
| | - Lee Karp‐Boss
- School of Marine Sciences University of Maine 5706 Aubert Hall Orono Maine 04469‐5706 USA
| | - Allen J. Milligan
- Department of Botany and Plant Pathology Oregon State University 4575 SW Research Way Corvallis Oregon 97333 USA
| | - Graham Peers
- Department of Biology Colorado State University Biology Building, Room 111, 1878 Campus Delivery Fort Collins Colorado 80523‐1878 USA
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18
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Galas L, Burel C, Schapman D, Ropitaux M, Bernard S, Bénard M, Bardor M. Comparative Structural and Functional Analyses of the Fusiform, Oval, and Triradiate Morphotypes of Phaeodactylum tricornutum Pt3 Strain. FRONTIERS IN PLANT SCIENCE 2021; 12:638181. [PMID: 33912207 PMCID: PMC8072121 DOI: 10.3389/fpls.2021.638181] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 03/16/2021] [Indexed: 05/24/2023]
Abstract
The diatom Phaeodactylum tricornutum is a marine unicellular microalga that exists under three main morphotypes: oval, fusiform, and triradiate. Previous works have demonstrated that the oval morphotype of P. tricornutum Pt3 strain presents specific metabolic features. Here, we compared the cellular organization of the main morphotypes of the diatom P. tricornutum Pt3 strain through transmission electron and advanced light microscopies. The three morphotypes share similarities including spectral characteristics of the plastid, the location of the nucleus, the organization of mitochondria around the plastid as well as the existence of both a F-actin cortex, and an intracellular network of F-actin. In contrast, compared to fusiform and triradiate cells, oval cells spontaneously release proteins more rapidly. In addition, comparison of whole transcriptomes of oval versus fusiform or triradiate cells revealed numerous differential expression of positive and negative regulators belonging to the complex dynamic secretory machinery. This study highlights the specificities occurring within the oval morphotype underlying that the oval cells secrete proteins more rapidly.
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Affiliation(s)
- Ludovic Galas
- Normandie University, UNIROUEN, INSERM, PRIMACEN, Rouen, France
| | - Carole Burel
- Normandie University, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (Glyco-MEV) EA4358, Rouen, France
| | - Damien Schapman
- Normandie University, UNIROUEN, INSERM, PRIMACEN, Rouen, France
| | - Marc Ropitaux
- Normandie University, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (Glyco-MEV) EA4358, Rouen, France
| | - Sophie Bernard
- Normandie University, UNIROUEN, INSERM, PRIMACEN, Rouen, France
- Normandie University, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (Glyco-MEV) EA4358, Rouen, France
| | - Magalie Bénard
- Normandie University, UNIROUEN, INSERM, PRIMACEN, Rouen, France
| | - Muriel Bardor
- Normandie University, UNIROUEN, Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (Glyco-MEV) EA4358, Rouen, France
- Institut Universitaire de France, Paris, France
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19
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ROS Homeostasis and Plant Salt Tolerance: Plant Nanobiotechnology Updates. SUSTAINABILITY 2021. [DOI: 10.3390/su13063552] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Salinity is an issue impairing crop production across the globe. Under salinity stress, besides the osmotic stress and Na+ toxicity, ROS (reactive oxygen species) overaccumulation is a secondary stress which further impairs plant performance. Chloroplasts, mitochondria, the apoplast, and peroxisomes are the main ROS generation sites in salt-stressed plants. In this review, we summarize ROS generation, enzymatic and non-enzymatic antioxidant systems in salt-stressed plants, and the potential for plant biotechnology to maintain ROS homeostasis. Overall, this review summarizes the current understanding of ROS homeostasis of salt-stressed plants and highlights potential applications of plant nanobiotechnology to enhance plant tolerance to stresses.
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20
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Kayanja GE, Ibrahim IM, Puthiyaveetil S. Regulation of Phaeodactylum plastid gene transcription by redox, light, and circadian signals. PHOTOSYNTHESIS RESEARCH 2021; 147:317-328. [PMID: 33387192 DOI: 10.1007/s11120-020-00811-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
Diatoms are a diverse group of photosynthetic unicellular algae with a plastid of red-algal origin. As prolific primary producers in the ocean, diatoms fix as much carbon as all rainforests combined. The molecular mechanisms that contribute to the high photosynthetic productivity and ecological success of diatoms are however not yet fully understood. Using the model diatom Phaeodactylum tricornutum, here we show rhythmic transcript accumulation of plastid psaA, psbA, petB, and atpB genes as driven by a free running circadian clock. Treatment with the electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea overrides the circadian signal by markedly downregulating transcription of psaA, petB, and atpB genes but not the psbA gene. Changes in light quantity produce little change in plastid gene transcription while the effect of light quality seems modest with only the psaA gene responding in a pattern that is dependent on the redox state of the plastoquinone pool. The significance of these plastid transcriptional responses and the identity of the underlying genetic control systems are discussed with relevance to diatom photosynthetic acclimation.
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Affiliation(s)
- Gilbert E Kayanja
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Iskander M Ibrahim
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Sujith Puthiyaveetil
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA.
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21
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Cainzos M, Marchetti F, Popovich C, Leonardi P, Pagnussat G, Zabaleta E. Gamma carbonic anhydrases are subunits of the mitochondrial complex I of diatoms. Mol Microbiol 2021; 116:109-125. [PMID: 33550595 DOI: 10.1111/mmi.14694] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 01/12/2021] [Accepted: 02/04/2021] [Indexed: 12/21/2022]
Abstract
Diatoms are unicellular organisms containing red algal-derived plastids that probably originated as result of serial endosymbioses between an ancestral heterotrophic organism and a red alga or cryptophyta algae from which has only the chloroplast left. Diatom mitochondria are thus believed to derive from the exosymbiont. Unlike animals and fungi, diatoms seem to contain ancestral respiratory chains. In support of this, genes encoding gamma type carbonic anhydrases (CAs) whose products were shown to be intrinsic complex I subunits in plants, Euglena and Acanthamoeba were found in diatoms, a representative of Stramenopiles. In this work, we experimentally show that mitochondrial complex I in diatoms is a large complex containing gamma type CA subunits, supporting an ancestral origin. By using a bioinformatic approach, a complex I integrated CA domain with heterotrimeric subunit composition is proposed.
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Affiliation(s)
- Maximiliano Cainzos
- IIB-CONICET-Universidad Nacional de Mar del Plata, Instituto de Investigaciones Biológicas, Mar del Plata, Argentina
| | - Fernanda Marchetti
- IIB-CONICET-Universidad Nacional de Mar del Plata, Instituto de Investigaciones Biológicas, Mar del Plata, Argentina
| | - Cecilia Popovich
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS) CONICET-UNS, Bahía Blanca, Argentina.,Centro de Emprendedorismo y Desarrollo Territorial Sostenible (CEDETS) CIC-UPSO, Bahía Blanca, Argentina
| | - Patricia Leonardi
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS) CONICET-UNS, Bahía Blanca, Argentina
| | - Gabriela Pagnussat
- IIB-CONICET-Universidad Nacional de Mar del Plata, Instituto de Investigaciones Biológicas, Mar del Plata, Argentina
| | - Eduardo Zabaleta
- IIB-CONICET-Universidad Nacional de Mar del Plata, Instituto de Investigaciones Biológicas, Mar del Plata, Argentina
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22
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Turnšek J, Brunson JK, Viedma MDPM, Deerinck TJ, Horák A, Oborník M, Bielinski VA, Allen AE. Proximity proteomics in a marine diatom reveals a putative cell surface-to-chloroplast iron trafficking pathway. eLife 2021; 10:e52770. [PMID: 33591270 PMCID: PMC7972479 DOI: 10.7554/elife.52770] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/15/2021] [Indexed: 12/16/2022] Open
Abstract
Iron is a biochemically critical metal cofactor in enzymes involved in photosynthesis, cellular respiration, nitrate assimilation, nitrogen fixation, and reactive oxygen species defense. Marine microeukaryotes have evolved a phytotransferrin-based iron uptake system to cope with iron scarcity, a major factor limiting primary productivity in the global ocean. Diatom phytotransferrin is endocytosed; however, proteins downstream of this environmentally ubiquitous iron receptor are unknown. We applied engineered ascorbate peroxidase APEX2-based subcellular proteomics to catalog proximal proteins of phytotransferrin in the model marine diatom Phaeodactylum tricornutum. Proteins encoded by poorly characterized iron-sensitive genes were identified including three that are expressed from a chromosomal gene cluster. Two of them showed unambiguous colocalization with phytotransferrin adjacent to the chloroplast. Further phylogenetic, domain, and biochemical analyses suggest their involvement in intracellular iron processing. Proximity proteomics holds enormous potential to glean new insights into iron acquisition pathways and beyond in these evolutionarily, ecologically, and biotechnologically important microalgae.
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Affiliation(s)
- Jernej Turnšek
- Biological and Biomedical Sciences, The Graduate School of Arts and Sciences, Harvard UniversityCambridgeUnited States
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
- Wyss Institute for Biologically Inspired Engineering, Harvard UniversityBostonUnited States
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San DiegoLa JollaUnited States
- Center for Research in Biological Systems, University of California San DiegoLa JollaUnited States
- Microbial and Environmental Genomics, J. Craig Venter InstituteLa JollaUnited States
| | - John K Brunson
- Microbial and Environmental Genomics, J. Craig Venter InstituteLa JollaUnited States
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San DiegoLa JollaUnited States
| | | | - Thomas J Deerinck
- National Center for Microscopy and Imaging Research, University of California San DiegoLa JollaUnited States
| | - Aleš Horák
- Biology Centre CAS, Institute of ParasitologyČeské BudějoviceCzech Republic
- University of South Bohemia, Faculty of ScienceČeské BudějoviceCzech Republic
| | - Miroslav Oborník
- Biology Centre CAS, Institute of ParasitologyČeské BudějoviceCzech Republic
- University of South Bohemia, Faculty of ScienceČeské BudějoviceCzech Republic
| | - Vincent A Bielinski
- Synthetic Biology and Bioenergy, J. Craig Venter InstituteLa JollaUnited States
| | - Andrew Ellis Allen
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San DiegoLa JollaUnited States
- Microbial and Environmental Genomics, J. Craig Venter InstituteLa JollaUnited States
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23
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Cheng H, Shao Z, Lu C, Duan D. Genome-wide identification of chitinase genes in Thalassiosira pseudonana and analysis of their expression under abiotic stresses. BMC PLANT BIOLOGY 2021; 21:87. [PMID: 33568068 PMCID: PMC7874618 DOI: 10.1186/s12870-021-02849-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND The nitrogen-containing polysaccharide chitin is the second most abundant biopolymer on earth and is found in the cell walls of diatoms, where it serves as a scaffold for biosilica deposition. Diatom chitin is an important source of carbon and nitrogen in the marine environment, but surprisingly little is known about basic chitinase metabolism in diatoms. RESULTS Here, we identify and fully characterize 24 chitinase genes from the model centric diatom Thalassiosira pseudonana. We demonstrate that their expression is broadly upregulated under abiotic stresses, despite the fact that chitinase activity itself remains unchanged, and we discuss several explanations for this result. We also examine the potential transcriptional complexity of the intron-rich T. pseudonana chitinase genes and provide evidence for two separate tandem duplication events during their evolution. CONCLUSIONS Given the many applications of chitin and chitin derivatives in suture production, wound healing, drug delivery, and other processes, new insight into diatom chitin metabolism has both theoretical and practical value.
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Affiliation(s)
- Haomiao Cheng
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, P. R. China
- Laboratory for Marine Biology and Biotechnology, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhanru Shao
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, P. R. China.
- Laboratory for Marine Biology and Biotechnology, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, P. R. China.
| | - Chang Lu
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, P. R. China
- Laboratory for Marine Biology and Biotechnology, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Delin Duan
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, P. R. China.
- Laboratory for Marine Biology and Biotechnology, Pilot Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, P. R. China.
- State Key Laboratory of Bioactive Seaweed Substances, Qingdao Bright Moon Seaweed Group Co Ltd, Qingdao, 266400, P. R. China.
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24
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Divergence of photosynthetic strategies amongst marine diatoms. PLoS One 2020; 15:e0244252. [PMID: 33370327 PMCID: PMC7769462 DOI: 10.1371/journal.pone.0244252] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/07/2020] [Indexed: 11/19/2022] Open
Abstract
Marine phytoplankton, and in particular diatoms, are responsible for almost half of all primary production on Earth. Diatom species thrive from polar to tropical waters and across light environments that are highly complex to relatively benign, and so have evolved highly divergent strategies for regulating light capture and utilization. It is increasingly well established that diatoms have achieved such successful ecosystem dominance by regulating excitation energy available for generating photosynthetic energy via highly flexible light harvesting strategies. However, how different light harvesting strategies and downstream pathways for oxygen production and consumption interact to balance excitation pressure remains unknown. We therefore examined the responses of three diatom taxa adapted to inherently different light climates (estuarine Thalassioisira weissflogii, coastal Thalassiosira pseudonana and oceanic Thalassiosira oceanica) during transient shifts from a moderate to high growth irradiance (85 to 1200 μmol photons m-2 s-1). Transient high light exposure caused T. weissflogii to rapidly downregulate PSII with substantial nonphotochemical quenching, protecting PSII from inactivation or damage, and obviating the need for induction of O2 consuming (light-dependent respiration, LDR) pathways. In contrast, T. oceanica retained high excitation pressure on PSII, but with little change in RCII photochemical turnover, thereby requiring moderate repair activity and greater reliance on LDR. T. pseudonana exhibited an intermediate response compared to the other two diatom species, exhibiting some downregulation and inactivation of PSII, but high repair of PSII and induction of reversible PSII nonphotochemical quenching, with some LDR. Together, these data demonstrate a range of strategies for balancing light harvesting and utilization across diatom species, which reflect their adaptation to sustain photosynthesis under environments with inherently different light regimes.
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Pierangelini M, Thiry M, Cardol P. Different levels of energetic coupling between photosynthesis and respiration do not determine the occurrence of adaptive responses of Symbiodiniaceae to global warming. THE NEW PHYTOLOGIST 2020; 228:855-868. [PMID: 32535971 PMCID: PMC7590187 DOI: 10.1111/nph.16738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 05/30/2020] [Indexed: 05/06/2023]
Abstract
Disentangling the metabolic functioning of corals' endosymbionts (Symbiodiniaceae) is relevant to understanding the response of coral reefs to warming oceans. In this work, we first question whether there is an energetic coupling between photosynthesis and respiration in Symbiodiniaceae (Symbiodinium, Durusdinium and Effrenium), and second, how different levels of energetic coupling will affect their adaptive responses to global warming. Coupling between photosynthesis and respiration was established by determining the variation of metabolic rates during thermal response curves, and how inhibition of respiration affects photosynthesis. Adaptive (irreversible) responses were studied by exposing two Symbiodinium species with different levels of photosynthesis-respiration interaction to high temperature conditions (32°C) for 1 yr. We found that some Symbiodiniaceae have a high level of energetic coupling; that is, photosynthesis and respiration have the same temperature dependency, and photosynthesis is negatively affected when respiration is inhibited. Conversely, photosynthesis and respiration are not coupled in other species. In any case, prolonged exposure to high temperature caused adjustments in both photosynthesis and respiration, but these changes were fully reversible. We conclude that energetic coupling between photosynthesis and respiration exhibits wide variation amongst Symbiodiniaceae and does not determine the occurrence of adaptive responses in Symbiodiniaceae to temperature increase.
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Affiliation(s)
- Mattia Pierangelini
- Génétique et Physiologie des MicroalguesInBioS/PhytosystemsInstitut de BotaniqueUniversité de LiègeB22Liège4000Belgium
| | - Marc Thiry
- Unit of Cell BiologyGIGA‐NeurosciencesCHU Sart‐TilmanUniversity of LiègeLiègeB36, 4000Belgium
| | - Pierre Cardol
- Génétique et Physiologie des MicroalguesInBioS/PhytosystemsInstitut de BotaniqueUniversité de LiègeB22Liège4000Belgium
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26
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Young JN, Schmidt K. It's what's inside that matters: physiological adaptations of high-latitude marine microalgae to environmental change. THE NEW PHYTOLOGIST 2020; 227:1307-1318. [PMID: 32391569 DOI: 10.1111/nph.16648] [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: 08/23/2019] [Accepted: 03/23/2020] [Indexed: 05/13/2023]
Abstract
Marine microalgae within seawater and sea ice fuel high-latitude ecosystems and drive biogeochemical cycles through the fixation and export of carbon, uptake of nutrients, and production and release of oxygen and organic compounds. High-latitude marine environments are characterized by cold temperatures, dark winters and a strong seasonal cycle. Within this environment a number of diverse and dynamic habitats exist, particularly in association with the formation and melt of sea ice, with distinct microalgal communities that transition with the season. Algal physiology is a crucial component, both responding to the dynamic environment and in turn influencing its immediate physicochemical environment. As high-latitude oceans shift into new climate regimes the analysis of seasonal responses may provide insights into how microalgae will respond to long-term environmental change. This review discusses recent developments in our understanding of how the physiology of high-latitude marine microalgae is regulated over a polar seasonal cycle, with a focus on ice-associated (sympagic) algae. In particular, physiologies that impact larger scale processes will be explored, with an aim to improve our understanding of current and future ecosystems and biogeochemical cycles.
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Affiliation(s)
- Jodi N Young
- School of Oceanography, University of Washington, Seattle, WA, 98195, USA
| | - Katrin Schmidt
- School of Oceanography, University of Washington, Seattle, WA, 98195, USA
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27
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González-Fernández C, Le Grand F, Bideau A, Huvet A, Paul-Pont I, Soudant P. Nanoplastics exposure modulate lipid and pigment compositions in diatoms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 262:114274. [PMID: 32135430 DOI: 10.1016/j.envpol.2020.114274] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 02/07/2020] [Accepted: 02/24/2020] [Indexed: 06/10/2023]
Abstract
The impact of nanoplastics (NP) using model polystyrene nanoparticles amine functionalized (PS-NH2) has been investigated on pigment and lipid compositions of the marine diatom Chaetoceros neogracile, at two growth phases using a low (0.05 μg mL-1) and a high (5 μg mL-1) concentrations for 96 h. Results evidenced an impact on pigment composition associated to the light-harvesting function and photoprotection mainly at exponential phase. NP also impacted lipid composition of diatoms with a re-adjustment of lipid classes and fatty acids noteworthy. Main changes upon NP exposure were observed in galactolipids and triacylglycerol's at both growth phases affecting the thylakoids membrane structure and cellular energy reserve of diatoms. Particularly, exponential cultures exposed to high NP concentration showed an impairment of long chain fatty acids synthesis. Changes in pigment and lipid content of diatom' cells revealed that algae physiology is determinant in the way cells adjust their thylakoid membrane composition to cope with NP contamination stress. Compositions of reserve and membrane lipids are proposed as sensitive markers to assess the impact of NP exposure, including at potential predicted environmental doses, on marine organisms.
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Affiliation(s)
- Carmen González-Fernández
- Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, 30100, Murcia, Spain; Laboratoire des Sciences de l'Environnement Marin (LEMAR), Univ. Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France
| | - Fabienne Le Grand
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), Univ. Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France
| | - Antoine Bideau
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), Univ. Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France
| | - Arnaud Huvet
- Ifremer, Laboratoire des Sciences de l'Environnement Marin (LEMAR), CS 10070, 29280, Plouzané, France
| | - Ika Paul-Pont
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), Univ. Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France
| | - Philippe Soudant
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), Univ. Brest, CNRS, IRD, Ifremer, LEMAR, F-29280, Plouzané, France.
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28
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Nieves-Morión M, Flores E, Foster RA. Predicting substrate exchange in marine diatom-heterocystous cyanobacteria symbioses. Environ Microbiol 2020; 22:2027-2052. [PMID: 32281201 DOI: 10.1111/1462-2920.15013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 11/27/2022]
Abstract
In the open ocean, some phytoplankton establish symbiosis with cyanobacteria. Some partnerships involve diatoms as hosts and heterocystous cyanobacteria as symbionts. Heterocysts are specialized cells for nitrogen fixation, and a function of the symbiotic cyanobacteria is to provide the host with nitrogen. However, both partners are photosynthetic and capable of carbon fixation, and the possible metabolites exchanged and mechanisms of transfer are poorly understood. The symbiont cellular location varies from internal to partial to fully external, and this is reflected in the symbiont genome size and content. In order to identify the membrane transporters potentially involved in metabolite exchange, we compare the draft genomes of three differently located symbionts with known transporters mainly from model free-living heterocystous cyanobacteria. The types and numbers of transporters are directly related to the symbiont cellular location: restricted in the endosymbionts and wider in the external symbiont. Three proposed models of metabolite exchange are suggested which take into account the type of transporters in the symbionts and the influence of their cellular location on the available nutrient pools. These models provide a basis for several hypotheses that given the importance of these symbioses in global N and C budgets, warrant future testing.
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Affiliation(s)
- Mercedes Nieves-Morión
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, Seville, E-41092, Spain
| | - Rachel A Foster
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, 106 91, Sweden
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29
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Leyland B, Boussiba S, Khozin-Goldberg I. A Review of Diatom Lipid Droplets. BIOLOGY 2020; 9:biology9020038. [PMID: 32098118 PMCID: PMC7168155 DOI: 10.3390/biology9020038] [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: 12/18/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/20/2022]
Abstract
The dynamic nutrient availability and photon flux density of diatom habitats necessitate buffering capabilities in order to maintain metabolic homeostasis. This is accomplished by the biosynthesis and turnover of storage lipids, which are sequestered in lipid droplets (LDs). LDs are an organelle conserved among eukaryotes, composed of a neutral lipid core surrounded by a polar lipid monolayer. LDs shield the intracellular environment from the accumulation of hydrophobic compounds and function as a carbon and electron sink. These functions are implemented by interconnections with other intracellular systems, including photosynthesis and autophagy. Since diatom lipid production may be a promising objective for biotechnological exploitation, a deeper understanding of LDs may offer targets for metabolic engineering. In this review, we provide an overview of diatom LD biology and biotechnological potential.
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30
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Ifuku K, Yan D. Efficient Transformation of the Diatoms Phaeodactylum tricornutum by Multipulse Electroporation. Methods Mol Biol 2020; 2050:169-174. [PMID: 31468491 DOI: 10.1007/978-1-4939-9740-4_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An efficient nuclear transformation method has been established for the pennate marine diatom Phaeodactylum tricornutum using an electroporation system that drives multisequence pulses to introduce foreign DNAs into the cells. By removing excess salts in the culture medium and optimizing pulse conditions, diatom cells can be transformed with high transformation efficiency. This method is also applicable to other marine diatoms, such as the centric diatom Chaetoceros gracilis. This efficient and stable transformation system will be useful for both functional analysis of diatom-specific genes and for further biotechnological applications.
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Affiliation(s)
- Kentaro Ifuku
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan.
| | - Dongyi Yan
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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31
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Ait-Mohamed O, Novák Vanclová AMG, Joli N, Liang Y, Zhao X, Genovesio A, Tirichine L, Bowler C, Dorrell RG. PhaeoNet: A Holistic RNAseq-Based Portrait of Transcriptional Coordination in the Model Diatom Phaeodactylum tricornutum. FRONTIERS IN PLANT SCIENCE 2020; 11:590949. [PMID: 33178253 PMCID: PMC7596299 DOI: 10.3389/fpls.2020.590949] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/15/2020] [Indexed: 05/04/2023]
Abstract
Transcriptional coordination is a fundamental component of prokaryotic and eukaryotic cell biology, underpinning the cell cycle, physiological transitions, and facilitating holistic responses to environmental stress, but its overall dynamics in eukaryotic algae remain poorly understood. Better understanding of transcriptional partitioning may provide key insights into the primary metabolism pathways of eukaryotic algae, which frequently depend on intricate metabolic associations between the chloroplasts and mitochondria that are not found in plants. Here, we exploit 187 publically available RNAseq datasets generated under varying nitrogen, iron and phosphate growth conditions to understand the co-regulatory principles underpinning transcription in the model diatom Phaeodactylum tricornutum. Using WGCNA (Weighted Gene Correlation Network Analysis), we identify 28 merged modules of co-expressed genes in the P. tricornutum genome, which show high connectivity and correlate well with previous microarray-based surveys of gene co-regulation in this species. We use combined functional, subcellular localization and evolutionary annotations to reveal the fundamental principles underpinning the transcriptional co-regulation of genes implicated in P. tricornutum chloroplast and mitochondrial metabolism, as well as the functions of diverse transcription factors underpinning this co-regulation. The resource is publically available as PhaeoNet, an advanced tool to understand diatom gene co-regulation.
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Affiliation(s)
- Ouardia Ait-Mohamed
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Anna M. G. Novák Vanclová
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Nathalie Joli
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Yue Liang
- Department of Oceanography, Dalhousie University, Halifax, NS, Canada
| | - Xue Zhao
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
- Université de Nantes, CNRS, UFIP, UMR 6286, Nantes, France
| | - Auguste Genovesio
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Leila Tirichine
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
- Université de Nantes, CNRS, UFIP, UMR 6286, Nantes, France
- *Correspondence: Leila Tirichine,
| | - Chris Bowler
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
- Chris Bowler,
| | - Richard G. Dorrell
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
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32
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Smith SR, Dupont CL, McCarthy JK, Broddrick JT, Oborník M, Horák A, Füssy Z, Cihlář J, Kleessen S, Zheng H, McCrow JP, Hixson KK, Araújo WL, Nunes-Nesi A, Fernie A, Nikoloski Z, Palsson BO, Allen AE. Evolution and regulation of nitrogen flux through compartmentalized metabolic networks in a marine diatom. Nat Commun 2019; 10:4552. [PMID: 31591397 PMCID: PMC6779911 DOI: 10.1038/s41467-019-12407-y] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 09/03/2019] [Indexed: 01/15/2023] Open
Abstract
Diatoms outcompete other phytoplankton for nitrate, yet little is known about the mechanisms underpinning this ability. Genomes and genome-enabled studies have shown that diatoms possess unique features of nitrogen metabolism however, the implications for nutrient utilization and growth are poorly understood. Using a combination of transcriptomics, proteomics, metabolomics, fluxomics, and flux balance analysis to examine short-term shifts in nitrogen utilization in the model pennate diatom in Phaeodactylum tricornutum, we obtained a systems-level understanding of assimilation and intracellular distribution of nitrogen. Chloroplasts and mitochondria are energetically integrated at the critical intersection of carbon and nitrogen metabolism in diatoms. Pathways involved in this integration are organelle-localized GS-GOGAT cycles, aspartate and alanine systems for amino moiety exchange, and a split-organelle arginine biosynthesis pathway that clarifies the role of the diatom urea cycle. This unique configuration allows diatoms to efficiently adjust to changing nitrogen status, conferring an ecological advantage over other phytoplankton taxa.
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Affiliation(s)
- Sarah R Smith
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, 92037, USA
| | - Chris L Dupont
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, 92037, USA
| | - James K McCarthy
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, 92037, USA
| | - Jared T Broddrick
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Aleš Horák
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Zoltán Füssy
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Jaromír Cihlář
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Sabrina Kleessen
- Targenomix, GmbH, Wissenschaftspark Potsdam-Golm, 14476, Potsdam, Germany
| | - Hong Zheng
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, 92037, USA
| | - John P McCrow
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, 92037, USA
| | - Kim K Hixson
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
- Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Alisdair Fernie
- Max Planck Institut of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Zoran Nikoloski
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Andrew E Allen
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, 92037, USA.
- Scripps Institution of Oceanography, Integrative Oceanography Division, University of California, San Diego, La Jolla, CA, 92093, USA.
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33
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Schober AF, R�o B�rtulos C, Bischoff A, Lepetit B, Gruber A, Kroth PG. Organelle Studies and Proteome Analyses of Mitochondria and Plastids Fractions from the Diatom Thalassiosira pseudonana. PLANT & CELL PHYSIOLOGY 2019; 60:1811-1828. [PMID: 31179502 PMCID: PMC6683858 DOI: 10.1093/pcp/pcz097] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/14/2019] [Indexed: 05/19/2023]
Abstract
Diatoms are unicellular algae and evolved by secondary endosymbiosis, a process in which a red alga-like eukaryote was engulfed by a heterotrophic eukaryotic cell. This gave rise to plastids of remarkable complex architecture and ultrastructure that require elaborate protein importing, trafficking, signaling and intracellular cross-talk pathways. Studying both plastids and mitochondria and their distinctive physiological pathways in organello may greatly contribute to our understanding of photosynthesis, mitochondrial respiration and diatom evolution. The isolation of such complex organelles, however, is still demanding, and existing protocols are either limited to a few species (for plastids) or have not been reported for diatoms so far (for mitochondria). In this work, we present the first isolation protocol for mitochondria from the model diatom Thalassiosira pseudonana. Apart from that, we extended the protocol so that it is also applicable for the purification of a high-quality plastids fraction, and provide detailed structural and physiological characterizations of the resulting organelles. Isolated mitochondria were structurally intact, showed clear evidence of mitochondrial respiration, but the fractions still contained residual cell fragments. In contrast, plastid isolates were virtually free of cellular contaminants, featured structurally preserved thylakoids performing electron transport, but lost most of their stromal components as concluded from Western blots and mass spectrometry. Liquid chromatography electrospray-ionization mass spectrometry studies on mitochondria and thylakoids, moreover, allowed detailed proteome analyses which resulted in extensive proteome maps for both plastids and mitochondria thus helping us to broaden our understanding of organelle metabolism and functionality in diatoms.
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Affiliation(s)
- Alexander F Schober
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, Germany
- Corresponding author: E-mail, ; Fax, +49(0)7531-88-4047
| | - Carolina R�o B�rtulos
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Annsophie Bischoff
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Bernard Lepetit
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Ansgar Gruber
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, Germany
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovsk� 1160/31, Česk� Budějovice, Czech Republic
| | - Peter G Kroth
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, Germany
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34
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Kennedy F, Martin A, Bowman JP, Wilson R, McMinn A. Dark metabolism: a molecular insight into how the Antarctic sea-ice diatom Fragilariopsis cylindrus survives long-term darkness. THE NEW PHYTOLOGIST 2019; 223:675-691. [PMID: 30985935 PMCID: PMC6617727 DOI: 10.1111/nph.15843] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/02/2019] [Indexed: 05/27/2023]
Abstract
Light underneath Antarctic sea-ice is below detectable limits for up to 4 months of the year. The ability of Antarctic sea-ice diatoms to survive this prolonged darkness relies on their metabolic capability. This study is the first to examine the proteome of a prominent sea-ice diatom in response to extended darkness, focusing on the protein-level mechanisms of dark survival. The Antarctic diatom Fragilariopsis cylindrus was grown under continuous light or darkness for 120 d. The whole cell proteome was quantitatively analysed by nano-LC-MS/MS to investigate metabolic changes that occur during sustained darkness and during recovery under illumination. Enzymes of metabolic pathways, particularly those involved in respiratory processes, tricarboxylic acid cycle, glycolysis, the Entner-Doudoroff pathway, the urea cycle and the mitochondrial electron transport chain became more abundant in the dark. Within the plastid, carbon fixation halted while the upper sections of the glycolysis, gluconeogenesis and pentose phosphate pathways became less active. We have discovered how F. cylindrus utilises an ancient alternative metabolic mechanism that enables its capacity for long-term dark survival. By sustaining essential metabolic processes in the dark, F. cylindrus retains the functionality of the photosynthetic apparatus, ensuring rapid recovery upon re-illumination.
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Affiliation(s)
- Fraser Kennedy
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobart7000TasmaniaAustralia
| | - Andrew Martin
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobart7000TasmaniaAustralia
| | - John P. Bowman
- Centre for Food Safety and InnovationTasmanian Institute of AgricultureHobart7000TasmaniaAustralia
| | - Richard Wilson
- Central Science LaboratoryUniversity of TasmaniaHobart7000TasmaniaAustralia
| | - Andrew McMinn
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobart7000TasmaniaAustralia
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Broddrick JT, Du N, Smith SR, Tsuji Y, Jallet D, Ware MA, Peers G, Matsuda Y, Dupont CL, Mitchell BG, Palsson BO, Allen AE. Cross-compartment metabolic coupling enables flexible photoprotective mechanisms in the diatom Phaeodactylum tricornutum. THE NEW PHYTOLOGIST 2019; 222:1364-1379. [PMID: 30636322 PMCID: PMC6594073 DOI: 10.1111/nph.15685] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 12/20/2018] [Indexed: 05/07/2023]
Abstract
Photoacclimation consists of short- and long-term strategies used by photosynthetic organisms to adapt to dynamic light environments. Observable photophysiology changes resulting from these strategies have been used in coarse-grained models to predict light-dependent growth and photosynthetic rates. However, the contribution of the broader metabolic network, relevant to species-specific strategies and fitness, is not accounted for in these simple models. We incorporated photophysiology experimental data with genome-scale modeling to characterize organism-level, light-dependent metabolic changes in the model diatom Phaeodactylum tricornutum. Oxygen evolution and photon absorption rates were combined with condition-specific biomass compositions to predict metabolic pathway usage for cells acclimated to four different light intensities. Photorespiration, an ornithine-glutamine shunt, and branched-chain amino acid metabolism were hypothesized as the primary intercompartment reductant shuttles for mediating excess light energy dissipation. Additionally, simulations suggested that carbon shunted through photorespiration is recycled back to the chloroplast as pyruvate, a mechanism distinct from known strategies in photosynthetic organisms. Our results suggest a flexible metabolic network in P. tricornutum that tunes intercompartment metabolism to optimize energy transport between the organelles, consuming excess energy as needed. Characterization of these intercompartment reductant shuttles broadens our understanding of energy partitioning strategies in this clade of ecologically important primary producers.
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Affiliation(s)
- Jared T. Broddrick
- Division of Biological SciencesUC San DiegoLa JollaCA92093USA
- Department of BioengineeringUC San DiegoLa JollaCA92093USA
| | - Niu Du
- Scripps Institution of OceanographyUC San DiegoLa JollaCA92093USA
- J. Craig Venter InstituteLa JollaCA92037USA
| | | | - Yoshinori Tsuji
- Department of Environmental BioscienceKwansei Gakuin UniversitySanda669‐1337Japan
| | - Denis Jallet
- Department of BiologyColorado State UniversityFort CollinsCO80523USA
| | - Maxwell A. Ware
- Department of BiologyColorado State UniversityFort CollinsCO80523USA
| | - Graham Peers
- Department of BiologyColorado State UniversityFort CollinsCO80523USA
| | - Yusuke Matsuda
- Department of Environmental BioscienceKwansei Gakuin UniversitySanda669‐1337Japan
| | | | - B. Greg Mitchell
- Scripps Institution of OceanographyUC San DiegoLa JollaCA92093USA
| | | | - Andrew E. Allen
- Scripps Institution of OceanographyUC San DiegoLa JollaCA92093USA
- J. Craig Venter InstituteLa JollaCA92037USA
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36
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Athanasakoglou A, Grypioti E, Michailidou S, Ignea C, Makris AM, Kalantidis K, Massé G, Argiriou A, Verret F, Kampranis SC. Isoprenoid biosynthesis in the diatom Haslea ostrearia. THE NEW PHYTOLOGIST 2019; 222:230-243. [PMID: 30394540 DOI: 10.1111/nph.15586] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/28/2018] [Indexed: 06/08/2023]
Abstract
Diatoms are eukaryotic, unicellular algae that are responsible for c. 20% of the Earth's primary production. Their dominance and success in contemporary oceans have prompted investigations on their distinctive metabolism and physiology. One metabolic pathway that remains largely unexplored in diatoms is isoprenoid biosynthesis, which is responsible for the production of numerous molecules with unique features. We selected the diatom species Haslea ostrearia because of its characteristic isoprenoid content and carried out a comprehensive transcriptomic analysis and functional characterization of the genes identified. We functionally characterized one farnesyl diphosphate synthase, two geranylgeranyl diphosphate synthases, one short-chain polyprenyl synthase, one bifunctional isopentenyl diphosphate isomerase - squalene synthase, and one phytoene synthase. We inferred the phylogenetic origin of these genes and used a combination of functional analysis and subcellular localization predictions to propose their physiological roles. Our results provide insight into isoprenoid biosynthesis in H. ostrearia and propose a model of the central steps of the pathway. This model will facilitate the study of metabolic pathways of important isoprenoids in diatoms, including carotenoids, sterols and highly branched isoprenoids.
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Affiliation(s)
- Anastasia Athanasakoglou
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, 1871, Denmark
| | - Emilia Grypioti
- Department of Biology, University of Crete, PO Box 2208, Heraklion, 71003, Greece
| | - Sofia Michailidou
- Institute of Applied Biosciences - Centre for Research and Technology Hellas (INAB-CERTH), 6th km. Charilaou - Thermi Road, PO Box 60361, Thermi, Thessaloniki, 57001, Greece
| | - Codruta Ignea
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, 1871, Denmark
| | - Antonios M Makris
- Institute of Applied Biosciences - Centre for Research and Technology Hellas (INAB-CERTH), 6th km. Charilaou - Thermi Road, PO Box 60361, Thermi, Thessaloniki, 57001, Greece
| | - Kriton Kalantidis
- Department of Biology, University of Crete, PO Box 2208, Heraklion, 71003, Greece
- Institute of Molecular Biology and Biotechnology - Foundation of Research and Technology Hellas (IMBB-FORTH), Nikolaou Plastira 100, Heraklion, Crete, GR-70013, Greece
| | - Guillaume Massé
- UMI 3376 TAKUVIK, Centre national de la recherche scientifique (CNRS), Paris, France
- Département de Biologie, Université Laval, Québec, QC, Canada
| | - Anagnostis Argiriou
- Institute of Applied Biosciences - Centre for Research and Technology Hellas (INAB-CERTH), 6th km. Charilaou - Thermi Road, PO Box 60361, Thermi, Thessaloniki, 57001, Greece
| | - Frederic Verret
- Department of Biology, University of Crete, PO Box 2208, Heraklion, 71003, Greece
| | - Sotirios C Kampranis
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg C, 1871, Denmark
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Murik O, Tirichine L, Prihoda J, Thomas Y, Araújo WL, Allen AE, Fernie AR, Bowler C. Downregulation of mitochondrial alternative oxidase affects chloroplast function, redox status and stress response in a marine diatom. THE NEW PHYTOLOGIST 2019; 221:1303-1316. [PMID: 30216452 DOI: 10.1111/nph.15479] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 09/03/2018] [Indexed: 05/20/2023]
Abstract
Diatom dominance in contemporary aquatic environments indicates that they have developed unique and effective mechanisms to cope with the rapid and considerable fluctuations that characterize these environments. In view of their evolutionary history from a secondary endosymbiosis, inter-organellar regulation of biochemical activities may be of particular relevance. Diatom mitochondrial alternative oxidase (AOX) is believed to play a significant role in supplying chloroplasts with ATP produced in the mitochondria. Using the model diatom Phaeodactylum tricornutum we generated AOX knockdown lines, and followed sensitivity to stressors, photosynthesis and transcriptome and metabolome profiles of wild-type and knockdown lines. We show here that expression of the AOX gene is upregulated by various stresses including H2 O2 , heat, high light illumination, and iron or nitrogen limitation. AOX knockdown results in hypersensitivity to stress. Knockdown lines also show significantly reduced photosynthetic rates and their chloroplasts are more oxidized. Comparisons of transcriptome and metabolome profiles suggest a strong impact of AOX activity on gene expression, which is carried through to the level of the metabolome. Our data provide evidence for the involvement of mitochondrial AOX in processes central to the cell biology of diatoms, revealing that cross-talk between mitochondria and chloroplasts is crucial for maintaining sensitivity to changing environments.
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Affiliation(s)
- Omer Murik
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Leila Tirichine
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Judit Prihoda
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Yann Thomas
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
| | - Wagner L Araújo
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Andrew E Allen
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, 92037, USA
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, 92037, USA
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Chris Bowler
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, Université PSL, 75005, Paris, France
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38
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Ovide C, Kiefer-Meyer MC, Bérard C, Vergne N, Lecroq T, Plasson C, Burel C, Bernard S, Driouich A, Lerouge P, Tournier I, Dauchel H, Bardor M. Comparative in depth RNA sequencing of P. tricornutum's morphotypes reveals specific features of the oval morphotype. Sci Rep 2018; 8:14340. [PMID: 30254372 PMCID: PMC6156597 DOI: 10.1038/s41598-018-32519-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 08/21/2018] [Indexed: 11/09/2022] Open
Abstract
Phaeodactylum tricornutum is the most studied diatom encountered principally in coastal unstable environments. It has been hypothesized that the great adaptability of P. tricornutum is probably due to its pleomorphism. Indeed, P. tricornutum is an atypical diatom since it can display three morphotypes: fusiform, triradiate and oval. Currently, little information is available regarding the physiological significance of this morphogenesis. In this study, we adapted P. tricornutum Pt3 strain to obtain algal culture particularly enriched in one dominant morphotype: fusiform, triradiate or oval. These cultures were used to run high-throughput RNA-Sequencing. The whole mRNA transcriptome of each morphotype was determined. Pairwise comparisons highlighted biological processes and molecular functions which are up- and down-regulated. Finally, intersection analysis allowed us to identify the specific features from the oval morphotype which is of particular interest as it is often described to be more resistant to stresses. This study represent the first transcriptome wide characterization of the three morphotypes from P. tricornutum performed on cultures specifically enriched issued from the same Pt3 strain. This work represents an important step for the understanding of the morphogenesis in P. tricornutum and highlights the particular features of the oval morphotype.
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Affiliation(s)
- Clément Ovide
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | | | - Caroline Bérard
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France
| | - Nicolas Vergne
- Normandie Univ, UNIROUEN, LMRS UMR 6085 CNRS, 76000, Rouen, France
| | - Thierry Lecroq
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France
| | - Carole Plasson
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Carole Burel
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Sophie Bernard
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Plate-forme PRIMACEN, 76000, Rouen, France
| | - Azeddine Driouich
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Plate-forme PRIMACEN, 76000, Rouen, France
| | - Patrice Lerouge
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Isabelle Tournier
- Normandie Univ, UNIROUEN, Inserm U1079, IRIB Genomic Facility, 76000, Rouen, France
| | - Hélène Dauchel
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France.
| | - Muriel Bardor
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France. .,Institut Universitaire de France (IUF), Paris, France.
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Marchand J, Heydarizadeh P, Schoefs B, Spetea C. Ion and metabolite transport in the chloroplast of algae: lessons from land plants. Cell Mol Life Sci 2018; 75:2153-2176. [PMID: 29541792 PMCID: PMC5948301 DOI: 10.1007/s00018-018-2793-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 03/01/2018] [Accepted: 03/07/2018] [Indexed: 12/28/2022]
Abstract
Chloroplasts are endosymbiotic organelles and play crucial roles in energy supply and metabolism of eukaryotic photosynthetic organisms (algae and land plants). They harbor channels and transporters in the envelope and thylakoid membranes, mediating the exchange of ions and metabolites with the cytosol and the chloroplast stroma and between the different chloroplast subcompartments. In secondarily evolved algae, three or four envelope membranes surround the chloroplast, making more complex the exchange of ions and metabolites. Despite the importance of transport proteins for the optimal functioning of the chloroplast in algae, and that many land plant homologues have been predicted, experimental evidence and molecular characterization are missing in most cases. Here, we provide an overview of the current knowledge about ion and metabolite transport in the chloroplast from algae. The main aspects reviewed are localization and activity of the transport proteins from algae and/or of homologues from other organisms including land plants. Most chloroplast transporters were identified in the green alga Chlamydomonas reinhardtii, reside in the envelope and participate in carbon acquisition and metabolism. Only a few identified algal transporters are located in the thylakoid membrane and play role in ion transport. The presence of genes for putative transporters in green algae, red algae, diatoms, glaucophytes and cryptophytes is discussed, and roles in the chloroplast are suggested. A deep knowledge in this field is required because algae represent a potential source of biomass and valuable metabolites for industry, medicine and agriculture.
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Affiliation(s)
- Justine Marchand
- Metabolism, Bioengineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML, FR 3473 CNRS, Le Mans University, 72000, Le Mans, France
| | - Parisa Heydarizadeh
- Metabolism, Bioengineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML, FR 3473 CNRS, Le Mans University, 72000, Le Mans, France
| | - Benoît Schoefs
- Metabolism, Bioengineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML, FR 3473 CNRS, Le Mans University, 72000, Le Mans, France.
| | - Cornelia Spetea
- Department of Biological and Environmental Sciences, University of Gothenburg, 40530, Göteborg, Sweden.
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40
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d'Ippolito G, Nuzzo G, Sardo A, Manzo E, Gallo C, Fontana A. Lipoxygenases and Lipoxygenase Products in Marine Diatoms. Methods Enzymol 2018; 605:69-100. [PMID: 29909839 DOI: 10.1016/bs.mie.2018.02.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Marine diatoms negatively affect reproduction and later larval development of dominant zooplankton grazers such as copepods, thereby lowering the recruitment of the next generations of these small crustaceans that are a major food source for larval fish species. The phenomenon has been explained in terms of chemical defense due to grazer-induced synthesis of oxylipins, lipoxygenase-derived oxygenated fatty acid derivatives. Since this first report, studies about diatom oxylipins have multiplied and broadened toward other aspects concerning bloom dynamics, cell growth, and cell differentiation. Diatom oxylipins embrace a number of diverse structures that are recognized as chemical signals in ecological and physiological processes in many other organisms. In diatoms, the most studied examples include polyunsaturated aldehydes (PUAs) and nonvolatile oxylipins (NVOs). The purpose of this chapter is to provide the analytical tools to deal with identification, analysis and biosynthesis of these compounds. Emphasis is given to identification of the enzymatic steps and characterization of the species-specific lipoxygenases even in absence of the availability of molecular information.
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Affiliation(s)
- Giuliana d'Ippolito
- National Research Council of Italy, Institute of Biomolecular Chemistry, Pozzuoli, Naples, Italy
| | - Genoveffa Nuzzo
- National Research Council of Italy, Institute of Biomolecular Chemistry, Pozzuoli, Naples, Italy
| | - Angela Sardo
- National Research Council of Italy, Institute of Biomolecular Chemistry, Pozzuoli, Naples, Italy
| | - Emiliano Manzo
- National Research Council of Italy, Institute of Biomolecular Chemistry, Pozzuoli, Naples, Italy
| | - Carmela Gallo
- National Research Council of Italy, Institute of Biomolecular Chemistry, Pozzuoli, Naples, Italy
| | - Angelo Fontana
- National Research Council of Italy, Institute of Biomolecular Chemistry, Pozzuoli, Naples, Italy.
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41
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Benoiston AS, Ibarbalz FM, Bittner L, Guidi L, Jahn O, Dutkiewicz S, Bowler C. The evolution of diatoms and their biogeochemical functions. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0397. [PMID: 28717023 DOI: 10.1098/rstb.2016.0397] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2017] [Indexed: 11/12/2022] Open
Abstract
In contemporary oceans diatoms are an important group of eukaryotic phytoplankton that typically dominate in upwelling regions and at high latitudes. They also make significant contributions to sporadic blooms that often occur in springtime. Recent surveys have revealed global information about their abundance and diversity, as well as their contributions to biogeochemical cycles, both as primary producers of organic material and as conduits facilitating the export of carbon and silicon to the ocean interior. Sequencing of diatom genomes is revealing the evolutionary underpinnings of their ecological success by examination of their gene repertoires and the mechanisms they use to adapt to environmental changes. The rise of the diatoms over the last hundred million years is similarly being explored through analysis of microfossils and biomarkers that can be traced through geological time, as well as their contributions to seafloor sediments and fossil fuel reserves. The current review aims to synthesize current information about the evolution and biogeochemical functions of diatoms as they rose to prominence in the global ocean.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.
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Affiliation(s)
- Anne-Sophie Benoiston
- Sorbonne Universités, UPMC Univ. Paris 06, Univ. Antilles, Univ. Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), 75005 Paris, France
| | - Federico M Ibarbalz
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR8197, INSERM U1024, 46 rue d'Ulm, 75005 Paris, France
| | - Lucie Bittner
- Sorbonne Universités, UPMC Univ. Paris 06, Univ. Antilles, Univ. Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), 75005 Paris, France
| | - Lionel Guidi
- Sorbonne Universités, UPMC Univ. Paris 06, CNRS, Laboratoire d'Océanographie de Villefranche (LOV) UMR7093, Observatoire Océanologique, 06230 Villefranche-sur-Mer, France.,Department of Oceanography, University of Hawaii, Honolulu, HI 96822, USA
| | - Oliver Jahn
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 54-1514 MIT, Cambridge, MA 02139, USA
| | - Stephanie Dutkiewicz
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 54-1514 MIT, Cambridge, MA 02139, USA
| | - Chris Bowler
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR8197, INSERM U1024, 46 rue d'Ulm, 75005 Paris, France
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Young JN, Hopkinson BM. The potential for co-evolution of CO2-concentrating mechanisms and Rubisco in diatoms. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3751-3762. [PMID: 28645158 DOI: 10.1093/jxb/erx130] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Diatoms are a diverse group of unicellular algae that contribute significantly to global photosynthetic carbon fixation and export in the modern ocean, and are an important source of microfossils for paleoclimate reconstructions. Because of their importance in the environment, diatoms have been a focus of study on the physiology and ecophysiology of carbon fixation, in particular their CO2-concentrating mechanisms (CCMs) and Rubisco characteristics. While carbon fixation in diatoms is not as well understood as in certain model aquatic photoautotrophs, a greater number of species have been examined in diatoms. Recent work has highlighted a large diversity in the function, physiology, and kinetics of both the CCM and Rubisco between different diatom species. This diversity was unexpected since it has generally been assumed that CCMs and Rubiscos were similar within major algal lineages as the result of selective events deep in evolutionary history, and suggests a more recent co-evolution between the CCM and Rubisco within diatoms. This review explores our current understanding of the diatom CCM and highlights the diversity of both the CCM and Rubisco kinetics. We will suggest possible environmental, physiological, and evolutionary drivers for the co-evolution of the CCM and Rubisco in diatoms.
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Affiliation(s)
- Jodi N Young
- University of Washington, School of Oceanography, Seattle, WA 98105, USA
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43
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Kamikawa R, Moog D, Zauner S, Tanifuji G, Ishida KI, Miyashita H, Mayama S, Hashimoto T, Maier UG, Archibald JM, Inagaki Y. A Non-photosynthetic Diatom Reveals Early Steps of Reductive Evolution in Plastids. Mol Biol Evol 2017; 34:2355-2366. [DOI: 10.1093/molbev/msx172] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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44
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Li G, Talmy D, Campbell DA. Diatom growth responses to photoperiod and light are predictable from diel reductant generation. JOURNAL OF PHYCOLOGY 2017; 53:95-107. [PMID: 27754547 PMCID: PMC5363399 DOI: 10.1111/jpy.12483] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 09/13/2016] [Indexed: 05/11/2023]
Abstract
Light drives phytoplankton productivity, so phytoplankton must exploit variable intensities and durations of light exposure, depending upon season, latitude, and depth. We analyzed the growth, photophysiology and composition of small, Thalassiosira pseudonana, and large, Thalassiosira punctigera, centric diatoms from temperate, coastal marine habitats, responding to a matrix of photoperiods and growth light intensities. T. pseudonana showed fastest growth rates under long photoperiods and low to moderate light intensities, while the larger T. punctigera showed fastest growth rates under short photoperiods and higher light intensities. Photosystem II function and content responded primarily to instantaneous growth light intensities during the photoperiod, while diel carbon fixation and RUBISCO content responded more to photoperiod duration than to instantaneous light intensity. Changing photoperiods caused species-specific changes in the responses of photochemical yield (e- /photon) to growth light intensity. These photophysiological variables showed complex responses to photoperiod and to growth light intensity. Growth rate also showed complex responses to photoperiod and growth light intensity. But these complex responses resolved into a close relation between growth rate and the cumulative daily generation of reductant, across the matrix of photoperiods and light intensities.
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Affiliation(s)
- Gang Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - David Talmy
- Department of Earth, Atmosphere and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts, 02139, USA
| | - Douglas A Campbell
- Department of Biology, Mount Allison University, 63B York St., Sackville, New Brunswick, Canada
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45
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Liu X, Hempel F, Stork S, Bolte K, Moog D, Heimerl T, Maier UG, Zauner S. Addressing various compartments of the diatom model organism Phaeodactylum tricornutum via sub-cellular marker proteins. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.10.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Kamp A, Stief P, Bristow LA, Thamdrup B, Glud RN. Intracellular Nitrate of Marine Diatoms as a Driver of Anaerobic Nitrogen Cycling in Sinking Aggregates. Front Microbiol 2016; 7:1669. [PMID: 27847498 PMCID: PMC5088207 DOI: 10.3389/fmicb.2016.01669] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/06/2016] [Indexed: 01/20/2023] Open
Abstract
Diatom-bacteria aggregates are key for the vertical transport of organic carbon in the ocean. Sinking aggregates also represent pelagic microniches with intensified microbial activity, oxygen depletion in the center, and anaerobic nitrogen cycling. Since some of the aggregate-forming diatom species store nitrate intracellularly, we explored the fate of intracellular nitrate and its availability for microbial metabolism within anoxic diatom-bacteria aggregates. The ubiquitous nitrate-storing diatom Skeletonema marinoi was studied as both axenic cultures and laboratory-produced diatom-bacteria aggregates. Stable 15N isotope incubations under dark and anoxic conditions revealed that axenic S. marinoi is able to reduce intracellular nitrate to ammonium that is immediately excreted by the cells. When exposed to a light:dark cycle and oxic conditions, S. marinoi stored nitrate intracellularly in concentrations >60 mmol L-1 both as free-living cells and associated to aggregates. Intracellular nitrate concentrations exceeded extracellular concentrations by three orders of magnitude. Intracellular nitrate was used up within 2-3 days after shifting diatom-bacteria aggregates to dark and anoxic conditions. Thirty-one percent of the diatom-derived nitrate was converted to nitrogen gas, indicating that a substantial fraction of the intracellular nitrate pool of S. marinoi becomes available to the aggregate-associated bacterial community. Only 5% of the intracellular nitrate was reduced to ammonium, while 59% was recovered as nitrite. Hence, aggregate-associated diatoms accumulate nitrate from the surrounding water and sustain complex nitrogen transformations, including loss of fixed nitrogen, in anoxic, pelagic microniches. Additionally, it may be expected that intracellular nitrate not converted before the aggregates have settled onto the seafloor could fuel benthic nitrogen transformations.
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Affiliation(s)
- Anja Kamp
- AIAS, Aarhus Institute of Advanced Studies, Aarhus UniversityAarhus, Denmark
| | - Peter Stief
- Department of Biology and Nordic Center for Earth Evolution, University of Southern DenmarkOdense, Denmark
| | - Laura A. Bristow
- Department of Biology and Nordic Center for Earth Evolution, University of Southern DenmarkOdense, Denmark
- Department of Biogeochemistry, Max Planck Institute for Marine MicrobiologyBremen, Germany
| | - Bo Thamdrup
- Department of Biology and Nordic Center for Earth Evolution, University of Southern DenmarkOdense, Denmark
| | - Ronnie N. Glud
- Department of Biology and Nordic Center for Earth Evolution, University of Southern DenmarkOdense, Denmark
- Department of Biogeochemistry and Earth Science, Scottish Association for Marine ScienceOban, UK
- Department of Bioscience, Arctic Research Centre, Aarhus UniversityAarhus, Denmark
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Davis A, Abbriano R, Smith SR, Hildebrand M. Clarification of Photorespiratory Processes and the Role of Malic Enzyme in Diatoms. Protist 2016; 168:134-153. [PMID: 28104538 DOI: 10.1016/j.protis.2016.10.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 10/03/2016] [Accepted: 10/08/2016] [Indexed: 11/20/2022]
Abstract
Evidence suggests that diatom photorespiratory metabolism is distinct from other photosynthetic eukaryotes in that there may be at least two routes for the metabolism of the photorespiratory metabolite glycolate. One occurs primarily in the mitochondria and is similar to the C2 photorespiratory pathway, and the other processes glycolate through the peroxisomal glyoxylate cycle. Genomic analysis has identified the presence of key genes required for glycolate oxidation, the glyoxylate cycle, and malate metabolism, however, predictions of intracellular localization can be ambiguous and require verification. This knowledge gap leads to uncertainties surrounding how these individual pathways operate, either together or independently, to process photorespiratory intermediates under different environmental conditions. Here, we combine in silico sequence analysis, in vivo protein localization techniques and gene expression patterns to investigate key enzymes potentially involved in photorespiratory metabolism in the model diatom Thalassiosira pseudonana. We demonstrate the peroxisomal localization of isocitrate lyase and the mitochondrial localization of malic enzyme and a glycolate oxidase. Based on these analyses, we propose an updated model for photorespiratory metabolism in T. pseudonana, as well as a mechanism by which C2 photorespiratory metabolism and its associated pathways may operate during silicon starvation and growth arrest.
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Affiliation(s)
- Aubrey Davis
- Marine Biology Research Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, U.S.A
| | - Raffaela Abbriano
- Marine Biology Research Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, U.S.A
| | - Sarah R Smith
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, U.S.A.; J. Craig Venter Institute, La Jolla, CA, U.S.A
| | - Mark Hildebrand
- Marine Biology Research Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, U.S.A..
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Fisher NL, Halsey KH. Mechanisms that increase the growth efficiency of diatoms in low light. PHOTOSYNTHESIS RESEARCH 2016; 129:183-97. [PMID: 27312336 DOI: 10.1007/s11120-016-0282-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 06/07/2016] [Indexed: 05/28/2023]
Abstract
Photoacclimation was studied in Thalassiosira pseudonana to help understand mechanisms underlying the success of diatoms in low-light environments, such as coastal and deep mixing ecosystems. Light harvesting and other cell characteristics were combined with oxygen and carbon production measurements to assess the water-splitting reaction at PSII ([Formula: see text]) and intermediate steps leading to net carbon production (NPPC). These measurements revealed that T. pseudonana is remarkably efficient at converting harvested light energy into biomass, with at least 57 % of [Formula: see text] retained as NPPC across all light-limited growth rates examined. Evidence for upregulation of ATP generation pathways that circumvent carbon fixation indicated that high growth efficiency at low light levels was at least partly due to increases in the efficiency of ATP production. Growth rate-dependent demands for ATP and NADPH were reflected in carbon composition and in unexpected shifts in the light-limited slope (α) of photosynthesis-irradiance relationships generated from chlorophyll-specific (14)C-uptake. Overall, these results suggest that pathway gating of carbon and energy flow depends on light availability and is a key factor promoting the efficiency of diatom growth at low light intensities.
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Affiliation(s)
- Nerissa L Fisher
- Department of Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, OR, 97331, USA
| | - Kimberly H Halsey
- Department of Microbiology, Oregon State University, 226 Nash Hall, Corvallis, OR, 97331, USA.
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49
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Curien G, Flori S, Villanova V, Magneschi L, Giustini C, Forti G, Matringe M, Petroutsos D, Kuntz M, Finazzi G. The Water to Water Cycles in Microalgae. PLANT & CELL PHYSIOLOGY 2016; 57:1354-1363. [PMID: 26955846 DOI: 10.1093/pcp/pcw048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 02/23/2016] [Indexed: 05/28/2023]
Abstract
In oxygenic photosynthesis, light produces ATP plus NADPH via linear electron transfer, i.e. the in-series activity of the two photosystems: PSI and PSII. This process, however, is thought not to be sufficient to provide enough ATP per NADPH for carbon assimilation in the Calvin-Benson-Bassham cycle. Thus, it is assumed that additional ATP can be generated by alternative electron pathways. These circuits produce an electrochemical proton gradient without NADPH synthesis, and, although they often represent a small proportion of the linear electron flow, they could have a huge importance in optimizing CO2 assimilation. In Viridiplantae, there is a consensus that alternative electron flow comprises cyclic electron flow around PSI and the water to water cycles. The latter processes include photosynthetic O2 reduction via the Mehler reaction at PSI, the plastoquinone terminal oxidase downstream of PSII, photorespiration (the oxygenase activity of Rubisco) and the export of reducing equivalents towards the mitochondrial oxidases, through the malate shuttle. In this review, we summarize current knowledge about the role of the water to water cycles in photosynthesis, with a special focus on their occurrence and physiological roles in microalgae.
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Affiliation(s)
- Gilles Curien
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Serena Flori
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | | | - Leonardo Magneschi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Cécile Giustini
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Giorgio Forti
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Michel Matringe
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Dimitris Petroutsos
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Marcel Kuntz
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'Energie Atomique-Université Grenoble Alpes, UMR 1414 Institut National de la Recherche Agronomique (INRA) Biosciences and Biotechnology Institute of Grenoble (BIG), Commissariat à l'Energie Atomique (CEA) Grenoble, 38054 Grenoble cedex 9, France
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Tajima N, Saitoh K, Sato S, Maruyama F, Ichinomiya M, Yoshikawa S, Kurokawa K, Ohta H, Tabata S, Kuwata A, Sato N. Sequencing and analysis of the complete organellar genomes of Parmales, a closely related group to Bacillariophyta (diatoms). Curr Genet 2016; 62:887-896. [DOI: 10.1007/s00294-016-0598-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 03/25/2016] [Accepted: 03/26/2016] [Indexed: 10/21/2022]
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