1
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Gomes KM, Nunn BL, Chappell PD, Jenkins BD. Subcellular proteomics for determining iron-limited remodeling of plastids in the model diatom Thalassiosira pseudonana (Bacillariophyta). JOURNAL OF PHYCOLOGY 2023; 59:1085-1099. [PMID: 37615442 DOI: 10.1111/jpy.13379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 08/25/2023]
Abstract
Diatoms are important primary producers in the world's oceans, yet their growth is constrained in large regions by low bioavailable iron (Fe). Low-Fe stress-induced limitation of primary production is due to requirements for Fe in components of essential metabolic pathways including photosynthesis and other chloroplast plastid functions. Studies have shown that under low-Fe stress, diatoms alter plastid-specific processes, including components of electron transport. These physiological changes suggest changes of protein content and in protein abundances within the diatom plastid. While in silico predictions provide putative information on plastid-localized proteins, knowledge of diatom plastid proteins remains limited in comparison to well-studied model photosynthetic organisms. To address this, we employed shotgun proteomics to investigate the proteome of subcellular plastid-enriched fractions from Thalassiosira pseudonana to gain a better understanding of how the plastid proteome is remodeled in response to Fe limitation. Using mass spectrometry-based peptide identification and quantification, we analyzed T. pseudonana grown under Fe-replete and -limiting conditions. Through these analyses, we inferred the relative quantities of each protein, revealing that Fe limitation regulates major metabolic pathways in the plastid, including the Calvin cycle. Additionally, we observed changes in the expression of light-harvesting proteins. In silico localization predictions of proteins identified in this plastid-enriched proteome allowed for an in-depth comparison of theoretical versus observed plastid-localization, providing evidence for the potential of additional protein import pathways into the diatom plastid.
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Affiliation(s)
- Kristofer M Gomes
- Department of Biological Sciences, University of Rhode Island, Rhode Island, Kingston, USA
| | - Brook L Nunn
- Department of Genome Sciences, University of Washington, Washington, Seattle, USA
| | - P Dreux Chappell
- College of Marine Science, University of South Florida, Florida, St. Petersburg, USA
| | - Bethany D Jenkins
- Department of Cell and Molecular Biology, University of Rhode Island, Rhode Island, Kingston, USA
- Graduate School of Oceanography, University of Rhode Island, Rhode Island, Narragansett, USA
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2
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Castell C, Díaz-Santos E, Heredia-Martínez LG, López-Maury L, Ortega JM, Navarro JA, Roncel M, Hervás M. Iron Deficiency Promotes the Lack of Photosynthetic Cytochrome c550 and Affects the Binding of the Luminal Extrinsic Subunits to Photosystem II in the Diatom Phaeodactylum tricornutum. Int J Mol Sci 2022; 23:ijms232012138. [PMID: 36292994 PMCID: PMC9603157 DOI: 10.3390/ijms232012138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/06/2022] [Accepted: 10/08/2022] [Indexed: 12/04/2022] Open
Abstract
In the diatom Phaeodactylum tricornutum, iron limitation promotes a decrease in the content of photosystem II, as determined by measurements of oxygen-evolving activity, thermoluminescence, chlorophyll fluorescence analyses and protein quantification methods. Thermoluminescence experiments also indicate that iron limitation induces subtle changes in the energetics of the recombination reaction between reduced QB and the S2/S3 states of the water-splitting machinery. However, electron transfer from QA to QB, involving non-heme iron, seems not to be significantly inhibited. Moreover, iron deficiency promotes a severe decrease in the content of the extrinsic PsbV/cytochrome c550 subunit of photosystem II, which appears in eukaryotic algae from the red photosynthetic lineage (including diatoms) but is absent in green algae and plants. The decline in the content of cytochrome c550 under iron-limiting conditions is accompanied by a decrease in the binding of this protein to photosystem II, and also of the extrinsic PsbO subunit. We propose that the lack of cytochrome c550, induced by iron deficiency, specifically affects the binding of other extrinsic subunits of photosystem II, as previously described in cyanobacterial PsbV mutants.
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3
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Fourquez M, Strzepek RF, Ellwood MJ, Hassler C, Cabanes D, Eggins S, Pearce I, Deppeler S, Trull TW, Boyd PW, Bressac M. Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy. Microorganisms 2022; 10:microorganisms10081655. [PMID: 36014073 PMCID: PMC9413495 DOI: 10.3390/microorganisms10081655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
In the Subantarctic sector of the Southern Ocean, vertical entrainment of iron (Fe) triggers the seasonal productivity cycle but diminishing physical supply during the spring to summer transition forces microbial assemblages to rapidly acclimate. Here, we tested how phytoplankton and bacteria within an isolated eddy respond to different dissolved Fe (DFe)/ligand inputs. We used three treatments: one that mimicked the entrainment of new DFe (Fe-NEW), another in which DFe was supplied from bacterial regeneration of particles (Fe-REG), and a control with no addition of DFe (Fe-NO). After 6 days, 3.5 (Fe-NO, Fe-NEW) to 5-fold (Fe-REG) increases in Chlorophyll a were observed. These responses of the phytoplankton community were best explained by the differences between the treatments in the amount of DFe recycled during the incubation (Fe-REG, 15% recycled c.f. 40% Fe-NEW, 60% Fe-NO). This additional recycling was more likely mediated by bacteria. By day 6, bacterial production was comparable between Fe-NO and Fe-NEW but was approximately two-fold higher in Fe-REG. A preferential response of phytoplankton (haptophyte-dominated) relative to high nucleic acid (HNA) bacteria was also found in the Fe-REG treatment while the relative proportion of diatoms increased faster in the Fe-NEW and Fe-NO treatments. Comparisons between light and dark incubations further confirmed the competition between picophytoplankton and HNA for DFe. Overall, our results demonstrate great versatility by microorganisms to use different Fe sources that results in highly efficient Fe recycling within surface waters. This study also encourages future research to further investigate the interactions between functional groups of microbes (e.g. HNA and cyanobacteria) to better constraint modeling in Fe and carbon biogeochemical cycles.
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Affiliation(s)
- Marion Fourquez
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart 7004, Australia
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO UMR 110, 13288 Marseille, France
- Correspondence:
| | - Robert F. Strzepek
- Australian Antarctic Program Partnership (AAPP), Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
| | - Michael J. Ellwood
- Research School of Earth Sciences, Australian National University, Canberra 2601, Australia
| | - Christel Hassler
- Marine and Lake Biogeochemistry, Department F.-A. Forel, University of Geneva, 1205 Geneva, Switzerland
- Institute of Earth Sciences, University of Lausanne, 1015 Lausanne, Switzerland
| | - Damien Cabanes
- Marine and Lake Biogeochemistry, Department F.-A. Forel, University of Geneva, 1205 Geneva, Switzerland
| | - Sam Eggins
- Research School of Earth Sciences, Australian National University, Canberra 2601, Australia
| | - Imojen Pearce
- Australian Antarctic Division (AAD), Kingston 7050, Australia
| | - Stacy Deppeler
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- National Institute of Water and Atmospheric Research, Wellington 6021, New Zealand
| | - Thomas W. Trull
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart 7004, Australia
- Climate Science Centre, Oceans and Atmosphere, Commonwealth Scientific and Industrial Research Organisation, Hobart 7004, Australia
| | - Philip W. Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart 7004, Australia
| | - Matthieu Bressac
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- Laboratoire d’Océanographie de Villefranche, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France
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4
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Strzepek RF, Nunn BL, Bach LT, Berges JA, Young EB, Boyd PW. The ongoing need for rates: can physiology and omics come together to co-design the measurements needed to understand complex ocean biogeochemistry? JOURNAL OF PLANKTON RESEARCH 2022; 44:485-495. [PMID: 35898813 PMCID: PMC9310281 DOI: 10.1093/plankt/fbac026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/05/2022] [Indexed: 05/16/2023]
Abstract
The necessity to understand the influence of global ocean change on biota has exposed wide-ranging gaps in our knowledge of the fundamental principles that underpin marine life. Concurrently, physiological research has stagnated, in part driven by the advent and rapid evolution of molecular biological techniques, such that they now influence all lines of enquiry in biological oceanography. This dominance has led to an implicit assumption that physiology is outmoded, and advocacy that ecological and biogeochemical models can be directly informed by omics. However, the main modeling currencies are biological rates and biogeochemical fluxes. Here, we ask: how do we translate the wealth of information on physiological potential from omics-based studies to quantifiable physiological rates and, ultimately, to biogeochemical fluxes? Based on the trajectory of the state-of-the-art in biomedical sciences, along with case-studies from ocean sciences, we conclude that it is unlikely that omics can provide such rates in the coming decade. Thus, while physiological rates will continue to be central to providing projections of global change biology, we must revisit the metrics we rely upon. We advocate for the co-design of a new generation of rate measurements that better link the benefits of omics and physiology.
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Affiliation(s)
- Robert F Strzepek
- Australian Antarctic Program Partnership (AAPP), Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, TAS 7004, Australia
| | - Brook L Nunn
- Department of Genome Sciences, University of Washington, Foege Building S113 3720 15th Ave NE, Seattle, WA 98195, USA
| | - Lennart T Bach
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7004, Australia
| | - John A Berges
- Department of Biological Sciences and School of Freshwater Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Avenue, Milwaukee, WI 53211, USA
| | - Erica B Young
- Department of Biological Sciences and School of Freshwater Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Avenue, Milwaukee, WI 53211, USA
| | - Philip W Boyd
- Australian Antarctic Program Partnership (AAPP), Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, TAS 7004, Australia
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7004, Australia
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5
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Proteomic traits vary across taxa in a coastal Antarctic phytoplankton bloom. THE ISME JOURNAL 2022; 16:569-579. [PMID: 34482372 PMCID: PMC8776772 DOI: 10.1038/s41396-021-01084-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/13/2021] [Accepted: 08/02/2021] [Indexed: 02/07/2023]
Abstract
Production and use of proteins is under strong selection in microbes, but it is unclear how proteome-level traits relate to ecological strategies. We identified and quantified proteomic traits of eukaryotic microbes and bacteria through an Antarctic phytoplankton bloom using in situ metaproteomics. Different taxa, rather than different environmental conditions, formed distinct clusters based on their ribosomal and photosynthetic proteomic proportions, and we propose that these characteristics relate to ecological differences. We defined and used a proteomic proxy for regulatory cost, which showed that SAR11 had the lowest regulatory cost of any taxa we observed at our summertime Southern Ocean study site. Haptophytes had lower regulatory cost than diatoms, which may underpin haptophyte-to-diatom bloom progression in the Ross Sea. We were able to make these proteomic trait inferences by assessing various sources of bias in metaproteomics, providing practical recommendations for researchers in the field. We have quantified several proteomic traits (ribosomal and photosynthetic proteomic proportions, regulatory cost) in eukaryotic and bacterial taxa, which can then be incorporated into trait-based models of microbial communities that reflect resource allocation strategies.
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6
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Pagnone A, Koch F, Pausch F, Trimborn S. The Southern Ocean diatom Pseudo-nitzschia subcurvata flourished better under simulated glacial than interglacial ocean conditions: Combined effects of CO2 and iron. PLoS One 2021; 16:e0260649. [PMID: 34890411 PMCID: PMC8664213 DOI: 10.1371/journal.pone.0260649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 11/12/2021] [Indexed: 11/19/2022] Open
Abstract
The 'Iron Hypothesis' suggests a fertilization of the Southern Ocean by increased dust deposition in glacial times. This promoted high primary productivity and contributed to lower atmospheric pCO2. In this study, the diatom Pseudo-nitzschia subcurvata, known to form prominent blooms in the Southern Ocean, was grown under simulated glacial and interglacial climatic conditions to understand how iron (Fe) availability (no Fe or Fe addition) in conjunction with different pCO2 levels (190 and 290 μatm) influences growth, particulate organic carbon (POC) production and photophysiology. Under both glacial and interglacial conditions, the diatom grew with similar rates. In comparison, glacial conditions (190 μatm pCO2 and Fe input) favored POC production by P. subcurvata while under interglacial conditions (290 μatm pCO2 and Fe deficiency) POC production was reduced, indicating a negative effect caused by higher pCO2 and low Fe availability. Under interglacial conditions, the diatom had, however, thicker silica shells. Overall, our results show that the combination of higher Fe availability with low pCO2, present during the glacial ocean, was beneficial for the diatom P. subcurvata, thus contributing more to primary production during glacial compared to interglacial times. Under the interglacial ocean conditions, on the other hand, the diatom could have contributed to higher carbon export due to its higher degree of silicification.
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Affiliation(s)
- Anna Pagnone
- EcoTrace, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Florian Koch
- EcoTrace, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Franziska Pausch
- EcoTrace, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Scarlett Trimborn
- EcoTrace, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
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7
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McCain JSP, Tagliabue A, Susko E, Achterberg EP, Allen AE, Bertrand EM. Cellular costs underpin micronutrient limitation in phytoplankton. SCIENCE ADVANCES 2021; 7:7/32/eabg6501. [PMID: 34362734 PMCID: PMC8346223 DOI: 10.1126/sciadv.abg6501] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 06/22/2021] [Indexed: 05/08/2023]
Abstract
Micronutrients control phytoplankton growth in the ocean, influencing carbon export and fisheries. It is currently unclear how micronutrient scarcity affects cellular processes and how interdependence across micronutrients arises. We show that proximate causes of micronutrient growth limitation and interdependence are governed by cumulative cellular costs of acquiring and using micronutrients. Using a mechanistic proteomic allocation model of a polar diatom focused on iron and manganese, we demonstrate how cellular processes fundamentally underpin micronutrient limitation, and how they interact and compensate for each other to shape cellular elemental stoichiometry and resource interdependence. We coupled our model with metaproteomic and environmental data, yielding an approach for estimating biogeochemical metrics, including taxon-specific growth rates. Our results show that cumulative cellular costs govern how environmental conditions modify phytoplankton growth.
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Affiliation(s)
- J Scott P McCain
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Edward Susko
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Eric P Achterberg
- GEOMAR Helmholtz Center for Ocean Research Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany
| | - Andrew E Allen
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA 92037, USA
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92037, USA
| | - Erin M Bertrand
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
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8
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Molecular underpinnings and biogeochemical consequences of enhanced diatom growth in a warming Southern Ocean. Proc Natl Acad Sci U S A 2021; 118:2107238118. [PMID: 34301906 PMCID: PMC8325266 DOI: 10.1073/pnas.2107238118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Phytoplankton contribute to the Southern Ocean’s (SO) ability to absorb atmospheric CO2 and shape the stoichiometry of northward macronutrient delivery. Climate change is altering the SO environment, yet we know little about how resident phytoplankton will react to these changes. Here, we studied a natural SO community and compared responses of two prevalent, bloom-forming diatom groups to changes in temperature and iron that are projected to occur by 2100 to 2300. We found that one group, Pseudo-nitzschia, grows better under warmer low-iron conditions by managing cellular iron demand and efficiently increasing photosynthetic capacity. This ability to grow and draw down nutrients in the face of warming, regardless of iron availability, has major implications for ocean ecosystems and global nutrient cycles. The Southern Ocean (SO) harbors some of the most intense phytoplankton blooms on Earth. Changes in temperature and iron availability are expected to alter the intensity of SO phytoplankton blooms, but little is known about how these changes will influence community composition and downstream biogeochemical processes. We performed light-saturated experimental manipulations on surface ocean microbial communities from McMurdo Sound in the Ross Sea to examine the effects of increased iron availability (+2 nM) and warming (+3 and +6 °C) on nutrient uptake, as well as the growth and transcriptional responses of two dominant diatoms, Fragilariopsis and Pseudo-nitzschia. We found that community nutrient uptake and primary productivity were elevated under both warming conditions without iron addition (relative to ambient −0.5 °C). This effect was greater than additive under concurrent iron addition and warming. Pseudo-nitzschia became more abundant under warming without added iron (especially at 6 °C), while Fragilariopsis only became more abundant under warming in the iron-added treatments. We attribute the apparent advantage Pseudo-nitzschia shows under warming to up-regulation of iron-conserving photosynthetic processes, utilization of iron-economic nitrogen assimilation mechanisms, and increased iron uptake and storage. These data identify important molecular and physiological differences between dominant diatom groups and add to the growing body of evidence for Pseudo-nitzschia’s increasingly important role in warming SO ecosystems. This study also suggests that temperature-driven shifts in SO phytoplankton assemblages may increase utilization of the vast pool of excess nutrients in iron-limited SO surface waters and thereby influence global nutrient distribution and carbon cycling.
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9
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Kong L, Price NM. Transcriptomes of an oceanic diatom reveal the initial and final stages of acclimation to copper deficiency. Environ Microbiol 2021; 24:951-966. [PMID: 34029435 DOI: 10.1111/1462-2920.15609] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/13/2022]
Abstract
Copper (Cu) concentration is greatly reduced in the open sea so that phytoplankton must adjust their uptake systems and acclimate to sustain growth. Acclimation to low Cu involves changes to the photosynthetic apparatus and specific biochemical reactions that use Cu, but little is known how Cu affects cellular metabolic networks. Here we report results of whole transcriptome analysis of a plastocyanin-containing diatom, Thalassiosira oceanica 1005, during its initial stages of acclimation and after long-term adaptation in Cu-deficient seawater. Gene expression profiles, used to identify Cu-regulated metabolic pathways, show downregulation of anabolic and energy-yielding reactions in Cu-limited cells. These include the light reactions of photosynthesis, carbon fixation, nitrogen assimilation and glycolysis. Reduction of these pathways is consistent with reduced growth requirements for C and N caused by slower rates of photosynthetic electron transport. Upregulation of oxidative stress defence systems persists in adapted cells, suggesting cellular damage by increased reactive oxygen species (ROS) occurs even after acclimation. Copper deficiency also alters fatty acid metabolism, possibly in response to an increase in lipid peroxidation and membrane damage driven by ROS. During the initial stages of Cu-limitation the majority of differentially regulated genes are associated with photosynthetic metabolism, highlighting the chloroplast as the primary target of low Cu availability. The results provide insights into the mechanisms of acclimation and adaptation of T. oceanica to Cu deficiency.
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Affiliation(s)
- Liangliang Kong
- Department of Biology, McGill University, Montréal, QC, Canada.,College of Marine Life Sciences, Ocean University of China, Qingdao, Shandong, China
| | - Neil M Price
- Department of Biology, McGill University, Montréal, QC, Canada
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10
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Thangaraj S, Palanisamy SK, Zhang G, Sun J. Quantitative Proteomic Profiling of Marine Diatom Skeletonema dohrnii in Response to Temperature and Silicate Induced Environmental Stress. Front Microbiol 2021; 11:554832. [PMID: 33519723 PMCID: PMC7841394 DOI: 10.3389/fmicb.2020.554832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 12/23/2020] [Indexed: 11/17/2022] Open
Abstract
Global warming is expected to reduce the nutrient concentration in the upper ocean and affect the physiology of marine diatoms, but the underlying molecular mechanisms controlling these physiological changes are currently unknown. To understand these mechanisms, here we investigated iTRAQ based proteomic profiling of diatom Skeletonema dohrnii in a multifactorial experimental with a combining change of temperature and silicate concentrations. In total, 3369 differently abundant proteins were detected in four different environmental conditions, and the function of all proteins was identified using Gene Ontology and KEGG pathway analysis. For discriminating the proteome variation among samples, multivariate statistical analysis (PCA, PLS-DA) was performed by comparing the protein ratio differences. Further, performing pathway analysis on diatom proteomes, we here demonstrated downregulation of photosynthesis, carbon metabolism, and ribosome biogenesis in the cellular process that leads to decrease the oxidoreductase activity and affects the cell cycle of the diatom. Using PLS-DA VIP score plot analysis, we identified 15 protein biomarkers for discriminating studied samples. Of these, five proteins or gene (rbcL, PRK, atpB, DNA-binding, and signal transduction) identified as key biomarkers, induced by temperature and silicate stress in diatom metabolism. Our results show that proteomic finger-printing of S. dohrnii with different environmental conditions adds biological information that strengthens marine phytoplankton proteome analysis.
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Affiliation(s)
| | - Satheesh Kumar Palanisamy
- Department of Zoology, School of Natural Science, Ryan Institute, National University of Ireland, Galway, Ireland
| | - Guicheng Zhang
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin, China.,Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin, China
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences, Wuhan, China
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11
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Zhang M, Xing Y, Wang F, Mi T, Zhen Y. Responses of triacylglycerol synthesis in Skeletonema marinoi to nitrogen and phosphate starvations. JOURNAL OF PHYCOLOGY 2020; 56:1505-1520. [PMID: 32602937 DOI: 10.1111/jpy.13044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
Skeletonema marinoi is one of the most widespread marine planktonic diatoms in temperate coastal regions and sometimes can form massive blooms. Yet, the molecular mechanisms of triacylglycerol (TAG) synthesis in nutrient-deficient conditions for this species are still unknown. This study aimed to investigate how the TAG biosynthetic pathway of S. marinoi reacts to the culture age and nitrogen (N) or phosphorus (P) deficiency at molecular levels. Meanwhile, we also described the physiological and biochemical changes of S. marinoi in response to N or P starvation over time. To obtain reliable qRT-PCR data, six putative reference genes were identified for assessing expression stability using geNorm and BestKeeper software, and Actin exhibited the most stable expression across 45 tested S. marinoi samples. We found that the expression of TAG biosynthesis-related genes and ACCase enzyme activity varied in response to the different nutrient conditions and culture age. Taken together, we speculated that the capacity of TAG biosynthesis in S. marinoi is induced by N or P stress, and increases with culture age. Furthermore, TAG biosynthesis appears to respond more strongly to P deficiency than to N deficiency. Our study provides important insights into how diatoms regulate the TAG biosynthetic pathway when stressed by nutrient limitation. Besides, the data obtained from this study also provide useful clues for further exploring genes that can be used for metabolic engineering to enhance lipid production.
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Affiliation(s)
- Mei Zhang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
| | - Yongze Xing
- Fourth Institute of Oceanography, Ministry of Natural Resources, Beihai, 536002, China
| | - Fuwen Wang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
| | - Tiezhu Mi
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
| | - Yu Zhen
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266237, China
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China
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12
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Tagliabue A, Barrier N, Du Pontavice H, Kwiatkowski L, Aumont O, Bopp L, Cheung WWL, Gascuel D, Maury O. An iron cycle cascade governs the response of equatorial Pacific ecosystems to climate change. GLOBAL CHANGE BIOLOGY 2020; 26:6168-6179. [PMID: 32970390 DOI: 10.1111/gcb.15316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/07/2020] [Accepted: 08/09/2020] [Indexed: 05/24/2023]
Abstract
Earth System Models project that global climate change will reduce ocean net primary production (NPP), upper trophic level biota biomass and potential fisheries catches in the future, especially in the eastern equatorial Pacific. However, projections from Earth System Models are undermined by poorly constrained assumptions regarding the biological cycling of iron, which is the main limiting resource for NPP over large parts of the ocean. In this study, we show that the climate change trends in NPP and the biomass of upper trophic levels are strongly affected by modifying assumptions associated with phytoplankton iron uptake. Using a suite of model experiments, we find 21st century climate change impacts on regional NPP range from -12.3% to +2.4% under a high emissions climate change scenario. This wide range arises from variations in the efficiency of iron retention in the upper ocean in the eastern equatorial Pacific across different scenarios of biological iron uptake, which affect the strength of regional iron limitation. Those scenarios where nitrogen limitation replaced iron limitation showed the largest projected NPP declines, while those where iron limitation was more resilient displayed little future change. All model scenarios have similar skill in reproducing past inter-annual variations in regional ocean NPP, largely due to limited change in the historical period. Ultimately, projections of end of century upper trophic level biomass change are altered by 50%-80% across all plausible scenarios. Overall, we find that uncertainties in the biological iron cycle cascade through open ocean pelagic ecosystems, from plankton to fish, affecting their evolution under climate change. This highlights additional challenges to developing effective conservation and fisheries management policies under climate change.
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Affiliation(s)
| | - Nicolas Barrier
- MARBEC (IRD, Univ. Montpellier, CNRS, Ifremer), Sète, France
| | - Hubert Du Pontavice
- ESE, Ecology and Ecosystem Health, Institut Agro, Rennes, France
- Nippon Foundation-Nereus Program, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
| | | | - Olivier Aumont
- LOCEAN, Sorbonne Université-CNRS-IRD-MNHN, Paris, France
| | | | - William W L Cheung
- Nippon Foundation-Nereus Program, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
| | - Didier Gascuel
- ESE, Ecology and Ecosystem Health, Institut Agro, Rennes, France
| | - Olivier Maury
- MARBEC (IRD, Univ. Montpellier, CNRS, Ifremer), Sète, France
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13
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The Importance of Protein Phosphorylation for Signaling and Metabolism in Response to Diel Light Cycling and Nutrient Availability in a Marine Diatom. BIOLOGY 2020; 9:biology9070155. [PMID: 32640597 PMCID: PMC7408324 DOI: 10.3390/biology9070155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 01/23/2023]
Abstract
Diatoms are major contributors to global primary production and their populations in the modern oceans are affected by availability of iron, nitrogen, phosphate, silica, and other trace metals, vitamins, and infochemicals. However, little is known about the role of phosphorylation in diatoms and its role in regulation and signaling. We report a total of 2759 phosphorylation sites on 1502 proteins detected in Phaeodactylum tricornutum. Conditionally phosphorylated peptides were detected at low iron (n = 108), during the diel cycle (n = 149), and due to nitrogen availability (n = 137). Through a multi-omic comparison of transcript, protein, phosphorylation, and protein homology, we identify numerous proteins and key cellular processes that are likely under control of phospho-regulation. We show that phosphorylation regulates: (1) carbon retrenchment and reallocation during growth under low iron, (2) carbon flux towards lipid biosynthesis after the lights turn on, (3) coordination of transcription and translation over the diel cycle and (4) in response to nitrogen depletion. We also uncover phosphorylation sites for proteins that play major roles in diatom Fe sensing and utilization, including flavodoxin and phytotransferrin (ISIP2A), as well as identify phospho-regulated stress proteins and kinases. These findings provide much needed insight into the roles of protein phosphorylation in diel cycling and nutrient sensing in diatoms.
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14
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Rizkallah MR, Frickenhaus S, Trimborn S, Harms L, Moustafa A, Benes V, Gäbler-Schwarz S, Beszteri S. Deciphering Patterns of Adaptation and Acclimation in the Transcriptome of Phaeocystis antarctica to Changing Iron Conditions 1. JOURNAL OF PHYCOLOGY 2020; 56:747-760. [PMID: 32068264 DOI: 10.1111/jpy.12979] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
The haptophyte Phaeocystis antarctica is endemic to the Southern Ocean, where iron supply is sporadic and its availability limits primary production. In iron fertilization experiments, P. antarctica showed a prompt and steady increase in cell abundance compared to heavily silicified diatoms along with enhanced colony formation. Here we utilized a transcriptomic approach to investigate molecular responses to alleviation of iron limitation in P. antarctica. We analyzed the transcriptomic response before and after (14 h, 24 h and 72 h) iron addition to a low-iron acclimated culture. After iron addition, we observed indicators of a quick reorganization of cellular energetics, from carbohydrate catabolism and mitochondrial energy production to anabolism. In addition to typical substitution responses from an iron-economic toward an iron-sufficient state for flavodoxin (ferredoxin) and plastocyanin (cytochrome c6 ), we found other genes utilizing the same strategy involved in nitrogen assimilation and fatty acid desaturation. Our results shed light on a number of adaptive mechanisms that P. antarctica uses under low iron, including the utilization of a Cu-dependent ferric reductase system and indication of mixotrophic growth. The gene expression patterns underpin P. antarctica as a quick responder to iron addition.
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Affiliation(s)
| | - Stephan Frickenhaus
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- Centre for Industrial Mathematics, University of Bremen, Bibliothekstrasse 1, 28359 Postfach 330440, 28334, Bremen, Germany
| | - Scarlett Trimborn
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- Department of Marine Botany, University of Bremen, Bibliothekstrasse 1, 28359 Postfach 330440, 28334, Bremen, Germany
| | - Lars Harms
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Herrstrasse 231, 26129, Oldenburg, Germany
| | - Ahmed Moustafa
- Department of Biology, American University in Cairo, P.O. Box 74, 11835, Cairo, Egypt
| | - Vladimir Benes
- European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Steffi Gäbler-Schwarz
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Sara Beszteri
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
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15
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Kong L, Price NM. Identification of copper-regulated proteins in an oceanic diatom,Thalassiosira oceanica1005. Metallomics 2020; 12:1106-1117. [DOI: 10.1039/d0mt00033g] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plastocyanin-dependent diatoms adjust cellular metabolism to cope with chronic Cu deficiency.
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Affiliation(s)
- Liangliang Kong
- Department of Biology
- McGill University
- Montréal
- Canada
- College of Marine Life Sciences
| | - Neil M. Price
- Department of Biology
- McGill University
- Montréal
- Canada
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16
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Thangaraj S, Giordano M, Sun J. Comparative Proteomic Analysis Reveals New Insights Into the Common and Specific Metabolic Regulation of the Diatom Skeletonema dohrnii to the Silicate and Temperature Availability. FRONTIERS IN PLANT SCIENCE 2020; 11:578915. [PMID: 33224167 PMCID: PMC7674209 DOI: 10.3389/fpls.2020.578915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/28/2020] [Indexed: 05/12/2023]
Abstract
Silicate (Si) and temperature are essential drivers for diatom growth and development in the ocean. Response of diatoms to these particular stress has been investigated; however, their common and specific responses to regulate intracellular development and growth are not known. Here, we investigated the combination of physiological characteristics and comparative proteomics of the diatom Skeletonema dohrnii grown in silicate- and temperature-limited conditions. Results show that cell carbon and lipid quotas were higher at lower-temperature cells, whereas cellular phosphate was higher in cells grown with lower Si. In silicate-limited cells, nitrate transporters were downregulated and resulted in lower nitrate assimilation, whereas the phosphate transporters and its assimilation were reduced in lower-temperature conditions. In photosynthesis, lower silicate caused impact in the linear electron flow and NADPH production, whereas cycling electron transport and ATP production were affected by the lower temperature. Concerning cell cycle, imbalances in the translation process were observed in lower-silicate cells, whereas impact in the transcription mechanism was observed in lower-temperature cells. However, proteins associated with carbon fixation and photorespiration were downregulated in both stress conditions, while the carbohydrate and lipid synthesis proteins were upregulated. Our results showed new insights into the common and specific responses on the proteome and physiology of S. dohrnii to silicate and temperature limitation, providing particular nutrient (Si)- and temperature-dependent mechanisms in diatoms.
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Affiliation(s)
- Satheeswaran Thangaraj
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan, China
| | - Mario Giordano
- Dipartimento di Scienze della Vita e dell’Ambiente, Università Politecnica delle Marche, Ancona, Italy
| | - Jun Sun
- College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan, China
- *Correspondence: Jun Sun,
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17
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Krayushkina D, Timmins-Schiffman E, Faux J, May DH, Riffle M, Harvey HR, Nunn BL. Growth phase proteomics of the heterotrophic marine bacterium Ruegeria pomeroyi. Sci Data 2019; 6:303. [PMID: 31796751 PMCID: PMC6890736 DOI: 10.1038/s41597-019-0308-y] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/07/2019] [Indexed: 11/14/2022] Open
Abstract
The heterotrophic marine bacterium, Ruegeria pomeroyi, was experimentally cultured under environmentally realistic carbon conditions and with a tracer-level addition of 13C-labeled leucine to track bacterial protein biosynthesis through growth phases. A combination of methods allowed observation of real-time bacterial protein production to understand metabolic priorities through the different growth phases. Over 2000 proteins were identified in each experimental culture from exponential and stationary growth phases. Within two hours of the 13C-labeled leucine addition, R. pomeroyi significantly assimilated the newly encountered substrate into new proteins. This dataset provides a fundamental baseline for understanding growth phase differences in molecular physiology of a cosmopolitan marine bacterium.
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Affiliation(s)
- Dasha Krayushkina
- University of Washington, Department of Psychiatry and Behavioral Sciences, Seattle, WA, 98195, USA
| | | | - Jessica Faux
- Old Dominion University, Department of Ocean, Earth & Atmospheric Sciences, Norfolk, VA, 23529, USA
| | - Damon H May
- University of Washington, Department of Genome Sciences, Seattle, WA, 98195, USA
| | - Michael Riffle
- University of Washington, Department of Biochemistry, Seattle, WA, 98195, USA
| | - H Rodger Harvey
- Old Dominion University, Department of Ocean, Earth & Atmospheric Sciences, Norfolk, VA, 23529, USA
| | - Brook L Nunn
- University of Washington, Department of Genome Sciences, Seattle, WA, 98195, USA.
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18
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Goldman JAL, Schatz MJ, Berthiaume CT, Coesel SN, Orellana MV, Armbrust EV. Fe limitation decreases transcriptional regulation over the diel cycle in the model diatom Thalassiosira pseudonana. PLoS One 2019; 14:e0222325. [PMID: 31509589 PMCID: PMC6738920 DOI: 10.1371/journal.pone.0222325] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 08/27/2019] [Indexed: 01/02/2023] Open
Abstract
Iron (Fe) is an important growth factor for diatoms and its availability is further restricted by changes in the carbonate chemistry of seawater. We investigated the physiological attributes and transcriptional profiles of the diatom Thalassiosira pseudonana grown on a day: night cycle under different CO2/pH and iron concentrations, that in combination generated available iron (Fe') concentrations of 1160, 233, 58 and 12 pM. We found the light-dark conditions to be the main driver of transcriptional patterns, followed by Fe' concentration and CO2 availability, respectively. At the highest Fe' (1160 pM), 55% of the transcribed genes were differentially expressed between day and night, whereas at the lowest Fe' (12 pM), only 28% of the transcribed genes displayed comparable patterns. While Fe limitation disrupts the diel expression patterns for genes in most central metabolism pathways, the diel expression of light- signaling molecules and glycolytic genes was relatively robust in response to reduced Fe'. Moreover, we identified a non-canonical splicing of transcripts encoding triose-phosphate isomerase, a key-enzyme of glycolysis, generating transcript isoforms that would encode proteins with and without an active site. Transcripts that encoded an active enzyme maintained a diel expression at low Fe', while transcripts that encoded the non-active enzyme lost the diel expression. This work illustrates the interplay between nutrient limitation and transcriptional regulation over the diel cycle. Considering that future ocean conditions will reduce the availability of Fe in many parts of the oceans, our work identifies some of the regulatory mechanisms that may shape future ecological communities.
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Affiliation(s)
- Johanna A. L. Goldman
- School of Oceanography, University of Washington, Seattle, Washington, United States of America
| | - Megan J. Schatz
- School of Oceanography, University of Washington, Seattle, Washington, United States of America
| | - Chris T. Berthiaume
- School of Oceanography, University of Washington, Seattle, Washington, United States of America
| | - Sacha N. Coesel
- School of Oceanography, University of Washington, Seattle, Washington, United States of America
| | - Mónica V. Orellana
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, Washington, United States of America
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - E. Virginia Armbrust
- School of Oceanography, University of Washington, Seattle, Washington, United States of America
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19
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Louropoulou E, Gledhill M, Browning TJ, Desai DK, Barraqueta JLM, Tonnard M, Sarthou G, Planquette H, Bowie AR, Schmitz RA, LaRoche J, Achterberg EP. Regulation of the Phytoplankton Heme b Iron Pool During the North Atlantic Spring Bloom. Front Microbiol 2019; 10:1566. [PMID: 31354666 PMCID: PMC6637849 DOI: 10.3389/fmicb.2019.01566] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/24/2019] [Indexed: 11/13/2022] Open
Abstract
Heme b is an iron-containing co-factor in hemoproteins. Heme b concentrations are low (<1 pmol L-1) in iron limited phytoplankton in cultures and in the field. Here, we determined heme b in marine particulate material (>0.7 μm) from the North Atlantic Ocean (GEOVIDE cruise - GEOTRACES section GA01), which spanned several biogeochemical regimes. We examined the relationship between heme b abundance and the microbial community composition, and its utility for mapping iron limited phytoplankton. Heme b concentrations ranged from 0.16 to 5.1 pmol L-1 (median = 2.0 pmol L-1, n = 62) in the surface mixed layer (SML) along the cruise track, driven mainly by variability in biomass. However, in the Irminger Basin, the lowest heme b levels (SML: median = 0.53 pmol L-1, n = 12) were observed, whilst the biomass was highest (particulate organic carbon, median = 14.2 μmol L-1, n = 25; chlorophyll a: median = 2.0 nmol L-1, n = 23) pointing to regulatory mechanisms of the heme b pool for growth conservation. Dissolved iron (DFe) was not depleted (SML: median = 0.38 nmol L-1, n = 11) in the Irminger Basin, but large diatoms (Rhizosolenia sp.) dominated. Hence, heme b depletion and regulation is likely to occur during bloom progression when phytoplankton class-dependent absolute iron requirements exceed the available ambient concentration of DFe. Furthermore, high heme b concentrations found in the Iceland Basin and Labrador Sea (median = 3.4 pmol L-1, n = 20), despite having similar DFe concentrations to the Irminger Basin, were attributed to an earlier growth phase of the extant phytoplankton populations. Thus, heme b provides a snapshot of the cellular activity in situ and could both be used as indicator of iron limitation and contribute to understanding phytoplankton adaptation mechanisms to changing iron supplies.
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Affiliation(s)
- Evangelia Louropoulou
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.,Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Martha Gledhill
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | | | - Dhwani K Desai
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Jan-Lukas Menzel Barraqueta
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.,Department of Earth Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Manon Tonnard
- UMR 6539/LEMAR/IUEM, CNRS, UBO, IRD, Ifremer, Brest, France.,Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, TAS, Australia.,Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | | | | | - Andrew R Bowie
- Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, TAS, Australia.,Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Ruth A Schmitz
- Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Julie LaRoche
- Department of Biology, Dalhousie University, Halifax, NS, Canada
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20
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Thangaraj S, Shang X, Sun J, Liu H. Quantitative Proteomic Analysis Reveals Novel Insights into Intracellular Silicate Stress-Responsive Mechanisms in the Diatom Skeletonema dohrnii. Int J Mol Sci 2019; 20:E2540. [PMID: 31126124 PMCID: PMC6566588 DOI: 10.3390/ijms20102540] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/19/2019] [Accepted: 05/20/2019] [Indexed: 01/04/2023] Open
Abstract
Diatoms are a successful group of marine phytoplankton that often thrives under adverse environmental stress conditions. Members of the Skeletonema genus are ecologically important which may subsist during silicate stress and form a dense bloom following higher silicate concentration. However, our understanding of diatoms' underlying molecular mechanism involved in these intracellular silicate stress-responses are limited. Here an iTRAQ-based proteomic method was coupled with multiple physiological techniques to explore distinct cellular responses associated with oxidative stress in the diatom Skeletonema dohrnii to the silicate limitation. In total, 1768 proteins were detected; 594 proteins were identified as differentially expressed (greater than a two-fold change; p < 0.05). In Si-limited cells, downregulated proteins were mainly related to photosynthesis metabolism, light-harvesting complex, and oxidative phosphorylation, corresponding to inducing oxidative stress, and ROS accumulation. None of these responses were identified in Si-limited cells; in comparing with other literature, Si-stress cells showed that ATP-limited diatoms are unable to rely on photosynthesis, which will break down and reshuffle carbon metabolism to compensate for photosynthetic carbon fixation losses. Our findings have a good correlation with earlier reports and provides a new molecular level insight into the systematic intracellular responses employed by diatoms in response to silicate stress in the marine environment.
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Affiliation(s)
- Satheeswaran Thangaraj
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Faculty of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
| | - Xiaomei Shang
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
| | - Jun Sun
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
| | - Haijiao Liu
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Research Center for Indian Ocean Ecosystem, Tianjin University of Science and Technology, No 29, 13th Avenue, TEDA, Tianjin 300457, China.
- Institute of Marine Science and Technology, Shandong University, No 27, Shanda Nan Road, Jinan 250110, China.
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21
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Saito MA, Bertrand EM, Duffy ME, Gaylord DA, Held NA, Hervey WJ, Hettich RL, Jagtap PD, Janech MG, Kinkade DB, Leary DH, McIlvin MR, Moore EK, Morris RM, Neely BA, Nunn BL, Saunders JK, Shepherd AI, Symmonds NI, Walsh DA. Progress and Challenges in Ocean Metaproteomics and Proposed Best Practices for Data Sharing. J Proteome Res 2019; 18:1461-1476. [PMID: 30702898 DOI: 10.1021/acs.jproteome.8b00761] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ocean metaproteomics is an emerging field enabling discoveries about marine microbial communities and their impact on global biogeochemical processes. Recent ocean metaproteomic studies have provided insight into microbial nutrient transport, colimitation of carbon fixation, the metabolism of microbial biofilms, and dynamics of carbon flux in marine ecosystems. Future methodological developments could provide new capabilities such as characterizing long-term ecosystem changes, biogeochemical reaction rates, and in situ stoichiometries. Yet challenges remain for ocean metaproteomics due to the great biological diversity that produces highly complex mass spectra, as well as the difficulty in obtaining and working with environmental samples. This review summarizes the progress and challenges facing ocean metaproteomic scientists and proposes best practices for data sharing of ocean metaproteomic data sets, including the data types and metadata needed to enable intercomparisons of protein distributions and annotations that could foster global ocean metaproteomic capabilities.
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Affiliation(s)
- Mak A Saito
- Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
| | - Erin M Bertrand
- Department of Biology , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Megan E Duffy
- School of Oceanography , University of Washington , Seattle , Washington 98195-7940 , United States
| | - David A Gaylord
- Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
| | - Noelle A Held
- Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
| | | | - Robert L Hettich
- Oak Ridge National Laboratory and Microbiology Department , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Pratik D Jagtap
- Department of Biochemistry, Molecular Biology and Biophysics , University of Minnesota , Saint Paul , Minnesota 55108 , United States
| | - Michael G Janech
- College of Charleston , Charleston , South Carolina 29424 , United States
| | - Danie B Kinkade
- Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
| | - Dagmar H Leary
- U.S. Naval Research Laboratory , Washington , D.C. 20375 , United States
| | - Matthew R McIlvin
- Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
| | - Eli K Moore
- Department of Environmental Science , Rowan University , Glassboro , New Jersey 08028 , United States
| | - Robert M Morris
- School of Oceanography , University of Washington , Seattle , Washington 98195-7940 , United States
| | - Benjamin A Neely
- National Institute of Standards and Technology , Charleston , South Carolina 29412 , United States
| | - Brook L Nunn
- Department of Genome Sciences , University of Washington , Seattle , Washington 98195 , United States
| | - Jaclyn K Saunders
- Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States.,School of Oceanography , University of Washington , Seattle , Washington 98195-7940 , United States
| | - Adam I Shepherd
- Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
| | - Nicholas I Symmonds
- Woods Hole Oceanographic Institution , Woods Hole , Massachusetts 02543 , United States
| | - David A Walsh
- Department of Biology , Concordia University , Montreal , Quebec H4B 1R6 , Canada
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22
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Proteome evolution under non-substitutable resource limitation. Nat Commun 2018; 9:4650. [PMID: 30405128 PMCID: PMC6220234 DOI: 10.1038/s41467-018-07106-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 10/10/2018] [Indexed: 12/12/2022] Open
Abstract
Resource limitation is a major driver of the ecological and evolutionary dynamics of organisms. Short-term responses to resource limitation include plastic changes in molecular phenotypes including protein expression. Yet little is known about the evolution of the molecular phenotype under longer-term resource limitation. Here, we combine experimental evolution of the green alga Chlamydomonas reinhardtii under multiple different non-substitutable resource limitation regimes with proteomic measurements to investigate evolutionary adaptation of the molecular phenotype. We demonstrate convergent proteomic evolution of core metabolic functions, including the Calvin-Benson cycle and gluconeogenesis, across different resource limitation environments. We do not observe proteomic changes consistent with optimized uptake of particular limiting resources. Instead, we report that adaptation proceeds in similar directions under different types of non-substitutable resource limitation. This largely convergent evolution of the expression of core metabolic proteins is associated with an improvement in the resource assimilation efficiency of nitrogen and phosphorus into biomass. Organisms could respond to essential resource limitation by increasing metabolic efficiency or resource acquisition ability. Here, the authors experimentally evolve green algae under different resource limitations and show convergent evolution of core metabolism rather than resource specialization.
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23
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Cohen NR, Gong W, Moran DM, McIlvin MR, Saito MA, Marchetti A. Transcriptomic and proteomic responses of the oceanic diatom
Pseudo‐nitzschia granii
to iron limitation. Environ Microbiol 2018; 20:3109-3126. [DOI: 10.1111/1462-2920.14386] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 08/09/2018] [Accepted: 08/12/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Natalie R Cohen
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill NC 27514 USA
- Marine Chemistry and Geochemistry Department Woods Hole Oceanographic Institution Woods Hole MA 02543 USA
| | - Weida Gong
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill NC 27514 USA
| | - Dawn M. Moran
- Marine Chemistry and Geochemistry Department Woods Hole Oceanographic Institution Woods Hole MA 02543 USA
| | - Matthew R. McIlvin
- Marine Chemistry and Geochemistry Department Woods Hole Oceanographic Institution Woods Hole MA 02543 USA
| | - Mak A. Saito
- Marine Chemistry and Geochemistry Department Woods Hole Oceanographic Institution Woods Hole MA 02543 USA
| | - Adrian Marchetti
- Department of Marine Sciences University of North Carolina at Chapel Hill Chapel Hill NC 27514 USA
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24
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Timmins-Schiffman E, Mikan MP, Ting YS, Harvey HR, Nunn BL. MS analysis of a dilution series of bacteria:phytoplankton to improve detection of low abundance bacterial peptides. Sci Rep 2018; 8:9276. [PMID: 29915279 PMCID: PMC6006377 DOI: 10.1038/s41598-018-27650-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 06/06/2018] [Indexed: 11/17/2022] Open
Abstract
Assigning links between microbial activity and biogeochemical cycles in the ocean is a primary objective for ecologists and oceanographers. Bacteria represent a small ecosystem component by mass, but act as the nexus for both nutrient transformation and organic matter recycling. There are limited methods to explore the full suite of active bacterial proteins largely responsible for degradation. Mass spectrometry (MS)-based proteomics now has the potential to document bacterial physiology within these complex systems. Global proteome profiling using MS, known as data dependent acquisition (DDA), is limited by the stochastic nature of ion selection, decreasing the detection of low abundance peptides. The suitability of MS-based proteomics methods in revealing bacterial signatures outnumbered by phytoplankton proteins was explored using a dilution series of pure bacteria (Ruegeria pomeroyi) and diatoms (Thalassiosira pseudonana). Two common acquisition strategies were utilized: DDA and selected reaction monitoring (SRM). SRM improved detection of bacterial peptides at low bacterial cellular abundance that were undetectable with DDA from a wide range of physiological processes (e.g. amino acid synthesis, lipid metabolism, and transport). We demonstrate the benefits and drawbacks of two different proteomic approaches for investigating species-specific physiological processes across relative abundances of bacteria that vary by orders of magnitude.
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Affiliation(s)
| | - Molly P Mikan
- Old Dominion University, Department of Ocean, Earth, and Atmospheric Sciences, Norfolk, VA, 23529, USA
| | - Ying Sonia Ting
- University of Washington, Department of Genome Sciences, Seattle, WA, 98195, USA
- Neon Therapeutics, Boston, MA, 02139, USA
| | - H Rodger Harvey
- Old Dominion University, Department of Ocean, Earth, and Atmospheric Sciences, Norfolk, VA, 23529, USA
| | - Brook L Nunn
- University of Washington, Department of Genome Sciences, Seattle, WA, 98195, USA.
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25
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Wagner H, Jakob T, Fanesi A, Wilhelm C. Towards an understanding of the molecular regulation of carbon allocation in diatoms: the interaction of energy and carbon allocation. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0410. [PMID: 28717020 DOI: 10.1098/rstb.2016.0410] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2017] [Indexed: 11/12/2022] Open
Abstract
In microalgae, the photosynthesis-driven CO2 assimilation delivers cell building blocks that are used in different biosynthetic pathways. Little is known about how the cell regulates the subsequent carbon allocation to, for example, cell growth or for storage. However, knowledge about these regulatory mechanisms is of high biotechnological and ecological importance. In diatoms, the situation becomes even more complex because, as a consequence of their secondary endosymbiotic origin, the compartmentation of the pathways for the primary metabolic routes is different from green algae. Therefore, the mechanisms to manipulate the carbon allocation pattern cannot be adopted from the green lineage. This review describes the general pathways of cellular energy distribution from light absorption towards the final allocation of carbon into macromolecules and summarizes the current knowledge of diatom-specific allocation patterns. We further describe the (limited) knowledge of regulatory mechanisms of carbon partitioning between lipids, carbohydrates and proteins in diatoms. We present solutions to overcome the problems that hinder the identification of regulatory elements of carbon metabolism.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.
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Affiliation(s)
- Heiko Wagner
- Department of Plant Physiology, Leipzig University, Institute of Biology, Johannisallee 21-23, 04103 Leipzig, Germany
| | - Torsten Jakob
- Department of Plant Physiology, Leipzig University, Institute of Biology, Johannisallee 21-23, 04103 Leipzig, Germany
| | - Andrea Fanesi
- Department of Plant Physiology, Leipzig University, Institute of Biology, Johannisallee 21-23, 04103 Leipzig, Germany
| | - Christian Wilhelm
- Department of Plant Physiology, Leipzig University, Institute of Biology, Johannisallee 21-23, 04103 Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
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26
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Burge DRL, Edlund MB, Frisch D. Paleolimnology and resurrection ecology: The future of reconstructing the past. Evol Appl 2018; 11:42-59. [PMID: 29302271 PMCID: PMC5748527 DOI: 10.1111/eva.12556] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/08/2017] [Indexed: 12/21/2022] Open
Abstract
Paleolimnologists have utilized lake sediment records to understand historical lake and landscape development, timing and magnitude of environmental change at lake, watershed, regional and global scales, and as historical datasets to target watershed and lake management. Resurrection ecologists have long recognized lake sediments as sources of viable propagules ("seed or egg banks") with which to explore questions of community ecology, ecological response, and evolutionary ecology. Most researchers consider Daphnia as the primary model organism in these efforts, but many other aquatic biota, from viruses to macrophytes, similarly produce viable propagules that are incorporated in the sediment record but have been underutilized in resurrection ecology. The common goals shared by these two disciplines have led to mutualistic and synergistic collaborations-a development that must be encouraged to expand. We give an overview of the achievements of paleolimnology and the reconstruction of environmental history of lakes, review the untapped diversity of aquatic organisms that produce dormant propagules, compare Daphnia as a model of resurrection ecology with other organisms amenable to resurrection studies, especially diatoms, and consider new research directions that represent the nexus of these two fields.
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Affiliation(s)
- David R. L. Burge
- St. Croix Watershed Research StationScience Museum of MinnesotaMarine on St. CroixMNUSA
- Water Resources Science Graduate ProgramUniversity of MinnesotaSt. PaulMNUSA
| | - Mark B. Edlund
- St. Croix Watershed Research StationScience Museum of MinnesotaMarine on St. CroixMNUSA
| | - Dagmar Frisch
- School of BiosciencesUniversity of BirminghamBirminghamUK
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27
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Lin Q, Liang JR, Huang QQ, Luo CS, Anderson DM, Bowler C, Chen CP, Li XS, Gao YH. Differential cellular responses associated with oxidative stress and cell fate decision under nitrate and phosphate limitations in Thalassiosira pseudonana: Comparative proteomics. PLoS One 2017; 12:e0184849. [PMID: 28910417 PMCID: PMC5599023 DOI: 10.1371/journal.pone.0184849] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 08/31/2017] [Indexed: 01/09/2023] Open
Abstract
Diatoms are important components of marine ecosystems and contribute greatly to the world's primary production. Despite their important roles in ecosystems, the molecular basis of how diatoms cope with oxidative stress caused by nutrient fluctuations remains largely unknown. Here, an isobaric tags for relative and absolute quantitation (iTRAQ) proteomic method was coupled with a series of physiological and biochemical techniques to explore oxidative stress- and cell fate decision-related cellular and metabolic responses of the diatom Thalassiosira pseudonana to nitrate (N) and inorganic phosphate (P) stresses. A total of 1151 proteins were detected; 122 and 56 were significantly differentially expressed from control under N- and P-limited conditions, respectively. In N-limited cells, responsive proteins were related to reactive oxygen species (ROS) accumulation, oxidative stress responses and cell death, corresponding to a significant decrease in photosynthetic efficiency, marked intracellular ROS accumulation, and caspase-mediated programmed cell death activation. None of these responses were identified in P-limited cells; however, a significant up-regulation of alkaline phosphatase proteins was observed, which could be the major contributor for P-limited cells to cope with ambient P deficiency. These findings demonstrate that fundamentally different metabolic responses and cellular regulations are employed by the diatom in response to different nutrient stresses and to keep the cells viable.
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Affiliation(s)
- Qun Lin
- School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
- School of Life Sciences, Xiamen University, Xiamen, China
| | - Jun-Rong Liang
- School of Life Sciences, Xiamen University, Xiamen, China
- Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, Xiamen, China
- * E-mail:
| | | | - Chun-Shan Luo
- School of Life Sciences, Xiamen University, Xiamen, China
| | - Donald M. Anderson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Chris Bowler
- Ecology and Evolutionary Biology Section, CNRS UMR8197 INSERM U1024, Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, 46 rue d’Ulm, Paris, France
| | - Chang-Ping Chen
- School of Life Sciences, Xiamen University, Xiamen, China
- Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, Xiamen, China
| | - Xue-Song Li
- School of Life Sciences, Xiamen University, Xiamen, China
| | - Ya-Hui Gao
- School of Life Sciences, Xiamen University, Xiamen, China
- Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, Xiamen, China
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28
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Bernal-Bayard P, Puerto-Galán L, Yruela I, García-Rubio I, Castell C, Ortega JM, Alonso PJ, Roncel M, Martínez JI, Hervás M, Navarro JA. The photosynthetic cytochrome c 550 from the diatom Phaeodactylum tricornutum. PHOTOSYNTHESIS RESEARCH 2017; 133:273-287. [PMID: 28032235 DOI: 10.1007/s11120-016-0327-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 12/14/2016] [Indexed: 06/06/2023]
Abstract
The photosynthetic cytochrome c 550 from the marine diatom Phaeodactylum tricornutum has been purified and characterized. Cytochrome c 550 is mostly obtained from the soluble cell extract in relatively large amounts. In addition, the protein appeared to be truncated in the last hydrophobic residues of the C-terminus, both in the soluble cytochrome c 550 and in the protein extracted from the membrane fraction, as deduced by mass spectrometry analysis and the comparison with the gene sequence. Interestingly, it has been described that the C-terminus of cytochrome c 550 forms a hydrophobic finger involved in the interaction with photosystem II in cyanobacteria. Cytochrome c 550 was almost absent in solubilized photosystem II complex samples, in contrast with the PsbO and Psb31 extrinsic subunits, thus suggesting a lower affinity of cytochrome c 550 for the photosystem II complex. Under iron-limiting conditions the amount of cytochrome c 550 decreases up to about 45% as compared to iron-replete cells, pointing to an iron-regulated synthesis. Oxidized cytochrome c 550 has been characterized using continuous wave EPR and pulse techniques, including HYSCORE, and the obtained results have been interpreted in terms of the electrostatic charge distribution in the surroundings of the heme centre.
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Affiliation(s)
- Pilar Bernal-Bayard
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain
| | - Leonor Puerto-Galán
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain
| | | | - Inés García-Rubio
- Centro Universitario de la Defensa, Zaragoza, Spain
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Carmen Castell
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain
| | - José M Ortega
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain
| | - Pablo J Alonso
- Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza & CSIC, Zaragoza, Spain
| | - Mercedes Roncel
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain
| | - Jesús I Martínez
- Centro Universitario de la Defensa, Zaragoza, Spain
- Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza & CSIC, Zaragoza, Spain
| | - Manuel Hervás
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain
| | - José A Navarro
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain.
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29
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Intraspecific variability in Phaeocystis antarctica's response to iron and light stress. PLoS One 2017; 12:e0179751. [PMID: 28692685 PMCID: PMC5503234 DOI: 10.1371/journal.pone.0179751] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 06/02/2017] [Indexed: 12/13/2022] Open
Abstract
Phaeocystis antarctica is an abundant phytoplankton species in the Southern Ocean, where growth is frequently limited by iron and light. Being able to grow under low iron conditions is essential to the species’ success, but there have been hints that this ability differs among clones. Here, we compare the growth, cell size and chlorophyll a concentrations of four P. antarctica clones cultured under different iron and light conditions. Iron was provided either as unchelated iron (Fe′) or bound to the bacterial siderophore desferrioxamine B, representing, respectively, the most and least bioavailable forms of iron which phytoplankton encounter in the marine environment. The growth rate data demonstrate that the clones vary in their ability to grow using organically bound iron, and that this ability is not related to their ability to grow at low inorganic iron concentrations. These results are consistent at low and high light. Physiologically, only three of the four clones shrink or decrease the concentration of chlorophyll a in response to iron limitation, and only one clone decreases colony formation. Together, our data show that P. antarctica clones 1) respond to the same degree of iron limitation using different acclimation strategies, and 2) vary in their ability to grow under the same external iron and light conditions. This physiological diversity is surprisingly large for isolates of a single phytoplankton species.
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30
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Botebol H, Lelandais G, Six C, Lesuisse E, Meng A, Bittner L, Lecrom S, Sutak R, Lozano JC, Schatt P, Vergé V, Blain S, Bouget FY. Acclimation of a low iron adapted Ostreococcus strain to iron limitation through cell biomass lowering. Sci Rep 2017; 7:327. [PMID: 28336917 PMCID: PMC5428002 DOI: 10.1038/s41598-017-00216-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/14/2017] [Indexed: 11/17/2022] Open
Abstract
Iron is an essential micronutrient involved in many biological processes and is often limiting for primary production in large regions of the World Ocean. Metagenomic and physiological studies have identified clades or ecotypes of marine phytoplankton that are specialized in iron depleted ecological niches. Although less studied, eukaryotic picophytoplankton does contribute significantly to primary production and carbon transfer to higher trophic levels. In particular, metagenomic studies of the green picoalga Ostreococcus have revealed the occurrence of two main clades distributed along coast-offshore gradients, suggesting niche partitioning in different nutrient regimes. Here, we present a study of the response to iron limitation of four Ostreococcus strains isolated from contrasted environments. Whereas the strains isolated in nutrient-rich waters showed high iron requirements, the oceanic strains could cope with lower iron concentrations. The RCC802 strain, in particular, was able to maintain high growth rate at low iron levels. Together physiological and transcriptomic data indicate that the competitiveness of RCC802 under iron limitation is related to a lowering of iron needs though a reduction of the photosynthetic machinery and of protein content, rather than to cell size reduction. Our results overall suggest that iron is one of the factors driving the differentiation of physiologically specialized Ostreococcus strains in the ocean.
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Affiliation(s)
- Hugo Botebol
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France
| | - Gaelle Lelandais
- Université Paris Diderot (Paris 07), Centre National de la Recherche Scientifique, Institut Jacques Monod, F-75013, Paris, France
| | - Christophe Six
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique, UMR 7144, Adaptation et Diversité en Milieu Marin, Equipe Marine Phototrophic Prokaryotes, Station Biologique de Roscoff, 29680, Roscoff Cedex, France
| | - Emmanuel Lesuisse
- Université Paris Diderot (Paris 07), Centre National de la Recherche Scientifique, Institut Jacques Monod, F-75013, Paris, France
| | - Arnaud Meng
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut de Biologie Paris-Seine (IBPS), Evolution Paris Seine, F-75005, Paris, France
| | - Lucie Bittner
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut de Biologie Paris-Seine (IBPS), Evolution Paris Seine, F-75005, Paris, France
| | - Stéphane Lecrom
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut de Biologie Paris-Seine (IBPS), Evolution Paris Seine, F-75005, Paris, France
| | - Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University, 12844, Prague, Czech Republic
| | - Jean-Claude Lozano
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France
| | - Philippe Schatt
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France
| | - Valérie Vergé
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France
| | - Stéphane Blain
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
| | - François-Yves Bouget
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
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31
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Responses of the marine diatom Thalassiosira pseudonana to changes in CO 2 concentration: a proteomic approach. Sci Rep 2017; 7:42333. [PMID: 28181560 PMCID: PMC5299434 DOI: 10.1038/srep42333] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 01/10/2017] [Indexed: 12/18/2022] Open
Abstract
The concentration of CO2 in many aquatic systems is variable, often lower than the KM of the primary carboxylating enzyme Rubisco, and in order to photosynthesize efficiently, many algae operate a facultative CO2 concentrating mechanism (CCM). Here we measured the responses of a marine diatom, Thalassiosira pseudonana, to high and low concentrations of CO2 at the level of transcripts, proteins and enzyme activity. Low CO2 caused many metabolic pathways to be remodeled. Carbon acquisition enzymes, primarily carbonic anhydrase, stress, degradation and signaling proteins were more abundant while proteins associated with nitrogen metabolism, energy production and chaperones were less abundant. A protein with similarities to the Ca2+/ calmodulin dependent protein kinase II_association domain, having a chloroplast targeting sequence, was only present at low CO2. This protein might be a specific response to CO2 limitation since a previous study showed that other stresses caused its reduction. The protein sequence was found in other marine diatoms and may play an important role in their response to low CO2 concentration.
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32
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Smith SR, Gillard JTF, Kustka AB, McCrow JP, Badger JH, Zheng H, New AM, Dupont CL, Obata T, Fernie AR, Allen AE. Transcriptional Orchestration of the Global Cellular Response of a Model Pennate Diatom to Diel Light Cycling under Iron Limitation. PLoS Genet 2016; 12:e1006490. [PMID: 27973599 PMCID: PMC5156380 DOI: 10.1371/journal.pgen.1006490] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/16/2016] [Indexed: 11/23/2022] Open
Abstract
Environmental fluctuations affect distribution, growth and abundance of diatoms in nature, with iron (Fe) availability playing a central role. Studies on the response of diatoms to low Fe have either utilized continuous (24 hr) illumination or sampled a single time of day, missing any temporal dynamics. We profiled the physiology, metabolite composition, and global transcripts of the pennate diatom Phaeodactylum tricornutum during steady-state growth at low, intermediate, and high levels of dissolved Fe over light:dark cycles, to better understand fundamental aspects of genetic control of physiological acclimation to growth under Fe-limitation. We greatly expand the catalog of genes involved in the low Fe response, highlighting the importance of intracellular trafficking in Fe-limited diatoms. P. tricornutum exhibited transcriptomic hallmarks of slowed growth leading to prolonged periods of cell division/silica deposition, which could impact biogeochemical carbon sequestration in Fe-limited regions. Light harvesting and ribosome biogenesis transcripts were generally reduced under low Fe while transcript levels for genes putatively involved in the acquisition and recycling of Fe were increased. We also noted shifts in expression towards increased synthesis and catabolism of branched chain amino acids in P. tricornutum grown at low Fe whereas expression of genes involved in central core metabolism were relatively unaffected, indicating that essential cellular function is protected. Beyond the response of P. tricornutum to low Fe, we observed major coordinated shifts in transcript control of primary and intermediate metabolism over light:dark cycles which contribute to a new view of the significance of distinctive diatom pathways, such as mitochondrial glycolysis and the ornithine-urea cycle. This study provides new insight into transcriptional modulation of diatom physiology and metabolism across light:dark cycles in response to Fe availability, providing mechanistic understanding for the ability of diatoms to remain metabolically poised to respond quickly to Fe input and revealing strategies underlying their ecological success. Oceanic diatoms live in constantly fluctuating environments to which they must adapt in order to survive. During sunlit hours, photosynthesis occurs allowing diatoms to store energy used at night to sustain energy demands. Cellular and molecular mechanisms for regulation of phytoplankton growth are important to understand because of their environmental roles at the base of food webs and in regulating carbon flux out of the atmosphere. In ocean ecosystems, the availability of iron (Fe) commonly limits phytoplankton growth and diatoms typically outcompete other phytoplankton when Fe is added, indicating they have adaptations allowing them to both survive at low Fe and rapidly respond to Fe additions. These adaptations may be unique depending on isolation from coastal or oceanic locations. To identify adaptive strategies, we characterized the response of a model diatom, Phaeodactylum tricornutum, to limiting Fe conditions over day:night cycles using a combination of gene expression analyses, metabolite, and physiology measurements. Major coordinated shifts in metabolism and growth were documented over diel cycles, with peak expression of low Fe expressed genes in the dark phase. Diatoms respond to limiting Fe by increasing Fe acquisition, while decreasing growth rate through slowed cell cycle progression, reduced energy acquisition, and subtle metabolic remodeling.
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Affiliation(s)
- Sarah R. Smith
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, California, United States of America
- J. Craig Venter Institute, La Jolla, California, United States of America
| | - Jeroen T. F. Gillard
- J. Craig Venter Institute, La Jolla, California, United States of America
- Department of Biology, CSU Bakersfield, Bakersfield, California, United States of America
| | - Adam B. Kustka
- Department of Earth and Environmental Sciences, Rutgers University, Newark, New Jersey, United States of America
| | - John P. McCrow
- J. Craig Venter Institute, La Jolla, California, United States of America
| | - Jonathan H. Badger
- J. Craig Venter Institute, La Jolla, California, United States of America
| | - Hong Zheng
- J. Craig Venter Institute, La Jolla, California, United States of America
| | - Ashley M. New
- Department of Earth and Environmental Sciences, Rutgers University, Newark, New Jersey, United States of America
| | - Chris L. Dupont
- J. Craig Venter Institute, La Jolla, California, United States of America
| | - Toshihiro Obata
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam, Germany
| | - Alisdair R. Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Potsdam, Germany
| | - Andrew E. Allen
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, California, United States of America
- J. Craig Venter Institute, La Jolla, California, United States of America
- * E-mail: ,
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33
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Dong HP, Dong YL, Cui L, Balamurugan S, Gao J, Lu SH, Jiang T. High light stress triggers distinct proteomic responses in the marine diatom Thalassiosira pseudonana. BMC Genomics 2016; 17:994. [PMID: 27919227 PMCID: PMC5139114 DOI: 10.1186/s12864-016-3335-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 11/17/2016] [Indexed: 11/16/2022] Open
Abstract
Background Diatoms are able to acclimate to frequent and large light fluctuations in the surface ocean waters. However, the molecular mechanisms underlying these acclimation responses of diaotms remain elusive. Results In this study, we investigated the mechanism of high light protection in marine diatom Thalassiosira pseudonana using comparative proteomics in combination with biochemical analyses. Cells treated under high light (800 μmol photons m−2s−1) for 10 h were subjected to proteomic analysis. We observed that 143 proteins were differentially expressed under high light treatment. Light-harvesting complex proteins, ROS scavenging systems, photorespiration, lipid metabolism and some specific proteins might be involved in light protection and acclimation of diatoms. Non-photochemical quenching (NPQ) and relative electron transport rate could respond rapidly to varying light intensities. High-light treatment also resulted in increased diadinoxanthin + diatoxanthin content, decreased Fv/Fm, increased triacylglycerol and altered fatty acid composition. Under HL stress, levels of C14:0 and C16:0 increased while C20:5ω3 decreased. Conclusions We demonstrate that T. pseudonana has efficient photoprotective mechanisms to deal with HL stress. De novo synthesis of Ddx/Dtx and lipid accumulation contribute to utilization of the excess energy. Our data will provide new clues for in-depth study of photoprotective mechanisms in diatoms. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3335-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hong-Po Dong
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.,School of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Yue-Lei Dong
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
| | - Lei Cui
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
| | - Srinivasan Balamurugan
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
| | - Jian Gao
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
| | - Song-Hui Lu
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.
| | - Tao Jiang
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
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Caron DA, Alexander H, Allen AE, Archibald JM, Armbrust EV, Bachy C, Bell CJ, Bharti A, Dyhrman ST, Guida SM, Heidelberg KB, Kaye JZ, Metzner J, Smith SR, Worden AZ. Probing the evolution, ecology and physiology of marine protists using transcriptomics. Nat Rev Microbiol 2016; 15:6-20. [DOI: 10.1038/nrmicro.2016.160] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Longworth J, Wu D, Huete-Ortega M, Wright PC, Vaidyanathan S. Proteome response of Phaeodactylum tricornutum, during lipid accumulation induced by nitrogen depletion. ALGAL RES 2016; 18:213-224. [PMID: 27812494 PMCID: PMC5070409 DOI: 10.1016/j.algal.2016.06.015] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 05/08/2016] [Accepted: 06/14/2016] [Indexed: 11/26/2022]
Abstract
Nitrogen stress is a common strategy employed to stimulate lipid accumulation in microalgae, a biofuel feedstock of topical interest. Although widely investigated, the underlying mechanism of this strategy is still poorly understood. We examined the proteome response of lipid accumulation in the model diatom, Phaeodactylum tricornutum (CCAP 1055/1), at an earlier stage of exposure to selective nitrogen exclusion than previously investigated, and at a time point when changes would reflect lipid accumulation more than carbohydrate accumulation. In total 1043 proteins were confidently identified (≥ 2 unique peptides) with 645 significant (p < 0.05) changes observed, in the LC-MS/MS based iTRAQ investigation. Analysis of significant changes in KEGG pathways and individual proteins showed that under nitrogen starvation P. tricornutum reorganizes its proteome in favour of nitrogen scavenging and reduced lipid degradation whilst rearranging the central energy metabolism that deprioritizes photosynthetic pathways. By doing this, this species appears to increase nitrogen availability inside the cell and limit its use to the pathways where it is needed most. Compared to previously published proteomic analysis of nitrogen starvation in Chlamydomonas reinhardtii, central energy metabolism and photosynthesis appear to be affected more in the diatom, whilst the green algae appears to invest its energy in reorganizing respiration and the cellular organization pathways.
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36
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Grouneva I, Muth-Pawlak D, Battchikova N, Aro EM. Changes in Relative Thylakoid Protein Abundance Induced by Fluctuating Light in the Diatom Thalassiosira pseudonana. J Proteome Res 2016; 15:1649-58. [PMID: 27025989 DOI: 10.1021/acs.jproteome.6b00124] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
One of the hallmarks of marine diatom biology is their ability to cope with rapid changes in light availability due to mixing of the water column and the lens effect. We investigated how irradiance fluctuations influence the relative abundance of key photosynthetic proteins in the centric diatom Thalassiosira pseudonana by means of mass-spectrometry-based approaches for relative protein quantitation. Most notably, fluctuating-light conditions lead to a substantial overall up-regulation of light-harvesting complex proteins as well as several subunits of photosystems II and I. Despite an initial delay in growth under FL, there were no indications of FL-induced photosynthesis limitation, in contrast to other photosynthetic organisms. Our findings further strengthen the notion that diatoms use a qualitatively different mechanism of photosynthetic regulation in which chloroplast-mitochondria interaction has overtaken crucial regulatory processes of photosynthetic light reactions that are typical for the survival of land plants, green algae, and cyanobacteria.
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Affiliation(s)
- Irina Grouneva
- Department of Biochemistry, Molecular Plant Biology, University of Turku , Turku, FI-20520, Finland
| | - Dorota Muth-Pawlak
- Department of Biochemistry, Molecular Plant Biology, University of Turku , Turku, FI-20520, Finland
| | - Natalia Battchikova
- Department of Biochemistry, Molecular Plant Biology, University of Turku , Turku, FI-20520, Finland
| | - Eva-Mari Aro
- Department of Biochemistry, Molecular Plant Biology, University of Turku , Turku, FI-20520, Finland
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Central role for ferritin in the day/night regulation of iron homeostasis in marine phytoplankton. Proc Natl Acad Sci U S A 2015; 112:14652-7. [PMID: 26553998 DOI: 10.1073/pnas.1506074112] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In large regions of the open ocean, iron is a limiting resource for phytoplankton. The reduction of iron quota and the recycling of internal iron pools are among the diverse strategies that phytoplankton have evolved to allow them to grow under chronically low ambient iron levels. Phytoplankton species also have evolved strategies to cope with sporadic iron supply such as long-term storage of iron in ferritin. In the picophytoplanktonic species Ostreococcus we report evidence from observations both in the field and in laboratory cultures that ferritin and the main iron-binding proteins involved in photosynthesis and nitrate assimilation pathways show opposite diurnal expression patterns, with ferritin being maximally expressed during the night. Biochemical and physiological experiments using a ferritin knock-out line subsequently revealed that this protein plays a central role in the diel regulation of iron uptake and recycling and that this regulation of iron homeostasis is essential for cell survival under iron limitation.
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38
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Muhseen ZT, Xiong Q, Chen Z, Ge F. Proteomics studies on stress responses in diatoms. Proteomics 2015; 15:3943-53. [PMID: 26364674 DOI: 10.1002/pmic.201500165] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 08/09/2015] [Accepted: 09/09/2015] [Indexed: 01/09/2023]
Abstract
Diatoms are a highly diverse group of eukaryotic phytoplankton that are distributed throughout marine and freshwater environments and are believed to be responsible for approximately 40% of the total marine primary productivity. The ecological success of diatoms suggests that they have developed a range of strategies to cope with various biotic and abiotic stress factors. It is of great interest to understand the adaptive responses of diatoms to different stresses in the marine environment. Proteomic technologies have been applied to the adaptive responses of marine diatoms under different growth conditions in recent years such as nitrogen starvation, iron limitation and phosphorus deficiency. These studies have provided clues to elucidate the sophisticated sensing mechanisms that control their adaptive responses. Although only a very limited number of proteomic studies were conducted in diatoms, the obtained data have led to a better understanding of the biochemical processes that contribute to their ecological success. This review presents the current status of proteomic studies of diatom stress responses and discusses the novel developments and applications for the analysis of protein post-translational modification in diatoms. The potential future application of proteomics could contribute to a better understanding of the physiological mechanisms underlying diatom acclimation to a given stress and the acquisition of an enhanced diatom stress tolerance. Future challenges and research opportunities in the proteomics studies of diatoms are also discussed.
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Affiliation(s)
- Ziyad Tariq Muhseen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P. R. China.,University of Chinese Academy of Sciences, Beijing, P. R. China
| | - Qian Xiong
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P. R. China
| | - Zhuo Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P. R. China
| | - Feng Ge
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P. R. China
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Chappell PD, Whitney LP, Wallace JR, Darer AI, Jean-Charles S, Jenkins BD. Genetic indicators of iron limitation in wild populations of Thalassiosira oceanica from the northeast Pacific Ocean. THE ISME JOURNAL 2015; 9:592-602. [PMID: 25333460 PMCID: PMC4331588 DOI: 10.1038/ismej.2014.171] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 05/15/2014] [Accepted: 07/11/2014] [Indexed: 11/18/2022]
Abstract
Assessing the iron (Fe) nutritional status of natural diatom populations has proven challenging as physiological and molecular responses can differ in diatoms of the same genus. We evaluated expression of genes encoding flavodoxin (FLDA1) and an Fe-starvation induced protein (ISIP3) as indicators of Fe limitation in the marine diatom Thalassiosira oceanica. The specificity of the response to Fe limitation was tested in cultures grown under Fe- and macronutrient-deficient conditions, as well as throughout the diurnal light cycle. Both genes showed a robust and specific response to Fe limitation in laboratory cultures and were detected in small volume samples collected from the northeast Pacific, demonstrating the sensitivity of this method. Overall, FLDA1 and ISIP3 expression was inversely related to Fe concentrations and offered insight into the Fe nutritional health of T. oceanica in the field. As T. oceanica is a species tolerant to low Fe, indications of Fe limitation in T. oceanica populations may serve as a proxy for severe Fe stress in the overall diatom community. At two shallow coastal locations, FLD1A and ISIP3 expression revealed Fe stress in areas where dissolved Fe concentrations were high, demonstrating that this approach may be powerful for identifying regions where Fe supply may not be biologically available.
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Affiliation(s)
- P Dreux Chappell
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI, USA
| | - LeAnn P Whitney
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI, USA
| | - Joselynn R Wallace
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI, USA
| | - Adam I Darer
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, USA
| | - Samua Jean-Charles
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI, USA
| | - Bethany D Jenkins
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI, USA
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, USA
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40
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Luo CS, Liang JR, Lin Q, Li C, Bowler C, Anderson DM, Wang P, Wang XW, Gao YH. Cellular responses associated with ROS production and cell fate decision in early stress response to iron limitation in the diatom Thalassiosira pseudonana. J Proteome Res 2014; 13:5510-23. [PMID: 25372880 PMCID: PMC4261981 DOI: 10.1021/pr5004664] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Investigation of how diatoms cope with the rapid fluctuations in iron bioavailability in marine environments may facilitate a better understanding of the mechanisms underlying their ecological success, in particular their ability to proliferate rapidly during favorable conditions. In this study, using in vivo biochemical markers and whole-cell iTRAQ-based proteomics analysis, we explored the cellular responses associated with reactive oxygen species (ROS) production and cell fate decision during the early response to Fe limitation in the centric diatom Thalassiosira pseudonana. Fe limitation caused a significant decrease in Photosystem (PS) II photosynthetic efficiency, damage to the photosynthetic electron transport chain in PS I, and blockage of the respiratory chain in complexes III and IV, which could all result in excess ROS accumulation. The increase in ROS likely triggered programmed cell death (PCD) in some of the Fe-limited cells through synthesis of a series of proteins involved in the delicate balance between pro-survival and pro-PCD factors. The results provide molecular-level insights into the major strategies that may be employed by T. pseudonana in response to Fe-limitation: the reduction of cell population density through PCD to reduce competition for available Fe, the reallocation of intracellular nitrogen and Fe to ensure survival, and an increase in expression of antioxidant and anti-PCD proteins to cope with stress.
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Affiliation(s)
- Chun-Shan Luo
- School of Life Sciences, Xiamen University , Xiamen 361102, People's Republic of China
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Palenik B. Molecular mechanisms by which marine phytoplankton respond to their dynamic chemical environment. ANNUAL REVIEW OF MARINE SCIENCE 2014; 7:325-340. [PMID: 25195866 DOI: 10.1146/annurev-marine-010814-015639] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Marine scientists have long been interested in the interactions of marine phytoplankton with their chemical environments. Nutrient availability clearly controls carbon fixation on a global scale, but the interactions between phytoplankton and nutrients are complex and include both short-term responses (seconds to minutes) and longer-term evolutionary adaptations. This review outlines how genomics and functional genomics approaches are providing a better understanding of these complex interactions, especially for cyanobacteria and diatoms, for which the genome sequences of multiple model organisms are available. Transporters and related genes are emerging as the most likely candidates for biomarkers in stress-specific studies, but other genes are also possible candidates. One surprise has been the important role of horizontal gene transfer in mediating chemical-biological interactions.
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Affiliation(s)
- Brian Palenik
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0202;
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Poulson-Ellestad KL, Jones CM, Roy J, Viant MR, Fernández FM, Kubanek J, Nunn BL. Metabolomics and proteomics reveal impacts of chemically mediated competition on marine plankton. Proc Natl Acad Sci U S A 2014; 111:9009-14. [PMID: 24889616 PMCID: PMC4066504 DOI: 10.1073/pnas.1402130111] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Competition is a major force structuring marine planktonic communities. The release of compounds that inhibit competitors, a process known as allelopathy, may play a role in the maintenance of large blooms of the red-tide dinoflagellate Karenia brevis, which produces potent neurotoxins that negatively impact coastal marine ecosystems. K. brevis is variably allelopathic to multiple competitors, typically causing sublethal suppression of growth. We used metabolomic and proteomic analyses to investigate the role of chemically mediated ecological interactions between K. brevis and two diatom competitors, Asterionellopsis glacialis and Thalassiosira pseudonana. The impact of K. brevis allelopathy on competitor physiology was reflected in the metabolomes and expressed proteomes of both diatoms, although the diatom that co-occurs with K. brevis blooms (A. glacialis) exhibited more robust metabolism in response to K. brevis. The observed partial resistance of A. glacialis to allelopathy may be a result of its frequent exposure to K. brevis blooms in the Gulf of Mexico. For the more sensitive diatom, T. pseudonana, which may not have had opportunity to evolve resistance to K. brevis, allelopathy disrupted energy metabolism and impeded cellular protection mechanisms including altered cell membrane components, inhibited osmoregulation, and increased oxidative stress. Allelopathic compounds appear to target multiple physiological pathways in sensitive competitors, demonstrating that chemical cues in the plankton have the potential to alter large-scale ecosystem processes including primary production and nutrient cycling.
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Affiliation(s)
- Kelsey L Poulson-Ellestad
- School of Biology, Aquatic Chemical Ecology Center, Georgia Institute of Technology, Atlanta, GA 30332;Institute of Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Christina M Jones
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332
| | - Jessie Roy
- School of Biology, Aquatic Chemical Ecology Center, Georgia Institute of Technology, Atlanta, GA 30332;Institute of Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Mark R Viant
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom; and
| | - Facundo M Fernández
- Institute of Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332;School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332
| | - Julia Kubanek
- School of Biology, Aquatic Chemical Ecology Center, Georgia Institute of Technology, Atlanta, GA 30332;Institute of Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332;School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332;
| | - Brook L Nunn
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
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Kettles NL, Kopriva S, Malin G. Insights into the regulation of DMSP synthesis in the diatom Thalassiosira pseudonana through APR activity, proteomics and gene expression analyses on cells acclimating to changes in salinity, light and nitrogen. PLoS One 2014; 9:e94795. [PMID: 24733415 PMCID: PMC3986220 DOI: 10.1371/journal.pone.0094795] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 03/20/2014] [Indexed: 01/05/2023] Open
Abstract
Despite the importance of dimethylsulphoniopropionate (DMSP) in the global sulphur cycle and climate regulation, the biological pathways underpinning its synthesis in marine phytoplankton remain poorly understood. The intracellular concentration of DMSP increases with increased salinity, increased light intensity and nitrogen starvation in the diatom Thalassiosira pseudonana. We used these conditions to investigate DMSP synthesis at the cellular level via analysis of enzyme activity, gene expression and proteome comparison. The activity of the key sulphur assimilatory enzyme, adenosine 5′-phosphosulphate reductase was not coordinated with increasing intracellular DMSP concentration. Under all three treatments coordination in the expression of sulphur assimilation genes was limited to increases in sulphite reductase transcripts. Similarly, proteomic 2D gel analysis only revealed an increase in phosphoenolpyruvate carboxylase following increases in DMSP concentration. Our findings suggest that increased sulphur assimilation might not be required for increased DMSP synthesis, instead the availability of carbon and nitrogen substrates may be important in the regulation of this pathway. This contrasts with the regulation of sulphur metabolism in higher plants, which generally involves up-regulation of several sulphur assimilatory enzymes. In T. pseudonana changes relating to sulphur metabolism were specific to the individual treatments and, given that little coordination was seen in transcript and protein responses across the three growth conditions, different patterns of regulation might be responsible for the increase in DMSP concentration seen under each treatment.
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Affiliation(s)
- Nicola Louise Kettles
- Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
- John Innes Centre, Norwich, United Kingdom
| | | | - Gill Malin
- Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
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