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Li Z, Sun L, Liu S, Lei P, Wang R, Li S, Gu Y. Interkingdom network analyses reveal microalgae and protostomes as keystone taxa involved in nutrient cycling in large freshwater lake sediment. FEMS Microbiol Ecol 2023; 99:fiad111. [PMID: 37715306 DOI: 10.1093/femsec/fiad111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/26/2023] [Accepted: 09/14/2023] [Indexed: 09/17/2023] Open
Abstract
Few studies have explored the role of interkingdom interactions between bacteria and microeukaryotes in nutrient cycling in lake ecosystems. We conducted sediment sampling from 40 locations covering Hongze Lake and analyzed their chemical properties. Intra- and interkingdom networks were constructed using 16S and 18S rRNA gene amplicon sequencing. Microeukaryotic intranetworks were more complex in spring than in autumn, while no clear variation in the complexity of bacterial intranetworks was found between autumn and spring. Larger and more complex bacterial-microeukaryotic bipartite networks emerged in spring than in autumn, correlated with lower carbon, nitrogen, and phosphorus levels in spring, likely resulting in intense microbial competition. Bacteria and microeukaryotes played different topological roles in interkingdom networks, with microeukaryotes contributing to the networks' greater complexity. Seven keystone modules were identified in spring and autumn nutrient cycling. Importantly, keystone taxa in these modules belonged to photoautotrophic microalgae or predatory protostomes, indicating that these organisms are key drivers in lake sediment nutrient cycling. Our results suggested that nutrient content variation in autumn and spring changes interkingdom networks' topological structure between bacteria and microeukaryotes. Microalgae and protostomes are essential in freshwater lake nutrient cycling and may be targeted to modulate nutrient cycling in large freshwater ecosystems.
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Affiliation(s)
- Zhidan Li
- College of Biological and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, P.R. China
| | - Liang Sun
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China
| | - Sijie Liu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China
| | - Peng Lei
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China
| | - Rui Wang
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China
| | - Sha Li
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China
| | - Yian Gu
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China
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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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Gao X, Bowler C, Kazamia E. Iron metabolism strategies in diatoms. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:2165-2180. [PMID: 33693565 PMCID: PMC7966952 DOI: 10.1093/jxb/eraa575] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 03/03/2021] [Indexed: 05/28/2023]
Abstract
Diatoms are one of the most successful group of photosynthetic eukaryotes in the contemporary ocean. They are ubiquitously distributed and are the most abundant primary producers in polar waters. Equally remarkable is their ability to tolerate iron deprivation and respond to periodic iron fertilization. Despite their relatively large cell sizes, diatoms tolerate iron limitation and frequently dominate iron-stimulated phytoplankton blooms, both natural and artificial. Here, we review the main iron use strategies of diatoms, including their ability to assimilate and store a range of iron sources, and the adaptations of their photosynthetic machinery and architecture to iron deprivation. Our synthesis relies on published literature and is complemented by a search of 82 diatom transcriptomes, including information collected from seven representatives of the most abundant diatom genera in the world's oceans.
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Affiliation(s)
- Xia Gao
- Institut de Biologie de l’ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Chris Bowler
- Institut de Biologie de l’ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Elena Kazamia
- Institut de Biologie de l’ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
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Bozzato D, Jakob T, Wilhelm C, Trimborn S. Effects of iron limitation on carbon balance and photophysiology of the Antarctic diatom Chaetoceros cf. simplex. Polar Biol 2021. [DOI: 10.1007/s00300-020-02785-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
AbstractIn the Southern Ocean (SO), iron (Fe) limitation strongly inhibits phytoplankton growth and generally decreases their primary productivity. Diatoms are a key component in the carbon (C) cycle, by taking up large amounts of anthropogenic CO2 through the biological carbon pump. In this study, we investigated the effects of Fe availability (no Fe and 4 nM FeCl3 addition) on the physiology of Chaetoceros cf. simplex, an ecologically relevant SO diatom. Our results are the first combining oxygen evolution and uptake rates with particulate organic carbon (POC) build up, pigments, photophysiological parameters and intracellular trace metal (TM) quotas in an Fe-deficient Antarctic diatom. Decreases in both oxygen evolution (through photosynthesis, P) and uptake (respiration, R) coincided with a lowered growth rate of Fe-deficient cells. In addition, cells displayed reduced electron transport rates (ETR) and chlorophyll a (Chla) content, resulting in reduced cellular POC formation. Interestingly, no differences were observed in non-photochemical quenching (NPQ) or in the ratio of gross photosynthesis to respiration (GP:R). Furthermore, TM quotas were measured, which represent an important and rarely quantified parameter in previous studies. Cellular quotas of manganese, zinc, cobalt and copper remained unchanged while Fe quotas of Fe-deficient cells were reduced by 60% compared with High Fe cells. Based on our data, Fe-deficient Chaetoceros cf. simplex cells were able to efficiently acclimate to low Fe conditions, reducing their intracellular Fe concentrations, the number of functional reaction centers of photosystem II (RCII) and photosynthetic rates, thus avoiding light absorption rather than dissipating the energy through NPQ. Our results demonstrate how Chaetoceros cf. simplex can adapt their physiology to lowered assimilatory metabolism by decreasing respiratory losses.
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Sutak R, Camadro JM, Lesuisse E. Iron Uptake Mechanisms in Marine Phytoplankton. Front Microbiol 2020; 11:566691. [PMID: 33250865 PMCID: PMC7676907 DOI: 10.3389/fmicb.2020.566691] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 10/19/2020] [Indexed: 12/20/2022] Open
Abstract
Oceanic phytoplankton species have highly efficient mechanisms of iron acquisition, as they can take up iron from environments in which it is present at subnanomolar concentrations. In eukaryotes, three main models were proposed for iron transport into the cells by first studying the kinetics of iron uptake in different algal species and then, more recently, by using modern biological techniques on the model diatom Phaeodactylum tricornutum. In the first model, the rate of uptake is dependent on the concentration of unchelated Fe species, and is thus limited thermodynamically. Iron is transported by endocytosis after carbonate-dependent binding of Fe(III)' (inorganic soluble ferric species) to phytotransferrin at the cell surface. In this strategy the cells are able to take up iron from very low iron concentration. In an alternative model, kinetically limited for iron acquisition, the extracellular reduction of all iron species (including Fe') is a prerequisite for iron acquisition. This strategy allows the cells to take up iron from a great variety of ferric species. In a third model, hydroxamate siderophores can be transported by endocytosis (dependent on ISIP1) after binding to the FBP1 protein, and iron is released from the siderophores by FRE2-dependent reduction. In prokaryotes, one mechanism of iron uptake is based on the use of siderophores excreted by the cells. Iron-loaded siderophores are transported across the cell outer membrane via a TonB-dependent transporter (TBDT), and are then transported into the cells by an ABC transporter. Open ocean cyanobacteria do not excrete siderophores but can probably use siderophores produced by other organisms. In an alternative model, inorganic ferric species are transported through the outer membrane by TBDT or by porins, and are taken up by the ABC transporter system FutABC. Alternatively, ferric iron of the periplasmic space can be reduced by the alternative respiratory terminal oxidase (ARTO) and the ferrous ions can be transported by divalent metal transporters (FeoB or ZIP). After reoxidation, iron can be taken up by the high-affinity permease Ftr1.
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Affiliation(s)
- Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czechia
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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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Distribution of dissolved iron and bacteria producing the photoactive siderophore, vibrioferrin, in waters off Southern California and Northern Baja. Biometals 2019; 32:139-154. [PMID: 30623317 DOI: 10.1007/s10534-018-00163-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 12/07/2018] [Indexed: 12/14/2022]
Abstract
Phytoplankton blooms can cause acute effects on marine ecosystems due either to their production of endogenous toxins or to their enormous biomass leading to major impacts on local economies and public health. Despite years of effort, the causes of these Harmful Algal Blooms are still not fully understood. Our hypothesis is that bacteria that produce photoactive siderophores may provide a bioavailable source of iron for phytoplankton which could in turn stimulate algal growth and support bloom dynamics. Here we correlate iron concentrations, phytoplankton cell counts, bacterial cell abundance, and copy numbers for a photoactive siderophore vibrioferrin biosynthesis gene in water samples taken from 2017 cruises in the Gulf of California, and the Pacific Ocean off the coast of northern Baja California as well as during a multiyear sampling at Scripps Pier in San Diego, CA. We find that bacteria producing the photoactive siderophore vibrioferrin, make up a surprisingly high percentage of total bacteria in Pacific/Gulf of California coastal waters (up to 9%). Vibroferrin's unique properties and the widespread prevalence of its bacterial producers suggest that it may contribute significantly to generating bioavailability of iron via photoredox reactions.
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Moreno CM, Lin Y, Davies S, Monbureau E, Cassar N, Marchetti A. Examination of gene repertoires and physiological responses to iron and light limitation in Southern Ocean diatoms. Polar Biol 2017. [DOI: 10.1007/s00300-017-2228-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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9
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Iron incorporation in biosilica of the marine diatom Stephanopyxis turris: dispersed or clustered? Biometals 2017; 30:71-82. [PMID: 28064420 DOI: 10.1007/s10534-016-9987-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 12/21/2016] [Indexed: 01/08/2023]
Abstract
Iron incorporation into diatom biosilica was investigated for the species Stephanopyxis turris. It is known that several "foreign" elements (e.g., germanium, titanium, aluminum, zinc, iron) can be incorporated into the siliceous cell walls of diatoms in addition to silicon dioxide (SiO2). In order to examine the amount and form of iron incorporation, the iron content in the growth medium was varied during cultivation. Fe:Si ratios of isolated cell walls were measured by ICP-OES. SEM studies were performed to examine of a possible influence of excess iron during diatom growth upon cell wall formation. The chemical state of biosilica-attached iron was characterized by a combination of infrared, 29Si MAS NMR, and EPR spectroscopy. For comparison, synthetic silicagels of variable iron content were studied. Our investigations show that iron incorporation in biosilica is limited. More than 95% of biosilica-attached iron is found in the form of iron clusters/nanoparticles. In contrast, iron is preferentially dispersedly incorporated within the silica framework in synthetic silicagels leading to Si-O-Fe bond formation.
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Walworth NG, Fu FX, Webb EA, Saito MA, Moran D, Mcllvin MR, Lee MD, Hutchins DA. Mechanisms of increased Trichodesmium fitness under iron and phosphorus co-limitation in the present and future ocean. Nat Commun 2016; 7:12081. [PMID: 27346420 PMCID: PMC4931248 DOI: 10.1038/ncomms12081] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 05/27/2016] [Indexed: 02/07/2023] Open
Abstract
Nitrogen fixation by cyanobacteria supplies critical bioavailable nitrogen to marine ecosystems worldwide; however, field and lab data have demonstrated it to be limited by iron, phosphorus and/or CO2. To address unknown future interactions among these factors, we grew the nitrogen-fixing cyanobacterium Trichodesmium for 1 year under Fe/P co-limitation following 7 years of both low and high CO2 selection. Fe/P co-limited cell lines demonstrated a complex cellular response including increased growth rates, broad proteome restructuring and cell size reductions relative to steady-state growth limited by either Fe or P alone. Fe/P co-limitation increased abundance of a protein containing a conserved domain previously implicated in cell size regulation, suggesting a similar role in Trichodesmium. Increased CO2 further induced nutrient-limited proteome shifts in widespread core metabolisms. Our results thus suggest that N2-fixing microbes may be significantly impacted by interactions between elevated CO2 and nutrient limitation, with broad implications for global biogeochemical cycles in the future ocean. Cyanobacterial nitrogen fixation supplies bioavailable nitrogen to marine ecosystems, but the mechanisms governing iron and phosphorus co-limitation in elevated CO2 remain unknown. Here, the authors show a complex cellular response to co-limitation characterized by changes in growth, cell size, and the proteome.
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Affiliation(s)
- Nathan G Walworth
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, California 90089, USA
| | - Fei-Xue Fu
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, California 90089, USA
| | - Eric A Webb
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, California 90089, USA
| | - Mak A Saito
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - Dawn Moran
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - Matthew R Mcllvin
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
| | - Michael D Lee
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, California 90089, USA
| | - David A Hutchins
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, California 90089, USA
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Abstract
Ferritins, the main intracellular iron storage proteins, have been studied for over 60 years, mainly focusing on the mammalian ones. This allowed the elucidation of the structure of these proteins and the mechanisms regulating their iron incorporation and mineralization. However, ferritin is present in most, although not all, eukaryotic cells, comprising monocellular and multicellular invertebrates and vertebrates. The aim of this review is to provide an update on the general properties of ferritins that are common to various eukaryotic phyla (except plants), and to give an overview on the structure, function and regulation of ferritins. An update on the animal models that were used to characterize H, L and mitochondrial ferritins is also provided. The data show that ferritin structure is highly conserved among different phyla. It exerts an important cytoprotective function against oxidative damage and plays a role in innate immunity, where it also contributes to prevent parenchymal tissue from the cytotoxicity of pro-inflammatory agonists released by the activation of the immune response activation. Less clear are the properties of the secretory ferritins expressed by insects and molluscs, which may be important for understanding the role played by serum ferritin in mammals.
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Gügi B, Le Costaouec T, Burel C, Lerouge P, Helbert W, Bardor M. Diatom-Specific Oligosaccharide and Polysaccharide Structures Help to Unravel Biosynthetic Capabilities in Diatoms. Mar Drugs 2015; 13:5993-6018. [PMID: 26393622 PMCID: PMC4584364 DOI: 10.3390/md13095993] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 12/12/2022] Open
Abstract
Diatoms are marine organisms that represent one of the most important sources of biomass in the ocean, accounting for about 40% of marine primary production, and in the biosphere, contributing up to 20% of global CO₂ fixation. There has been a recent surge in developing the use of diatoms as a source of bioactive compounds in the food and cosmetic industries. In addition, the potential of diatoms such as Phaeodactylum tricornutum as cell factories for the production of biopharmaceuticals is currently under evaluation. These biotechnological applications require a comprehensive understanding of the sugar biosynthesis pathways that operate in diatoms. Here, we review diatom glycan and polysaccharide structures, thus revealing their sugar biosynthesis capabilities.
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Affiliation(s)
- Bruno Gügi
- Laboratoire Glyco-MEV EA 4358, Université de Rouen, Normandie Université, Institut de Recherche et d'Innovation Biomédicale (IRIB), Végétale Agronomie Sol Innovation (VASI), Normandie Université, Faculté des Sciences et Techniques, 76821 Mont-Saint-Aignan, France.
| | - Tinaïg Le Costaouec
- CNRS, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Grenoble Alpes, CERMAV, F-38000 Grenoble, France.
| | - Carole Burel
- Laboratoire Glyco-MEV EA 4358, Université de Rouen, Normandie Université, Institut de Recherche et d'Innovation Biomédicale (IRIB), Végétale Agronomie Sol Innovation (VASI), Normandie Université, Faculté des Sciences et Techniques, 76821 Mont-Saint-Aignan, France.
| | - Patrice Lerouge
- Laboratoire Glyco-MEV EA 4358, Université de Rouen, Normandie Université, Institut de Recherche et d'Innovation Biomédicale (IRIB), Végétale Agronomie Sol Innovation (VASI), Normandie Université, Faculté des Sciences et Techniques, 76821 Mont-Saint-Aignan, France.
| | - William Helbert
- CNRS, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Grenoble Alpes, CERMAV, F-38000 Grenoble, France.
| | - Muriel Bardor
- Laboratoire Glyco-MEV EA 4358, Université de Rouen, Normandie Université, Institut de Recherche et d'Innovation Biomédicale (IRIB), Végétale Agronomie Sol Innovation (VASI), Normandie Université, Faculté des Sciences et Techniques, 76821 Mont-Saint-Aignan, France.
- Institut Universitaire de France (IUF), 75005 Paris, France.
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Diversity and Evolutionary History of Iron Metabolism Genes in Diatoms. PLoS One 2015; 10:e0129081. [PMID: 26052941 PMCID: PMC4460010 DOI: 10.1371/journal.pone.0129081] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 05/05/2015] [Indexed: 01/04/2023] Open
Abstract
Ferroproteins arose early in Earth’s history, prior to the emergence of oxygenic photosynthesis and the subsequent reduction of bioavailable iron. Today, iron availability limits primary productivity in about 30% of the world’s oceans. Diatoms, responsible for nearly half of oceanic primary production, have evolved molecular strategies for coping with variable iron concentrations. Our understanding of the evolutionary breadth of these strategies has been restricted by the limited number of species for which molecular sequence data is available. To uncover the diversity of strategies marine diatoms employ to meet cellular iron demands, we analyzed 367 newly released marine microbial eukaryotic transcriptomes, which include 47 diatom species. We focused on genes encoding proteins previously identified as having a role in iron management: iron uptake (high-affinity ferric reductase, multi-copper oxidase, and Fe(III) permease); iron storage (ferritin); iron-induced protein substitutions (flavodoxin/ferredoxin, and plastocyanin/cytochrome c6) and defense against reactive oxygen species (superoxide dismutases). Homologs encoding the high-affinity iron uptake system components were detected across the four diatom Classes suggesting an ancient origin for this pathway. Ferritin transcripts were also detected in all Classes, revealing a more widespread utilization of ferritin throughout diatoms than previously recognized. Flavodoxin and plastocyanin transcripts indicate possible alternative redox metal strategies. Predicted localization signals for ferredoxin identify multiple examples of gene transfer from the plastid to the nuclear genome. Transcripts encoding four superoxide dismutase metalloforms were detected, including a putative nickel-coordinating isozyme. Taken together, our results suggest that the majority of iron metabolism genes in diatoms appear to be vertically inherited with functional diversity achieved via possible neofunctionalization of paralogs. This refined view of iron use strategies in diatoms elucidates the history of these adaptations, and provides potential molecular markers for determining the iron nutritional status of different diatom species in environmental samples.
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Sharon S, Salomon E, Kranzler C, Lis H, Lehmann R, Georg J, Zer H, Hess WR, Keren N. The hierarchy of transition metal homeostasis: Iron controls manganese accumulation in a unicellular cyanobacterium. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1990-1997. [DOI: 10.1016/j.bbabio.2014.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 09/17/2014] [Accepted: 09/18/2014] [Indexed: 01/04/2023]
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Carmel N, Tel-Or E, Chen Y, Pick U. Iron uptake mechanism in the chrysophyte microalga Dinobryon. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:993-997. [PMID: 24974325 DOI: 10.1016/j.jplph.2014.03.014] [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: 09/12/2013] [Revised: 03/29/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
The mechanism of iron uptake in the chrysophyte microalga Dinobryon was studied. Previous studies have shown that iron is the dominant limiting elements for growth of Dinobryon in the Eshkol reservoir in northern Israel, which control its burst of bloom. It is demonstrated that Dinobryon has a light-stimulated ferrireductase activity, which is sensitive to the photosynthetic electron transport inhibitor DCMU and to the uncoupler CCCP. Iron uptake is also light-dependent, is inhibited by DCMU and by CCCP and also by the ferrous iron chelator BPDS. These results suggest that ferric iron reduction by ferrireductase is involved in iron uptake in Dinobryon and that photosynthesis provides the major reducing power to energize iron acquisition. Iron deprivation does not enhance but rather inhibits iron uptake contrary to observations in other algae.
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Affiliation(s)
- Nava Carmel
- Department of Agricultural Botany, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel
| | - Elisha Tel-Or
- Department of Agricultural Botany, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel.
| | - Yona Chen
- Department of Soil and Water Sciences, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel
| | - Uri Pick
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel.
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Raven JA. RNA function and phosphorus use by photosynthetic organisms. FRONTIERS IN PLANT SCIENCE 2013; 4:536. [PMID: 24421782 PMCID: PMC3872737 DOI: 10.3389/fpls.2013.00536] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 12/11/2013] [Indexed: 05/03/2023]
Abstract
Phosphorus (P) in RNA accounts for half or more of the total non-storage P in oxygenic photolithotrophs grown in either P-replete or P-limiting growth conditions. Since many natural environments are P-limited for photosynthetic primary productivity, and peak phosphorus fertilizer production is inevitable, the paper analyses what economies in P allocation to RNA could, in principle, increase P-use efficiency of growth (rate of dry matter production per unit organism P). The possibilities of decreasing P allocation to RNA without decreasing growth rate include (1) more widespread down-regulation of RNA production in P-limited organisms, (2) optimal allocation of P to RNA, both spatially among cell compartments and organs, and temporally depending on the stage of growth, and (3) a constant rate of protein synthesis through the diel cycle. Acting on these suggestions would, however, be technically demanding.
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Affiliation(s)
- John A. Raven
- Division of Plant Science, University of Dundee at the James Hutton InstituteDundee, UK
- School of Plant Biology, University of Western AustraliaPerth, WA, Australia
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